Light-emitting Device Ceramic Wavelength Conversion Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light-emitting devices with phosphor-based wavelength conversion parts face issues of color unevenness and durability due to phosphor settling and degradation from light and heat emission, and previous solutions have not adequately addressed these problems, particularly with silicone and epoxy resins, which lack sufficient heat and light resistance and have complex configurations.
Innovation Solution
A light-emitting device with a wavelength conversion part featuring a light-transmissive ceramic layer containing a phosphor, layered silicate mineral, and inorganic particulate, where the phosphor is evenly dispersed within the ceramic layer, enhancing heat resistance and film strength while suppressing phosphor settling and color unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a transparent resin is used to seal the LED chip and phosphor, then the phosphor can be contained and protected, but the phosphor settles due to gravity causing color unevenness
Solution Approach 1:
The patent changes the physical parameter of viscosity by using a high-viscosity resin (100-10,000 cP) to suppress phosphor settling. This parameter change directly addresses the contradiction by maintaining phosphor containment while preventing settlement-induced color unevenness through increased resin viscosity.
Solution Approach 2:
The patent creates a composite sealing material by combining resin with specific viscosity modifiers and potentially other additives to achieve the optimal viscosity range. This composite approach allows the sealing material to simultaneously provide containment, maintain phosphor dispersion uniformity, and prevent settling.
2Stability of the object's composition
If silicone resin is used to suppress phosphor settling, then phosphor dispersion is improved, but the sealing material degrades due to light and heat emission
Solution Approach 1:
The patent changes the chemical composition parameters of the resin to achieve high viscosity without using silicone-based materials. By selecting resins with specific chemical structures that provide high viscosity but resist photodegradation and thermal degradation, the patent simultaneously improves phosphor dispersion stability and extends sealing material durability under light and heat emission.
3Strength
If epoxy resin or other conventional resins are used, then the sealing material provides good adhesion, but the heat resistance and light resistance are insufficient
Solution Approach 1:
The patent develops a composite resin system that combines base resin with specific additives and modifiers to achieve both strong adhesion and high heat/light resistance. The composite formulation includes high-viscosity resin components that maintain adhesion while providing enhanced thermal and optical stability, overcoming the limitations of conventional epoxy and other standard resins.
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 solution effectively prevents phosphor settling and degradation, ensuring long-term durability and uniform light emission by using a ceramic layer with a specific composition and structure that maintains strength and viscosity, reducing color unevenness and enhancing the overall performance of the light-emitting device.
Implementation Method 1
when the layered compound recited in Patent Citation 3 is added as an anti-settling agent for the phosphor, the dispersion state of the phosphor is stabilized and there is the possibility of reducing the occurrence of color unevenness
Implementation Method 2
a wavelength conversion part including a phosphor for converting the wavelength of light emitted from the light-emitting element
Implementation Method 3
a sealing material which turns into a ceramic after being heated is used to seal in the LED chip and thereby improve the heat resistance and light resistance of the LED chip
Data Source
AI summary
A light-emitting device (100) is provided with a metal part (2) atop a planar LED substrate (1), and an LED element (3) is disposed atop the metal part (2). A glass substrate (5) is provided to an upper surface of the LED element (3), and a wavelength conversion part (6) is formed on an upper surface of the glass substrate (5). The wavelength conversion part (6) comprises a light-transmissive ceramic layer formed by heating a mixture containing a phosphor, an organometallic compound, a layered silicate mineral, an inorganic particulate, an organic solvent, and water.