PSA Curing Line Peeling Prevention in Display Substrates
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Solution Overview
Problem
Conventional curing lines in polymer-stabilized alignment (PSA) LCD fabrication processes are prone to peeling due to the doping process, leading to incomplete curing and alignment of the liquid crystal layer, which affects the yield rate and quality of the display panels.
Innovation Solution
The design of an active device array mother substrate with curing lines formed in the same layer as the source and drain conductors, where the upper conductive layer constituting the curing lines is formed after the doping process, ensuring they are not affected by the doping process and maintaining the integrity of the PSA curing circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If curing lines are fabricated from a layer formed simultaneously with the gate of the active device, then the curing circuit can be integrated with the active device structure, but the curing lines are easily affected by the doping process and peel off from the substrate
Solution Approach 1:
The patent divides the curing line structure into multiple layers: a lower conductive layer formed with the gate electrode layer, and an upper conductive layer formed after the doping process. This segmentation allows the curing line to be constructed from layers that are not affected by the doping process, preventing peeling while maintaining integration with the active device structure.
Solution Approach 2:
The lower conductive layer of the curing line is formed in advance together with the gate electrode layer, before the doping process. This preliminary action ensures that the foundational layer is already in place and will not be affected by subsequent doping operations, preventing adhesion issues.
2Reliability
If the upper conductive layer of curing lines is formed after the doping process, then the curing lines are not affected by the doping process and maintain integrity, but the fabrication process becomes more complex
Solution Approach 1:
The patent merges the formation of the upper conductive layer of the curing line with the formation of other conductive structures in the display device (such as source/drain conductors) in the same fabrication step. This merging approach adds minimal complexity to the overall process while ensuring the curing line's integrity.
3Device complexity
If curing lines are disposed in the circuit region, then the PSA curing circuit can be integrated with the display device, but the curing lines may interfere with subsequent doping processes
Solution Approach 1:
The patent resolves the interference issue by transitioning to a multi-layer vertical structure. The lower conductive layer is positioned in the circuit region for integration, while the upper conductive layer is positioned above the doping region, allowing the curing line to function in the circuit region without interfering with the doping process in the vertical dimension.
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 prevents the peeling of curing lines, allowing for successful curing and alignment of the liquid crystal layer, thereby enhancing the yield rate and quality of the display panels by ensuring the PSA curing circuit operates normally.
Implementation Method 1
The LC layer is irradiated by a light under the curing predetermined voltage. The reactive monomers are then polymerized and cured to form a polymer layer simultaneously on the substrate at respective sides of the LC layer.
Data Source
AI summary
An active device array mother substrate including a substrate, pixel arrays, and a polymer-stabilized alignment curing circuit is provided. The substrate has panel regions, a circuit region, a first cutting line, and a second cutting line. The first cutting line is disposed on the circuit region between an edge of the substrate and the second cutting line. The active devices of the pixel arrays have a semiconductor layer. The polymer-stabilized alignment curing circuit disposed on the circuit region includes curing pads disposed between the edge of the substrate and the first cutting line and curing lines having an upper conductive layer connected to the corresponding curing pads and the corresponding pixel array. The upper conductive layer is in the same layer as the source/drain conductor. Therefore, the curing lines are capable of preventing problems such as peeling, so as to keep the polymer-stabilized alignment curing circuit operating normally.