Photosensitive Transfer Material for LED Light Shielding

Solution Overview

Problem

Existing light shielding materials for LED arrays suffer from density unevenness and light leakage due to film thickness issues, particularly at the hole ends of optical elements, which affects the rectangularity of the pattern formed.

Innovation Solution

A photosensitive transfer material with an infrared curing photosensitive layer, having a transmittance of 0.1% or more at 830 nm and an optical density of 3.0 or more at 550 nm, including a colorant, an infrared absorber, and a polymerization initiator, such as an onium salt compound, to improve pattern rectangularity and light shielding effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a light shielding layer is formed by coating black ink using conventional methods (ink jet, spin coating, slit coating), then the manufacturing process is simple, but film thickness unevenness occurs causing density unevenness and poor appearance

Engineering Contradiction:

Improvefilm thickness uniformityVSAvoidmanufacturing process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The black ink is applied to a release film first, dried to form a uniform film, and then transferred to the substrate. This preliminary formation on a separate film allows for better control of film thickness uniformity before final application

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A release film is introduced as an intermediary carrier to temporarily hold the black ink layer during the drying and transfer process, enabling better film formation control

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the photosensitive layer has high optical density at 550 nm to improve light shielding, then light leakage is reduced, but infrared curing effectiveness may be compromised

Engineering Contradiction:

Improvelight leakageVSAvoidcuring effectiveness

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The photosensitive layer is designed with different optical properties at different wavelengths: high optical density at 550 nm for visible light shielding, and high transmittance at 830 nm for infrared curing. This wavelength-specific optimization allows both requirements to be satisfied simultaneously

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The optical transmission characteristics of the photosensitive layer are optimized by selecting specific pigments and polymers that provide high absorption at 550 nm while maintaining high transmittance at 830 nm, enabling dual functionality

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the transmittance at 830 nm is increased to improve infrared curing, then curing effectiveness improves, but visible light shielding performance may deteriorate

Engineering Contradiction:

Improvecuring effectivenessVSAvoidvisible light shielding

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The photosensitive layer is designed with different optical properties at different wavelengths: high optical density at 550 nm for visible light shielding, and high transmittance at 830 nm for infrared curing. This wavelength-specific optimization allows both requirements to be satisfied simultaneously

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The optical transmission characteristics of the photosensitive layer are optimized by selecting specific pigments and polymers that provide high absorption at 550 nm while maintaining high transmittance at 830 nm, enabling dual functionality

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

The solution enhances the rectangularity of the pattern and reduces light leakage by ensuring adequate light penetration and uniform curing, leading to improved light shielding performance in LED arrays.

Implementation Method 1

the photosensitive layer has infrared curing properties

Methodology Applied

Scientific EffectInfrared curing: Photopolymerisation

Implementation Method 2

a transmittance of the photosensitive layer to light having a wavelength of 830 nm is 0.1% or more

Methodology Applied

Scientific EffectInfrared absorption: Absorption (EM radiation)

Implementation Method 3

an optical density of the photosensitive layer to light having a wavelength of 550 nm is 3.0 or more

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS20230097968A1Photosensitive transfer material, light shielding material, LED array, and electronic apparatus

Publication Date: 2023.03.30 FUJIFILM CORP

AI summary

A photosensitive transfer material including a temporary support and a transfer layer including a photosensitive layer, in which the photosensitive layer has infrared curing properties, and a transmittance of the photosensitive layer to light having a wavelength of 830 nm is 0.1% or more.