Insulating Resin Composition for Circuit Substrates

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Metal base circuit substrates have poorer heat dissipation properties compared to ceramic circuit substrates, and they require high reliability under conditions of high temperature, high humidity, and high-voltage application.

Innovation Solution

An insulating resin composition comprising an epoxy resin, an amine-based curing agent with specific amine compounds, and an inorganic filler with high thermal conductivity, which forms an insulating layer with excellent insulation reliability, heat cycle resistance, and thermal conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If ceramic circuit substrates are used to achieve high heat dissipation properties, then thermal conductivity is improved, but manufacturing cost increases significantly

Engineering Contradiction:
Improveheat dissipation propertiesVSAvoidmanufacturing cost
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The invention uses a composite resin composition containing epoxy resin, specific amine-based curing agents, and inorganic fillers (such as aluminum oxide, aluminum nitride, or boron nitride) to create a material that combines the low cost and ease of processing of resin-based materials with the high thermal conductivity previously only achievable with ceramic substrates

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention optimizes the molecular structure of the amine-based curing agent (using compounds with specific formulas and ratios of primary, secondary, and tertiary amine groups) and adjusts the composition ratios of resin components and inorganic fillers to achieve maximum thermal conductivity while maintaining cost-effectiveness and processing ease

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If metal base circuit substrates are used to reduce cost compared to ceramic substrates, then manufacturing cost is improved, but heat dissipation properties deteriorate

Engineering Contradiction:
Improvemanufacturing costVSAvoidheat dissipation properties
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The invention creates a composite material system that combines organic resin components (epoxy resin and amine-based curing agent) with inorganic thermal conductive fillers, achieving a balance between cost-effectiveness and high thermal conductivity (thermal conductivity of 1.0 W/mK or more)

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention enhances the thermal conductivity of specific regions within the insulating resin layer by incorporating inorganic fillers with high thermal conductivity, creating localized heat dissipation pathways without requiring the entire substrate to be made of expensive ceramic materials

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If conventional epoxy resin compositions are used to simplify manufacturing, then ease of manufacture is improved, but insulation reliability under high temperature and high humidity conditions deteriorates

Engineering Contradiction:
Improveease of manufactureVSAvoidinsulation reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention modifies the chemical parameters of the curing agent by selecting amine-based compounds with specific molecular structures (formulas (A-1) and (A-2) with controlled ratios of primary, secondary, and tertiary amine groups), which enhances the cross-linking structure of the cured resin and improves insulation reliability under harsh environmental conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention combines epoxy resin with specifically formulated amine-based curing agents and inorganic fillers to create a composite system that maintains ease of manufacturing through standard processing methods while achieving superior insulation reliability and heat cycle resistance

Inventive Principle:
Principle #40Composite materials

4Device complexity

If conventional curing agents are used to simplify the composition, then device complexity is reduced, but heat cycle resistance deteriorates

Engineering Contradiction:
Improvecomposition complexityVSAvoidheat cycle resistance
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The invention optimizes the molecular parameters of the amine-based curing agent, specifically controlling the ratio of primary, secondary, and tertiary amine groups and the carbon atom counts in R1 and R2 groups, to achieve enhanced heat cycle resistance while maintaining a relatively simple two-component curing system

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces specific functional groups and molecular structures at critical locations within the curing agent molecules to enhance the overall heat cycle resistance of the cured resin system without significantly increasing the overall complexity of the composition

Inventive Principle:
Principle #3Local quality

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 insulating resin composition achieves excellent insulation reliability, high heat cycle resistance, and high thermal conductivity, making it suitable for circuit substrates under conditions of high temperature, high humidity, and high-voltage application.

Implementation Method 1

an inorganic filler having a thermal conductivity of 20 W/mK or higher

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

an amine-based curing agent containing a first amine compound represented by Formula (A-1) and a second amine compound represented by Formula (A-2)

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Data Source

PatentEP4129676B1Insulating resin composition, insulating resin cured body, layered body, and circuit substrate
Publication Date: 2025.02.12 DENKA CO LTD
  • EP4129676B1 patent drawingFigure 1
  • EP4129676B1 patent drawingFigure 2
  • EP4129676B1 patent drawing

AI summary

Provided is an insulating resin composition including: an epoxy resin; an amine-based curing agent containing a first amine compound represented by Formula (A-1) and a second amine compound represented by Formula (A-2); and an inorganic filler having a thermal conductivity of 20 W/mK or higher, in which a content of the inorganic filler is 30 to 80 volume%. [In the formula, Y represents -NH2 or -NHR1 (R1 represents a group represented by Formula (Y-1)), and at least one of Y's is -NHR1]. [In Formula (Y-1), R2 represents an alkyl group].