本文提出解決方案來預測於IC封裝充填製程所發生的金線偏移與托盤偏移現象。於模流分析過程中，網格數量通常可高達50萬至100萬，對於如此大量的網格數目，為了要縮短分析時間與增進準度，使用高品質的網格是必須的。本文介紹一種非常適用於IC封裝分析的網格產生方法 - 使用堆疊的概念並結合模型建構與網格產生。在金線偏移分析中，本文介紹一種較直接且方便的方法來考慮金線密度 - 將金線建立於模流分析的網格中，實驗證實此法可以較精準地預測金線偏移量，並且有考慮金線密度的準確度會比沒有考慮金線密度要來的好。

　　托盤偏移泛指導線架與晶片的變形偏移，過大的偏移可能會降低對於內部元件的保護效果，還會影響到金線的偏移量。本文介紹一種分析方法來預測托盤偏移的量，經由計算在充填過程中導線架與晶片所受到來自塑料的壓力，並且將此壓力轉換到結構變形分析中以作為受力來源。

　　另外，本文亦討論不同網格元素在整體托盤偏移分析中的表現優劣，結果顯示六面體網格或三角柱網格是遠比四面體網格適合於IC封裝分析。

　This thesis presents solutions to predict the wire sweep and paddle shift phenomenons occurring during the molding process.

　In the presented solution, the element number of mesh model is often between 500,000 ~ 1,000,000. For such large mesh model, the use of high quality mesh is important to decrease the computation time and increase the accuracy. Therefore, a suitable pre-processing solution, which combines the layer-based solid modeling and element extrusion method, is presented.

　This thesis presents a more direct and convenient approach to consider the wire density effect on the predicted amount of wire sweep by including wires in the mesh model for 3-D mold filling analysis. By comparison with experimental results, it is shown that this approach can more accurately describe the wire density effect.

　A methodology for computational modeling and prediction of paddle shift is presented. The methodology is based on modeling the flow of the polymer melt around the leadframe and paddle during the filling process, and extracting the pressure loading induced by the flow on the paddle. The pressure loading at different times during the filling process is then supplied to a three-dimensional, static, structural analysis module to determine the corresponding paddle deflections at those times. Meanwhile, the effect on the overall model performance of different element types for the mold filling analysis and the structural analysis is also investigated and discussed. In order to obtain more accurate results and a shorter computational time, it is found that higher-order elements, such as hexahedrons or prisms are more suitable than tetrahedrons.

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