FVTX at Power Outa ge 1 FVTX Substrate FEA during Power Outage C. M. Lei October 06, 2006
Jan 18, 2016
FVTX at Power Outage 1
FVTX Substrate FEAduring Power Outage
C. M. Lei
October 06, 2006
FVTX at Power Outage 2
Goals
• To use FEA as a design tool to understand if the module and substrate are structurally safe during power outage
FVTX at Power Outage 3
The Layup of the Multi-chip Module
Substrate (.12 cf + .38 tpg + .12 cf = .62 mm)
FVTX at Power Outage 4
FEA Model
Half Modules with 4 chips
(took advantages of symmetry and all modules evenly positioned)
Bump bond layer were modeled as a continous layer with adjusted properties based on an area ratio 21.33 (with eutectic solder bond diameter 0.035 mm assumed).
Effective Heat flux from ROC = 5.868 mW/mm^2Effective heat flux from sensor = 0.25 mW/mm^2Total heat load = 2.8W for half model
Cooling contact area 5mm wide at +7C
FVTX at Power Outage 5
Material Library Used in this FEA
70 # # 292080 # # 343290 # # 3784
100 # # 3984150 # # 3624200 # # 2600250 # # 1960
273.2 # # 1784300 # # 1600350 # # 1352400 # # 1168500 # # 904600 # # 744
Temp in K K in W/m-K
All materials were assumed to be isotropic with constant properties except - TPG in which the thermal conductivity varies- Anisotropic carbon fiber facing and bump bonds
Young’s modulus E, MPa
Poison’s ratio Thermal k, w/m-K
CTE
HDI 30e3 0.30 0.26 17e-6
Silicone glue 2 0.36 0.24 100e-6
Silicon sensor 110e3 0.30 141 2.6e-6
Silicon ROC 110e3 0.30 141 2.6e-6
TPG 83e3 0.20 table -1e-6
Eutectic solder 32e3 0.051 24.7e-6
TPG Thermal K
Carbon fiber 0/90facing:Einplane = 1.48e5 Mpa, Eout-of-plane =7445 Mpa, kinplane = 55.85 W/mK, kout-of-plane = 0.69 W/mK, ainplane = -0.04e-6 ppm/K, aout-of-plane
=30.17e-6 ppm/KEutectic solder bump bond layer: Ex = Ez = 0.15 Mpa, Ey = 1500 Mpa, kx = kz = 0.33e-3 W/mK, ky = 2.38 W/mK, a = 24.7e-6 ppm/K
FVTX at Power Outage 6
When heat load = 0, Temperature everywhere is equal to the coolant temperatue at +7C
Heat Load = 0W , Half Model with 4 chips
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mm7oC COOLING AT ENDS, POWER OUTAGE with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 7
When heat load = 0, Temperature everywhere at +7CMax resultant disp. = 86.8 micronsMax displacement of silicon = 55.3 mircons
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mm7oC COOLING AT ENDS, POWER OUTAGE with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 8
Stress Z Plot (out-of-plane 900direction)
TPG LayerMax Resultant Stress = 2.5 MpaMax Stress_Z = 0.1 Mpa
Flexural Strenth = 36.7 Mpa Z = 38.5 Mpa //
Tensile Strength < 0.69 Mpa Z = 6,897 Mpa //
OK!
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mm7oC COOLING AT ENDS, POWER OUTAGE with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 9
Stress Z Plot (out-of-plane 900direction)
OK!
Carbon Fiber LayerMax Resultant Stress = 5.3 MpaMax Stress_Z = 0.1 Mpa
Flexural Strenth = 669 Mpa 00
Tensile Strength =1950 Mpa 00
= 28 Mpa 900
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mm7oC COOLING AT ENDS, POWER OUTAGE with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 10
OK!
Silicone Glue Layers between HDI and Substrate and between HDI and Module
Max Stress = 0.07 Mpa
Strength_NEE001 = 1.1 Mpa
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mm7oC COOLING AT ENDS, POWER OUTAGE with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 11
OK!
HDI Layer
Max Stress = 4.9 Mpa
Tensile Strength_Kapton = 166 MpaTensile Strength_Copper = 320 MPa
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mm7oC COOLING AT ENDS, POWER OUTAGE with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 12
OK!
Sensor and ROC Layers
Max Stress = 3.3 Mpa
Strength_Si = 120 MPa
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mm7oC COOLING AT ENDS, POWER OUTAGE with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 13
Bump Bond Layer
Strength of eutect solderTensile Yield = 43 MpaUltimate = 52 MPa
Max resultant stress = 0.383*21.33 = 8.2 Mpa
OK!
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mm7oC COOLING AT ENDS, POWER OUTAGE with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 14
Max resultant disp. = 128 micronsMax displacement of silicon = 81.4 mircons
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 15
Stress Z Plot (out-of-plane 900direction)
TPG LayerMax Resultant Stress = 3.7 MpaMax Stress_Z = 0.17 Mpa
Flexural Strenth = 36.7 Mpa Z = 38.5 Mpa //
Tensile Strength < 0.69 Mpa Z = 6,897 Mpa //
OK!
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 16
Stress Z Plot (out-of-plane 900direction)
OK!
Carbon Fiber LayerMax Resultant Stress = 7.7 MpaMax Stress_Z = 0.15 Mpa
Flexural Strenth = 669 Mpa 00
Tensile Strength =1950 Mpa 00
= 28 Mpa 900
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 17
OK!
