Analysis%20of%20PC%20Chip%20Heat%20Sink%20Design

1
Analysis of PC Chip Heat Sink Design

• Royce Tatton
• ME 340
• Dr. Solovjov
• Fall 2006

2
The Problem

• Problem 3.137 in Incropera and DeWitt
• Comparison of two fin arrays to be used as PC
  chip heat sink
• Which provides more heat transfer (better
  cooling)?

3
The Chip

• Material Ceramic Porcelain
• Dimensions 53 X 57 X 10 mm
• Temperature 75 C Maximum

4
Design A

• Dimensions 3 X 3 X 30 mm
• Number 6 X 9 array (54 total)
• Material 6061 Aluminum
• Convection Coefficient 125 W/m2K

5
Design B

• Dimensions 1 X 1 X 7 mm
• Number 14 X 17 array (238 total)
• Material 6061 Aluminum
• Convection Coefficient 375 W/m2K

6
Methods

• Use COSMOSWorks 2006 to determine maximum flux
  and temperature distribution in Design A and
  Design B
• Compare to analytical results

7
Setup of Problem

• Simplify by reducing to ¼ of the total geometry
  along symmetry planes
• Apply temperature constraints to chip surfaces
• Apply convection loads to top chip surface and
  fins

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Results Design A

• Maximum chip temperature of 75C (348.15 K)
• Resultant heat flux of 7.807E5 W/m2

Temperature Plot
Heat Flux Plot
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Results Design B

• Maximum chip temperature of 75C (348.15 K)
• Resultant heat flux of 1.002E6 W/m2
• Design B provides greater cooling of chip

Temperature Plot
Heat Flux Plot
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Conclusions

• Design B provides better cooling to the chip
• Results agree with the results of the problem in
  the textbook
• Conduction coefficient very significant factor
• Bigger is not always better

11
Recommendation

• Always perform heat transfer analysis before
  making decision on intuition
• Further analysis with radiation and other
  materials to find a better fin design