Experimental Investigation on the Vapor Chambers with Sintered Copper Powder Wick

High power electronics units generate high-density heat flux, which poses a significant threat to the reliability of these devices. The vapor chamber (VC) has a very high heat transfer rate and has a wide range of applications in the heat dissipation of electronic products. VCs with sintered copper powder wicks sized as irregular shape copper powder 50 mu m (I-50 mu m), I-75 mu m, I-110 um, I-150 mu m were studied in this paper. The effect of liquid filling ratio was discussed. The results indicated that the thermal resistance of all VCs decreased with the increase of heating power. The capillary performance of wick was the dominant factor for the heat transfer performance of VCs with different kinds of wick. A capillary performance factor was proposed to evaluate the capillary performance of VCs. The capillary performance factor of VC with the wick of I-75 mu m was much higher than that of the other types of VC in this study. The heat source surface temperature of VCs could be affected by filling ratio and wick structure. But, it should be insensitive to the filling ratio when a better capillary performance factor was obtained. With the same heating area and similar structure, the maximum heat flux density of the VC would decrease as the height of vapor cavity decreased.

Automated summary

The research showed that the thermal resistance of VC decreases with increasing heating power and the capillary performance of the wick is crucial for heat transfer. A capillary performance factor was proposed to evaluate VC performance, with VC equipped with I-75 μm wick demonstrating superior performance. Additionally, the filling ratio and structure can impact the heat source surface temperature of VCs.