PCB-etch

Instructables user ArduinoFun shows how to etch PCBs at home using a positive photo-resist. This method involves printing the PCB design on an inkjet transparency, exposing it under a UV light, developing in a basic solution, then etching in an acid.

Do you etch your own PCBs? What methods have you tried?

This is exactly how we etch prototype PCBs. Some of our tips and tricks are listed after the break.

Printing with ‘high quality black’ mode, something that mixes all the inkjet colors, gives the best UV resistance. We have to use two layers of transparency with black ink alone.

Put the ink side directly against the PCB for the best exposure. It lessens shadows and light creep through the plastic. Be sure to print the top-layer mirrored and the bottom normally.

We expose with a home tanning lamp directly over the PCB. The sensitized PCB and mask are justified in a picture frame. Exposure time is only 90 seconds with this method.

We print designs from Eagle to PDF, and then add text, graphics, and other elements in a page layout program.

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