HI Paul: Are you sure the paste is what it says it is? It could be a mismarked container of solder paste. Regardless of the type of flux all the paste must reach soldering temperatures to coalesce and form a homogeneous mass of solder to hold the lead. Check the profiles and the time above reflow. Check to see if it is a particular component and what the plating is on the component. If bismuth is around, the melting point of the alloy could be as low as 98 degrees F. So check this out. Finally I would recommend getting some microsections of the affected joints to fully analyze the metallurgy of the metal and see what the physical joint looks like. I hope this helps, good luck Leo Lambert EPTAC Corp www.eptac.com 603-673-7822 ext 15 -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Black, Paul Sent: Thursday, August 21, 2003 6:20 PM To: [log in to unmask] Subject: [TN] Soft solder Has anyone ever run into this issue with solder paste? A year ago, we had some boards with paste that was soft after reflow, to the point that in some cases you could move the leads that were supposedly soldered. The paste manufacturer came in and made some changes to our oven profile, saying that the recipe was not allowing the solder to remain in the liquidus state long enough. We thought the problem was solved but recently had a couple of failed boards returned by a customer and found the problem again. This is a no-clean 63/37 paste. Thank you, Paul Black Manufacturing Engineer Kronos --------------------------------------------------- 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 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 -----------------------------------------------------