LED Encapsulant Composition Balancing Adhesion and Light Transmittance
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Solution Overview
Problem
Existing LED encapsulants, such as epoxy resins, exhibit low light transmittance, poor heat resistance, and insufficient mechanical durability, particularly in the blue light or UV ray region, limiting their effectiveness in high-brightness LED applications.
Innovation Solution
A curable composition comprising a silicon compound with a hydrogen atom bonded to a silicon atom and a polymerization product of polyorganosiloxane with specific molar ratios of siloxane units, including a functional group with an aliphatic unsaturated bond, which can be cured through hydrosilylation, enhancing mechanical strength, light transmittance, and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If epoxy resin is used as LED encapsulant, then adhesive strength and mechanical durability are improved, but light transmittance in blue light or UV region and heat resistance deteriorate
Solution Approach 1:
The patent uses a composite material system combining polyorganosiloxane main chain with aromatic hydrocarbon side chains. The siloxane backbone provides mechanical strength and adhesive properties, while the aromatic side chains (containing phenyl or naphthyl groups) enhance light transmittance in blue/UV regions and heat resistance. This composite structure resolves the contradiction by integrating materials with complementary properties.
Solution Approach 2:
The patent changes the chemical composition parameters of the encapsulant by specifying precise molar ratios of different siloxane units (Formula 1: 10-40 mol%, Formula 2: 30-60 mol%, Formula 3: 30-70 mol%). By adjusting these compositional parameters, the material achieves optimal balance between mechanical durability and optical/thermal performance.
2Strength
If epoxy resin is used as LED encapsulant, then adhesive strength is improved, but heat resistance deteriorates
Solution Approach 1:
The patent employs a composite material structure where polyorganosiloxane provides thermal stability through its siloxane backbone, while aromatic side chains (phenyl/naphthyl groups) contribute high heat resistance. This composite approach maintains adhesive strength while achieving superior heat resistance compared to pure epoxy resin.
Solution Approach 2:
The patent achieves improved heat resistance by changing the chemical composition parameters - specifically incorporating siloxane units with aromatic side chains in controlled molar ratios (Formula 1: 10-40 mol%, Formula 2: 30-60 mol%, Formula 3: 30-70 mol%). This compositional adjustment raises the material's thermal stability while preserving adhesive properties.
3Ease of operation
If conventional siloxane composition is used, then processability is maintained, but mechanical strength and durability deteriorate
Solution Approach 1:
The patent changes the molecular structure parameters of the siloxane by introducing specific functional groups (vinyl, phenyl, naphthyl) and controlling the molar ratios of different siloxane units. The vinyl groups enable crosslinking for enhanced mechanical strength, while the aromatic groups improve durability. The controlled composition (Formula 1: 10-40 mol%, Formula 2: 30-60 mol%, Formula 3: 30-70 mol%) maintains processability.
Solution Approach 2:
The patent applies local quality by introducing vinyl functional groups at specific locations in the siloxane chain (3-10 mol% of total siloxane units). These localized vinyl groups provide crosslinking sites for enhanced mechanical strength without compromising the overall processability of the bulk material. The aromatic side chains are also locally distributed to enhance durability where needed.
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 provides a cured product with excellent mechanical strength, high light transmittance, and lasting durability, suitable for encapsulating photonic semiconductors in LED applications.
Implementation Method 1
One aspect of the present application provides a curable composition including components that can be cured by hydrosilylation, for example, a reaction between an aliphatic unsaturated bond and a hydrogen atom
Data Source
AI summary
Provided are a curable composition and its use. The curable composition exhibits excellent processability and workability before curing, and excellent light extraction efficiency, hardness, thermal and shock resistance, moisture resistance, gas permeability, and adhesiveness after curing. In addition, the curable composition may provide a cured product that exhibits long-lasting durability and reliability even under harsh conditions, and does not causing whitening and surface stickiness.