New high vacuum system
Вставка
- Опубліковано 6 жов 2024
- I'm building a physical vapor deposition rig, which will be an interesting tool for creating optical coatings, SEM sample preparation, and maybe even thin film transistors. So far, I only have the pump and Penning gauge connected to the chamber. Soon, I'll have high-current and high-voltage ports in the base plate for controlling the deposition process.
www.allorings.c...
I have a BS in mechanical engineering, but learning fundamentals in university is pretty well removed from using practical knowledge in everyday jobs. Also, most university engineering programs do not encourage hacking or hands-on work, which is what interests me the most.
Hey Ben, your videos blow my mind
Thanks -- I really appreciate it. Keep in mind that life is often not so linear. I've made many small choices over the years that led me to having my shop, but I never consciously made a single decision to build one from the ground up (in fact, the building was designed by my house's previous owner). Keep doing what you want to do on a daily basis, and you'll end up in a good place.
I bought the jar on eBay about 5-6 years ago. I had to search a while, since thick vacuum-rated jars are rare. The seal is a proper buna-n bell jar seal, but the upper edge is falling apart - hence the tape. The lower edge still makes a good seal.
Yes, the inside of the jar will definitely get coated. It's possible to use baffles and shields to direct the flow of vapor (and keep most of it on the target), but it's also pretty easy to wipe the coating off the glass -- probably depends on the material though.
Ben's abrupt endings always leaving me hanging. :(
I'd like to have another bell jar, but I can use my existing jar until I do. They are expensive! Be glad that you found a vacuum-rated one at a fleamarket.
Just a safety note you should make a wire cloth screen around the outside of the bell jar
on the rare event it should implode you would be at great risk of serious injury.
On my 18” OD x 24” jar I used 1/4” galvanized wire mesh and two long hose clamps
around the OD of the jar to secure the cage to the jar this also provided a means to
attach my counter weight hoist for raising the bell jar.
Just wanted to let you know that all of your videos make my jaw drop. I love watching them. I hope there is a point in my life where I can settle down and design my own lab from the ground up like you have.
I made a little smaller PVD about a year ago by things i got and could make very shiny mirros on microscope slides both aluminium and copper surfaces and the copper really looked nice. Got problems with oil from the backingpump though after a week but i didn´t have had time to deal with it.
And lately i have also got quite a big turbopump and some wide SS tubes that i will put together to a much bigger chamber then the other one, i only need time. Will be interesting to follow your progress.
Once again Ben great vid, you have a lot of passion for science! I used to work with ICP-MS for metals analysis which required an extremely good vacuum. We used an Edwards roughing pump coupled with a turbomolecular pump which was attached to the underside of the ion chamber. If a turbo pump failed it was in the order of $20k to replace!! I believe it was water cooled too.
Ben, I think even a video of you showing the proper technique for clipping toenails would be intriguing. :)
Agreed. I would also love to hear what to look for in a CNC machine and what isn't very important.
For people interested in machining videos I highly recommend looking up tubalcain and kef791. I have learned a lot about machining from both these guys.
Would love to have a tutorial on machining or anything else you choose to do. Your projects are mind blowing. Please keep the coming.
Looks like i'm not the only one that would like to see a tutorial on machining...
OMG, I love these videos so much. And, do you really have to ask whether we want more videos? We want more. Having one of your videos show up in the subscription is like a little present.
I would love to see a tutorial on machining from you. It's something I've always had someone else do for me because I never knew how to do it properly. I'd like to do it myself.
I like your plans for this. As I understand it, this sort of device is used to "chrome plate" plastic, with aluminum.
Seriously, I think Ben Krasnow and Jeri Ellsworth working together could make Chris Gammell's chip printing dream a reality.
No need to, just depends on what youre doing. Some telescope mirror coaters or most use all glass or at least a big sight glass to watch the coating process. As Im sure you know glass in the shape of an egg, oval, and cylinder is very very strong.
I spent a few years in high school trying to teach myself a bit of machining when I was handed nothing but a CNC 3-axis stepper mill and a copy of MasterCAM with no background knowledge...it would be interesting to see how things are actually supposed to work.
That's a really cool system. I actually do a bit of PVD at work. You seem to have a pretty good grasp on high vacuum.
Few comments. You may want to start looking into a film growth monitor.
You also might want to consider adding a cryopump as those are easy as hell.
You should build a fusor (a type of simple fusion reactor). You have all the stuff, I mean a vacuum chamber, high voltage power supplies and so on.
Great video. A machining tutorial would be great - i'd love to see how you set up the drill, and drill path.. Cheers!
Those diffusion pumps are obscenely expensive as new (5k the simplest 10k the one with pneumatic valve!) in fact there are turbo pumps significantly cheaper new with 2/3 the pumping speed! why is that? they are basically a pipe with a cooling coil brazed to it and a heater at the bottom, the ejector assembly isn't more complex than the internals of a car muffler, Edwards brags about their pumps being fractionating but the thing is, almost all diffusion pumps form the mid 40s to now are fractionating, the fractionating tech is just a danm pipe from the bottom of the boiler to the top ejector. Im building my own due the ridiculous prices :(
I think it would at least work for the 100% reflective end, the issue is the partial reflector, and also getting the ends of the crystal flat and parallel enough for the coating to be any use.
