Polymer Dispersion Masks for Precise LED Layer Formation

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Solution Overview

Problem

Existing methods for forming layers on LEDs, such as phosphor converters, are complex, expensive, and incompatible with the materials or processes used in light-emitting devices, making them difficult to implement.

Innovation Solution

A method involving the use of a polymer dispersion layer with dispersed particles in a liquid solvent is applied to form a cured polymer layer selectively on masked areas, allowing for the deposition of a material layer only on exposed areas by drying and curing, followed by removal of the cured polymer from masked areas, thus enabling spatially selective layer formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If existing methods for forming layers on LEDs are used, then layer formation can be achieved, but the process becomes complex and expensive

Engineering Contradiction:
Improvelayer formation precisionVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent introduces a polymer dispersion layer as an intermediary masking layer that simplifies the overall process. This layer is applied to the substrate, patterned using simple techniques, and then removed to define the phosphor layer pattern. The intermediary layer mediates between the substrate and phosphor materials, enabling precise layer formation without complex direct patterning methods.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The polymer dispersion layer is applied and patterned before the phosphor layer is deposited. This preliminary action establishes the pattern template in advance, allowing subsequent phosphor deposition to follow the pre-defined pattern without requiring complex in-situ patterning during the phosphor application step.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If existing methods for forming layers on LEDs are used, then layer formation can be achieved, but the cost increases

Engineering Contradiction:
Improvelayer formation precisionVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The polymer dispersion layer serves as a disposable masking layer that is applied, used for patterning, and then removed. This temporary layer enables precise pattern transfer at low cost, as it can be applied using simple, inexpensive techniques and discarded after serving its patterning function, avoiding the need for expensive reusable masking systems.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The polymer dispersion layer acts as a cost-effective intermediary that enables precise phosphor layer formation without requiring expensive specialized equipment or materials. The intermediary approach allows standard, low-cost deposition and patterning techniques to achieve high precision that would otherwise require expensive specialized processes.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If existing methods for forming layers on LEDs are used, then layer formation can be achieved, but compatibility with LED materials and processes is poor

Engineering Contradiction:
Improvelayer formation precisionVSAvoidcompatibility with LED materials and processes
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent employs a polymer dispersion layer with specific parameters (solvent type, polymer composition, drying temperature, curing conditions) that are optimized to be compatible with LED materials and manufacturing processes. By adjusting these parameters, the method achieves precise layer formation while maintaining compatibility with heat-sensitive LED structures and existing LED fabrication workflows.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The polymer dispersion layer serves as a compatible intermediary that bridges the substrate and phosphor materials without interfering with LED materials or processes. The intermediary layer can be applied and removed using conditions that do not damage LED structures, enabling precise patterning while maintaining full compatibility with LED manufacturing.

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

This approach simplifies and cost-effectively forms layers on LEDs while being compatible with the devices and processes, ensuring precise and efficient deposition of materials like phosphor converters.

Implementation Method 1

drying and curing the polymer dispersion layer to form a cured polymer layer

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

drying and curing the polymer dispersion layer to form a cured polymer layer

Methodology Applied
Scientific EffectPhotopolymerisation: Photopolymerisation

Implementation Method 3

selectively removing the cured polymer layer such that the cured polymer layer is present on only one or more selected, masked areas

Methodology Applied
Scientific EffectAblation: Ablation

Data Source

PatentEP4423820B1Method with patterned deposition mask formed using polymer dispersed in a liquid solvent
Publication Date: 2025.10.22 LUMILEDS LLC
  • EP4423820B1 patent drawingFigure 1~2B
  • EP4423820B1 patent drawingFigure 2C
  • EP4423820B1 patent drawingFigure 2D

AI summary

A polymer dispersion layer is formed on a substrate or semiconductor light-emitting devices on the substrate. After forming the polymer dispersion layer, drying and curing the polymer dispersion layer forms a cured polymer layer. After curing and drying, with the cured polymer layer being present on only selected, masked areas of the substrate or light-emitting devices, and with other areas of the substrate or light-emitting devices lacking the cured polymer layer and remaining exposed, a material layer is formed on at least the exposed areas of the substrate or light-emitting devices. After forming the material layer, the cured polymer layer is removed from the masked areas, leaving the material layer on the exposed areas.