Touch Panel Shielding Structure for Impedance Consistency
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Solution Overview
Problem
Conventional touch panels experience noise interference due to inconsistent impedance of the shielding layer, which weakens the noise absorption effect, especially when the distance between the shielding layer and the FPC varies.
Innovation Solution
A touch panel with a shielding structure that uses a wrap-around conductive ring electrically connected to the shielding layer through multiple conductive connection points, ensuring consistent impedance regardless of the distance between the shielding layer and the FPC, thereby eliminating noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a shielding layer is formed between the touch panel and the electronic device with one end electrically connected to a shielding pin of FPC, then noise absorption capability is provided, but impedance inconsistency occurs due to varying distances from different parts of the shielding layer to the shielding pin
Solution Approach 1:
A conductive ring is introduced as an intermediary element between the shielding layer and the shielding pin. The conductive ring is electrically connected to the shielding layer through multiple connection points and to the shielding pin through a single connection point. This intermediary structure equalizes the impedance across different distances by providing multiple parallel conduction paths, thereby resolving the impedance inconsistency while maintaining noise absorption capability.
Solution Approach 2:
The shielding layer is segmented into multiple sections through multiple conductive connection points distributed around its periphery. Each connection point creates a separate electrical path to the conductive ring, effectively dividing the impedance problem into multiple smaller, equalized segments. This segmentation approach ensures that no single long path dominates the impedance characteristics.
2Area of stationary object
If the shielding layer is connected to the shielding pin through a long distance, then noise absorption coverage is increased, but impedance increases and noise shielding effect is weakened
Solution Approach 1:
The connection structure transitions from a one-dimensional linear connection (single path from shielding layer to shielding pin) to a two-dimensional distributed connection (multiple paths through connection points around the periphery). The conductive ring provides a spatial distribution of connection points that reduces the effective path length in each direction, thereby lowering overall impedance while maintaining comprehensive shielding coverage.
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 eliminates noise interference from electronic devices by maintaining consistent impedance, improving the noise absorption capability of the touch panel, and simplifies the manufacturing process, reducing costs.
Implementation Method 1
a plurality of conductive connection points electrically connecting the shielding layer and the conductive ring
Implementation Method 2
impedance of the shielding layer is consistent even if the distance between the shielding layer and the shielding pin is different
Data Source
AI summary
The present disclosure relates to a touch panel having a shielding structure and a method of manufacturing the same. The touch panel having a shielding structure comprises a conductive ring disposed on periphery of an upper surface of a substrate, a shielding layer disposed on a lower surface of the substrate, and a plurality of conductive connection points electrically connecting the shielding layer and the conductive ring. By connecting the shielding layer and the conductive ring by the conductive connection points, impedance of the shielding layer is consistent for different distances between the shielding layer and flexible printed circuit, thereby eliminating noise interference from a liquid crystal display or an electronic device under the touch panel, while using the touch panel. Moreover, the manufacturing method of the touch panel with a shielding structure is a simple process, which reduces the manufacturing cost.