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1.
Fatigue damage behavior of a surface-mount electronic package under different cyclic applied loads 下载免费PDF全文
This paper studies and compares the effects of pull-pull and 3-point bending cyclic loadings on the mechanical fa- tigue damage behaviors of a solder joint in a surface-mount electronic package. The comparisons are based on experimental investigations using scanning electron microscopy (SEM) in-situ technology and nonlinear finite element modeling, respec- tively. The compared results indicate that there are different threshold levels of plastic strain for the initial damage of solder joints under two cyclic applied loads; meanwhile, fatigue crack initiation occurs at different locations, and the accumulation of equivalent plastic strain determines the trend and direction of fatigue crack propagation. In addition, simulation results of the fatigue damage process of solder joints considering a constitutive model of damage initiation criteria for ductile materials and damage evolution based on accumulating inelastic hysteresis energy are identical to the experimental results. The actual fatigue life of the solder joint is almost the same and demonstrates that the FE modeling used in this study can provide an accurate prediction of solder joint fatigue failure. 相似文献
2.
C. -H. Chien Y. -C. Chen C. -C. Hsieh Y. -T. Chiou Y. -D. Wu T. -P. Chen 《Experimental Mechanics》2004,44(2):214-220
With the increasing application of flip-chip technology in the microelectronics industry, the adhesion strength of interfaces
in flip-chip microelectronic structures has become an important issue for manufacturing and operation. In this paper we present
an experimental investigation of the adhesive strength of underfill material to solder mask coated FR-4 substrate under thermal
cycling. The effects of the number of thermal cycles on interfacial strength were investigated by using the button shear test.
The relationship between interfacial strength and the thickness of solder mask was also examined. Furthermore, the morphologies
of fracture surfaces of the test specimens were analyzed by scanning electron microscopy. The results of this study show that
the interfacial strength of the underfill/solder mask/substrate joint was significantly reduced by thermal fatigue. Finally,
the degradation behavior and possible mechanisms were then determined on the basis of these observations. 相似文献
3.
Shi Xunqing Wang Zhiping John HL Pang Zhang Xueren Nie Jingxu 《Acta Mechanica Sinica》2002,18(3):274-287
In this study, a new unified creep constitutive relation and a modified energy-based fatigue model have been established respectively
to describe the creep flow and predict the fatigue life of Sn−Pb solders. It is found that the relation successfully elucidates
the creep mechanism related to current constitutive relations. The model can be used to describe the temperature and frequency
dependent low cycle fatigue behavior of the solder. The relation and the model are further employed in part II to develop
the numerical simulation approach for the long-term reliability assessment of the plastic ball grid array (BGA) assembly.
The project supported by the National Natural Science Foundation of China (59705008) 相似文献
4.
Because of the increasing complexity and cost of experiments carried out, the data for the multi-component alloy systems have frequently been obtained by numerical modelling. It is clear that the related calculations require reliable data dealing with the pure components and binary alloy systems. Selecting the reliable data concerning the pure components from the literature, the viscosities for the SAC and (SAC)1?x Cox solder alloys have been calculated using different viscosity models (geometric and physical). The viscosity decreases as the amount of tin content increases in the SAC387 alloy while the addition of the cobalt to SAC387 solder results in the increasing of the viscosity. Moreover, by computing the root mean square values between theoretical and experimental viscosities, it can be concluded that the lowest value among all models is that of obtained by Kaptay equation. 相似文献
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电子封装技术中, 微互连焊点在一定温度梯度下将发生金属原子的热迁移现象, 显著影响界面金属间化合物的生长和基体金属的溶解行为. 采用Cu/Sn/Cu焊点在250℃和280℃下进行等温时效和热台回流, 对比研究了热迁移对液-固界面Cu6Sn5生长动力学的影响. 等温时效条件下, 界面Cu6Sn5生长服从抛物线规律, 由体扩散控制. 温度梯度作用下, 焊点冷、热端界面Cu6Sn5表现出非对称性生长, 冷端界面Cu6Sn5生长受到促进并服从直线规律, 由反应控制, 而热端界面Cu6Sn5生长受到抑制并服从抛物线规律, 由晶界扩散控制. 热端Cu 基体溶解到液态Sn中的Cu原子在温度梯度作用下不断向冷端热迁移, 为冷端界面Cu6Sn5的快速生长提供Cu 原子通量. 计算获得250℃和280℃下Cu原子在液态Sn中的摩尔传递热Q*分别为14.11和14.44 kJ/mol, 热迁移驱动力FL分别为1.62×10-19和1.70×10-19 N. 相似文献
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The surface tensions of ternary and quaternary systems of Sn-based Pb-free solder alloys have been calculated using geometric models, such as Muggianu, Kohler, Chou’s general solution model (GSM), Toop, Guggenheim, ideal Butler and Butler models. It is observed from the calculation carried out in the present work that Sb and Bi contents decrease the surface tension of the solder alloys Sn-Zn-Sb-Bi. It is inferred from the statistical analysis that the best agreement between the experimental results and the corresponding calculated values of the surface tensions is generally observed in GSM and Muggianu models among the geometric models. Whereas Muggianu model is the most appropriate. Relatively good agreements have been observed between models considered in this study and experimental data. 相似文献
10.
为研究焊锡接点金属间化合物微结构对其微观-宏观力学行为的影响,采用Voronoi图算法构造了金属间化合物的晶粒尺度几何模型,通过在晶粒界面配置内聚力界面单元,提出了模拟金属间化合物晶粒界面裂纹起裂、扩展与连通的有限元数值模拟方法。基于该方法,研究了晶粒形状和晶粒界面缺陷对晶界微开裂模式和整体响应的影响,研究了金属间化合物微结构对焊锡接点强度和破坏模式的影响。结果表明,晶粒形状对整体强度影响不大,但对微裂纹开裂模式有影响。当考虑晶界随机缺陷时,强度较低的晶粒界面对整体强度影响较大。金属间化合物层的厚度对焊锡接点强度和破坏模式均有影响,而金属间化合物与焊料界面的粗糙度主要影响焊锡接点的破坏模式。 相似文献