Flexible Printed Circuit Segmentation for Foldable Hinge Arching
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Solution Overview
Problem
Foldable electronic devices experience issues such as redundant warping and abnormal pressing noise due to the through-shaft FPC accumulating, bending, and arching, which can cause the FPC to adhere closely to and squeeze adjacent components, leading to performance degradation.
Innovation Solution
A flexible printed circuit with a dividing groove that divides the circuit into a first integrated portion and a second multilayer portion, where the first portion has higher hardness and resistance to deformation, and the second portion is more flexible, reducing arching and pressure on adjacent components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a through-shaft FPC is reserved with redundant length to compensate for component tolerances and meet bending requirements, then the FPC can accommodate assembly variations and bending needs, but the redundant length causes the FPC to accumulate, bend, and arch, leading to abnormal pressing noise and potential damage to adjacent components
Solution Approach 1:
The FPC is divided into multiple sections with different structural characteristics. The first section has an integrated structure for stability, while the second section has a multilayer non-integrated structure for flexibility. This segmentation allows the FPC to accommodate redundant length without uniform arching across the entire circuit, reducing the harmful pressing noise while maintaining adaptability to component tolerances.
Solution Approach 2:
Different sections of the FPC are given different structural qualities - the first section near the connector is made more rigid and integrated for stable electrical connection, while the second section is made more flexible with multilayer non-integrated structure to absorb redundant length variations. This local differentiation of structural properties allows the FPC to handle assembly tolerances without generating abnormal pressing noise throughout the entire circuit.
2Object-generated harmful factors
If the FPC is made more flexible to reduce arching and pressure on adjacent components, then the harmful pressing noise is reduced, but the stability and resistance to deformation of the FPC decreases
Solution Approach 1:
The FPC is segmented into a first section with integrated structure providing high strength and resistance to deformation, and a second section with multilayer non-integrated structure providing flexibility. This segmentation allows the circuit to simultaneously achieve both goals - the first section maintains stability and strength, while the second section reduces arching and pressure on adjacent components through its flexible, adaptive structure.
Solution Approach 2:
The FPC exhibits local quality differentiation where the first section near the connector has high rigidity and deformation resistance for stable electrical connection, while the second section has low rigidity and high flexibility to reduce arching and pressure on adjacent components. This spatial variation in mechanical properties resolves the contradiction between overall strength and local flexibility.
3Strength
If the FPC is made more rigid to maintain stability and reduce deformation, then the resistance to deformation increases, but the arching and accumulation of the redundant length becomes more severe, increasing pressure on adjacent components
Solution Approach 1:
The FPC is divided into a first section with integrated rigid structure that resists deformation and maintains stability, and a second section with flexible multilayer structure that accommodates redundant length through controlled flexibility. This segmentation prevents the entire circuit from arching severely while maintaining the necessary deformation resistance for stable operation.
Solution Approach 2:
The FPC has locally differentiated mechanical properties where the first section exhibits high rigidity to maintain stability and resist deformation, while the second section exhibits controlled flexibility to reduce arching and accumulation of redundant length. This local quality variation resolves the contradiction between overall rigidity and shape control.
Data Source
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AI summary
This application provides a flexible printed circuit and an electronic device. The flexible printed circuit comprises at least one moving section arranged along its length direction. By providing a dividing groove in at least one moving section, the dividing groove divides the moving section into a first portion and a second portion. The dividing groove may absorb a deformation generated when the flexible printed circuit bends, and the first portion and the second portion are completely divided and do not affect each other, reducing the deformation of the first portion and the second portion, reducing the overall arching degree of the flexible printed circuit, and reducing the pressure exerted by the flexible printed circuit on adjacent components. As a result, issues such as abnormal pressing noise and film printing of the electronic device can be improved.