Silsesquioxane Copolymer Resin for High-Resolution Display Lithography

The patent employs a composite resin composition comprising multiple polymer components (polymer 1 contributing to sensitivity, polymer 2 contributing to resolution, and polymer 3 as binder) along with specific photoinitiators and additives. This multi-component composite approach enables simultaneous achievement of high sensitivity (80-95%), high resolution (sub-5μm patterns), and improved adhesion, resolving the contradiction between manufacturing precision and composition complexity.

The patent assigns specific functional roles to different polymer components within the composition: polymer 1 (containing carboxylic acid groups) provides sensitivity and adhesion enhancement, polymer 2 (acrylic or methacrylic polymer) provides resolution and pattern fidelity, and polymer 3 serves as a binder. This functional differentiation at the component level enables optimization of multiple performance parameters simultaneously.

The patent utilizes specific parameter ranges for each component to achieve the desired balance: polymer 1 content at 10-50 wt% provides sufficient sensitivity without excessive heat generation, polymer 2 at 30-60 wt% ensures resolution while maintaining thermal stability, and polymer 3 at 5-20 wt% provides adequate binding. The photoinitiator concentration (1-10 wt%) and molecular weight parameters are also controlled to optimize the exposure-heat resistance trade-off.

The patent employs a photoinitiator system that enables complete polymerization within a short exposure time (high productivity), preventing degradation from prolonged exposure. The specific photoinitiators (Type I and Type II combination) are selected for their ability to rapidly initiate polymerization, allowing the resin to achieve full crosslinking and heat resistance quickly, effectively using a 'short-living' photoinitiator action to achieve long-term heat resistance.

The patent employs polymer 1 with carboxylic acid groups specifically for adhesion enhancement at the interface with underlying layers, while polymer 2 and polymer 3 maintain the bulk optical properties. The carboxylic acid-containing polymer is present at 10-50 wt%, sufficient to provide strong adhesion without compromising the overall transparency of the coating, as it is distributed throughout the matrix rather than forming a separate opaque phase.

The composite resin system combines polymers with different functional properties: polymer 1 contributes adhesion and sensitivity, polymer 2 contributes resolution and optical clarity, and polymer 3 provides mechanical binding. This composite approach allows the formulation to achieve both high light transmittance (for display applications) and strong adhesion (for device reliability) simultaneously, as each component compensates for the limitations of others.

The patent formulates the resin composition with pre-balanced component ratios and molecular weight distributions that enable uniform pattern formation during direct patterning. The polymers are selected and proportioned to achieve optimal viscosity and flow characteristics before the patterning process, allowing the resin to self-level and form uniform patterns without requiring additional processing steps. The photoinitiator system is also pre-optimized to ensure uniform curing across the pattern area.

The patent controls critical parameters including the molecular weight of polymers (affecting viscosity and flow), the ratio of polymer components (affecting crosslinking density and pattern fidelity), and the photoinitiator concentration (affecting cure uniformity). By optimizing these parameters within specific ranges, the resin achieves excellent pattern uniformity and minimal residual film thickness variation, making direct patterning feasible with high precision.