Adrian I think you did very well if this was one of your first times. I've been doing SMD repairs for a few years, and I would just give you a couple tips - Use a good quality tacky flux (MG Chemicals, Amtech, etc), It will actually help keep the component in place, it wont get boiled off so quickly, and if you use enough flux the surface tension and heat will often line up the chip perfectly for you. When you remove the chip, clean the original solder off the pads and apply new solder, it's just good practice. Also, if you eventually end up doing more SMD work, I would invest in a decent hot air station. Those cheap $40-$80 units with random names on them that are all over Amazon, Ebay, etc. do not have nearly as good thermal capacity as something like a name brand Quick 857DW+ that only costs a few dollars more. Also those cheap hot air stations scare me. There are way too many videos and personal experiences from people who have had them randomly melt down and catch fire right there on the bench. I always recommend that if people have to buy those things, definitely take it apart and inspect it. About half the time the mains input is accidentally wired backwards into the power switch and board and the station will still work like this but it is an absolute safety hazard. The quality control on those things is abysmal.
I admire Adrian's honesty by putting this online! I have a few constructive tips to add.. The desoldering nozzle was too small. The nozzle needs to be about the same size as the device that's being lifted, rather than struggling by dancing around the chip, and risk pulling a pad or a trace as you tug on the device. (For multilayer and/or large boards, the thermal mass is much higher so will take a while to start melting the solder: some use a board preheater, but for a board of this size there's no need). Another trick in removal is to tin the leads & pads with leaded solder while the part's still on the board to bring the melting temp down, or, even easier, use low temp repair solder like ChipQuik alloy. The same comment about nozzle size applies to placing too when using reflow: it needs to have simultaneous heat coverage over the entire device. Dancing around the chip with a small nozzle is going to end up... well, we saw how it ends up! For placing leaded parts like this, I use drag soldering for small pitches under 0.8mm, but the part here has a pitch large enough that they could reasonably easily be hand soldered. Anchor the part with a couple of diametrically opposite pins before drag or pin-by-pin soldering. With drag soldering, you have to accept that however hard you try you'll end up bridging pins at some stage. If you're going to hand solder by dragging or pin by pin rather than reflow, then you really should to clean the pads first. I keep two thicknesses of wick available, and two thicknesses of solder on the bench. I don't know what the purpose was of adding solder directly to the tip of the iron. The pads can be re-tinned applying small amounts of solder to the pads as necessary as the iron traverses the pre-fluxed pads. I use a stereo optical zoom microscope, the digital microscopes add latency and lack spatial dimension. One further trick about checking pin continuity when the board is otherwise empty, for example with breakout boards: as well as adjacent pin short check, you can usually also check for pin connectivity to the board by using a DMM with an audible diode check; hold the + probe on a ground pin, and buzz out the other pins, using the protection diodes.
Yeah, I really think Adrian's problems were that he didn't clean the board and put the chip down directly on the pads, THEN add solder to a couple of pins to tack it down and go from there. What I know about SMD soldering is that it's always about mess control. You make one when/where you need to, and clean it up any time you have the opportunity. You use a lot of flux, a lot of solder wick, and a little more solder … but it's a lot less flustration that way.
you cannot "wire it backwards", main power (mostly) is a 2 prong plug that you can plug in any way you want in Europe. I do not think, even if you are in other countries, that power will work differently there ;)
After removing the old IC you also have to remove the old tin with the stranded wire. Then the IC lies flat. Solder two corners with a little tin with the soldering iron, it doesn't have to be pretty, the IC just has to be straight. Then use a soldering iron to solder the pins with a lot of flux and a moderate amount of tin. If a bridge appears, ignore it, strip the soldering iron and use fresh tin moderately. Always give the IC some time to cool down and don't constantly re-solder yourself in one place and over heat. Allow to cool, breathe deeply, or take a break and try again if it's cold again. I can't solder much better, but you'll get practice with time. Good job Adrian
I've been working with SMD and BGA soldering for a living for 11 years now, and I think that the easiest way to solder QFPs like this is to NOT remove old solder from the board, but this works only if you use paste flux and if your IC pins aren't oxidized. Most paste fluxes will work but you'll save yourself from headdaches if you'll use good flux (I can recommend FluxPlus 6-411-A or 6-412-A, one of the best fluxes that I used). The process goes like this: 1) Apply some flux on the pins of the IC you want to desolder. You don't need to use much, but at this point it is not important, you can add as much as you like, just make sure that the flux covers all the pins (I mean the bottom part of the pins which is soldered to PCB, not the whole pin) and space between pins. 2) On you hot air fan use a noozle that is near the size or a little bigger than the IC you want to desolder. This will guarantee that when solder will start to melt all of the pins will stay melted and not become solid again. To not overheat the IC don't hold the hot air fan in one place, move it around in cilrcular motion, but not too quick or it will take much more time to heat the solder. 3) When the solder on all the pins have melted remove the IC from the board by grabbing it with fine tweezers from the corner with one half of the tweezers put under and one on top of the IC. Be careful to not move the IC around the board. After you remove the IC this way the solder on the pads on the PCB will be distributed evenly and the shape of the blobs will be close to identical. 4) Let the board cool down. After it's cooled remove flux residue using some kind of solvent (I use Electro Degreaser by Cramolin, my colleagues just use acetone), you can use isopropyl alcohol but solvent does much better. Wipe it using a piece of thin cloth soaked in solvent or use a toothbrush. Remove excessive solvent using a dry piece of cloth. When your board is cleaned add fresh flux on all the pads. This time don't use to much flux, because when it'll boil it can move the IC around. Once again, add enough so it'll cover all the pads when melted. 5) Carefully position your IC on top of the solder blobs that are left on the solder pads. This is not an easy process and somewhat tedious. your positioning don't need to be 100% accurate, just make sure that pins are not laying between pads, they need to be on top of the solder blobs. 6) Don't hold the IC in place, just heat it using hot air fan but be sure to hold it the fan perpendicularly to the board and don't use too much airflow to not blow the ic off its position. Again, use circular motions. When the solder will melt your IC will, firstly, tin itself and, secondly, position itself on the solder pads. After this is done cool off the board and clean it using solvent and a toothbrush. 7) Check that all the pins are properly soldered using a needle or fine tweezer - just lightly drag the needle on top of the soldered parts of the pins, if any pin isn't properly soldered it'll bend a little which'll be immediatly noticeable. If there'll be some unsoldered pins then you can solder them using a little flux and a soldering iron. Don't add new solder if there's enough old solder on the pad, this is to ensure that you don't short adjacent pins. Most of the time this technique gives near factory level soldering quality, but you need some practice to get it right.
FWVLIW: Everyone struggles with SMD soldering when moving from through-hole. Much of the struggle is a matter of mindset. Through-hole - You're not so bothered about accurate component placement but you want to be accurate with your soldering. SMD - You want to be very accurate with your component placement but as long as you use plenty of the right flux you don't care about the accuracy of your soldering - surface tension will take care of it as long as you use it rather than fight it. Three basic techniques: (Always start with clean pads and use SMD-apocopate flux. For the most part use one technique or the other!) 1) Use a soldering iron to dab / drag your solder for affixing pins. Don't pre-tin!!! 2) Use hot air to melt your part(s) on to their pre-tinned (or preferably solder pasted) pads - a little shimmy will let you know the solder has melted. 3) Use something like a toaster-oven, pre-solder paste pads, pre-place parts, and let nature take it's course. -Either hold the part in place from the get-go or don't touch it at all! Touching a part you're in the middle of soldering will mess it up! -There will be solder bridges when soldering multi-pin packages - DO NOT use solder braid!!! Flux and a clean iron tip should be all you need. -Each to their own but many use a soldering iron for passive components and hot air (if they have it) for ICs with lots of legs -Option 3) is great if you're doing a lot of SMD soldering, a bit of a faff for single boards or short runs. Once you have the SMD mindset you'll be golden. Be warned, you'll probably find your through-hole soldering gets messier. I hope that helps somebody. Do what Adrian's doing and give it a go.
Yeah, I can approve your tip list. I always teach my students to consider first what technique they want to use to solder the part. When you use hot air soldering, there should be the right amount of flux on the board, then it does not matter which flux you take (surely not the one that evaporates quickly). If there is too much flux your ic will swim on the flux and will not make good contact with the solder. If there is the right amount, the flux will prevent shorting the pins and the surface tension will do the rest and DON'T touch the ic, it only misplaces your ic and you have to start again. Using QFP packages and a microscope I rather always use drag soldering, because you don't stress your ic so much and get it in place quickly and the cleaning afterwards is not that an efford. But Adrian good job for your first time soldering an smd ic. Do a little bit exercising, perhaps on old defect boards (soldering off an smd chip, clean it and solder it back on), then your next production board will be childs play.
What I learned from this video was just as valuable as watching Louis Rossman or NorthridgeFix. I learn more when things go wrong than when they go right. When things start to go outside of what you have learned about then it's easy to panic, and when I try this (and inevitably the same things happen) I will know not to panic, this is not unexpected given inexperience, and I just need to practice more.
+1 for Louis Rossmann, watching his videos got me into micro-soldering and the RGB2HDMI was my first SMD project. Leaded solder, decent amount of flux, a fine hot air nozzle and a microscope makes the job a cinch 🙂👍
I echo others comments in that oftentimes I learn more from when things go wrong, than watching a perfect tutorial. Thank you for posting this video! I've never tried SMD soldering, but now I have an idea of what can happen
exactly - I lerned more from replacing a GPU on a laptop then I did in school replacing components. Also what might be the easy or right way for some may not work for you, while the really hard way may seem easy.... I also found out I was old and needed a lot of magnafication to really see any missed connections and bridges -
Adrian, as a newbie enthusiast it’s wonderful to see someone so skilled have and share their learning opportunities! The honesty is refreshing and helps remind me and hopefully others we all have opportunities to grow and learn new skills.
As others have mentioned, the way I have succeeded in replacing QFP chips is to use hot air to remove it (including using aluminum tape to sheild surronding devices), clean off all the old flux and solder, put on some no clean flux, use a soldering iron to tack the corners and then all the other pins. remove bridges with solder braid. You ended up with the chip sittong on bumps of solder, which means its not flat to the pcb, which is why bridging was a issue. That said, the finished job was neat enough. Maybe get some broken cards and practice some!
