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

fYear

2012

fDate

13-16 Aug. 2012

Firstpage

661

Lastpage

665

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;

fLanguage

English

Publisher

ieee

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

Type

conf

DOI

10.1109/ICEPT-HDP.2012.6474705

Filename

6474705