Chemically Amplified Resist Wall Formation for LCD
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Solution Overview
Problem
Existing methods for manufacturing wall electrode type liquid crystal display devices struggle to form walls with large tapered angles and aspect ratios, and to create satisfactory insulating and planarizing films, due to limitations with organic passivation resist materials that result in insufficient exposure, reflow, and hardening reactions.
Innovation Solution
The use of chemically amplified positive resist materials, which undergo post-exposure, pre-calcination, and main calcination processes, allows for the formation of walls with tapered angles of 70 degrees or larger and the creation of flat insulating and planarizing films, using the same material for both the wall structure and the insulating film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If organic passivation resist material (NQD positive resist) is used to form walls, then the wall formation process is simple, but the tapered angle cannot reach 60 degrees and the wall shape becomes unsatisfactory
Solution Approach 1:
The patent changes the material parameter from conventional NQD positive resist to chemically amplified positive resist, which fundamentally alters the resist's response to light and heat. This parameter change enables the wall tapered angle to reach 60 degrees or more while maintaining ease of manufacture through the same basic wall formation process.
2Length of stationary object
If coating film thickness is increased to form thicker walls, then the wall height requirement is met, but the exposure amount is sharply increased and sensitivity is lowered
Solution Approach 1:
The patent changes the resist material parameter to chemically amplified positive resist, which has different photochemical properties. This allows the coating film thickness to be increased to 2.5 μm or more for wall height requirements while maintaining adequate exposure sensitivity, as the chemically amplified resist responds more efficiently to exposure light.
3Ease of manufacture
If NQD positive resist is used for wall formation, then the process is straightforward, but the film is strongly colored and fading of exposure light is bad
Solution Approach 1:
The patent changes the photosensitizing agent parameter from NQD to the photosensitizing agent of chemically amplified positive resist. This parameter change results in a transparent or lightly colored film that does not strongly absorb exposure light, thereby improving light fading characteristics while maintaining process straightforwardness.
4Ease of manufacture
If organic PAS resist is used for insulating and planarizing film formation, then the process is simple, but reflow and hardening reaction occur simultaneously during heating, resulting in insufficient planarization
Solution Approach 1:
The patent changes the resist material parameter from organic PAS resist to chemically amplified positive resist for insulating and planarizing film formation. This parameter change allows the film to undergo controlled reflow during heating without simultaneous hardening reactions, achieving sufficient planarization quality while maintaining process simplicity.
5Manufacturing precision
If chemically amplified positive resist is used for wall formation with post-exposure, pre-calcination, and main calcination processes, then walls with tapered angles of 70 degrees or larger and high aspect ratios are formed, but the manufacturing process becomes more complex
Solution Approach 1:
The patent applies preliminary action by performing post-exposure and pre-calcination before the main calcination process. These preliminary steps prepare the chemically amplified positive resist by generating photo-acid and controlling molecular weight, enabling the subsequent main calcination to achieve high tapered angles (70 degrees or larger) and high aspect ratios while managing process complexity through systematic sequencing.
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 enables the formation of walls with high aspect ratios and flat insulating films, improving the manufacturing process by increasing sensitivity, reducing material costs, and achieving better planarization and durability.
Implementation Method 1
using a chemically amplified resist, applying the chemically amplified resist; and exposing and developing the chemically amplified resist
Implementation Method 2
performing post exposure by irradiating light on the entire remaining chemically amplified resist; performing pre-calcination at a temperature lower than a main calcination temperature; and performing a main calcination at a temperature higher than the pre-calcination temperature
Data Source
AI summary
In a method of manufacturing a liquid crystal display device in which a plurality of pixels are arranged in a matrix, each of the pixels has an insulator wall structure at a boundary of the pixels, and a wall electrode is provided at least at a side of the wall structure, the wall structure being formed by: using a chemically amplified resist as a material of the wall structure, a step of applying the chemically amplified resist; a step of exposing and developing the chemically amplified resist; a step of irradiating light on an entire surface to perform post exposure; a step of pre-calcinating the chemically amplified resist at a temperature lower than a main calcination temperature; and a step of performing main calcination at a temperature higher than a pre-calcination temperature.