CopperFill TINNIT PCB method
Just an Idea
Back in college some 25 years ago, I made some circuit boards and used a product called TINNIT to tin the bare copper. This prevents rust and provides a good solderable surface as well. What you do is you etch your circuit board and then you put the contents of two bags containing white crystals into a tray of warm water, immerse the board a minute or two, and watch as the copper is magically coated with tin. It's important to use both bags in the solution because they are different chemicals, both necessary, that mix together in the water.
Fast forward some 25 years and today we are clamoring to create circuit boards with today's 3D printing technology. There are some great ways to do it out there but all of them are "flat" circuit boards. I want to make circuits in 3D so they can, for example, line the housing of an aircraft or run along the surface of an LED emitter strip that is organically shaped. Or whatever, we want 3D circuits from our 3D printers right? So I dreamed up a possible technique that remains to be tested.
It's based on TINNIT and CopperFill. Whatever. You get some CopperFill and print out a test shape, lightly sand the test shape to expose the copper powder to air, then immerse it in a solution of TINNIT. I have read that the TINNIT will leave a 10 micron thick layer on copper and certainly the copper particles in CopperFill are way closer than that, so yeah the TINNIT should bridge the gaps between the copper particles, fusing together to form a conductor. It may be a thin layer but it'll be conductive and we can then plate it or solder over it or use some creative ridged or space-filling meshed shape for the traces to improve the current handling and toughness of the TINNIT.
Anyway I think it might work but I don't have any CopperFill to test it with and my printer is down. I do have the TINNIT though, which you can buy from Amazon.com if you like - it's fairly inexpensive. Does anyone want to run a test? or send me a few inches of CopperFill? We should probably check this one out.
Les
