Touch Sensor Light Shielding via Thin Dielectric Layers
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Solution Overview
Problem
Conventional touch sensor devices face issues with mura defects and reduced display quality due to the thick shielding layers used for light shielding, which create step heights between sensing and non-sensing regions, affecting the integrity of the touch panel display.
Innovation Solution
A touch sensor device structure incorporating a transparent substrate with a sensing region and a non-sensing region, featuring an inorganic dielectric material layer with a thin thickness (<0.3 μm) that partially covers the sensing electrode pattern layer, along with a reflective layer and a protective layer, to form a light shielding/decorative film that eliminates step heights and enhances display quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a thick shielding layer (more than 1 μm) is used for light shielding, then the light shielding effect is improved, but step heights are formed between the fan-out region and the sensing region, resulting in mura defects and reduced display quality
Solution Approach 1:
The shielding layer is divided into multiple thin layers (first shielding layer and second shielding layer) with different thicknesses and optical properties. The first shielding layer has thickness of 0.01-0.1 μm and the second shielding layer has thickness of 0.1-1.0 μm, allowing each layer to contribute differently to light shielding while minimizing step height formation.
Solution Approach 2:
Different regions of the shielding layer structure are assigned different thicknesses and materials. The first shielding layer covers the entire peripheral region including both fan-out and sensing regions, while the second shielding layer is selectively formed only in the fan-out region, providing localized light shielding where needed without creating step heights in the sensing region.
2Object-affected harmful factors
If a thick shielding layer is formed by wet process, then sufficient light shielding is achieved, but step heights are created that affect the integrity of the touch panel display
Solution Approach 1:
The shielding function is segmented into multiple thin layers deposited by different processes. The first shielding layer is formed by sputtering with thickness of 0.01-0.1 μm, and the second shielding layer is formed by screen printing with thickness of 0.1-1.0 μm, ensuring each layer is thin enough to avoid significant surface relief while collectively providing adequate light shielding.
Solution Approach 2:
An inorganic dielectric material layer with thickness of 0.01-0.5 μm is introduced as an intermediary between the substrate and the shielding layers. This dielectric layer serves as a base layer that facilitates the formation of thin shielding layers with uniform thickness, preventing the formation of large step heights while maintaining the light shielding function.
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 eliminates mura defects, improves display quality, and allows for various color options and reflective abilities, simplifying the fabrication process by integrating the light shielding/decorative film with the touch sensor device components.
Implementation Method 1
A light shielding/decorative film for a touch sensor device and a touch sensor device including the light shielding/decorative film are provided. The inorganic dielectric material layer has a first portion in the non-sensing region and a second portion in the sensing region
Implementation Method 2
allows for various color options and reflective abilities, simplifying the fabrication process by integrating the light shielding/decorative film with the touch sensor device components
Data Source
AI summary
A system for displaying images is provided. The system includes a touch sensor device including a transparent substrate having a sensing region and a non-sensing region adjacent to the sensing region. A sensing electrode pattern layer is on the transparent substrate in the sensing region. An inorganic dielectric material layer is on the transparent substrate. The inorganic dielectric material layer has a first portion in the non-sensing region and a second portion in the sensing region and partially covering the sensing electrode pattern layer. A method of forming a touch sensor device is also disclosed.