Daan, If you have a spare board, try applying a spot of high temperature oil to a bga pad with a via and heat it to soldering temperature. Any outgassing of the via should be visually obvious. ( I am speaking here from theory, not practise, but it should work). Regards Eric Dawson > -----Original Message----- > From: d. terstegge [SMTP:[log in to unmask]] > Sent: Tuesday, May 28, 2002 11:37 AM > To: [log in to unmask] > Subject: [TN] Anti-voiding solder paste > > Dear Technetters, > > I'm having some problems with really big voids (up to 50% of the diameter) > in the solderjoints of BGA's. The problems occur on our only board that > has via's in the BGA-pads. The via's are filled and plated, so from the > outside you don't see they're there. > I'm quite sure that it's the board that's causing the problems, but the > boardvendor does not agree and thinks our solderpaste is causing it. > To prove that I'm right (or to solve the problem if the boardvendor is > right !) I'd like to do some tests with a solderpaste that's known to > cause a minimal amount of voiding. From earlier discussions I learned that > such solderpastes exist. > Does anyone have a recommendation for such a solderpaste ? > > Daan Terstegge > SMT Centre > Thales Communications > Unclassified mail > Personal Website: http://www.smtinfo.net > > --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------