Reliability studies of surface mount solder joints - Effect of Cu-Sn intermetallic compounds

被引:70
作者
So, ACK
Chan, YC
机构
[1] Department of Electronic Engineering, City University of Hong Kong, Kowloon, Tat Chee Avenue
来源
IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY PART B-ADVANCED PACKAGING | 1996年 / 19卷 / 03期
关键词
D O I
10.1109/96.533909
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
CuSn intermetallic compounds (IMC's), formed at the interface between the solder and the copper substrate are found to play a dominant role in determining the thermal fatigue life of surface mount solder joints fabricated from a conventional infrared reflow process. In order to predict the growth of this IMC layer during the operating life of the solder joint and its effect on the thermal fatigue life, the formation characteristics of the WIC's in 0805 and 1206 LCCC solder joints are systematically studied in this investigation, Only the stable Cu6Sn5% eta-phase intermetallic compound was observed in all as-solidified solder joints as confirmed by scanning electron microscopy (SEM) and energy dispersive x-ray (EDX). The mean layer thickness was found to increase almost linearly with reflow time up to about 200 s. The thickness of the interfacial IMC layer increased with increasing reflow temperature for 0805-type solder joints up to around 250 degrees C and reached a saturated thickness of 2.5 mu m beyond this temperature, Additional intermetallic formation due to higher reflow temperature or longer reflow time would appear as CuSn whiskers in the bulk solder of the joint. The copper land pad size and quality of component lead metallization were also found to greatly affect the formation of CuSn IMC in surface mount solder joints, and hence its reliability in terms of thermal fatigue life and mechanical properties.
引用
收藏
页码:661 / 668
页数:8
相关论文
共 17 条
[1]  
CHAN YC, 1993, P 6 INT S NOND CHAR, P683
[2]  
DIRNFELD SF, 1990, WELDING J OCT, P373
[3]  
FELTON LF, 1991, P MAT DEV MICR PACK, P23
[4]   THE EFFECT OF CU6SN5 WHISKER PRECIPITATES IN BULK 60SN-40PB SOLDER [J].
FREAR, D ;
GRIVAS, D ;
MORRIS, JW .
JOURNAL OF ELECTRONIC MATERIALS, 1987, 16 (03) :181-186
[5]   THE FORMATION OF CU3SN INTERMETALLIC ON THE REACTION OF CU WITH 95PB-5SN SOLDER [J].
GRIVAS, D ;
FREAR, D ;
QUAN, L ;
MORRIS, JW .
JOURNAL OF ELECTRONIC MATERIALS, 1986, 15 (06) :355-359
[6]  
HAIMOVICH J, 1989, WELD J, V68, P102
[7]  
HWANG JS, 1989, SOLDER PASTE ELECT P, P278
[8]  
LAU JH, 1994, HDB FINE PITCH SURFA, P93
[9]  
MANKO HH, 1964, SOLDERS SOLDERING MA, P135
[10]  
MARINIS TF, 1985, P 35 ECTC, P73