Display Device Slit and Island Protrusion for Wiring Stress Relief

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Solution Overview

Problem

In organic EL display devices, the lead-out wiring line is prone to breakage or peeling due to stress concentration at specific portions, especially in the bending portions where the wiring line is pulled to both sides.

Innovation Solution

The display device incorporates a slit in the bending portion with step portions and island-shaped protruding portions, where the lead-out wiring line is electrically connected and includes an opening covering the perimeter edge surfaces of the protruding portions, enhancing adhesion and reducing stress concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the lead-out wiring line is drawn through multiple steps in the bending portion, then the wiring line can connect different regions, but stress concentration occurs at step portions causing breakage or peeling

Engineering Contradiction:

Improvewiring line connectivityVSAvoidwiring line integrity

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The slit is divided into a first slit in the first inorganic insulating film and a second slit in the second inorganic insulating film with different widths, creating segmented step portions that reduce stress concentration on the wiring line while maintaining connectivity across the bending portion

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Island-shaped protruding portions are provided at specific locations within the slits where the wiring line passes through step portions. These protruding portions locally enhance adhesion and distribute stress, preventing breakage or peeling at critical stress concentration points while maintaining overall wiring line connectivity

Inventive Principle:

Principle #3Local quality

2Area of stationary object

If the frame region is bent to reduce area, then the display device achieves flexibility and compact form factor, but bending stress causes inorganic insulating layer removal and wiring line damage

Engineering Contradiction:

Improveframe region areaVSAvoidbending portion durability

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The inorganic insulating film structure is segmented into multiple layers with slits at different levels, creating step portions that reduce bending stress concentration and prevent complete layer removal while maintaining the compact bent form factor

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Island-shaped protruding portions are strategically placed at stress concentration points within the slits to locally reinforce the structure, preventing inorganic insulating layer removal and wiring line damage in the bent frame region

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12310201B2Display device with slits and island-shaped protruding portions in the bending regions

Publication Date: 2025.05.20 SHARP KK

AI summary

A display device includes a resin substrate and a thin film transistor layer. The thin film transistor layer includes a first inorganic insulating film, a second inorganic insulating film, and a lead-out wiring line. A frame region includes a bending portion provided with a slit constituted with a first slit and a second slit. Portions of the first inorganic insulating film on both sides in a width direction of the first slit constituting step portions are exposed from the second inorganic insulating film inside the second slit. The lead-out wiring line is electrically connected to the thin film transistor. The step portions are provided with a protruding portion having an island shape. The lead-out wiring line includes an opening covering perimeter edge surface of the protruding portion and exposing an upper face of the protruding portion.