Phosphor Substrate Structure for LED Color Tuning and Chromaticity Control

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Solution Overview

Problem

Existing LED lighting equipment configurations, such as those disclosed in CN 106163113 A, cannot adjust the emitted light color to be different from the light emitted by the light emitting element, limiting flexibility in light emission color adjustment.

Innovation Solution

A light emitting substrate comprising a phosphor substrate with a phosphor layer and electrode pairs, where the phosphor layer covers a significant portion of the substrate's front face, including areas other than the electrode pairs, allowing for the adjustment of light emission color through the use of phosphors with different correlated color temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a reflective material is provided on the substrate surface, then light emitting efficiency is improved, but the ability to adjust light emission color is limited

Engineering Contradiction:
Improvelight emitting efficiencyVSAvoidlight emission color adjustment
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by incorporating phosphors with different correlated color temperatures (CCT) into the encapsulating resin. By adjusting the ratio and types of phosphors (e.g., yellow phosphor with 560-580nm peak, red phosphor with 610-650nm peak), the light emission color can be tuned across different CCT ranges while maintaining the reflective substrate for efficiency. This resolves the contradiction by enabling color adjustment without sacrificing light emitting efficiency.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining multiple phosphors (yellow phosphor particles and red phosphor particles) within the encapsulating resin. This composite phosphor system allows simultaneous optimization of light emission efficiency (through reflective substrate) and color adjustability (through phosphor composition ratios), directly resolving the technical contradiction between efficiency and adaptability.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If multiple phosphors with different correlated color temperatures are used, then light emission color adjustability is improved, but chromaticity variation occurs

Engineering Contradiction:
Improvelight emission color adjustmentVSAvoidchromaticity variation
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by creating a uniform distribution of multiple phosphor types within the encapsulating resin that surrounds each LED chip. This ensures that different phosphors (yellow and red) are locally distributed in controlled proportions, allowing color adjustment while maintaining consistent chromaticity across the entire light emitting surface, thus reducing chromaticity variation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements preliminary action by pre-mixing phosphors with different correlated color temperatures in specific ratios within the encapsulating resin before LED mounting. This preliminary preparation ensures uniform phosphor distribution and consistent chromaticity output, preventing chromaticity variation while maintaining color adjustability through the selected phosphor composition.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If phosphor layer covers large area including electrode regions, then light emission color adjustment is improved, but electrode visibility and connection reliability may be affected

Engineering Contradiction:
Improvelight emission color adjustmentVSAvoidelectrode connection reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies segmentation by dividing the substrate surface into distinct functional regions: electrode pairs for electrical connection and phosphor-containing regions for light emission color adjustment. The encapsulating resin with phosphors is applied selectively to cover large areas for color adjustment while leaving electrode regions exposed or appropriately configured, ensuring both color adjustability and electrode connection reliability are maintained.

Inventive Principle:
Principle #1Segmentation

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

Enables the adjustment of light emission color from the phosphor substrate to be different from the light emitting element, reducing glare and alleviating chromaticity variations while improving light emission efficiency and heat dissipation.

Implementation Method 1

a phosphor layer which is excited by receiving light emitted from the LED element, to emit wavelength-converted light

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

a flat plate-like monocrystalline phosphor disposed away from the light-emitting element, which absorbs the blueish laser light and then radiates yellowish wavelength-converted light

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentEP3905348B1Light-emitting substrate, and lighting device
Publication Date: 2024.01.24 DENKA CO LTD
  • EP3905348B1 patent drawingFigure 1A
  • EP3905348B1 patent drawingFigure 1B
  • EP3905348B1 patent drawingFigure 1C

AI summary

A phosphor substrate of the present invention is a phosphor substrate having at least one light emitting element mounted on one surface, and includes an insulating substrate, at least one pair of electrode pair which is disposed on one surface of the insulating substrate and bonded to the light emitting element, and a phosphor layer which is disposed on one surface of the insulating substrate and includes a phosphor in which a light emission peak wavelength, in a case where light emitted by the light emitting element is used as excitation light, is in a visible light region.