You never claim to be an expert at anything and often make a point of saying you're not, but I continue to learn a huge amount from you. It's kind of refreshing to see you having difficulty with something I would usually be okay with, again really appreciate the humility in sharing your mistakes. As others have said, after the package was clear of the board I would have taken the old solder from the pads with wick and then cleaned with IPA, then approached it like a new board i.e. two corners first and then drag-solder the rest. I would only use hot air to solder components *in* if working with solder paste. Another trick I found was to use a sticky flux on the pads, carefully place the chip and then leave it to dry, then drag-solder the whole thing. This resulting in better alignment with the pads without bending any of the leads, making the drag soldering stage fairly easy and these were QFP-144 ICs with 0.5 mm pitch. Great to see you got it working though, all's well that ends well.
Thank you for making a video showing that even an inexperienced amateur with cheap no-brand equipment, can get somehing working! It is nice to see someone else trying and learning a new skill - and the comments are filling up with good advice and suggestions for everyone trying to learn! Nice!
Adrian, you did fine here, when I did this kind of work I always used air to remove and the iron to replace. I'd remove, clean up all pads so they're absolutely dry (no solder), flux, then do exactly what you did by tacking opposite corners, then I'd tack the remaining corners if I was 100% happy with the alignment, then I'd just solder all the legs with the iron. If you have something that can evenly heat the board slowly the chip would (usually!) align itself without doing it manually but I've also seen them turn and align crooked. For chips like this, especially for a hobbyist, air to remove, iron to replace :)
one thing I found really useful when I was learning to SMD solder is that there are some $10 all-SMD kits available from various little shenzhen brands which contain the parts for a 555-based blinking light circuit, and a bunch of extra SMD chip resistors/capacitors just for practice. I bought a couple of those and the first one was a write-off, but the second one helped me get my techniques down and even gave me a little experience troubleshooting! loved the video and looking forward to more from you soon.
Yeah, I got myself one of these that had passives down to 0402, some cylindrical components (they were the hardest), and some LEDs and transistors. It was a really good training exercise. The one I got had resistors down one side in series, and caps down the other side in parallel, with a couple of test points either end so you could put your multimeter on it and check the components summed to the correct values.
@@merseyviking Those round components are called 'Metal Electrode Leadless Face' (MELF). You need either two irons or soldering tweezers to do them properly. They were intended for automated assembly, with solder paste.
It's so honest of you to admit your shortcomings and share your learning experiences, even when your successes are so close to failure! I think this actually helped me. I've not done very well with SMD soldering myself and it's humbling to know that someone so experienced in working on PCBs in general can have the same problems as I. Moreover, the fact that you kept trying and made it through will be encouraging to many. Thanks for the inspiration!
This was absolutely a tutorial no matter what you said! I love how you've shown how wrong things can go if you've never done this sort of thing before. That you're comfortable showing your viewers you're not doing things perfectly the first time speak volumes - I really think seeing what not to do can be as educational as a 'proper' tutorial. Thanks dude.
Hey Adrian don't be too hard on yourself you did really well for your first time, my only suggestion would be use a bigger nozzle for a chip that size and a little more heat 380c, set the chip down and apply heat. once its flowing nudge it inplace, only hold down then for cooling. hope this helps.
Adrian. As a professional smd technician with 30ish years experience, it was 'entertaining' to watch. I love that you get in and have a go. I enjoy the channel alot.
You couldn't have titled this video better 🙂 You are very lucky that the CPLD survived this torture (your words, not mine, but I strongly agree.) Here are some pointers for the next time: 1) Always clean the pads of any solder and old flux COMPLETELY after removing an IC. DO NOT pre-fill the pads with new solder, they have to be absolutely flat (like a new PCB) to be able to seat the new IC properly and easily. 2) Before you seat the new IC, apply a a little paste flux on to the clean pads, DO NOT use liquid flux because it is like 95% alcohol and it will evaporate as soon as you apply any heat. The flux you put here will also act like a weak adhesive and will help to keep the IC in place later on. 3) Seat the new IC and make sure all the pins on all the sides are aligned perfectly, press the IC down firmly enough to keep it in place and apply a TON of paste flux on the pins. I can't stress the term "a ton of flux" more here, really put a stupid amount of it. See Louis Rossman's videos for the amount. 🙂 4) Take a chiseled tip iron, clean the tip well. Just add a tiny, tiny, tiny bit of solder on to the tip on the iron and tack down just one pin. You will be doing this with one hand with the other one still pressing down on the IC, so pick the easiest pin on one of the corners. Check that it took solder and it is soldered down. It doesn't matter if it is bridged or not soldered pretty, it is just an anchor for the time being. 5) Make sure the IC is still aligned, and do another pin on the opposite side, still pressing the IC down. 6) Now that your IC is properly held in place by 2 sides, you can do the rest of the pins, just add more flux paste to the areas it is melted away, clean the iron tip, and add a small amount of solder on it. How much is "small"? I hear you asking, well, exactly half of what you think it is. 7) Drag solder the pins on one side that isn't tacked down. Make sure you are touching just the tips (ends) of the pins, which means the tips that are touching the PCB. DO NOT touch the whole pin, that's how you get bridges. Touching just the pin ends is very important. It ensures less friction, less heat transfer to the IC body, better solder flow on to the PCB and under the pin. Now clean the iron tip again, put new solder on (now that you've discovered you actually put more than needed the first time, put less) , and do the opposite side, followed by the sides that you already have one pin tacked, cleaning the iron well and applying new solder before each side. 8) Clean the board with IPA of all the flux and check your work under magnification. If any pin looks suspicious to you, just apply flux (a ton) to the whole side and pass over all the pins on that side with a clean iron tip, no solder, again touching just the pin ends. This will re-do all pins on that side and distribute the solder that is already in evenly, taking care of small bridges. Clean the board again, check again until you like what you see.
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Not easy to install, but you own the right tools, so that is a good start. Always tape down the board with Kapton tape when installing the chip. Not doing this caused you a lot of pain.Use hot air to remove leaded SMD components. Take out all the solder with iron, solder braid and flux before installing the new chip. Use soldering iron with a small bevelled tip. Use very little solder (you added too much) and a lot of flux. Sweep on the pin tips and pads, not over the pins. otherwise you risk creating bridges on the slanted parts of the pins. Good luck!
You leaned, you laughed, you produced worthwhile content! This makes me feel better about my own skills seeing someone so proficient in so much struggling like I do.
Thank you for uploading this, it’s reassuring to see some reality for a change, which makes me feel better about my efforts! It can be quite demoralising watching an expert make something look very easy, then find yourself making a huge mess instead!
Kudos to you for your perseverance and sense of humor. I don't know the proper way to resolder a SMD device with multiple pins. The problem with using the "corner tack" method, like you did, is that the pins are being held up off the pads by the old solder.
If I may be captain obvious by adding like the 1 millionth likewise comment here... you were quite good, especially since you got the job done. Believe it or not, I've been performing SMT soldering for over 33 years as well as holding various IPC CIS and CIT certs (J-STD-001, A-610, 7711/7721 as well as their respective precursors) and one thing I notice in general about many beginners is: 1) Most are used to naturally holding larger things (duh! LOL!). It looks really easy when videos of some other notable "microsolders" perform the job really quickly and with precision. If one is really new, then it helps to allow their body to "relax." I totally understand that it's really frustrating at first, but being relaxed is what I truly believe and experienced is paramount. 2) Most just want to get it done. Of course who want's to drag things on, especially since time is money and content viewers most often agree. It helps to also start slow and increase as one develops better manual dexterity. With that mentioned, there are just WAY too many other variables along with various techniques to account for, so I don't want to delve down that rabbit hole (especially since I have to do that almost everyday at my job). On another note, I mentioned the IPC certs earlier ONLY as a reference point, so before anyone reading rushes to get a cert for soldering purposes, they are EXPENSIVE and often UNNECESSARY unless one is in a specialised production and/or mission critical repair environment. Just thought to clarify that. Keep practicing and keep up the good work.
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That was a bit painful to watch :) Here are my smart-ass comments: When you rework a chip like this, remove all solder and flux after you’ve removed the chip. Then solder on the new chip with the iron and lots of flux, using the drag soldering technique. It will be quicker and you’ll not run into the risk of toasting the chip by heating it for too long. Also, get some tacky flux. Liquid flux does not stay where you need it and is much less useful to transfer heat from the iron to the work. It is easy to write all this as I have some experience, but it took me only a year or two to get quite good at SMD rework, as a hobbyist. Keep up the good work, and thank you for all of your videos!
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I certainly could not stand the pain and commented before the end of the video - it is really amazing just how much heat these parts can take! Thank you for demonstrating that, too! This was a very enjoyable morning already :)
Hey man if you didn't try it would STILL be broken and you leveled up your EXP along the way regardless. I appreciate your willingness to be so candid about things that don't always work out initially.
This was great, thanks for showing mistakes, usually you get tutorials but they don't show these kind of pitfalls people can find while soldering SMD components.
A great way to remove solder from bridged pins *without* solder wick is to first apply flux to the pins (I love Chipquik flux - no clean and thick consistency). Then use wick on the hot soldering iron tip itself to remove as much solder as possible. Then apply the hot and "dry" tip to the pins with the solder bridge. The dry tip will suck away excess solder like magic. Perform the tip drying process again and repeat it on the next bridged pin. What I like about this technique is that it removes just the right amount of solder. Love your videos as always!
Adrian, the only other thing I could suggest, is using some sort of vice or clamp to hold the board, as I noticed the board itself moving several times when you were trying to get ready to solder things. Then, add a Gator clip to put some (minor) pressure down on the center of the chip to hold it, rather than using the tweezers. 3rd hands can be absolutely needed when dealing with these issues...
If there's one thing that working with computers over the last 30+ years has taught me is, check your assumptions. I see people making that mistake all the time and wind up going down the wrong road. So I'm happy to see you using the same techniques of making these negative tests, and advocating for the idea that when something isn't working the way you're expecting, that you need to understand what you're taking for granted, and then test those assumptions to make sure they're true.
Career SMD tech here. You might be interested in using a removal alloy instead of high heat. When I remove large ICs like that I replace the high heat solder with the low melting point solder, and the chip will come off with either a little hot air, or simply with a soldering iron. This will also prevent you from destroying any type of conformal coating, or blowing around other components once wet. I use SMD16NL-ND on Digikey 1 Use soldering braid and flux to remove most of the old solder. 2 Add more flux, and apply removal alloy to all pins. Bridge all of the pins with the alloy. You will also see that the new solder will remain wet for much longer. 3 Remove chip, and remove all of the allow from the pads. 4 Add new chip in whatever way you prefer.
