Silicone Resin Electronic Component Flame Retardancy

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Electronic components, such as varistors, require higher overvoltage protection while maintaining incombustibility and insulation withstand voltage characteristics, but existing silicone-based resin materials are expensive and difficult to form effectively with high concentrations of flame-retardant agents.

Innovation Solution

A production method for electronic components that includes an exterior packaging material with a high concentration of aluminum hydroxide or magnesium hydroxide, ranging from 60 to 65 wt.%, and a nonpolar solvent with a vapor pressure of 0.5 to 10 kPa, ensuring uniform dispersion and improved formability while reducing the amount of silicone resin used.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a high concentration of flame-retardant agent (bromine or antimony) is added to epoxy resin to make the exterior packaging material incombustible, then flame retardancy is improved, but the resin fluidity decreases making it difficult to form an exterior packaging film

Engineering Contradiction:
Improveflame retardancyVSAvoidformability of exterior packaging film
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the chemical composition parameters of the resin system by introducing a specific silane-modified epoxy resin with particular functional groups and molecular structure. This parameter change allows the resin to maintain fluidity while incorporating flame-retardant agents, as the modified resin structure provides different flow characteristics compared to conventional epoxy resins.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system combining silane-modified epoxy resin with specific flame-retardant agents and fillers. This composite approach allows the flame-retardant properties to be achieved through the synergistic effect of multiple components rather than relying solely on high concentrations of bromine or antimony, thereby maintaining resin processability.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the amount of combustible component in exterior packaging material is reduced to combustion limit amount or less to make it incombustible, then flame retardancy is improved, but the mechanical strength and heat resistance of the varistor decrease

Engineering Contradiction:
Improveflame retardancyVSAvoidmechanical strength and heat resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent modifies the chemical parameters of the resin base by using silane-modified epoxy resin, which alters the curing characteristics and network structure. This enables the formation of a resilient crosslinked structure that maintains mechanical strength even when combustible component content is reduced to meet flame retardancy requirements.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite material strategy where silane-modified epoxy resin is combined with specific inorganic fillers and flame-retardant additives. This composite structure provides both flame retardancy through the reduced combustible content and maintains mechanical strength through the reinforced network formed by the silane modification and filler integration.

Inventive Principle:
Principle #40Composite materials

3Reliability

If bromine-based flame-retardant agent is used to suppress combustion of resin component through gasification, then flame retardancy is improved, but environmental burden increases due to ozone layer depletion

Engineering Contradiction:
Improveflame retardancyVSAvoidenvironmental burden
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces persistent environmental contaminants (bromine-based flame-retardant agents that deplete ozone) with alternative flame-retardant mechanisms based on silane-modified epoxy resin. This substitution eliminates the use of harmful substances while maintaining flame retardancy functionality through the modified resin's inherent fire-resistant properties and controlled combustion behavior.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent converts the potential harm of epoxy resin combustion into a beneficial flame-retardant mechanism by using silane modification. The silane groups undergo controlled decomposition and charring when exposed to fire, forming a protective carbonaceous layer that prevents further combustion, thereby transforming the resin's combustibility from a harmful property into a controlled, self-protective flame-retardant mechanism.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 method allows for reduced silicone resin usage while maintaining incombustibility and insulation withstand voltage characteristics, preventing resin scattering during overvoltage events and lowering manufacturing costs.

Implementation Method 1

a flame-retardant material used is, for example, an epoxy resin containing bromine or antimony, which is a flame-retardant agent. However, although being flame-retardant, the epoxy resin may combust if the varistor generates heat in a continuous manner.

Methodology Applied
Scientific EffectHeat absorption during decomposition: Endothermic Reaction

Implementation Method 2

A production method for electronic components that includes an exterior packaging material with a high concentration of aluminum hydroxide or magnesium hydroxide, ranging from 60 to 65 wt.%, and a nonpolar solvent with a vapor pressure of 0.5 to 10 kPa, ensuring uniform dispersion and improved formability

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Data Source

PatentEP3070720B1Electronic component and production method therefor
Publication Date: 2019.06.12 NIPPON CHEMI CON CORP
  • EP3070720B1 patent drawingFigure 1
  • EP3070720B1 patent drawingFigure 2A~2B
  • EP3070720B1 patent drawingFigure 3A~3B

AI summary

A production method for an electronic component using an exterior packaging material containing a silicone resin comprises a step of dipping an element into an exterior packaging material containing a silicone resin to which aluminum hydroxide or magnesium hydroxide and a nonpolar solvent are added, an additive amount of the aluminum hydroxide or the magnesium hydroxide being controlled to a range of 60 [wt.%] or more to less than 70 [wt.%], a step of drying the exterior packaging material formed on a surface of the element to evaporate the nonpolar solvent and cause a silicone resin component to appear on a surface of the exterior packaging material, and a curing step of curing the exterior packaging material. As a result, the silicone resin can be reduced while maintaining the incombustibility and insulation withstand voltage of the exterior packaging material.