Phosphor Substrate Rear Electrode Structure for Warpage Suppression

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Solution Overview

Problem

Existing LED lighting devices cannot adjust the emitted light color using reflective materials and lack clarity in substrate rear surface configuration, leading to potential warpage issues due to heat generation from light emitting elements.

Innovation Solution

A light emitting substrate with a phosphor layer on an insulating substrate, featuring a second electrode group on the rear surface to stabilize the phosphor substrate and suppress warpage, while allowing for adjustable light emission color through a phosphor layer that converts the light emission peak wavelength to the visible region.

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 light emission color cannot be adjusted to different colors

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

Solution Approach 1:

The patent applies parameter changes by incorporating phosphor materials with different emission characteristics into the substrate. The substrate includes both reflective materials for efficiency and phosphors that can be excited by UV or blue LEDs to emit different wavelengths, enabling color adjustment while maintaining high light emitting efficiency through the reflective components.

Inventive Principle:
Principle #35Parameter changes

2Power

If light emitting elements are mounted on the substrate, then light emission function is achieved, but warpage occurs due to heat generation

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

Solution Approach 1:

The patent applies the counterweight principle by providing electrode patterns on both the front and rear surfaces of the substrate. These electrode patterns act as thermal counterweights that balance the heat distribution and mechanical stress caused by mounted light emitting elements, thereby preventing substrate warpage while maintaining full light emission functionality.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

3Ease of manufacture

If the rear surface configuration is not clearly defined, then manufacturing flexibility is maintained, but warpage suppression is insufficient

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidsubstrate warpage suppression
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by pre-configuring electrode patterns on the rear surface of the substrate before mounting light emitting elements. This preliminary configuration of the rear surface structure provides proactive warpage suppression through thermal balancing, while still allowing manufacturing flexibility in terms of electrode pattern design and fabrication methods.

Inventive Principle:
Principle #10Preliminary action

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 stabilizes light emission and suppresses warpage in the phosphor substrate, enabling adjustable light emission colors and efficient heat dissipation, improving the overall performance of the LED lighting device.

Implementation Method 1

a phosphor layer which is disposed on the front face of the insulating substrate and includes a phosphor and a binder, the phosphor layer being excited by irradiation light from the light emitting elements to emit light

Methodology Applied
Scientific EffectWavelength conversion: Fluorescence

Data Source

PatentEP3905346B1Light-emitting substrate, and lighting device
Publication Date: 2024.02.14 DENKA CO LTD
  • EP3905346B1 patent drawingFigure 1A
  • EP3905346B1 patent drawingFigure 1B
  • EP3905346B1 patent drawingFigure 1C

AI summary

A phosphor substrate of 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, 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 light emitting element is used as excitation light, is in a visible light region, and a second electrode group which is disposed on the other surface of the insulating substrate and includes a plurality of electrodes.