MCM温度场稳态分析报告.docx
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MCM温度场稳态分析报告
题目四：
MCM温度场稳态分析
多芯片组件加散热器〔热沉〕的冷却分析
图1（a）、图1（b）所示分别为大功率球栅阵列MCM的截面图和俯视图，五个芯片采用倒装焊方式置于有机基板上，为了增加模块的散热能力，在芯片背面上加一热扩展面。
表1所示为各材料的物理属性。
模型的热边界条件为：
热源为芯片的功耗，其中ASIC大芯片的功耗为2W，热流密度为×106W/m3；其余的四个芯片中，三个微处理器芯片功率的功耗为W，热流密度为×106W/m3；存储器芯片的功耗为0.8W，热流密度为×106W/m3。
模型外部〔热扩展面、基板、PCB〕通过与空气的对流进展散热，在空气自然对流情况下，周围空气的温度为20oC，对流换热系数为15W/（m2·K）。
表4.1MCM结构参数和材料属性
模型组件
材料
尺寸〔mm〕
导热系数
〔W/（m·k）〕
芯片
硅
；
82
芯片凸点
5Sn/95Pb
7×7，6×6，，
36
基板
Al2O3+BeO
20
焊料球
33
PCB
FR4
热介质材料
导热脂
1
粘接剂
粘接剂
热扩展面
铜
390
分析
从而导致器件性能变化和可靠性的下降。
热场分析和设计是MCM设计中一个重要的环节[3]。
MCM器件中的热应力来自两个方面，即来自MCM模块内部和MCM模块所处的外部环境所形成的热应力，这些热应力都会影响到器件的电性能、工作频率、机械强度和可靠性。
随着MCM集成度的提高和体积的缩小,尤其是对于集成了大功率芯片的MCM,其内部具有多个热源，热源之间的热耦合作用较强，单位体积内的功耗很大，由此带来的芯片热失效和热退化现象突出。
有资料明确,器件的工作温度每升高10oC，其失效率增加1倍[4]。
因此,准确模拟大功率MCM模块的三维温度场分布，并分析掌握其热特性，有利于指导MCM热设计方案的选择，对提高大功率MCM的可靠性具有重要意义。
本文针对某球栅阵列封装的大功率MCM，提出了一种简化的热学模型，并利用有限元方法,借助有限元通用程序ANSYS,对其进展三维温度场的稳态模拟和分析。
方案步骤如下：
1、建模：
图4-1MCM几何模型图
图4-2MCM网格划分图
2、施加载荷计算
a、初始温度与对流系数〔施加于模型外外表，即与空气接触的部位〕
图4-3施加载荷后分析图
b、分析处理（温度云图）结果如下：
图4-4温度云图
3、后处理：
图4-5热沉的芯片内部温度分布云图
图4-6芯片凸点〔5Sn/98Pb〕温度分布
图4-7基板〔聚酰亚胺〕温度分布云图
图4-8焊料球〔37Sn/63Pb〕温度分布云图
图4-9PCB（FR4）温度分布云图
图4-10热扩展面〔铜〕温度分布云图
4简要分析
从以上的分析结果可以得出：
最高温度出现在中间大芯片区域，MCM内部有源功率芯片是热源的主要贡献者，芯片产生的热量主要沿芯片背面方向传递；加散热装置来对大功率MCM进展降温是一种直接有效的方式；另外，在一样条件下，合理的结构布局，如防止大功率器件过分集中不仅能降低结点温度最大值，而且能防止热集中现象，提高MCM组件的可靠性。
针对球栅阵列封装的大功率MCM其内部具有多个热源、耦合作用强、内部发热量大、温度高的特点，建立其热学模型，在ANSYS平台下对其进展了稳态模拟分析；结果明确，增加外部散热装置可以大大降低MCM的温度，是对其进展降温最直接有效的一种方式；合理布局可以防止热集中现象。
5结论
在MCM器件内部，热场对器件的性能和可靠性有严重的影响，热场分析是MCM设计中的重要环节。
利用ANSYS软件对一球栅阵列的MCM进展了模拟分析，结果明确：
1）多芯片组件中,大功率芯片为模块中热源的主要贡献者,芯片内最高温度点位于中间大芯片区域。
2）MCM几种降低温度的方法：
加外部散热装置是一种直接有效的对MCM进展降温方式（有散热装置的最高温度是134.186oC，没有散热的布局温度大概达350oC）；在一样条件下，合理的结构布局，能降低结点温度最大值，提高MCM组件的可靠性。
命令流
/BATCH
WPSTYLE,,,,,,,,0
/FILNAME,homework4,0
/TITLE,3D_analysisofMCMheatdissipation
/PREP7
ET,1,SOLID70
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,KXX,1,,82
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,KXX,2,,36
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,KXX,3,,20
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,KXX,4,,33
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,KXX,5,,8.37
MPDATA,KYY,5,,8.37
MPDATA,KZZ,5,,0.32
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,KXX,6,,1
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,KXX,7,,1.1
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDE,KXX,6
MPDATA,KXX,6,,1
MPTEMP,,,,,,,,
MPTEMP,1,0
