Any amount of lead over about 1% will start reducing the melting point to about 183 C. So, if after you have formed the solder joint and it contains more than the above amount of lead, your melting point will be about 183 C. Just like 63/37. Reliability depends upon what you are worried about. Parts falling off the board when the solder joint reaches 183 C maybe? Donald Kyle At 09:07 AM 4/11/2005, you wrote: >Does anyone think that 3.5% Pb in a SN96AG4 (aka Pb-free) is abnormal? I >think it is, but I have doubters here. This was measured by EDX. > >Does anyone have any evidence what this does to reliability? >Specifically mechanical cycling. > >Paul Stolar >Materials/Reliability Engineer >Manufacturing Reliability Lead Engineer >Baker Atlas >713-625-5376 > >--------------------------------------------------- >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 >847-615-7100 ext.2815 >----------------------------------------------------- Donald Kyle C.I.D.+ 281-285-7528 voice 281-285-8593 fax [log in to unmask] Schlumberger Sugar Land Product Center (SPC) Mail Drop MD155-1 155 Industrial Boulevard Sugar Land, Texas 77478 --------------------------------------------------- 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 847-615-7100 ext.2815 -----------------------------------------------------