| Summary: | 碩士 === 義守大學 === 機械與自動化工程學系碩士班 === 98 === The wire bonding process has been widely used in the semiconductor package industry for the past two decades for its easy application and low cost. However, the mechanism of dynamic response for wire bonding process is scarcely reported due to the material data is difficultly to determine. As the price of gold is dramatically increasing in the year of 2009, engineers and researchers have been focused on the replacement material of copper wire.
In order to reduce the cost, we use copper wire in substitution for gold wire.Copper wire has better electrical conductivity and thermal conductivity than gold wire, but copper wire is oxidation easily and material strength is higher than gold wire. It maybe brings aluminum pad squeeze (excessive plastic deformation) because material strength of copper wire is high. This research involves in three parts: the first is we etching copper wire and use SEM to see the grain. Secondary, Atomic Force Microscopy (AFM) is applied to measure interfacial frictional coefficient and the surface roughness, and we take the data into ANSYS to simulate. In the third, numerical prediction for wire bonding process is conducted based on commercial finite element software of ANSYS/LS-DYNA. In this research, we take our attention in aluminum pad squeeze, so we use metallography experiment to understand the grain become big and the material strength is lower. It is noted that the material of bond pad should be Al pad instead pure Al pad. Special emphasizes are focused on the via layouts and the optimal design of microstructure beneath the bond pad. A series of comprehensive parametric studies were conducted in this research.
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