Silicone Resin Composition for Optical Semiconductor Encapsulation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Silicone resin compositions used for encapsulating optical semiconductor devices, such as LEDs, face issues with high gas permeability and corrosion of silver surfaces, leading to discoloration and reduced brightness, despite offering good light and heat resistance.

Innovation Solution

A silicone resin composition characterized by a vinyl silicone resin with a trifunctional cycloalkyl group, hydrogenorganopolysiloxane, a catalyst for addition reactions, and an adhesion promoter, which provides low gas permeability and improved discoloration resistance, enhancing the durability and reflective efficiency of encapsulated devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional silicone resin compositions are used for encapsulation, then light resistance and heat resistance are improved, but gas permeability increases causing corrosive gas to attack silver surfaces

Engineering Contradiction:

Improvelight resistance and heat resistanceVSAvoidgas permeability leading to silver surface corrosion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the silicone resin by incorporating specific amounts of phenyl groups (0.1-1.0 mmol/g) and aluminum oxide particles (0.1-10.0 wt%), which modifies the molecular structure and physical properties to reduce gas permeability while preserving thermal and optical stability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite material system combining silicone resin with phenyl-containing compounds and aluminum oxide particles, where the composite structure provides both the desired optical/thermal resistance and reduced gas permeability through the synergistic effects of the different components

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If silicone resin with high gas permeability is used, then encapsulation simplicity is maintained, but discoloration of the encapsulant occurs due to corrosive gas attack

Engineering Contradiction:

Improveencapsulation simplicityVSAvoiddiscoloration resistance

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent converts the potentially harmful interaction between gas and encapsulant into a beneficial outcome by using aluminum oxide particles and phenyl groups to trap and neutralize corrosive gases, transforming them from discoloration-causing agents into protected elements that extend encapsulant life

Inventive Principle:

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

Solution Approach 2:

Aluminum oxide particles and phenyl-containing compounds act as intermediary substances between the corrosive gas and the silicone resin matrix, serving as barriers that prevent direct contact and chemical reactions that would cause discoloration

Inventive Principle:

Principle #24Intermediary (Mediator)

3Illumination intensity

If traditional encapsulant materials are used, then initial brightness is achieved, but reflective efficiency decreases over time due to silver surface blackening

Engineering Contradiction:

Improveinitial brightnessVSAvoidbrightness maintenance over time

Core Design Contradiction:

Illumination intensityVSDuration of action of stationary object

Solution Approach 1:

The patent applies preliminary protective action by incorporating aluminum oxide particles and phenyl groups into the encapsulant formulation before the device operates, creating a pre-established barrier that prevents corrosive gas from reaching and blackening the silver surface, thereby maintaining reflective efficiency throughout the device lifetime

Inventive Principle:

Principle #9Preliminary anti-action

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 composition achieves low gas permeability and high anti-sulfuration characteristics, resulting in encapsulated optical semiconductor devices with excellent heat and light resistance, preventing discoloration and maintaining brightness over time.

Implementation Method 1

a catalyst for addition reaction

Methodology Applied

Scientific EffectAddition reaction: Chemical Bonding

Data Source

PatentUS8431953B2Silicone resin composition and an optical semiconductor device making use of the composition

Publication Date: 2013.04.30 SHIN ETSU CHEMICAL CO LTD

AI summary

[Object]To provide a silicone resin composition for optical semiconductor devices, which has a low gas permeability and high dependability.[Means for solution]The silicone resin composition of the present invention contains the following components (A) through (D):(A) an organopolysiloxane as shown in the following general formula (1) in which the number of alkenyl groups contained per one molecule is two or more(R1SiO3/2)x(R23SiO1/2)y(R22SiO2/2)z (1)(wherein R1 is a cycloalkyl group, R2 is either one kind of or more than one kind of substituted or non-substituted monovalent hydrocarbon group having 1-10 carbon atoms, x is 0.5-0.9, y is 0.1-0.5, z is 0-0.2, and x+y+z=1.0),(B) a hydrogen organopolysiloxane containing at least two SiH groups per one molecule,(C) a catalyst for addition reaction,(D) an adhesion promoter agent.