Title :
FEA study of the evolution of wafer warpage during reflow process in WLP
Author :
Chunsheng Zhu ; Wenguo Ning ; Jiaotuo Ye ; Gaowei Xu ; Le Luo
Author_Institution :
Shanghai Inst. of Microsyst. & Inf. Technol., Shanghai, China
Abstract :
In this paper, the evolution of wafer warpage during reflow process in wafer level packaging (WLP) is investigated by finite element analysis (FEA). The investigation focuses on three different fan-in WLP technologies: ball on polymer WLP without under bump metallurgy (UBM), ball on polymer WLP with thick UBM layer and encapsulated copper post WLP. Both wafer-level model and ball-level model are built and the results indicate that wafer warpage derived from ball-level model is compatible with wafer-level model. Ball on polymer WLP with thick UBM layer has the maximum warpage after reflow process. Reflow profiles with different cooling rate are also simulated.
Keywords :
finite element analysis; wafer level packaging; FEA study; UBM layer; ball-level model; ball-on-polymer WLP; cooling rate; encapsulated copper post WLP; fan-in WLP technology; finite element analysis; reflow process; under-bump metallurgy; wafer level packaging; wafer warpage evolution; wafer-level model; Abstracts; Analytical models; Fitting; Semiconductor device modeling; Semiconductor device reliability; Silicon;
Conference_Titel :
Electronic Packaging Technology and High Density Packaging (ICEPT-HDP), 2012 13th International Conference on
Conference_Location :
Guilin
Print_ISBN :
978-1-4673-1682-8
Electronic_ISBN :
978-1-4673-1680-4
DOI :
10.1109/ICEPT-HDP.2012.6474705
