Touch Panel Metal Trace Fabrication via Composite Oxide Layer

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Solution Overview

Problem

The challenge in fabricating touch panels is the difficulty in achieving efficient etching of metal traces with pure copper or aluminum, which leads to issues like insufficient adhesion and oxidation, while also increasing process costs and complexity due to the need for multilayer structures.

Innovation Solution

A fabrication method that forms a first conductive layer on a base substrate, followed by a single layer of metal traces with connection ends, and then an insulating layer, allowing for simultaneous formation of touch electrodes and conductive traces in separate regions, thereby improving etching efficiency and reducing process costs by eliminating the need for multilayer structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pure copper or aluminum is used for metal traces to improve conductivity, then electron mobility and touch sensing sensitivity are improved, but etching difficulty increases leading to insufficient adhesion and oxidation problems

Engineering Contradiction:
Improveconductivity and touch sensing sensitivityVSAvoidetching efficiency and adhesion
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies composite material structure by combining pure copper or aluminum metal traces with a protective oxide layer and insulating layers. The metal trace layer (300) is formed with high-purity copper or aluminum for optimal conductivity, then a controlled oxide layer is formed on its surface to prevent further oxidation and improve adhesion. This composite approach maintains the electrical benefits of pure metals while eliminating their manufacturing drawbacks.

Inventive Principle:
Principle #40Composite materials

2Reliability

If multilayer metal structures are used to prevent oxidation and improve adhesion, then manufacturing reliability is improved, but process complexity and costs increase

Engineering Contradiction:
Improveoxidation resistance and adhesionVSAvoidnumber of layers and processes
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the essential protective function from complex multilayer metal structures and implements it through a simplified approach: forming a single metal trace layer of pure copper or aluminum, then applying a controlled oxide layer only where needed for adhesion and protection. This eliminates the need for multiple metal buffer layers while achieving the same protective effect, thereby reducing process complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the oxidation parameter from uncontrolled (which causes manufacturing defects) to controlled (forming a thin, uniform oxide layer that provides protection). By controlling the oxidation process to create a specific oxide thickness and uniformity, the patent transforms oxidation from a harmful effect into a beneficial protective mechanism, eliminating the need for additional protective layers.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If multiple patterning processes are used to form conductive layers and traces separately, then manufacturing precision is improved, but production time and costs increase

Engineering Contradiction:
Improvetrace formation accuracyVSAvoidetching time and process efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent merges the formation of conductive layers and metal traces into a single integrated process. The metal trace layer is formed directly over the conductive layer in one etching step, with both structures defined by the same patterning process. This consolidation maintains manufacturing precision while significantly reducing the number of separate processes and overall production time compared to forming each layer separately.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3640774B1Panel manufacturing method, panel and display device
Publication Date: 2023.08.30 BOE TECHNOLOGY GROUP CO LTD
  • EP3640774B1 patent drawingFigure 1~2B
  • EP3640774B1 patent drawingFigure 3A~3B
  • EP3640774B1 patent drawingFigure 4A~4C

AI summary

A fabrication method of a panel, a panel and a display device are provided. The fabrication method of the panel includes: forming a first conductive layer on a base substrate (100) by using a patterning process, the first conductive layer including a plurality of first conductive traces (210) provided in a non-working region of the base substrate (100) and a plurality of electrode patterns provided in a working region of the base substrate(100); forming a plurality of metal traces (300) on the plurality of first conductive traces (210), wherein, each of the metal traces (300) includes a connection end (315) close to an edge of the working region of the base substrate (100).