Curious what criteria are you using for BGA underfill (i.e. voiding, coverage, etc). IPC-7095B section 7.2.2? -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Joe Macko Sent: Wednesday, October 31, 2007 7:34 PM To: [log in to unmask] Subject: [TN] verifying BGA underfill coverage Fellow Techs We purchased a GPD automated epoxy dispenser and I want to proof out the new automated underfill application process on BGAs. We use a wickable Loctite underfill that requires an elevated temperature to flow properly under BGAs, etc.. Currently we successfully underfill by hand and want to switch to an automated process using the GPD. I want to verify the underfill coverage under BGAs using a non-destructive test method. The only non-destructive method I am aware of is acoustic imaging using an instrument such as Sonoscan, which I believe will show voids in the underfill material. I do not know how industry non-destructively verifies underfill coverage. I plan on physically removing some BGAs on scrap boards to verify coverage but do not want to do this on good boards for obvious reasons. Question - What is the commonly accepted non-destructive method for verifying BGA underfill coverage? Look forward to your comment. thanks Best Regards, - Joe --------------------------------------------------- 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 -----------------------------------------------------