5-1 結論
本論文是以 IcePak 軟體，利用 CFD 的方式並且有效的運用等效 熱阻及非均勻網格等方法來針對目前 III-V 族高頻通訊積體電路電子 覆晶構裝的熱傳現象來做模擬；包括了傳統的覆晶構裝及新提出的同 軸式覆晶構裝設計；將此二種不同形式封裝於封裝體內與封裝體外設 計多種不同情況來探討其散熱的效益，並且經過系統化的整理達到我 們所欲求得的最佳化散熱封裝形式。
其結果顯示：材料對於封裝體內部的影響最劇，且當線路的厚度 在有限尺寸下將其設為8
µ m
對熱的散逸擁有較好的效果，而散熱通孔 的設計則因為個數上的限制對溫度的影響有限。而在外部設計封裝 上，我們應同時考量成本、製程、噪音及溫度影響等問題加以討論；倘若只考慮欲求得最低之熱阻情況時，我們選擇在金屬蓋上加上一基 底為2500µmx2500µmx1500µm，鳍片高度、厚度及間距分別為500、
100 及166µm的熱沈；並於測試入口處加入一 5 m/s 的強制對流時，
則此時封裝體擁有最佳的散熱效果。
因此，經過本文之探討，除了能讓我們對於高頻通訊電路封裝的 散熱最佳化設計有更深入的了解且對同軸式覆晶構裝有新一層面的 認識；並期望能在高頻通訊電路的研究上能帶給人們更廣的視野及提
供日後研究高頻通訊封裝者有效之參考資料。
5-2 未來展望
正常的封裝測試程序是需要模擬以實驗兩大步驟配合方能達到 最正確之結果；不過由於此封裝實體目前還在試驗階段無法從實驗得 知結果相比對，未來等實體完成時，再去做實驗以量測其 Junction Temperature 及熱阻值，並與我們的模擬數據作比對以期達到更正確 的數值。
在此研究當中，提出了底部填膠會對於熱應力(Thermal Stress)有 一定程度的影響；又在封裝的熱分析中除了散熱設計的考量外，熱應 力的分析也佔很大的一角不能忽略。固未來我們可以運用其他有限元 素軟體，利用我們散熱分析之後計算出來的溫度場分布當作邊界條 件，再運用耦合場分析的方式以求得熱應力的分佈情形。
參考文獻
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[8] S. Mulgaonker, and H. M. Berg, “Thermal Sensitivity Analysis for the 119 PBGA –A Framework for Rapid Prototyping” IEEE Transaction on Components, and Manufacturing Technology-Part A, pp.66-75, 1996.
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[26] ICEPAK 4.1 User Guide 2003.
表 2-1 熱分析參數範圍表
表 4-1 傳統式高頻覆晶封裝內部設計 溫度及熱阻分佈圖表
0.04w simulation
Al2O3-PbSn-2mi(4balls) 67.0973 1002.43 330.807 Al2O3-PbSn-2mi(6balls) 63.9711 924.27 229.54 AlN-Au-2mi(6balls) 58.0677 776.6925 103.4425 AlN-Au-8mi(6balls) 57.3611 759.02 85.29 AlN-Au-8mi-4vias(6balls) 57.34 758.5 83.86
表 4-2 同軸式高頻覆晶封裝內部設計
AlN-PbSn-2mi 62.2554 881.385 187.19
AlN-Au-2mi 59.7806 819.5 125.66
AlN-Au-8mi 58.808 795.2 104.22
AlN-Au-8mi-4Vias 58.792 794.79 103.63
表 4-3 傳統式高頻覆晶外部封裝設計 compound and air
58.175 779.38 104.43
with mold compound
57.372 759.3 84.0625
( )
c表4-4 同軸式 Type.0 No enhancement 溫度及熱阻分佈圖表
103.63 794.79
58.79 No enhancement
0
0..0044ww s
siimmuullaattiioonn
T
mean( ) ° c R
ja( ) ° c w R
jb( ) ° c w
表4-5 同軸式 Type.1 With heat spreader 溫度及熱阻分佈圖表
99.53 781.12
58.25 With Al heat spreader
25micros With Cu heat spreader
50micros
表4-6 同軸式 Type.2 With heat spreader and soft pad 溫度及熱阻分佈圖表
103.63 794.79
58.79 No enhancement
67.0 747.08
56.88 With 50micros Cu heat spreader
and 200 micros soft pad
65.38 745.52
56.82 With 50micros Cu heat spreader
and 300 micros soft pad 0
0..0044ww sisimmuullaattiioonn
( )
cTmean ° Rja
( )
°cw Rjb( )
°cw註:當soft pad 增為 400 mµ 時 ,變化範圍非常之小,為節省空間故選擇 300 mµ 之 pad
表4-7 同軸式 Type.3 With metallic lid 溫度及熱阻分佈圖表
103.63 794.79
58.79 No
enhancemen
59.02 744.15
56.77 With aluminum lid
56.17 741.41
56.66 With copper lid
0
0..0044ww sisimmuullaattiioonn
( )
cTmean ° Rja
( )
°cw Rjb( )
°cw表4-8 同軸式 Type.4 With mold compound (varying percentage of converage,25%)
溫度及熱阻分佈圖表
103.63 794.79
58.79 No enhancement
102.0 791.98
58.64 With mold compound, the gap is
25micros, Mold compound covers 25% of the substrate
0
0..0044ww
ssiimmuullaattiioonn Tmean
( )
°c Rja( )
°cw Rjb( )
°cw表4-9 同軸式 Type.5 With mold compound
