Effect Of Laser Microtexture Hydrophilic-hydrophobic Channel On Heat Dissipation Of Micro Heat Pipe

In recent years,microelectronics technology has developed rapidly,and microheat pipes have become the ideal components for heat dissipation of microelectronic products due to their high thermal conductivity,fast thermal response,and good isothermal properties.The heat transfer performance of the micro heat pipe mainly depends on the liquid absorption structure in the tube,and the liquid absorption core manufactured by the traditional process and method can no longer adapt to the current development trend of thin and thin electronic equipment.In order to improve the current restrictions of the heat pipe liquid absorption core,this article uses laser micro The texture technology prepares a flat micro heat pipe with affinity and hydrophobic spacing channels.The spacing channels have the effect of improving the transport capability of droplets,thereby improving the heat transfer performance of the heat pipe.main tasks as follows:(1)Through microscopic morphological observation,combined with the principle of laser microtexture processing,the laser microtexture mechanism of the superhydrophilic and superhydrophobic functions of copper plates was analyzed.The forming mechanism of super-hydrophilic and super-hydrophobic is mainly the effect of light and heat.The surface of the molten matrix sputtered by the vaporization pressure forms a nanoburr-like structure.Due to its high surface energy,the structure has super-hydrophilic properties;after heat treatment,The burr-like structure is fine,and the burr structure forms a uniform boss structure on the surface,which forms an air cushion between the droplet and the substrate,that is,the wensel state is formed,which has super-hydrophobic properties.(2)Suitable laser process parameters are:average power 70W,pulse width 240ns,repetition frequency 74kHz,scanning speed 1002mm/s.Under this process parameter,the contact angle of the super-hydrophilic region is 0°.After heat treatment,the super-pro Water turns into super-hydrophobic with a contact angle of 161.2°.(3)Analyze the mechanism of rapid droplet transport in the affinity and hydrophobic separation channels.Processed super-hydrophilic and super-hydrophobic interval channels of different widths,and tested the liquid transport time of different widths.The channel with a width of 2mm had the shortest transport time,and the fastest average transport speed was calculated to be 18.56mm/s.Compared with all super-hydrophilic samples,the average speed of transportation increased by 2.5 times.(4)The flat micro heat pipe with a size of 100×30×2mm~3was assembled,and the size of the enclosed space was 96×26×1mm~3.The material of the micro heat pipe shell,the type of working medium,and the liquid filling rate were selected.After the laser preparation of the affinity and hydrophobic spacing channels,the processing of the vacuum injection tube,the assembly bonding and packaging,and the air tightness test,the process was completed.The preparation of experimental samples of micro-heat pipe with affinity and hydrophobic space channels for heat transfer performance test.(5)An experimental platform for heat transfer performance of micro heat pipes was built,and the suitable filling rate of this kind of heat pipes was first measured to be 50%.Then at 50%liquid filling rate,the effect of the channel width on the heat dissipation of the heat pipe is detected,and the start time,operating temperature,and heat dissipation performance of the micro heat pipe with an interval channel of 2 mm are better.Compared with the sample without interval,the start time Increased by 34.89%,the surface temperature decreased by 9.1%,the surface temperature of the heating plate decreased by 9.6%,and has a faster thermal response.