Touch Screen Metal Trace Adhesion and Frame Width Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing touch screen manufacturing methods face challenges in achieving a narrow frame width and flexible edge due to insufficient adhesion of metal traces on glass or polymer substrates, and misalignment issues during layered etching affect the line width limit of metal layers.
Innovation Solution
A method involving the formation of a first transparent conductive layer and a metal layer on a substrate, with specific photoresist patterns used for etching to create metal traces and transparent conductive patterns, followed by a protective layer and additional transparent conductive patterns, which improves adhesion and reduces misalignment effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If metal traces are formed from flexible metal materials to enable three-dimensional touch control and flexible edges, then the flexibility and edge flexibility are improved, but the adhesion on glass or polymer substrates is insufficient
Solution Approach 1:
The patent uses a composite structure consisting of a metal layer (flexible material) combined with a transparent conductive layer (adhesive material). This composite approach allows the metal traces to maintain flexibility for three-dimensional touch control while the transparent conductive layer provides strong adhesion to the glass or polymer substrate, resolving the contradiction between flexibility and adhesion.
2Ease of manufacture
If layered etching is performed on a composite film layer formed of metal material and other layers, then the metal trace pattern is formed, but misalignment greatly affects the line width limit of the metal layer
Solution Approach 1:
The patent applies for alignment marks before forming the metal layer, and uses these marks to guide the subsequent etching processes. By preparing the alignment reference in advance, the patent ensures that the etching of the metal layer and other layers can be precisely aligned, thereby maintaining the line width limit of the metal layer while enabling layered etching for pattern formation.
3Ease of operation
If the frame width is reduced to facilitate hand-holding, then the ease of operation is improved, but the line spacing of touch traces at the periphery becomes less than 10 μm which affects manufacturing precision
Solution Approach 1:
The patent divides the touch trace structure into separate functional layers: a metal layer for flexibility and a transparent conductive layer for adhesion and electrical conductivity. This segmentation allows the touch traces in the narrow frame area to be formed with precise line spacing through controlled etching of each layer independently, enabling the frame width to be reduced below 10 μm while maintaining manufacturing precision.
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 method enhances the adhesion and stability of metal layers, increases the line width limit, and reduces the frame width, resulting in a higher screen occupation ratio and improved performance and lifespan of the touch screen.
Implementation Method 1
performing an etching process by using the first photoresist pattern to form the metal trace
Implementation Method 2
forming a first transparent conductive layer on a side of the substrate, and forming a metal layer on a surface of the first transparent conductive layer
Data Source
AI summary
A method for manufacturing a touch screen which includes: providing a substrate including a display area and a non-display area located around the display area; forming a first transparent conductive layer on a side of the substrate, and forming a metal layer on a surface of the first transparent conductive layer facing away from the substrate; forming a first photoresist pattern on the metal layer, at least a portion of the first photoresist pattern corresponding to a metal trace to be formed in the non-display area; performing an etching process by using the first photoresist pattern to form the metal trace; forming a second photoresist pattern only in one of the display area and the non-display area, and performing an etching process to form a first transparent conductive pattern in the display area.