I have tried my first positive photo resist etch. The light exposure / developing step went great. All the exposed parts of the PCB looked like copper and all the unexposed parts looked like photo resist. So far, so good. After rinsing and drying, I put my board in a tank of Radio Shack's best etching solution. Unfortunately, I don't have a good etching tank, just a pan. After stirring for 30 minutes, barely any of the copper was etched. After leaving it overnight, still only
1/2 of the copper is etched and some of my traces are starting to erode - aargh! I used to etch standard PCBs all the time with Radio Shack etchant with no problem (about 30 minutes etch time). Is there something special about photo resist PCBs that standard etchant won't work? Am I doing something wrong? Please help.BRW