Color Filter Dye Exudation Prevention via Partitioning Walls

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Solution Overview

Problem

Conventional pigment dispersion methods for producing color filters, particularly for solid-state image sensors, face challenges in achieving high resolution and color purity due to pigment particle coarseness and dye exudation during heat treatment, leading to image quality degradation.

Innovation Solution

A method involving the formation of a colored pattern using a curable composition containing a dye, polymerizable monomer, and organic solvent, followed by irradiation with specific wavelengths of light to cure a transparent protective film, preventing dye exudation and enhancing color purity and definition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a high dye concentration is used to reduce film thickness and improve light-condensing properties, then color density and light-condensing properties are improved, but dye exudation during heat treatment increases, deteriorating color purity and image definition

Engineering Contradiction:

Improvecolor purity and image definitionVSAvoiddye exudation

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

A partitioning wall structure is introduced as an intermediary element between adjacent colored pixels. This partitioning wall prevents direct contact and mixing of dyes from different color regions, thereby preventing dye exudation from deteriorating color purity. The partitioning wall acts as a physical barrier that maintains color separation while allowing the use of high dye concentration for improved light-condensing properties.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The color filter structure is segmented into distinct regions including colored pixels and partitioning walls. This segmentation separates the dye-containing colored regions from each other using partitioning wall regions, preventing dye migration between adjacent colors. The segmentation maintains color purity while enabling high dye concentration within each isolated colored pixel region.

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If conventional pigment dispersion method is used, then positioning accuracy is high and large size production is suitable, but resolution cannot be further increased and color uniformity is poor due to coarse pigment particles

Engineering Contradiction:

Improveresolution and color uniformityVSAvoidprocess complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The conventional mechanical pigment dispersion method is replaced with a photolithographic patterning process. Instead of relying on mechanical mixing and dispersion of pigment particles, the invention uses light-based photolithography to precisely pattern colored regions. This substitution enables higher resolution and better color uniformity by eliminating the limitations of coarse pigment particles while maintaining positioning accuracy through optical alignment.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If heat treatment is applied to cure the protective film, then protective film curing is achieved, but dye exudation from colored patterns occurs, deteriorating color hue and contrast

Engineering Contradiction:

Improveprotective film integrityVSAvoidcolor hue and contrast

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The partitioning wall structure is formed in advance before the heat treatment curing process. This preliminary structural preparation creates physical barriers that prevent dye exudation during the subsequent heat treatment. By establishing the partitioning walls before curing, the invention ensures that dye migration is prevented while the protective film is being cured, thereby maintaining color hue and contrast integrity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The partitioning wall structure provides preliminary protection against the harmful effect of dye exudation during heat treatment. By pre-establishing these barrier structures, the invention counteracts the potential negative impact of heat-induced dye migration before it can occur, thereby preserving color purity and image definition throughout the curing process.

Inventive Principle:

Principle #9Preliminary anti-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

This method effectively produces color filters with high color purity and definition, suitable for solid-state image sensors with small pixel sizes, by suppressing dye exudation and improving light-condensing and color separation properties.

Implementation Method 1

a colored curable composition containing a dye, a polymerizable monomer and an organic solvent; (b) forming a transparent protective film on the colored pattern; and (c) irradiating at least the transparent protective film with light

Methodology Applied

Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentUS8968973B2Color filter and production method thereof, and solid-state image sensor using the same

Publication Date: 2015.03.03 FUJIFILM CORP

AI summary

A method of producing a color filter includes (a) forming a colored pattern on a substrate by exposing and developing a colored curable composition containing a dye, a polymerizable monomer and an organic solvent, (b) forming a transparent protective film on the colored pattern, and (c) irradiating at least the transparent protective film with light after forming the transparent protective film on the colored pattern.