The Research And Development Of Multi-Physics Coupling Algorithm For Three-Dimensional High-Density Integrated System

With the development of society, automotive electronics, aerospace industry, communications, computers and other modern industries need more powerful, smaller in size, and higher degree of integration of the portable electronic products. From DIP play MCM, the area of utilization, frequency, and reliability in Single-chip structure has become higher. But the Single-chip structure still remain in the two-dimensional structure model, and can not meet the modern needs of the industry. Therefore, higher density multilayer stack structure model have been proposed. As the density increases, the adverse impact of temperature on the chip has become more important. Due to the higher complexity and power density, the effect of temperature on the multilayer stack structure is greater. So, the thermal management is necessary, and need a accurately and efficiently three-dimensional thermal analytical model. The main work of this dissertation is described as following:(1) The thermal resistance has been established based on the theory of the Fourier heat conduction and convection theory. Chip structure is divided into a plurality of regions reasonably. The thermal resistance of each region is calculated, and the sum resistance of x, y and z is obtained. Based on that, the temperature of the hottest-spotin the heat source and the average temperature of the boundary are obtained. Since the three-dimensional temperature diffusivity is similar to the ball wall thermal conductivity, so the temperature distribution is calculated based on that. The three-dimensional thermal analytical basic model has been established, including a heat center temperature model, the temperature distribution model and the iterative algorithm. The thermal model of single-layer structure and multilayer stack structure have developed from three-dimensional thermal analytical basic model, and the thermal resistance analysis chart is ploted. For the analysis of the thermal resistance of thermal convection, the coefficient of convectionis calculated based on iterative algorithm.(2) The result of ANSYS simulation is used as the verification standard to verify the correctness of the three-dimensional thermal analytical model. The thermal parameters of the three-dimensional analytical model is used in ANSYS simulation, such as the pover and he coefficient of convection. The error of the maximum temperature is less than 10%, and that of the temperature distribution within 20%. The results show the accuracy of the three-dimensional analytical model.(3) The experimental test of a dedicated chip has been conducted, and result has been compared with the result of the three-dimensional thermal analytical model and theANSYS simulation. The error of the experiment and the analytical model is less than 10%, and that of experiment and ANSYS simulation within 10%. The results show the accuracy of the three-dimensional analytical model.(4) In order to improve the efficiency, the computer-aided analysis has been used in the simulation of thermal modeling. The thermal analysis software has been developed based on Windows and VC++. The software has the friendly interface, simple operation, portability, and high precision. It will play aimportant role in the thermal design of multilayer chip stacked structure.The three-dimensional thermal analytical model is suitable for single and multi-chip structure. It is able to obtain the corresponding temperature distribution quickly and effectively. The validity of the analytical model has been verified by ANSYS simulation and experimental test. In the Single-chip structure and multilayer structure stacked chip designing, the three-dimensional thermal analytical model is with certain reference value for thermal design.