Optimization of Copper Pillar Bump Flip-Chip Package Structure and Materials
| Autor: | Ming-Zheng Huang, 黃明正 |
|---|---|
| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 This work investigated the optimization of copper pillar bump for flip-chip package structure and materials. The test vehicle is 40 nm wafer involved the lead-free copper pillar bump. The finite element method (FEM) was used to analyze the stress of ultra low-k, UBM and copper pillar bump. The design of experimental method was employed to determine the optimal control factors of flip-chip package structure. The critical control factors in this study included diameter of under bump metallurgy (UBM), height of copper pillar, dimension of polyimide opening and underfill materials. To verify the effectiveness of optimal control factors providing for electronic flip-chip packaging industry, the sample was fabrication and verified by reliability tests. Results show that the maximum deformation, the maximum stress, and the maximum stress occurred at the corner which away from the chip center. The optimum combination of process factors in flip-chip package were A2 B3 C3 D1, i.e. diameter of UBM, 90 μm; dimension of polyimide opening, OPI-2 μm; Young’s modulus of underfill, UF5/UF6 GPa, Tg=125 ℃; height of copper pillar bump, HCu-1 μm. The samples of the optimum packaging structure which experienced reliability tests indicated that there is no failure and delamination created in the copper pillar bump, ULK, and UBM. The confirmation tests revealed that the simulation results of FEM was feasible for flip-chip package. The parameter design of the Taguchi method provides an efficient methodology for the optimization of flip-chip package structure and materials. Keywords: Flip-Chip Packages, Finite Element Method, Experimental Design, Ultra-Low K, Copper Pillar Bump |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|