Air Bearing Surface Pressurizing Steps for Slider Roll Stability
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Solution Overview
Problem
Magnetic hard disk drives face challenges in maintaining optimal flying height and reducing slider roll angle sensitivity to changes in radial positioning, which can lead to excessive roll angles and corner contacts with the disk, affecting tribological performance and reliability.
Innovation Solution
The design incorporates an air bearing surface with a primary plane, sub-ambient pressure cavities, leading pads, and pressurizing steps to reduce flying height sensitivity and maintain a stable slider position, featuring a trailing pad and leading pads with specific recessions and pressurizing steps to manage air pressure and reduce slider roll angle changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the flying height is reduced to increase areal density, then data storage capacity is improved, but tribological performance and reliability deteriorate
Solution Approach 1:
The air bearing surface incorporates localized features including leading pressurizing steps with short and long regions, sub-ambient pressure cavities, and trailing pads at specific positions. These local structural variations create zones of different air pressure and bearing characteristics, allowing optimized flying height for high areal density while maintaining sufficient air bearing thickness in critical areas to preserve tribological performance and reliability.
2Adaptability or versatility
If the slider roll angle becomes excessive, then the air bearing may become thinner at the corner, but this degrades tribological performance
Solution Approach 1:
The air bearing surface includes leading pressurizing steps positioned upstream of the leading pad, sub-ambient pressure cavities, and trailing pads that collectively create a preliminary air pressure distribution pattern. This pre-established pressure distribution counteracts the thinning effect of excessive roll angle by maintaining sufficient air bearing thickness at the corner regions, thereby preventing degradation of tribological performance while allowing flexible slider positioning.
3Quantity of substance
If the flying height is reduced, then areal density increases, but the air bearing cannot be eliminated entirely to reduce friction and wear
Solution Approach 1:
The air bearing surface incorporates sub-ambient pressure cavities and leading pressurizing steps that dynamically adjust air pressure parameters across different regions. The sub-ambient pressure cavities create low-pressure zones that reduce air bearing thickness and friction, while the leading pressurizing steps create high-pressure zones that maintain adequate bearing thickness. This parameter variation allows optimized flying height for high areal density while maintaining sufficient air bearing to reduce friction and wear.
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 design enhances the stability of the slider's air bearing, reducing the sensitivity of the roll angle to changes in slider skew and minimizing the risk of corner contacts, thereby improving the tribological performance and reliability of the information storage device.
Implementation Method 1
the transducer is typically supported in very close proximity to the magnetic disk 102 by a hydrodynamic air bearing. As the motor 104 rotates the magnetic disk 102, the hydrodynamic air bearing is formed between an air bearing surface of the slider of the head, and a surface of the magnetic disk 102.
Implementation Method 2
The ABS includes a trailing pad adjacent the transducer, defining a primary ABS plane... The ABS also includes a sub-ambient pressure cavity being recessed from the primary plane by a cavity depth in the range 0.8 to 2 microns... The ABS also includes left and right leading pressurizing steps each being recessed from the primary plane by a pressurizing step depth in the range 0.05 to 0.5 microns.
Data Source
AI summary
A head has an air bearing surface with left and right leading pressurizing steps. The left and right leading pressurizing steps are each partially surrounded by left and right leading pads, respectively. The left leading pressurizing step includes a left short region that extends for a first distance (measured parallel to the slider longitudinal axis) from the leading face of the slider to the left leading pad. The left leading pressurizing step also includes a left long region that extends for a second distance (measured parallel to the longitudinal axis) from the leading face to the left leading pad. The second distance is at least 25% greater than the first distance. The left short region is disposed closer to the left lateral face than is the left long region. The left long region is disposed closer to the longitudinal axis than is the left short region.