| Title |
Fabrication and Solderability Evaluation of SnBi Coated Sn3.5 wt%Ag Alloy |
| Authors |
이재식(Jae Sik Lee); 방웅호(Woong Ho Bang); 정재필(Jae Pil Jung); 오규환(Kyu Hwan Oh) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Low melting solder; Sn-Bi; Sn-3.5Ag; Electroplating |
| Abstract |
To evaluate the possibility of SnBi coated Sn3.5 wt%Ag solder alloy to be used as low melting temperature solder, 3 different compositions of Sn-Bi layers was electroplated on Sn3,5wt%Ag solders. SnBi coated Sn3.5 wt%Ag rolled solders were bumped on Cu coupons by reflow machine at different temperatures. The microstructures were evaluated with SEM and EPMA, and the compositions of the microstructure were analyzed with EDS. The Sn-Bi coated Sn 3.5 wt%Ag solder was possible to be bonded at low temperature such as 200-250°C. Intermetallic compounds(IMCs) along the bonded interface were well formed at the coated solder composed of high Bi percentage, and IMCs were CuSn_(5), Ag_(3)Sn on the interface. In addition, Cu_(6)Sn_(5) IMCs were formed in solder due to Cu diffusion to the solder. However Bi was not observed on the interface and in solder. (Received December 22, 2003) |