Array Substrate Venting Hole for Impurity Gas Diffusion
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Solution Overview
Problem
In array substrates, impurity gases generated during the annealing process can penetrate through passivation layers and affect the Ion/Ioff characteristics of thin film transistors (TFTs), causing efficacy loss due to the inability to diffuse outward.
Innovation Solution
A venting hole is formed in the passivation layer, allowing impurity gases to escape and preventing them from reaching the active layer, with specific openings positioned relative to the active layer and scanning/data lines to enhance gas diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If passivation layers are provided on upper and lower sides of the organic film layer to insulate metal layers, then insulation between metal layers is improved, but impurity gas cannot be diffused out and penetrates to the active layer affecting TFT characteristics
Solution Approach 1:
The passivation layer is segmented by forming venting holes through it, dividing the continuous insulating structure into sections that allow controlled gas passage while maintaining overall insulation function. This resolves the contradiction by creating localized openings that enable impurity gas escape without compromising the general insulation between metal layers.
Solution Approach 2:
The venting hole acts as an intermediary channel between the organic film layer and the external environment, providing a dedicated pathway for impurity gas to escape. This mediator structure allows the passivation layer to simultaneously maintain its insulation function while enabling controlled gas diffusion away from the active layer.
2Object-affected harmful factors
If venting holes are formed in the passivation layer to allow impurity gas escape, then impurity gas diffusion is improved, but the passivation layer's insulating function may be compromised
Solution Approach 1:
The passivation layer is designed with local quality variation: most of the layer maintains continuous insulating properties, while specific localized regions contain venting holes for gas escape. This local modification allows the structure to simultaneously achieve impurity gas diffusion and maintain overall insulation between metal layers.
Solution Approach 2:
The passivation layer incorporates porous features through venting holes, transforming from a completely dense structure to one with controlled porosity. This porous design enables impurity gas to diffuse outward through the designated openings while the majority of the layer retains its insulating function.
3Manufacturing precision
If the organic film layer is annealed during manufacturing to improve film quality, then film performance is improved, but impurity gas is volatilized and trapped causing TFT efficacy loss
Solution Approach 1:
The venting holes are formed in the passivation layer before the annealing process, preparing an escape pathway in advance. This preliminary action ensures that when impurity gas is generated during subsequent annealing, it can immediately escape through the pre-formed vents rather than being trapped and penetrating to the active layer.
Solution Approach 2:
The impurity gas generated during annealing, which would normally be a harmful byproduct, is converted into a manageable flow by directing it through the venting holes to the external environment. This transforms the harmful gas generation into a controlled release process that does not compromise TFT characteristics.
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 venting hole effectively discharges impurity gases, ensuring the TFTs' characteristics are not compromised, thereby maintaining their efficacy and performance.
Implementation Method 1
Impurity gas is easily volatilized during annealing process. Upper and lower sides of the organic film layer are generally provided with passivation layers, so that the impurity gas cannot be diffused out
Data Source
AI summary
An array substrate, a method for manufacturing the array substrate and a display device are provided. The array substrate includes a substrate, an organic film layer and a passivation layer; the organic film layer is arranged between the substrate and the passivation layer; a venting hole is formed in the passivation layer.