晶圓重組 (reconstitution) 必須經歷一系列壓模、後熟化、卸除載盤等製程，其中壓模速度、壓力、溫度以及時間等參數設定，對製程良率維持而言是極為關鍵的因素。若未能妥善地設定這些參數，將可能造成重組後晶圓在外觀上明顯可見的缺陷，如晶圓翹曲 (wafer warpage) 以及晶粒偏移 (die shift) 等直接降低製程良率的現象。
所謂晶粒偏移是由製程中的模流因素負載和各材料間熱膨脹係數 (coefficient of thermal expansion；CTE) 差異所致之熱應力，與封膠固化收縮時所產生之殘留應力，以及長時間處於高溫時封膠所產生之黏彈效應等固力因素交互作用所致，而本論文主要評估這些模流因素與固力因素對製程所造成的缺陷。論文中我們利用簡化之流體力學與固體力學有限元素模型，同時透過實驗來量測底膠黏著力與封裝材料機械性質(包括楊氏模數及黏彈性行為參數等)，做為分析模型中的材料參數，來計算並探討造成晶粒偏移原因及數量級評估。計算結果中所顯示可能產生之晶粒偏移趨勢大致與製程現場之觀察一致，在經過對晶圓重組製程進行有系統的參數研究與實驗驗證分析後，我們也試著提出對於晶粒偏移之改善方案，以期降低前述各項缺陷在產線上實際發生之機率，進而達成改善製程良率之重要終極目的。

In advanced packaging technologies, there are many important parameters in the wafer reconstitution process, such as molding velocity, pressure, temperature and duration of each process. Without proper tuning of these parameters, some serious defects typically appear after wafer reconstitution, such as die shift and wafer warpage. These defects clearly may decrease the yield. In this thesis, we utilize simplified fluid dynamics model and FEM analysis to determine the main cause of die shift. And it turns out that die shift is mainly caused by the interaction of fluid force loading, material thermal expansion, shrinkage of molding compound and viscoelastic effect. In the meantime, we also set up experiments to measure material properties, such as the elastic moduli of the compound and the tape, under different temperatures, tape adhesive strength, viscoelastic effect parameters, etc. After we finish these measurements, we then input these material parameters into the FEM software ABAQUS to simulate the real process conditions, and carry out a full analysis of wafer reconstitution process. Finally, the simulation results of ABAQUS show that the tendency and magnitude of die shift and warpage are similar to the results observed in real process. With this successful simulation, we can then analyze the effectiveness of some alleviation strategies for reducing the occurrence of defects after the wafer reconstitution process.

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