Power Semiconductor Module Stress-Reducing Adjustment Element

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Solution Overview

Problem

Power semiconductor modules experience detachment of conductor tracks from insulating bodies due to differential thermal expansion coefficients between connection elements and substrates, leading to instability during continuous operation and production processes.

Innovation Solution

The power semiconductor module incorporates a substrate with a first and second metallic layer forming conductor tracks, where a first matching element is materially bonded to the connection element and a second matching element is connected to the substrate or cooling device using a connecting means, distributing thermal loads across two connections to prevent detachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If connection elements with high electrical conductivity are used, then electrical performance is improved, but thermal expansion mismatch causes conductor track detachment

Engineering Contradiction:
Improveelectrical connection stabilityVSAvoidconductor track attachment
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent introduces matching elements as intermediary components between the connection element and the conductor track. These matching elements have thermal expansion coefficients that are intermediate between those of the connection element and the substrate, thereby reducing the differential thermal expansion stress and preventing conductor track detachment while maintaining electrical connectivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the thermal expansion parameter by selecting materials for the matching elements with specific thermal expansion coefficients that differ from both the connection element and the substrate. This parameter optimization reduces the thermal stress differential and prevents detachment during thermal cycling.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If single connection between connection element and conductor track is used, then device complexity is reduced, but thermal load concentration causes detachment during continuous operation

Engineering Contradiction:
Improveconnection structureVSAvoidcontinuous operation stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the thermal load path by introducing matching elements that create additional connection interfaces. Instead of a single direct connection between the connection element and conductor track, the path is divided into multiple segments (connection element to matching element, matching element to conductor track), distributing the thermal stress across multiple points.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent adds a dimensional aspect to the connection structure by inserting matching elements that extend the connection path in the vertical dimension. This creates a multi-layered connection architecture that distributes thermal loads across different spatial levels rather than concentrating them at a single interface.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 configuration effectively prevents conductor track detachment from the insulating body by distributing thermal loads across two connections, enhancing the resilience and stability of the module during continuous operation and production.

Implementation Method 1

detachment of the conductor track from the insulating body due to differential thermal expansion coefficients between connection elements and substrates

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

distributing thermal loads across two connections to prevent detachment

Methodology Applied
Scientific EffectStress distribution:

Data Source

PatentEP2685492B1Power semiconductor module with at least one stress-reducing adjustment element
Publication Date: 2018.07.11 SEMIKRON DANFOSS ELEKTRONIK GMBH & CO KG
  • EP2685492B1 patent drawingFigure 1
  • EP2685492B1 patent drawingFigure 2~3
  • EP2685492B1 patent drawingFigure 4

AI summary

The module has a substrate (2) arranged on a cooling device or a base plate. A power semiconductor component (30) is electrical conductively connected with strip conductors (220, 222). An adjustment element (50) and a connector (60) are arranged on the strip conductors. A major surface of the adjustment element is fixed adjacent to the connector such that two connection types are formed while another major surface of the adjustment element is electrical conductively and firmly bonded by a connection unit (70), where the latter major surface is fixed adjacent to one of strip conductors. The connector is designed as load and auxiliary connectors.