Ultra thin vapor chamber cooling technology for high-power electronic cooling
The development of electronic technology has greatly promoted the miniaturization and high-performance integration of electronic devices, but has instead led to an increase in waste heat from electronic chips, and the thermal management challenges of high-power electronic devices are gradually intensifying. Vapor Chamber (VC) is widely used as a heat dissipation device in electronic devices such as smartphones, laptops, and communications. It utilizes the latent heat of vaporization of the working liquid to carry away a large amount of heat, while the capillary driving force of the internal capillary structure ensures the circulation of the working liquid. As a two-phase heat dissipation device, VC has always been widely studied in scientific research and the market.
The ultra-thin vapor chamber (UTVC) consists of an evaporator plate, a condenser plate, and a capillary core, with a thickness of 0.5mm. The capillary core has a shape similar to sunflowers, with a thickness of 1mm, and is composed of an inner core and an outer core. The inner core is made of a copper mesh with an outer diameter of 35mm and a 300 mesh, which consists of 18 gas overflow and liquid reflux channels, as well as a capillary core with an inner diameter of 15mm. The outer core refers to the inner core and is made of a channel capillary core with an outer diameter of 70mm. The shape of the capillary structure is completed by wire cutting and laser cutting processes.
The radial gradient layered capillary core has an interval cavity channel as the gas overflow channel, the capillary channel as the channel for liquid reflux, the inner core of the fine copper mesh can provide capillary force for liquid reflux, and the outer core of the coarse copper mesh can reduce liquid reflux resistance and improve permeability. The inner and outer cores of the radial gradient layered capillary core are cut and sintered on the evaporator plate. The evaporator and condenser plates are diffusion welded to connect the capillary core to the condenser, while also supporting the internal cavity. High frequency welding is used to weld the injection tube, and finally, through the reduction process, vacuum pumping and liquid injection are carried out. The entire process is already very mature in the heat pipe support process.
A comparative analysis of thermal performance between UTVC and copper plates of the same geometric size was conducted, describing the changes in heat source temperature and thermal resistance under different power consumption. Compared to copper plates, UTVC has higher heat transfer performance and a more uniform temperature distribution within the test power consumption range, especially in high power consumption. The Qmax of UTVC is 420W (187.6W/cm2), the minimum thermal resistance is 0.0531 ℃/W (360W), and the thermal resistance is reduced by 59.2%. More widely used in the field of high-power electronic cooling.
