Laser-Cleaved Wavelength Conversion Member for Stronger Adhesion

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Solution Overview

Problem

Existing methods for manufacturing optical members, such as wavelength conversion members, often struggle with achieving good adhesion between the optical member and a covering member, which can affect the performance and reliability of light emitting devices.

Innovation Solution

A method involving the preparation of a polycrystalline wavelength conversion member with phosphor particles, forming a modified portion inside the member using focused laser light, and then cleaving the member from the first surface side using the modified portion as a starting point, resulting in improved surface roughness and adhesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional cleaving methods are used without laser modification, then the manufacturing process is simpler, but the adhesion between the optical member and covering member is poor

Engineering Contradiction:

Improveadhesion between optical member and covering memberVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The laser light is applied before cleaving to pre-modify the internal structure of the optical member, creating a modified portion that serves as a starting point for cleavage. This preliminary action ensures that the cleaved surface has increased roughness that improves adhesion, without requiring complex post-processing steps.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces conventional mechanical cleaving methods with a hybrid approach that uses laser-induced modification followed by controlled mechanical cleavage. The laser creates internal stress modifications that guide the cleavage process, resulting in superior surface characteristics compared to pure mechanical methods.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If laser light is focused inside the wavelength conversion member to form a modified portion, then surface roughness and adhesion are improved, but the manufacturing process becomes more complex and time-consuming

Engineering Contradiction:

Improvesurface roughness of optical memberVSAvoidmanufacturing efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent changes the physical state of the optical member by using laser light to create a modified portion with altered internal structure. This parameter change in the material's internal configuration enables controlled cleavage that produces the desired surface roughness without requiring multiple processing passes.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The laser light induces phase transitions or structural changes in the material at the focused location, creating a modified portion that has different mechanical properties. This localized phase change serves as a controlled initiation point for cleavage, ensuring consistent surface roughness across production batches.

Inventive Principle:

Principle #36Phase transitions

3Reliability

If the wavelength conversion member is pressed to cleave with the modified portion as a starting point, then adhesion is improved, but the equipment requirements and process complexity increase

Engineering Contradiction:

Improveadhesion between optical member and covering memberVSAvoidcleaving equipment complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The modified portion created by laser irradiation acts as an intermediary that mediates between the laser energy and the mechanical cleavage process. This intermediate structure guides the cleavage propagation, ensuring that the force applied during pressing results in controlled fracture with the desired surface characteristics for improved adhesion.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 proposed method enhances the adhesion between the optical member and the covering member, improving the reliability and performance of light emitting devices by creating a surface with increased roughness, particularly through the formation of first and second regions on the lateral surfaces of the optical member.

Implementation Method 1

forming a modified portion inside the wavelength conversion member by focusing laser light inside the wavelength conversion member

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentUS20250040322A1Method of manufacturing optical member, and light emitting device

Publication Date: 2025.01.30 NICHIA CORP

AI summary

A method of manufacturing an optical member includes: providing a polycrystalline wavelength conversion member including phosphor particles and having a first surface and a second surface opposite to the first surface; forming a modified portion inside the wavelength conversion member by focusing laser light inside the wavelength conversion member; and cleaving the wavelength conversion member with the modified portion being a starting point, which includes pressing the wavelength conversion member from a first surface side.