Embedded Microchannel Heat Sink Based On PCB Process And Its Heat Transfer Capacity

With the improvement of manufacturing technology in microelectronics industry,electronic devices such as chip on board are developing towards integration and miniaturization.With this trend,the heat of electronic devices such as chips continues to increase.If the heat is not dissipated in time,it will affect the device and even the whole system.Therefore,heat dissipation has become the primary problem in the field of microelectronics.At present,most of the heat dissipation methods for electronic devices use external heat sinks,which have the disadvantages of large size,heavy weight and difficulty in integrating with on-board devices.Microchannel heat sink(MCHS)has great development prospects due to its advantages of large specific surface area,strong heat transfer capacity,and easy integration with the system.Therefore,this thesis will study the heat dissipation on the board in combination with the microchannel heat sink.To solve the above problems,this thesis proposed and implemented the principle and structure of embedded microchannel heat sink based on printed circuit board(PCB)process for heat dissipation of electronic devices such as on-board chips.The main research works and results of this thesis mainly include:(1)The working principle and structure of embedded MCHS based on PCB technology for heat dissipation of chips and other electronic devices were proposed and studied.The heat transfer capacity of MCHS was analyzed,the thermal resistance model of MCHS was established,and the thermal resistance of microchannel heat sink with nickel plating and no nickel plating was compared.The results show that the nickel layer improves the heat conduction and convective heat transfer intensity with the fluid,so as to reduce the overall thermal resistance.After nickel layer is added,the MCHS has strong heat dissipation capacity.(2)The effects of channel length,microchannel width and rib width on the heat dissipation performance of embedded MCHS in fluid solid thermal coupling physical field were studied by finite element method.The heat transfer performance and flow performance of the designed rectangular structure(type I),rectangular segmented structure(type II),S-shaped structure(type III)and rectangular structure with hexagonal liquid collecting area(type IV)were analyzed.Type I has the best performance in heat transfer,Type IV has the best performance in terms of flow.(3)The processing technology of embedded MCHS integrated on PCB was studied.The FR4 substrate is obtained by PCB process,and then the whole embedded MCHS is assembled by machining,electroplating and welding.(4)The heat dissipation performance of MCHS was tested and analyzed.The heat dissipation performance and pressure drop of four structures were tested.Type I structure performs best and type IV structure is the worst.Finally,the thermal performance coefficient was introduced.When considering heat transfer and flow,type I structure still shows the best performance.The research work of this thesis is conducive to promote the development of heat dissipation technology for electronic devices such as chips,and provides a new idea for realizing on-board heat dissipation.