Power Semiconductor Module Damage Estimation via Dynamic Thermal Model

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Solution Overview

Problem

Power semiconductor modules face mechanical stress due to thermal expansion mismatch between materials, leading to potential failure, especially in critical applications like electric vehicles and offshore windmills, where maintenance costs are high and access is limited.

Innovation Solution

A method and device for estimating the level of damage or lifetime expectation of power semiconductor modules using a dynamic thermal model with on-line degradation localization, employing a Cauer thermal model and low-cost sensors to detect temperature changes and power losses, allowing for precise identification of degradation and localization within the module.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If dynamic updating of thermal model with on-line degradation localization is implemented, then measurement precision and reliability are improved, but device complexity increases

Engineering Contradiction:
Improvedamage level estimation accuracyVSAvoidthermal model complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements dynamic updating of the thermal model during operation, allowing the model parameters to change over time based on measured temperature data. This enables the system to adapt to degradation processes while maintaining measurement precision without requiring a completely new complex system

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses measured temperature data from the power semiconductor module to continuously update and refine the thermal model parameters. This feedback mechanism improves measurement precision by adapting the model to actual conditions while using a relatively simple update algorithm rather than complex real-time computation

Inventive Principle:
Principle #23Feedback

2Reliability

If dynamic updating of thermal model with on-line degradation localization is implemented, then reliability is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvemodule reliabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The system performs self-diagnosis by using its own temperature measurements to update its thermal model and detect degradation. This self-service capability improves reliability without requiring additional external diagnostic equipment or complex manufacturing processes

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent monitors changes in thermal model parameters over time to detect degradation. By focusing on parameter evolution rather than requiring complex structural modifications, the system improves reliability while maintaining ease of manufacture

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If location of degradation is identified through thermal model parameters, then measurement precision is improved, but loss of information increases

Engineering Contradiction:
Improvedegradation localization precisionVSAvoidinformation feedback to manufacturer
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The system provides feedback about degradation location and extent to the manufacturer, enabling them to improve future designs. The feedback mechanism preserves critical information while using the thermal model to precisely locate degradation without losing valuable diagnostic data

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables accurate prediction of remaining useful life, enabling just-in-time maintenance, reducing maintenance costs, and improving the design of next-generation modules by providing real-time health monitoring and quality control.

Implementation Method 1

one or several power semiconductor dies are mechanically, thermally, and electrically attached to a substrate... thermal expansion mismatch between the different materials in the structure... mechanical stress is created

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3203250B1Method and device for estimating a level of damage or a lifetime expectation of a power semiconductor module
Publication Date: 2023.05.24 MITSUBISHI ELECTRIC R&D CENTRE EUROPE BV
  • EP3203250B1 patent drawingFigure 1~2
  • EP3203250B1 patent drawingFigure 3~4
  • EP3203250B1 patent drawingFigure 5

AI summary

The present invention concerns a method and a device for estimating a level of damage or a lifetime expectation of a power semiconductor module comprising at least one die that is mechanically, thermally, and electrically attached to a substrate, composed of plural layers of different materials. The invention: - obtains power losses of the power semiconductor module, - obtains the temperature in at least two different locations of the power semiconductor module, - estimates a thermal model between the at least two different locations of the power semiconductor module using the determined power losses and the obtained temperatures, - determines if a notification indicating the level of damage or the lifetime expectation has to be performed according to the estimated thermal model and a reference thermal model. - notifies the level and location of damage or the lifetime expectation if the determining step determines that the notification has to be performed.