Phosphor Substrate Laminate for Stable LED Light Color and Low Warpage

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Solution Overview

Problem

Existing LED lighting devices cannot adjust the emitted light color and lack a clear substrate configuration, leading to warpage issues due to heat generation from light emitting elements.

Innovation Solution

A light emitting substrate with a phosphor layer on an insulating substrate containing bismaleimide resin and glass cloth, where light emitting elements are mounted, featuring a specific electrode configuration and thermal expansion management to prevent warpage and stabilize light emission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a reflective material is provided on the substrate surface to improve light emitting efficiency, then light emitting efficiency is improved, but the substrate configuration becomes unclear and warpage issues occur

Engineering Contradiction:
Improvelight emitting efficiencyVSAvoidsubstrate configuration clarity
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The patent employs a composite substrate structure consisting of a core substrate with specific insulating layers and conductor layers laminated thereon. This composite construction provides both the structural stability needed to prevent warpage and the optical properties for efficient light emission, resolving the contradiction between improving light efficiency and maintaining clear substrate configuration.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent specifies precise parameter ranges for the substrate materials, including the core substrate thickness (0.5-2.0 mm), insulating layer thickness (10-50 μm), and conductor layer thickness (5-20 μm). By controlling these parameters within specific ranges, the substrate maintains dimensional stability to prevent warpage while ensuring adequate light transmission and reflective properties.

Inventive Principle:
Principle #35Parameter changes

2Power

If light emitting elements are mounted on the substrate, then light emission function is achieved, but heat generation causes warpage of the substrate

Engineering Contradiction:
Improvelight emission functionVSAvoidsubstrate warpage
Core Design Contradiction:
PowerVSStability of the object's composition

Solution Approach 1:

The patent addresses thermal expansion by selecting materials with compatible thermal expansion coefficients and designing a multi-layer substrate structure that can accommodate thermal stress. The core substrate and laminated layers are chosen to have matched thermal properties, preventing differential expansion that would cause warpage during operation.

Inventive Principle:
Principle #37Thermal expansion

Solution Approach 2:

The patent transitions from a simple single-layer substrate to a multi-dimensional laminated structure with core substrate, insulating layers, and conductor layers stacked in different dimensions. This layered architecture provides thermal management pathways and structural rigidity that prevent warpage while maintaining light emission functionality.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If the substrate structure is simplified to reduce manufacturing complexity, then ease of manufacture is improved, but warpage suppression and thermal management capabilities are reduced

Engineering Contradiction:
Improvesubstrate structure simplicityVSAvoidwarpage suppression
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent divides the substrate into functionally segmented layers: a core substrate providing structural support, insulating layers providing electrical isolation and dimensional stability, and conductor layers providing electrical connectivity and thermal management. This segmentation allows each layer to be optimized for its specific function while maintaining overall manufacturing feasibility through standardized lamination processes.

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

The solution effectively suppresses warpage and stabilizes light emission by managing thermal expansion and heat dissipation, allowing for adjustable light color and reduced glare.

Implementation Method 1

a phosphor layer which is disposed on the front face of the insulating substrate and includes a phosphor

Methodology Applied
Scientific EffectPhosphorescence: Phosphorescence

Data Source

PatentEP3905345B1Light-emitting substrate, and lighting device
Publication Date: 2024.01.24 DENKA CO LTD
  • EP3905345B1 patent drawingFigure 1A
  • EP3905345B1 patent drawingFigure 1B
  • EP3905345B1 patent drawingFigure 1C

AI summary

A phosphor substrate according to the present invention is a phosphor substrate having a plurality of light emitting elements mounted on one surface, and includes an insulating substrate, a first electrode group which is disposed on one surface of the insulating substrate and includes a plurality of electrodes bonded to the plurality of light emitting elements, 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, and the insulating substrate contains a bismaleimide resin and glass cloth.