Sound Device FPC Routing for Magnetic Field and Vibration Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sound devices in portable mobile terminals suffer from significant magnetic field loss and vibration interference due to the placement of solder pads and FPCs, which negatively impact sound quality and reliability.
Innovation Solution
A sound device design featuring a frame with a magnet system and dual vibration systems, where FPCs have elastic portions spaced apart from yokes, avoiding interference and enhancing magnetic field performance by eliminating the need for avoidance grooves, and ensuring secure fixation during vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the solder pad is arranged outside the coil and an avoidance groove is provided on the side yoke, then the solder pad can be accommodated, but there is still loss of magnetic field BL
Solution Approach 1:
The FPC is bent at a bending portion to extend in a direction substantially perpendicular to the vibration direction, changing the spatial arrangement from a linear path that intersects the yoke to a L-shaped path that avoids the yoke. This dimensional change in the FPC's layout allows the solder pad to be positioned outside the coil without creating an avoidance groove in the yoke, thereby eliminating magnetic field loss while maintaining manufacturability.
2Volume of moving object
If the FPC is positioned close to the yoke for compact design, then device size is reduced, but the FPC may collide with the side yoke during vibration
Solution Approach 1:
The FPC incorporates an elastic portion that can deform elastically in response to vibration forces. This dynamic flexibility allows the FPC to accommodate vibration movements without colliding with the rigid yoke structure, maintaining reliability while enabling a compact device design. The elastic portion acts as a compliant element that absorbs mechanical stress during operation.
3Ease of manufacture
If the FPC is made rigid for structural stability, then manufacturing is simplified, but the FPC cannot accommodate vibration movements
Solution Approach 1:
The FPC is divided into distinct functional segments: a rigid fixation portion for stable mounting, a flexible elastic portion for vibration accommodation, and a bending portion for spatial routing. This segmentation allows each part to perform its specific function optimally - the rigid portions provide structural stability and ease of manufacture, while the elastic portion ensures reliability during vibration by deforming elastically to avoid collision with the yoke.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design improves magnetic field performance and vibration reliability by preventing interference between FPCs and yokes, thus enhancing sound quality and device durability.
Implementation Method 1
a coil configured to drive the diaphragm
Implementation Method 2
a first elastic portion connecting the first fixation portion with the first welding portion; the first elastic portion is spaced apart from the first side yoke along a vibration direction
Data Source
AI summary
The present disclosure discloses a sound device including a frame, a magnet system, a first vibration system and a second vibration system. The magnet system includes a first inner yoke, a main magnet, a side magnet, a first side yoke, and a connection portion. A first coil of the first vibration system is inserted in to a first magnetic gap. A first FPC of the first vibration system includes a first fixation portion, a first welding portion welded to the first coil, and a first elastic portion connecting the first fixation portion with the first welding portion; the first elastic portion is spaced apart from the first side yoke along a vibration direction; the first welding portion is fixed to a side of the first side yoke facing the first diaphragm. The sound device has better magnetic field performance and vibration performance.