Thermal simulation apparatus and thermal simulation method

Abstract

We provide a thermal simulation system that can perform transient thermal simulations with low computational load and high accuracy. [Solution] A thermal simulation apparatus 1 performs transient thermal simulation with a power semiconductor module 30 connected to a heat sink 50 via a thermal interface material 40 as the subject of analysis. The apparatus comprises a model construction unit 11 that individually constructs a first model 101, which is a Cauer model of the thermal equivalent circuit of the power semiconductor module 30, and a second model 102, which is a Cauer model of the thermal equivalent circuits of the thermal interface material 40 and the heat sink 50, based on the specifications of the subject of analysis. An analysis unit 12 performs transient thermal simulations of the first model 101 and the second model 102 individually, and also performs transient thermal simulations of the second model by using the amount of heat dissipation, which is the output of the lowest stage of the thermal equivalent circuit of the first model 101, as the input to the thermal equivalent circuit of the second model.

Claims

1. A thermal simulation device that performs transient thermal simulations with a power semiconductor module connected to a heat sink via a thermal interface material as the target of analysis, Based on the specifications of the object to be analyzed, a model construction unit constructs a first model, which is a Cauer model of the thermal equivalent circuit of the power semiconductor module, and a second model, which is a Cauer model of the thermal interface material and the heat sink, separately. A thermal simulation apparatus characterized by having an analysis unit that performs transient thermal simulations of the first model and the second model separately, and uses the amount of heat dissipated, which is the output of the lowest stage of the thermal equivalent circuit of the first model, as the input to the thermal equivalent circuit of the second model to perform transient thermal simulations of the second model.

2. In claim 1, If the power semiconductor module has a first power semiconductor element and a second power semiconductor element, the model construction unit individually constructs, as the first model, a third model which is a Cauer model of the thermal equivalent circuit of the power semiconductor module with the first power semiconductor element as the heat source, and a fourth model which is a Cauer model of the thermal equivalent circuit of the power semiconductor module with the second power semiconductor element as the heat source. The thermal simulation apparatus is characterized in that, when the power semiconductor module has a first power semiconductor element and a second power semiconductor element, the analysis unit performs transient thermal simulations of the third model and the fourth model, calculates the total heat dissipation amount by summing the heat dissipation amounts which are the outputs of the lowest stage of the thermal equivalent circuits of the third model and the fourth model, and uses the total heat dissipation amount as the input to the thermal equivalent circuit of the second model to perform transient thermal simulations of the second model.

3. In claim 2, A thermal simulation apparatus characterized in that the first power semiconductor element is an IGBT, and the second power semiconductor element is a diode connected in antiparallel to the IGBT.

4. In claim 1, The thermal simulation apparatus is characterized in that the model building unit has a model conversion unit that converts the Foster model of the thermal equivalent circuit of the power semiconductor module into a Cauer model.

5. In claim 1, An input unit that receives input of the specifications of the object to be analyzed, A storage unit that stores the specifications of the object to be analyzed, A thermal simulation apparatus characterized by having an output unit that outputs the results of a transient thermal simulation performed by the analysis unit.

6. In claim 5, The thermal simulation apparatus is characterized in that the output unit has a display unit that displays the results of the transient thermal simulation performed by the analysis unit.

7. A thermal simulation method for performing transient thermal simulations with a power semiconductor module connected to a heat sink via a thermal interface material as the target of analysis, Based on the specifications of the object to be analyzed, a first model, which is a Cauer model of the thermal equivalent circuit of the power semiconductor module, and a second model, which is a Cauer model of the thermal interface material and the heat sink, are constructed separately. A thermal simulation method characterized by performing transient thermal simulations of the first model and the second model separately, and using the amount of heat dissipated, which is the output of the lowest stage of the thermal equivalent circuit of the first model, as the input to the thermal equivalent circuit of the second model to perform the transient thermal simulation of the second model.

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