Silicone Glue Layers between HDI and Substrate and between HDI and Module
Max Stress = 0.11 Mpa
Strength_NEE001 = 1.1 Mpa
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 18
OK!
HDI Layer
Max Stress = 7.2 Mpa
Tensile Strength_Kapton = 166 MpaTensile Strength_Copper = 320 MPa
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 19
OK!
Sensor and ROC Layers
Max Stress = 4.8 Mpa
Strength_Si = 120 MPa
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 20
Bump Bond Layer
Strength of eutect solderTensile Yield = 43 MpaUltimate = 52 MPa
Max resultant stress = 0.564*21.33 = 12.0 Mpa
OK!
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at 0oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 21
Max resultant disp. = 245 micronsMax displacement of silicon = 156 mircons
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at -20oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 22
Stress Z Plot (out-of-plane 900direction)
TPG LayerMax Resultant Stress = 7.1 MpaMax Stress_Z = 0.3 Mpa
Flexural Strenth = 36.7 Mpa Z = 38.5 Mpa //
Tensile Strength < 0.69 Mpa Z = 6,897 Mpa //
OK!
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at -20oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 23
Stress Z Plot (out-of-plane 900direction)
OK!
Carbon Fiber LayerMax Resultant Stress = 14.8 MpaMax Stress_Z = 0.29 Mpa
Flexural Strenth = 669 Mpa 00
Tensile Strength =1950 Mpa 00
= 28 Mpa 900
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at -20oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 24
OK!
Silicone Glue Layers between HDI and Substrate and between HDI and Module
Max Stress = 0.21 Mpa
Strength_NEE001 = 1.1 Mpa
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at -20oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 25
OK!
HDI Layer
Max Stress = 13.7 Mpa
Tensile Strength_Kapton = 166 MpaTensile Strength_Copper = 320 MPa
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at -20oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 26
OK!
Sensor and ROC Layers
Max Stress = 9.3 Mpa
Strength_Si = 120 MPa
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at -20oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 27
Bump Bond Layer
Strength of eutect solderTensile Yield = 43 MpaUltimate = 52 MPa
Max resultant stress = 1.08*21.33 = 23.0 Mpa
OK!
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at -20oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 28
Max resultant disp. = 76.9 micronsMax displacement of silicon = 49 mircons
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at +35oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 29
Stress Z Plot (out-of-plane 900direction)
TPG LayerMax Resultant Stress = 2.2 MpaMax Stress_Z = 0.07 Mpa
Flexural Strenth = 36.7 Mpa Z = 38.5 Mpa //
Tensile Strength < 0.69 Mpa Z = 6,897 Mpa //
OK!
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at +35oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 30
Stress Z Plot (out-of-plane 900direction)
OK!
Carbon Fiber LayerMax Resultant Stress = 4.6 MpaMax Stress_Z = 0.2 Mpa
Flexural Strenth = 669 Mpa 00
Tensile Strength =1950 Mpa 00
= 28 Mpa 900
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at +35oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 31
OK!
Silicone Glue Layers between HDI and Substrate and between HDI and Module
Max Stress = 0.07 Mpa
Strength_NEE001 = 1.1 Mpa
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at +35oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 32
OK!
HDI Layer
Max Stress = 4.3 Mpa
Tensile Strength_Kapton = 166 MpaTensile Strength_Copper = 320 MPa
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at +35oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 33
OK!
Sensor and ROC Layers
Max Stress = 2.9 Mpa
Strength_Si = 120 MPa
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at +35oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 34
Bump Bond Layer
Strength of eutect solderTensile Yield = 43 MpaUltimate = 52 MPa
Max resultant stress = 0.339*21.33 = 7.2 Mpa
OK!
RESULTS WITH CF/TPG/CF SUBSTRATE 0.62 mm (0.12+0.38+0.12) mmNo coolant flow, Power Outage with Surrounding Temperature at +35oCSubstrate Glue: 2 Mpa silicone; Module Glue: 2 Mpa silicone
FVTX at Power Outage 35
Temperature Settings
Exposed Temperature, C any 0 -20 35
Coolant temperature, C 7 n/a n/a n/a
Temperature Differential caused the cte mismatch, C -14 -21 -41 14
FEA Resultant Displacements
Overall Displacement, microns 87 128 245 -77
Silicon Displacement, microns 55 81 156 -49
FEA Resultant Stress in Mpa
Material Layer Strength, Mpa
TPG, in plane 6897 2.5 3.7 7.1 2.2
TPG, out of plane 0.69 0.10 0.17 0.30 0.07
Carbon Fiber, axial 1950 5.3 7.7 14.8 4.6
Carbon Fiber, lateral 28 0.1 0.2 0.3 0.2
Silicone Glue 1.1 0.07 0.11 0.21 0.07
HDI, effective 166 4.9 7.2 13.7 4.3
Silicon 120 3.3 4.8 9.3 2.9
Bump Bond, effective 43 8.2 12.0 23.0 7.2
Summary of Results
FVTX at Power Outage 36
Remarks
• when power supply to chips is off but coolant is still running, substrate and modules are all in coolant temperture 7C . This is bascially independent on surrounding temperature. (if possible, the coolant temperature should be set back to room temperature to eliminate any thermal effects.)
• When power supply to chips is off and coolant is not running, substrate and modules are all basically at the same temperature as of the surrounding.
• All stresses were within the tensile range when surrounding temperature was between -20C and +35C.
• FEAs were done based on an assumption that a compliant low-modulus (E = 2 Mpa) adhesive can be used. Results would be different if the final choice of adhesives are different.