Molding Wavelength Conversion Members Without Cutting

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Solution Overview

Problem

The existing methods for producing light transmissive elements and light emitting devices involve cutting large fluorescent sheets, which can lead to fluorescent particles protruding from the cut surfaces, penetrating the reflective member or reducing its thickness, causing light leakage.

Innovation Solution

A method that involves providing a holding member with smooth inner lateral surfaces, filling the holes with a wavelength conversion member containing fluorescent particles, molding it, and removing it without cutting, thereby preventing particle protrusion and maintaining the reflective member's thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If cutting is performed on large fluorescent sheet to singulate it, then individual light transmissive elements can be obtained, but fluorescent particles protrude from cut surfaces and cause light leakage

Engineering Contradiction:

Improvesingulation of fluorescent sheetVSAvoidlight leakage prevention

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by forming the wavelength conversion member (containing fluorescent particles) into the desired shape and size before it is needed in the final assembly. The molding process creates precisely shaped wavelength conversion members with smooth surfaces that prevent particle protrusion, eliminating the need for subsequent cutting operations that would cause light leakage.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent extracts the wavelength conversion member from the molding cavity after formation, obtaining individually shaped pieces without requiring cutting. This extraction process yields ready-to-use components with clean surfaces that prevent fluorescent particles from protruding and causing light leakage in the final light emitting device.

Inventive Principle:

Principle #2Taking out (Extraction)

2Productivity

If cutting is performed on large fluorescent sheet, then singulation is achieved, but reflective member thickness is reduced or penetrated

Engineering Contradiction:

Improvesingulation of fluorescent sheetVSAvoidreflective member thickness maintenance

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The wavelength conversion member is molded into its final shape and size before being attached to the reflective member. This preliminary formation ensures precise dimensions and smooth surfaces, eliminating the need for cutting operations that would compromise the reflective member's thickness and integrity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent segments the wavelength conversion member from the molding cavity into individual pieces through extraction rather than cutting. This segmentation process maintains the integrity of both the wavelength conversion member and the reflective member, preventing damage to the reflective member's thickness and structure.

Inventive Principle:

Principle #1Segmentation

3Productivity

If cutting blade is used to singulate fluorescent sheet, then individual elements are obtained, but fluorescent particles protrude and penetrate reflective member

Engineering Contradiction:

Improvesingulation processVSAvoidfluorescent particle protrusion

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the mechanical cutting system with a molding system. Instead of using a cutting blade to separate fluorescent sheet pieces, the wavelength conversion member is formed directly in the desired shape through molding, then extracted intact. This substitution eliminates the mechanical cutting action that causes fluorescent particles to protrude and penetrate the reflective member.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state and form of the wavelength conversion member from a continuous sheet requiring cutting to individually molded pieces with precise dimensions. By controlling the molding parameters (temperature, pressure, cavity shape), the process produces ready-to-use components with smooth surfaces that prevent particle protrusion, eliminating the harmful effects of cutting.

Inventive Principle:

Principle #35Parameter changes

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 allows for the production of light transmissive elements without cutting, preventing fluorescent particle protrusion and light leakage, while maintaining the integrity of the reflective member, thus enhancing the efficiency and quality of light emitting devices.

Implementation Method 1

a wavelength conversion member containing fluorescent particles

Methodology Applied

Scientific EffectFluorescence: Fluorescence

Data Source

PatentUS10084120B2Method of producing light transmissive element and method of producing light emitting device

Publication Date: 2018.09.25 NICHIA CORP

AI summary

A method of producing a light transmissive element includes providing a holding member including an upper surface and a plurality of holes, each of the plurality of holes having at least one inner lateral surface that is a substantially smooth surface and an opening in the upper surface of the holding member; filling the plurality of holes with a wavelength conversion member containing fluorescent particles and a light transmissive member such that the wavelength conversion member is in contact with the inner lateral surface of each of the plurality of holes; molding the wavelength conversion member; and taking out the wavelength conversion member from the holding member after the molding of the wavelength conversion member.