I totally agree with everyone who said remove the old solder first and hand solder the new part, good magnification is a must. The RGB2HDMI project is great, replaced the CRT in my Wayne Kerr precision LCR meter with a RGB2HDMI and a small VGA screen. I want to have a few RBG2HDMI units in the lab but the Raspberry PI Zero is really hard to get at the moment.
@@peteroneill404 Yes, I do have several WK 3245B, 6425, 6430 and PMA3260A at my work. Good equipments. I did several repairs at these, and still works after +25 years.
@@alexmirica I bought my 6425 at a local auction for $AU400, 20 years ago. It always had an intermittent unobtaium flyback transformer, which finally failed a few years back. Replacing the CRT with a small VGA screen and the rgbtohdmi has been a good fix. The rgbtohdmi allows a lot of on-screen adjustment, making it easy to align the screen text to the fixed menu separation lines on the front panel.
Hi, good attempt for a beginner in SMD soldering. Tips: Use the desoldering braid to remove the old tin. Then clean it with isopropyl alcohol. After that put some fresh solder on contacts and with a good flux, the chip automagically align itself using the heat machine. At last, clean it again with alcohol.
For what it's worth, I had the same struggles a few months ago with SMD soldering -- except it was only for five pins on a micro-USB connector! The best tools that helped were fine-point and blade-shaped soldering iron tips, the latter of which I used for drag-soldering. I used a gel-like flux that liquified after heating, so it stuck to the pins and didn't find its way across the PCB. But wow -- that microscope makes all the difference!
Dear Adrian Eric (Termineric) here this how I do SMD repair - Remove part - Remove Tin & Flux (Desoldeerstation and IPA) - Put new part on place soldering Diagonal Opposite 2 pins first - Put new flux on it before - Put tin soldering iron only touch only with BLOB so hover just above the pins - Remove Bride solder wick This always work for me
Another great video, Adrian! Very generous of you to share your SMD rework learning experiences. It gets easier the more that you do it. Several other people have already given some great advice. I'd like to emphasize a few things that have worked for me. 1) Always wick off the old solder before placing the new component. Mixing different types of solder will sometimes cause alloys that don't melt or flow well. 2) If you plan to use hot air to solder down the new component, I recommend using solder paste. 3) If you don't have a stencil, hand-soldering these SMD components is often easier -- and I think you realized this pretty quickly. 4) Real Amtech tacky flux is great (and you can get it from Louis Rossmann's store). 5) Using copper braid to remove bridges usually works well, but as you noticed, it will often remove too much solder. Often I can get away with stripping solder from my iron using a brass tip cleaner and then use the iron to wick away the bridge. Works better if you have sufficient flux.
I think you did OK for a first serious attempt. Using a good gel flux is going to make the job a lot easier. It helps stick the components in place before soldering and it doesn't boil off the way liquid fluxes do and cause chips to start floating away.
I really like this one. You say it's not a tutorial in any way, but in my opinion your trial and error is THE tutorial. It's simply what probably happens to any beginner and that you can still get to it by not giving up and trying something else. Also, I don't think the result looks any uglier than what the board looked like at the very beginning. I want to see more like this!
Even with the bridge you found, the work you did looked better than the original work. Louis Rossmann does excellent work with smaller parts and is very good at describing how, why, and what he is doing.
When removing any SMD, mask off with Tape Kapton etc, Heat up then remove, you could heat up a mains cable copper wire in a square with a iron to spread the heat, too long time to do that be aware heat damage PCB, Remove ALL solder, with IC taped into position tac down two or more pins on the IC, then with a fine tip soldering iron with thin solder tac down whilst making sure all pins are flat to the PCB, Always solder from tip of IC Pin to PCB using minimal solder, Clean flux off with isopropyl, use paper towel tap gently around the area of flux, Make sure no flux under components, blow air under components, Dry hottest 50°C Philip retired UKAS - Aerospace Engineer
Man, you are courageous! You have only one spare part, no experience with the method, new tools and you start right at the job. SMD rework will become a part of my job in near future. I watched several YT channels for quite a while to see how pro"s are doing this ( I recommend Northridge Fix) . Then I got some equipment and "training pcb's" from the goodie pile. Worked with that for a while to see what's going for me. Anyway, the result is what counts and that was good. Applause👍😁
Such a brilliant video Adrian, very brave to try something like this for the first time on UA-cam, so massive hats off! I've done 2 of these boards with different methods (stencil-paste-pan-of-sand & fine tip hand drag solder pin by pin) so it's great to see you experimenting too
I honestly love it when you have difficulty with things because it gives me confidence to try something new. I don't feel bad if I start to screw up because I know I'm not alone and I know if I stick with it I will prevail like you do. Thanks for the great video content.
Adrian, you did ok. You had a go, made a few mistakes but completed the job. Well done! The next SMD repair will be a little easier because of those mistakes - that's how we learn.
Jumping On the Bandwagon: I always remove all old solder from SMD/SMT pads, I find it causes me more headaches than it saves me time. You had a nice clean pull (the removal of the chip from the board) and you just had a tough time trying to keep that old solder on there. Glad it worked out in the end!
I've been doing surface mount for years. There is definitely a learning curve to it. If you are going to hand solder, definitely remove all the old solder and just tack down one or two corners. Flux is your friend, I use a Flux pen from chemtronics. Also for removing Flux, I prefer acetone to isopropyl, but it is not safe for all plastics (but will totally dissolve the hard to remove fluxes). Anyway, the end result speaks for itself, great job for a newbie, and the commentary was hilarious.
One tip my boss taught me when showing me how to do SMD work: Cut the solder wick diagonally to have a really precise tip on the wick with low thermal capacity to suck up the excess solder! I recommend ChipQuik for really good flux. Cleans perfectly with IPA. Good luck! Do try again!
I'm sure many others probably mentioned that they we would have removed the old/new solder, cleaned the board, applied new solder, tack a corner down and then as you said drag solder the rest. Rosin flux sucks for doing this kind of work. Thanks for sharing your adventure, everything is hard until you figure out how to do it! ;-)
Adrian, you are one of the best computer guys I have ever seen. Your soldering skills leave a lot to be desired. Tronicsfix here on UA-cam does a very good job of soldering this tiny stuff, I would be surprised if you don't already watch him. Keep on keeping one dude, love the videos.
Thank you for helping me feel better about my own terrible SMD soldering jobs, I can see I'm not the only one out there that has a rough time with it. :)
If that was your first attempt, then you did just fine!. Its a learning curve but after a few goes you get a feel for it. Its amazing just how much chips can tolerate high temperature for such a period of time. The trick to not damaging the device is to keep all the pins and body at the same temperature.Thats why hot air is good. But if you get a gradient, cold one side / hot the other, it can break. But its still best to try and do the job quickly to reduce prolonged heat. Only other tip is: use plenty of flux!. Even old solder will work fine if you have enough on the board and use lots of flux. Great stuff and well done with the result!.
It looks like you had a heck of a learning experience with that chip! It's just that soldering using hot air really requires the use of solder paste instead of solder wire. It's also a good idea to clean the existing solder off the pads prior to attempting to solder the replacement part, really only to make it ALOT easier to place the new chip. All in all, great video! I appreciate your sharing of these "How Not To..." videos.
Seen dave at eevblog do smd soldering a few times, and I think he even did a dedicated video on it a few years ago. After removing old solder and tacking the chip, I think he used a chisel tip and just dragged across several pins at once, came out perfect. Bridge a couple pins, no biggie, clean your tip off and drag it back over the pins. Anyway ya did great and cool video! cheers
As someone experienced with SMD rework, you were so close on your first attempt... Your mistakes were: 1. Don't hold the IC. Ever. It'll move and wiggle (as you said) to find the right location. 2. You needed flux when you put the new part on (to clean the chip pins). You didn't really need flux to remove the old one. Finally when using the iron, you want the tip dry (no solder at all, just heat). And again, more flux! You can never have too much flux! Well done!
There's no harm in including any errors you make, that makes the video better for all of us. We can laugh, but we can also learn that getting things clean before starting is the way to do this SMD soldering. I'm sticking with through hole until you get better.
Interesting video for all of us who grew up in the analog world of through hole components. But one thing that I think would help is to secure the board. You could make some sort of heavy base that won't move around and just mount a stand off on it. Then you could mount the board on the standoff with a nut. This would keep the pcb from moving around.
Hey Adrian !! What about to add this small rgb2hdmi modules (and many other stuff you may have) ready to use in your store ?? I have a MSX with RGB and love to see it in my big screen… Here is very hard to get another kind of technology cause is very, very expensive to import the parts to assembly… the most tine is most easy to buy the circuito ready to use…
Everyone starts somewhere, you did good, it being one of your first tries and all. There is lots of great advice in the comments so I won't repeat, but I will say keep up the great work! :)
One trick i've done with those QFP's is to pre-tin the feet of the IC and then the board, and then with a dry iron tip touch each leg. Avoids a lot of the bridging that happens if you try to drag solder, and there's not much if any excess to clean afterwards. One of the bigger dangers of hot air to attach the IC is that too much heat will cause the pads on the board to start lifting. I'd suggest getting a junk board and heating it up beyond repair to see what happens, after it gets too hot you'll hear it "popcorn". This is where the surface layer starts to come away from the PCB. Interesting stuff. I only use hot air for removal and only if I absolutely have to for attaching BGA components. I'm not that great at it either. Tough skill to master. Northbridge Fix seems to use a coffee filter with ipa to soak up the residue and agitate with a brush. Seems to be very effective without leaving little fibers behind.
I was afraid of SMD soldering for a very long time. I rather drilled a hundred holes into a PCB and use through hole parts even if the same thing could be accomplished with SMD components. That changed in 2018, when my back then boss saw one of my hobby projects being designed and asked me why I'm still using THT stuff. He offered me to have the board made on the company's costs, but only if I used SMD components on it, where possible. Of course, I did agree and when the PCBs came in, he sat down with me, soldered on an IC, while explaining what to do and why, and then handed the rest over to me. He also got me hooked on using desoldering braid, which I now absolutely prefer to solder suckers.
You did a great job on that. I had to replace a 40 pin SMD chip last year, it was 3 hours of pure hell. By the time I finished, I had a wonky chip but a working board. At least your chip was square onto the pads. LOL.
