Fred 453 Posted July 10, 2013 Author Share Posted July 10, 2013 I had some better results recently but had another extremely slow etch for this board. Then I dabbed it gently with a sponge during etching and it all started working. I suspect that I exposed and developed the etch resist OK, but then the "dissolved" resist just sat on the surface of the board and prevented etching. Or maybe it was a film of the oily sodium metasilicate developer. A quick dab with the sponge was all that was needed to dislodge it, so maybe bubble or spray etching would have done it too. The board's now been drilled and cut out. I decided to try solder paste stencilling so I'm just waiting for some mylar sheet to turn up so I can cut a stencil. I wasn't going to bother with tinning. I'm expecting at least one iteration of the board and I'm doing it partially to get some practice in on the board production. If it works and I can program it from a Launchpad then I'll add a couple more bits, connect the unused MCU pins, etc. Quote Link to post Share on other sites
Fred 453 Posted July 17, 2013 Author Share Posted July 17, 2013 Hairy dog's balls. I was very pleased with my first attempts at creating a solder paste stencil and reflowing with a hot air gun. I'd got the wrong footprint for the TPS77301 (top left - way too large!) but thought I'd still be able to program it via a Launchpad and test a few things. Unfortunately I also somehow swapped GND and Vcc on the MSP430. I'm shocked none of you spotted that. ;-) Oh well, that's why I'm making my own boards - for the quick turn around on my own screw ups. I should be able to green-wire that and check nothing else is seriously wrong before I do the next iteration. Quote Link to post Share on other sites
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