Peter, the problem could actually be with the components, rather than the boards. I had a problem with blow holes resulting from additives used by the component manufacturers to ensure the leads appeared bright and shiny. A quick way to see if this is the problem is to reflow the coating on leads with a soldering iron under a microscope. If it bubbles like Alka-Selzer in a glass of water, the components may be the source of your blow holes. Good luck, Terri > ---------- > From: Busko, Wolfgang[SMTP:[log in to unmask]] > Reply To: TechNet E-Mail Forum. > Sent: Thursday, November 01, 2001 11:00 AM > To: [log in to unmask] > Subject: [TN] AW: [TN] Blow holes in solder joints > > 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 > -------------------------------------------------------------------------- > ------- > --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------