Touch Panel Split Wiring for Partial Disconnection Detection

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Solution Overview

Problem

Existing touch panel inspection methods fail to detect partial disconnections in lead-out wiring lines, which can progress to complete disconnections, leading to undetected defects in the inspection process.

Innovation Solution

A continuity inspection method using a probe to contact split terminals and split wiring lines, allowing for detection of partial disconnections that may change to complete disconnections, with the lead-out wiring line being divided into independent split lines and external connection terminals also divided by a slit, ensuring accurate defect detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single lead-out wiring line connects sensor electrodes to external terminals, then the structure is simple and manufacturing is easy, but partial disconnections cannot be detected during inspection

Engineering Contradiction:
Improvedefect detection accuracyVSAvoidwiring line structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The lead-out wiring line is divided into multiple independent wiring lines (first lead-out wiring line and second lead-out wiring line). This segmentation allows the inspection system to detect partial disconnections by testing continuity through each separate path, resolving the contradiction between detection accuracy and structural simplicity.

Inventive Principle:
Principle #1Segmentation

2Reliability

If continuity inspection is performed on traditional single wiring lines, then inspection process is simple, but progressive defects (partial disconnections) are not detected

Engineering Contradiction:
Improveproduct qualityVSAvoidinspection complexity
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent implements continuity inspection before shipping to detect partial disconnections in advance. By performing this preliminary detection action, progressive defects are identified before they can progress to complete failures during subsequent stress tests or usage, thereby improving product reliability.

Inventive Principle:
Principle #10Preliminary action

3Area of stationary object

If lead-out wiring lines are made narrower to reduce formation width, then space efficiency improves, but the wiring lines become more susceptible to disconnection

Engineering Contradiction:
Improveformation widthVSAvoidwiring line stability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

By dividing the wiring function into multiple narrower lines rather than using fewer wider lines, the patent maintains space efficiency while improving reliability. The segmented structure allows redundant paths for electrical connection, so if one narrow line disconnects, others can still maintain functionality.

Inventive Principle:
Principle #1Segmentation

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

Enables easy detection of defects in touch panels with a high likelihood of partial disconnection progressing to complete disconnection, ensuring accurate identification of defective products and maintaining touch panel functionality.

Implementation Method 1

a probe of a continuity inspection device is brought into contact with each of a pair of split terminals including the external connection terminal divided, and continuity between the split terminals via a pair of split wiring lines including the lead-out wiring line divided, and via the sensor electrode is inspected

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3901745B1Touch panel, touch panel module, and method for inspecting touch panel
Publication Date: 2023.05.03 NISSHA PRINTING CO LTD
  • EP3901745B1 patent drawingFigure 1~2
  • EP3901745B1 patent drawingFigure 3~4
  • EP3901745B1 patent drawingFigure 5~6

AI summary

Problem To provide a touch panel, a touch panel module, and a method for inspecting a touch panel that enable easy detection in inspection of a touch panel of a defect of a lead-out wiring line having a possibility that partial disconnection change to complete disconnection in the step subsequent to inspection. Solution means A touch panel (4) includes a substrate (8) having insulating properties and including a sensing region (S) and a non-sensing region (P), a plurality of sensor electrodes (1) formed in the sensing region (S), a plurality of external connection terminals (3) formed in the non-sensing region (P), and a lead-out wiring line (2) electrically connecting one end of each of the plurality of sensor electrodes (1) to each of the plurality of external connection terminals (3). The external connection terminal (3) and the lead-out wiring line (2) are continuously divided by a single slit (20, 30) along an extension direction of the external connection terminal and the lead-out wiring line in an entire length or in a portion of the entire length from which an end portion in a side of the sensor electrode of the lead-out wiring line is excluded.