MPDATA,KXX,8,,390
BLOCK,0,0.05,0,0.05,0,0.0015,
BLOCK,0,0.02,0,0.02,0.0019,0.0034,
BLOCK,0,0.02,0,0.02,0.00355,0.00505,
BLOCK,0,0.017,0,0.017,0.00355,0.0044,
VSBV,3,4
BLOCK,0,0.004,0,0.004,0.0036,0.00425,
BLOCK,0,0.0025,0.0085,0.0135,0.0036,0.00425,
BLOCK,0.0085,0.0135,0,0.0025,0.0036,0.00425,
SPH4,0.000635,0.000635,0.0003
BLOCK,0,0.001,0,0.001,0.0002,0.0006,
BLOCK,0,0.001,0,0.001,-0.0002,-0.0006,
FLST,3,2,6,ORDE,2
FITEM,3,8
FITEM,3,-9
VSBV,7,P51X
NUMCMP,VOLU
FLST,3,1,6,ORDE,1
FITEM,3,7
VGEN,13,P51X,,,0.00127,,,,0
FLST,3,13,6,ORDE,2
FITEM,3,7
FITEM,3,-19
VGEN,13,P51X,,,,0.00127,,,0
SPH4,0.000275,0.000275,0.00015
BLOCK,0,0.001,0,0.001,0.0001,0.0006,
BLOCK,0,0.001,0,0.001,-0.0001,-0.0006,
FLST,3,2,6,ORDE,2
FITEM,3,177
FITEM,3,178
VSBV,176,P51X
FLST,3,1,6,ORDE,1
FITEM,3,179
VGEN,5,P51X,,,0.00075,,,,0
FLST,3,5,6,ORDE,2
FITEM,3,176
FITEM,3,-180
VGEN,5,P51X,,,,0.00075,,,0
FLST,3,1,6,ORDE,1
FITEM,3,179
VGEN,2,P51X,,,0.00875,,,,0
FLST,3,1,6,ORDE,1
FITEM,3,201
VGEN,6,P51X,,,0.00075,,,,0
FLST,3,6,6,ORDE,2
FITEM,3,201
FITEM,3,-206
VGEN,3,P51X,,,,0.00075,,,0
FLST,3,1,6,ORDE,1
FITEM,3,179
VGEN,2,P51X,,,,0.00875,,,0
FLST,3,1,6,ORDE,1
FITEM,3,219
VGEN,6,P51X,,,,0.00075,,,0
FLST,3,6,6,ORDE,2
FITEM,3,219
FITEM,3,-224
VGEN,3,P51X,,,0.00075,,,,0
BLOCK,0.017,0.02,0,0.017,-0.0001,0.00005,
BLOCK,0,0.02,0.017,0.02,-0.0001,0.00005,
wpoff,0,0,0.00075
BLOCK,0,0.004,0,0.004,0,0.00015,
BLOCK,0.0085,0.0135,0,0.0025,0,0.00015,
BLOCK,0,0.0025,0.0085,0.0135,0,0.00015,
WPAVE,0,0,0
CSYS,0
wpoff,0,0,0.00505
BLOCK,0,0.02325,0,0.02325,0,0.0015,
BLOCK,0.02175,0.02325,0,0.02325,0.0015,0.0085,
FLST,3,1,6,ORDE,1
FITEM,3,243
VGEN,8,P51X,,,-0.003,,,,0
VSEL,S,LOC,Z,0.00505,0.02
FINISH
/SOL
FINISH
/PREP7
FLST,2,9,6,ORDE,2
FITEM,2,242
FITEM,2,-250
VADD,P51X
VSEL,S,LOC,Z,0.0034,0.00425
VSEL,U,,,5
FLST,2,2,6,ORDE,2
FITEM,2,195
FITEM,2,216
VDELE,P51X,,,1
ALLSEL,ALL
FLST,2,240,6,ORDE,7
FITEM,2,1
FITEM,2,-194
FITEM,2,196
FITEM,2,-215
FITEM,2,217
FITEM,2,-241
FITEM,2,251
VGLUE,P51X
VDELE,249,,,1
VSEL,S,LOC,Z,0,0.0015
CM,_Y,VOLU
VSEL,,,,250
CM,_Y1,VOLU
CMSEL,S,_Y
CMSEL,S,_Y1
VATT,5,,1,0
CMSEL,S,_Y
CMDELE,_Y
CMDELE,_Y1
VSEL,S,LOC,Z,0.0015,0.0019
FLST,5,169,6,ORDE,2
FITEM,5,7
FITEM,5,-175
CM,_Y,VOLU
VSEL,,,,P51X
CM,_Y1,VOLU
CMSEL,S,_Y
CMSEL,S,_Y1
VATT,4,,1,0
CMSEL,S,_Y
CMDELE,_Y
CMDELE,_Y1
VSEL,S,LOC,Z,0.0019,0.0034
CM,_Y,VOLU
VSEL,,,,252
CM,_Y1,VOLU
CMSEL,S,_Y
CMSEL,S,_Y1
VATT,3,,1,0
CMSEL,S,_Y
CMDELE,_Y
CMDELE,_Y1
VSEL,S,LOC,Z,0.0034,0.00425
VSEL,S,LOC,Z,0.0034,0.0036
