UC Irvine

The increasing power density of smartphone chipset urges the demand of high-heat-flux removal techniques. Convetionally, smartphone manufacturers used aluminimum, copper, and graphene sheet to spread the heat generated by the chipset. However, the specific heat capcity of those material limits the chip power dissipation. A vapor chamber, which takes advantages of the specific heat capcity and the latent heat of fluid, can increase the limit of the chipset power dissipation. This work performs experimental and computational studies to investigate factors that affect the vapor chamber thermal conductivity. It has been found that the vapor chamber can be affected by gravity, porosity of the porous media, pore size of the porous media, surface energy of the interal structure, and boundary conditions. Gravity helps the liquid phase flow back to the evaporator. Porosity and pore size of the porous media can enhance the capillary pressure and postpone the boiling nucleation. The surface energy of the interal structure can force the nucleation sites at evaporator section. The understanding of these factors can pave a way for designing a vapor chamber.