Magnetic Head Slider with Step Portions for Flying Height Control
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Solution Overview
Problem
Magnetic head assemblies in disk devices face challenges in maintaining consistent flying height across the magnetic disk, leading to fluctuations and potential damage at the inner peripheral side due to rough surfaces, while increasing flying height there results in increased flying height at the outer peripheral side, compromising recording accuracy and density.
Innovation Solution
The magnetic head assembly features a slider with a negative-pressure cavity, a leading step portion, sidestep portions, a trailing step portion with a trailing pad and adjustment recess, which generates controlled positive and negative pressures to stabilize flying height, allowing increased flying height at the inner peripheral side without increasing it at the outer peripheral side.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the flying height of the magnetic head assembly is increased on the inner peripheral side of the disk, then the head assembly can avoid contacting the rugged disk surface and prevent damage, but the flying height on the outer peripheral side inevitably increases as well, compromising recording accuracy and density
Solution Approach 1:
The slider surface is designed with different structural features at different radial positions: a leading step portion at the inner peripheral side and a trailing step portion at the outer peripheral side. These local structural variations create different pressure distributions across the slider, allowing the inner peripheral side to have higher flying height for reliability while the outer peripheral side maintains lower flying height for recording accuracy.
2Stability of the object's composition
If a negative-pressure cavity or dynamic pressure generating groove is formed near the center of the facing surface to prevent flying height fluctuations, then flying height stability improves, but the structure becomes more complex
Solution Approach 1:
Instead of forming a single large negative-pressure cavity, the slider surface is segmented into multiple functional portions: a leading step portion, a negative-pressure cavity, and a trailing step portion. This segmentation allows each portion to independently control pressure distribution at different radial positions, achieving flying height stability while keeping the overall structure manageable and manufacturable.
3Manufacturing precision
If the flying height is reduced on the outer peripheral side to improve recording density, then recording accuracy improves, but the head assembly becomes more susceptible to disturbance and flying height fluctuations
Solution Approach 1:
The trailing step portion at the outer peripheral side of the slider creates a localized pressure distribution that supports the head assembly at lower flying heights, enabling improved recording density. The local structural feature provides sufficient aerodynamic support to maintain stability even at these reduced heights, preventing excessive susceptibility to disturbance.
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 stabilizes the flying height and reliability of the magnetic head assembly, maintaining improved recording accuracy and density by controlling pressure distributions across the disk, ensuring consistent performance despite varying peripheral speeds.
Implementation Method 1
a negative-pressure cavity which is defined by a recess formed in the facing surface and generates a negative pressure
Implementation Method 2
an airflow is generated between the disk in rotation and the slider. Based on the principle of aerodynamic lubrication, a force (positive pressure) to fly the slider above the recording surface of the disk acts on the facing surface of the slider
Data Source
AI summary
According to one embodiment, a slider of a head includes a trailing step portion which protrudes from a facing surface of the slider, is situated on the downstream side of a negative-pressure cavity with respect to an airflow, and has a top surface, a trailing pad which protrudes from the top surface, and an adjustment recess which is formed in the top surface on the upstream side of the trailing pad with respect to the airflow and is shallower than the negative-pressure cavity. The adjustment recess defines a first step portion, which extends across a first direction and hangs from the top surface toward a bottom of the adjustment recess, and a second step portion, which extends across the first direction, is spaced in the first direction from the first step portion, and rises from the bottom of the adjustment recess toward the top surface.