FLST,5,2,6,ORDE,2
FITEM,5,195
FITEM,5,244
CM,_Y,VOLU
VSEL,,,,P51X
CM,_Y1,VOLU
CMSEL,S,_Y
CMSEL,S,_Y1
VATT,7,,1,0
CMSEL,S,_Y
CMDELE,_Y
CMDELE,_Y1
FLST,5,2,6,ORDE,2
FITEM,5,195
FITEM,5,244
VSEL,U,,,P51X
FLST,5,59,6,ORDE,6
FITEM,5,176
FITEM,5,-194
FITEM,5,196
FITEM,5,-215
FITEM,5,217
FITEM,5,-236
CM,_Y,VOLU
VSEL,,,,P51X
CM,_Y1,VOLU
CMSEL,S,_Y
CMSEL,S,_Y1
VATT,2,,1,0
CMSEL,S,_Y
CMDELE,_Y
CMDELE,_Y1
VSEL,S,LOC,Z,0.0036,0.00425
FLST,5,3,6,ORDE,2
FITEM,5,246
FITEM,5,-248
CM,_Y,VOLU
VSEL,,,,P51X
CM,_Y1,VOLU
CMSEL,S,_Y
CMSEL,S,_Y1
VATT,1,,1,0
CMSEL,S,_Y
CMDELE,_Y
CMDELE,_Y1
CM,_Y,VOLU
VSEL,,,,245
CM,_Y1,VOLU
CMSEL,S,_Y
CMSEL,S,_Y1
VATT,8,,1,0
CMSEL,S,_Y
CMDELE,_Y
CMDELE,_Y1
VSEL,U,,,245
FLST,5,3,6,ORDE,3
FITEM,5,216
FITEM,5,242
FITEM,5,-243
CM,_Y,VOLU
VSEL,,,,P51X
CM,_Y1,VOLU
CMSEL,S,_Y
CMSEL,S,_Y1
VATT,6,,1,0
CMSEL,S,_Y
CMDELE,_Y
CMDELE,_Y1
VSEL,S,LOC,Z,0.0036,0.00425
SMRT,6
SMRT,7
MSHAPE,1,3D
MSHKEY,0
FLST,5,3,6,ORDE,2
FITEM,5,246
FITEM,5,-248
CM,_Y,VOLU
VSEL,,,,P51X
CM,_Y1,VOLU
CHKMSH,'VOLU'
CMSEL,S,_Y
VMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
VSEL,S,LOC,Z,0.0034,0.00355
SMRT,8
CM,_Y,VOLU
VSEL,,,,244
CM,_Y1,VOLU
CHKMSH,'VOLU'
CMSEL,S,_Y
VMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
CM,_Y,VOLU
VSEL,,,,195
CM,_Y1,VOLU
CHKMSH,'VOLU'
CMSEL,S,_Y
VMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
VSEL,S,LOC,Z,0.0019,0.0034
CM,_Y,VOLU
VSEL,,,,252
CM,_Y1,VOLU
CHKMSH,'VOLU'
CMSEL,S,_Y
VMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
VSEL,S,LOC,Z,0,0.0015
CM,_Y,VOLU
VSEL,,,,250
CM,_Y1,VOLU
CHKMSH,'VOLU'
CMSEL,S,_Y
VMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
VSEL,S,LOC,Z,0.00425,0.0044
SMRT,7
FLST,5,3,6,ORDE,3
FITEM,5,216
FITEM,5,242
FITEM,5,-243
CM,_Y,VOLU
VSEL,,,,P51X
CM,_Y1,VOLU
CHKMSH,'VOLU'
CMSEL,S,_Y
VMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
SMRT,8
CM,_Y,VOLU
VSEL,,,,245
CM,_Y1,VOLU
CHKMSH,'VOLU'
CMSEL,S,_Y
VMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
VSEL,S,LOC,Z,0.0034,0.0036
FLST,5,2,6,ORDE,2
FITEM,5,195
FITEM,5,244
VSEL,U,,,P51X
SMRT,6
FLST,5,59,6,ORDE,6
FITEM,5,176
FITEM,5,-194
FITEM,5,196
FITEM,5,-215
FITEM,5,217
FITEM,5,-236
CM,_Y,VOLU
VSEL,,,,P51X
CM,_Y1,VOLU
CHKMSH,'VOLU'
CMSEL,S,_Y
VMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
VSEL,S,LOC,Z,0.0015,0.0019
SMRT,7
FLST,5,169,6,ORDE,2
FITEM,5,7
FITEM,5,-175
CM,_Y,VOLU
VSEL,,,,P51X
CM,_Y1,VOLU
CHKMSH,'VOLU'
CMSEL,S,_Y
VMESH,_Y1
CMDELE,_Y
CMDELE,_Y1
CMDELE,_Y2
ALLSEL,ALL
VSEL,S,LOC,Z,0.0034?
