Power Module Case With Elastic Intermediate Member

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Solution Overview

Problem

The existing power modules for hybrid and electric automobiles face challenges in improving productivity, terminal connection reliability, reducing size, and enhancing heat radiation properties for semiconductor devices housed in cases.

Innovation Solution

A power module configuration that includes a sealing body with a semiconductor element, conductor plates, and a case with heat radiation plates connected by an intermediate member that can be elastically deformed, allowing for improved heat dissipation and secure fixation, along with a manufacturing method that involves elastic deformation and pressurization to ensure precise fitting and sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a resin-molded semiconductor device is housed in a case, then productivity and reliability of terminal connection should be improved, but the housing process is complex and time-consuming

Engineering Contradiction:
Improvereliability of terminal connectionVSAvoidproductivity in housing
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The case is designed with an elastic deformable portion that can dynamically change shape during the housing process. The case is pressed to deform the elastic portion, allowing the semiconductor device to be inserted, and then the elastic force automatically restores the case to its original shape, securing the device in place. This dynamic mechanism eliminates complex fastening steps while ensuring reliable terminal connections.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The elastic deformable portion of the case provides self-service functionality by automatically securing the semiconductor device through elastic restoration. After the device is inserted by pressing the case, the elastic force automatically returns the case to its original shape, creating a self-locking mechanism that secures the device without additional fastening operations, thereby improving productivity.

Inventive Principle:
Principle #25Self-service

2Temperature

If heat radiation plates are added to both sides of the semiconductor device, then heat radiation properties are improved, but the device size increases

Engineering Contradiction:
Improveheat radiation propertiesVSAvoiddevice size
Core Design Contradiction:
TemperatureVSVolume of moving object

Solution Approach 1:

The case is designed to serve multiple functions: it provides mechanical protection for the semiconductor device, secures the device through elastic deformation, and acts as a heat radiation plate on both sides. By integrating the heat radiation function into the case structure itself, additional heat radiation plates are eliminated, preventing increase in device size while maintaining excellent heat radiation properties.

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

3Reliability

If the case structure is made rigid for secure fixation, then reliability of housing is improved, but ease of insertion and productivity are reduced

Engineering Contradiction:
Improvereliability of housingVSAvoidease of insertion
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The case incorporates an elastic deformable portion that transitions between flexible and rigid states. During insertion, the case is pressed to deform the elastic portion, making it flexible and easy to insert the semiconductor device. After insertion, the elastic force restores the case to its rigid original shape, providing secure fixation. This dynamic state change resolves the contradiction between rigidity for reliability and flexibility for ease of insertion.

Inventive Principle:
Principle #15Dynamics

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 configuration enhances productivity, reliability of terminal connections, and heat radiation properties, leading to a more efficient and compact power module design for automotive applications.

Implementation Method 1

the sealing body is pressed against and fixed to the second heat radiation plate via the first heat radiation plate by elastic force generated in the first thin section

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP2565918B1Power module and method for manufacturing power module
Publication Date: 2018.12.05 HITACHI AUTOMOTIVE SYST LTD
  • EP2565918B1 patent drawingFigure 1
  • EP2565918B1 patent drawingFigure 2
  • EP2565918B1 patent drawingFigure 3

AI summary

A power module includes: a sealing body including a semiconductor element having a plurality of electrode surfaces, a first conductor plate connected to one electrode surface of the semiconductor element via solder, and a sealing material for sealing the semiconductor element and the first conductor plate, the sealing body having at least a first surface and a second surface on the opposite side of the first surface; and a case for housing the sealing body. The case is configured by a first heat radiation plate opposed to the first surface of the sealing body, a second heat radiation plate opposed to the second surface of the sealing body, and an intermediate member that connects the first heat radiation plate and the second heat radiation plate. The intermediate member has a first thin section having thickness smaller than the thickness of the first heat radiation plate, more easily elastically deformed than the first heat radiation plate, and formed to surround the first heat radiation plate. The sealing body is pressed against and fixed to the second heat radiation plate via the first heat radiation plate by elastic force generated in the first thin section.