Hi Bev & All, I do not know why nobody responded to my e-mail. I said: "Just like George, I am struggling getting an understanding of you problem. To me, 'head-on-pillow' solder defects are almost always caused by insufficient peak temperature. If these HOP's occurred essentially near the center of the BGA, you have your answer, If the HOP's are distributed over the whole array, than the root cause is not insufficient peak temperature unless the whole reflow process is too low." I am still betting on insufficient peak temperature. HOP implies a large pasty range; thus your solder(s) are not near eutectic. Whatever alloy they actually are, the insufficient peak temperature was too low to get them fully liquid to join up. Werner ************** 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 -----------------------------------------------------