Roll Brush with Gradient Bristle Properties for Uniform Substrate Cleaning
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Solution Overview
Problem
Existing substrate cleaning methods for liquid crystal display panels, particularly the brush method, are insufficient in cleaning the rear face of substrates uniformly, leading to non-uniform gaps between substrates and deteriorated display quality due to excessive stress and inadequate contact pressure distribution.
Innovation Solution
A substrate cleaning apparatus with a roll brush that increases in diameter, stiffness, or density from the edge to the center, allowing uniform contact pressure and effective cleaning without excessive stress, combined with a transporting unit to manage substrate warping and ensure comprehensive cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a roll brush is used to clean the rear face of the substrate, then mechanical removal of foreign objects is effective, but non-uniform contact pressure causes insufficient cleaning at the center and excessive stress at the edges
Solution Approach 1:
The roll brush is designed with non-uniform bristle properties where the central portion has higher stiffness and/or density compared to the end portions. This local differentiation ensures that the central area applies sufficient contact pressure for effective cleaning, while the end portions reduce stress to avoid substrate damage, thereby achieving uniform cleaning pressure distribution across the entire substrate surface
Solution Approach 2:
The brush is constructed with varying bristle parameters (stiffness and density) along its length. Specifically, the bristle stiffness and/or density increase from the end portions toward the central portion, creating a gradient that compensates for the natural pressure distribution pattern during rotation and ensures uniform contact pressure across the substrate surface
2Manufacturing precision
If the roll brush applies sufficient pressure to clean the center area, then cleaning effectiveness improves, but the substrate receives excessive stress causing warping
Solution Approach 1:
The roll brush employs different bristle characteristics at different locations: the central portion has higher stiffness and/or density to provide strong cleaning action, while the end portions have lower stiffness and/or density to minimize stress. This local quality differentiation allows effective cleaning at the center without causing excessive stress or warping at the edges
3Ease of manufacture
If a uniform roll brush is used, then manufacturing is simple, but cleaning uniformity deteriorates due to constant contact pressure
Solution Approach 1:
Instead of using a uniform roll brush, the invention employs a brush with deliberately varied bristle properties along its length. The central portion has higher stiffness and/or density while the end portions have lower stiffness and/or density. This non-uniform structure, while slightly more complex to manufacture, achieves uniform cleaning pressure distribution and significantly improves cleaning uniformity across the substrate
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 apparatus achieves uniform cleaning of entire substrates without excessive stress, maintaining alignment film integrity and enhancing display quality by ensuring uniform contact pressure across the substrate surface.
Implementation Method 1
a roll brush which touches a glass substrate 3 while rotating... the roll brush 10 touches the rear face of the glass substrate 3 while rotating
Implementation Method 2
removing foreign objects mechanically by the roll brush... mechanical section which moves the roll brush 10 up and down
Data Source
AI summary
Disclosed is a substrate cleaning apparatus including a brush cleaning unit which cleans a substrate by making a roll brush in contact with a surface of the substrate, and a transporting unit which conveys the substrate. The roll brush includes a bristle. At least one of a diameter of the roll brush, stiffness of the bristle, and density of the bristle becomes larger from an end portion of the roll brush to a central portion thereof.