| About this Abstract |
| Meeting |
2010 TMS Annual Meeting & Exhibition
|
| Symposium
|
Pb-Free Solders and Emerging Interconnect and Packaging Technologies
|
| Presentation Title |
Effect of Joule Heating on Thermo-Electromigration Induced Failure in Lead-Free Solder |
| Author(s) |
Di Xu, Luhua Xu, Shih-Wei Liang, Stephen Gee, Luu Nguyen, Marshall Andrews, K.N. Tu |
| On-Site Speaker (Planned) |
Di Xu |
| Abstract Scope |
Electromigration tests have been performed on lead-free solders for wafer level chip scale package(WL-CSP). It has been found that under current stressing, joule heating introduces temperature increase in solders and creates a thermal gradient from chip side to substrate side. Electromigration in the solder joints is thus accompanied by thermo-migration. Statistical failure analysis of the combined effect has been studied by multichannel time to failure (TTF) recording and Weibull distribution. By analyzing TTF data for several different current densities and temperatures, we are able to calculate the activation energy (Ea) and the current density exponent (n) in Black’s Mean Time to Failure (MTTF) equation. The effect of joule heating on the increase of temperature has been considered in Black’s equation. It is believed that the joule heating plays an important role in void nucleation and growth process thus has a dominant influence on the value of n. |
| Proceedings Inclusion? |
Planned: Journal of Electronic Materials |