Glad I'm not the only one struggling with that! But learning on the way! My method is to remove the solder from the pads altogether, then go with the soldering iron one leg first, then align, then one leg on the opposite corner. If you leave solder on the pads, the chip is going to sit on the solder and you'll have to add more - potentially - to try and bridge the parts. My opinion anyways. :) Thanks for the video!
Adrian, I ended up buying an smd soldering practice board to improve my smd soldering technique. The practice really helped. If you don’t want to buy a practice board, you could always practice using scrap/parts boards. I like yourself do not do smd soldering as part of my daily work but decided to learn the technique because in the near future everything is going to be smd components and I’d still like to be able to repair those future devices.
I can only echo what others have said, the most important thing for me when assembling these boards is the best quality flux you can get and plenty of it to float the CPLD into position. I use and recommend Amtec 559, a good hot air station is a must, and in the case of my old eyes a magnifying headset and jewellers loop for checking. Then it's just practise, practise and more importantly practise.
the small nozzle is good for a capacitor (small components), to remove an ic, use the bigger one or no nozzle (better heat distribution) you can add new tin to the pads with a soldering iron and speed up the process (it melts faster) The rest is practice.
?????? Contex Drag solder not work to remove ic (unless you use low melt solder and is expensive) Drag solder not work whit rosin or liquid flux, if you have some amtech (995 if I remember) or the Chinese kimbo (work very good) or other of this paste flux (in market are a bunch of this and some work good) . So if you have some paste flux yes use drag solder, I do not take to much time and is easy.
Yeah the nozzle was a bit small for that case. The pros use big nozzle and 450ºC to get it off as quick as possible so they don't delaminate PCBs. Iron/drag solder is easier for the inexperienced because you can control the heat better.
I replace chips like this almost daily in my job. Use a bigger tip on the hot air, temp about 350 and air velocity is set at half power. Then solder new chip not with air but just a soldering iron and drag soldering, with flux all you will need is a little bit of braid cleanup.
Couple people mentioned it but the thing that messed you up on positioning was not cleaning the pads after you pulled the old chip. Wick all that solder off, clean the flux away with alcohol, then apply a TINY amount of flux to the pads, apply heat to the board and flow a VERY small amount of fresh solder so they pads stay flat and don't blob up. Then the chip will want to center its self and the board will be pre-heated. Reflux a small amount on the pins and apply heat. The chip will suck right into position. Remove heat and inspect with a microscope.
like many others have said remove with the hot air, clean the pads and tack the corners. The best flux to use is Amtec bga rework flux it. It just takes time and practice to get better so I say you did a great job for a first time, the fact that it worked is the main thing. 😁
Been there with some of my attempts with SMD soldering. I'm impressed just how resilient the chips are. I always have worried that even just a little extra heat would do them in. Glad you were successful in the end!
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Thank you very much Adrian for another great video! About the 5V tolerant inputs, I've seen some people adding something like a 1k series resistor to those inputs, so it will help "burning" the voltage difference and reduce the risks of damaging the IC.
I just started with SMD soldering with some practice kits I bought on Amazon and I've learned with the solder bridges, if you put a glob of flux on there (I use the thick stuff) and completely clean off the soldering iron tip, you can drag it across and the excess solder will collect on the iron. Sometimes have to clean the tip and go back over it a couple of times if there's a lot, but if it's too much I use the solder braid and redo the pin if too much comes off. .
Don't use wick to clean up shorts between pins. Clean your iron, add flux, and make another pass with the iron, and the iron will wick up the extra solder without desoldering the pins. If it doesn't clear it up, repeat: clean tip, more flux, make another pass. You'll have a much easier time with it that way. Also many people said that, but cleaning up the pads after desoldering the old chip is always a good idea. You'll have an easier time aligning the chip, and you're not mixing solder chemistries.
This brings back bad memories of assembling boards with 0.5mm ribbon cable connectors. The pins kept bridging under the connector, and even after checking them repeatedly with a meter and finding no shorts, they still shorted and burned.
This reminds of my first few attempts to stick chips on the boards. The scare of getting solder bridges especially on low pitch QPFs makes you think pre-tinning pads is a good idea; but good solder joints requires getting both pin and pads hot and as flush as possible; using enough solder, not too much, and a quality flux makes drag soldering easy and only viable option when using soldering iron. Soldering requires a delicate thermal and mechanical conditions and you only learn it by doing it and learning from your mistakes and physical reasons behind those mistakes.
Hey Good job learning! You can only learn by doing! I think your biggest tripping point was the super tiny hot air nozzle. you have to heat the whole chip area at the same time so a bigger nozzle would have helped alot! But yea I think the proper way would have been to after removing the old chip use the braid to wick the solder pads clean. Then tack the corners and then solder the sides that werent tacked and then solder the sides that were tacked. Love your videos! You are such a character!
this is soooo relatable.. should be titled... : "How everyones first 20 attempts at soldering/reflowing SMD parts ( even with capable tools)" you are not alone.. and NO it is NOT "as easy as". Those who says that you know has never done it before.
I've only done one SMD chip before, but what I did was line up the chip and put an alligator clip to hold it in place (which was a tip in the instructions I was following). I think doing the same might have saved you a lot of fiddling with the movement. I too have a cheap hot-air station, but I ignored using it. I just soldered the side away from the clip with my overly-large iron, removed the alligator clip, and then soldered the other side. At the end I had two pins bridged, but just wiped them with a clean tip and it wicked away the right amount of solder - which I consider pretty lucky given my lack of experience/skill soldering.
God, Adrian, you're obviously the quite type! I would have thrown the pcb through the window 3 times... Maybe that's why I don’t often solder smd! Thanks for sharing 👍
LOL! This was so painful to watch, but you did a good job. The hot air rework station is good for REMOVING surface mount components. I'd have removed all the old solder after removing the old chip (making the surface flat), put the new chip on, tack it in place, then just solder the pins with the SMD hoof (or a J tip). I've been using Kester 951 no clean flux which has worked okay, and recently encountered some sticky flux on a board I was removing components from, and it behaved exactly as I though it would, so I'm probably going to switch the type of flux I use when I run out (I also have an MG Chem flux pen).
Another cool and informative video. The capture solution fail was funny. I hate when I do a project like this and end up thinking I missed something because of such silly things. A note on the capture device, I use an evga xr1 lite on my test bench. It has a passthrough HDMI port which comes in handy if I'm building an adapter for display and I get a result like yours. Also I find the proper soldering iron tip with some decent flux and solder is way faster than air and less likely to heat these smds to failure. The iron only passes over a region of the IC at any given time as opposed to heating the whole package with air. That looks like the same scope as I use lol. Earned a sub👍
For smaller chips I find picking a nozzle that's about the size of the chip and blowing straight down on it (with some motion to make sure I hit the pins) does a good job. For example, on a QFP I'd pick a square nozzle that's slightly larger. For a long package like a SOIC I use a round nozzle with a diameter about the width of the chip plus leads. I'd usually rather overheat the chip than the board--the chip usually tolerates it better and the epoxy casing doesn't seem to absorb heat as easily as some PCB surfaces. For larger QFPs (like the ASICs in Sega consoles) it might be worth it to invest in some specialized QFP nozzles. Also, pretty much all hot-air desoldering is made easier with board preheating. The hotter the overall temperature of the board, the less heat will get drawn away from the area you're working on. Heating the whole board slowly and evenly also makes it less likely you will warp or otherwise thermally stress it. I think you can heat most circuit boards to 100 Celsius without damage--just beware that you don't use a preheating method that can cause hot spots or overshoot your target temperature (like infrared).
Oh yes... soldering SMD is a nightmare. But your mishap gave me a good chuckle cause I couldn't help to think that you gave new meaning to the "+/- 1 error" that is common in programming 😉 - I think the "let the solder pull the chip" trick works regardless of the chip size, because: larger chip, more pins. It should be proportional force to help pull the chip into position, but whenever you push down on the chip it's slipping away.
Not that my experience matters but, I recommend removing old solder and then using solder paste with the hot air. The chip and other small parts don't move with it.
@@yoyomismo2052 I don't have any problems with it. I use a syringe and clean up with Alcohol afterwards. We all find our own way; with my shaky hands, it works best for me.
Solder paste is too much of a pain without proper stencils... and it's usually too thick to apply manually.. though you can mix it with a bit of alcohol or thinner flux to make it a bit more runny. You'll end up wicking most of the excess away though, or worse - getting unmelted paste stuck under the chip!
Can't say I'd recommend this method for repairs over just tinning the pads + hot air, although for a leaded device like this, I would use hot air with a much wider nozzle or ChipQuik alloy to remove, clean the pads, then place the device by hand either pin-by-pin for this 0.8mm device, or drag soldering + wick for smaller pitch devices. Even if you happened to have a stencil available for the device's pads, it's very unlikely to fit on an otherwise already populated board.
I agree with tommy, solder paste is alot easier, a good paste wont create much mess, also the smd parts will move in place easily without much fuss. You can then use a small soldering iron tip to cleanup if need be with some flux.
Adrian I think you did very well if this was one of your first times. I've been doing SMD repairs for a few years, and I would just give you a couple tips - Use a good quality tacky flux (MG Chemicals, Amtech, etc), It will actually help keep the component in place, it wont get boiled off so quickly, and if you use enough flux the surface tension and heat will often line up the chip perfectly for you. When you remove the chip, clean the original solder off the pads and apply new solder, it's just good practice. Also, if you eventually end up doing more SMD work, I would invest in a decent hot air station. Those cheap $40-$80 units with random names on them that are all over Amazon, Ebay, etc. do not have nearly as good thermal capacity as something like a name brand Quick 857DW+ that only costs a few dollars more. Also those cheap hot air stations scare me. There are way too many videos and personal experiences from people who have had them randomly melt down and catch fire right there on the bench. I always recommend that if people have to buy those things, definitely take it apart and inspect it. About half the time the mains input is accidentally wired backwards into the power switch and board and the station will still work like this but it is an absolute safety hazard. The quality control on those things is abysmal.
I have one of those burned up fcks here and indeed they start melting random...
tbh I find it easier to completley remove the solder and place the chip, then use a regular soldering iron instead of using hot air to put it back on.
I admire Adrian's honesty by putting this online! I have a few constructive tips to add..
The desoldering nozzle was too small. The nozzle needs to be about the same size as the device that's being lifted, rather than struggling by dancing around the chip, and risk pulling a pad or a trace as you tug on the device. (For multilayer and/or large boards, the thermal mass is much higher so will take a while to start melting the solder: some use a board preheater, but for a board of this size there's no need).
