Electronics Forum | Fri May 04 16:15:39 EDT 2007 | kazzxtrismus
pillow defect?
Electronics Forum | Sat May 05 08:57:51 EDT 2007 | davef
We agree with Bob R
Electronics Forum | Tue May 01 06:54:22 EDT 2007 | LC
Hi, We are encountering BGA problems where it dislodge from the board. Some are just by normal handling and some are results from drop test about 15 cm high. We have checked our profile and they are in accordance to the BGA recommended reflow profil
Electronics Forum | Tue May 01 09:51:51 EDT 2007 | slthomas
Where are you measuring your temperature at? Are you measuring pad/ball interface temp through a hole in the board, or a lead on a different part, or board surface, or.....?
Electronics Forum | Wed May 02 07:47:21 EDT 2007 | Bob R.
Don't dink with the profile until you have evidence that the profile has something to do with the problem. Step 1 is a cross-section. Where are the joints breaking? Do the joints show signs of proper wetting & intermetallic formation?
Electronics Forum | Wed May 02 12:12:23 EDT 2007 | SWAG
Restrictive carriers or lack of carrier in reflow can cause board warpage = bad for BGA's. Might be something to look at.
Electronics Forum | Thu May 03 10:45:27 EDT 2007 | mmjm_1099
Make sure you check to see that they are not lead-free balling and using leaded profile. We had this and had continous problems. We had to send out our BGA to get reballed.
Electronics Forum | Fri May 04 02:17:48 EDT 2007 | clusogreg
Are you sure the BGA is not Leadfree and the proces you are using is a leaded process? If so then the Balls will not reflow and there will be cracking. Likewise the other way around
Electronics Forum | Fri May 04 12:18:46 EDT 2007 | ck_the_flip
For the mixed alloy scenario, here's something from the fine SMTNet archives: http://www.smtnet.com//forums/index.cfm?fuseaction=view_thread&CFApp=1&Thread_ID=10216&#Message40990
Electronics Forum | Sat May 05 08:00:54 EDT 2007 | davef
Continuing with CF's point on mixed alloy processing of BGA, look here: http://www.aciusa.org/leadfree/LFS_SUMMIT-PDF/09_HILLMAN_Rockwell_Collins_BGA.pdf
