LCD Pixel Electrode Coupling for White Defect Repair
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Solution Overview
Problem
In IPS LCD panels, incomplete removal of the ohmic contact layer during manufacturing leads to doped ions remaining on the semiconductor layer, causing current leakage and voltage discrepancies, resulting in white defects due to improper grayscale display.
Innovation Solution
A method involving laser irradiation to separate the drain electrode into two parts, forming through holes in the insulation layers, and coupling the pixel electrode to the common electrode to maintain a zero voltage difference, thereby converting white defects to dark defects and preventing electrode oxidation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the drain electrode is separated into two parts using a laser to repair white defects, then the white defect is converted to a dark defect and voltage control is improved, but the separated electrode parts are exposed to air and oxidation which affects display quality
Solution Approach 1:
A protective film is introduced as an intermediary layer between the separated drain electrode parts and the air environment. This protective film prevents direct exposure to air, thereby avoiding oxidation of the electrode parts while maintaining the voltage control improvement achieved through electrode separation.
Solution Approach 2:
The protective film creates an inert environment around the separated electrode parts, isolating them from oxygen in the air. This inert barrier prevents oxidation reactions that would otherwise degrade the electrode performance and display quality.
2Reliability
If the drain electrode is separated into two parts using a laser, then current leakage is reduced and voltage stability is improved, but the gate insulation layer is damaged causing oxidation of the gate electrode which affects signal transmission
Solution Approach 1:
The protective film serves as a mediator that shields the gate insulation layer and gate electrode from oxidation during and after the laser separation process. This intermediary layer prevents direct contact between oxygen and the sensitive gate structures, maintaining signal transmission integrity.
Solution Approach 2:
The protective film is applied beforehand to cushion and protect the gate insulation layer and gate electrode from oxidation damage that would occur during the laser separation process. This preventive measure ensures the gate electrode remains intact and functional.
3Productivity
If the ohmic contact layer is not completely removed during manufacturing, then manufacturing efficiency is maintained, but doped ions remain on the semiconductor layer causing current leakage and white defects
Solution Approach 1:
The drain electrode is segmented into two separate parts through laser irradiation. This segmentation isolates the region with remaining ohmic contact layer material, confining the current leakage to a localized area that can be managed independently, thereby maintaining overall display functionality despite incomplete manufacturing removal.
Solution Approach 2:
The protective film, initially introduced to prevent oxidation, is converted into a beneficial element that also serves to encapsulate and isolate any remaining doped ions from the ohmic contact layer. This dual-function approach transforms a protective measure into a solution that addresses both oxidation prevention and current leakage mitigation.
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
The method effectively resolves white defects by maintaining proper voltage differences and preventing electrode oxidation, enhancing display quality by ensuring consistent grayscale display.
Implementation Method 1
A method involving laser irradiation to separate the drain electrode into two parts, forming through holes in the insulation layers
Data Source
AI summary
A method for repairing a white defect of a LCD panel includes providing a substrate defining a plurality of pixel areas by: forming a base, a first metal layer, a first insulation layer, a channel layer, a second metal layer, and a second insulation layer; forming a first conductive layer on the second insulation layer; forming a first through hole in the second insulation layer by laser, extending the first through hole through the second insulation layer and separating the drain electrode into two parts; covering a third insulation layer; forming a second conductive layer on the third insulation layer; penetrating the first conductive layer by laser to coupling the second conductive layer to the first conductive layer; and forming a second through hole in the third insulation layer.