Power Semiconductor Module Layout for Heat Dissipation and Isolation

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Solution Overview

Problem

Conventional power semiconductor modules suffer from poor heat dissipation properties due to the low thermal conductivity of resin packages, leading to excessive temperature increases and potential module failure. Additionally, exposing multiple conductive heat dissipation substrates increases the risk of short circuit failures from conductive foreign objects.

Innovation Solution

The solution involves an attachment structure where at least one metal substrate with a power semiconductor device is exposed for heat dissipation, while the majority of other metal substrates are embedded in the resin package. This configuration enhances heat dissipation without increasing the heat dissipation area, thereby reducing the module's size and minimizing the risk of short circuit failures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If all metal substrates are exposed to the heat dissipation surface, then heat dissipation properties improve, but the risk of short circuit failure increases due to conductive foreign objects

Engineering Contradiction:
Improveheat dissipation propertiesVSAvoidshort circuit failure risk
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent applies local quality by differentiating the treatment of metal substrates based on their specific functions. Power semiconductor device mounting substrates are exposed to the heat dissipation surface to enable efficient heat removal, while other metal substrates (such as internal wiring substrates) are embedded in the resin package to prevent short circuit risks. This selective exposure strategy optimizes both heat dissipation performance and electrical safety.

Inventive Principle:
Principle #3Local quality

2Temperature

If the resin package is made thin to improve heat dissipation, then heat dissipation properties improve, but the mechanical strength and protection of internal components deteriorate

Engineering Contradiction:
Improveheat dissipation propertiesVSAvoidmechanical strength and protection
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The patent implements local quality by creating a non-uniform resin package structure where the resin thickness varies in different regions. In areas where metal substrates are embedded, the resin provides adequate thickness for mechanical strength and electrical insulation. In areas where heat dissipation is critical, the resin package is made thinner to reduce thermal resistance. This spatially differentiated design allows simultaneous optimization of both mechanical protection and heat dissipation performance.

Inventive Principle:
Principle #3Local quality

3Temperature

If multiple metal substrates are exposed to increase heat dissipation area, then heat dissipation properties improve, but the module size increases

Engineering Contradiction:
Improveheat dissipation propertiesVSAvoidmodule size
Core Design Contradiction:
TemperatureVSArea of stationary object

Solution Approach 1:

The patent applies the extraction principle by removing only the necessary metal substrates (those requiring heat dissipation) from the resin package, while leaving other metal substrates embedded. This selective extraction approach ensures that heat dissipation area is sufficient for thermal management, while avoiding the increased module size that would result from exposing all metal substrates. The embedded substrates maintain their functional roles without contributing to external heat dissipation surface area.

Inventive Principle:
Principle #2Taking out (Extraction)

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 approach achieves high heat dissipation properties in a compact size, reducing the risk of short circuit failures by embedding metal substrates with low heat dissipation needs within the resin package, thus preventing conductive foreign objects from causing short circuits.

Implementation Method 1

the heat emitted from the semiconductor devices passes through the heat dissipation substrate... heat dissipation properties

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

embedded in the insulating resin package... risk that causes short circuit failure can be reduced

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Data Source

PatentEP2500939B2Power semiconductor module attachment structure
Publication Date: 2025.05.07 MITSUBISHI ELECTRIC CORP
  • EP2500939B2 patent drawingFigure 1
  • EP2500939B2 patent drawingFigure 2~3
  • EP2500939B2 patent drawingFigure 4~5

AI summary

A power semiconductor module includes: a first metal substrate on which a power semiconductor device is mounted; a second metal substrate on which a power semiconductor device is not mounted; and an electrically insulating resin package which seals the first metal substrate and the second metal substrate. The back surface of the first metal substrate on the side opposite to the mounting surface of the power semiconductor device is made to expose outside the resin package to form a heat dissipation surface.