0.00425
VSEL,S,LOC,Z,0.0036,0.00425
ASEL,S,EXT
FLST,5,65,5,ORDE,65
FITEM,5,17
FITEM,5,21
FITEM,5,30
FITEM,5,32
FITEM,5,36
FITEM,5,38
FITEM,5,719
FITEM,5,723
FITEM,5,727
FITEM,5,730
FITEM,5,735
FITEM,5,739
FITEM,5,743
FITEM,5,747
FITEM,5,751
FITEM,5,755
FITEM,5,759
FITEM,5,763
FITEM,5,767
FITEM,5,771
FITEM,5,775
FITEM,5,779
FITEM,5,783
FITEM,5,787
FITEM,5,791
FITEM,5,799
FITEM,5,803
FITEM,5,807
FITEM,5,811
FITEM,5,815
FITEM,5,819
FITEM,5,823
FITEM,5,827
FITEM,5,831
FITEM,5,835
FITEM,5,839
FITEM,5,843
FITEM,5,847
FITEM,5,851
FITEM,5,855
FITEM,5,859
FITEM,5,863
FITEM,5,867
FITEM,5,871
FITEM,5,875
FITEM,5,883
FITEM,5,887
FITEM,5,891
FITEM,5,895
FITEM,5,899
FITEM,5,903
FITEM,5,907
FITEM,5,911
FITEM,5,915
FITEM,5,919
FITEM,5,923
FITEM,5,927
FITEM,5,931
FITEM,5,935
FITEM,5,939
FITEM,5,943
FITEM,5,947
FITEM,5,951
FITEM,5,955
FITEM,5,959
ASEL,U,,,P51X
FINISH
/SOL
FLST,2,4,5,ORDE,4
FITEM,2,15
FITEM,2,19
FITEM,2,23
FITEM,2,1066
/GO
SFA,P51X,1,CONV,240,240
FLST,2,8,5,ORDE,8
FITEM,2,29
FITEM,2,31
FITEM,2,33
FITEM,2,35
FITEM,2,37
FITEM,2,39
FITEM,2,1064
FITEM,2,-1065
/GO
SFA,P51X,1,CONV,250,250
VSEL,S,LOC,Z,0.0019,0.0034
ASEL,S,EXT
WPSTYLE,,,,,,,,1
FLST,5,3,5,ORDE,3
FITEM,5,1071
FITEM,5,1073
FITEM,5,1075
ASEL,R,,,P51X
FLST,2,1,5,ORDE,1
FITEM,2,1075
/GO
SFA,P51X,1,CONV,15,20
VSEL,S,LOC,Z,0.0019,0.0034
ASEL,S,EXT
FLST,5,2,5,ORDE,2
FITEM,5,10
FITEM,5,1072
ASEL,R,,,P51X
FLST,2,2,5,ORDE,2
FITEM,2,10
FITEM,2,1072
/GO
SFA,P51X,1,CONV,15,20
VSEL,S,LOC,Z,0,0.0015
ALLSEL,ALL
VSEL,S,LOC,Z,0,0.0015
ASEL,S,EXT
FLST,5,2,5,ORDE,2
FITEM,5,3
FITEM,5,5
ASEL,U,,,P51X
ALLSEL,ALL
VSEL,S,LOC,Z,.?
0.0015
VSEL,S,LOC,Z,0,0.0015
ASEL,S,EXT
FLST,5,2,5,ORDE,2
FITEM,5,3
FITEM,5,5
ASEL,U,,,P51X
FLST,5,169,5,ORDE,169
FITEM,5,40
FITEM,5,44
FITEM,5,
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