Microstructural Study of Creep-Fatigue Crack Propagation for Sn-3.0Ag-0.5Cu Lead-Free Solder

• 발행기관: 한국마이크로전자및패키징학회
• 간행물 정보: 『마이크로전자 및 패키징학회지』제17권 제3호, 33~41쪽, 전체 9쪽
• 주제분류: 공학 > 산업공학
• 파일형태: PDF
• 발행일자: 2010.09.30

영문 초록

Crack propagation mechanisms of Sn-3.0Ag-0.5Cu solder were studied in strain controlled push-pull creep-fatigue conditions using the fast-fast (pp) and the slow-fast (cp) strain waveforms at 313 K. Transgranular cracking was found in the pp strain waveform which led to the cycle-dominant crack propagation and intergranular cracking in the cp strain waveform that led to the time-dominant crack propagation. The time-dominant crack propagation rate was faster than the cycle-dominant crack propagation rate when compared with J-integral range which resulted from the creep damage at the crack tip in the cp strain waveform. Clear recrystallization around the crack was found in the pp and the cp strain waveforms, but the recrystallized grain size in the cp strain waveform was smaller than that in the pp strain waveform. The cycle-dominant crack propagated in the normal direction to the specimen axis macroscopically, but the time-dominant crack propagated in the shear direction which was discussed in relation with shear micro cracks formed at the crack tip.

목차

1. Introduction

2. Experimental Procedure

3. Results and Discussion

4. Conclusions

References

키워드

Crack propagation Fracture mechanism Micro crack Recrystallization Lead-free solder