PatStarace

  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. https://www.adafruit.com/products/1894 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 poof! 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. I have one more to make like this. This is a great technique prototyping Wearable Technology! ~Pat Starace