This paper proposes a synthesis of different electrical methods used to estimate the temperature of power semiconductor devices. The following measurement methods are introduced: the voltage under low current levels, the threshold voltage, the voltage under high current levels, the gate-emitter voltage, the saturation current, and the switching times. All these methods are then compared in terms of sensitivity, linearity, accuracy, genericity, calibration needs, and possibility of characterizing the thermal impedance or the temperature during the operation of the converter. The measurement of thermo-sensitive parameters of wide bandgap semiconductors is also discussed.

/pdf/temperature-measurement-of-power-semiconductor-devices-by-1nz3bww95c.pdf

Temperature Measurement of Power Semiconductor Devices by Thermo-Sensitive Electrical Parameters—A Review

Self-heating in AlGaN/GaN device structures was probed using integrated micro-Raman/Infrared (IR) thermography. IR imaging provided large-area-overview temperature maps of powered devices. Micro-Raman spectroscopy was used to obtain high-spatial-resolution temperature profiles over the active area of the devices. Depth scans were performed to obtain temperature in the heat-sinking SiC substrate. Limitations in temperature and spatial resolution, and relative advantages of both techniques are discussed. Results are compared to three-dimensional finite-difference simulations

Integrated micro-Raman/infrared thermography probe for monitoring of self-heating in AlGaN/GaN transistor structures

This paper proposes an in situ diagnostic and prognostic (D&P) technology to monitor the health condition of insulated gate bipolar transistors (IGBTs) used in EVs with a focus on the IGBTs' solder layer fatigue. IGBTs' thermal impedance and the junction temperature can be used as health indicators for through-life condition monitoring (CM) where the terminal characteristics are measured and the devices' internal temperature-sensitive parameters are employed as temperature sensors to estimate the junction temperature. An auxiliary power supply unit, which can be converted from the battery's 12-V dc supply, provides power to the in situ test circuits and CM data can be stored in the on-board data-logger for further offline analysis. The proposed method is experimentally validated on the developed test circuitry and also compared with finite-element thermoelectrical simulation. The test results from thermal cycling are also compared with acoustic microscope and thermal images. The developed circuitry is proved to be effective to detect solder fatigue while each IGBT in the converter can be examined sequentially during red-light stopping or services. The D&P circuitry can utilize existing on-board hardware and be embedded in the IGBT's gate drive unit.

https://www.eprints.ncl.ac.uk/file_store/production/205942/6F226411-CD74-45E2-A9D6-401F58E2A259.pdf

In Situ Diagnostics and Prognostics of Solder Fatigue in IGBT Modules for Electric Vehicle Drives

The measurement of the junction temperature with thermosensitive electrical parameters (TSEPs) is largely used by electrical engineers or researchers, but the obtained temperature value is generally not verified by any referential information of the actual chip temperature distribution. In this paper, we propose to use infrared (IR) measurements in order to evaluate the relevance of three commonly used TSEPs with insulated gate bipolar transistor chips: the saturation voltage under a low current, the gate-emitter voltage, and the saturation current. TheIR measurements are presented in detail with an estimation of the emissivity of the black paint deposited on the power module. The temperatures obtained with IR measurements and with the different TSEPs are then compared in two cases: the use of only one chip and the use of two paralleled chips.

/pdf/comparison-of-junction-temperature-evaluations-in-a-power-4p3nwn5uk1.pdf

Comparison of Junction Temperature Evaluations in a Power IGBT Module Using an IR Camera and Three Thermosensitive Electrical Parameters

The conventional $RC$ -lumped thermal networks are widely used to estimate the temperature of power devices, but they lack of accuracy in addressing detailed thermal behaviors/couplings in different locations and layers of the high-power insulated gate bipolar transistor (IGBT) modules. On the other hand, a finite-element (FE)-based simulation is the other method, which is often used to analyze the steady-state thermal distribution of IGBT modules, but it is not possible to be used for a long-term analysis of load profiles of power converter, which is needed for reliability assessments and better thermal design. This paper proposes a novel 3-D $RC$ -lumped thermal network for the high-power IGBT modules. The thermal coupling effects among the chips and among the critical layers are modeled, and boundary conditions, including the cooling conditions, are also considered. It is demonstrated that the proposed thermal model enables both accurate and fast temperature estimation of high-power IGBT modules in the real loading conditions of the converter while maintaining the critical details of the thermal dynamics and thermal distribution. The proposed thermal model is verified by both the FE-based simulation and the experimental results.

/pdf/a-3-d-lumped-thermal-network-model-for-long-term-load-1g4shcvyai.pdf

A 3-D-Lumped Thermal Network Model for Long-Term Load Profiles Analysis in High-Power IGBT Modules

There are numerous methods for measuring the temperature of an operating semiconductor device. The methods can be broadly placed into three generic categories: electrical, optical, and physically contacting. The fundamentals underlying each of the categories are discussed, and a review of the variety of techniques within each category is given. Some of the advantages and disadvantages as well as the spatial, time, and temperature resolution are also provided.

D.L. Blackburn

Papers

Temperature measurements of semiconductor devices - a review