Processing strategies for enhanced resistance to impact fracture of thin small-outline packages
The cracking potential of TSOPs (thin small-outline packages) was estimated under impact loading, similar to the process that triggers TSOP fracture during the mold ejection process of plastic-encapsulated microelectronic packaging. It was found that the susceptibility of TSOPs to impact-induced damage is more influenced by the existence of residual stresses than surface defects of the die, which result from the wafer back-lapping process. The experimental results showed that diamond particle-induced crater marks, which contribute to introducing residual stresses to particular sites of the die back surface, can be more critical for determining impact strength of TSOPs than grinding-induced scratch marks. The present work also showed that chemical tempering of the back surface of the die is very effective for suppressing such impact-induced damage of TSOPs under very low impact loads.
Key wordssilicon die TSOP impact test chemical etching defect stress
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- 1.G. Hawkins, H. Berg, M. Mahalingam, and G. Lewis,Proc. 25th Int. Reliability Phys. Symp., p. 216, San Diego, CA, USA (1987).Google Scholar
- 2.T. B. Limm,Proc. 27th Int. Reliability Phys. Symp., p. 131, Phoenix, AZ, USA (1989).Google Scholar
- 5.R. R. Tummala, E. J. Rymaszewski, and A. G. Klopfenstein,Microelectronics Packaging Handbook, p. 101, Van Nostrand Reinhold, New York, USA (1989).Google Scholar
- 6.S. M. Lee, J. H. Lee, S. Y. Oh, and H. K. Chung,Proc. of the 45th IEEE ECTC, p. 455, Las Vegas, NV, USA (1995).Google Scholar