Design And Optimization Of Microchannel Structure Based On LTCC

With the development of electronic product towards miniaturization, high performance and multi-function, the package density is improved constantly. The unit area power is increased continuously, which leads to the higher package temperature. High temperature causes the reduction of the chip performance, the burnout of device and the fracture of connecting line. The great temperature difference results in the fracture of package and the exfoliation of chip. Therefore, the heat dissipation has become a core problem restricting chip package. The monolayer microchannel structure, which is based on low temperature co-fired ceramic(LTCC), is studied and optimized in this paper.Six structures of monolayer microchannel such as parallel, serpentine, spiral, curve, H-type and tree-type are simulated with ANSYS based on the study of microchannel at home and abroad.The effect of the microchannel structure, the water flow rate and the chip power on the substrate temperature, velocity and pressure distribution is discussed in detail. The heat emission efficiencies of different microchannels are evaluated. The impacts of the flow rate at the entrance and the chip power variations on the heat emission are analyzed.To satisfy the requirement of higher density packaging and the substrate temperature evenness, two optimized schemes are proposed on the basic of the monolayer microchannel structure in this paper, which are with bilayer structure and with embedded copper. The effects of the microchannel structure, the water flow rate and the chip power on the substrate temperature, velocity and pressure distribution are studied, by modeling and simulating the two structures. Moreover, the optimization microchannels are researched in comparison with the monolayer microchannel, and the improved overall performance is evaluated.Finally, the effect of the substrate material on the heat emission efficiency is studied. The substrate temperature of microchannel based on high temperature co-fired ceramic(HTCC) and Si, is simulated and compared with that based on LTCC which shows that the material plays an important role on the heat emission. How the internal microchannel structure, including the size of the channel and the shape of the channel corner, affects the heat emission efficiency and fluid motion laws are also analyzed briefly in this paper.