Hi all, will send a picture to Steve for getting help. Thermosonic 25um gold balls don't stick to the thinfilm gold on a optic chip. 2,500A Au over 400A Cr. Bad yield, many balls lift. No contaminations found. Despite I have the good fishbone, I can't find out why the odd pattern under lifted bals. A guess is that the capillary have to steep chamfer angle, so that the U/S mechanical energy becomes concentrated in the middle. Anyone with similar experience? Inge --------------------------------------------------- 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 -----------------------------------------------------