OLED Touchscreen Pad Layout for Same-Side Stable Bonding

Solution Overview

Problem

The manufacturing process of organic light-emitting display devices with integrated touchscreens is complicated due to the separate attachment of touchscreens, leading to misalignment issues and increased processing burden and costs.

Innovation Solution

The touchscreen pads and circuit board are integrated on the same side of the substrate through a common formation process, ensuring alignment stability and simplifying the connection by preventing height differences between pads and the circuit board.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the touchscreen is separately manufactured and attached to the front surface of the display panel, then the touchscreen can be independently produced, but the manufacturing process becomes complicated and misalignment occurs

Engineering Contradiction:

Improveindependent production capabilityVSAvoidmanufacturing process complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the touchscreen and display panel manufacturing into a single integrated process. The touchscreen pads are formed on the same substrate as the display panel pads during the same manufacturing steps, eliminating the need for separate touchscreen production and attachment. This combines two previously separate manufacturing processes into one unified process.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The touchscreen pads are formed in advance during the display panel manufacturing process, before the display panel is completed. By preliminarily forming the touchscreen pads alongside the display pads using the same conductive material layers and patterning steps, the touchscreen structure is prepared simultaneously with the display structure, avoiding later attachment operations.

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If the touchscreen is separately manufactured and attached to the front surface of the display panel, then the touchscreen can be independently produced, but yield deteriorates due to misalignment

Engineering Contradiction:

Improveindependent production capabilityVSAvoidalignment precision

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent merges the touchscreen and display panel manufacturing into a single integrated process. The touchscreen pads are formed on the same substrate as the display panel pads during the same manufacturing steps, eliminating the need for separate touchscreen production and attachment. This combines two previously separate manufacturing processes into one unified process.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent creates equipotential conditions by using the same conductive material layers and formation processes for both display pads and touchscreen pads. Both sets of pads are formed from the same ITO layer through the same patterning steps, ensuring they are at the same manufacturing stage and eliminating relative positioning errors that would occur with separate manufacturing.

Inventive Principle:

Principle #12Equipotentiality

3Adaptability or versatility

If the touchscreen is separately manufactured and attached to the front surface of the display panel, then the touchscreen can be independently produced, but processing burden and costs increase

Engineering Contradiction:

Improveindependent production capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent merges the touchscreen and display panel manufacturing into a single integrated process. The touchscreen pads are formed on the same substrate as the display panel pads during the same manufacturing steps, eliminating the need for separate touchscreen production and attachment. This combines two previously separate manufacturing processes into one unified process.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent makes the manufacturing process universal by using the same materials, equipment, and process steps to create both display pads and touchscreen pads. The ITO layer serves dual purposes as both the display electrode material and the touchscreen electrode material, and the same sputtering and patterning equipment is used for both functions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP4224292B1Organic light-emitting display device having touchscreen and method of manufacturing the same

Publication Date: 2025.11.05 LG DISPLAY CO LTD

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AI summary

Disclosed are an organic light-emitting display device having a touchscreen in which the configuration of a pad unit and a circuit board connected to the pad unit is simplified, resulting in bonding stability and an improved form factor of the device, and a method of manufacturing the same. In the organic light-emitting display device having the touchscreen in which a touch electrode is directly provided on an encapsulation layer, a touch pad and a display pad are disposed parallel to each other on the same side so as to be connected to a flexible printed circuit board without a difference in height therebetween. Thereby, increased bonding reliability and an increased effective display area are achieved.