Clear PCB

mctrivia

Is it possible to get a PCB made clear? Would make for a cool touch screen. Surface mount rear projecting leds on back exposed thin copper traces on front.

4Alex

I have never seen any 'clear' pcb substrate. However, I don't see why someone couldn't buy the thin copper foil that is normally applied to FR4 fiberglass substrate and apply it to, say, a polycarbonate 'clear' substrate with the same manufacturing capabilities. My first option would be thick Lexan sheets, widely available in the trade in all sort of thicknesses. Your question is definitely intriguing. There's an interesting marketing prospect to it. I don't know 'how' the thin copper foil is 'glued' to FR4 but it is clear (no pun intended) that fiberglass is no more prone to adhesives than polycarbonate-based plastics (fiberglass is an epoxy matrix). So results should be comparable. I am a bit tied for now to follow on this but finding thin copper foil used in pcb manufacturing is certainly one way to solve your problem. Then it's probably up to you to make your own custom-made application. BTW, one big OEM is 3M.

Cheers,

Alex

mctrivia

now that i think about it i have seen clear flexible pcbs but know clue where they were made. Found someone that did it by hand on the internet. mookstar.wordpress.com/2008/03/15/some-more-transparent-pcb-experiments/

4Alex

Thinking of it, depending on your application, perhaps you could explore flex cables. They are thin, yellowish, copper-traced flex cable made to order to pretty much any size you want, allows for direct soldering of components, and are definitely transparent. Another alternative comes from the custom-made keypad industry. They print conductive traces of silver ink on transparent Lexan substrate. Most of them even allow pads for 'soldering' (using conductive epoxy) of components (mainly leds, though).

Cheers,

Alex

mojorizing

This product might work....

http://www.laserpcb.com/

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Bad spellers of the world untie!

Cole Logan

That laserPCB looks pretty interesting. And if you already had a laser printer it looks to be about the cheapest and quickest way to make PCB

Paul Baker

The fiberglass substrate used for the common PCBs is translucent and when matched with a clear solder mask makes the final product look translucent, but you don't have a clear view through the entire thing. If you specify a vey thin thickness for the PCB it will look more transparent but will still be translucent. I have seen flex circuits that were completely clear, but almost all manufacturers offer either amber or green polyimide (plastic substrate used for flex circuits). So it's theoretically possible but you would have to find a flex circuit manufacturer and make a special deal with them (assumably at a higher production cost).

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Paul Baker

mctrivia

i use to make my own circuit boards all the time using my lazer printer, transparencies and photo sensitive boards. Cheap and works but hard to make double side, impossible to do more then 2 sides, and I almost killed myself once when I accidentally inhaled the ferric chloride used in the etching process.