Wavelength Conversion Module Ceramic Intermediate Layer Thermal Expansion

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current projection devices face challenges with the phosphor wheel's temperature resistance, thermal conductivity, and adhesion issues due to the use of organic glue and ceramic substrates, leading to reduced brightness and reliability.

Innovation Solution

A wavelength conversion module is designed with a ceramic substrate, a ceramic intermediate layer, and a ceramic reflection layer, where the thermal expansion coefficient of the intermediate layer bridges the gap between the substrate and reflection layer, enhancing adhesion and preventing thermal expansion-related issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If organic glue is used to attach the phosphor sheet to the heat dissipation substrate, then the phosphor wheel can be assembled, but the thermal conductivity is limited (less than 0.5 W/mk) and temperature resistance is limited (within 300°C)

Engineering Contradiction:

Improvetemperature resistanceVSAvoidheat dissipation capability

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent removes the organic glue layer from the structure and replaces it with a metal substrate that provides both mechanical support and thermal conduction. This extraction of the problematic organic component eliminates the thermal conductivity limitation while maintaining the structural integrity needed for assembly.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the material parameter of the substrate from organic (glue) to inorganic (metal), fundamentally altering the thermal conductivity parameter from <0.5 W/mk to significantly higher values, thereby enabling effective heat dissipation while maintaining temperature resistance above 300°C.

Inventive Principle:

Principle #35Parameter changes

2Temperature

If a ceramic substrate with high thermal conductivity (aluminum nitride) is used, then heat dissipation is improved, but the difference in thermal expansion coefficients causes poor adhesion and cracks

Engineering Contradiction:

Improveheat dissipation capabilityVSAvoidadhesion quality

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent introduces a transition layer between the metal substrate and the phosphor sheet that serves as an intermediary. This layer has thermal expansion properties that bridge the gap between the metal substrate and the ceramic/phosphor materials, preventing cracks while maintaining thermal conduction pathways.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention uses a composite structure combining metal substrate with a transition layer, creating a multi-material system that leverages the high thermal conductivity of metal while compensating for thermal expansion mismatches through the intermediate layer's properties.

Inventive Principle:

Principle #40Composite materials

3Illumination intensity

If high laser power is used to increase brightness, then the luminous efficiency is improved, but the heat accumulation deteriorates the glue and reduces reliability

Engineering Contradiction:

ImprovebrightnessVSAvoidglue durability

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The patent removes the organic glue component that degrades under high temperature, replacing it with a metal substrate structure that can withstand high laser power without deterioration, thereby enabling sustained high brightness operation.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical bonding function of organic glue with the structural integrity of a metal substrate system, eliminating the chemical degradation issue while maintaining the mechanical attachment needed for high-power operation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 design improves the structural reliability and service life of the wavelength conversion module, resulting in favorable projection quality and competitiveness for the projection device.

Implementation Method 1

the wavelength conversion layer is disposed on the ceramic reflection layer to receive the excitation beam

Methodology Applied

Scientific EffectWavelength conversion: Photoluminescence

Data Source

PatentUS11762269B2Wavelength conversion module and projection device

Publication Date: 2023.09.19 CORETRONIC CORPORATION

AI summary

The disclosure provides a projection device with a wavelength conversion module including a ceramic substrate, a ceramic intermediate layer, a ceramic reflection layer, and a wavelength conversion layer. The ceramic reflection layer is disposed on the ceramic intermediate layer disposed on the ceramic substrate. The thermal expansion coefficient of the ceramic intermediate layer ranges from the thermal expansion coefficient of the ceramic substrate and the thermal expansion coefficient of the ceramic reflection layer. The wavelength conversion layer is disposed on the ceramic reflection layer. With the wavelength conversion module and the projection device, separation or gaps between the ceramic substrate and the ceramic reflection layer caused by a significant difference of the thermal expansion coefficients is prevented, the adhesion between the ceramic substrate and the ceramic reflection layer is further improved, the service life and the structural reliability of the wavelength conversion module are improved.