Resin Composition for Moisture-Resistant Power Module Insulation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing heat dissipation resin sheets for power semiconductor devices lack sufficient voltage resistance and are prone to interfacial detachment due to heat expansion and contraction, which degrades the reliability of power semiconductor modules.

Innovation Solution

A resin composition comprising a resin and an aggregated inorganic filler, where the weight increase of the cured product at 85°C and 85% RH is 0.80% or less, and the storage modulus of the cured product excluding the inorganic filler at 200°C is 1.0×10^7 Pa or more, enhancing moisture-absorption reflow resistance and preventing interfacial detachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the degree of crosslinking of the epoxy resin is increased to prevent interfacial detachment, then the strength of the cured product is improved, but the moisture absorptivity increases and voltage resistance degrades under high-temperature high-humidity conditions

Engineering Contradiction:

Improvestrength of cured productVSAvoidvoltage resistance

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the epoxy resin system by using a specific epoxy resin with epoxy equivalent weight of 200-400 g/eq and combining it with a cyanate ester resin. This parameter optimization allows achieving adequate crosslinking density for strength while controlling hydroxyl group concentration to maintain low moisture absorptivity and high voltage resistance.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite resin system by combining epoxy resin with cyanate ester resin. This composite material approach allows the epoxy component to provide strength through crosslinking while the cyanate ester component suppresses moisture absorption and maintains electrical properties, thus resolving the contradiction between strength and voltage resistance.

Inventive Principle:

Principle #40Composite materials

2Temperature

If heat dissipation resin sheet is bonded to substrate to form multilayer structure, then thermal conductivity is improved, but interfacial detachment occurs due to heat expansion and contraction

Engineering Contradiction:

Improvethermal conductivityVSAvoidinterfacial detachment

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent optimizes the coefficient of thermal expansion parameter of the resin composition by selecting specific resin types and ratios, as well as controlling filler content. This allows the cured product to have thermal expansion characteristics that match the metal substrate, reducing thermal stress and preventing interfacial detachment while maintaining high thermal conductivity.

Inventive Principle:

Principle #35Parameter changes

3Strength

If ceramic substrate is used as heat dissipation substrate, then thermal conductivity and integration strength are improved, but crack resistance is reduced and size reduction becomes difficult

Engineering Contradiction:

Improveintegration strengthVSAvoidcrack resistance

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the traditional ceramic substrate with a resin-based composite material that, while having different mechanical properties, provides sufficient performance for the application. The resin composition is designed to achieve adequate strength, thermal conductivity, and crack resistance, offering a more flexible and size-reducible alternative to ceramic substrates.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent uses a composite resin system combining epoxy resin, cyanate ester resin, and inorganic filler to create a material that mimics and surpasses ceramic substrate performance in certain aspects. The composite structure provides both the thermal management capabilities and the mechanical flexibility needed to avoid ceramic cracking while maintaining integration strength.

Inventive Principle:

Principle #40Composite materials

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 resin composition achieves high strength and excellent moisture-absorption reflow resistance, minimizing the risk of interfacial detachment due to heat expansion and contraction, thereby improving the reliability of power semiconductor modules.

Implementation Method 1

an increase in a weight of a cured product of the resin composition at 85° C. and 85% RH is 0.80% or less

Methodology Applied

Scientific EffectMoisture absorption: Absorption (physical)

Implementation Method 2

interfacial detachment is likely to occur due to heat expansion and contraction caused by a large amount of heat produced during use

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS12264229B2Resin composition, resin cured product, and composite molded body

Publication Date: 2025.04.01 MITSUBISHI CHEM CORP

AI summary

A resin composition comprising a resin and an aggregated inorganic filler, wherein an increase in a weight of a cured product of the resin composition at 85° C. and 85% RH is 0.80% or less, and wherein a storage modulus of a cured product of the resin composition excluding the inorganic filler at 200° C. is 1.0×107 Pa or more. The resin composition has a high strength and excellent moisture-absorption reflow resistance and reduces the risk of the interfacial detachment being caused by the heat expansion and contraction in the case where the resin composition or the resin cured product is combined with a metal sheet to form a multilayer body.