Purpose

This study aims to investigate the effect of ultrasound on interfacial microstructures and growth kinetics of intermetallic compounds (IMCs) at different temperatures.

Design/methodology/approach

To investigate the effect of ultrasound on IMCs growth quantitatively, the cross-sectional area of IMCs layers over a confirmed length was obtained for calculating the thickness of the IMCs layer.

Findings

The generation of dimensional difference in normal direction between Cu₆Sn₅ and its adjacent Cu₆Sn₅, formation of bossed Cu₆Sn₅ and non-interfacial Cu₆Sn₅ in ultrasonic solder joints made the interfacial Cu₆Sn₅ layer present a non-scallop-like morphology different from that of traditional solder joints. At 260°C and 290°C, the Cu₃Sn layer presented a wave-like shape. In contrast, at 320°C, the Cu₃Sn in ultrasonic solder joints consisted of non-interfacial Cu₃Sn and interfacial Cu₃Sn with a branch-like shape. The Cu₆Sn₅/Cu₃Sn boundary and Cu₃Sn/Cu interface presented a sawtooth-like shape under the effect of ultrasound. The predominant mechanism of ultrasonic-assisted growth of Cu₆Sn₅ growth at 260°C, 290°C and 320°C involved the grain boundary diffusion accompanied by grain coarsening. The Cu₃Sn growth was controlled by volume diffusion during the ultrasonic soldering process at 260°C and 290°C. The diffusion mechanism of Cu₃Sn growth transformed to grain boundary diffusion accompanied by grain coarsening when the ultrasonic soldering temperature was increased to 320°C.

Originality/value

The microstructural evolution and growth kinetics of IMCs in ultrasonically prepared ultrasonic solder joints at different temperatures have rarely been reported in previous studies. In this study, the effect of ultrasound on microstructural evolution and growth kinetics of IMCs was systematically investigated.

中文翻译：

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超声波焊接过程中Cu/Sn/Cu体系中金属间化合物的微观结构演变和生长动力学

目的

本研究旨在研究超声对不同温度下金属间化合物 (IMC) 的界面微观结构和生长动力学的影响。

设计/方法/方法

为了定量研究超声对 IMCs 生长的影响，获得了 IMCs 层在确定长度上的横截面积，用于计算 IMCs 层的厚度。

发现

_{Cu 6} Sn ₅与其相邻的Cu ₆ Sn ₅法线方向尺寸差的产生、超声波焊点中凸台Cu ₆ Sn ₅和非界面Cu ₆ Sn _{5的形成使得界面Cu 6} Sn ₅层呈现出不同于传统焊点的非扇贝状形态。在 260°C 和 290°C 时，Cu ₃ Sn 层呈波浪状。相比之下，在 320°C 时，超声波焊点中的 Cu _{3 Sn 由非界面 Cu 3} Sn 和界面 Cu _3组成。Sn 呈树枝状。Cu ₆ Sn ₅ /Cu ₃ Sn界面和Cu ₃ Sn/Cu界面在超声作用下呈锯齿状。_{Cu 6} Sn ₅在260°C、290°C和320°C下超声辅助生长的主要机制是伴随晶粒粗化的晶界扩散。在 260°C 和 290°C 的超声波焊接过程中， Cu ₃ Sn 的生长受体积扩散控制。当超声焊接温度升高至320℃时，Cu _{3 Sn 生长的扩散机制转变为晶界扩散并伴随晶粒粗化。}

原创性/价值

以往的研究很少报道不同温度下超声制备的超声焊点中 IMCs 的微观结构演变和生长动力学。在这项研究中，系统地研究了超声对 IMCs 微观结构演变和生长动力学的影响。