Performance test of an ultra-thin flat heat pipe with a 0.2 mm thick vapor chamber

Abstract

In this paper, a novel ultra-thin flat heat pipe (UFHP) with an active steam chamber of 76 × 46 × 0.2 mm 3 is successfully designed, fabricated and tested. The innovation point of the UFHP is its thinner thickness with only 0.65 mm total thickness which can reduce the space for heat dissipation in electronic devices and accommodate its increasingly compact structure. Another innovation point is the design of supporting pillars. It is etched in the UFHP to avoid the ultra-thin chamber deformation and can also supply vertical channels for liquid reflux. Thermal performance is assessed and results reveal that the optimal operating power of the UFHP is 7.1-13.7 W at different tilt angles and liquid filling rates. When the filling rate is 1.05 and the tilt angle is 90 degrees, it has the best performance, and the minimum average thermal resistance is 1.15 °C W −1 with the input power varying from 7.1 to13.7 W. When the input power is 15.9 W and the evaporator temperature is 60 °C, the heat transfer performance of the vertically placed UFHP is perfect and with a thermal conductivity of 800 W m −1 K −1 . This research is of great significance for the production of UFHP with ultra-thin thickness and good heat transfer performance.

A Numerical Analysis on the Effect of Deviation From a Centered Wick Structure in an Ultra-Thin Flattened Heat Pipe

“…The increase in Tv,II caused an increase in the thermal resistance between the evaporator and condenser sections, resulting in a decrease in the thermal performance of heat pipe. The height of the vapor flow channel within the recent ultra-thin heat pipe was 0.2 mm (Shi et al, 2019). Thus, in the fabrication process of ultra-thin heat pipes, pinpoint accurate positioning of the wick structure is essential to avoid an unnecessary increase in thermal resistance.…”

“…Among them, in recent years, an attention has been paid on ultra-thin heat pipes for thermal management of thin electronics devices. Recently, Shi et al (2019) fabricated an 80-mm-long, 50-mm-wide, and 0.65-mm-thick ultra-thin heat pipe. The height of the vapor flow channel within the heat pipe was 0.2 mm.…”

Deployment of vapour chambers for electronic heat dissipation: state-of-the-art

“…So for large mesh sizes, the wick has larger capillary pressure and lower liquid permeability. 93,104 Table 4 illustrates some of the studies conducted by the researchers using the screen mesh wick. The screen mesh wick VC is used particularly in the case of thin and ultrathin VC.…”

Thermal performance of wickless and orientation independent thin vapor chambers with wettability patterned micro structure

“…It could work at the heat load of 7.9 W, with a thermal resistance of 4.2 K/W. Shi et al [9] designed a #200 copper screen mesh on the bottom sheet of an 80 mm × 50 mm × 0.65 mm UTVC. The thermal resistance was ~1.2 K/W in the range of heat load of 7.1 W ~ 13.7 W. Chen et al [10] bonded a #300 copper screen mesh on the bottom sheet as wick structure and micro pillar arrays on upper sheet as support structure, and the size of the UTVC was 104 mm × 14 mm × 0.4 mm.…”