Experimental Damage Mechanics of Microelectronics Solder Joints under Concurrent Vibration and Thermal Loading
Experimental Damage Mechanics of Microelectronics Solder Joints under Concurrent Vibration and Thermal Loading
复制标题
振动和热载荷同时作用下微电子焊点的实验损伤机制
DOI：
10.1106/hlb3-mjc8-jvyl-9a9p
复制
发表时间：
2001
影响因子：
4.2
通讯作者：
Ying Zhao
中科院分区：
文献类型：
--
作者：
C. Basaran;A. Cartwright;Ying Zhao
在电子封装的使用寿命中，例如汽车、飞机、军事和移动电子设备，通常会遇到同时发生的振动和热负载。焊点可靠性一直是微电子器件整体设计的关键问题。然而，振动对焊点热疲劳寿命的影响却很少被研究。目前，振动被视为仅引起弹性材料响应的载荷工况。关于微米级结构的振动塑性和振动引起的疲劳的文献很少。行业内的标准做法是使用Miner法则来计算组合环境疲劳寿命。这项研究表明，对于微米级焊点，使用 Miner 法则计算组合载荷下的疲劳寿命是不准确的。有许多本构模型可以模拟焊点的热机械行为，但其中很少有模型（如果有的话）通过从实际微电子焊点获得的测试数据进行验证。作者认为需要进行此类测试，以便更好地了解热和振动载荷下微米级焊点的材料行为，并为更准确的材料建模和疲劳寿命预测提供坚实的基础。本文报告了对实际球栅阵列 (BGA) 封装的 63Sn/37Pb 焊点进行的一系列并发热循环和振动测试的观察结果。莫尔干涉仪（MI）用于以亚微米分辨率测量焊点的非弹性变形场。大容量Super AGREE热室和高加速度电动振动台组装在一起以执行并发循环。讨论了焊点的循环塑性和微观结构演变，并将其与疲劳寿命预测联系起来。这项研究获得的结果与微米级材料测试文献中报道的结果一致，其中表明“越小越好”。
Concurrent vibration and thermal loading is commonly encountered in the service life of electronic packaging, such as in automotive, airplane, military and mobile electronic devices. Solder joint reliability has been a critical issue of the overall design of microelectronic devices. However, the contribution of vibration to thermal fatigue life of solder joints has rarely been investigated. Presently, vibration is taken as a loading case that only causes elastic material response. Literature is scarce on vibration plasticity and vibration caused fatigue for micron scale structures. The standard practice in the industry is to use Miner’s rule to calculate combined environment fatigue life. This study shows that using Miner’s rule for fatigue life under combined loading is inaccurate for micron scale solder joints. There are a number of constitutive models to simulate thermomechanical behavior of solder joints, yet few of these, if any, models are verified by test data obtained from actual microelectronics solder joints. The authors see the need of such tests for the purpose of better understanding of material behavior of micron scale solder joints under thermal and vibration loading and providing a solid basis for more accurate material modeling and fatigue life prediction. This paper reports observations from a series of concurrent thermal cycling and vibration tests on 63Sn/37Pb solder joints of an actual ball grid array (BGA) package. Moiré interferometry (MI) is used to measure the inelastic deformation field of solder joints with submicron resolution. A large capacity Super AGREE thermal chamber and a high acceleration electrodynamic shaker are assembled together to perform the concurrent cycling. The cyclic plasticity of solder joints and microstructure evolution are discussed and related to fatigue life prediction. The results obtained in this study agree with findings reported in the literature from micron scale material testing where it has been shown that “smaller is stronger.”