pcb material with transparant substrate

[t850]

hi there,

this really isn't a circuit engineering question, but perhaps someone can give me a lead on how to look for a particular kind of copper board (if it exists).

i'm looking for a single-sided copper board that has a transparent substrate. what i need to do is to create a stencil behind which i'll place light sources. the issue is that the stencil has loops in it, so the idea is to use copper etching techniques to remove areas i want light to show through.

any ideas?

 

[t850]

just one more thing... the reason i want to etch away the stencil image is that i don't want it to be visible when the light source is off. the top layer will probably be frosted, but i think i can take care of that separately.

 

[logbook]

I don’t think you will find a standard pcb material which is transparent. It is also not clear if you actually need a transparent pcb. Why copper for example? Why not just silk screen black ink on a transparent substrate. You should be able to get a sign writing company to produce what you want. There are plenty on the NET. Produce the artwork and they will do the rest.

If the job were small you could use quartz, but that would be expensive and not more than about 2cm on a side (probably).

 

[t850]

hi,

silk-screening could possibly work - i'll look into that. i'd still like to pursue the etching idea because i can envision a project which puts the lights behind the transparent side of the pcb (instead of the copper side).

 

[IRstuff]

sounds like you don't actually intend to have circuitry, so a copper PCB is gross overkill.

Sounds like something more appropos with a Lightscribe inkjet or similar printer than can take flat substrates. You could use straight acrylic as the substrate

TTFN

FAQ731-376

 

[bogeyman]

If you must use copper try bonding a sheet of thin copper shim say 25 micron thick to a sheet of clear plastic or even glass and then etch that just like a pcb.

 

[felixc]

Depending of how solid you want this pcb to be, perhaps that you can get what you want if you go to see companies that are making flexible pc boards, or those that are making membrane keypads. They have transparent copper films that they laminate with mylars to produce these keypads that you find on so many instruments these days. They can etch these films to get the keyboard pattern that you wish.

 

[btrueblood]

Take IRstuff's suggestion for inkjet printing a step further: put a sheet of that acetate transparency material for overhead projectors into your laser printer, and print any design you want, then laminate/bond the acetate to whatever transparent/translucent plastic you want to use (acrylic, polycarbonate).

 

[TurboXS]

Gosh..........

Remember the days when we used to lay out PCBs using film and tape?

 

[t850]

these are all great ideas - thanks!

 

[zeitghost]

Don't know how transparent you want it, but FR4 is pretty translucent when it hasn't got solder resist on it... the disadvantage is the "watermarks" that the manufacturers put in it...