Have the the microvia filled with epoxy and plated over to eliminate the problem with solder going into the hole. Conductive silver epoxy is often used.
Jeff Condit. > Dear Members, > > We have serveral very high density PCB with microvias on pads, the microvia > is 4 to 5 mil, recently, our SMT house tell us two components contains > microvia on pad are tombstoning after reflow sporadically, and maybe the > reason is the pad with microvia on it need more solder when printing, since > there is a hole on pad, so the stress is unblanced during reflow, thus > tombstone occured. > > Does any one have more experience on this? if you use microvia on pad in > your design? I heard copper-Filled Microvias before, No holes observable > after plating, but I do not know how to do this, where can I find more > technical paper about this? Is it very expensive? > > Your input is very appreciated! > > Best Regards, > Luo. > > --------------------------------------------- This message was sent using Sunset Net Webmail. http://www.sunset.net/ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[EMAIL PROTECTED] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
