Touch Panel Electrode Stacking for Uniform Protective Film
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Solution Overview
Problem
Conventional capacitance coupling type touch panels suffer from electrode pattern visibility due to color differences caused by distortion in the protective film, leading to deterioration of optical characteristics and reduced display device performance.
Innovation Solution
The touch panel design features electrodes formed on different conductive layers with a contact hole through an insulating film, allowing for uniform protective film formation and minimizing electrode pattern visibility by using transparent conductive materials like indium tin oxides, with alternating wider and narrower portions to ensure electrical and mechanical connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrodes are formed on different conductive layers via an insulating film, then capacitance coupling function is achieved, but protective film distortion occurs and electrode patterns become visible
Solution Approach 1:
The patent transitions from a planar electrode arrangement to a three-dimensional stacked configuration with electrodes on different conductive layers. This dimensional change enables capacitance coupling while allowing the protective film to be formed uniformly over the entire surface, preventing pattern visibility issues that occur in planar designs.
Solution Approach 2:
The patent introduces an insulating film as an intermediary layer between electrodes on different conductive layers. This intermediary enables electrical isolation while maintaining mechanical continuity, allowing the protective film to be deposited uniformly without following the contours of underlying electrodes, thus preventing distortion and pattern visibility.
2Illumination intensity
If transparent conductive materials are used for electrodes, then optical characteristics are improved, but color differences still occur due to protective film distortion
Solution Approach 1:
By stacking electrodes on different conductive layers rather than arranging them in the same plane, the patent eliminates the root cause of protective film distortion. This allows transparent conductive materials to maintain their optical properties without inducing color differences through film thickness variations.
Solution Approach 2:
The patent achieves homogeneous protective film thickness across the entire surface by forming the film after the stacked electrode structure is complete. This uniform deposition prevents the color differences that arise when protective film thickness varies over distorted surfaces, while still using transparent conductive materials for optimal optical characteristics.
Data Source
AI summary
A manufacturing method of a touch panel includes the steps of providing a substrate, forming a first conductive film on the substrate, forming a first mask on the first conductive film, etching the first conductive film to form electrode portions and lower intersect portions of the touch panel, forming an insulating film made of a negative resist on the first conductive film, and forming a contact hole above the electrode portion by removing the insulating film. The steps further include forming a second conductive film on the insulating film, forming a second mask on the second conductive film, etching the second conductive film to form an upper intersect portion connected between two adjacent electrode portions via the contact hole and intersecting with the lower intersect portion, and forming protective film on the second conductive film.