日本語
I am about to create my first home made PCB using photo resist board. I have a UV box, and a transparency with the artwork. All I need to do is place the artwork on the glass, then the board on top of it, close the lid, and set the timer for a few seconds.
I am not sure how long I need to set the UV timer for, does anyone know?
- Comments(1)
A****min
Feb 13.2020, 16:57:48
It depends, you should make test board where you cover parts of it after some time of exposure. So you can test different exposure times on the one board. Start from 10-15s. It also depends on transparency contrast. If it is bad you will have a hard time as unwanted places will be also exposed. You would need very precise exposure time. If contrast is really good then exposure time is very tolerant and can be changed by couple of times without huge impact on board quality. Which photoresist do you use? From my experience, positive 20 and other positive ones are not worth to mess with. Especially if you print photo-mask on regular inkjet printer (laser is usually even worse). Negative dry films are the way to go as they are more process tolerant, have better resistance to etchant and overall result in better quality.
