Modular Wavelength Conversion Device Ceramic Substrates

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Solution Overview

Problem

Existing wavelength conversion devices using mirror-surface metal substrates face challenges in high temperature stability, complex fabrication processes, and long production cycles due to the difficulty of coating and sintering multiple phosphor layers of different colors on large substrates.

Innovation Solution

The use of ceramic substrates and a modular design with diffuse reflection and wavelength conversion layers formed by sintering slurry materials, allowing for separate optimization of each module's processing conditions and reducing the complexity of the fabrication process by using different glass powders with varying softening points.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If mirror-surface metal substrates are used for wavelength conversion devices, then high reflectivity is achieved, but thermal stability deteriorates at high temperatures

Engineering Contradiction:
ImprovereflectivityVSAvoidthermal stability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent uses a composite structure consisting of a metal substrate with a ceramic coating layer. The metal substrate provides high reflectivity while the ceramic coating layer provides thermal stability and resistance to high temperatures, thus combining the advantages of both materials to resolve the contradiction between reflectivity and thermal stability.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If multiple phosphor layers of different colors are coated on large substrates, then multi-color wavelength conversion is achieved, but fabrication complexity increases

Engineering Contradiction:
Improvemulti-color conversion capabilityVSAvoidfabrication process complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent divides the wavelength conversion device into multiple independent segments or modules, each containing a specific phosphor layer for a particular color conversion. This segmentation allows each module to be fabricated separately with optimized processing conditions for that specific phosphor, then assembled into a complete multi-color device, thereby reducing the complexity of fabricating all phosphor layers simultaneously on a single large substrate.

Inventive Principle:
Principle #1Segmentation

3Quantity of substance

If multiple passes of blade coating and sintering are performed for different phosphor layers, then multi-color phosphor deposition is achieved, but production cycle lengthens

Engineering Contradiction:
Improvephosphor layer coverageVSAvoidproduction cycle speed
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent prepares phosphor slurries with optimized formulations in advance, including pre-mixed phosphor particles, binders, and solvents in precise ratios. This preliminary preparation allows the slurries to be applied directly to substrates without requiring multiple adjustment and re-coating passes, enabling more efficient single-pass or reduced-pass coating and sintering processes that deposit complete functional phosphor layers, thus shortening the production cycle while achieving full phosphor coverage.

Inventive Principle:
Principle #10Preliminary action

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

This approach enhances thermal stability, reduces production time, and allows for flexible and high-quality wavelength conversion devices with improved thermal management and cost-effectiveness by enabling separate processing of each phosphor layer under optimal conditions.

Implementation Method 1

The reflective layer is a diffuse reflection layer, formed by sintering a diffusing material slurry which includes white scattering particles

Methodology Applied
Scientific EffectDiffuse reflection: Scattering

Implementation Method 2

formed by sintering a diffusing material slurry which includes white scattering particles, a first glass powder and an organic carrier

Methodology Applied
Scientific EffectSintering: Sintering

Implementation Method 3

wavelength conversion layer, which are sequentially stacked together forming an integral unit

Methodology Applied
Scientific EffectWavelength conversion: Photoluminescence

Data Source

PatentEP3059493B1Manufacturing method for wavelength conversion device
Publication Date: 2021.06.02 APPOTRONICS CORP LTD
  • EP3059493B1 patent drawingFigure 1~2
  • EP3059493B1 patent drawingFigure 3
  • EP3059493B1 patent drawingFigure 4

AI summary

Disclosed is a manufacturing method for a wavelength conversion device, comprising: preparing a plurality of wavelength conversion modules (2a, 2b, 2c), each wavelength conversion module (2a, 2b, 2c) comprising a ceramic substrate (23), a reflecting layer (22) and a fluorescent powder layer (21), said layers being stacked sequentially and formed into one piece; installing and fixing the plurality of wavelength conversion modules (2a, 2b, 2c) on one surface of a base substrate. By arranging different fluorescent powders respectively on the different wavelength conversion modules (2a, 2b, 2c), a plurality of wavelength conversion modules (2a, 2b, 2c) can be produced separately at the same time, thereby significantly shortening the production cycle. Each such module is produced independently and is thus not subject to the restrictions of the characteristics of other fluorescent powders. This is beneficial for the optimization of the various processes, and a wavelength conversion device having optimal performance is thereby obtained.