Hydrogenated Epoxy Resin for LED Encapsulation
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Solution Overview
Problem
Current encapsulation materials for LEDs, such as epoxy and silicone resins, face issues with yellowing due to heat generation, brittleness, poor light extraction efficiency, and inadequate contact with polyamide and silver, leading to reliability concerns and coloration problems.
Innovation Solution
A new liquid organosilicon compound with a cage-type silicon structure is developed, which can be thermally hardened to form a resin composition that provides excellent refractive index, heat resistance, transparency, and crack resistance, and maintains close contact with LED substrates and electrodes without the need for solvents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If aromatic epoxy resin with alicyclic acid anhydride is used for encapsulation, then the resin hardens effectively, but the alicyclic acid anhydride is easily discolored by acid and the resin base requires a long hardening time
Solution Approach 1:
The patent changes the chemical composition parameters by using hydrogenated epoxy resin instead of aromatic epoxy resin, and selecting specific hardening agents (aliphatic polyamine or amide) that resist acid-induced discoloration. This parameter change maintains effective hardening while preventing the discoloration problem.
2Adaptability or versatility
If cationic polymerization hardening resin is used for encapsulation, then the resin can be applied, but the hardened resin is very brittle and easily develops crack destruction by cold & hot cycle test
Solution Approach 1:
The patent changes the resin base parameter from cationic polymerization hardening resin to hydrogenated epoxy resin hardening by amine or amide hardening agents. This fundamental parameter change produces a hardened resin that is less brittle and maintains reliability under thermal cycling conditions.
3Temperature
If phenyl silicone resin is used for encapsulation, then the refractive index is satisfactory and heat resistance is superior, but the resin is not enough to respond to achieving high power of LED
Solution Approach 1:
The patent uses hydrogenated epoxy resin as the base material, which combines the advantages of both phenyl silicone resin (heat resistance) and other materials (high power capability). This composite approach creates a hardened resin that achieves both heat resistance and high power LED compatibility.
4Object-affected harmful factors
If methyl silicone resin is used for encapsulation, then heat resistance and light resistance are superior, but the refractive index is low and light extraction efficiency is poor
Solution Approach 1:
The patent changes the resin base parameter from methyl silicone resin to hydrogenated epoxy resin, which has a higher refractive index that improves light extraction efficiency. The hydrogenation process maintains good light resistance while achieving the necessary optical properties for efficient LED operation.
5Object-affected harmful factors
If silicone resin is used for encapsulation material, then yellowing by heat generation is reduced, but the hardened material has poorer close contact with polyamide resin and silver, causing peeling by heat shock
Solution Approach 1:
The patent changes the resin base parameter from silicone resin to hydrogenated epoxy resin, which provides better adhesion to polyamide resin and silver substrates. The hydrogenated structure maintains resistance to thermal yellowing while the epoxy chemistry enables strong bonding to common LED substrates and electrodes.
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 hardened material exhibits high refractive index, transparency, and resistance to thermal yellowing, ensuring reliable encapsulation and improved performance in LED applications with enhanced physical stability and optical properties.
Implementation Method 1
a hardening agent for the organosilicon compound and a thermosetting resin composition comprising the organosilicon compound and the hardening agent, and a hardened material obtained by thermally hardening the thermosetting resin composition
Implementation Method 2
a cage-type silsesquioxane derivative... resistance to thermal yellowing
Data Source
AI summary
To provide a silicone resin-based thermosetting resin composition that can obtain a hardened material having a high refractive index and a good heat resistance. A solution is a liquid organosilicon compound represented by general formula (1) as described below: (1) wherein, X is each independently a group represented by formula (I), formula (II) or formula (III) as described below, and when the number of the group represented by formula (I) per one molecule of the liquid organosilicon compound represented by general formula (1) (or the number of groups per one mean molecule of the compound when the compound is a mixture having a different ratio for the group represented by formula (I), the group represented by formula (II) and the group represented by formula (III) ) is defined as a, the number of the group represented by formula (II) per one molecule thereof is defined as b, and the number of the group represented by formula (III) per one molecule thereof is defined as c, 0 ≤ a ≤ 3.5, 0 ≤ b ≤ 3.5, and 0 ≤ c ≤ 1 are obtained, and also a + b + 2c = 4 is obtained: wherein, R1 is each independently a group selected from alkyl having 1 to 4 carbons, cyclopentyl and cyclohexyl, R2 and R3 are each independently a group selected from alkyl having 1 to 4 carbons, cyclopentyl, cyclohexyl and phenyl, m and n are the number of repetitions of -OSi(R3)2-, and a mean value satisfying 1 to 50.