I couldn't have said it any better, maybe with a little more whit, but not any better technically. Just like cookies at X-mas, we all have our melting moments. Dewey -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Werner Engelmaier /* Sent: Monday, January 07, 2008 9:56 AM To: [log in to unmask] Subject: Re: [TN] Reflow profile development - correct starting temperature for evaluating TAL using non-eutectic solders Hi Joe, Unfortunately, a natural outcome of a proper reflow profile has become a parameter to be aimed at. TAL is NOT a proper reflow parameter, and assures in and of itself not good wetting and metallurgical bonding. Adequate solder joint quality is assured with achieving Liquidus+20 C for 5 seconds at the slowest heating solder joint in the assembly. So whatever the Liquidus temperature is for your solder alloy +20 for 5 seconds. For eutectic SnPb that means 203C for 5 seconds at the slowest heating solder joint, which of course means everything else on the assembly will see higher peak temperatures for longer times [except for vapor phase, of course]. Regards, Werner Engelmaier Engelmaier Associates, L.C. Electronic Packaging, Interconnection and Reliability Consulting 7 Jasmine Run Ormond Beach, FL 32174 USA Phone: 386-437-8747, Cell: 386-316-5904 E-mail: [log in to unmask], Website: www.engelmaier.com ************** Start the year off right. Easy ways to stay in shape. http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489 --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 -----------------------------------------------------