With electronic packaging towards the development of lead free process, the research on the portable electronic devices subject to impact load is emphasized gradually. At present, for drop test and cyclic bending test, most of the failure modes lie on the modes of "fracturing in IMC layer" or "fracturing on IMC/solder boundary". The purpose of this work is to use 3D numerical analysis software ANSYS/LS_DYNA, that were found out a proper numerical model, to further analyze the impact fracture of lead-free solder.
From the numerical results, the strain rate of solder joint ranges from 103 s-1 to 104 s-1 under an impact velocity of 2 m/s. At this strain rate, the mechanical properties of solder joint could be effectively investigated. When IMC strength is smaller than 300MPa, the main failure mode is fracturing of IMC; whilst, IMC strength is greater than 300MPa, the failure mode becomes fracturing of bulk solder, but the failure mode of fracturing of IMC and a partial solder requires a model with more fine meshes to simulate. Different velocities did not affect the numerical results significantly, because the material parameters of a solder ball is strongly dependent on strain rate. Also, we found that the impact test in reality does not present a shear-dominant mode alone even when the impact angle is 0¢X. While using simulation to carry out the dynamic experiment, it can be observed that the course of solder joint suffering the damage provides a good reference and contrast for the experimental work in the future.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0826105-144803 |
| Date | 26 August 2005 |
| Creators | Li, Bo-Yu |
| Contributors | Yi-Shao Lai, Ming Chen, Chorng-Fuh Liu, Ming-Hwa R. Jen |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0826105-144803 |
| Rights | not_available, Copyright information available at source archive |
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