Application of Submodeling Technique to Transient Drop Impact Analysis of Board-level Stacked-Die Package

• Main Authors: Yu-Chia Hsu, 許育嘉
• Other Authors: Hsiang-Chen Hsu
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/78723265134805768208

碩士 === 義守大學 === 機械與自動化工程學系碩士班 === 94 === The objective of this research is to develop a finite element model to predict the board-level dynamic drop test for polymer-based substrate 4-layer stack die packages. The most vulnerable area in BGA package has been found at solder joint when it is subjected to board-level drop test. The lead-free solder material SAC405 (Sn95.5%Ag4.0%Cu0.5%) was used in this research for RoHS regulations and packaging trends. This paper also demonstrates the transient dynamic response for SAC405 solder joint subject to JEDEC drop test standards JESD22 - B111 condition B of 1500 G peak acceleration at 0.5 ms pulse duration. A general purpose finite element software ANSYS using support excitation method was applied to simulate the drop test, and predict the transient dynamic response for 4-layer stack die BGA package. To simplify the 3D drop test board a strip model included solder joints was sliced from full model of package. A submodel scheme was validated with initial coarse model by performing the cut boundary interpolation. Parametric studies were performed for the following cases (1) thickness of compound (2) thickness of BT substrate (3) solder ball height/width at constant volume (4) standard/pyramid stack die (5) number of layers of stack die. The predicted dynamic effects for board-level stack die package are fully studied and summarized as design rule for new system-in-package development.