Electronics Forum | Mon Nov 27 08:05:50 EST 2006 | davef
There is no standard for a strain gage measurement of allowable deflection of a board or a fixture. It's possible that your fixture is causing the BGA cracking that you see. What protion of the BGA is cracking? If it is the solder connection, sear
Electronics Forum | Mon May 16 22:59:40 EDT 2005 | davef
We believe your problem is caused by the mismatch in CTE of the material ised in your BGA. In fact, this "potato chipping" [where the corners curl-up] is present in all BGA. The issue is the matter of degree. [Mismatching CTE is how old thermostats
Electronics Forum | Fri Jun 20 14:35:29 EDT 2008 | mumtaz
try changint the pickle to a potatoe! Remeber that post? Honda guy thought it was real!
Electronics Forum | Tue Jun 25 01:24:25 EDT 2019 | sssamw
That is possibley CTE mismatch between QFN and PCB material, the thicker PCB the higher fail rate.
Electronics Forum | Wed Jul 26 18:23:47 EDT 2000 | Gary
I have been following forum discussions here and eslewhere, attended technical sessions at APEX and have been experimenting with the paste-in-hole process on some of our new product. I have run into one problem I have never seen mentioned, that is a
Electronics Forum | Thu Jul 27 21:34:41 EDT 2000 | Dave F
Gary: That's curious. Tell us more about your process steps, temperature profiles, paste, warping of the board without the PIH processing, components, etc
Electronics Forum | Fri Jul 28 14:34:13 EDT 2000 | Gary Simbulan
Belive it or not, these boards were run through a Centech batch mode Vapor Phase machine. Single stage top side IR preheat. Vapor temp 218 C. Solder paste is an SN62 RMA.The boards were FR4 8 layer w/ solder mask, fairly conventional as might be e
Electronics Forum | Thu Sep 07 15:24:29 EDT 2000 | Murad Kurwa
Steven, Try http://www.document-center.com/home. You will find various standards for BGAs freely-available but not for free. BTW, I have never seen a BGA underfilled. Only FC and CSPs. The standards available will explain when to.....High CTE delta
Electronics Forum | Thu Apr 05 08:44:45 EDT 2007 | ck_the_flip
"Guest" is right, actually. CSP's are essentially BGA's, but typically the pitch and ball diameters are much smaller and in some cases, the pads of the CSP's can not be screen printed. If that's the case, you'd have to have flux-dip capabilities on
Electronics Forum | Wed Dec 05 17:12:13 EST 2012 | davef
Yes, we're all amazed when the nightly news announcer requests that we call the crime fighters hotline to ID the perp [closely resembling a garbage bag filled with potatoes] that was 'taped' on such high quality video while pistol-whipping a clerk at
