Hi Gaby, Both the 'Head-in-Pillow' and the 'Ball-in-Socket' effects have the same root cause—insufficient soldering temperature. In the 'Ball-in-Socket' cases, larger deposited solder paste volumes as well as BGA/PCB warpage exaggerate/heighten the effect. More importantly, in both cases, increasing the soldering temperature solves the problem. Werner --------------------------------------------------- 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 -----------------------------------------------------