Foldable Display Wiring Layout to Prevent Bending Short-Circuits

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Solution Overview

Problem

Existing display apparatuses face challenges in achieving increased durability and reducing manufacturing costs while minimizing defects such as short-circuits during the bending process, which affects the flexibility and reliability of the display.

Innovation Solution

The display apparatus incorporates a substrate with a bending area, an encapsulation layer, a touch electrode, and fan-out wiring made of the same material, which extends into the bending area, along with an organic material layer to absorb tensile stress and prevent fractures, thereby enhancing durability and reducing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the display apparatus is bent to enhance visibility and reduce non-display area size, then adaptability and compactness are improved, but the risk of short-circuits and fractures increases

Engineering Contradiction:
Improvebending capabilityVSAvoiddefect occurrence
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The non-display area is divided into a bending area and a non-bending area, with different wiring configurations in each zone. The bending area uses fan-out wiring with larger bending radii and different material compositions to accommodate deformation, while the non-bending area maintains standard wiring structures, thus enabling bending capability while preventing defects in critical regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different wiring structures and materials are applied to different regions of the display apparatus. The fan-out wiring in the bending area uses materials with higher flexibility and larger routing radii compared to the standard wiring in the non-bending area, allowing the device to bend without causing short-circuits or fractures in the most susceptible regions.

Inventive Principle:
Principle #3Local quality

2Reliability

If different materials are used for fan-out wiring and touch wiring, then electrical performance is optimized, but manufacturing complexity and costs increase

Engineering Contradiction:
Improveelectrical performanceVSAvoidmanufacturing process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The fan-out wiring and touch wiring are merged into a single wiring layer using the same conductive material. This integration simplifies the manufacturing process by reducing the number of deposition steps and material transitions, while still allowing for optimized routing paths in the bending area to maintain electrical performance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

A single wiring layer performs multiple functions: it serves as both the fan-out wiring for signal transmission and the touch wiring for touch sensing. This multi-functional design eliminates the need for separate material layers, simplifying manufacturing while maintaining the electrical performance required for both display control and touch interaction.

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

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

This design enhances the durability of the display apparatus by reducing the occurrence of short-circuits and fractures during bending, while also simplifying the manufacturing process and lowering costs by minimizing defects.

Implementation Method 1

an organic material layer which surrounds the fan-out wiring in the bending area

Methodology Applied
Scientific EffectTensile stress absorption: Elasticity

Data Source

PatentEP3792736B1Display apparatus and method of manufacturing the same
Publication Date: 2023.12.13 SAMSUNG DISPLAY CO LTD
  • EP3792736B1 patent drawingFigure 1
  • EP3792736B1 patent drawingFigure 2A
  • EP3792736B1 patent drawingFigure 2B

AI summary

A display apparatus including a substrate having a display area in which a display device is provided to display an image, and a non-display area around the display area. The non-display area includes a bending area that is bent about a bending axis; an encapsulation layer arranged above the display area; a touch electrode arranged above the encapsulation layer; a touch wire connected to the touch electrode and extending to the non-display area; and a fan-out wiring connected to a signal wiring that applies electric signals to the display area. At least a portion of the fan-out wiring is arranged in the bending area, and the fan-out wiring includes the same material as the touch wire.