Technical Library | 2013-01-03 20:27:54.0
Electronics assemblies with large flip-chip BGA packages can be prone to either pad cratering or brittle intermetallic (IMC) failures under excessive PCB bending. Pad cratering cracks are not detected by electrical testing or non-destructive inspection methods, yet they pose a long term reliability risk since the cracks may propagate under subsequent loads to cause electrical failure. Since the initiation of pad cratering does not result in an instantaneous electrical signature, detecting the onset of this failure has been challenging. An acoustic emission methodology was recently developed by the authors to detect the onset of pad cratering. The instantaneous release of elastic energy associated with the initiation of an internal crack, i.e., Acoustic Emission (AE), can be monitored to accurately determine the onset of both pad cratering and brittle intermetallic (IMC) failures.
Industry News | 2009-07-28 11:43:13.0
OSAKA, JAPAN — July 2009 — Nihon Superior Co. Ltd., a supplier of advanced soldering and brazing materials to the global market, announces that a new presentation about the challenges and issues in lead-free soldering is now available on the company’s Web site.
Electronics Forum | Tue Jul 14 07:23:50 EDT 2020 | researchmfg
There is a misunderstanding that people think the IMC layer grows the thicker the stronger soldering strength. The IMC layer can be grown and distributed evenly at the interface location will be good enough. Once the IMC layer grows too thick and ove
Electronics Forum | Mon Feb 21 21:28:13 EST 2005 | abhirami
Davef, We see increased IMC thickness for electroless Ni and the brittle mode failure occurs much earlier in multiple reflows, exposing IMC layers. Not good for board level reliability.Regards. GV
Electronics Forum | Wed May 24 16:40:40 EDT 2006 | samir
Yikes! Sounds like a hairy situation there. I've successfully collapsed a Pb-Free BGA (using a Sn/Pb solder paste), with a peak temperature of 220 Deg. C and Time Above SAC's Eutetic point (217) of 17 seconds. Beware of overcooking your smaller ma
Electronics Forum | Sun Mar 31 00:42:09 EDT 2013 | dhanish
Why we cannot run Pb Free BGA with Sn/Pb process but we can run high temp BGA(90/10) with Sn/Pb? Both require high temperature to form the IMC.Why there is a difference in the reliability?
Electronics Forum | Sat Aug 22 05:19:42 EDT 2009 | ghepo
Dear Eric, in my opinion this is a very complex problem, that require to know many details for answer. For example : 1) what about the PCB finishing ? Have you verify the quality of they ? 2) what about the solder paste (the exactly composition)? 3)
Electronics Forum | Mon Aug 24 13:12:28 EDT 2009 | ghepo
OK Eric, maybe you're right. My suggestion is to proceed by exclusion. First perform the tape test. Is easy and without costs. You have used many similar PCB without problem, but from the same vendor ? Is my experience that in similar cases the qua
Electronics Forum | Thu Jan 15 09:40:47 EST 2004 | davef
Search the fine SMTnet Archives. For instance: http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=24429 Do not get your hopes up about finding something to support your "leaching out of silver theory", though. * AgxSn IMC are disbursed ro
Electronics Forum | Mon Feb 21 09:05:46 EST 2005 | davef
We're try to stay away from using electroless nickel. Please describe the differences between the IMC.
