疊合封裝(Package on Package, PoP)可高度整合邏輯元件與記憶體，並達到微型化，滿足電子產品之小尺寸、低成本、高性能表現與多功能性等發展需求，乃是目前應用最廣泛的3D堆疊封裝技術之一。
本文使用ANSYS12.0進行分析，根據JEDEC規範施予PoP疊合封裝體-40℃~125℃的溫度循環負載，然後使用收斂分析搭配全域/局部法提升模擬分析效率。除錫球考慮為黏塑性材料，其餘皆視為彈性，並以錫球累積應變能密度平均值作為評估整體可靠度之指標，藉由Darveaux提出之理論來預測封裝體之疲勞壽命。其次，利用部分因子分析法篩選出對封裝體壽命影響較大之因子，再導入反應曲面建立正規化迴歸模型。
最後，將所建立之正規化迴歸模型引用基因遺傳演算法求得最佳設計參數組合及最佳化反應值，封裝體疲勞壽命由原始設計2157次循環提升49%至3212次循環；並透過區間式基因遺傳演算法，設定合理目標誤差，搜尋各參數之區間範圍，以了解各參數對可靠度指標之敏感度。

To meet the demands for miniaturization, lightening, high performance, low cost and multi-functions in electronics industries, the Package-on-package (PoP) stacking approach is recognized as an economical solution for integrating the logic and memory devices together and hence achieves size reduction. Therefore, PoP is one of the 3D vertical packaging techniques broadly applied in the manufacture process of electronic products nowadays.
This paper adopts ANSYS 12.0 software for analysis. Based on the JEDEC code, the PoP is subjected by a thermal cycle of -40℃~125℃. The solder ball is assumed to be viscoplastic, and the others are assumed to be elastic. The finite-regional convergence method and the Global/Local method are jointly adopted to promote the efficiency of simulation. The average strain energy density accumulated in the solder ball is treated as the index for evaluating the reliability of the package, and the Darveaux theory is applied to predict the fatigue life of the PoP package.
Secondly, the factors with more significant effect on reliability are chosen as the design parameters by the fractional factorial design method and the regression model of the response surface is developed.
Finally, the genetic algorithm is introduced to the regression model to obtain the optical combination of parameters and response. As a result, it shows that the fatigue life of the package has 49% increases from 2157 to 3212 circles. Moreover, the allowable error range is set up properly and then the range of each design parameter is determined by interval genetic algorithm (IGA) to understand the sensibility of each design parameter related to the reliability.

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