Light-Reflective Anisotropic Conductive Adhesive for LED Efficiency

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional light-emitting devices face reduced light emission efficiency due to absorption of light by gold wires and die-bonding adhesives, and increased production costs from requiring a light reflecting layer, along with low initial die shear strength in silicone resin-based anisotropic conductive adhesives.

Innovation Solution

A light-reflective anisotropic conductive adhesive comprising a thermosetting resin composition with glycidyloxyalkyl-alicyclic alkyl-modified organopolysiloxane, conductive particles coated with metal, and light-reflective insulating particles such as titanium oxide, which enhances light reflection and maintains high die shear strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a light reflecting layer is provided on the LED element to prevent light absorption, then light emission efficiency is improved, but production cost increases due to metal vapor deposition process

Engineering Contradiction:

Improvelight emission efficiencyVSAvoidproduction cost

Core Design Contradiction:

Loss of energyVSEase of manufacture

Solution Approach 1:

The patent combines the light reflecting function and the adhesive bonding function into a single material - the anisotropic conductive adhesive itself. The adhesive contains light-reflective particles (such as titanium oxide, aluminum oxide, or silver particles) dispersed within the resin matrix, allowing it to both bond the LED element to the substrate and reflect light back through the element without requiring a separate light reflecting layer.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The anisotropic conductive adhesive is designed to perform multiple functions simultaneously: electrical conduction in the horizontal direction, light reflection, and adhesive bonding. This multi-functional material eliminates the need for separate functional layers, reducing manufacturing steps and costs while maintaining or improving light emission efficiency.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If epoxy resin is used as binder resin for anisotropic conductive paste, then connection reliability is improved, but light transmittance deteriorates due to absorption in near ultraviolet to near infrared region

Engineering Contradiction:

Improveconnection reliabilityVSAvoidlight transmittance

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The patent changes the chemical composition parameter of the binder resin from epoxy resin to silicone resin. Silicone resin has superior light transmittance properties across the ultraviolet, visible, and near infrared regions compared to epoxy resin, while still providing adequate connection reliability when combined with the anisotropic conductive particles and light-reflective particles.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If silicone resin is used as binder resin, then light stability is improved, but initial die shear strength deteriorates

Engineering Contradiction:

Improvelight stabilityVSAvoidinitial die shear strength

Core Design Contradiction:

Stability of the object's compositionVSStrength

Solution Approach 1:

The patent creates a composite anisotropic conductive adhesive system combining silicone resin with specific ratios of conductive particles (such as metal particles or carbon particles) and light-reflective particles. This composite formulation enhances the mechanical strength and die shear resistance of the silicone resin-based adhesive while maintaining its light stability and resistance to yellowing over time.

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

Improves light-emitting efficiency by reflecting light without the need for a separate light reflecting layer, maintaining high die shear strength and luminous flux over long-term use, and reducing production costs.

Implementation Method 1

light-reflective insulating particles... The light-reflective anisotropic conductive adhesive reflects light without the need for a separate light reflecting layer

Methodology Applied

Scientific EffectLight reflection: Reflection

Implementation Method 2

a light-reflective anisotropic conductive adhesive used for anisotropic conductive connection of a light-emitting element to a wiring board, the light-reflective anisotropic conductive adhesive including a thermosetting resin composition containing a silicone resin and a curing agent

Methodology Applied

Scientific EffectThermosetting:

Implementation Method 3

anisotropic conductive connection of a light-emitting element to a wiring board... anisotropic conductive adhesive

Methodology Applied

Scientific EffectAnisotropic conduction:

Data Source

PatentEP2584015B1Light-reflecting anisotropically conductive adhesive and light emitting device

Publication Date: 2016.11.02 DEXERIALS CORP

AI summary

A light-reflective anisotropic conductive adhesive used for anisotropic conductive connection of a light-emitting element to a wiring board includes a thermosetting resin composition containing a silicone resin and a curing agent, conductive particles and light-reflective insulating particles. The light-reflective insulating particle is at least one kind of inorganic particles selected from the group consisting of titanium oxide, boron nitride, zinc oxide, silicon oxide, and aluminum oxide. The silicone resin is a glycidyloxyalkyl-alicyclic alkyl-modified organopolysiloxane.