Peter, an easy, fast check for outgassing would be using some oil that can withstand the temperature and has of course no water-content, apply it to a through hole and heat the barrel with a solder iron. Best done under a microscope for better visibility. You should not see any bubbles from outgassing. Haven´t done it myself but still remember that advice given here or on SMTnet a while ago and connect it somehow with Earl, The Moonman, but don´t nail me for that one. I´m not sure if baking those boards will bring any relief. Good luck Wolfgang -----Ursprüngliche Nachricht----- Von: PL [mailto:[log in to unmask]] Gesendet am: Donnerstag, 1. November 2001 07:50 An: [log in to unmask] Betreff: [TN] Blow holes in solder joints Hello, I would like to ask your input on trouble shooting a wave soldering process that I've encountered producing blow holes on the PCA. The blow holes were seen at random locations, mostly on small and light caps. The boards were manufactured in recent weeks. Some board warppage was noticed after the wave. Things I tried: - Boards from a different manufactured date, no effect - Turned on turbulence wave. It reduced but didn't completely eliminate the defect - used stiffener on board edge to reduce board sagging - used dummy weights on top of parts seen having defect to minimize "dancing" during wave How critical is the component lead-to-hole ratio as far as its impact on solder joint quality? Could anyone explain how a blow hole can occur and possible steps taken to eliminate the defect? Rgds, Peter _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com ---------------------------------------------------------------------------- ----- 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 the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- 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 the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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 ---------------------------------------------------------------------------------