Another trick in removal is to tin the leads & pads with leaded solder while the part's still on the board to bring the melting temp down, or, even easier, use low temp repair solder like ChipQuik alloy.
The same comment about nozzle size applies to placing too when using reflow: it needs to have simultaneous heat coverage over the entire device. Dancing around the chip with a small nozzle is going to end up... well, we saw how it ends up!
For placing leaded parts like this, I use drag soldering for small pitches under 0.8mm, but the part here has a pitch large enough that they could reasonably easily be hand soldered.
Anchor the part with a couple of diametrically opposite pins before drag or pin-by-pin soldering.
With drag soldering, you have to accept that however hard you try you'll end up bridging pins at some stage.
If you're going to hand solder by dragging or pin by pin rather than reflow, then you really should to clean the pads first.
I keep two thicknesses of wick available, and two thicknesses of solder on the bench.
I don't know what the purpose was of adding solder directly to the tip of the iron. The pads can be re-tinned applying small amounts of solder to the pads as necessary as the iron traverses the pre-fluxed pads.
I use a stereo optical zoom microscope, the digital microscopes add latency and lack spatial dimension.
One further trick about checking pin continuity when the board is otherwise empty, for example with breakout boards: as well as adjacent pin short check, you can usually also check for pin connectivity to the board by using a DMM with an audible diode check; hold the + probe on a ground pin, and buzz out the other pins, using the protection diodes.
Yeah, I really think Adrian's problems were that he didn't clean the board and put the chip down directly on the pads, THEN add solder to a couple of pins to tack it down and go from there. What I know about SMD soldering is that it's always about mess control. You make one when/where you need to, and clean it up any time you have the opportunity. You use a lot of flux, a lot of solder wick, and a little more solder … but it's a lot less flustration that way.
you cannot "wire it backwards", main power (mostly) is a 2 prong plug that you can plug in any way you want in Europe. I do not think, even if you are in other countries, that power will work differently there ;)
After removing the old IC you also have to remove the old tin with the stranded wire. Then the IC lies flat.
Solder two corners with a little tin with the soldering iron, it doesn't have to be pretty, the IC just has to be straight. Then use a soldering iron to solder the pins with a lot of flux and a moderate amount of tin.
If a bridge appears, ignore it, strip the soldering iron and use fresh tin moderately.
Always give the IC some time to cool down and don't constantly re-solder yourself in one place and over heat.
Allow to cool, breathe deeply, or take a break and try again if it's cold again.
I can't solder much better, but you'll get practice with time.
Good job Adrian
I've been working with SMD and BGA soldering for a living for 11 years now, and I think that the easiest way to solder QFPs like this is to NOT remove old solder from the board, but this works only if you use paste flux and if your IC pins aren't oxidized. Most paste fluxes will work but you'll save yourself from headdaches if you'll use good flux (I can recommend FluxPlus 6-411-A or 6-412-A, one of the best fluxes that I used). The process goes like this:
1) Apply some flux on the pins of the IC you want to desolder. You don't need to use much, but at this point it is not important, you can add as much as you like, just make sure that the flux covers all the pins (I mean the bottom part of the pins which is soldered to PCB, not the whole pin) and space between pins.
2) On you hot air fan use a noozle that is near the size or a little bigger than the IC you want to desolder. This will guarantee that when solder will start to melt all of the pins will stay melted and not become solid again. To not overheat the IC don't hold the hot air fan in one place, move it around in cilrcular motion, but not too quick or it will take much more time to heat the solder.
3) When the solder on all the pins have melted remove the IC from the board by grabbing it with fine tweezers from the corner with one half of the tweezers put under and one on top of the IC. Be careful to not move the IC around the board. After you remove the IC this way the solder on the pads on the PCB will be distributed evenly and the shape of the blobs will be close to identical.
4) Let the board cool down. After it's cooled remove flux residue using some kind of solvent (I use Electro Degreaser by Cramolin, my colleagues just use acetone), you can use isopropyl alcohol but solvent does much better. Wipe it using a piece of thin cloth soaked in solvent or use a toothbrush. Remove excessive solvent using a dry piece of cloth. When your board is cleaned add fresh flux on all the pads. This time don't use to much flux, because when it'll boil it can move the IC around. Once again, add enough so it'll cover all the pads when melted.
5) Carefully position your IC on top of the solder blobs that are left on the solder pads. This is not an easy process and somewhat tedious. your positioning don't need to be 100% accurate, just make sure that pins are not laying between pads, they need to be on top of the solder blobs.
6) Don't hold the IC in place, just heat it using hot air fan but be sure to hold it the fan perpendicularly to the board and don't use too much airflow to not blow the ic off its position. Again, use circular motions. When the solder will melt your IC will, firstly, tin itself and, secondly, position itself on the solder pads. After this is done cool off the board and clean it using solvent and a toothbrush.
7) Check that all the pins are properly soldered using a needle or fine tweezer - just lightly drag the needle on top of the soldered parts of the pins, if any pin isn't properly soldered it'll bend a little which'll be immediatly noticeable. If there'll be some unsoldered pins then you can solder them using a little flux and a soldering iron. Don't add new solder if there's enough old solder on the pad, this is to ensure that you don't short adjacent pins.
Most of the time this technique gives near factory level soldering quality, but you need some practice to get it right.
Wow, no need for a story. He did very well for a new solderer.
FWVLIW: Everyone struggles with SMD soldering when moving from through-hole. Much of the struggle is a matter of mindset.
Through-hole - You're not so bothered about accurate component placement but you want to be accurate with your soldering.
SMD - You want to be very accurate with your component placement but as long as you use plenty of the right flux you don't care about the accuracy of your soldering - surface tension will take care of it as long as you use it rather than fight it.
Three basic techniques: (Always start with clean pads and use SMD-apocopate flux. For the most part use one technique or the other!)
1) Use a soldering iron to dab / drag your solder for affixing pins. Don't pre-tin!!!
2) Use hot air to melt your part(s) on to their pre-tinned (or preferably solder pasted) pads - a little shimmy will let you know the solder has melted.
3) Use something like a toaster-oven, pre-solder paste pads, pre-place parts, and let nature take it's course.
-Either hold the part in place from the get-go or don't touch it at all! Touching a part you're in the middle of soldering will mess it up!
-There will be solder bridges when soldering multi-pin packages - DO NOT use solder braid!!! Flux and a clean iron tip should be all you need.
-Each to their own but many use a soldering iron for passive components and hot air (if they have it) for ICs with lots of legs
-Option 3) is great if you're doing a lot of SMD soldering, a bit of a faff for single boards or short runs.
Once you have the SMD mindset you'll be golden. Be warned, you'll probably find your through-hole soldering gets messier.
I hope that helps somebody. Do what Adrian's doing and give it a go.
Yeah, I can approve your tip list. I always teach my students to consider first what technique they want to use to solder the part. When you use hot air soldering, there should be the right amount of flux on the board, then it does not matter which flux you take (surely not the one that evaporates quickly). If there is too much flux your ic will swim on the flux and will not make good contact with the solder. If there is the right amount, the flux will prevent shorting the pins and the surface tension will do the rest and DON'T touch the ic, it only misplaces your ic and you have to start again. Using QFP packages and a microscope I rather always use drag soldering, because you don't stress your ic so much and get it in place quickly and the cleaning afterwards is not that an efford.
But Adrian good job for your first time soldering an smd ic. Do a little bit exercising, perhaps on old defect boards (soldering off an smd chip, clean it and solder it back on), then your next production board will be childs play.
What I learned from this video was just as valuable as watching Louis Rossman or NorthridgeFix. I learn more when things go wrong than when they go right. When things start to go outside of what you have learned about then it's easy to panic, and when I try this (and inevitably the same things happen) I will know not to panic, this is not unexpected given inexperience, and I just need to practice more.
The guy at NorthridgeFix makes soldering this stuff look easy. He obviously has a lot of practice at it.
+1 for Louis Rossmann, watching his videos got me into micro-soldering and the RGB2HDMI was my first SMD project. Leaded solder, decent amount of flux, a fine hot air nozzle and a microscope makes the job a cinch 🙂👍
13:26 Louis Rossmann approves this message
Don't sweat the mistakes. You learned, and that's why we watch! I was rooting for you the whole time, and you got it done.
I echo others comments in that oftentimes I learn more from when things go wrong, than watching a perfect tutorial. Thank you for posting this video! I've never tried SMD soldering, but now I have an idea of what can happen
exactly - I lerned more from replacing a GPU on a laptop then I did in school replacing components. Also what might be the easy or right way for some may not work for you, while the really hard way may seem easy.... I also found out I was old and needed a lot of magnafication to really see any missed connections and bridges -
Adrian, as a newbie enthusiast it’s wonderful to see someone so skilled have and share their learning opportunities! The honesty is refreshing and helps remind me and hopefully others we all have opportunities to grow and learn new skills.
As others have mentioned, the way I have succeeded in replacing QFP chips is to use hot air to remove it (including using aluminum tape to sheild surronding devices), clean off all the old flux and solder, put on some no clean flux, use a soldering iron to tack the corners and then all the other pins. remove bridges with solder braid. You ended up with the chip sittong on bumps of solder, which means its not flat to the pcb, which is why bridging was a issue. That said, the finished job was neat enough. Maybe get some broken cards and practice some!
You never claim to be an expert at anything and often make a point of saying you're not, but I continue to learn a huge amount from you. It's kind of refreshing to see you having difficulty with something I would usually be okay with, again really appreciate the humility in sharing your mistakes.
As others have said, after the package was clear of the board I would have taken the old solder from the pads with wick and then cleaned with IPA, then approached it like a new board i.e. two corners first and then drag-solder the rest. I would only use hot air to solder components *in* if working with solder paste. Another trick I found was to use a sticky flux on the pads, carefully place the chip and then leave it to dry, then drag-solder the whole thing. This resulting in better alignment with the pads without bending any of the leads, making the drag soldering stage fairly easy and these were QFP-144 ICs with 0.5 mm pitch.
Great to see you got it working though, all's well that ends well.
Thank you for making a video showing that even an inexperienced amateur with cheap no-brand equipment, can get somehing working! It is nice to see someone else trying and learning a new skill - and the comments are filling up with good advice and suggestions for everyone trying to learn! Nice!
