Touch Substrate Signal Line Layout for Crack-Free Bending Areas
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In flexible display apparatuses using the FMLOC technique, the inorganic layer between double-layer metal traces cracks when bent at large angles, leading to peeling and affecting the product's service life.
Innovation Solution
The touch substrate design includes a first and second touch signal sub-line configuration in the bending area where the orthographic projection of the first sub-line is located within the projection of the second sub-line, with a controlled distance and insulating layer arrangement to prevent cracks and extend the product's lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a double-layer metal trace with inorganic layer is used in the bending area, then the touch substrate can achieve foldable functionality, but the inorganic layer cracks when bent at large angles leading to peeling and reduced service life
Solution Approach 1:
The patent removes the inorganic layer from the bending area entirely, extracting the problematic component that causes cracking during large-angle bending. This extraction eliminates the source of reliability issues while preserving the foldable functionality through the remaining organic encapsulation layer and adjusted trace configuration.
Solution Approach 2:
The patent applies different structural configurations to different areas of the touch substrate. The bending area uses a simplified single-layer trace structure without inorganic layer, while non-bending areas can maintain the original double-layer structure. This local differentiation optimizes each area for its specific functional requirements.
2Reliability
If the inorganic layer is removed in the bending area, then cracks are prevented and service life is extended, but the trace structure must be redesigned to maintain signal transmission
Solution Approach 1:
The inorganic layer is extracted from the bending area, removing the source of cracking. The resulting simplified single-layer trace structure reduces structural complexity compared to the original double-layer configuration, while maintaining adequate signal transmission capability for the bending application.
3Reliability
If the orthographic projection of the first sub-line is located within the projection of the second sub-line, then the insulating layer is protected from cracks, but the signal transmission path is constrained
Solution Approach 1:
The first touch signal sub-line is positioned within the orthographic projection of the second touch signal sub-line, creating a nested configuration. This nesting protects the insulating layer between the two sub-lines from cracking during bending, as the overlapping projections ensure the insulating layer remains under compression rather than tension. The signal transmission path is maintained through this protected configuration.
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The present disclosure provides a touch substrate and a display apparatus, which are used to prevent cracks in a bending area of the touch substrate. The touch substrate provided in embodiments of the present disclosure comprises a base and a plurality of touch signal lines. The base comprises a bending area and a non-bending area located beyond the bending area. The bending area extends in a first direction. The plurality of touch signal lines are located on one side of the base. At least some of the touch signal lines extend to the bending area. Each of the plurality of touch signal lines comprises: a first sub-touch signal line and a second sub-touch signal line on the side of the first sub-trace line away from the base. In the bending area, the orthographic projection of the first sub-touch signal line on the base falls within the orthographic projection of the second sub-touch signal line on the base.