Show HN: PCBs with Full-Color Graphics

Additionally, others have gotten very, very good at putting alternative coatings on PCB. You can do remarkable work with spray paint and a vinyl stencil. Others have done multiple colors of soldermask on the same board. You can get very good results with black and white silkscreen, and using the standard complement of soldermask colors, something any board house can do very easily.

The problem with _all_ of these solutions is that these coatings do not work in a reflow oven. The issue with UV printing is that you can not put it through a reflow oven. This is important, because you do not want to put the coating/image on after you populate and solder -- parts would get in the way, etc.

The solution I've found is pad printing [2]. This is a process that is similar to silkscreening t-shirts, but instead of pushing ink through a screen, a design is picked up by a silicone pad and deposited on a PCB. I've done this with 'blockchain token Tide Pods' (I made a blockchain of Tide Pods), and various designs for other 'artistic' PCBs. Pad printing also has the advantage in that every city has a shop that does pad printing, and provided the design you want to print is small enough, this is very easy to contract out. Pad printing is highly geared towards mass-production, whereas UV printing is low-volume on the order of dozens or hundreds of units.

This isn't to diminish how cool this is. There's an entire community of people building artistic PCBs out there that would love this capability. Only wish there was a bit more information about obtaining, setting up, and producing UV color PCBs

[1]https://imgur.com/wgmO1jK [2]https://www.youtube.com/watch?v=4rTrSIKjpNY

https://github.com/badgeek/svg2shenzhen/

If every ground point was black, and every V+ trace coloured red, it would help students not to short out their boards.

If you're interested in graphics using more traditional manufacturing, halftone can work well on PCBs. It's not too hard to do with your favourite raster graphics and CAD packages. If you use KiCad, here's a shameless plug for a toy project: https://github.com/ianrrees/kicad_halftone .

Second, I hadn't heard of the CC public patent license before, but it seems like a good way to go to keep an idea "free", rather than not pursue a patent.

I have a bunch of experience making PCBs at home using laser printer toner transfer. Next time I have an opportunity to build something, I will try to transfer an underlying image onto the silk side of a one-sided PCB, followed by the silk screen layer itself. Probably, I will merge the images digitally to do it in one transfer.

Typically, PCB layout software doesn't support that sort of thing, but when I do toner transfer, the artwork ultimately ends up in a mirror-imaged .PNG file anyway. That can easily be merged with color imagery.

Edit: https://en.wikipedia.org/wiki/Flatbed_digital_printer has some info on UV printers, seems you can get inks which are themselves curable under UV.

Can you talk a bit about how the PCBs will work in production?

How do component silk screens work? What about fiducial marks? Do machine vision systems (when looking for fiducials) cope with the graphics or do they get confused?