Floating Side Shields in Write Heads for Magnetic Flux Control
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Solution Overview
Problem
Current disk drive write head designs with side shields connected to the write shield suffer from magnetic flux leakage and difficulty in controlling gap distances, leading to inefficiencies and manufacturing challenges, which affect data storage density and reliability due to fringe field effects on neighboring tracks.
Innovation Solution
A write head design featuring floating side shields separated from the pole tip and write shield by a non-magnetic material, allowing for precise control of gap distances and magnetic potentials to minimize magnetic flux leakage while protecting adjacent tracks from fringe fields, using a manufacturing process that separates the side shields and pole tip in the same step for improved control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If side shields are connected to the write shield, then fringe field effects on neighboring tracks are reduced, but magnetic flux leakage increases and manufacturing precision deteriorates
Solution Approach 1:
The side shields are segmented from the write shield by a nonmagnetic material, creating separate magnetic circuits. This segmentation prevents magnetic flux from leaking into the side shields while maintaining the fringe field shielding function. The side shields operate independently with their own magnetic potential, disconnected from the write shield's magnetic circuit.
Solution Approach 2:
A nonmagnetic material is introduced as an intermediary between the side shields and the write shield. This intermediary blocks the magnetic flux path that would otherwise connect the side shields to the write shield, preventing flux leakage while allowing the side shields to maintain their protective function against fringe fields.
2Object-affected harmful factors
If side shields are connected to the write shield, then fringe field effects are reduced, but gap distance control becomes difficult
Solution Approach 1:
By segmenting the side shields from the write shield using a nonmagnetic material, the structure allows for independent positioning and spacing control. The nonmagnetic spacer acts as a physical reference that defines the gap distance, making it easier to control during manufacturing processes like plating and polishing.
Solution Approach 2:
The nonmagnetic material serves as a physical intermediary that defines and maintains the gap distance between the side shields and write shield. This intermediary structure provides a controlled spacing mechanism that simplifies manufacturing precision by establishing a fixed reference distance.
3Quantity of substance
If track width decreases to increase storage density, then data storage density improves, but fringe field effects on adjacent tracks worsen
Solution Approach 1:
The side shields provide localized magnetic shielding specifically at the boundaries between tracks. By placing side shields adjacent to the pole tip on both sides, the solution creates localized protection zones that counteract fringe field effects on neighboring tracks, enabling tighter track spacing without compromising data integrity.
Solution Approach 2:
The side shields are positioned in advance to preemptively block fringe field effects before they can affect adjacent tracks. By having the side shields in place during the write operation, they actively counteract the fringe field emission from the pole tip, preventing inadvertent erasures on neighboring tracks.
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 floating side shield design reduces magnetic flux leakage and enhances data storage density by minimizing fringe field effects on neighboring tracks, improving the efficiency and reliability of disk drives while simplifying the manufacturing process.
Implementation Method 1
the fringe magnetic field emitted by the write pole tip during a write operation affects the magnetic storage state of bits on a neighboring track
Implementation Method 2
side shields connected to a downstream pole of the write head for the reduction of fringe fields emitted from the write pole tip
Data Source
AI summary
A write head has a pole tip, a write yoke connected to the pole tip, a write return yoke, a write shield, and one or more side shields disposed in close proximity to the pole tip. The write return yoke connects to the write yoke on one end and the write shield on a different end. The one or more side shields are separated from the pole tip and write shields by a non-magnetic material and therefore are “floating” and not directly coupled to the write shield or pole tip.