在許多工程問題上常使用傳統正算方法來求解其物理量，亦就是探討將已知條件輸入系統模式來分析其輸出為何，這就是正算問題(Direct Problem)。然而在許多實際工程問題中，存在著很多物理量因為客觀條件限制或量測技術不足而無法直接計算或量測其值。因此，為了取得所需之物理量，必須利用反算法藉由其它已知的參數或物理量反求之，這就是逆向或反算問題(Inverse Problem)。由於電子元件的熱傳問題在現今科技產業中，其所佔的重要性與日遽增，再加上目前的趨勢走向高科技、微電子產業，是故在晶片的發熱量增加且體積縮小的情形下，元件的壽命與其溫度分佈情形有極大之關連。對於電子產品而言，過高的溫度會損害到晶片的壽命，甚至造成整個系統的不穩定。
　　有鑑於此，本論文分為兩章節，所使用反算法和最佳化方分別為共軛梯度法和拉凡格式法，在第二章將反算法之共軛梯度法運用在預測晶片內部之熱傳問題上，使用商業軟體CFD-ACE+來建立複雜物理模型的幾何形狀與網格，期望能以數值分析的方式利用CFD-ACE+所解得上表面溫度分佈情形作為反算的依據，即可預測出內部未知熱源強度之預測出內部熱源強度。在第三章中，利用第二章之晶片上方加入散熱模組使其幫助散熱，同樣利用軟體建立幾何模型並結合最佳化方法-拉凡格式法，針對散熱模組之設計參數進行最佳化預測；本章節散熱模組散熱方式是由氣體冷卻下吹式冷卻配置的條件下，來對於尺寸參數組合進行最佳化研究。

　In many practical engineering applications the direct problem is utilized to solve for its physical quantity by substituting the known parameters to the system. However in many actual problems, many physical quantities are impossible to calculate or to measure directly and the techniques for inverse problems are needed to obtain these values. Nowadays, the trend in microelectronics is toward increasing higher input/output, higher component density and higher electrical performance, which makes thermal enhancement to package performance an increasingly important issue.
　The present thesis divides into two chapters; the techniques of the Conjugate Gradient Method (CGM) and Levenberg-Marquardt Method are applied, respectively. In chapter two, a three-dimensional inverse heat conduction problem is solved by using the Conjugate Gradient Method (CGM) and the general purpose commercial code CFD-ACE+ is examined to estimate the strength of the unknown heat generation for an encapsulated chip in a three-dimensional irregular domain based on the simulated measured temperature distributions on surface by the simulated infrared thermography.
　In chapter three, a three-dimensional inverse design problem in estimating the design variables for heat sink modules with an encapsulated chip is solved by using the Levenberg-Marquardt Method (LMM) and the general purpose commercial code CFD-ACE+ in an irregular domain. Three different types of heat sinks are examined at a fixed fin array volume to determine the most efficient type of heat sink. Moreover, Alumina and Copper heat sinks are compared to find the optimum design of the module.

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