Hello Michael! :-) On Fri, Jul 8, 2011 at 8:18 PM, Michael Schwingen <[email protected]> wrote: > Am 07/08/2011 08:30 PM, schrieb Tomek CEDRO: > (..) Still I don't know any sensible method >> to make drills metalization at home to produce advanced two layer >> pcb... maybe you guys know some tricks? :- > Simply drill the holes and solder both sides - with a thin wire if there > is no THT pin. This may be a bit painful, but works quite well if you > take care during layout so that you do not place vias under parts.
Yes, this is the obvious solution for low count VIAs, but I am wondering on making something more useful to connect both layers on PAD (that is when also some component use that hole) - this is especially painful on connectors or other parts that hide top layer when element is mounted... > BTW: I found that PCB material that comes pre-coated with the photo mask > works *way* better than positive-20, because you get consistent exposure > times. Also, positive-20 tends to get bad shortly after the "best > before" date, which was about a year when I used the stuff, while the > pre-coated material can be stored a lot longer. Thank you for this advice - I am actually using small 100ml Positiv20 spray far beyond expiration (03/09) and it works fine ha! I noticed the NaOH must be fresh and the light source is very important (mentioned philips 14552 12V/75W halogen/uv lamp gives best results of all) and it can overcome Positive20 limitiations.. maybe thats also because I give thick layer of fotopositive (dry it in oven) and strong lamp. This photolitography method is really nice and far more reliable than thermal-transfer, its not expensive, I can recommend it to anyone that want to make precise pcb at home :-) For my applications this quality is enough, maybe pre-coated boards are better but also far more expensive... Still, no solution/idea on how to make pads metalization at home safely... there is a clear field for a patent, hey inventors wake up! :-) Best regards! :-) Tomek -- CeDeROM, SQ7MHZ, http://www.tomek.cedro.info _______________________________________________ Openocd-development mailing list [email protected] https://lists.berlios.de/mailman/listinfo/openocd-development
