Creep, stress relaxation, and plastic deformation in Sn-Ag and Sn-Zn eutectic solders
Creep, stress relaxation, and plastic deformation in Sn-Ag and Sn-Zn eutectic solders
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锡 - 银和锡 - 锌共晶焊料中的蠕变、应力松弛与塑性变形
DOI：
10.1007/s11664-997-0252-z
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发表时间：
1997-07
影响因子：
2.1
通讯作者：
H. Mavoori;J. Chin;S. Vaynman;B. Moran;L. Keer;M. Fine
中科院分区：
文献类型：
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作者：
H. Mavoori;J. Chin;S. Vaynman;B. Moran;L. Keer;M. Fine
由于电子器件中使用的焊料的高同源操作温度，依赖于时间和温度的松弛和蠕变过程影响其机械行为。本文研究了两种共晶无铅钎料（96.5Sn-3.5Ag和91 Sn-9 Zn）的蠕变和应力松弛行为。蠕变试验在25和80°C两个温度下在10-22 MPa范围内的初始应力下进行。应力松弛测试在恒定应变条件下进行，应变范围为0.3-2.4%，温度为25和80°C。由于蠕变/松弛过程即使在环境温度下的单调拉伸试验期间也是活跃的，因此不同温度和应变速率下的应力-应变曲线提供了对这些过程的深入了解。从单调拉伸，应力松弛，蠕变试验获得的激活能进行了比较和讨论的光的管理机制。这些数据沿着蠕变指数，应变率敏感性和损伤机制是有用的，以帮助建模的焊料互连的可靠性和寿命预测。采用基于蠕变塑性统一理论的本构模型对高温合金的蠕变和应力松弛行为进行了建模，并取得了满意的结果。
Because of the high homologous operation temperature of solders used in electronic devices, time and temperature dependent relaxation and creep processes affect their mechanical behavior. In this paper, two eutectic lead-free solders (96.5Sn-3.5Ag and 91Sn-9Zn) are investigated for their creep and stress relaxation behavior. The creep tests were done in load-control with initial stresses in the range of 10-22 MPa at two temperatures, 25 and 80°C. The stress relaxation tests were performed under constant-strain conditions with strains in the range of 0.3-2.4% and at 25 and 80°C. Since creep/relaxation processes are active even during monotonie tensile tests at ambient temperatures, stress-strain curves at different temperatures and strain rates provide insight into these processes. Activation energies obtained from the monotonic tensile, stress relaxation, and creep tests are compared and discussed in light of the governing mechanisms. These data along with creep exponents, strain rate sensitivities and damage mechanisms are useful for aiding the modeling of solder interconnects for reliability and lifetime prediction. Constitutive modeling for creep and stress relaxation behavior was done using a formulation based on unified creep plasticity theory which has been previously employed in the modeling of high temperature superalloys with satisfactory results.