Design And Manufacture Of The Flexible Woven Heat Sink And Study Of Its Performance

In view of the limited heat dissipation space of highly integrated and miniaturized electronic devices,traditional heat sinks are difficult to adapt to complex and limited workspace.As a porous medium,metal woven materials have flexible deformation and adjustable pore structure.They have obvious advantages in solving the heat dissipation problem of electronic devices in limited space.However,there are few studies on the application and performance optimization of metal woven materials in the field of device heat dissipation.In this paper,the flexible woven heat sink is designed and manufactured with sintered copper woven material as the main body.The heat dissipation characteristics of the flexible woven heat sink are experimentally studied and optimized,and it's applied to the heat dissipation of LED lamp.The main works are as follows:(1)The numerical model of metal woven materials is established,and the structural statics of plain-woven and twill-woven structures are simulated,and the stress-strain characteristics of different woven structures under load are analyzed.A multi-layer woven structure model is established to simulate the flow and heat transfer.The effects of different inlet velocity and void fraction of woven structure on the flow characteristics,pressure drop characteristics and heat transfer characteristics are studied.(2)Preparing copper woven braids according to the structure parameters optimized by simulation,sintering copper woven braids at different sintering temperature and holding time.By testing the basic properties of sintered copper woven braids,such as tensile properties,bending properties and thermal conductivity,the optimum sintering parameters of copper woven braids are obtained as sintering temperature 850? and holding time 1h.On this basis,the optimum sintering parameters are obtained for the design and manufacture of flexible woven heat sink.(3)The temperature measuring systems under natural convection and forced convection are designed and built.The structural parameters,input power,ambient temperature,extrusion deformation and wind speed of the array and bundle woven heat sinks are systematically studied and analyzed to obtain the optimal structure and performance parameters of the flexible woven heat sink.The experimental results show that the cooling range of the heat source of the array woven heat sink is 13.3% under the expanding extrusion mode,and the optimum expanding form of the bundle woven heat sink is type II(?=25°~90°,?=25°~40°),which shows the prominent advantage of maintaining efficient heat dissipation in limited space.(4)The flexible woven heat sink is applied to the LED headlamp with vibration test,dust test and interior chamber test.The test results meet the requirements of the headlamp.The test results of optical parameters show that with the increase of input current,the light flux increases and the light efficiency decreases gradually.The light flux and light efficiency of the headlamp with type II is higher than that with type I.