Adrian, you did fine here, when I did this kind of work I always used air to remove and the iron to replace. I'd remove, clean up all pads so they're absolutely dry (no solder), flux, then do exactly what you did by tacking opposite corners, then I'd tack the remaining corners if I was 100% happy with the alignment, then I'd just solder all the legs with the iron. If you have something that can evenly heat the board slowly the chip would (usually!) align itself without doing it manually but I've also seen them turn and align crooked. For chips like this, especially for a hobbyist, air to remove, iron to replace :)
one thing I found really useful when I was learning to SMD solder is that there are some $10 all-SMD kits available from various little shenzhen brands which contain the parts for a 555-based blinking light circuit, and a bunch of extra SMD chip resistors/capacitors just for practice. I bought a couple of those and the first one was a write-off, but the second one helped me get my techniques down and even gave me a little experience troubleshooting! loved the video and looking forward to more from you soon.
I taught myself on junk consumer electronics in the early '90s. It was on thin, cheap phenolic circuit boards which was easy to burn.
Yeah, I got myself one of these that had passives down to 0402, some cylindrical components (they were the hardest), and some LEDs and transistors. It was a really good training exercise. The one I got had resistors down one side in series, and caps down the other side in parallel, with a couple of test points either end so you could put your multimeter on it and check the components summed to the correct values.
@@merseyviking Those round components are called 'Metal Electrode Leadless Face' (MELF). You need either two irons or soldering tweezers to do them properly. They were intended for automated assembly, with solder paste.
Thanks! I'm going to look up those kits. Currently working on my first SMD microcontroller PCB and want to avoid destroying it with shotty soldering.
It's so honest of you to admit your shortcomings and share your learning experiences, even when your successes are so close to failure! I think this actually helped me. I've not done very well with SMD soldering myself and it's humbling to know that someone so experienced in working on PCBs in general can have the same problems as I. Moreover, the fact that you kept trying and made it through will be encouraging to many. Thanks for the inspiration!
This was absolutely a tutorial no matter what you said! I love how you've shown how wrong things can go if you've never done this sort of thing before. That you're comfortable showing your viewers you're not doing things perfectly the first time speak volumes - I really think seeing what not to do can be as educational as a 'proper' tutorial. Thanks dude.
Hey Adrian don't be too hard on yourself you did really well for your first time, my only suggestion would be use a bigger nozzle for a chip that size and a little more heat 380c,
set the chip down and apply heat.
once its flowing nudge it inplace,
only hold down then for cooling.
hope this helps.
Adrian. As a professional smd technician with 30ish years experience, it was 'entertaining' to watch. I love that you get in and have a go. I enjoy the channel alot.
Adrian, I appreciate your honest content. Remember, SMD stands for Soldering Made Difficult.
You couldn't have titled this video better 🙂
You are very lucky that the CPLD survived this torture (your words, not mine, but I strongly agree.)
Here are some pointers for the next time:
1) Always clean the pads of any solder and old flux COMPLETELY after removing an IC. DO NOT pre-fill the pads with new solder, they have to be absolutely flat (like a new PCB) to be able to seat the new IC properly and easily.
2) Before you seat the new IC, apply a a little paste flux on to the clean pads, DO NOT use liquid flux because it is like 95% alcohol and it will evaporate as soon as you apply any heat. The flux you put here will also act like a weak adhesive and will help to keep the IC in place later on.
3) Seat the new IC and make sure all the pins on all the sides are aligned perfectly, press the IC down firmly enough to keep it in place and apply a TON of paste flux on the pins. I can't stress the term "a ton of flux" more here, really put a stupid amount of it. See Louis Rossman's videos for the amount. 🙂
4) Take a chiseled tip iron, clean the tip well. Just add a tiny, tiny, tiny bit of solder on to the tip on the iron and tack down just one pin. You will be doing this with one hand with the other one still pressing down on the IC, so pick the easiest pin on one of the corners. Check that it took solder and it is soldered down. It doesn't matter if it is bridged or not soldered pretty, it is just an anchor for the time being.
5) Make sure the IC is still aligned, and do another pin on the opposite side, still pressing the IC down.
6) Now that your IC is properly held in place by 2 sides, you can do the rest of the pins, just add more flux paste to the areas it is melted away, clean the iron tip, and add a small amount of solder on it. How much is "small"? I hear you asking, well, exactly half of what you think it is.
7) Drag solder the pins on one side that isn't tacked down. Make sure you are touching just the tips (ends) of the pins, which means the tips that are touching the PCB. DO NOT touch the whole pin, that's how you get bridges. Touching just the pin ends is very important. It ensures less friction, less heat transfer to the IC body, better solder flow on to the PCB and under the pin. Now clean the iron tip again, put new solder on (now that you've discovered you actually put more than needed the first time, put less) , and do the opposite side, followed by the sides that you already have one pin tacked, cleaning the iron well and applying new solder before each side.
8) Clean the board with IPA of all the flux and check your work under magnification. If any pin looks suspicious to you, just apply flux (a ton) to the whole side and pass over all the pins on that side with a clean iron tip, no solder, again touching just the pin ends. This will re-do all pins on that side and distribute the solder that is already in evenly, taking care of small bridges. Clean the board again, check again until you like what you see.
Not easy to install, but you own the right tools, so that is a good start. Always tape down the board with Kapton tape when installing the chip. Not doing this caused you a lot of pain.Use hot air to remove leaded SMD components. Take out all the solder with iron, solder braid and flux before installing the new chip. Use soldering iron with a small bevelled tip. Use very little solder (you added too much) and a lot of flux. Sweep on the pin tips and pads, not over the pins. otherwise you risk creating bridges on the slanted parts of the pins. Good luck!
You leaned, you laughed, you produced worthwhile content! This makes me feel better about my own skills seeing someone so proficient in so much struggling like I do.
Thank you for uploading this, it’s reassuring to see some reality for a change, which makes me feel better about my efforts! It can be quite demoralising watching an expert make something look very easy, then find yourself making a huge mess instead!
Kudos to you for your perseverance and sense of humor. I don't know the proper way to resolder a SMD device with multiple pins. The problem with using the "corner tack" method, like you did, is that the pins are being held up off the pads by the old solder.
If I may be captain obvious by adding like the 1 millionth likewise comment here... you were quite good, especially since you got the job done. Believe it or not, I've been performing SMT soldering for over 33 years as well as holding various IPC CIS and CIT certs (J-STD-001, A-610, 7711/7721 as well as their respective precursors) and one thing I notice in general about many beginners is:
1) Most are used to naturally holding larger things (duh! LOL!). It looks really easy when videos of some other notable "microsolders" perform the job really quickly and with precision. If one is really new, then it helps to allow their body to "relax." I totally understand that it's really frustrating at first, but being relaxed is what I truly believe and experienced is paramount.
2) Most just want to get it done. Of course who want's to drag things on, especially since time is money and content viewers most often agree. It helps to also start slow and increase as one develops better manual dexterity.
With that mentioned, there are just WAY too many other variables along with various techniques to account for, so I don't want to delve down that rabbit hole (especially since I have to do that almost everyday at my job). On another note, I mentioned the IPC certs earlier ONLY as a reference point, so before anyone reading rushes to get a cert for soldering purposes, they are EXPENSIVE and often UNNECESSARY unless one is in a specialised production and/or mission critical repair environment. Just thought to clarify that.
Keep practicing and keep up the good work.
That was a bit painful to watch :) Here are my smart-ass comments: When you rework a chip like this, remove all solder and flux after you’ve removed the chip. Then solder on the new chip with the iron and lots of flux, using the drag soldering technique. It will be quicker and you’ll not run into the risk of toasting the chip by heating it for too long. Also, get some tacky flux. Liquid flux does not stay where you need it and is much less useful to transfer heat from the iron to the work. It is easy to write all this as I have some experience, but it took me only a year or two to get quite good at SMD rework, as a hobbyist. Keep up the good work, and thank you for all of your videos!
I certainly could not stand the pain and commented before the end of the video - it is really amazing just how much heat these parts can take! Thank you for demonstrating that, too! This was a very enjoyable morning already :)
Hey man if you didn't try it would STILL be broken and you leveled up your EXP along the way regardless. I appreciate your willingness to be so candid about things that don't always work out initially.
This was great, thanks for showing mistakes, usually you get tutorials but they don't show these kind of pitfalls people can find while soldering SMD components.
A great way to remove solder from bridged pins *without* solder wick is to first apply flux to the pins (I love Chipquik flux - no clean and thick consistency). Then use wick on the hot soldering iron tip itself to remove as much solder as possible.
Then apply the hot and "dry" tip to the pins with the solder bridge. The dry tip will suck away excess solder like magic.
Perform the tip drying process again and repeat it on the next bridged pin. What I like about this technique is that it removes just the right amount of solder. Love your videos as always!
Adrian, the only other thing I could suggest, is using some sort of vice or clamp to hold the board, as I noticed the board itself moving several times when you were trying to get ready to solder things. Then, add a Gator clip to put some (minor) pressure down on the center of the chip to hold it, rather than using the tweezers. 3rd hands can be absolutely needed when dealing with these issues...
If there's one thing that working with computers over the last 30+ years has taught me is, check your assumptions. I see people making that mistake all the time and wind up going down the wrong road.
So I'm happy to see you using the same techniques of making these negative tests, and advocating for the idea that when something isn't working the way you're expecting, that you need to understand what you're taking for granted, and then test those assumptions to make sure they're true.
Career SMD tech here. You might be interested in using a removal alloy instead of high heat.
When I remove large ICs like that I replace the high heat solder with the low melting point solder, and the chip will come off with either a little hot air, or simply with a soldering iron. This will also prevent you from destroying any type of conformal coating, or blowing around other components once wet. I use SMD16NL-ND on Digikey
1 Use soldering braid and flux to remove most of the old solder.
2 Add more flux, and apply removal alloy to all pins. Bridge all of the pins with the alloy. You will also see that the new solder will remain wet for much longer.
3 Remove chip, and remove all of the allow from the pads.
4 Add new chip in whatever way you prefer.
I totally agree with everyone who said remove the old solder first and hand solder the new part, good magnification is a must. The RGB2HDMI project is great, replaced the CRT in my Wayne Kerr precision LCR meter with a RGB2HDMI and a small VGA screen. I want to have a few RBG2HDMI units in the lab but the Raspberry PI Zero is really hard to get at the moment.
WK3245? :)
@@alexmirica No, mine is a WK6425, old but has much better accuracy than I need for most measurements.
