| Title |
Welding & Joining : Study on the Fabrication of Flip Chip Lead - free Solder Bump by Electroplating |
| Authors |
황현(Hyeon Hwang),홍순민(Soon Min Hong),강춘식(Choon Sik Kang),정재필(Jae Pil Jung) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Abstract |
The fabrication of Sn-Pb and Sn-Ag solder bump (150 ㎛ diameter, 250 ㎛ pitch) by electroplating was studied for flip chip package. As a preliminary experiment, the effect of current density and plating time on Sn-Pb and Sn-Ag deposit was investigated. The eutectic compositions of Sn-Pb and Sn-Ag were controlled and the Sn-37 wt.%Pb and Sn-3.5 wt.%Ag solder bumps were fabricated in optimal condition of 6A/d㎡, 4hr and 6A/d㎡, 1.5hr, respectively. The shape of humps was observed by SEM and ball shear test after reflow was performed to measure adhesion strength between solder bump and UBM(Under Bump Metallurgy). The shear strength of Sn-Ag bump fabricated by electroplating was higher than that of Sn-Pb. |