Silicone Resin Composition for White LED Sealing
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Solution Overview
Problem
Conventional epoxy resin sealing materials used in white LEDs degrade due to ultraviolet exposure and heat, leading to yellowing and cracking, and are inadequate for lower wavelength light sources, with issues of insufficient adhesion and light transmission.
Innovation Solution
A silicone resin composition comprising specific polysiloxanes and a hydrosilylating catalyst, including opposite-terminals-sealed-with-vinyl-group-type silicone resins, alkenyl-group-containing polysiloxane, and hydro-group-containing polysiloxane, which provides enhanced adhesion, transparency, and resistance to ultraviolet light, while maintaining low viscosity for easy application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If epoxy resin sealing material is used in white LED, then initial light transmission is good, but it turns yellow during use due to ultraviolet exposure
Solution Approach 1:
The patent changes the chemical composition parameters by using phenyl-containing silicone resin instead of conventional epoxy resin, and by controlling the ratio of vinyl-group-containing polysiloxane to trialkoxysilane within 4:1 to 10:1. This parameter change provides both high light transmission and resistance to yellowing from ultraviolet exposure.
Solution Approach 2:
The patent creates a composite sealing material system combining phenyl-containing silicone resin with specific ratios of vinyl-group-containing polysiloxane and trialkoxysilane. This composite approach achieves synergistic effects where the material maintains excellent light transmission while gaining superior ultraviolet resistance and durability.
2Reliability
If phenyl-containing silicone resin is used to improve ultraviolet resistance, then resistance to yellowing improves, but adhesion becomes insufficient due to cure shrinkage
Solution Approach 1:
The patent controls the vinyl-group-to-trialkoxysilane ratio within 4:1 to 10:1 and uses 0.01 to 5 weight percent of a specific catalyst. These parameter optimizations balance the cure shrinkage to maintain adhesion while preserving the ultraviolet resistance provided by phenyl-containing silicone resin.
Solution Approach 2:
The patent introduces specific functional groups (vinyl groups and trialkoxysilane groups) at controlled concentrations to locally enhance adhesion properties without compromising the overall ultraviolet resistance. The catalyst system is also locally optimized to control the curing process and minimize shrinkage-induced adhesion loss.
3Ease of manufacture
If conventional resin composition is used, then manufacturing is simple, but sufficient adhesion cannot be secured due to cure shrinkage
Solution Approach 1:
The patent optimizes the ratio of vinyl-group-containing polysiloxane to trialkoxysilane within 4:1 to 10:1 and controls catalyst content at 0.01 to 5 weight percent. These parameter changes maintain a relatively simple manufacturing process while significantly improving adhesion by controlling cure shrinkage.
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 silicone resin composition achieves a cured product with high hardness, transparency, and excellent adhesion, preventing discoloration and cracking, making it suitable for white LED applications and other semiconductor devices.
Implementation Method 1
a vinyl-group-containing polysiloxane and trialkoxysilane are used in a condensation reaction
Implementation Method 2
a catalyst for use in the condensation reaction is used in an amount of 0.01 to 5 weight %
Data Source
AI summary
A silicone resin composition is provided, which includes polysiloxane including (PSA1), (PSA2), (PSB) and (PSC), and a hydrosilylating catalyst, wherein a weight ratio between (PSA2) and (PSA1) (w2/w1) is 0.03-0.2: