Metal Touch Electrodes in Color Filter Substrates

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Solution Overview

Problem

Capacitive embedded touch screens with indium tin oxide (ITO) touch electrodes face issues of high impedance, large thickness, and high cost due to ITO's properties.

Innovation Solution

A color filter substrate with metal or ashed metal touch electrodes, where the first touch electrode is positioned on the side of the color filter layer and the second touch electrode is on a different side of the transparent substrate, reducing impedance and thickness while lowering costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ITO is used to form touch electrodes, then the touch screen can be manufactured with conventional processes, but the impedance is high and cost is high

Engineering Contradiction:

Improvetouch screen performanceVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive ITO materials with cheaper metal materials (such as aluminum, copper, or their alloys) that can be processed through conventional semiconductor manufacturing processes. This substitution directly addresses the high cost issue while maintaining touch screen functionality through the use of patterned metal electrodes.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the material parameters from ITO (indium tin oxide) to metal materials, fundamentally altering the electrical and optical properties of the touch electrode layer. This parameter change enables lower impedance and reduced material cost while maintaining the touch screen's operational requirements.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If ITO is used to form touch electrodes, then the touch screen can be manufactured, but the thickness is large

Engineering Contradiction:

Improvetouch screen functionalityVSAvoidtouch screen thickness

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

The patent employs thin metal film layers deposited through conventional semiconductor processes to form touch electrodes. These thin metal films replace the thicker ITO layers, directly reducing the overall touch screen thickness while maintaining electrical conductivity and touch functionality.

Inventive Principle:

Principle #30Flexible shells and thin films

3Reliability

If ITO is used to form touch electrodes, then the touch screen can be manufactured, but the impedance is high

Engineering Contradiction:

Improvetouch screen operationVSAvoidimpedance level

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent fundamentally changes the electrical parameters by substituting ITO with metal materials that have inherently lower electrical resistance. This material substitution directly reduces the impedance of the touch electrode, improving touch sensitivity and signal quality while enabling conventional manufacturing processes.

Inventive Principle:

Principle #35Parameter changes

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 use of metal or ashed metal touch electrodes in the color filter substrate decreases impedance, reduces the size and cost of the touch screen, and improves touch sensitivity and display performance by avoiding Moire interference and reducing reflectivity.

Implementation Method 1

When a finger touches the capacitive embedded touch screen, a coupling capacitor is formed between the user and the surface of the capacitive embedded touch screen due to human electric field

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

the first touch electrode being made of metal or ashed metal... The current flows out through the touch electrodes

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 3

The color filter layer may include color pixels and a black matrix between the adjacent color pixels

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS9990068B2Color filter substrate, fabricating method of color filter substrate, touch screen and display device

Publication Date: 2018.06.05 BOE TECHNOLOGY GROUP CO LTD

AI summary

The invention discloses a color filter substrate, a method for fabricating the color filter substrate, a touch screen and a display device. The color filter substrate comprises: a transparent substrate; a color filter layer provided on one side of the transparent substrate; a first touch electrode provided on the side of the transparent substrate where the color filter layer is located, the first touch electrode being made of metal or ashed metal; and a second touch electrode provided on one side of the transparent substrate. The embodiments of the invention solve the problems that a touch screen with touch electrodes made of ITO has high impedance, large thickness and high cost, thus lowering the impedance of the touch screen, reducing the thickness of the touch screen and lowering the cost.