Disk Device FPC Wire Angle for Thermal Stress Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flexible printed circuit boards (FPCs) in disk devices, such as hard disk drives, experience thermal stress due to thermal contraction and expansion, which can lead to durability issues and malfunctions.
Innovation Solution
The FPCs are designed with wires extending between fixed parts at an angle of greater than 45 degrees and not exceeding 90 degrees relative to the virtual line connecting these parts, increasing the cross-sectional area orthogonal to the thermal stress direction, thereby enhancing durability against thermal stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the FPC is fixed to components, then electrical connection and structural support are achieved, but thermal stress causes durability issues
Solution Approach 1:
The patent changes the geometric parameter of the wire arrangement by specifying an angle between 45-90 degrees relative to the thermal stress direction. This parameter optimization increases the cross-sectional area orthogonal to the thermal stress, thereby improving the FPC's resistance to thermal stress and enhancing reliability.
Solution Approach 2:
The patent introduces a dimensional approach by considering the angular orientation of wires in three-dimensional space. By arranging wires at specific angles (45-90 degrees) relative to the thermal stress direction, the design adds a dimensional aspect to stress distribution, effectively distributing thermal stress across multiple wire paths and increasing overall durability.
2Reliability
If wires extend between fixed parts, then electrical connection is established, but thermal stress causes damage
Solution Approach 1:
The patent optimizes the geometric parameter of wire extension by specifying an angle between 45-90 degrees relative to the thermal stress direction. This parameter change increases the cross-sectional area of wires orthogonal to the stress direction, thereby reducing stress concentration and improving wire durability against thermal stress.
Solution Approach 2:
The patent employs composite structural design by combining multiple wires arranged at specific angles to form a composite wiring structure. This composite arrangement distributes thermal stress across multiple conductive paths, enhancing the overall stress resistance and durability of the wire assembly.
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
This configuration improves the durability of the wires and the overall disk device by reducing the risk of damage from thermal stress, leading to reduced malfunctions and increased reliability.
Implementation Method 1
the FPC may be subjected to thermal stress due to thermal contraction and/or thermal expansion of its own
Implementation Method 2
the FPC may be subjected to thermal stress due to thermal contraction and/or thermal expansion of its own
Data Source
AI summary
According to one embodiment, a disk device includes a recording medium, a first magnetic head, a first wiring member, a flexible printed circuit board, and a wire. The first wiring member is electrically connected to the first magnetic head. The flexible printed circuit board includes a surface, a first fixed part fixed to a first component, and a second fixed part fixed to a second component, and is electrically connected to the first magnetic head through the first wiring member. The wire on the flexible printed circuit board extends along the surface such that the wire extends between the first fixed part and the second fixed part in a direction intersecting at an angle of lager than 45 degrees and not larger than 90 degrees with an extending direction of a virtual shortest line that connects the first fixed part to the second fixed part along the surface.