Flexible Array Substrate Double-Sided Circuit Manufacturing
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Solution Overview
Problem
The existing methods for manufacturing flexible array substrates with double-sided circuit structures face challenges such as poor flatness and low yield due to the complexity of peeling and re-attaching processes, which hinder the achievement of ultra-slim bezel or bezel-free displays, especially as resolution increases.
Innovation Solution
A method involving the sequential formation of an adhesive layer, passivation layer, back-side drive circuit, planarization layer, flexible backing plate, and front-side drive circuit on a rigid support plate, followed by peeling off the support plate and adhesive layer to create a flexible array substrate with a double-sided circuit structure, eliminating the need for peeling and re-attaching steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the flexible backing plate is peeled off and re-attached to form a double-sided circuit structure, then both front and back surfaces can have circuits, but poor flatness and low yield occur due to incorrect attachment
Solution Approach 1:
The adhesive layer is formed on the rigid base plate before forming the flexible backing plate, preparing the attachment interface in advance. This preliminary action ensures that when the flexible backing plate is peeled and re-attached, the adhesive is already in position to maintain flatness and prevent attachment errors, thus enabling double-sided circuit formation while maintaining manufacturing precision.
Solution Approach 2:
The adhesive layer acts as an intermediary between the rigid base plate and the flexible backing plate. It facilitates the peeling and re-attachment process while maintaining proper alignment and flatness, enabling the formation of double-sided circuit structures without the poor flatness and low yield associated with direct attachment methods.
2Adaptability or versatility
If the flexible backing plate is peeled off and re-attached to form a double-sided circuit structure, then both front and back surfaces can have circuits, but the fabrication process becomes difficult and yield decreases
Solution Approach 1:
The adhesive layer is pre-formed on the rigid base plate before the flexible backing plate is created. This preliminary preparation simplifies the subsequent peeling and re-attachment process, making the fabrication of double-sided circuit structures easier and more reliable, thereby improving ease of manufacture while maintaining the double-sided circuit capability.
Solution Approach 2:
The adhesive layer serves as an intermediary that simplifies the fabrication process. It enables controlled peeling and re-attachment of the flexible backing plate without requiring complex alignment or attachment procedures, reducing fabrication difficulty and improving yield for double-sided circuit structures.
3Device complexity
If WOA lines and GOA circuits are used to connect drive circuits, then drive chips can be removed, but the non-display zone width increases making ultra-slim bezel difficult to achieve
Solution Approach 1:
The circuit connections are moved from the horizontal plane (within the non-display zone) to the vertical dimension (through the flexible backing plate thickness). By forming circuits on both front and back surfaces and connecting them through via holes perpendicular to the substrate, the connection path transitions to the third dimension, eliminating the need for wide non-display zones while maintaining drive chip elimination benefits.
Solution Approach 2:
The circuit connections are nested within the flexible backing plate structure itself. By creating via holes through the flexible backing plate and forming conductive connections between front and back surface circuits, the connection pathways are embedded within the substrate thickness, allowing drive chip elimination without increasing non-display zone width.
Data Source
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AI summary
A method for manufacturing a flexible array substrate, comprising: firstly, continuously forming, on a rigid supporting plate (1), an adhesive layer (2), a passivation layer (3), a back driving circuit (4), a planarization layer (5), a flexible substrate (6), a front driving circuit (8), and a display circuit (9) which are stacked; and secondly, lifting off the rigid supporting plate (1) and the adhesive layer (2) to obtain a flexible array substrate with a double-sided circuit structure. Steps of lifting off, inverting, and secondary partial pasting of the flexible substrate (6) are not required in the whole manufacturing process. The problems of poor flatness and low yield of the flexible substrate (6) subjected to the secondary partial pasting can be avoided, the manufacturing difficulty of the flexible array substrate with a doublesided circuit structure is reduced, and the process yield of the flexible array substrate is improved.