Power Semiconductor Module Compressive Stress Cooling

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Solution Overview

Problem

Conventional power semiconductor modules face challenges in reducing size while maintaining effective heat release performance, leading to increased costs and potential damage due to tensile stress and detachment of insulating members, which degrades heat releasing properties.

Innovation Solution

A power semiconductor module design featuring a circuit unit housed between first and second heat releasing plates with intermediate connecting portions that generate compressive stress, reducing springback and improving thermal conductivity, and using a can-type cooler with insulating members to enhance heat transfer and prevent detachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If holding plate and plate spring member are used to sandwich stack unit, then cooling tubes are brought into contact with semiconductor modules, but the stack unit becomes large in size and costs increase

Engineering Contradiction:

Improvecontact between cooling tubes and semiconductor modulesVSAvoidsize of stack unit

Core Design Contradiction:

ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent merges the holding plate and plate spring member into a single integrated case structure. The case directly contacts the semiconductor modules and cooling tubes without requiring separate holding components, thereby reducing the overall size while maintaining reliable thermal contact.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The case serves multiple functions: it houses the semiconductor modules, provides thermal contact with cooling tubes, and replaces the need for separate holding plate and spring member. This multi-functionality reduces component count and overall assembly size.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If semiconductor circuit unit is bonded to inner wall via insulating member, then electrical insulation is secured, but tensile stress is generated and insulating member might detach

Engineering Contradiction:

Improveelectrical insulationVSAvoidbonding strength of insulating member

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent converts the harmful tensile stress into beneficial compressive stress by designing the case to generate compression on the semiconductor circuit unit. This compressive stress prevents detachment of the insulating member while maintaining electrical insulation, effectively turning a potential failure mode into a strengthening mechanism.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the stress state from tensile to compressive by modifying the case structure. The case is designed to apply compressive force on the semiconductor circuit unit, which fundamentally alters the stress parameters and prevents insulating member detachment.

Inventive Principle:

Principle #35Parameter changes

3Volume of stationary object

If heat releasing plates are made thinner to reduce size, then module size decreases, but springback increases and heat releasing properties degrade

Engineering Contradiction:

Improvesize of heat releasing platesVSAvoidheat releasing properties

Core Design Contradiction:

Volume of stationary objectVSReliability

Solution Approach 1:

The patent changes the stress parameter from tensile to compressive, which fundamentally alters the springback behavior. Compressive stress reduces springback in thin plates, allowing the heat releasing plates to be made thinner without degrading their heat releasing properties.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the potential harm of thin plate springback into a benefit by applying compressive stress. The compression prevents the plates from springing back and losing contact, thereby maintaining effective heat release while enabling thinner plate design.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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

The design enhances cooling performance, reduces module size, and increases reliability by minimizing springback and maintaining effective heat release, thus improving the overall efficiency and durability of the power semiconductor module.

Implementation Method 1

The first intermediate connecting portion is designed so that the first heat releasing plate generates first compressive stress in the direction toward the location of the circuit unit, and the second intermediate connecting portion is designed so that the second heat releasing plate generates second compressive stress in the direction toward the location of the circuit unit.

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS9474191B2Power semiconductor module

Publication Date: 2016.10.18 ASTEMO LTD

AI summary

Each of a plurality of power semiconductor module includes a can-type cooling case that is formed with a plate spring portion that generates compressive stress in the semiconductor circuit unit, an adjustment portion that is deformed to adjust elastic deformation of the plate spring portion, and a sidewall portion to which the plate spring portion and the adjustment portion are joined.