Even galvanic corrosion may (not say is) not be a problem, fretting corrosion should be a concern. http://www.amp.com/products/technology/articles/dd68_1.stm If the force is very high (stress) and on/off is not that often, you may (not say are) worry about cat whiskers (zinc).... If you are un-lucky, you may have "fur coat" instead...Dave is going to tell me he filled up nitrogen, argon in the package... I guess...;-( jk >-----Original Message----- >From: TechNet [mailto:[log in to unmask]] On Behalf Of Dave Hillman >Sent: Thursday, September 11, 2003 12:36 PM >To: [log in to unmask] >Subject: Re: [TN] Zinc Plating Finish > > >Hi TechNet! Steve - you have fallen into the galvanic series >trap! There is the potential for a galvanic reaction between >Zn and Sn but there are several other factors which need to be >considered - the Galvanic Series chart is only a first order >approximation of a possible reaction. Your cathode-to-anode >ration, the type/use of coatings (postcoat, chem film), the >"chemistry" of the use environment, and how "sealed" the >electronic assembly is designed all play a role in the amount >and type of corrosive attack on the Zn plating. There will be >a paper at the IPC Fall meeting on the subject of galvanic >compatibility of the new immersion finishes and aluminum which >may be helpful. > >Dave Hillman >Rockwell Collins >[log in to unmask] > > > > > Steve Gregory > <[log in to unmask] To: >[log in to unmask] > m> cc: > Sent by: TechNet Subject: Re: >[TN] Zinc Plating Finish > <[log in to unmask]> > > > 09/11/2003 11:16 > AM > Please respond to > "TechNet E-Mail > Forum."; Please > respond to > SteveZeva > > > > > > >Hi Victor! > >What will probably happen is that the Zinc will start to >corrode because of the galvanic action between itself and the >tin, or tin / lead. Go to: > >http://www.ccfast.com/ccfcorrosion.html > >There you will see a Galvanic Series chart, and a simple >explaination about Galvanic action. Zinc, and Tin or Tin / >Lead isn't all that far apart in the chart, but far enough >that the Zinc will corrode. > >-Steve Gregory- > > > Fellow TechNetters: > > What are the exposures of having or selecting a ZINC >plating finish for an ELECTRICAL CONTACT such as a solder less > crimp connector and straight pin connector. What can occur if these > finishes are mixed mated with a SnPb or Sn finish surface. > > Victor, > > > >--------------------------------------------------- >Technet Mail List provided as a free service by IPC using >LISTSERV 1.8e 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 or >(re-start) delivery of Technet send e-mail to >[log in to unmask]: SET Technet NOMAIL or (MAIL) >To receive ONE mailing per day of all the posts: send e-mail to >[log in to unmask]: SET Technet Digest >Search the archives of previous posts at: >http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------