By Topic

Solder joint reliability and characteristics of deformation and crack growth of Sn-Ag-Cu versus eutectic Sn-Pb on a WLP in a thermal cycling test

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

3 Author(s)
Deok-Hoon Kim ; Flip Chip Div., Kulicke & Soffa, Phoenix, AZ, USA ; P. Elenius ; S. Barrett

Sn-Ag-Cu (SAC) is now recognized as the standard lead free solder alloy for packaging interconnect in the electronics industry. This paper analyzes the performance of both SAC and eutectic Sn-Pb solder alloys on Kulicke & Soffa's (K&S') Ultra CSP® wafer level package (WLP) at a thermal cycling (TC) test. The Ultra CSP standard Al/Ni-V/Cu under bump metallurgy (UBM) system was used to analyze if this UBM system with SAC solder would produce acceptable reliability in the TC test. In this study, two TC tests were performed. In the first test, two parts were removed from the TC chamber about every 200 cycles to investigate the characteristics of deformation and crack growth in the SAC and eutectic Sn-Pb Ultra CSP solder joints during TC testing. These TC test results showed that both the SAC and eutectic Sn-Pb Ultra CSPs exhibited normal solder joint fatigue failures during the testing. The SAC Ultra CSP had an equal or 18% higher Weibull life than the eutectic Sn-Pb one. Based on these results it was concluded that the SAC Ultra CSP with the Al/Ni-V/Cu UBM system produces acceptable solder joint reliability in a TC test. The results also revealed that the deformation and crack growth characteristics of the SAC and eutectic Sn-Pb Ultra CSP solder joints were significantly different. The eutectic Sn-Pb solder joints showed significant inelastic shear deformation during the TC testing while the SAC solder joints did not display significant inelastic deformation even at the high temperature regime of the TC test.

Published in:

IEEE Transactions on Electronics Packaging Manufacturing  (Volume:25 ,  Issue: 2 )