Black Matrix Substrate with Reflective Walls for Stray Light Control
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Solution Overview
Problem
Existing display technologies face challenges in forming thick black matrix patterns and light reflective films with high optical density, leading to difficulties in preventing stray light from entering adjacent pixels, which affects contrast and color purity.
Innovation Solution
A black matrix substrate assembly is designed with a transparent substrate, a black matrix pattern, a resin wall pattern, a light reflective layer, and a transparent protective layer, where the light reflective layer includes aluminum or aluminum alloy, and the assembly is produced using a method involving photolithography and wet etching to form a light reflective dividing wall with precise dimensions and alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a thick black matrix pattern is formed using conventional photolithography with high optical density material, then light-shielding performance is improved, but exposure light transmission is blocked and pattern formation becomes difficult
Solution Approach 1:
The light-shielding function is divided into two segments: a black matrix layer for absorption and a reflective layer for blocking. This segmentation allows each layer to have optimized thickness and material properties, solving the contradiction between thick pattern formation and exposure light transmission.
Solution Approach 2:
The invention uses a composite structure combining a black matrix layer (with light-absorbing material) and a reflective layer (with high reflectivity material). This composite approach achieves superior light-shielding performance while maintaining manufacturability through conventional photolithography processes.
2Object-affected harmful factors
If a light-scattering layer with thickness of 10 μm or more is formed using photolithography, then light scattering performance is improved, but exposure light is scattered by particles causing larger openings than photomask
Solution Approach 1:
The light-scattering function is extracted from the photosensitive layer and placed in a dedicated light-scattering layer formed by a separate coating and drying process. This extraction eliminates the conflict between light scattering and photolithography pattern formation.
Solution Approach 2:
The invention transitions from forming light-scattering patterns through photolithography (2D planar pattern) to forming a uniform light-scattering layer through coating and drying (3D thickness control). This dimensional change allows light scattering without compromising pattern resolution.
3Manufacturing precision
If laser ablation is used to form metal film patterns, then high precision patterning is achieved, but damage to circuit board or LEDs occurs due to high temperature and contamination
Solution Approach 1:
The invention replaces the mechanical/thermal laser ablation process with a chemical wet etching process. This substitution eliminates high temperature and spattered contamination while achieving precise metal film patterning through selective etching.
Solution Approach 2:
The invention changes the etching parameters by using wet etching instead of laser ablation. This parameter change allows precise patterning at lower temperatures without the harmful effects of laser-induced thermal damage and contamination.
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 solution effectively reduces stray light entry, enhancing display contrast and color purity, and improving light usage efficiency in LED and organic EL displays.
Implementation Method 1
a light reflective layer comprising first reflective linear segments; and second reflective linear segments
Implementation Method 2
a black matrix pattern comprising: a first grid of first and second black linear segments
Data Source
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AI summary
A black matrix substrate assembly includes a transparent substrate, a black matrix pattern over a major surface of the transparent substrate, a first transparent resin layer covering the black matrix pattern, a resin wall pattern over the first transparent resin layer, and a light reflective layer over the resin wall pattern. The black matrix pattern includes a first grid of first and second black linear segments with a width Ax of each first segment in a first direction. The resin wall pattern includes a second grid of first and second wall linear segments with a width Dx of each first segment smaller than the width Ax in the first direction and the center line of each first segment aligned with that of the corresponding first black linear segment. The light reflective layer includes first and second reflective linear segments with a width Cx of each first segment larger than the width Dx in the first direction and the center line of each first segment aligned with that of the corresponding first black linear segment. The light reflective layer includes pairs of first brims for each first reflective linear segment, pairs of second brims for each second reflective linear segment, and a transparent protective layer including first and second protective linear segments and disposed over the light reflective layer. Each pair of first brims has a width Ex and located within the width Ax of the corresponding first black linear segment so as to be symmetric with respect to the center line of the corresponding first reflective linear segment. Each first protective linear segment has a width Bx greater than or equal to a first total width of the corresponding first reflective linear segment, the first total width of each first reflective linear segment being the sum of the width Cx and the widths Ex of the first brims.