FR = Fire retardant, type 4 (impregnated glass mat with transition temp of 160˚C) In the olden days there was also FR-5 for higher heat/higher budget applications like furnace controllers and aerospace, and most of the stuff they used to sell at RadioShack was FR-2 which is resin impregnated cellulose material for lower temps and low budget. There were others but after 30 years of designing boards, those are the FR series I've used. Today it's a whole new world and the kids have no idea how easy vendors like PCBWay have made it for us.
Small pcs of PCB material can also be used as capacitors. I use this method for making a capacitive distributed antenna. You can calculate values by measuring 1 sq inch and scaling it up or down
Gold is just a protective layer and works well for edge connectors. Copper is a better conductor and I don't suppose the thin layer of gold that is typically applied makes much difference either way.
From best conductor: it goes silver copper, gold, zinc, nickle, iron, tin, lead... with silver being about 6 times more conductive than iron. Silver, copper, and gold are close in conductivity... but, of course gold doesn't tarnish as much a silver, and silver not as much as copper.
Actually, I understand "FR" stands for "Fire Retardant". The "4" indicates epoxy resin.
FR = Fire retardant, type 4 (impregnated glass mat with transition temp of 160˚C)
In the olden days there was also FR-5 for higher heat/higher budget applications like furnace controllers and aerospace, and most of the stuff they used to sell at RadioShack was FR-2 which is resin impregnated cellulose material for lower temps and low budget. There were others but after 30 years of designing boards, those are the FR series I've used. Today it's a whole new world and the kids have no idea how easy vendors like PCBWay have made it for us.
Small pcs of PCB material can also be used as capacitors. I use this method for making a capacitive distributed antenna. You can calculate values by measuring 1 sq inch and scaling it up or down
I just want to say even though your video hasn't got a ton of attention, it was very imformative and useful to me, and thanks for making them!
I think the plated though holes are done right after drilling and before the traces are etched as they need current flow between the planes to plate.
Gold is just a protective layer and works well for edge connectors. Copper is a better conductor and I don't suppose the thin layer of gold that is typically applied makes much difference either way.
And gold is excellent for soldering.
Actually silver have the best conductivity.
ENIG Gold finishes sure look pretty!
You'll want hard gold for edge connectors. ENIG is too soft.
From best conductor: it goes silver copper, gold, zinc, nickle, iron, tin, lead... with silver being about 6 times more conductive than iron. Silver, copper, and gold are close in conductivity... but, of course gold doesn't tarnish as much a silver, and silver not as much as copper.