電子產品發展，趨向「輕薄、多功能、高元件密度、耐久性」等要求演進。當微電子晶片功能傾向高功率、高密度與高速度時，其單位面積發熱量急速增加，而封裝體的體積逐漸縮小，其散熱不良是產品產生失效的原因。本文之研究在於針對四方形扁平無引腳封裝(QFN)及球柵陣列封裝(BGA)，改變其封裝體的幾何結構尺寸與材料之參數，以達到最佳的散熱性能，使封裝體因散熱不良所導致失效的機率大為降低。
在業界上，不管改變何種尺寸或是材料來進行實驗都是需要相當大的風險與成本。所以本文針對四方形扁平無引腳封裝(QFN)及球柵陣列封裝(BGA)封裝體進行數值解析，利用分析軟體ANSYS之ICEPAK來建立模型，進而模擬在自然對流條件下的散熱性能，配合統計實驗設計田口法L18 (21×37)直交表設定參數之組合，求得各個控制因子的影響效果程度，接著利用ANOVA(ANalysis Of VAriance)變異數分析來獲得各個控制因子的貢獻度，最終進行變異數誤差統合，俾便找出各個參數的顯著程度。
結果顯示，QFN封裝體的黏著劑(Die attach)熱傳導係數影響其散熱性能高達81.46%，且相較於其它控制因子而言，具有高顯著性與高影響效果，而Die attach熱傳導係數在0.5 W/m•k至1.5 W/m•k之間的晶片表面溫度(Tj)下降幅度遠大於1.5 W/m•k至8 W/m•k之間。而BGA封裝體的晶片/封裝體(Die/PKG)面積比影響其散熱性能則為64.24%，其顯著性與影響效果同樣大於其它控制因子，而增大Die/PKG SIZE可大幅降低晶片表面溫度(Tj)；至於基材( Substrate)層數的貢獻度為18.83%，在99%的信心水準下也擁有較高顯著性。

Currently the trend of electronic product development is to ward “light and thin, multi-functional, high density and durability”. When the microelectronic chips tend to be high power, high density and high speed, the rapid increase of heat in a reduced unit area of package size, will lead to failure of electronic products. The contents of thesis is to find out the dominant factors in heat transfer by changing the geometries and material properties of QFN and BGA packages. It also aims to achieve the beat the thermal performance by reducing the probability of failure.
In industries it needs a lot of cost and time in experiment work due to the changes of size and materials. Herein, the softwares of ANSYS and ICEPAK are adopted to model the QFN and BGA packages with the statistical experimental design of Taguchi method L18 (21×37) orthogonal array setting parameters and obtain the degree of effect for each factor. Eventually, we use the analysis of variance ANOVA to obtain the contribution of each factor and to identify the significant degree for various parameters by variance error integration.
From the results the die attach thermal conductivity affects the contribution of thermal performance up to 81.46% for QFN package in comparison with other controlling factors of high significance and high impact effects. Die attach thermal conductivity between 0.5 W/m•k and 1.5 W/m•k the Tj declines much larger than that between 1.5 W/m•k and 8 W/m•k. Die /PKG area ratio affects the contribution of the thermal performance to 64.24% and increasing Die /PKG area ratio can reduce the Tj for BGA package. The significant effect is also higher than other factors. However, the contribution of substrate layers is 18.83% at 99% confidence level.

目 錄
摘 要 i
ABSTRACT ii
目 錄 iii
圖 次 v
表 次 viii
第一章 緒論 1
1.1 前言 1
1.2 熱傳簡介 2
1.3 研究目的與動機 6
1.4 文獻回顧 7
1.5 組織與章節 8
第二章 理論基礎 13
2.1 熱阻基本定義 13
2.1.1熱阻θJA 13
2.1.2熱阻θJB 14
2.1.2熱阻θJC 14
2.2田口實驗設計方法 15
2.2.1田口方法介紹 15
2.2.2變異數分析 17
第三章 數值模擬與分析流程 24
3.1 Fluent Icepak簡介 25
3.2 統御方程式 25
3.3 數值模型之建立 26
3.3.1 QFN 26
3.3.2 BGA 27
3.4 分析流程與參數規劃 27
3.4.1 目標函數選定 27
3.4.2 控制因子與水準數 28
3.4.3 訂定田口直交表 30
3.5 實驗熱阻量測 30
3.5.1 測試晶片 30
3.5.2 測試環境 31
3.6 模擬分析 31
3.6.1 網格建立 32
3.7 模擬驗證 32
第四章 模擬結果 47
4.1 QFN之田口分析最佳參數組合 47
4.2 BGA之田口分析最佳參數組合 49
第五章 分析討論 54
5.1 QFN之變異數分析統合 54
5.2 BGA之變異數分析統合 55
5.3 最佳控制因子對散熱之影響 57
5.3.1 不同的Die attach熱傳導係數對QFN之影響 57
5.3.2 不同的Die尺寸對BGA之影響 58
第六章 結論 77
參 考 文 獻 79

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