Thin Coupling Unit for Laser Repair of Display Dark Spots
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In display devices, the formation of dark spots due to foreign substances during the manufacturing process of light-emitting elements leads to brightness defects, and existing solutions that commonize electrode layers to reduce light exposure processes struggle to recover these defects effectively due to thickened wiring that is difficult to cut with laser emission.
Innovation Solution
A display device configuration where the coupling unit connecting the light-emitting element and the drive circuit includes a metal layer thinner than the thin film transistor's electrode layers, allowing for effective recovery of dark spots by laser cutting, and a manufacturing method involving the formation of a coupling unit with a first electrode layer on a transparent substrate, interlayer insulation, and patterning of a second electrode layer to facilitate over-etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If electrode layers are commonized to reduce light exposure processes, then manufacturing efficiency is improved, but wiring thickness increases making laser cutting difficult
Solution Approach 1:
The patent segments the coupling unit into multiple layers: a first electrode layer (thinner) and a second electrode layer (thicker). This segmentation allows the first layer to be laser-cuttable while the second layer provides sufficient conductivity, resolving the contradiction between manufacturability and ease of repair.
Solution Approach 2:
The patent applies local quality by making different portions of the coupling unit have different thicknesses. The first electrode layer has reduced thickness in specific regions to enable laser cutting, while the second electrode layer maintains greater thickness for electrical performance, allowing defect recovery without sacrificing manufacturing efficiency.
2Device complexity
If reflective electrode layer is thickened to serve multiple functions, then device complexity is reduced, but defect recovery capability deteriorates
Solution Approach 1:
The patent divides the reflective electrode layer into two separate layers: a first electrode layer optimized for laser cutting (thinner) and a second electrode layer optimized for reflectivity and conductivity (thicker). This segmentation enables both defect recovery and functional performance without requiring additional electrode layers.
Solution Approach 2:
The patent resolves the contradiction by transitioning from a single-layer structure to a multi-layer structure in the vertical dimension. This dimensional change allows each layer to be optimized for its specific function while maintaining overall device simplicity.
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 approach reduces the number of light-exposure processes, improves defect recovery by enabling laser cutting of the thinner coupling unit, and enhances image quality by reducing point defects like dark spots in display devices.
Implementation Method 1
it is possible to cut wiring with a laser emitted after the completion of a display panel
Data Source
AI summary
A display device of the present disclosure includes a plurality of pixels, in which a pixel includes a light-emitting element, a drive circuit which has a thin film transistor driving the light-emitting element, and a coupling unit which connects the light-emitting element and the drive circuit to each other, the light-emitting element has a configuration in which an organic layer including a light-emitting layer is interposed between a transparent electrode and a reflective electrode, the thin film transistor has a configuration which includes a semiconductor layer, an insulation layer, a first electrode layer, and a second electrode layer, and the coupling unit includes a metal layer which is thinner than the first electrode and the second electrode of the thin film transistor the metal layer being disposed in one portion of the coupling unit.