Array Substrate Discontinuous Common Electrode Routing
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Solution Overview
Problem
In the two-step etching process for low temperature poly-silicon array substrates, wet etching leads to etchants remaining between routing layers, causing over-etching and resulting in thin or broken gate and common electrode routings, which affects the yield and reliability of display panels.
Innovation Solution
The design includes a first metal layer with parallel gate and common electrode routings, a second metal layer with connecting portions, and insulating layers with through holes, allowing adjacent spacers to be electrically connected, creating channels for etchant flow and preventing over-etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If wet etching is used in the first etching step, then etching cost is reduced and etching taper angle is improved, but etchants remain between routing layers causing over-etching and routing damage
Solution Approach 1:
The common electrode routing is segmented into multiple discontinuous segments (first common electrode routing segment, second common electrode routing segment, etc.) separated by intervals. This segmentation creates flow channels that allow etchants to escape during wet etching, preventing over-etching while maintaining the benefits of wet etching methodology
Solution Approach 2:
The intervals between discontinuous common electrode routing segments act as intermediary flow channels. These intervals mediate the etching process by providing escape paths for etchants, thereby protecting the gate routing from over-etching damage while allowing wet etching to proceed
2Manufacturing precision
If wet etching is used, then etching taper angle is improved, but etchants cannot be washed away quickly causing over-etching
Solution Approach 1:
The common electrode routing is divided into discontinuous segments with intervals between them. These intervals serve as drainage channels that accelerate etchant removal during and after the etching process, reducing etchant residence time while preserving the superior taper angle achieved by wet etching
Solution Approach 2:
The intervals between routing segments function as fluid flow channels that facilitate rapid removal of etchants through hydraulic flow. This design enables quick washing away of etchants, reducing their residence time and preventing over-etching while maintaining wet etching's superior taper angle
3Reliability
If common electrode routing is made discontinuous with spacers, then etchant flow channels are created preventing over-etching, but device complexity increases
Solution Approach 1:
The discontinuous common electrode routing segments serve multiple functions: they maintain the common electrode's electrical function while simultaneously creating etchant flow channels. This multi-functionality prevents over-etching without requiring additional dedicated structures, thereby limiting the increase in device complexity
Solution Approach 2:
The common electrode routing itself serves the dual purpose of providing electrical connection and creating etchant drainage channels. The routing structure is self-sufficient in solving the over-etching problem without requiring separate protective structures, thus minimizing added complexity
Data Source
AI summary
The present invention provides an array substrate and a display panel, the array substrate comprises: a first metal layer comprising a plurality of gate routings and a plurality of common electrode routings, at least one of the plurality of common electrode routings is arranged discontinuously and comprises a plurality of common electrode spacers spaced apart from each other; a second metal layer comprising a plurality of common electrode connecting portions; and a first insulating layer provided with a plurality of first through holes, adjacent two of the plurality of common electrode spacers are electrically connected to a common electrode connecting portion through two of the plurality of first through holes.