Phosphor Sheet Machinability via Partial Curing
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Solution Overview
Problem
Existing phosphor sheets for LED chips face challenges in machinability and adhesive properties, with difficulty in cutting and holing due to their semi-solid or flexible state, and lack of clear machinability before bonding, which affects the uniformity and efficiency of wavelength conversion.
Innovation Solution
A phosphor-containing sheet with a crosslinked silicone composition that undergoes a hydrosilylation reaction, providing a storage modulus of 0.1 MPa or more at room temperature for machinability and less than 0.1 MPa at elevated temperatures for adhesive bonding, using a specific formulation of organopolysiloxane, organotrisiloxane, and catalysts to achieve precise cutting and bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a phosphor sheet is made with cured silicone resin to provide structural stability, then the sheet maintains its shape and position, but the sheet becomes difficult to machine (cutting and holing become cumbersome)
Solution Approach 1:
The patent applies parameter changes by controlling the degree of curing of the silicone resin. The phosphor sheet is made with partially cured silicone resin, where the curing degree is specifically controlled to balance machinability and adhesive properties. This intermediate state allows the sheet to be machined more easily than fully cured resin while still maintaining sufficient structural integrity.
Solution Approach 2:
The patent introduces dynamic properties by making the silicone resin partially cured, creating a material that transitions between solid and semi-solid states. This dynamic characteristic allows the sheet to be flexible enough for machining operations yet stable enough to maintain its shape during handling and bonding processes.
2Ease of manufacture
If a phosphor sheet is made with uncured or semi-cured silicone resin to improve machinability, then cutting and holing become easier, but the sheet lacks sufficient adhesive property for bonding to LED chips
Solution Approach 1:
The patent resolves this contradiction by precisely controlling the curing degree parameter of the silicone resin. By adjusting the curing degree to a specific range, the material achieves an optimal balance where it is soft enough for easy machining but has sufficient adhesive properties for strong bonding to LED chips.
Solution Approach 2:
The partially cured silicone resin creates a dynamic material state that exhibits different properties under different conditions. The sheet remains relatively soft for machining operations but develops adequate adhesive strength when bonded to LED chips, effectively resolving the contradiction between machinability and adhesive property.
3Strength
If a phosphor sheet is made with fully cured silicone resin to ensure strong bonding, then adhesive property is improved, but the sheet becomes very difficult to perform cutting or holing with high precision
Solution Approach 1:
The patent applies parameter changes by controlling the curing degree of the silicone resin to an intermediate state. This partial curing allows the sheet to be machined with high precision while still maintaining sufficient adhesive properties for bonding, effectively resolving the contradiction between bonding strength and cutting precision.
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 phosphor sheet exhibits excellent machinability and adhesive properties, allowing for precise cutting and holing at room temperature and strong bonding at elevated temperatures, resulting in stable and uniform LED light emission with improved luminance and color consistency.
Implementation Method 1
a resin main component of the phosphor-containing sheet is a crosslinked product formed by subjecting a crosslinkable silicone composition containing at least the following compositions (A) to (D) to a hydrosilylation reaction
Implementation Method 2
a fluorescent material formed into a sheet for converting an emission wavelength of an LED chip
Data Source
AI summary
A phosphor-containing sheet having a storage modulus of 0.1 MPa or more at 25° C. and a storage modulus of less than 0.1 MPa at 100° C., wherein a resin main component of the phosphor-containing sheet is a crosslinked product formed by subjecting a crosslinkable silicone composition containing a specific composition to a hydrosilylation reaction. This phosphor-containing sheet provides a phosphor sheet having good shapability and high adhesive power as a phosphor sheet bonded to an LED chip as a wavelength conversion layer.