@@peteroneill404 Yes, I do have several WK 3245B, 6425, 6430 and PMA3260A at my work. Good equipments. I did several repairs at these, and still works after +25 years.
@@alexmirica I bought my 6425 at a local auction for $AU400, 20 years ago. It always had an intermittent unobtaium flyback transformer, which finally failed a few years back. Replacing the CRT with a small VGA screen and the rgbtohdmi has been a good fix. The rgbtohdmi allows a lot of on-screen adjustment, making it easy to align the screen text to the fixed menu separation lines on the front panel.
Hi, good attempt for a beginner in SMD soldering. Tips: Use the desoldering braid to remove the old tin. Then clean it with isopropyl alcohol. After that put some fresh solder on contacts and with a good flux, the chip automagically align itself using the heat machine. At last, clean it again with alcohol.
For what it's worth, I had the same struggles a few months ago with SMD soldering -- except it was only for five pins on a micro-USB connector! The best tools that helped were fine-point and blade-shaped soldering iron tips, the latter of which I used for drag-soldering. I used a gel-like flux that liquified after heating, so it stuck to the pins and didn't find its way across the PCB. But wow -- that microscope makes all the difference!
Dear Adrian
Eric (Termineric) here this how I do SMD repair
- Remove part
- Remove Tin & Flux (Desoldeerstation and IPA)
- Put new part on place soldering Diagonal Opposite 2 pins first
- Put new flux on it before
- Put tin soldering iron only touch only with BLOB so hover just above the pins
- Remove Bride solder wick
This always work for me
Another great video, Adrian! Very generous of you to share your SMD rework learning experiences. It gets easier the more that you do it. Several other people have already given some great advice. I'd like to emphasize a few things that have worked for me. 1) Always wick off the old solder before placing the new component. Mixing different types of solder will sometimes cause alloys that don't melt or flow well. 2) If you plan to use hot air to solder down the new component, I recommend using solder paste. 3) If you don't have a stencil, hand-soldering these SMD components is often easier -- and I think you realized this pretty quickly. 4) Real Amtech tacky flux is great (and you can get it from Louis Rossmann's store). 5) Using copper braid to remove bridges usually works well, but as you noticed, it will often remove too much solder. Often I can get away with stripping solder from my iron using a brass tip cleaner and then use the iron to wick away the bridge. Works better if you have sufficient flux.
Wow! What a ride, Adrian. Glad it had a happy ending! I think I have a few projects that involve SMD that I have simply abandoned. Oof.
You know this was even more fun that hitting a HR in your first at bat. I would never try to do this! First, I don't have the equipment. Good job!
I think you did OK for a first serious attempt. Using a good gel flux is going to make the job a lot easier. It helps stick the components in place before soldering and it doesn't boil off the way liquid fluxes do and cause chips to start floating away.
Thank you for sharing your mistakes and failures with us along with the projects that go perfectly! I really enjoyed this!
This video made me feel a whole lot better about my surface mount soldering, thanks for the informative and entertaining videos!
I really like this one. You say it's not a tutorial in any way, but in my opinion your trial and error is THE tutorial. It's simply what probably happens to any beginner and that you can still get to it by not giving up and trying something else. Also, I don't think the result looks any uglier than what the board looked like at the very beginning. I want to see more like this!
Even with the bridge you found, the work you did looked better than the original work. Louis Rossmann does excellent work with smaller parts and is very good at describing how, why, and what he is doing.
When removing any SMD, mask off with Tape Kapton etc, Heat up then remove, you could heat up a mains cable copper wire in a square with a iron to spread the heat, too long time to do that be aware heat damage PCB,
Remove ALL solder, with IC taped into position tac down two or more pins on the IC, then with a fine tip soldering iron with thin solder tac down whilst making sure all pins are flat to the PCB,
Always solder from tip of IC Pin to PCB using minimal solder,
Clean flux off with isopropyl, use paper towel tap gently around the area of flux,
Make sure no flux under components, blow air under components, Dry hottest 50°C
Philip retired UKAS - Aerospace Engineer
Man, you are courageous! You have only one spare part, no experience with the method, new tools and you start right at the job. SMD rework will become a part of my job in near future. I watched several YT channels for quite a while to see how pro"s are doing this ( I recommend Northridge Fix) . Then I got some equipment and "training pcb's" from the goodie pile. Worked with that for a while to see what's going for me. Anyway, the result is what counts and that was good. Applause👍😁
Such a brilliant video Adrian, very brave to try something like this for the first time on UA-cam, so massive hats off! I've done 2 of these boards with different methods (stencil-paste-pan-of-sand & fine tip hand drag solder pin by pin) so it's great to see you experimenting too
I honestly love it when you have difficulty with things because it gives me confidence to try something new. I don't feel bad if I start to screw up because I know I'm not alone and I know if I stick with it I will prevail like you do. Thanks for the great video content.
Adrian, you did ok. You had a go, made a few mistakes but completed the job. Well done! The next SMD repair will be a little easier because of those mistakes - that's how we learn.
Jumping On the Bandwagon: I always remove all old solder from SMD/SMT pads, I find it causes me more headaches than it saves me time. You had a nice clean pull (the removal of the chip from the board) and you just had a tough time trying to keep that old solder on there. Glad it worked out in the end!
Bravo for retaining your sense of humor through the whole ordeal.
I've been doing surface mount for years. There is definitely a learning curve to it. If you are going to hand solder, definitely remove all the old solder and just tack down one or two corners. Flux is your friend, I use a Flux pen from chemtronics. Also for removing Flux, I prefer acetone to isopropyl, but it is not safe for all plastics (but will totally dissolve the hard to remove fluxes).
Anyway, the end result speaks for itself, great job for a newbie, and the commentary was hilarious.
One tip my boss taught me when showing me how to do SMD work:
Cut the solder wick diagonally to have a really precise tip on the wick with low thermal capacity to suck up the excess solder!
I recommend ChipQuik for really good flux. Cleans perfectly with IPA.
Good luck! Do try again!
I'm sure many others probably mentioned that they we would have removed the old/new solder, cleaned the board, applied new solder, tack a corner down and then as you said drag solder the rest. Rosin flux sucks for doing this kind of work. Thanks for sharing your adventure, everything is hard until you figure out how to do it! ;-)
Adrian, you are one of the best computer guys I have ever seen. Your soldering skills leave a lot to be desired. Tronicsfix here on UA-cam does a very good job of soldering this tiny stuff, I would be surprised if you don't already watch him. Keep on keeping one dude, love the videos.
I love that you share your journeys with us. Seeing things go wrong, and how you worked through them, gives hope that maybe I can do it too.
Great to see someone else learning and having same issues as myself. Thanks for sharing
Thank you for helping me feel better about my own terrible SMD soldering jobs, I can see I'm not the only one out there that has a rough time with it. :)
I think this has been one of the most enjoyable videos you have made to date!
If that was your first attempt, then you did just fine!. Its a learning curve but after a few goes you get a feel for it. Its amazing just how much chips can tolerate high temperature for such a period of time. The trick to not damaging the device is to keep all the pins and body at the same temperature.Thats why hot air is good. But if you get a gradient, cold one side / hot the other, it can break. But its still best to try and do the job quickly to reduce prolonged heat. Only other tip is: use plenty of flux!. Even old solder will work fine if you have enough on the board and use lots of flux. Great stuff and well done with the result!.
It looks like you had a heck of a learning experience with that chip! It's just that soldering using hot air really requires the use of solder paste instead of solder wire. It's also a good idea to clean the existing solder off the pads prior to attempting to solder the replacement part, really only to make it ALOT easier to place the new chip.
All in all, great video! I appreciate your sharing of these "How Not To..." videos.
Action, suspense, drama, and success at the end! Great work, Adrian. I'd probably burn a hole through the chip...
Seen dave at eevblog do smd soldering a few times, and I think he even did a dedicated video on it a few years ago. After removing old solder and tacking the chip, I think he used a chisel tip and just dragged across several pins at once, came out perfect. Bridge a couple pins, no biggie, clean your tip off and drag it back over the pins. Anyway ya did great and cool video! cheers
As someone experienced with SMD rework, you were so close on your first attempt... Your mistakes were:
1. Don't hold the IC. Ever. It'll move and wiggle (as you said) to find the right location.
2. You needed flux when you put the new part on (to clean the chip pins). You didn't really need flux to remove the old one.
Finally when using the iron, you want the tip dry (no solder at all, just heat).
And again, more flux! You can never have too much flux!
Well done!
There's no harm in including any errors you make, that makes the video better for all of us. We can laugh, but we can also learn that getting things clean before starting is the way to do this SMD soldering. I'm sticking with through hole until you get better.
Interesting video for all of us who grew up in the analog world of through hole components. But one thing that I think would help is to secure the board. You could make some sort of heavy base that won't move around and just mount a stand off on it. Then you could mount the board on the standoff with a nut. This would keep the pcb from moving around.
Adrian, I applaud your efforts to solder that down with hot-air alone. You could learn a lot from watching Voultar solder on older consoles.
Hey Adrian !!
What about to add this small rgb2hdmi modules (and many other stuff you may have) ready to use in your store ??
I have a MSX with RGB and love to see it in my big screen…
Here is very hard to get another kind of technology cause is very, very expensive to import the parts to assembly… the most tine is most easy to buy the circuito ready to use…
Everyone starts somewhere, you did good, it being one of your first tries and all. There is lots of great advice in the comments so I won't repeat, but I will say keep up the great work! :)
One trick i've done with those QFP's is to pre-tin the feet of the IC and then the board, and then with a dry iron tip touch each leg. Avoids a lot of the bridging that happens if you try to drag solder, and there's not much if any excess to clean afterwards.
One of the bigger dangers of hot air to attach the IC is that too much heat will cause the pads on the board to start lifting. I'd suggest getting a junk board and heating it up beyond repair to see what happens, after it gets too hot you'll hear it "popcorn". This is where the surface layer starts to come away from the PCB. Interesting stuff. I only use hot air for removal and only if I absolutely have to for attaching BGA components. I'm not that great at it either. Tough skill to master.
Northbridge Fix seems to use a coffee filter with ipa to soak up the residue and agitate with a brush. Seems to be very effective without leaving little fibers behind.
