Optimal micro heat pipe configuration on high performance heat spreaders.

摘要

The purpose of this research was to determine the optimal micro heat pipe (MHP) configuration on high performance heat spreaders. The ultimate goal was to reduce the spreading resistance and eliminate localized hot spots. Hot spots occur when the temperature is not evenly distributed throughout an area. To reduce these hot spots, an array of micro heat pipes was implemented into the heat spreader. Seven array configurations, ranging from 2 MHPs to 8 MHPs, were evaluated for a range of power inputs varying from 3 W to 21 W. The finite element software, MECHANICA 4.0, was utilized for the simulations. Through a comprehensive literature review, it was determined that evaluating the MHP limitations and finding an effective thermal conductivity were beyond the scope of this research. Therefore, a simplified equation was used for the MHP limitations, and the simulations were carried out for conductivities of 5,000 W/m°C, 50,000 W/m°C, and 100,000 W/m°C. The convective boundary condition was also varied to determine its effect on spreading resistance.;It was determined that the spreading resistance was independent of the convection coefficient and power input for a specific MHP effective thermal conductivity. The spreading resistance decreased with increasing effective thermal conductivities until the conductivity reached about 50,000 W/m°C, at which point the spreading resistance leveled off. The spreading resistance was found to decrease with increasing numbers of MHPs in the array. Overall, MHPs did aid in decreasing the spreading resistance.