Tapered Magnetic Head Shields for Flux Shunting Control
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Solution Overview
Problem
Current magnetic hard disk drives face challenges in increasing recording density while minimizing flux shunting and adjacent track interference, as existing leading and side shields reduce the main pole's write field, which is already weak in perpendicular magnetic write heads.
Innovation Solution
A tapered leading and side shield topology is introduced, featuring a main pole with a trapezoidal cross-section, a leading shield with varying throat height, side shields with different throat heights at leading and trailing gaps, and a trailing gap, to balance fringe field suppression with maintaining write field strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional leading and side shields are used, then adjacent track interference is reduced, but the main pole's write field strength is significantly reduced
Solution Approach 1:
The shield structure is divided into multiple segments with different throat heights along the cross-track direction. The first shield segment has a first throat height and the second shield segment has a second throat height, creating local variations in magnetic flux shunting capability. This local quality differentiation allows the shield to suppress fringe fields effectively while preserving write field strength in critical regions.
Solution Approach 2:
The shield is segmented into multiple portions (first shield portion, second shield portion) with different geometric characteristics. Each segment can be independently optimized for its specific function - one segment may focus on fringe field suppression while another maintains write field integrity. The segmentation allows complex magnetic field management through simpler, modular components.
2Object-affected harmful factors
If shield throat height is increased, then fringe field suppression improves, but flux shunting increases
Solution Approach 1:
Different regions of the shield have different throat heights optimized for their local requirements. The variation in throat height along the cross-track direction creates zones with different magnetic flux shunting characteristics, allowing effective fringe field suppression where needed while minimizing unnecessary flux shunting in other regions.
Solution Approach 2:
The shield throat height is made variable rather than uniform, creating a dynamic magnetic field management system. The changing throat height geometry allows the shield to adapt its flux shunting behavior to the local magnetic field distribution, suppressing fringes where the throat is larger while maintaining openness where write field strength is critical.
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 optimizes flux shunting, enhancing write field strength and gradient, thereby improving recording density without significantly reducing the main pole's write field, addressing the limitations of conventional shield topologies.
Implementation Method 1
This design optimizes flux shunting, enhancing write field strength and gradient
Data Source
AI summary
In one embodiment, a magnetic head includes a main pole having a trapezoidal cross-section at a media-facing surface thereof and a flared shape with a greater width in a cross-track direction at positions away from the media-facing surface, a leading shield positioned near a leading side of the main pole, wherein a leading gap is provided between the main pole and the leading shield, side shields positioned on both sides of the main pole in the cross-track direction adjacent the media-facing surface of the main pole, with side gaps provided between the main pole and both of the side shields, and a trailing gap provided on a trailing side of the main pole at the media-facing surface thereof, with a throat height of the side shields being less than the throat height of the side shields at a position closer to the trailing gap than the leading gap.