Title :
Flip-Chip Process Using Interlocking-Bump Joints
Author :
Oh, Tae-Sung ; Lee, Kwang-Yong ; Won, Hye-Jin
Author_Institution :
Dept. of Mater. Sci. & Eng., Hongik Univ., Seoul, South Korea
Abstract :
A new flip-chip process using interlocking-bump joints, formed by inserting Cu bumps into Sn bumps, was investigated. Severe plastic deformation of Sn bumps occurred during formation of the interlocking-bump-joint structure. Contact resistance of the interlocking-bump joints was remarkably improved, compared to that of planar-bump joints. The average contact resistances below 17 mOmega/ bump were obtained for the interlocking-bump joints processed with bonding forces larger than 7 N. The interface resistance between a Cu bump and a Sn bump in the interlocking-bump joints processed with a bonding force of 15 N was evaluated as 11.2 mOmega/bump . Chip shear force was greatly improved from 0.14 N of the planar-bump joints up to 3.9 N for the interlocking-bump joints.
Keywords :
bonding processes; copper alloys; flip-chip devices; plastic deformation; tin alloys; CuSn; bonding force; flip-chip process; interlocking-bump joints; interlocking-bump-joint structure formation; plastic deformation; Chip shear force; Cu bump; Sn bump; contact resistance; flip chip; interlocking bump;
Journal_Title :
Components and Packaging Technologies, IEEE Transactions on
DOI :
10.1109/TCAPT.2009.2015594
