隨著科技的日新月異，對於電子產品的功能以及攜帶性要求越來越嚴苛。為了因應上述兩種要求，除了在IC 設計技術上投入巨大的研發成本以及人力之外，電子封裝技術也從傳統的DIP (Dual In-line Package)發展出具有高密度I/O (Input and Output) 以及較小覆蓋區 (Footprint)的覆晶 (Flip Chip)封裝、晶片級封裝(Chip Scale Package, CSP)、晶圓級封裝 (Wafer Level Package, WLP)以及扇出型(Fan-out)封裝。另外也更進一步發展3D 封裝技術來維持摩爾定律(Moore's Law)的發展並提出More than Moore象徵此技術將使半導體工業的發展將超越摩爾定律。
熱循環負載測試(Thermal Cycling Test, TCT)為其中一項取得電子元件可靠度的實驗方法，然而因為進行實驗需要花費相當龐大的成本。因此近年業界採用有限元素分析來減少實驗次數，同時減少產品開發成本以及時程，然而採用有限元素分析依然需要耗費相當多時間，當研發人員未受過充足訓練時則會導致不同的研發人員所獲得的計算結果不一致。現今隨著電腦硬體設施的效能不斷進步，機器學習方法的應用蓬勃發展，因此本研究目地為探討是否能利用支援向量回歸(Support Vector Regression ,SVR)方法預測晶圓級封裝之可靠度，其中包含單核心支援向量迴歸 (Single Kernel SVR)、多核心支援向量迴歸 (Multiple Kernel SVR) 以及新型支援向量迴歸 (ν-SVR)，並設法透過不同的訓練資料量、不同的測試資料集詳細探討前述支援向量迴歸模型之預測效能及其穩定性，最後希望能提供一個快速且有效的預測模型給前端設計研發人員檢視設計參數的可行性。
本研究將依照下列步驟執行，首先利用實驗驗證本研究所使用的有限元素分析方法以及Coffin-Manson 壽命預估公式所得到的結果；接著在固定材料和負載的情況下，給定不同的幾何結構參數值，建立WLCSP之錫球可靠度數據庫；再來透過支援向量迴歸方法預測WLCSP之錫球可靠度，並評估此預測模型之預測效能及其穩定性；最終除了探討是否能利用增加訓練資料樣本數或是不同的支援向量迴歸方法來增進預測效能之外，也探討對於特定測試資料預測效能不足之問題，是否能透過增加與該測試資料相似的訓練樣本來獲得改善。本研究顯示支援向量迴歸模型預測效能十分穩定，增加訓練樣本數與採用不同支援向量回歸方法設定皆能增進預測效能，對於特定測試資料預測效能不足之問題也能透過增加與該測試資料相似的訓練樣本來得到改善。

With the rapid development of technologies, the electronic devices are asked to be thinner, smaller, and more powerful to meet the market demands. The electronic packaging technology evolves from a conventional package structure such as Dual In-line Package (DIP) to the structure with a smaller footprint and higher I/Os (Input and Output), such as Flip Chip (FC), Chip-Scale Package (CSP), Wafer Level Package (WLP) and Fan-out (FO) Packages. Moreover, 3D packaging technologies are developed to break the limitation of the existing Moore’s Law, the term “More than Moore” is proposed to represent that these developing technologies will help the development of the semiconductor industry to go beyond the limitation of Moore’s Law.
Thermal cycling test (TCT) is one of the important experimental approaches to obtain the reliability of the electronic packages. However, the experimental approach will take great amounts of time and cost to obtain the result of reliability. Therefore, finite element analysis (FEA) is introduced to reduce the number of experiments. While implementing finite element analysis still needs to take a lot of time and effort to apply appropriate simulation techniques to construct the model and simulates the process of TCT. Furthermore, different results will be obtained by the different researchers if the researchers are lacking proper training. Thus, the purpose of this research is applying the machine learning techniques, which benefit from the improvement of computer infrastructures that provides high-speed computation and the huge amount of storage, to predict the reliability of wafer level chip scale package (WLCSP), to provide an efficient and a reliable predictive model for front-end designers to check the feasibility of their design. This research adopts the algorithm of support vector regression (SVR), which is one of the machine learning techniques, including the single kernel, multiple kernel, and nu-SVR (ν-SVR) techniques. The evaluation for predictive performance and the stability of the predictive performance of the predictive model obtained by using this approach are discussed in this research. As for discussion of the approaches to improve the predictive performance are also included in this research, such as the implementation of the different training dataset, increasing the number of similar training sample for the specific test sample that cannot be predicted well by the predictive model, and application of multiple kernel SVR and ν-SVR.
In order to accomplish the research goal, this study will be carried out accordance to the following steps: first, verifying the result obtained by finite element analysis method used in this study and Coffin-Manson model by reference experimental data; second, constructing the reliability database for WLCSP by the validated finite element analysis approach with fixed material properties and thermal cycling loading but different geometry design parameters; third, obtain the predictive reliability of WLCSP through the predictive model obtained by using single kernel SVR, multiple kernel SVR, and ν-SVR, evaluating the prediction accuracy and stability of the predictive performance of predictive model; fourth, discuss the effect of adopting following approaches to improve the performance of the predictive model such as increasing the number of training sample, increasing the number of similar training sample for the specific test sample that cannot be predicted well by the predictive model, and implementing the multiple kernel SVR and ν-SVR. The results of this study indicate that the predictive performance of the predictive model obtained by using SVR is stable. Moreover, it can be improved by adopting approaches such as increasing the number of training samples, increasing the number of similar training sample for the specific testing sample that cannot be predicted well by the predictive model. Considering the predictive performance and training time, the ν-SVR technique is more suitable with small amount of training samples in this research, while the single kernel SVR technique is suitable with larger amount of training samples in this study.

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