Success! A Flexible Printed Circuit Board. These boards are not easy to make, so I thought, and with a little work you can make a nifty Flexible PCB.
I used Adafruit’s Pyralux Flexible PCB Material.
I first tried to CNC it on my engraver. As awesome as my engraver is (similar to a LPKF machine), I couldn’t engrave the copper enough without going through the backing material. I had high hopes of engraving it, and I tried small steps in my cut depth, .002″, then another .001″, and another .001″, then bazinga! I went through the backing. The backing is only 1 or 2 mils thick, and this was too hard to mechanically engrave without inadvertently cutting through, so I decided to take another route.
Next I tried by cutting a stencil on my Roland Vinyl Cutter. First results were pretty good (for a vinyl cutter, though I needed to add more time to the etching process). Inexpensive Vinyl Cutters are quite quite popular, and I’d imagine even a Cricut would do the job. I had to delete any fine text I would have had on the board as the cutter wouldn’t hold that resolution.
Using transfer film, I applied the vinyl to the board as a resist, and after a 20 minute bath in etching fluid the board was etched to the backing material. I cut more vinyl for the pads, and hand placed them on the board. Then I covered the PCB with a cool red epoxy polymer to act as a solder mask and protect the board.
Finally, the conductive material you’ve known you wanted but never knew you could have, its a sheet of flex PCB material! This is the stuff used to make flexible circuits, but raw and unetched. You can treat it just like 1 oz copper clad, etch it with ferric chloride (or other PCB etching systems) or cut with scissors.
Pyralux is the brand name of Dupont’s flex PCB material that’s used in cell phones and other small circuits. One side of it’s 1 oz copper while the other side is polyamide for strength and flexibility. The material can be manipulated through and around small areas and won’t crack as easily as copper tape. Pyralux is used in a ton of consumer-grade electronics and one of the reasons why things like your cell phones have advanced from bulky and cumbersome to miniature super computers.
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