Display Device Bridge Electrode Short-Circuit Prevention

Solution Overview

Problem

In display devices with integrated touch screens, the over-etching of bridge electrodes during the etching process can lead to short-circuiting of first and second touch electrodes, preventing normal touch sensing functionality.

Innovation Solution

The implementation of a display device design that includes a bridge electrode electrically connected to the first touch electrode and spaced apart from a dummy electrode, with both on the same layer, and an insulation layer covering them, along with the formation of contact holes to connect the touch electrodes to the bridge and dummy electrodes, respectively, to prevent short-circuiting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If bridge electrodes are spaced apart by a certain interval, then the etching process can be performed, but the bridge electrodes can be over-etched leading to short-circuiting of touch electrodes

Engineering Contradiction:

Improveetching processVSAvoidtouch sensing functionality

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

A protective film is formed on the bridge electrodes before the etching process to prevent over-etching. This preliminary protective action ensures that the bridge electrodes are not etched beyond their intended pattern, thereby preventing short-circuiting of the touch electrodes while still allowing the etching process to proceed for other structures.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The protective film acts as an intermediary layer between the etching process and the bridge electrodes. It selectively protects the bridge electrodes from the etchant while allowing the etching process to remove unwanted materials elsewhere in the structure, thus preventing direct contact between touch electrodes.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If insulation layer is provided on bridge electrodes, then electrical insulation is achieved, but openings in over-etching regions cause short-circuits between touch electrodes and bridge electrodes

Engineering Contradiction:

Improveelectrical insulationVSAvoidopening position accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The protective film is formed on the bridge electrodes before the etching process to prevent over-etching. This preliminary protective action ensures that the bridge electrodes are not etched beyond their intended pattern, thereby preventing short-circuiting of the touch electrodes while still allowing the etching process to proceed for other structures.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The protective film acts as an intermediary layer between the etching process and the bridge electrodes. It selectively protects the bridge electrodes from the etchant while allowing the etching process to remove unwanted materials elsewhere in the structure, thus preventing direct contact between touch electrodes.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If bridge electrodes are provided in multi-layer structure, then electrical connection is achieved, but Al layer is over-etched compared to Ti layers causing reverse taper shape

Engineering Contradiction:

Improveelectrical connectionVSAvoidelectrode shape control

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

A protective film is formed on the bridge electrodes before the etching process to prevent over-etching. This preliminary protective action ensures that the bridge electrodes are not etched beyond their intended pattern, thereby preventing short-circuiting of the touch electrodes while still allowing the etching process to proceed for other structures.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The protective film acts as an intermediary layer between the etching process and the bridge electrodes. It selectively protects the bridge electrodes from the etchant while allowing the etching process to remove unwanted materials elsewhere in the structure, thus preventing direct contact between touch electrodes.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11422652B2Display device with integrated touch screen

Publication Date: 2022.08.23 LG DISPLAY CO LTD

AI summary

Disclosed is a display device with integrated touch screen, which can prevent a first touch electrode or a second touch electrode from being short-circuited with a bridge electrode through an opening. The display device includes first electrodes on a first substrate, a light emitting layer on the first electrodes, a second electrode on the light emitting layer, an encapsulation layer on the second electrode, a bridge electrode and a dummy electrode on the encapsulation layer, an insulation layer covering the bridge electrode and the dummy electrode, and a first touch electrode and a second touch electrode on the insulation layer. The first touch electrode is electrically connected to the bridge electrode, and bridge electrode is spaced apart from the dummy electrode.