Integrated Power Semiconductor Temperature Sensing in Bridge Circuits

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Solution Overview

Problem

Existing power semiconductor circuits require additional space and connections for temperature and current measurement, leading to inefficiencies and potential damage from high temperatures and currents, as they often rely on separate temperature sensors and measuring resistors that are not directly integrated within the semiconductor component.

Innovation Solution

A power semiconductor circuit design that integrates a temperature sensor, such as a temperature diode, directly within the power semiconductor element, allowing for temperature measurement using a single connection and internal resistors for current measurement, thereby reducing space requirements and connection complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a separate temperature sensor is applied to the housing or heat sink of the semiconductor component, then the temperature can be measured, but the temperature measured is not the actual temperature inside the semiconductor component where the temperature is highest

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidsensor arrangement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The temperature sensor is integrated directly into the semiconductor component structure, nested within the same module housing. This allows the sensor to be positioned at the actual location of highest temperature (inside the component) rather than on external surfaces, achieving accurate temperature measurement while maintaining a compact integrated design

Inventive Principle:
Principle #7Nested doll (Nesting)

2Measurement precision

If a temperature sensor is arranged within a module next to the chip of an IGBT, then temperature measurement is possible, but the space requirement increases and the area available for the actual semiconductor component is reduced

Engineering Contradiction:
Improvetemperature measurement capabilityVSAvoidmodule area
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The temperature sensor and the semiconductor component are merged into a single integrated module structure. The sensor shares the same housing and space as the power semiconductor element, eliminating the need for separate dedicated sensor space. This combining approach enables temperature measurement without increasing the overall module footprint

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If TCS-IGBTs place some IGBT cells on a separate connection for current measurement, then current can be measured, but those cells are not available for the actual task of the IGBT and additional space is required

Engineering Contradiction:
Improvecurrent measurement capabilityVSAvoidIGBT operational capacity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

A separate current sensing element (such as a Hall effect sensor or shunt resistor) is introduced as an intermediary component to measure current without requiring any IGBT cells to be diverted for measurement purposes. This intermediary sensor measures the current flowing through the IGBT externally, allowing all IGBT cells to remain dedicated to their primary switching function while still enabling accurate current monitoring

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This design enables precise temperature and current measurement with reduced space and connection needs, enhancing the protection of power semiconductor components from high temperatures and currents while maintaining operational efficiency.

Implementation Method 1

a voltage drop across the temperature sensor can be measured between the measuring connection and the first emitter connection for temperature measurement

Methodology Applied
Scientific EffectTemperature-dependent voltage measurement: Seebeck Effect

Data Source

PatentEP3608644B1Method of determining a sign of a load current in a bridge circuit with at least one power semiconductor circuit
Publication Date: 2021.03.24 INFINEON TECHNOLOGIES AG
  • EP3608644B1 patent drawingFigure 1
  • EP3608644B1 patent drawingFigure 2
  • EP3608644B1 patent drawingFigure 3

AI summary

The invention relates to a power semiconductor circuit (1) for determining the temperature of a power semiconductor element (20), comprising the power semiconductor element (20) and a temperature sensor (10), wherein the power semiconductor element (20) has a gate electrode (G) for controlling the power semiconductor element (20), a collector electrode (C) and an emitter electrode (E), wherein the emitter electrode (E) is electrically connected to a first emitter terminal (HE) and the temperature sensor (10) has a first measuring point (11) with a measuring terminal (TC) and a second measuring point (12), wherein the second measuring point (12) is electrically connected to the emitter electrode (E), so that a voltage drop across the temperature sensor (10) between measuring terminal (TC) and first emitter terminal (HE) can be measured for temperature measurement.The invention further relates to a method for determining the temperature of a power semiconductor element (20) by means of such a power semiconductor circuit (1) and furthermore to a bridge circuit with at least one such power semiconductor circuit (1).