Flip chip metallurgies for lead-free solders

被引：5

作者：

Korhonen, TM ^{[1
]}

Hong, SJ ^{[1
]}

Korhonen, MA ^{[1
]}

Li, CY ^{[1
]}

机构：

[1] Cornell Univ, Dept Mat Sci & Engn, Ithaca, NY 14853 USA

来源：

ELECTRONIC PACKAGING MATERIALS SCIENCE X | 1998年 / 515卷

关键词：

D O I：

10.1557/PROC-515-79

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

The most commonly used lead-free solders contain large amounts of tin, which makes them incompatible with the conventional Cu-based underbump metallization (UBM) schemes. The tin in the solder reacts with the copper layer of the UBM, depleting the UBM of copper and causing loss of adhesion and a weak interface. Use of new under bump metallization schemes with Ni or CuNi alloys as the solderable layer were investigated in this study. Instead of Cr, a Ti-based adhesion layer was used to decrease the amount of stress in the CuNi layer. Flip chip solder joints were made in which three Sn-Bi-Ag based lead-free solders were reflowed to several UBM pads of different compositions. The resulting interfacial microstructures were examined by SEM/EDX analysis of cross-sectioned samples. The joints were also mechanically tested in fatigue and shear to assess the quality and reliability of the interface.

引用

页码：79 / 83

页数：5