Touch Panel Bezel Wiring With Barrier Layer for Stable Signals

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Solution Overview

Problem

Existing touch panel fabrication methods often result in electrode wires with increased line resistance or open-circuits due to surface defects in the light blocking layer, leading to decreased touch sensitivity and operation speed.

Innovation Solution

A method for forming high-quality electrode wires by depositing a transparent conductor and conductive metal on a printed light blocking layer, with a barrier layer formed to prevent etching defects, ensuring stable signal transmission despite surface defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a light blocking layer is fabricated using the BM scheme with pigment, then the color and design diversity is improved, but the surface becomes rough and vulnerable to foreign materials or bumps

Engineering Contradiction:
Improvecolor diversityVSAvoidsurface flatness
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent divides the light blocking layer into multiple segments: a base light blocking layer providing color diversity through pigment, and multiple compensation layers (first compensation layer, second compensation layer) that separately address surface flatness. This segmentation allows each layer to perform its specific function without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first compensation layer acts as an intermediary between the pigmented light blocking layer and the second compensation layer. It provides initial surface planarization and serves as a foundation for the second compensation layer, which further refines the surface flatness. This intermediary approach enables gradual correction of surface defects.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the light blocking layer surface is rough with foreign materials or bumps, then color diversity is achieved, but electrode wire quality deteriorates with increased line resistance or open-circuits

Engineering Contradiction:
Improvedesign diversityVSAvoidelectrode wire quality
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies preliminary action by forming the first and second compensation layers before depositing the transparent conductor and conductive metal for electrode wires. These compensation layers pre-planarize the surface, ensuring a smooth foundation for subsequent electrode wire formation, thereby preventing line resistance increase and open-circuits.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The compensation layers serve as a cushioning mechanism that absorbs and compensates for surface defects in the pigmented light blocking layer. By providing this protective cushioning layer beforehand, the patent prevents foreign materials and bumps from directly affecting electrode wire quality and signal transmission.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Ease of manufacture

If electrode wires are formed directly on the light blocking layer, then the fabrication process is simplified, but touch sensitivity and operation speed decrease due to increased line resistance

Engineering Contradiction:
Improvefabrication simplicityVSAvoidtouch sensitivity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies local quality by making the compensation layers specifically in the bezel area where the light blocking layer is located, rather than across the entire substrate. This localized approach maintains fabrication simplicity while improving electrode wire quality only where needed, without adding unnecessary complexity to other areas.

Inventive Principle:
Principle #3Local quality

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 approach ensures good quality wiring electrodes, allowing for reduced line width and interval, resulting in a narrower bezel and improved touch panel performance with enhanced sensitivity and speed.

Implementation Method 1

depositing a transparent conductor and conductive metal on a printed light blocking layer

Methodology Applied
Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Implementation Method 2

a barrier layer formed to prevent etching defects

Methodology Applied
Scientific EffectPhysical barrier protection:

Data Source

PatentEP3080685B1Method for fabricating touch panel, touch panel, and electronic device having the touch panel
Publication Date: 2022.12.21 SAMSUNG ELECTRONICS CO LTD
  • EP3080685B1 patent drawingFigure 1~2
  • EP3080685B1 patent drawingFigure 3~4
  • EP3080685B1 patent drawingFigure 5~6

AI summary

A method for fabricating a touch panel, a touch panel, and an electronic device having the touch panel are provided. The touch panel includes a window member including a view area and a bezel area surrounding the view area, a sensor layer formed in the view area on a surface of the window member and including a sensor pattern for detecting a user input, a light blocking layer formed in the bezel area on the surface of the window member, a wiring layer formed on a surface of the light blocking layer and connected to the sensor pattern, and a barrier layer formed on the surface of the light blocking layer or a surface of the wiring layer.