Conductive Laminated Structure for Foldable Device Bending
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Solution Overview
Problem
Foldable electronic devices face issues with the breakage of conductive traces due to repeated bending, leading to signal transmission disruptions and performance degradation, as conventional materials like metal oxides are brittle and prone to deformation.
Innovation Solution
A conductive laminated structure is introduced, featuring a conductive layer and a thickening layer, where the thickening layer is strategically placed on the tensile side of the bend to enhance folding characteristics and reduce stress-strain, allowing the structure to withstand over 40,000 folds without breakage, with the thickening layer's length and material composition optimized to support the conductive layer effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional conductive layer is used in foldable electronic devices, then the device structure remains simple, but the conductive traces break after repeated bending
Solution Approach 1:
The patent applies composite materials by combining a conductive layer with a thickening layer to form a laminated structure. The conductive layer provides electrical conductivity while the thickening layer provides mechanical strength and bending resistance. This composite structure resolves the contradiction by maintaining reliability through material composition rather than structural complexity.
Solution Approach 2:
The thickening layer is applied locally at specific positions on the conductive layer, particularly at regions prone to stress during bending. This localized reinforcement provides bending resistance where needed most without unnecessarily complicating the entire device structure, thus improving reliability while minimizing added complexity.
2Reliability
If the conductive layer is made thicker to prevent breakage, then bending resistance improves, but the radius of curvature increases
Solution Approach 1:
By using a composite laminated structure with a conductive layer and a thickening layer, the patent achieves high bending resistance without requiring the conductive layer itself to be thick. The thickening layer provides the mechanical strength needed for repeated bending while the conductive layer remains thin, maintaining a small radius of curvature.
Solution Approach 2:
The patent segments the functional requirements by separating the conductive function (handled by the thin conductive layer) from the mechanical strength function (handled by the thickening layer). This segmentation allows each layer to be optimized independently, enabling high bending resistance with a small radius of curvature.
3Reliability
If a thickening layer is added to the conductive layer, then folding endurance improves, but manufacturing complexity increases
Solution Approach 1:
The patent uses composite materials in the form of a laminated structure where the thickening layer is integrated with the conductive layer. This approach improves folding endurance through material composition rather than complex manufacturing processes, as the layers can be deposited or bonded using standard fabrication techniques.
Solution Approach 2:
The thickening layer is applied in advance to the conductive layer during the manufacturing process, before the device is assembled. This preliminary action ensures that the bending resistance is built into the structure during fabrication, simplifying subsequent manufacturing steps and reducing overall manufacturing complexity.
4Reliability
If the thickening layer is made longer to cover more area, then stress distribution improves, but the device area increases
Solution Approach 1:
The thickening layer is applied locally at specific high-stress regions of the conductive layer rather than uniformly across the entire device. This localized application provides effective stress distribution where needed while minimizing the additional device area, as the thickening layer is concentrated only in critical bending zones.
Data Source
AI summary
A conductive laminated structure includes a conductive layer and a thickening layer. The conductive layer extends in a first direction. The thickening layer is disposed over or under the conductive layer. The conductive laminated structure can withstand more than 40,000 folding times without breakage when a radius of curvature R is equal to 3 mm, a folding direction is perpendicular or parallel to the first direction, and a folding angle is 180°. A foldable electronic device is also provided herein.