Microstructural evolution of ultrasonic-bonded aluminum wires
Microstructural evolution of ultrasonic-bonded aluminum wires
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DOI：
10.1016/j.microrel.2015.03.002
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发表时间：
2015-05-01
影响因子：
1.6
通讯作者：
Lang, Klaus Dieter
中科院分区：
文献类型：
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作者：
Broll, Marian Sebastian;Geissler, Ute;Lang, Klaus Dieter
采用电子背散射衍射（EBSD）和纳米压痕技术研究了高纯粗铝丝在超声键合工艺和功率循环（APC）后的显微组织梯度，特别是晶体织构梯度的演变。研究结果提高了对引线键合后和APC过程中微观结构变化和排列的认识。超声变形后的引线键合，一个明显的旋转立方体（RC）纹理区域内的楔形的演变被证明是由EBSD分析。讨论了RC织构是剪切变形和晶粒定向生长的结果。RC纹理区域内的硬度降低为引线键合期间的局部软化效应提供了证据。在APC过程中，除了裂纹扩展，晶粒粗化以及局部小角度边界迁移发生，楔形织构的变化，以一个整体的随机取向。讨论了微结构对裂纹扩展行为的影响，并提出了提高引线键合可靠性的建议。(C)2015爱思唯尔有限公司版权所有。
The evolution of microstructural gradients, especially crystallographic texture gradients, after ultrasonic wire bonding process and after active power cycling (APC) of high purity, heavy aluminum (Al) wires is studied by electron backscatter diffraction (EBSD) and nanoindentation. The results improve the knowledge about microstructural changes and arrangements after wire bonding and during APC. After ultrasonic deformation by wire bonding, the evolution of a distinct rotated cube (RC) textured area within the wedge was proved by EBSD analysis. The RC texture is discussed as a result of shear deformation and oriented grain growth. Decreased hardness within the RC textured area provides evidence for local softening effects during wire bonding. During APC, besides crack propagation, grain coarsening as well as local low angle boundary migration occurs and the wedge texture changes to an overall random orientation. Effects of microstructure on the crack growth behavior were discussed and suggestions for the improvement of wire bond reliability were derived. (C) 2015 Elsevier Ltd. All rights reserved.