I was not able to open the URL provided. Victor, -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory Sent: Friday, June 12, 2009 1:10 PM To: [log in to unmask] Subject: Re: [TN] Corner ball pad cratering Hi again Genny! Got your pictures posted now. We had quite a severe thunderstorm out here earlier! Sky looked like it was night with an eery greenish tint to it, had some 60-mph straight line winds and just to the west of us in a town called Stillwater they had baseball sized hail! Several hundred cars were damaged from what I heard on the radio! Thanks goodness the hail missed us! What were we talking about? Oh yeah, your pictures ;^) go to: http://stevezeva.homestead.com/files/Cross-Section_laminate_crack_bright 100x.jpg http://stevezeva.homestead.com/files/Cross-Section_laminate_crack_bright 200x.jpg Steve -----Original Message----- From: Genny Gibbard [mailto:[log in to unmask]] Sent: Friday, June 12, 2009 11:12 AM To: Steve Gregory; TechNet E-Mail Forum Subject: RE: [TN] Corner ball pad cratering As always, Steve, you are a wealth of information. That article is perfect, thank you. This seems to mirror what Amol said about doing a 1/4 of the length. This article said to do an L shaped bead 2-6 balls along each corner side. Here are some photos to post. Would you oblige? BGA is 40mm per side. PCB is ~1 ft sq. A little bigger than what is found in the typical blackberry, I think... Ball pitch is 1.27mm. We believe the cause is mechanical, not thermal. Thanks everyone. Genny -----Original Message----- From: Steve Gregory [mailto:[log in to unmask]] Sent: June 12, 2009 6:35 AM To: TechNet E-Mail Forum; Genny Gibbard Subject: RE: [TN] Corner ball pad cratering Morning Genny, Since you said you were going to look at corner bonding, here is a really good article (if you haven't seen it already) that Michael Kochanowski from Intel and Brian Toleno from Henkel did about it: http://www.trafalgar2.com/documents/Technical_Articles/6.09-kochanowski. pdf Steve -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Genny Gibbard Sent: Thursday, June 11, 2009 3:10 PM To: [log in to unmask] Subject: [TN] Corner ball pad cratering Hello all, If you have identified a BGA with corner ball pad cratering, what would be your suggestions to correct this condition? Our thoughts: 1. We plan to evaluate our handling processes to reduce/remove excessive flex/strain occurring around this part 2. We plan to evaluate corner bonding or underfilling for the BGA. Which do you feel would be the best direction to go? Do you have other suggestions? Thanks in advance for all your help Genny --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------