LCD Touch Screen Common Electrode Mask Merging

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing manufacturing processes for liquid crystal display devices with built-in touch screens are complex, leading to increased costs and reduced efficiency due to the use of multiple masks and processes, which affects the contact efficiency between data and pixel electrodes, and results in higher production costs and lower yield.

Innovation Solution

The use of low-temperature poly silicon (LTPS) for the lower substrate and a simplified manufacturing process that reduces the number of masks required, specifically employing a half-tone mask to form the common electrode and conductive line simultaneously, enhancing contact efficiency and reducing manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple masks and complex manufacturing processes are used to form common electrode and conductive lines separately, then manufacturing precision can be maintained, but device complexity and manufacturing cost increase significantly

Engineering Contradiction:
Improvecontact efficiency between data and pixel electrodesVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges the formation of common electrode and conductive lines into a single mask process. The mask pattern is designed to simultaneously define both the common electrode regions and conductive line regions, eliminating the need for separate masking steps and reducing overall process complexity while maintaining manufacturing precision

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The mask serves multiple functions by simultaneously defining both common electrode patterns and conductive line patterns in a single application. This multi-functional mask approach reduces the total number of masking operations required and simplifies the manufacturing workflow

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If multiple separate processes are used to form common electrode and conductive lines, then manufacturing precision is maintained, but productivity decreases due to increased processing time

Engineering Contradiction:
Improvealignment accuracyVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent combines multiple formation processes into a single integrated step where both common electrode and conductive lines are formed simultaneously using one mask application and one development process, significantly reducing total processing time while maintaining alignment accuracy through the unified pattern definition

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The mask is designed in advance to contain all necessary pattern information for both common electrode and conductive lines, allowing both structures to be formed in a single operation without requiring sequential processing steps that would increase manufacturing time

Inventive Principle:
Principle #10Preliminary action

3Reliability

If conventional manufacturing processes are used with multiple masks, then process control is maintained, but manufacturing cost increases due to additional materials and steps

Engineering Contradiction:
Improveprocess controlVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent consolidates multiple mask materials and processing steps into a single mask system, reducing material consumption and eliminating redundant process steps while maintaining reliable process control through the integrated design that defines all necessary structures in one operation

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2431847B1Liquid crystal display device with a built-in touch screen and method for manufacturing the same
Publication Date: 2016.11.02 LG DISPLAY CO LTD
  • EP2431847B1 patent drawingFigure 1~2
  • EP2431847B1 patent drawingFigure 3~4
  • EP2431847B1 patent drawingFigure 5

AI summary

A liquid crystal display device with a built-in touch screen comprising a substrate having a pixel region, a thin film transistor formed at the pixel region, the thin film transistor including at least an active layer, a gate electrode, an insulating layer, and a data electrode, a first passivation layer formed on the thin film transistor, a first contact hole formed through a portion of the first passivation layer to expose the data electrode, a common electrode formed on at least one portion of the first passivation layer including inside the first contact hole, the common electrode operable to sense touch, a conductive line formed on at least one portion of the first passivation layer including inside the first contact hole, a second passivation layer formed on the common electrode and the conductive line, a second contact hole formed through a portion of the second passivation layer to expose the conductive line corresponding to the data electrode, and a pixel electrode electrically connected with the conductive line, the pixel electrode formed on the second passivation layer and inside the second contact hole, wherein the data electrode and the pixel electrode are electrically connected via the common electrode and the conductive line.