Werner Almesberger wrote: > Rene Harder wrote: > >> The chemical deposition of organometallic compounds (OSP) is becoming >> more and more popular, and you'll find it in prototype spec quite often >> these days. However I have no idea about long time stability (have never >> used it myself) >> > > All I know about OSP I learned on the Web ;-) How do unsoldered pads > perform (NC, test pads) ? Can you leave them "clean" or do you apply > solder paste as a protection ? > > Also, with stability, I'm less concerned about whether the board will > still work in ten years, but how long we can store it between PCB and > SMT. If that time is very short, that may be a problem. There are > always surprises ... > >
I agree, these are interesting questions, unfortunately I cannot give you an proper answer. My Electronic Materials and Processes Handbook doesn't really handle OSP. There is a small section about organic compound (e.g. conductive epoxies) as solder finish though, but this seems to be an outdated technology (although the book is not too old, it's from 2004). I guess it'll be time for a new one. >> Indeed, that makes things more complicated However, there are companies >> who have boards with an overall thickness of 0.31" or 0.40" for 6 >> layer[1] or 0.48" for 8 layer[2] in their standard specs. >> > > This board is begging for six layers ;-) > Yes it really does. :-D _______________________________________________ gta02-core mailing list [email protected] https://lists.openmoko.org/mailman/listinfo/gta02-core