I have yet to watch kef791, but can certainly say tubalcain is a highly exp machinist worth watching.
Would love to see some machining vids from you! Just picked up a used micro mill a couple weeks ago.
Where did you get the bell jar? It looks like you put black duct tape around the base for the seal. (and I thumbed up a comment for a machining tutorial)
Try making aerogel sticks and see if they can be used as filler in composites (instead of other heavier foams or material that absorbs heavy resin). Measure how much resin by weight aerogel absorbs (machine the top of the aerogel in CNC machine, smear resin on top of the aerogel, then let it harden, then run the same CNC machining program, measure the weight of the aerogel and the thing its held by before and after. Ensure resin does not go over the edge).
back in the mid 80's, I worked with a couple sputtering machines...I think we were pulling 10x-7 vacuums alcatel mechanical pumps with a gate valve opening to a cryo pump...they claimed a single fingerprint would not allow us to pull vacuum....we were sputtering chrome , nickel and gold over a glass substrate. Occasionally we would sputter a thin layer of chrome over a failed component for SEM ... I think we used 400 V DC and .99999 argon ...all the fancy non-outgassing grease...good times...
Hi Ben,
I've worked for 8 years in a Wafer Fab Thin Film section so have a vast knowledge of high vacuum systems and Thin Film plasma deposition, mainly on Applied Materials machines. If you've any questions I maybe able to help or ask a friend.
Chris..
Come on Ben, all of us arm chair engineers are anxiously awaiting your next video. Dancing with the Stars is over for the season and we have nothing to do.
Best regards.
Definitely a machining tutorial, especially for cutting feed speeds and tool bits :)
Yes please on a machining tutorial. MIT have a good comprehensive series that I'm about 1/2 through but it would be good to hear your opinions.
Hi Ben, a machining tutorial sounds interesting.
You're right. I should probably use a metal cage.
A machining tutorial would be great. so would a build your own CNC machine for us starters would be nice too, if you've ever done something like that.
hes a busy man. although i wouldnt mind seeing full builds if they are already recorded, instead of editing them out :)
Ben anything you do is interesting ..!
Another vote for a machining tutorial. And thanks for another informative video.
Nice video Ben. plz do a machining tutorial!
A machining tutorial would be cool, but I don't think many people realise the risks and costs (the price of those machines may be higher than what your car costs!) that are involved in machining. Actually I think many don't even know about the existence of things like cutting speeds and feed rates.
Its not like you turn on the machine, load in a drawing and off it goes... It actually takes expertise and experience.
Aside of that, there are many different languages like Heidenhain and Siemens.
A machining tutorial? From Ben Krasnow? Yes please!
Ooo, vapor deposition.
I have some Indium metal that I would like to donate to your cause if you would like it.
It should make for some great transparent conductors.
A machining tutorial would be really cool
I've had an impression that diffusion pump is a bad choose for trying to make thin film transistors due to (very little) oil contamination of the chamber. Have you thought about turbomolecular pump? ebay have some cheap items (~1000$)
Another YES on the machining!
EVERYTHING you do is interesting! Please post more videos ;-)
Hi Ben, awesome videos. I'm trying to build something similar. I like the glass belljar approach. However, my guess is that the L-Seal of the belljar is your limiting factor on how good a vacuum you get? Buna-N is not as good as for example Viton (as far as I understand) but the selection of L seals is limited so probably not an option(?) How good a vaccum do you get with your system? Thanks :)
A machining tutorial would be awesome.
nice you could make thin film photovoltaic cells
I have a vision of the future... Ben and Jeri's (Ellsworth) Home Semiconductor Fab.
I would love to see more tutorials.
Tutorial on machining would be awesome!
To answer the quest @1:30 about CNC machining. there is a UA-cam channel called The Geek Group and they have a lot of stuff about CNC machining.
BTW: did you go to maker faire in Seattle this month?
Not really. Its more shooting around big volent clusters of oil below the vacuum chamber and if slow light air happens to drift down it gets hurled into the exhaust of the pump.
A machining tutorial would be cool!
Yes Please! A tutorial on getting started with machining.
Ben, if you don't mind my asking, what is your profession? I really enjoy your videos.
Do you need another glass bell? I found one at a flea market and I'd love to know what it's worth. It's much thicker than display pieces and has a ground glass flange on the bottom
I'm curious. Wouldn't the deposition coat the inside of the bell jar, making it opaque? Is there something that prevents it (e.g. not being grounded prevents it or something) or are the coatings so thin making it opaque really isn't an issue. Or, I guess, it could just be easy to clean.
