학술논문

Correlation between Ag content and Cu pad consumption in lead-free solder joints under electron current stressing
Document Type
Conference
Source
2011 12th International Conference on Electronic Packaging Technology and High Density Packaging Electronic Packaging Technology and High Density Packaging (ICEPT-HDP), 2011 12th International Conference on. :1-5 Aug, 2011
Subject
Components, Circuits, Devices and Systems
Copper
Tin
Electromigration
Soldering
Joints
Reliability
Materials
Ag effect
Sn-Ag-Cu
electromigration
Cu consumption
EBSD
β-Sn orientation
Language
Abstract
White tin (or β-Sn) has a body-center tetragonal (BCT) crystal structure with lattice parameters of a = b = 5.83 Å and c = 3.18 Å. We found that the orientation of the β-Sn phase strongly correlated with the Ag content in the Sn-Ag-Cu solder joints. When the Ag content is equal to or greater than 3 wt.%, the Sn grains display a strong preferred orientation of the c-axes in the direction parallel with the interface (or perpendicular to the electron flow upon current stressing) that substantially reduces the pad consumption induced by electromigration A more detailed analysis through electron backscatter diffraction (EBSD) on the β-Sn grain orientation with respect to the pad consumption is established in this study.