Abstract In electronic assemblies, quad flat package (QFP) is a widely used packaging method and its interconnection structure degradation is an important field in electronic reliability research. Although degradation processes and failure modes of QFP are various, presently, there are few researching articles on the degradation regularity and mechanism under the same failure mode. In this paper, QFP degradation experiment has been carried out. Three typical QFP degradation processes and failure modes are obtained by experiment data and crack microscopic analysis. Degradation features and curves are extracted through the health index from fusion of dynamic principal component and Mahalanobis distance(PCMD). The regularity shows that there is a similar inflection point in degradation rate curves, and degradation rates are significantly different after this point. Then, according to Darveaux failure physical model, the strain energy distribution of the crack initiation and propagation area is obtained by finite element simulation. Results show that average strain energy density in crack initiation area is similar but in crack propagation area is not, resulting in crack initiation at similar time but the crack propagation rate is different.

中文翻译：

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基于PCMD健康指数和Darveaux模型的QFP互连结构退化研究

摘要 在电子组件中，四方扁平封装(quad flat package，QFP)是一种广泛使用的封装方法，其互连结构退化是电子可靠性研究的一个重要领域。虽然QFP的退化过程和失效模式多种多样，但目前关于同一失效模式下退化规律和机理的研究文章很少。本文进行了QFP降解实验。通过实验数据和裂纹显微分析得到三种典型的QFP退化过程和失效模式。通过动态主成分与马氏距离(PCMD)融合的健康指数提取退化特征和曲线。规律性表明降解率曲线存在相似的拐点，在此之后，降解率明显不同。然后，根据Darveaux破坏物理模型，通过有限元模拟得到裂纹萌生和扩展区域的应变能分布。结果表明，裂纹萌生区的平均应变能密度相似而裂纹扩展区的平均应变能密度不同，导致裂纹萌生时间相近，但裂纹扩展速率不同。