Wu, Hui-MinHui-MinWuWu, Feng-ChihFeng-ChihWuChuang, Tung-HanTung-HanChuang2009-01-062018-06-282009-01-062018-06-28200503615235http://ntur.lib.ntu.edu.tw//handle/246246/95948https://www.scopus.com/inward/record.uri?eid=2-s2.0-28044431652&doi=10.1007%2fs11664-005-0195-1&partnerID=40&md5=0669bd90f64f94b7cf7eb51b836dfc8dThe intermetallic compounds formed during the reflow and aging of Sn-20In-2.8Ag ball-grid-array (BGA) packages are investigated. After reflow, a large number of cubic-shaped AuIn2 intermetallics accompanied by Ag2In precipitates appear in the solder matrix, while a Ni(Sn 0.72Ni0.28)2 intermetallic layer is formed at the solder/pad interface. With further aging at 100°C, many voids can be observed in the solder matrix and at the solder/pad interface. The continuous distribution of voids at the interface of specimens after prolonged aging at 100°C causes their bonding strength to decrease from 5.03 N (as reflowed) to about 3.50 N. Aging at 150°C induces many column-shaped (Cu 0.74Ni0.26)6(Sn0.92In 0.08)5 intermetallic compounds to grow rapidly and expand from the solder/pad interface into the solder matrix. The high microhardness of these intermetallic columns causes the bonding strength of the Sn-20In-2.8Ag BGA solder joints to increase to 5.68 N after aging at 150°C for 500 h.application/pdf749147 bytesapplication/pdfen-USBall shear strength; Ball-grid-array (BGA); Intermetallic compounds; Sn-20In-2.8Ag solderCopper; Gold; Microhardness; Nickel; Precipitation (chemical); Soldered joints; Soldering alloys; Temperature distribution; Tin; Ball shear strength; Ball-grid array (BGA); Sn-20In-2.8Ag solder; Intermetallicsjournal article2-s2.0-28044431652http://ntur.lib.ntu.edu.tw/bitstream/246246/95948/1/90.pdf