Effects of Heat Treatment on the Microstructure and Whisker Growth Propensity of Matte Tin Finish

• 발행기관: 한국마이크로전자및패키징학회
• 저자명: K. S. Kim
• 간행물 정보: 『마이크로전자 및 패키징학회지』제17권 제2호, 11~20쪽, 전체 10쪽
• 주제분류: 공학 > 산업공학
• 파일형태: PDF
• 발행일자: 2010.06.30

영문 초록

The effects of heat treatment on matte pure tin-plated Cu leadframes at high temperature and humidity conditions were investigated. After 1800 hrs of storage at 55℃/85% RH, approximately 14.5 µm long striation-shaped whiskers were observed on the surface of the without postbake treatment (WOPB) samples, while no whiskers were found in with postbake treatment (WPB) samples. The preferred orientations of Sn grains in WOPB and WPB sample did not change after the postbake treatment at 125℃ for 1 hr. However, both changed from (112) to (321) and (101), respectively, after 1800 hrs of storage at 55℃/85% RH. The tensile stress of 8 MPa generated in as-plated sample was changed to a compression stress of 17 MPa after 2 days in room temperature storage. Due to the grain growth during postbake treatment, the WPB samples have more regular grains than the WOPB samples. In the as-plated sample, 0.32 µm thickness of planar intermetallic compound (IMC) was observed. The IMCs in the WOPB and WPB samples had two distinct layers with large grains of Cu₆Sn₅ and with small grains of -Cu₆.₂₆Sn₅.

목차

1. Introduction

2. Experiment

3. Results and Discussion

4. Conclusion

References

키워드

whisker postbake intermetallic compound focused ion beam