Title :
Study on the interfaces between copper alloys for lead frame and Sn-Pb solder alloys
Author :
Qian, Wang ; Lee, Shi-Wei Ricky ; Yuwen, Cao ; Jusheng, Ma
Author_Institution :
Dept. of Mater. Sci. & Eng., Tsinghua Univ., Beijing, China
Abstract :
The reliability of solder joints is deeply affected by microelements in solder or matrix materials. The microstructures and their changes under high temperature aging of the interfaces between four civil copper alloys for lead frames and Sn-Pb eutectic solder are investigated. It is found that the Zn element in copper alloys influences the intermetallic compound layers, because Zn blocks the diffusion of Cu and Sn atoms through the interfaces and the increase of the thickness of Cu-Sn intermetallic compound layers slows down. As a result, the fatigue resistance of solder joints is improved
Keywords :
ageing; assembling; chemical interdiffusion; circuit reliability; copper alloys; crystal microstructure; diffusion barriers; fatigue; interface structure; iron alloys; lead alloys; nickel alloys; packaging; phosphorus alloys; printed circuit manufacture; silicon alloys; tin alloys; zinc alloys; Cu alloy lead frame/Sn-Pb solder alloy interfaces; Cu diffusion; Cu-Sn intermetallic compound layer thickness; CuFeP-SnPb; CuNiSiZn-SnPb; CuZnFePSn-SnPb; Sn diffusion; Sn-Pb eutectic solder; Zn diffusion blocking; Zn element; civil copper alloys; copper alloys; fatigue resistance; high temperature aging; intermetallic compound layers; lead frames; matrix materials; microelements; microstructures; reliability; solder joints; solder materials; Aging; Copper alloys; Intermetallic; Joining materials; Lead; Materials reliability; Microstructure; Soldering; Temperature; Zinc;
Conference_Titel :
Electronic Materials and Packaging, 2000. (EMAP 2000). International Symposium on
Conference_Location :
Hong Kong
Print_ISBN :
0-7803-6654-9
DOI :
10.1109/EMAP.2000.904185
