Photosensitive Resin Composition for Black Pixel Defining Layer
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Solution Overview
Problem
Existing photosensitive resin compositions used in display device manufacturing face challenges such as bubble defects, pin stains, and Mura phenomena during the VCD process due to high viscosity and inappropriate solvent use, which affect the quality of the black pixel defining layer.
Innovation Solution
A photosensitive resin composition is developed using a combination of two acetate solvents with a boiling point difference of 10° C. to 60° C., along with a polyamic acid-polyimide copolymer binder, organic and inorganic black pigments, and a photopolymerizable monomer, to improve solubility and reduce defects like bubble defects, pin stains, and Mura.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single solvent is used in the photosensitive resin composition, then the formulation is simple, but the solubility and processibility are insufficient leading to defects
Solution Approach 1:
The patent uses a composite solvent system comprising two specific acetate solvents (first acetate solvent and second acetate solvent) with different boiling points. This composite approach allows the formulation to achieve both good solubility for the binder resin and appropriate processibility during VCD, eliminating defects like pin stains and Mura while maintaining formulation complexity within acceptable limits.
Solution Approach 2:
The patent specifies precise parameter ranges for the solvent system: the first acetate solvent content is controlled at 5-60 wt% and the second acetate solvent at 40-95 wt%, with boiling point differences of 20-60°C between them. These parameter optimizations enable the composition to achieve optimal viscosity and processibility, resolving the contradiction between simplicity and performance.
2Stability of the object's composition
If high viscosity resin is used, then the composition is stable, but the processibility during VCD is poor causing defects
Solution Approach 1:
The patent controls the viscosity of the photosensitive resin composition within 50-500 cP at 25°C through optimized formulation parameters. The specific ratio of acetate solvents and the selection of binder resin content (1-30 wt%) enable the composition to maintain stability while achieving appropriate flow characteristics for VCD processing, thereby eliminating pin stains and improving manufacturability.
3Device complexity
If inappropriate solvent is used, then the formulation is simple, but bubble defects and pin stains occur during VCD
Solution Approach 1:
The patent employs a composite solvent system with two acetate solvents having different boiling points (difference of 20-60°C). This composite approach prevents bubble formation and pin stains during VCD by ensuring complete solvent evaporation and uniform drying, while the total solvent content is controlled at 65-95 wt% to maintain formulation simplicity.
Solution Approach 2:
The patent specifies that the first acetate solvent content should be 5-60 wt% and the second acetate solvent 40-95 wt%, with the boiling point difference controlled at 20-60°C. These parameter optimizations ensure that the solvent system provides adequate process time for VCD while evaporating completely without causing defects, resolving the contradiction between simplicity and reliability.
4Stability of the object's composition
If the boiling point difference between solvents is too small, then the solvent system is uniform, but Mura phenomenon and pin stains occur
Solution Approach 1:
The patent specifies that the boiling point difference between the first and second acetate solvents should be 20-60°C. This parameter optimization ensures that the solvents evaporate at different rates during VCD, preventing Mura phenomenon and pin stains while maintaining sufficient uniformity in the solvent system for stable processing.
5Strength
If the binder resin has high molecular weight, then the mechanical properties are good, but the solubility and pattern-forming capability deteriorate
Solution Approach 1:
The patent controls the weight average molecular weight of the binder resin between 3,000-20,000 g/mol. This parameter optimization ensures that the binder resin maintains adequate mechanical strength while achieving sufficient solubility in the acetate solvent system for proper pattern formation during VCD and development processes.
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 composition achieves improved processibility and defect reduction, ensuring high heat resistance, pattern-forming capability, and light-blocking properties, enhancing the reliability and quality of the black pixel defining layer in display devices.
Implementation Method 1
a photopolymerizable monomer; a photopolymerization initiator
Data Source
AI summary
A photosensitive resin composition, a black pixel defining layer, and a display device, the composition including a binder resin; a black colorant; a photopolymerizable monomer; a photopolymerization initiator; and a solvent, wherein the solvent includes a first acetate solvent and a second acetate solvent and a boiling point difference between the first acetate solvent and the second acetate solvent is about 10° C. to about 60° C.