Cooling of Chips in Circuit Boards Problem One

Cooling of Chips in Circuit Boards

Problem • One way to cool chips mounted on circuit boards is to encapsulate the boards in metal frames that provide efficient pathways for conduction to supporting cold plates. • Heat Generated by the chips is then dissipated by transfer to water flowing through passages drilled in the plates.

Design/Specifications Coolant Passages water Coolant Passages • D=10 mm, N= 10 Circuit Board Frames AIR • T=47 degree Celsius Cold Plate T = 32 Celsius Water • Initial temperature = 7 Celsius • Mass flow rate = 0. 2 kg/s Cold Plate • T= 32 degrees Celsius Air Circuit Board Frames. T=47 Celsius, N=10 Circuit Board Containing Chips • P = 1 atm • V= 10 m/s • T = 7 degrees

Assumptions • Isothermal cold plate • All heated generated by circuit boards is dissipated by cold plates • Circuit boards may be represented as isothermal at an average surface temperature. • Air flow over circuit boards approximates that over a flat plate in parallel flow. • Part A: To find how much heat is dissipated by the circuit boards • Part B: To find how much of the heat generated by the circuit boards is transferred to air

Part A With a total of N = 10 passages, the total heat dissipation is 50. 2 k. W

Part B To find how much of the heat generated by the circuit boards is transferred to air. 2, 670 W 9. 5 percent(low) Heat Transfer to the Air

Results • Air not effect for Cooling Microchips • The cooling capacity of the cold plates far exceeds that of the air flow. However, the challenge would be one of efficiently transferring such a large amount of energy to the cold plates without incurring excessive temperatures on the circuit boards

Equations Used