[sdiy] Transparent spots on front panels - how to do?

[brianw]

It's certainly possible, but beware that not all FR4 material is the same color, nor does it all have identical translucency. You probably need to get samples and then make sure to specify a particular brand of material when ordering the boards.

I designed a board using clear solder mask, which was beautiful because it shows all the copper without allowing the copper to tarnish due to exposure to the air. However, different production runs ended up being different colors around the copper because FR4 material ranged from light tan to dark brown. I never tried to shine lights through it, but just with normal lighting there was a huge difference. If I had to guess, the brown was not as translucent as the tan.

The nice thing about FR4 is that everything meets a standard, and you can be sure of the performance across different fabrication houses, but that standard includes neither color nor translucency.

Brian


On Jan 27, 2024, at 1:48 PM, Scott Bernardi wrote:
> You see some modules that have transparent areas on the front panel that are lit from behind.  How is that done? Is it possible on a regular DIY FR4 PCB panel?