Pixel Defining Layer Outgas Reduction via Post-Heat Treatment
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Solution Overview
Problem
Organic light emitting display devices face issues with pixel shrinkage, dark spots, and reduced lifespan due to high outgas and moisture content, which affect luminance and reliability, especially when the amount of outgas is 15 ppm or more and moisture is 50 ppm or more after post-heat treatment.
Innovation Solution
A method for preparing a pixel defining layer using a photosensitive resin composition that involves prebaking, exposure, development, and post-heat treatment at 210° C. to 300° C. for 30 to 120 minutes, with the goal of minimizing outgas to 15 ppm or less and moisture to 50 ppm or less, using a colorant with an average particle diameter of 20 nm to 110 nm, and a binder resin with specific molecular weight and structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If colored patterns are used to achieve vivid colors, then color display quality is improved, but outgas amount increases causing pixel shrinkage and dark spots
Solution Approach 1:
The patent changes the particle size parameter of colorants to 20-110 nm range and adjusts binder resin molecular weight to 10,000-100,000, which modifies the physical state and crosslinking behavior of the colored pattern, reducing outgas generation while maintaining color quality
Solution Approach 2:
The patent uses a composite photosensitive resin composition containing colorants, binder resins, and crosslinking agents that work together to achieve both vivid colors and low outgas emission through synergistic effects of the composite material system
2Illumination intensity
If colored patterns are used to achieve vivid colors, then color display quality is improved, but moisture content increases causing pixel shrinkage and electrode oxidation
Solution Approach 1:
The patent modifies the molecular weight parameter of binder resin to 10,000-100,000 and adjusts crosslinking density, which changes the moisture absorption characteristics and enhances moisture removal efficiency during post-heat treatment, reducing moisture content to 50 ppm or less
Solution Approach 2:
The patent creates a crosslinked network structure that acts as a barrier to moisture penetration, effectively creating an inert environment within the colored pattern that prevents external moisture absorption and internal moisture-related damage
3Reliability
If post-heat treatment is performed to remove moisture and outgas, then reliability is improved, but process time and energy consumption increase
Solution Approach 1:
The patent performs prebaking before the main post-heat treatment process to remove a portion of moisture and volatile organic compounds in advance, which reduces the burden on the subsequent post-heat treatment step and shortens the overall processing time while maintaining reliability
Solution Approach 2:
The patent designs the photosensitive resin composition to enable continuous moisture and outgas removal throughout the drying and curing processes, maintaining effective outgas venting and moisture removal throughout the entire post-heat treatment period rather than requiring extended treatment times
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 ensures vivid colors, increased display reliability, and extended lifespan by minimizing outgas and moisture, thereby preventing pixel shrinkage and dark spots, and enhancing the overall performance of the organic light emitting display device.
Implementation Method 1
a photosensitive resin composition is used, which has a crosslinking structure during a development process
Implementation Method 2
the moisture is removed through the post-heat treatment process
Data Source
AI summary
The present disclosure is not only to ensure vivid colors but also to increase display reliability and lifespan by implementing a colored pattern with low outgas amount and moisture content on an electrode substrate; in other words, since it may cause a decrease in luminance and a decrease in lifespan due to pixel shrinkage if the amount of outgas in the panel after post-heat treatment is 15 ppm or more, or the moisture content is 50 ppm or more, the present disclosure is to minimize the generation of outgas and the moisture content in the panel state by maintaining sufficient heat and time and generating sufficient fume in the post-heat treatment step in order to minimize the outgas amount and moisture content after completing the post-heat treatment process by including a colorant according to the present disclosure.