Thermal-mechanical reliability analysis of WLP with fine-pitch copper post bumps
Soldering & Surface Mount Technology
ISSN: 0954-0911
Article publication date: 2 November 2020
Issue publication date: 17 May 2021
Abstract
Purpose
This study aims to investigate the several parameters in wafer-level packaging (WLP) to find the most critical factor impacting the thermal fatigue life, such as the height of copper post, the height of solder bump, the thickness of chip. The FEA results indicate the height of solder bumps is the most important factor in the whole structure.
Design/methodology/approach
The copper post bumps with 65 µm pitch are proposed to investigate the thermal-mechanical performance of WLP. The thermal cycle simulation is used to evaluate the reliability of WLP by using finite element analysis (FEA). Taguchi method is adopted to obtain the sensitivity of parameters of three-dimension finite element model, for an optimized configuration.
Findings
It can be found that the optimal design has increased thermal fatigue life by 147% compared with the original one.
Originality/value
It is concluded that the finite element simulation results show outstanding thermal-mechanical performances of the proposed 65 µm pitch copper post bumps of WLP, including low plastic strain, high thermal fatigue life, which are desired for mobile device.
Keywords
Acknowledgements
This research was funded by the National Natural Science Foundation of China, 61974077 and 61804084.
Citation
Sun, H., Gao, B. and Zhao, J. (2021), "Thermal-mechanical reliability analysis of WLP with fine-pitch copper post bumps", Soldering & Surface Mount Technology, Vol. 33 No. 3, pp. 178-186. https://doi.org/10.1108/SSMT-06-2020-0027
Publisher
:Emerald Publishing Limited
Copyright © 2020, Emerald Publishing Limited