Curable Silicone Composition for Optical Semiconductor Sealing

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Solution Overview

Problem

Curable silicone compositions used in optical semiconductor devices face issues with crack formation and yellowing due to thermal aging, leading to degradation in adhesion and transparency, especially when exposed to temperatures above 200°C.

Innovation Solution

A curable silicone composition comprising an organopolysiloxane with alkenyl and aryl groups, silicon-bonded hydrogen atoms, and a metal atom such as V, Ta, Nb, or Ce, along with a hydrosilylation catalyst, which suppresses crack formation and yellowing, ensuring excellent reliability and transparency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a curable silicone composition is used for sealing optical semiconductor devices, then excellent rubber characteristics and transparency are achieved, but crack formation occurs during thermal aging at temperatures above 200°C

Engineering Contradiction:
Improvesealing performanceVSAvoidcrack resistance
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The invention changes the chemical composition parameters of the silicone system by introducing specific organopolysiloxanes with controlled molecular structures (containing SiO4/2 units, ViR2SiO1/2 units, and R3SiO1/2 units) and adjusting the ratio of hydrogen-bonded to cross-linked structures through controlled hydrosilylation reaction, thereby improving thermal stability and crack resistance while maintaining sealing performance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite silicone system combining multiple organopolysiloxane components with different functional groups (alkenyl, aryl, hydrogen atoms) that work synergistically to provide both immediate sealing characteristics and long-term thermal stability, preventing crack formation during aging

Inventive Principle:
Principle #40Composite materials

2Temperature

If an organopolysiloxane containing cerium is added to improve heat resistance, then thermal stability is enhanced, but yellow coloration occurs reducing transparency

Engineering Contradiction:
Improveheat resistanceVSAvoidtransparency
Core Design Contradiction:
TemperatureVSIllumination intensity

Solution Approach 1:

The invention applies local quality modification by introducing metal atoms (V, Ta, Nb, or Ce) at specific concentrations (20-2000 ppm) within the silicone polymer chains to locally enhance thermal stability without causing widespread yellow coloration, thereby maintaining overall transparency while improving heat resistance

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention optimizes the concentration parameter of metal atoms within a specific range (20-2000 ppm) to achieve the desired balance between thermal stability and transparency, preventing excessive yellow coloration while maintaining effective heat resistance

Inventive Principle:
Principle #35Parameter changes

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 effectively prevents crack formation and yellowing, maintaining excellent adhesion and transparency even after thermal aging, thereby enhancing the reliability of optical semiconductor devices.

Implementation Method 1

A curable silicone composition, which can be cured by a hydrosilylation reaction

Methodology Applied
Scientific EffectHydrosilylation reaction: Chemical Bonding

Data Source

PatentEP3045499B1Curable silicone composition, cured product thereof, and optical semiconductor device
Publication Date: 2018.10.24 DOW SILICONES CORP
  • EP3045499B1 patent drawingFigure 1~2
  • EP3045499B1 patent drawingFigure 3~4
  • EP3045499B1 patent drawingFigure 5~6

AI summary

The present invention relates to a curable silicone composition comprising: (A) an organopolysiloxane having at least two alkenyl groups and at least one aryl group in a molecule, (B) an organopolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule, (C) an organopolysiloxane having at least one aryl group in a molecule and containing a metal atom selected from the group consisting of V, Ta, Nb and Ce, and (D) a hydrosilylation-reaction catalyst. The present invention can provide the curable silicone composition, which does not develop a crack by thermal aging and further can form a cured material that exhibits less yellowing. Abstract (as published by WIPO) The present invention pertains to a curable silicone composition comprising at least: (A) an organo-polysiloxane having, per molecule thereof, two or more alkenyl groups and one or more aryl groups; (B) an organo-polysiloxane having, per molecule thereof, two or more silicon-bonded hydrogen atoms; (C) an organo-polysiloxane having, per molecule thereof, one or more aryl groups, and a metal atom selected from a group consisting of V, Ta, Nb and Ce; and (D) a hydrosilation reaction catalyst. The present invention is capable of providing a curable silicone composition capable of forming a cured product which exhibits minimal yellowing, without producing cracks caused by thermal aging.