Earl & Joseph, I'm not sure what the answer is, but most of the electrolytic Nickel I know of also contain Phosphorus. Perhaps the answer is in a thicker or electrolytic Gold. I'll be interested in the resolution to this one. Regards, Les Connally > From: Earl Moon <[log in to unmask]>, on 7/31/98 8:19 AM: > Joseph, > > I just asked a question concerning phosphorous intermetallic growth as > in item 16 or so. I was prompted to do so because of a response I > received some weeks ago concerning the issue you raise. > > Again, a major BGA supplier (Motorola) wrote me and confided they found > the problem associated with their sphere attachment to a substrate using > the immersion tin and gold processes. To make a long story short, > someone, at some time dropped a board on the floor detaching BGA devices > at all their termination points. > > My question to industry is what can we do to overcome the phosphorous > intermetallic and resulting solder joint embrittlement problem? Can we > go to electroplated nickel in required thicknesses and then deposit > electroless gold over that? > > Earl Moon > > ################################################################ > TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section > for additional information. > For technical support contact Hugo Scaramuzza at [log in to unmask] or > 847-509-9700 ext.312 > ################################################################ > > ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################