Concur with Ed ; one of pretin's main function is washing out as much gold as possible . If I could recoment one of the DIP rework solder fountains (sometimes called miniwaves): keeps dross out ; washes in continuous stream . Don't make a mistake of mixing that solder ever to your main solder wave ; or use it for anything else but washing or desoldering (soldering would give you seriously contaminated joints). Paul Klasek ResMed -----Original Message----- From: Edward Hare, <SEM Lab, Inc.> [mailto:[log in to unmask]] Sent: Wednesday, 1 September 1999 0:30 To: [log in to unmask] Subject: Re: [TN] Pre-tinning gold leads Nick, In my opinion pretinning of gold plated leads is important to (1) prevent gold embrittlement of the solder joint and (2) determine if the leads are solderable prior to assembly (i.e. gold can be plated over oxidized nickel). I've seen several instances of gold imbrittlement associated with soldering to gold plated leads and gold thick film pads. The volume fraction of brittle AuSn4 intermetallics tend to be high due to the 4:1 ration of Sn to Au in the intermetallic compound. You might want to check into John Lau's book, "Solder Joint Reliability", Van Nostrand Reinhold, pp. 205 - 212. Regards, Ed Hare SEM Lab, Inc. [log in to unmask] Nick D'Onofrio wrote: > We are pre-tinning the gold leads prior to assembly on our military > products. I'm looking for some constructive data or argument to decide if we > should continue this practice. > My concern would be gold embrittlement in the solder joint and any latent > failures attributed to this. > Any comments or guidance in this matter would appreciated. > > Regards, > Nick D. > > ############################################################## > TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c > ############################################################## > 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 Gayatri Sardeshpande at [log in to unmask] or > 847-509-9700 ext.5365 > ############################################################## ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## 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 Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ############################################################## ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## 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 Gayatri Sardeshpande at [log in to unmask] or 847-509-9700 ext.5365 ##############################################################