Flexible Printed Circuit Board Magnetic Shielding for Disk Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In disk devices like hard disk drives, the close proximity of conductors on flexible printed circuit boards can lead to performance issues due to reduced spacing, causing potential contamination and noise transmission, as well as increased risk of short circuits and dielectric breakdown.
Innovation Solution
The implementation of a flexible printed circuit board with a base layer, a conductive layer, and an insulating cover layer, featuring through holes and protrusions that separate conductors and prevent flux and underfill mixing, while also providing insulation and reducing parasitic impedance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conductors are mounted at higher density on the flexible printed circuit board, then the functionality and integration of the disk device is improved, but the distance between adjacent conductors is reduced causing performance degradation
Solution Approach 1:
The patent introduces a magnetic shielding layer as an intermediary structure between adjacent conductors on the flexible printed circuit board. This shielding layer acts as a mediator that blocks magnetic field interference between closely spaced conductors, enabling high conductor density while maintaining signal transmission quality. The shielding layer is positioned between the conductors and forms a magnetic barrier that prevents cross-talk and noise transmission.
Solution Approach 2:
The patent segments the space between adjacent conductors by introducing magnetic shielding structures that divide the electromagnetic field environment. This segmentation creates isolated magnetic field zones around each conductor, preventing interference between neighboring signal lines. The shielding layer is divided into multiple segments corresponding to different conductor pairs, allowing independent optimization of each signal path.
2Area of stationary object
If conductors are placed closer together, then the circuit board size is reduced, but the risk of short circuits and dielectric breakdown increases
Solution Approach 1:
The magnetic shielding layer serves as a protective intermediary between adjacent conductors, preventing direct electromagnetic coupling that could lead to short circuits. The shielding layer is positioned between conductors at minimal spacing, creating a magnetic barrier that eliminates the harmful effect of close proximity while maintaining compact board dimensions.
Solution Approach 2:
The patent applies magnetic shielding as a preventive measure before short circuits or dielectric breakdown can occur. By pre-installing the shielding layer between conductors, the design cushions against potential electromagnetic interference and insulation failure that would otherwise result from reduced conductor spacing.
3Adaptability or versatility
If conductor spacing is reduced, then the flexible printed circuit board can accommodate more connections, but noise transmission between conductors increases
Solution Approach 1:
The magnetic shielding layer acts as a noise-blocking intermediary between adjacent conductors. It absorbs and redirects magnetic field energy, preventing noise from one conductor from coupling into adjacent signal lines. This allows the flexible printed circuit board to achieve high connection capacity while maintaining signal integrity through effective noise isolation.
Solution Approach 2:
The patent applies magnetic shielding selectively at specific locations where conductor spacing is reduced and noise interference is most likely to occur. The shielding layer is positioned locally between critical signal pairs, providing targeted noise protection while maintaining overall board versatility and connection capacity.
Data Source
AI summary
A disk device according to one embodiment includes a magnetic disk, a magnetic head, and a flexible printed circuit board. The flexible printed circuit board is electrically connected to the magnetic head. The flexible printed circuit board includes a first layer, a second layer having conductive property, and a third layer having insulation property. The first layer includes a first surface having insulation property. The second layer overlays the first surface, and includes a first conductor and a second conductor spaced from the first conductor. The third layer covers at least a part of the first surface and at least a part of the second layer. The flexible printed circuit board is provided with a first hole that is located between the first conductor and the second conductor with spacing from the second layer and penetrates the third layer.