Pixel Repair Layer Structure for Laser-Isolated Display Defects
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Solution Overview
Problem
Existing display devices face issues with malfunctioning pixels that appear as bright or dark spots, and current repair methods often damage surrounding components due to improper laser cutting techniques, particularly affecting the conductive and insulating layers.
Innovation Solution
A display device structure is designed with a repair pattern overlapping the active layer, allowing for precise laser cutting of the active layer to isolate malfunctioning pixels without damaging the conductive layer or lower polarizer, using a laser beam that propagates through the repair pattern but not the surrounding layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of repair
If a laser beam is used to cut the conductive layer for pixel repair, then the malfunctioning pixel can be isolated, but the laser beam may propagate and damage the lower polarizer and other surrounding components
Solution Approach 1:
The patent introduces an intermediate layer structure consisting of a buffer layer and an active layer positioned between the repair pattern and the conductive layer. This intermediate structure acts as a mediator that stops the laser beam before it reaches the lower polarizer, preventing damage to surrounding components while still enabling effective cutting of the repair pattern for pixel isolation.
Solution Approach 2:
The patent changes the vertical stacking order of layers, placing the buffer layer and active layer in between the repair pattern and the conductive layer. This dimensional rearrangement creates a new layer configuration where the laser beam is absorbed or blocked by the active layer before reaching deeper layers, thus protecting the lower polarizer from laser damage.
2Manufacturing precision
If the repair pattern is stacked under the active layer, then laser cutting can be performed more precisely, but the crack may propagate to the active layer and cause it to be cut
Solution Approach 1:
The patent positions the buffer layer between the repair pattern and the active layer to serve as a cushioning layer. This buffer layer absorbs or mitigates the crack propagation energy generated during laser cutting of the repair pattern, preventing cracks from reaching and damaging the active layer, thus maintaining active layer integrity while enabling precise laser cutting.
3Ease of repair
If the active layer is cut to separate the malfunctioning pixel, then the pixel can be isolated from the light emitting element, but the conductive layer and insulating layers may be damaged by the laser
Solution Approach 1:
The buffer layer and active layer configuration acts as an intermediary structure that enables selective laser cutting. The laser beam is designed to cut through the repair pattern and buffer layer while being stopped by the active layer, preventing further propagation to the conductive and insulating layers below, thus isolating the malfunctioning pixel without damaging other critical layers.
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 method effectively repairs malfunctioning pixels by isolating them from the light-emitting element, preventing damage to the conductive and insulating layers, and avoiding damage to the lower polarizer, thus maintaining display quality.
Implementation Method 1
when the repair pattern is cut by a laser beam emitted from the outside
Implementation Method 2
using a laser beam that propagates through the repair pattern but not the surrounding layers
Data Source
AI summary
A display device includes: a substrate on which circuit elements constituting a pixel are arranged; a repair pattern arranged overlying the substrate; a buffer layer covering the repair pattern; an active layer arranged overlying the buffer layer; a conductive layer which is arranged overlying the active layer and on which electrodes of the circuit elements are arranged; an overcoat layer covering the conductive layer, and a light emitting element arranged overlying the overcoat layer. The repair pattern is arranged in such a manner that one region thereof overlaps the active layer.