Ben - search on eBay for "Complete High Vacuum Bell Jar Evaporator Optical Coating / Deposition System" - I just saw an item with this title which looks like it might be very helpful to you.
make some bulk diamond in your deposition chamber. apparently tequila has the right ratio of C, H and O to make diamond this way.
Do you plan any research or experiments on graphene? I enjoy most all of your videos.
Best regards
After you finish the heater, how about some tool coatings like TiC?
a machining tutorial would be great!!
Machining tutorial? ABSOLUTELY!
I vote yes on the machining tutorial!
Definitely a machining tutorial!
sure we want a tutorial on machining, please :)
i would like to see a machining tutorial
What about stacking may be three or four pumps to increase the vacuum speed?
Just wondering, what types of degrees or schooling have you received? I'm currently pursuing a chemical engineering degree, so I have dealt with or seen at least a small portion of the equipment you have designed, but never before have I seen anyone with enough ambition to build any of these pieces. Especially equipment as complex as the SEM.
Yes on machining!!!!!!!!!!!!
Would love some insight to machining.
Yeah, the machining tutorial would be nice. But I never knew one could build a CNC drill by himself... Seems like very complicated stuff.
Great work,
What is the recommended vacuum pressure to reach in order to achieve PVD?
Based on your experiments will a 2mBar vacuum pump be sufficient ?, is the Diffusion pump necessary ?
Your pump isn't going to be able to generate enough vacuum to do most PVD techniques, i think you might be able to do some very slow sputtering of copper or gold but it wont work very well at that pressure. I don't know much about PVD techniques but seems the most common ones work from .3 Torr (.40 mBar) for sputtering of some inert metals but usually its done at about 6x10-2 Torr (.079mBar) some PVD techniques can go down to 3x10-6 Torr (7.9x10-6 mBar) like evaporation of aluminum for optical coatings.
Probably you already know this, specially because your comment is 1 year old but well maybe i can help someone with this same inquiry.
When choosing a vacuum pump look at its specifications, pay special attention to the graph of pumping speed vs pressure, ultimate pressure and pumping flow. Oil sealed rotary vane pumps and many other roughing pumps have a relatively constant pumping speed down to about .1 Torr then its pumping speed starts dropping very fast so its usually better to use a high vacuum pump (oil diffusion, turbomolecular, molecular drag) if you need to work below 5x10-2 Torr to avoid very long pump down times even if the rouging pump can reach such pressure.
Another thing is, like many high vacuum pumps, diffusion pumps can only work below certain pressure, above it wont work, usually you will read in the literature that such pressure its around 6x10-2 Torr (.08 mBar) but that's usually an average number for maximum throughput of old pumps they can work at slightly higher pressures but at lower pumping speeds. Modern diffusion pumps with an vapor ejector on the final stage can work down to 4x10-1 Torr (.53mBar) at max inlet load. However don't take it for granted, always check the specs first to avoid nasty surprises! most professional vacuum equipment is obscenely expensive and overpriced so those HVAC vacuum pumps are a great start for the amateur, also sometimes you can get good scores on the surplus market and get a professional vacuum pump with good life still left in it. Just but be careful as it could have been used to pump toxic gasses so take care when changing the oil. Getting into high vacuum pressures (below 9x10-4 Torr) its quite tough mainly due the prices but is doable if you are patient and have some spare money, also you have to be very careful with the materials, everything but some metals outgas like mad. Good luck!
Peace be upon you. I am Ehssan S. Hassan a PhD. Student in the physics department, college of science, the University of Al-mustansiriyah. I am a fan of the work you are doing. I wish you could send a diagram showing the diameter of the holes and the distance between them, for the surface you have installed.
Machining tutorials would be great!
Yes please a tutorial on machining!
Ho ok. Thanks for clearing out the confusion in my head!
Like a real life Tony Stark in his basement.. Thanks for vids
Doesn't work exactly that way. You'd need to upgrade both the primary and secondary pump, and you wouldn't gain much efficiency in the end. If pumping speed is a must, you need a big mechanical pump and a turbomolecular pump.
I'd love more tutorials :-)
so the diffusion pump works similarly to a venturi tube?
So how is it we can see through it and out the other side? ;-)
do you think something like this would work for mirroring laser crystal rods?
Have you ever used a Turbomolecular pump?
Why not fabricate your own metal carts? Angle iron is cheap plus you can build it to your own spec/needs.
I don't think you can learn machining in just "a tutorial", it takes a lot of experience to get good at it, and any type of CNC machine would probably be way more expensive than you think. You first have to learn manual machining before even thinking of learning CNC. You won't really learn how things like feed and cutting speeds work any other way. That aside, you need some really expensive parts if you want to build a machine yourself.
I really want to do something cool with a flask. Idk what to do
tutorial on high vacuum difusion pump!!!
machining tutorial, yes please!
Yep, tutorial for filming please.
Nice almost nothing in that Jar!
What Dow Corning grease are you using here?
Is there anything you don't know or can't make?? :)
you didn't say bye like you normally do...