Download - GTK Micro Channel Frame
GTK Micro Channel Frame
Thermal layout
Georg Nüßle
GTK Cooling Meeting 2
Content
December 2, 2011
• Model thermal frame (simulation)
• Layout channel geometry (analytical)
GTK Cooling Meeting 3
Content
December 2, 2011
• Model thermal frame (simulation)
• Layout channel geometry (analytical)
GTK Cooling Meeting 4
Geometry and Boundaries
December 2, 2011
• Cooling frame with sensor and chips
GTK Cooling Meeting 5
Geometry and Boundaries
December 2, 2011
• Cooling frame with sensor and chips
• Cut through complete assembly
GTK Cooling Meeting 6
Geometry and Boundaries
December 2, 2011
• Cooling frame with sensor and chips
• Cut through complete assembly
• ASIC digital part 6mm long• That means micro channel
area 6mm wide6mm
GTK Cooling Meeting 7
Geometry and Boundaries
December 2, 2011
• Cooling frame with sensor and chips
• Cut through complete assembly
• ASIC digital part 6mm long• That means micro channel
area 6mm wide• Simplified model: half
model, slice of 1mm• Cover wafer 100µm thick• MC wafer 400µm thick• Channel height 300µm• Channel width 100µm• Wall width between
channels 100µm
GTK Cooling Meeting 9
Geometry and Boundaries
December 2, 2011
Fixed temperature on channel walls, -20°C (Junction Temperature)
Heat source: digital 4W/cm2, analog 0.5W/cm2
Glue between ASIC and mc frame, 0.3W/m/K
Bonding between cover and mc wafer
Symmetry, front, back and right side
Bump bonds, ASIC and Sensor, 0.12W/m/K • SnAG3.5 -> 33W/m/K • Pixel area 300µm x 300µm, bump diameter 20µm• Area ratio gives 0.12W/m/K for contiguous material
GTK Cooling Meeting 10
Temperature Distribution
December 2, 2011
ASIC 100µm thick
-3.2837°C
~ -12.6°C
ASIC 200µm thick
-7.0151°C
~ -14.2°C
∆T over Sensor ~ 9.3°C
∆T over Sensor ~ 7.2°C
GTK Cooling Meeting 11
Total Deformation
December 2, 2011
ASIC 200µm thick, fixed by symmetry boundary condition on the right side
Maximum Deformation ~ 3µm
ASIC 200µm thick, fixed by symmetry boundary condition on the right side and by gluing on the PCB (Fixed support)
Maximum Deformation ~ 32µm
Symmetry boundary conditionFixed support boundary condition
GTK Cooling Meeting 13
Thermal Stress
December 2, 2011
ASIC 200µm thick, fixed by symmetry boundary condition on the right side
Maximum Stress ~ 12.1MPa
ASIC 200µm thick, fixed by symmetry boundary condition on the right side and by gluing on the PCB (Fixed support)
Maximum Stress ~ 65.7MPa
Symmetry boundary conditionFixed support boundary condition
GTK Cooling Meeting 15
Content
December 2, 2011
• Model thermal frame
• Layout channel geometry (analytical)
GTK Cooling Meeting 16
Constraints
December 2, 2011
• Channel length 60mm• Width cooled area 6mm• ∆T between inlet and
outlet 5K (-> m, ∆p)• Junction temperature = ∆TJ
between wall and mean fluid temperature
• ∆TJ depends on geometry and heat flux60mm
• K takes into account the ratio between the hydraulic area and the heat exchange area in a square shaped channel
∆TJ
GTK Cooling Meeting 17
Influence of the Wall Width
December 2, 2011
wall width channel depth channel width DTJunction Dpchannel
[µm] [µm] [µm] [K] [bar]50 250 100 4,472 2,33
100 250 100 5,962 3,11200 250 100 8,943 4,66
• Smaller walls lead to more channels and more heat exchange surface• ∆Tjunction and ∆pchannel rise with the wall width
GTK Cooling Meeting 18
∆TJ and ∆p with 50µm wall
December 2, 2011
channel width [µm]
∆TJ / ∆pin_out
[K] / [bar]
0 50 100 150 200 250 3000
2
4
6
8
10
12
14
16
18
20
channel height 350µmchannel height 250µm
∆pin_out
∆TJ
GTK Cooling Meeting 19
∆TJ and ∆p with 100µm wall
December 2, 2011
channel width [µm]
0 50 100 150 200 250 3000
2
4
6
8
10
12
14
16
18
20
channel height 350µmchannel heigth 250µm
∆TJ / ∆pin_out
[K] / [bar]
∆pin_out
∆TJ
GTK Cooling Meeting 20
∆TJ and ∆p with 200µm wall
December 2, 2011
channel width [µm]
0 50 100 150 200 250 3000
2
4
6
8
10
12
14
16
18
20
channel height 350µmchannel heigth 250µm
∆TJ / ∆pin_out
[K] / [bar]
∆pin_out
∆TJ
