Investigations on the mechanism of microweld changes during ultrasonic wire bonding by molecular dynamics simulation
Investigations on the mechanism of microweld changes during ultrasonic wire bonding by molecular dynamics simulation
复制标题
DOI：
10.1016/j.matdes.2020.108718
复制
发表时间：
2020-07-01
影响因子：
8.4
通讯作者：
Twiefel, Jens
中科院分区：
文献类型：
--
作者：
Long, Yangyang;He, Bo;Twiefel, Jens
尽管超声引线键合技术和其他超声金属连接技术得到了广泛而长期的应用，但由于实验研究的困难，对键合过程中微焊缝的形成、变形和断裂等机理的研究还很少。在这项工作中，这一机制下不同的表面形貌和位移模式进行了研究，通过分子动力学模拟。发现微焊缝可以瞬间形成或断裂。由于局部导线部分和局部基底部分之间的相对运动，微焊缝可能会发生很大的变形甚至断裂。通过对剪切应力和等效结合面积的定量分析，研究了材料、表面形貌、靠近距离和振动幅度对微焊缝变化的影响。结果表明，这四个因素对最终连接和界面结构有重要影响。对微焊缝变化的尺度分析表明，小尺度下的模拟结果能够代表大尺度下的模拟结果，接近常用的表面粗糙度范围。这种对微焊缝变化的更深入理解导致更好的控制策略和键合过程的增强。(C)2020年，任作家。爱思唯尔有限公司出版
Despite the wide and long-term applications of ultrasonic (US) wire bonding and other US metal joining technol-ogies, the mechanism of microweld changes during the bonding process, including formation, deformation and breakage, is rarely known as it is very dif ficult to be investigated by experiments. In this work, this mechanism under different surface topographies and displacement patterns is studied by molecular dynamics simulation. It is found that microwelds can be formed or broken instantly. Due to the relative motion between the local wire part and the local substrate part, microwelds can be largely deformed or even broken. The impacts of mate-rial, surface topography, approaching distance and vibration amplitude on the microweld changes are investi-gated via the quanti fication of the shear stress and the equivalent bonded area. It is shown that these four factors signi ficantly in fluence the final connection and the interface structure. The analysis of the scale in fluence on the microweld changes shows that the simulation results at a small-scale are able to represent those at a large-scale which is close to the range of the commonly used surface roughness. This deeper understanding on the microweld changes leads to a better control strategy and an enhancement of the bonding process. (C) 2020 The Authors. Published by Elsevier Ltd.