Semiconductor Device Thermal Expansion Management

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Solution Overview

Problem

Conventional semiconductor devices experience deformation due to temperature rise, leading to the pumping out of heat dissipating materials, which do not return to their original state, resulting in reduced heat dissipation efficiency.

Innovation Solution

A semiconductor device design where the insulating substrate and base plate are not fixed to each other, allowing for thermal expansion without protrusion, and using a heat dissipating material interposed between them to prevent material displacement and maintain contact with the radiator.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the insulating substrate and base plate are fixed together, then structural stability is improved, but thermal expansion causes deformation and pumping out of heat dissipating material

Engineering Contradiction:

Improvestructural stabilityVSAvoidheat dissipation reliability

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent divides the thermal management structure into separate components (insulating substrate and base plate) that are not rigidly fixed together. This segmentation allows each component to independently accommodate thermal expansion while maintaining overall structural integrity and heat dissipation functionality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent modifies the structural parameters by removing rigid fixation between the insulating substrate and base plate, allowing dynamic adjustment during thermal cycles. This parameter change enables the structure to accommodate thermal expansion without deformation or material pumping out.

Inventive Principle:

Principle #35Parameter changes

2Strength

If the base plate is rigidly connected to the insulating substrate, then mechanical strength is improved, but thermal expansion during temperature rise causes deformation and material displacement

Engineering Contradiction:

Improvemechanical strengthVSAvoiddeformation

Core Design Contradiction:

StrengthVSShape

Solution Approach 1:

The patent introduces dynamic characteristics to the connection between the base plate and insulating substrate, allowing relative movement during thermal expansion. This dynamic approach maintains mechanical strength while preventing deformation and material displacement that would occur with rigid fixation.

Inventive Principle:

Principle #15Dynamics

3Loss of energy

If heat dissipating material is used to fill gaps, then heat dissipation is improved, but thermal expansion pushes the material out and creates permanent gaps

Engineering Contradiction:

Improveheat dissipation efficiencyVSAvoidmaterial position stability

Core Design Contradiction:

Loss of energyVSStability of the object's composition

Solution Approach 1:

The patent applies beforehand cushioning by designing a structure that anticipates thermal expansion effects. The non-fixed connection between components prevents the pumping out action that would displace heat dissipating material, thereby maintaining material position stability and continuous heat dissipation efficiency throughout thermal cycles.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 effectively suppresses the pumping out of heat dissipating materials, thereby maintaining heat dissipation efficiency even during temperature changes, especially when using wide band gap semiconductors.

Implementation Method 1

a lower surface of the insulating substrate and an upper surface of the base plate are in contact with each other with interposition of the heat dissipating material

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the insulating substrate and the base plate are not fixed to each other... capable of suppressing pumping out of a heat dissipating material, thereby suppressing decrease in heat dissipation

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS20230215776A1Semiconductor device

Publication Date: 2023.07.06 MITSUBISHI ELECTRIC CORP

AI summary

A semiconductor device includes: an insulating substrate; a semiconductor chip; a base plate; a first heat dissipating material; and a case. The semiconductor chip and a sealing material for sealing the semiconductor chip are housed in the case. The insulating substrate includes an insulating layer and a conductor pattern provided on an upper surface of the insulating layer. The semiconductor chip is joined onto the conductor pattern by a joining material. A lower surface of the insulating substrate and an upper surface of the base plate are in contact with each other with interposition of the first heat dissipating material. The insulating substrate and the base plate are not fixed to each other.