With mold compound, the gap is 25 micros, Mold compound covers the entire substrate
99.23 779.95
58.19
With mold compound, the gap is 50 micros, Mold compound covers the entire substrate
0
表4-10 同軸式 Type.6 With mold compound and Cu heat spreader (varying gap between the die and the heat spreader)
溫度及熱阻分佈圖表
With mold compound and 25 micros thick Cu heat spreader, the gap is 50micros, Mold compound
covers the entire substrate
92.24 772.75
57.91
With mold compound and 50 micros thick Cu heat spreader, the gap is 50micros, Mold compound
covers the entiresubstrate
0
表 4-11 熱沈(Heat sink)尺寸設計參數
71 100
500 2500x2500x150
With copper lid and length 2500micros
100 thickness 15 counts aluminum
With copper lid and length 2500micros
100 thickness 10 counts aluminum
With copper lid and length 2500micros
100 thickness 5 counts aluminum
With copper lid and length 1500micros
100 thickness 10 counts aluminum
heat sink
250 100
1500x1500x150 500 With copper lid and
length 1500micros 100 thickness 5 counts aluminum
表4-12 同軸式 Type.7 With metallic and heat sink 溫度及熱阻分佈圖表
53.24 701.57
55.06
With copper lid and length 2500micros 100 thickness 10 counts aluminum heat sink
53.26 684.51
55.04
With copper lid and length 2500micros 100 thickness 15 counts aluminum heat sink
103.63
With copper lid and length 1500micros 100 thickness 5 counts aluminum heat sink
53.48 703.32
55.17
With copper lid and length 2500micros 100 thickness 5 counts aluminum heat sink
0
0..0044ww s
siimmuullaattiioonn
T
mean( ) ° c R
ja( ) ° c w R
jb( ) ° c w
表 4-13 同軸式高頻覆晶封裝外部各設計 之 Rja（Junction-air-resistance）列表 Type
No. Description
Max. Junction-to-air Thermal Resistance
0 No enhancement 794.79
1(a) With Al heat spreader, 25microns 781.12 1(b) With Cu heat spreader, 25microns 780.75 1(c) With Cu heat spreader, 50microns 775.64 2(a) With 50microns Cu heat spreader
and 200 microns soft pad
747.08
2(b) With 50microns Cu heat spreader and 300 microns soft pad
745.52
3(a) With aluminum lid 744.15
3(b) With copper lid 741.41
4 With mold compound, the gap is 25microns, Mold compound covers 25% of the substrate
791.98
5(a) With mold compound, the gap is 25microns, Mold compound covers the entire substrate
785.28
5(b) With mold compound, the gap is 50microns, Mold compound covers the entire substrate
779.95
6(a) With mold compound and 25microns thick Cu heat spreader, the gap is 50microns, Mold compound covers the entire substrate
773.91
6(b) With mold compound and 50microns thick Cu heat spreader, the gap is 50microns, Mold compound covers the entire substrate
772.75
7(a) With copper lid and length 1500microns 100 Thickness 5 counts aluminum heat sink
730.61
7(b) With copper lid and length 2500microns 100 Thickness 5 counts aluminum heat sink
703.32
7(c) With copper lid and length 2500microns 100 Thickness 10 counts aluminum heat sink
701.57
( )
°cw表 4-14 同軸式高頻覆晶封裝
表 4-15 同軸式高頻覆晶封裝
1500-5-Junction-air Resistance
