Foldable FPCB Sealing Structure for Moisture-Resistant Hinges
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Solution Overview
Problem
Electronic devices face challenges in miniaturization due to moisture ingress through flexible printed circuit boards (FPCBs), which can degrade performance and reduce service life.
Innovation Solution
Incorporating a waterproof member in the sealing portion of the FPCB to prevent moisture ingress and improve bending performance, while sealing spaces between openings and layers with a waterproof member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a conventional single layer flexible printed circuit board is used, then the device can be miniaturized, but moisture can enter through the FPCB causing degradation and reduced service life
Solution Approach 1:
The patent applies composite materials by constructing a multi-layer FPCB structure where different layers (conductive layers, insulating layers, sealing layers) are combined to achieve both miniaturization and waterproof performance. The composite structure includes a first FPCB with conductive and insulating layers, and a second FPCB with sealing layers, creating a barrier against moisture ingress while maintaining compact dimensions.
2Reliability
If a multi-layer FPCB structure is implemented, then waterproof performance improves, but device complexity increases
Solution Approach 1:
The patent segments the FPCB into multiple functional layers: conductive layers for electrical connectivity, insulating layers for electrical isolation, and sealing layers for moisture protection. Each layer performs a specific function, allowing the complex waterproofing requirement to be divided into manageable segments that can be independently designed and manufactured.
Solution Approach 2:
The FPCB structure is designed to perform multiple functions simultaneously: the conductive layers provide electrical connectivity, the insulating layers provide electrical isolation, and the sealing layers provide moisture protection. This multi-functionality reduces the need for separate components, thereby managing complexity while achieving comprehensive waterproof performance.
3Reliability
If sealing portions are added to prevent moisture ingress, then waterproof performance improves, but bending performance of the FPCB deteriorates
Solution Approach 1:
The patent applies local quality by providing sealing portions only in specific critical areas where moisture ingress is most likely to occur, rather than making the entire FPCB rigid. The sealing layers are strategically positioned at interfaces and potential moisture pathways, allowing the FPCB to maintain flexibility in non-critical areas while achieving waterproof protection where needed.
Data Source
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AI summary
An electronic device is provided. The electronic device includes a flexible printed circuit board (FPCB) is provided. The electronic device includes a display including a first area and a second area, a first housing supporting the first area, a second housing supporting the second area, a hinge structure connecting the first housing and the second housing to be foldable about a folding axis and allowing the first area and the second area to change between a first state of forming substantially the same plane and a second state of facing each other, a first bracket connecting the first housing and the hinge structure and having a first opening penetrating through a surface thereof, a second bracket connecting the second housing and the hinge structure and having a second opening penetrating through a surface thereof, and a FPCB extending from the first space to the second space across the hinge structure in an extending direction.