Array Substrate Blocking Units Prevent Alignment Layer Spreading
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Solution Overview
Problem
Existing liquid crystal displays face issues with fine stains due to damage on organic insulating layers caused by plasma ablation during the removal of residual liquid crystal alignment layers from electrode pads, necessitating a process to prevent these layers from remaining on the pads without additional plasma processing.
Innovation Solution
An array substrate design that includes blocking units on the pad and dummy units to prevent the liquid crystal alignment layer from spreading, featuring grooves and metal patterns that effectively confine the alignment layer, allowing for the omission of a separate plasma process for removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If plasma ablation is used to remove residual liquid crystal alignment layer from electrode pads, then the alignment layer is effectively removed, but fine stains occur due to damage on the organic insulating layer
Solution Approach 1:
The patent applies preliminary action by forming a blocking unit (comprising inorganic insulating film and metal pattern) before the alignment layer coating process. This blocking unit prevents the alignment layer from spreading onto the electrode pad in the first place, eliminating the need for subsequent plasma ablation removal and avoiding the harmful effects of plasma processing on the organic insulating layer.
2Reliability
If a separate plasma process is added to remove the liquid crystal alignment layer from the pad unit, then the electrode pad conductivity is improved, but the process complexity and manufacturing time increase
Solution Approach 1:
The blocking unit is formed in advance during the existing manufacturing process sequence, preventing alignment layer contamination before it occurs. This eliminates the need for an additional plasma removal process, maintaining electrode pad conductivity while reducing overall process complexity.
Solution Approach 2:
The patent extracts the alignment layer blocking function from the post-coating removal process and integrates it into the pre-coating structure formation process. By taking out the prevention function and implementing it earlier, the harmful plasma removal step becomes unnecessary.
3Stability of the object's composition
If the liquid crystal alignment layer spreads to the pad unit beyond the dummy unit, then complete coating is achieved, but the alignment layer remains on the electrode pad causing poor electrical conductivity
Solution Approach 1:
The blocking unit is strategically positioned only at the boundary between the display unit and pad unit, creating a localized barrier with different properties (inorganic insulating film and metal pattern) than the surrounding areas. This local quality change prevents alignment layer spreading onto the electrode pad while allowing complete coating coverage in the display unit area.
Data Source
AI summary
An array substrate for liquid crystal displays and a liquid crystal display including the same. The array substrate includes a display unit including a thin film transistor, a pad unit disposed at one side of the display unit, and a dummy unit disposed at the other side of the display unit. Here, a blocking unit for blocking a liquid crystal alignment layer from spreading is disposed on each of the pad and dummy units. A first blocking unit for blocking the liquid crystal alignment layer from spreading to the pad unit is disposed on the pad unit. A second blocking unit for blocking the liquid crystal alignment layer from spreading to the dummy unit is disposed on the dummy unit. The liquid crystal alignment layer can be blocked from spreading to the pad unit or to a pad unit of an adjacent array substrate in manufacture of a liquid crystal display, thereby enabling omission of a separate process for removing the liquid crystal alignment layer on the pad unit.