Power Semiconductor Module Silicone Gel Hardening Degradation

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Solution Overview

Problem

Existing power semiconductor modules inadequately suppress the influence of mutual reactions between silicone gel and component members, leading to accelerated hardening degradation and reduced insulation breakdown resistance at high temperatures, particularly in IGBT modules.

Innovation Solution

Incorporating a sheet composed of silicone rubber or silicone resin between the resin case and silicone gel within the module to prevent direct contact and reduce the generation of low molecular decomposition products, thereby suppressing hardening degradation and ensuring continuous operation at high temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If silicone gel is filled in the resin case to insulate and protect semiconductor chips, then insulation protection is improved, but hardening degradation occurs at high temperatures due to mutual reaction with resin case components

Engineering Contradiction:

Improveinsulation protectionVSAvoidsilicone gel composition stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

A sheet composed of silicone rubber or silicone resin is introduced as an intermediary barrier between the resin case and the silicone gel. This sheet prevents direct contact and mutual reaction between the resin case components and the silicone gel, thereby suppressing hardening degradation of the silicone gel while maintaining its insulation protection function.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The interior space of the resin case is segmented into two regions: a first region containing the sheet composed of silicone rubber or silicone resin, and a second region containing the silicone gel. This segmentation isolates the silicone gel from direct contact with the resin case, preventing chemical interaction and degradation.

Inventive Principle:

Principle #1Segmentation

2Power

If the module operates at high temperatures, then power conversion performance is improved, but insulation breakdown resistance decreases due to accelerated silicone gel hardening degradation

Engineering Contradiction:

Improvepower conversion performanceVSAvoidinsulation breakdown resistance

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The sheet acts as a protective intermediary that prevents the resin case components from reacting with the silicone gel even under high temperature operating conditions. This maintains the silicone gel's flexibility and insulation properties, ensuring insulation breakdown resistance is preserved during high temperature power conversion operations.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If a coating is applied to the resin case inner face to prevent reaction, then material compatibility is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvematerial compatibilityVSAvoidmanufacturing structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Instead of applying a coating to the resin case inner face, a flexible sheet composed of silicone rubber or silicone resin is placed within the resin case. This sheet is simpler to manufacture and install than a coating, while effectively preventing mutual reaction between the resin case and silicone gel through physical separation.

Inventive Principle:

Principle #30Flexible shells and thin films

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 solution effectively suppresses hardening degradation of silicone gel, maintaining insulation breakdown resistance and enabling reliable operation at high temperatures by preventing mutual reactions between the silicone gel and resin case components.

Implementation Method 1

a sheet (12) composed of silicone rubber or silicone resin is provided between the resin case (6) and the silicone gel (11) within the resin case (6)

Methodology Applied

Scientific EffectPhysical barrier prevention:

Data Source

PatentUS9123639B2Power semiconductor module

Publication Date: 2015.09.01 FUJI ELECTRIC CO LTD

AI summary

A power semiconductor module available under environments of high temperature has enhanced heat resistance of silicone gel filled up in a case. A power semiconductor module comprises a power semiconductor element, an insulating substrate mounted with the power semiconductor element, a resin case containing the power semiconductor element and the insulating substrate, a silicone gel injected into the resin case, and a sheet composed of a silicone rubber or silicone resin, disposed between the resin case and the silicone gel within the resin case.