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 | 2009-03-06 15:54:16.0
OSAKA, JAPAN � March 2009 � Nihon Superior Co. Ltd., a supplier of advanced soldering and brazing materials to the global market, announces SN100C high ductility lead-free solder provides high impact strength. A high ductility solder alloy can absorb more energy during impact than an alloy with high tensile strength but is brittle.
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 | 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 | Wed Oct 24 18:08:02 EDT 2001 | davef
1- DF1: WOW!!! How do people get these cool toys? CB: I am with the University at Buffalo Electronic Packaging Lab. http://www.packaging.buffalo.edu We have pretty much everything that is sold on the market as well as Laser inspection technologies we
Electronics Forum | Tue Sep 24 18:38:54 EDT 2019 | researchmfg
Well, there may be a misunderstanding that people think the IMC layer grows the thicker the more strong soldering strength. Actually, the IMC layer can be grown and distributed evenly at the interface between Cu-based, Ni-based and Sn-solder will be
Electronics Forum | Thu Dec 08 07:55:16 EST 2005 | davef
Your understanding of the situation is correct. In both cases, you solder to the nickel. The gold [Au] protects the nickel from oxidation. When soldering, the gold moves into solution in the solder and forms an intermetallic compound [IMC] with th
Electronics Forum | Thu Aug 24 16:44:27 EDT 2000 | Dr. Ning-Cheng Lee
There is no IMC composition can be identified in phase diagram of In/Sn. There are some compositions such as In3Sn or InSn4 cited in earlier literature. Those composition should be regarded as approximate representation of solid solution of In/Sn. I
Electronics Forum | Wed Sep 10 12:56:09 EDT 2003 | davef
Intermetallic compounds [IMC]: * Form during the alloying process of some metals. In soldering these are Sn, Ni, Ag, Cu, Au. * Do not accept solder. * Increase in depth in logarithmic proportion to both time and temperature. [So during the solder
Electronics Forum | Thu Oct 25 16:48:29 EDT 2001 | Cemal Basaran
We can inspect and measure strain field in anything larger than 320nm with Laser techniques we have. We can do this measurements during fatigue testing. Of course thick intermetallic region as a solid region is a problem due to the fact that you ha
