Werner, I must disagree with you here. I think in many cases the IPC committees DO have authorities and I would feel more comfortable with the consensus of one of those groups than other groups I can think of. Is the consensus opinion published always the best, most correct approach? No, but that is an artifact of the democratic process, and there is always the pathway that if you have the data, you can usually sway the consensus opinion. Unless we want to adopt an autocratic approach, which would scare the begeezus out of me, tis the nature of the animal. Doug Pauls Rockwell Collins Werner Engelmaier /* <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 04/15/2009 04:44 PM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to [log in to unmask] To [log in to unmask] cc Subject Re: [TN] Gold/Tin Intermetallics, why are we afraid? Joyce, Since when are committees 'authorities'? You get the lowest common denominator and that frequently and surprisingly is pretty good, but authority?no way. Werner -----Original Message----- From: Joyce Koo <[log in to unmask]> To: [log in to unmask] Sent: Wed, 15 Apr 2009 5:33 pm Subject: Re: [TN] Gold/Tin Intermetallics, why are we afraid? I am not the one to judge. Ipc is the authority. -------------------------- Sent using BlackBerry ----- Original Message ----- From: Wenger, George M. <[log in to unmask]> To: TechNet E-Mail Forum <[log in to unmask]>; Joyce Koo Sent: Wed Apr 15 17:31:10 2009 Subject: RE: [TN] Gold/Tin Intermetallics, why are we afraid? Joyce, If ImAg is not recommended for IPC-6010 Class 3 what surface finishes are? Regards, George George M. Wenger Andrew Wireless Solutions Senior Principal FMA / Reliability Engineer 40 Technology Drive, Warren, NJ 07059 (908) 546-4531 [Office] (732) 309-8964 [Cell] [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Joyce Koo Sent: Wednesday, April 15, 2009 5:11 PM To: [log in to unmask] Subject: Re: [TN] Gold/Tin Intermetallics, why are we afraid? "ImAG finishes have a 12-month shelf life in a controlled environment (<35[degrees]C/<85[degrees] RH), which can be significantly shortened when exposed to air pollution with high sulfur and chlorine content. Silver embrittlement Embrittlement A general set of phenomena whereby materials suffer a marked decrease in their ability to deform=2 0(loss of ductility) or in their ability to absorb energy during fracture (loss of toughness), with little change in other mechanical properties, such ([Ag.sub.3]Sn intermetallics) of solder joints may occur when the finish thickness exceeds IPC-4553 recommendations and Pb-free, high silver content solders are used. ImAG is not recommended for high-reliability assemblies that must meet IPC-6010 Class 3 requirements, but is acceptable for Classes 1 and 2." http://www.thefreelibrary.com/Will+discoloration+tarnish+ImAg+reliabilit y%3F+Watch+for+silver...-a0193896272 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Werner Engelmaier /* Sent: Wednesday, April 15, 2009 4:34 PM To: [log in to unmask] Subject: Re: [TN] Gold/Tin Intermetallics, why are we afraid? Hi Vlad, I cannot comment on your specific case, but look at the pics below to see Ag-embrittlement. Sorry 'Netters, IPC strips pics. 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