Thermal Analysis Method To Layout Level Of Intergrated Circuit

Because of the development trend of very large scale integrated circuit which is higher integration, SOC and higher work frequency, people pay more attention to reliability of circuit. Due to the increase of component density, the decrease of the feature size and the improving of operating speed of integrated circuit, the power density, which directly induces temperature rise, increases rapidly. The influence which is brought by thermal problem to ICs is more serious. The increase of power consumption and temperature do lead to decrease of performance and reliability of ICs. More than 50% of all IC failures are related to thermal issues. So the studies of thermal problems of ICs are more significant.Combining circuit simulation tools Cadence Spectre and a well established commercial simulation program based on finite element method ANSYS, this paper calculates 3D layout-level steady thermal analysis of an amplifier by building a thermal modeling with the help of LinkCAD for ANSYS.ANSYS can not be applied to the very large scale integrated circuits because of the complicated model and large calculation amount, so we introduce a new method to thermal analysis of layout level ofICs.In this paper, a new method which combines SKILL language with equivalent-thermal resistance method is presented. The analysis of steady-state thermal simulation of analog circuit designed by Cadence design software is made by this method. Electronic parameters and equivalent thermal resistances of devices can be obtained by Cadence circuit simulation software and finite element analysis software-ANSYS. Then the temperature rise of the device in circuit can be calculated. Combining location message obtained by SKILL programming with the temperature rise of device, temperature distribution graph is found. Semi-automatization of thermal analysis process of ICs layout level is obtained. And thermal analysis process \of VLSI layout level is accomplished.