表 4-16 傳統式高頻封裝設計前後
溫度及Rja（Junction-air-resistance）分佈圖表
0.04w simulation
Al2O3-PbSn-2mi(4balls) 67.0973 1002.43 AlN-Au-8mi-4vias(6balls)
with mold compound
58.175 779.38
表 4-17 同軸式高頻封裝設計前後
溫度及Rja（Junction-air-resistance）分佈圖表
0.04w simulation
Al2O3-PbSn-2mi 63.278 906.95
AlN-Au-8mi-4Vias With copper lid and length 2500micros 100 Thickness 10 counts aluminum heat sink
55.0625 31.7284 118.21
( )
c圖 1-1 IC 元件在封裝型態上的發展與演進[3]
圖 1-2 IC 元件在引腳的發展與演進[3]
Temperature Humidity 55%
19%
Dust 6%
Vibration 20%
圖 1-3 引起電子元件損壞的主要因素[1]
圖1-4 IC構裝的四大功能
(來源:Microelectronics Packaging Handbook)
圖 1-5電子構裝的層級區分[4]
圖 1-6 構裝技術的演進[3]
圖 1-7 不同覆晶的型態[4]
圖 1-8 以錫球凸塊接合的覆晶[4]
圖1-9 傳統式高頻元件覆晶封裝俯視圖
圖 1-10 傳統式高頻元件覆晶封裝側視圖
圖 1-11 傳統式高頻覆晶晶片實體
圖 1-12 同軸式覆晶結構封裝俯視圖
圖 1-13 同軸式覆晶結構封裝側視圖
圖 1-14 自然對流下 FC-BGA 散熱量的分佈[14]
圖 1-15 各種型態的散熱裝置[19]
圖 1-16 底部填膠示意圖[4]
圖1-17熱沈(Heat sink)示意圖(1)
圖1-18熱沈(Heat sink)示意圖(2)
圖1-19 熱界面材料(Thermal Interface Material)
圖 1-20 FC-BGA 熱傳方向
圖 2-1 ICEPAK 求解流程圖[26]
圖 2-2 物理模式示意圖
T1 T2
k Y
k
fY
f s s∂
= ∂
∂
∂ θ θ
T3 T4
T5 T6
圖 2-3 介面能量守衡示意圖
圖 2-4 FC-BGA 熱阻示意圖
圖 3-1 數值方法流程示意圖[26]
圖 3-2 不同形式之網格切割
圖 3-3 二維三角格點[26]
圖 3-4 Assembly 非均勻分部網格功能
圖 4-1 傳統式高頻覆晶元件模擬網格測試
圖 4-2 同軸式高頻覆晶元件模擬網格測試
圖 4-3 傳統式高頻覆晶封裝球格設計 Junction-air-Resistance 圖表
圖 4-4 傳統式高頻覆晶封裝球格設計 Junction-board-Resistance 圖表
圖 4-5 傳統式高頻覆晶封裝材料設計變更 Junction-air-Resistance 圖表
圖 4-6 傳統式高頻覆晶封裝材料設計變更 Junction-board-Resistance 圖表
圖 4-7 傳統式高頻覆晶封裝
線路厚度設計變更 Junction-air-Resistance 圖表
圖 4-8 傳統式高頻覆晶封裝線路厚度設計變 Junction-board-Resistance 圖表
圖 4-9 傳統式高頻覆晶封裝熱通道設計變更 Junction-air-Resistance 圖表
圖 4-10 傳統式高頻覆晶封裝熱通道設計變更 Junction-board-Resistance 圖表
圖 4-11 同軸式高頻覆晶封裝材料設計變更 Junction-air-Resistance 圖表
圖 4-12 同軸式高頻覆晶封裝材料設計變更 Junction-board-Resistance 圖表
圖 4-13 同軸式高頻覆晶封裝線路厚度設計變 Junction-air-Resistance 圖表
圖 4-14 同軸式高頻覆晶封裝線路厚度設計變更 Junction-board-Resistance 圖表
圖 4-15 同軸式高頻覆晶封裝熱通道設計變更 Junction-air-Resistance 圖表
圖 4-16 同軸式高頻覆晶封裝熱通道設計變更 Junction-board-Resistance 圖表
圖 4-17 傳統式高頻覆晶外部點膠式封裝設計
圖 4-18 傳統式高頻覆晶外部點膠式等效體積封裝設計
圖 4-19 傳統式高頻覆晶外部點膠式 等效體積封裝設計溫度分佈圖
圖 4-20 傳統式高頻覆晶外部點膠式等效
體積封裝設計溫度分佈圖(有填入空氣)
圖 4-21 同軸式高頻覆晶封裝在晶片上方 不同型式的散熱裝置之設計
Type.0 No enhancement Type.1 With heat spreader
Type.2 With heat spreader and soft pad Type.3 With metallic lid
Type.4 With mold compound
(varying percentage of converage,25%)
Type.7 With metallic and heat sink
Type.5 With mold compound
(varying gap in the mold compound)
Type.6 With mold compound and Cu heat spreader
(varying gap between the die and the heat spreader)
圖 4-22 同軸式高頻覆晶封裝外部各設計
之 Rja（Junction-air-resistance）分佈圖表
圖 4-23 同軸式高頻覆晶封裝外部各設計晶片上方 熱傳量所佔整體散熱部分之百分比
圖 4-24 同軸式高頻覆晶封裝當熱沈散熱座邊長為 1500µm 鳍片各數為 5 時在不同風速下平均溫度分佈圖表
圖 4-25 同軸式高頻覆晶封裝當熱沈散熱座邊長為 1500µm 鳍片各數為 10 時在不同風速下平均溫度分佈圖表
圖 4-26 同軸式高頻覆晶封裝當熱沈散熱座邊長為 2500µm 鳍片各數為 5 時在不同風速下平均溫度分佈圖表
圖 4-27 同軸式高頻覆晶封裝當熱沈散熱座邊長為 2500µm 鳍片各數為 10 時在不同風速下平均溫度分佈圖表
圖 4-28 同軸式高頻覆晶封裝當熱沈散熱座邊長為 2500µm 鳍片各數為 15 時在不同風速下平均溫度分佈圖表
圖 4-29 滯流現象對溫度分佈的影響圖
2500-2500-10-5-31.7284 2500-2500-15-5-31.8652
圖 4-30 滯流現象對速度分佈的影響圖