Power Converter Circuit Body With Deformable Heat Conduction Layer

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Solution Overview

Problem

Existing power modules using ceramic substrates are expensive and hinder effective heat dissipation, necessitating a more efficient and cost-effective solution.

Innovation Solution

An electric circuit body design that sandwiches power semiconductor elements between conductor plates, uses a sheet-shaped member with a resin insulating layer and metal-based heat conduction member to improve heat dissipation without relying on ceramic substrates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a ceramic substrate is used for heat dissipation in power modules, then heat dissipation performance is improved, but manufacturing cost increases significantly

Engineering Contradiction:

Improveheat dissipation performanceVSAvoidmanufacturing cost

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The patent replaces expensive ceramic substrates with a cost-effective combination of resin insulating layers and metal heat conduction members. The resin sheet (epoxy or polyimide) combined with aluminum or copper heat conduction members provides adequate heat dissipation performance at lower manufacturing cost compared to ceramic substrates, while maintaining the necessary thermal and electrical insulation properties

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent employs a composite structure consisting of a resin insulating layer (epoxy resin or polyimide) combined with a metal heat conduction member (aluminum or copper). This composite material approach achieves both electrical insulation and thermal conduction functions, replacing the traditional ceramic substrate while balancing cost, insulation performance, and heat dissipation requirements

Inventive Principle:

Principle #40Composite materials

2Stability of the object's composition

If conductor plates are rigidly fixed to power semiconductor elements, then structural stability is improved, but heat dissipation efficiency decreases due to warpage

Engineering Contradiction:

Improvestructural stabilityVSAvoidheat dissipation efficiency

Core Design Contradiction:

Stability of the object's compositionVSTemperature

Solution Approach 1:

The patent uses a flexible resin sheet (epoxy resin sheet or polyimide sheet) as an intermediate layer between the conductor plates and power semiconductor elements. This flexible film can deform to accommodate warpage in the conductor plates, maintaining intimate thermal contact with the semiconductor elements while providing electrical insulation, thus preserving heat dissipation efficiency despite structural deformations

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent changes the material parameters by selecting resin materials (epoxy or polyimide) with specific thermal and mechanical properties that allow the insulating layer to accommodate warpage deformation. The metal heat conduction members are also selected with appropriate thermal conductivity parameters to ensure efficient heat transfer even when contact pressure varies due to warpage

Inventive Principle:

Principle #35Parameter changes

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

Enhances heat dissipation by plastically deforming the metal-based heat conduction member to match conductor plate warpage, reducing thermal resistance and eliminating the need for ceramic substrates.

Implementation Method 1

a metal-based heat conduction member provided between the sheet-shaped member and the cooling member so as to be in contact with the sheet-shaped member and the cooling member

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a sheet-shaped member adhered to at least the second conductor plate and having at least a resin insulating layer

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

a high efficiency device using a water cooling system is adopted for reduction in size and weight

Methodology Applied

Scientific EffectForced convection: Forced Convection

Data Source

PatentUS12506046B2Electric circuit body, power converter, and method for manufacturing electric circuit body

Publication Date: 2025.12.23 ASTEMO LTD

AI summary

A sheet-shaped member 440 including a resin insulating layer 441 and a metal foil 442 is used. The sheet-shaped member 440 is deformed following warpage or step difference in a second conductor plate 431 and a fourth conductor plate 433, and therefore, the thickness of the resin insulating layer 441 can be set to a constant thickness of, for example, 120 μm capable of securing insulation properties. By plastically deforming a metal-based heat conduction member 450 having a thickness of, for example, 120 μm interposed between the sheet-shaped member 440 and a cooling member 340, the thickness of the metal-based heat conduction member 450 is changed to absorb the warpage or step difference generated in the second conductor plate 431 and the fourth conductor plate 433. This results in remarkable improvement in heat dissipation as compared with a case where the conductor plates are brought into contact with the cooling member 340 via an insulating layer alone.