I was afraid of SMD soldering for a very long time. I rather drilled a hundred holes into a PCB and use through hole parts even if the same thing could be accomplished with SMD components. That changed in 2018, when my back then boss saw one of my hobby projects being designed and asked me why I'm still using THT stuff. He offered me to have the board made on the company's costs, but only if I used SMD components on it, where possible. Of course, I did agree and when the PCBs came in, he sat down with me, soldered on an IC, while explaining what to do and why, and then handed the rest over to me. He also got me hooked on using desoldering braid, which I now absolutely prefer to solder suckers.
You did a great job on that. I had to replace a 40 pin SMD chip last year, it was 3 hours of pure hell. By the time I finished, I had a wonky chip but a working board. At least your chip was square onto the pads. LOL.
Thank you so much for showing all your work. It is invaluable to us who have been hesitant to do any repair like that.
Glad I'm not the only one struggling with that! But learning on the way! My method is to remove the solder from the pads altogether, then go with the soldering iron one leg first, then align, then one leg on the opposite corner. If you leave solder on the pads, the chip is going to sit on the solder and you'll have to add more - potentially - to try and bridge the parts. My opinion anyways. :) Thanks for the video!
Adrian, I ended up buying an smd soldering practice board to improve my smd soldering technique. The practice really helped. If you don’t want to buy a practice board, you could always practice using scrap/parts boards. I like yourself do not do smd soldering as part of my daily work but decided to learn the technique because in the near future everything is going to be smd components and I’d still like to be able to repair those future devices.
I can only echo what others have said, the most important thing for me when assembling these boards is the best quality flux you can get and plenty of it to float the CPLD into position. I use and recommend Amtec 559, a good hot air station is a must, and in the case of my old eyes a magnifying headset and jewellers loop for checking. Then it's just practise, practise and more importantly practise.
the small nozzle is good for a capacitor (small components), to remove an ic, use the bigger one or no nozzle (better heat distribution) you can add new tin to the pads with a soldering iron and speed up the process (it melts faster)
The rest is practice.
no, you drag solder.......
?????? Contex
Drag solder not work to remove ic (unless you use low melt solder and is expensive)
Drag solder not work whit rosin or liquid flux, if you have some amtech (995 if I remember) or the Chinese kimbo (work very good) or other of this paste flux (in market are a bunch of this and some work good) . So if you have some paste flux yes use drag solder, I do not take to much time and is easy.
Yeah the nozzle was a bit small for that case. The pros use big nozzle and 450ºC to get it off as quick as possible so they don't delaminate PCBs. Iron/drag solder is easier for the inexperienced because you can control the heat better.
I replace chips like this almost daily in my job. Use a bigger tip on the hot air, temp about 350 and air velocity is set at half power. Then solder new chip not with air but just a soldering iron and drag soldering, with flux all you will need is a little bit of braid cleanup.
Couple people mentioned it but the thing that messed you up on positioning was not cleaning the pads after you pulled the old chip. Wick all that solder off, clean the flux away with alcohol, then apply a TINY amount of flux to the pads, apply heat to the board and flow a VERY small amount of fresh solder so they pads stay flat and don't blob up.
Then the chip will want to center its self and the board will be pre-heated. Reflux a small amount on the pins and apply heat. The chip will suck right into position.
Remove heat and inspect with a microscope.
like many others have said remove with the hot air, clean the pads and tack the corners. The best flux to use is Amtec bga rework flux it. It just takes time and practice to get better so I say you did a great job for a first time, the fact that it worked is the main thing. 😁
Been there with some of my attempts with SMD soldering. I'm impressed just how resilient the chips are. I always have worried that even just a little extra heat would do them in. Glad you were successful in the end!
Thank you very much Adrian for another great video!
About the 5V tolerant inputs, I've seen some people adding something like a 1k series resistor to those inputs, so it will help "burning" the voltage difference and reduce the risks of damaging the IC.
I just started with SMD soldering with some practice kits I bought on Amazon and I've learned with the solder bridges, if you put a glob of flux on there (I use the thick stuff) and completely clean off the soldering iron tip, you can drag it across and the excess solder will collect on the iron. Sometimes have to clean the tip and go back over it a couple of times if there's a lot, but if it's too much I use the solder braid and redo the pin if too much comes off. .
Actually I never did SMD repairs but I'm happy with your video because it shows what may happen at a first try... Thanks for that.
i would say the biggest mistake was just not cleaning the solder off the pads. you did good getting it on
Don't use wick to clean up shorts between pins. Clean your iron, add flux, and make another pass with the iron, and the iron will wick up the extra solder without desoldering the pins. If it doesn't clear it up, repeat: clean tip, more flux, make another pass. You'll have a much easier time with it that way.
Also many people said that, but cleaning up the pads after desoldering the old chip is always a good idea. You'll have an easier time aligning the chip, and you're not mixing solder chemistries.
I'm awful at smd soldering too, but your video did prompt me to finally buy a little wifi microscope so I hope using it will help me improve!
This brings back bad memories of assembling boards with 0.5mm ribbon cable connectors. The pins kept bridging under the connector, and even after checking them repeatedly with a meter and finding no shorts, they still shorted and burned.
"You can't fix this car, Spiccoli!"
"I can fix this. My dad's a TV repair man and has got the ultimate set of tools." 🤣
I envision if I were ever to solder it would play out much like yours did, except without the solder success at the end!
This reminds of my first few attempts to stick chips on the boards. The scare of getting solder bridges especially on low pitch QPFs makes you think pre-tinning pads is a good idea; but good solder joints requires getting both pin and pads hot and as flush as possible; using enough solder, not too much, and a quality flux makes drag soldering easy and only viable option when using soldering iron.
Soldering requires a delicate thermal and mechanical conditions and you only learn it by doing it and learning from your mistakes and physical reasons behind those mistakes.
Hey Good job learning! You can only learn by doing! I think your biggest tripping point was the super tiny hot air nozzle. you have to heat the whole chip area at the same time so a bigger nozzle would have helped alot! But yea I think the proper way would have been to after removing the old chip use the braid to wick the solder pads clean. Then tack the corners and then solder the sides that werent tacked and then solder the sides that were tacked. Love your videos! You are such a character!
this is soooo relatable.. should be titled... : "How everyones first 20 attempts at soldering/reflowing SMD parts ( even with capable tools)" you are not alone.. and NO it is NOT "as easy as". Those who says that you know has never done it before.
I've only done one SMD chip before, but what I did was line up the chip and put an alligator clip to hold it in place (which was a tip in the instructions I was following). I think doing the same might have saved you a lot of fiddling with the movement. I too have a cheap hot-air station, but I ignored using it. I just soldered the side away from the clip with my overly-large iron, removed the alligator clip, and then soldered the other side. At the end I had two pins bridged, but just wiped them with a clean tip and it wicked away the right amount of solder - which I consider pretty lucky given my lack of experience/skill soldering.
Louis Rosmann aprooves the right amount of flux. - the bigger the blob, the better the job.
God, Adrian, you're obviously the quite type! I would have thrown the pcb through the window 3 times... Maybe that's why I don’t often solder smd! Thanks for sharing 👍
Learning from failures is way more effective than learning from perfection.
LOL! This was so painful to watch, but you did a good job. The hot air rework station is good for REMOVING surface mount components. I'd have removed all the old solder after removing the old chip (making the surface flat), put the new chip on, tack it in place, then just solder the pins with the SMD hoof (or a J tip). I've been using Kester 951 no clean flux which has worked okay, and recently encountered some sticky flux on a board I was removing components from, and it behaved exactly as I though it would, so I'm probably going to switch the type of flux I use when I run out (I also have an MG Chem flux pen).
Another cool and informative video. The capture solution fail was funny. I hate when I do a project like this and end up thinking I missed something because of such silly things. A note on the capture device, I use an evga xr1 lite on my test bench. It has a passthrough HDMI port which comes in handy if I'm building an adapter for display and I get a result like yours. Also I find the proper soldering iron tip with some decent flux and solder is way faster than air and less likely to heat these smds to failure. The iron only passes over a region of the IC at any given time as opposed to heating the whole package with air. That looks like the same scope as I use lol. Earned a sub👍
For smaller chips I find picking a nozzle that's about the size of the chip and blowing straight down on it (with some motion to make sure I hit the pins) does a good job. For example, on a QFP I'd pick a square nozzle that's slightly larger. For a long package like a SOIC I use a round nozzle with a diameter about the width of the chip plus leads. I'd usually rather overheat the chip than the board--the chip usually tolerates it better and the epoxy casing doesn't seem to absorb heat as easily as some PCB surfaces. For larger QFPs (like the ASICs in Sega consoles) it might be worth it to invest in some specialized QFP nozzles.
Also, pretty much all hot-air desoldering is made easier with board preheating. The hotter the overall temperature of the board, the less heat will get drawn away from the area you're working on. Heating the whole board slowly and evenly also makes it less likely you will warp or otherwise thermally stress it. I think you can heat most circuit boards to 100 Celsius without damage--just beware that you don't use a preheating method that can cause hot spots or overshoot your target temperature (like infrared).
Oh yes... soldering SMD is a nightmare. But your mishap gave me a good chuckle cause I couldn't help to think that you gave new meaning to the "+/- 1 error" that is common in programming 😉 - I think the "let the solder pull the chip" trick works regardless of the chip size, because: larger chip, more pins. It should be proportional force to help pull the chip into position, but whenever you push down on the chip it's slipping away.
Not that my experience matters but, I recommend removing old solder and then using solder paste with the hot air. The chip and other small parts don't move with it.
Solder paste is a mess, whit air they spread all over. Use solder iron (dont take to much time whit good solder flux and chisel tip) or hot air
@@yoyomismo2052 I don't have any problems with it. I use a syringe and clean up with Alcohol afterwards. We all find our own way; with my shaky hands, it works best for me.
Solder paste is too much of a pain without proper stencils... and it's usually too thick to apply manually.. though you can mix it with a bit of alcohol or thinner flux to make it a bit more runny. You'll end up wicking most of the excess away though, or worse - getting unmelted paste stuck under the chip!
Can't say I'd recommend this method for repairs over just tinning the pads + hot air, although for a leaded device like this, I would use hot air with a much wider nozzle or ChipQuik alloy to remove, clean the pads, then place the device by hand either pin-by-pin for this 0.8mm device, or drag soldering + wick for smaller pitch devices.
Even if you happened to have a stencil available for the device's pads, it's very unlikely to fit on an otherwise already populated board.
I agree with tommy, solder paste is alot easier, a good paste wont create much mess, also the smd parts will move in place easily without much fuss. You can then use a small soldering iron tip to cleanup if need be with some flux.