Power Module Frame Body and Heat Radiation Member Design

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Solution Overview

Problem

The existing power module structure, which uses adhesive to attach the bottom case, top case, and side case, lacks rigidity and durability, leading to concerns about deformation and mechanical stability when fixed to the housing of the power conversion apparatus.

Innovation Solution

A power module design featuring a metallic frame body with a heat radiation member and a heat radiation fin unit, where the heat radiation member has a higher conductivity than the frame body, and the frame body is more rigid, with a joint portion at the external peripheral edge, and the heat sinks are arranged to face each other with a fin peripheral edge unit to enhance heat radiation and mechanical stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If adhesive is used to attach the bottom case, top case, and side case, then the assembly process is simplified, but the rigidity and durability of the power module deteriorate

Engineering Contradiction:
Improveassembly processVSAvoidrigidity and durability
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The power module structure is segmented into distinct functional components: a frame body for mechanical support and rigidity, heat sinks for thermal management, and a case for protection. This segmentation allows each component to be optimized for its specific function while being joined through robust mechanical connections rather than adhesive bonding alone.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The power module employs composite construction combining different materials with complementary properties: aluminum or aluminum alloy for the frame body and heat sinks to provide both structural integrity and thermal conductivity, and adhesive materials selected for their high strength and temperature resistance to supplement the mechanical joints.

Inventive Principle:
Principle #40Composite materials

2Temperature

If a metallic frame body with heat radiation member is used, then the heat radiation performance is improved, but the device complexity increases

Engineering Contradiction:
Improveheat radiation performanceVSAvoidstructure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The frame body serves multiple functions simultaneously: it provides the structural framework for the power module, acts as a heat conduction path from the semiconductor devices, and supports the heat sinks. The heat sinks similarly serve both thermal management and structural support functions, reducing the need for separate components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The frame body and heat sinks are integrated into a unified thermal management system where the frame body serves as both structural support and heat conduction element. The heat sinks are directly coupled to the frame body, merging the mechanical support function with the thermal management function into a single integrated structure.

Inventive Principle:
Principle #5Merging (Combining)

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 achieves high rigidity and heat radiation performance, improving the durability and mechanical stability of the power module and power conversion apparatus, while efficiently transferring heat to the coolant in the cooling channel.

Implementation Method 1

the heat radiation member has a heat conductivity higher than that of the frame body

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

heat radiation fin unit having a plurality of heat radiation fins vertically arranged thereon

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 3

cooling the power module by way of radiation fins provided at both sides

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2720368B1Power module and power conversion apparatus using same
Publication Date: 2017.02.08 HITACHI AUTOMOTIVE SYST LTD
  • EP2720368B1 patent drawingFigure 1
  • EP2720368B1 patent drawingFigure 2
  • EP2720368B1 patent drawingFigure 3

AI summary

A power module includes a plurality of semiconductor devices constituting upper/lower arms of an inverter circuit, a plurality of conductive plates arranged to face electrode surfaces of the semiconductor devices and a module case configured to accommodate the semiconductor devices and the conductive plates, wherein the module case includes a heat radiation member made of plate-like metal and facing a surface of the conductive plate and a metallic frame body having an opening portion that is closed by the heat radiation member, and wherein a heat radiation fin unit having a plurality of heat radiation fins vertically arranged thereon is provided at a center of the heat radiation member, and a joint portion with the frame body is provided at an external peripheral edge of the heat radiation member, and the heat radiation member has a heat conductivity higher than that of the frame body, and the frame body is of a higher rigidity than that of the heat radiation member.