Effective thermal modeling of a thin film snubber resistor for power modules

Abstract

This paper proposes an effective thermal compact modeling method for a thin film resistor that is dedicated for snubber circuits in power electronic modules. The objective compact model consists of thermal capacitors and thermal resistors. Some of the objective compact models express the effects of local air gaps as well as convective boundary conditions, which are natively non-linear phenomena. To identify their values, we use the surface temperature response of the thin film resistor to the input power. The experimental results show that the derived compact thermal model robustly causes the measured thermal durability to wide input power pulse width variations to reappear.

A thermally optimizing method of thin film resistor trimming with machine learning

“…The experiments are conducted by electro-thermal simulation to verify effectiveness as well as correctness of the proposed method. An experimented NiCr resistor model is based on an industrial RNP-20S [41], which electro-thermal behavior has been verified by measurements [12]. The film thicknesses are varied 141 nm, 151 nm, 161 nm, and 171 nm.…”

“…The typical conventional method of L-cut trimming is achieved in the following steps: 1) Trim vertically to the maximum depth obtained experimentally by pulse durability tests [12]. 2) Trim horizontally while monitoring the resistance between the terminal electrodes, from the previous point to the point where the monitored resistance value matches the target value.…”

“…Here, we set the power consumption of the NiCr thin film resistor to 1000 W against 35 W of the actual rating power, in order to research destruction at over-voltage. In the conventional method, the maximum temperature exceeds 1440 • C, the fusing temperature of the NiCr film [12] at 141nm of the thickness. As shown in Fig.…”

“…It leads to more energy-efficient as well as more reliable power modules. Our earlier study indicates that the NiCr thin-film resistors are thermally destructed by the high power pulse input [12]. Reducing the maximum temperature rise during the opera-tion provides higher power durability.…”