If I understand correctly, you are re-flowing the solder joint a second time (when it goes through the wave solder). Doesn't that raise a concern regarding increased intermetalic layer? > ---------- > From: Jason Gregory[SMTP:[log in to unmask]] > Sent: Sunday, September 24, 2000 6:45 AM > To: [log in to unmask] > Subject: Re: [TN] Bottom Side wave soldering of SMT parts > > Mike, > We print paste and dispense adhesive as a rule. It adds quite a bit of > insurance to the underside of our boards. We have experimented with no > pasting, just wave-soldering. Our yields went down at ICT and open > capacitors went through the roof. We run no-clean for the record. Hope > this > helps. > > Jason Gregory > Manufacturing Supervisor > ACT Manufacturing > Corinth, MS. 38834 > (662)287-3771 x470 > [log in to unmask] > > > -----Original Message----- > > From: Mike Sewell [SMTP:[log in to unmask]] > > Sent: Friday, September 22, 2000 3:39 PM > > To: [log in to unmask] > > Subject: [TN] Bottom Side wave soldering of SMT parts > > > > We build a mixed technology board here with bottom side SMT (SOTs, small > > chips, all laid out not to solder, ie..90 out from each other) and get > > very > > poor yield from wave (chip + lamda) solder. We print the adhesive on, > > P&P, > > cure, stuff, wave then TOUCH UP. My question is: what about printing > > paste, > > dispensing glue (or vice versa), P&P, reflow/cure, stuff, then wave? > Will > > having an existing joint make life easier on wave skips, or will the > wave > > disturb the skipped joints to the point of needing touch up? > > > > Haven't tried it yet because our dispenser is down, > > Mike Sewell > > > > ############################################################## > > TechNet Mail List provided as a free service by IPC using LISTSERV 1.8d > > ############################################################## > > To subscribe/unsubscribe, send a message to [log in to unmask] with > > following text in > > the body: > > To subscribe: SUBSCRIBE TECHNET <your full name> > > To unsubscribe: SIGNOFF TECHNET > > ############################################################## > > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for > > additional > > information. > > If you need assistance - 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 subscribe/unsubscribe, send a message to [log in to unmask] with > following text in > the body: > To subscribe: SUBSCRIBE TECHNET <your full name> > To unsubscribe: SIGNOFF TECHNET > ############################################################## > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for > additional > information. > If you need assistance - 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 subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################