Touch Panel Edge Protection via Layer Retraction
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Solution Overview
Problem
Conventional touch panel manufacturing processes result in rough, cracked edges with particle defects, leading to reduced strength and ineffective chemical strengthening due to gaps in the protecting layer, allowing hydrofluoric acid to corrode film layers and cause light leakage.
Innovation Solution
A touch panel design featuring a step-shaped structure with the insulating and protecting layers retracted from the substrate edge, forming a secure bonding with the black matrix layer, and an optional blanking layer to cover the black matrix layer, reducing the slope and preventing acid corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the insulating layer and protecting layer extend to the substrate edge for complete coverage, then the film layers are fully protected, but the edges become rough and cracked with particle defects causing acid corrosion
Solution Approach 1:
The patent extracts the problematic edge regions from the film layer structure by retracting the insulating and protecting layers from the substrate edge. This creates a step-shaped structure where the film layers do not extend to the very edge, eliminating the source of edge defects (roughness, cracks, particles) that would otherwise compromise protection effectiveness during chemical strengthening
Solution Approach 2:
The patent introduces a vertical dimension (step-shaped structure) to solve the edge protection problem. By creating height differences through retracted layers, the design prevents acid from reaching the substrate edge while maintaining complete coverage over the functional areas, thus resolving the contradiction between full protection and edge quality
2Area of stationary object
If the protecting layer is bonded directly to the substrate edge, then maximum coverage is achieved, but bonding is insecure and gaps allow hydrofluoric acid to corrode film layers
Solution Approach 1:
The patent removes the protecting layer from the substrate edge region, creating a retracted configuration. This extraction eliminates the bonding issues at the edge while maintaining adequate coverage over the functional film layers, preventing acid corrosion without requiring insecure edge bonding
Solution Approach 2:
The black matrix layer serves as an intermediary structure that extends to the substrate edge and provides the bonding interface for the protecting layer. This intermediary approach allows the protecting layer to bond securely to a stable structure (black matrix) rather than directly to the problematic substrate edge, while still achieving effective coverage
3Ease of manufacture
If the insulating layer edge is aligned with the substrate edge for simple manufacturing, then manufacturing complexity is reduced, but the protecting layer develops gaps and bonding failures occur
Solution Approach 1:
The patent extracts the insulating layer from the substrate edge alignment, creating a retracted configuration. This simplifies manufacturing by eliminating the need for precise edge alignment while maintaining adequate coverage, as the layer now bonds to the black matrix layer which provides a stable reference surface
Solution Approach 2:
The black matrix layer is formed first and extends to the substrate edge, providing a pre-established bonding surface. This preliminary action allows subsequent layers (insulating and protecting layers) to be formed without requiring precise alignment to the substrate edge, thereby simplifying the manufacturing process while maintaining precision
Data Source
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AI summary
A touch panel is disclosed, which includes a substrate (1), a black matrix layer (2), and an insulating layer (3). The black matrix (2) is over the substrate (1), the insulating layer (3) is over the black matrix layer (2), and an edge of the insulating layer (3) has a longer distance to an edge of the substrate (1) on a same side of the touch panel than an edge of the black matrix layer (2) on the same side of the touch panel. The touch panel further includes a protecting layer (4) over the insulating layer (3), configured such that an edge of the protecting layer (4) on the same side of the touch panel has a longer distance to the edge of the substrate (1) than the edge of the insulating layer (3). A manufacturing method of the touch panel, and a display apparatus containing the touch panel, are also disclosed.