Magnetic Head Side Shields for Perpendicular Recording Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic heads for perpendicular magnetic recording systems face challenges in achieving both improved write characteristics and increased recording density due to unwanted erasure phenomena, where signals on adjacent tracks are erased or attenuated during writing, and existing solutions with side shields suffer from magnetic flux saturation issues.
Innovation Solution
A magnetic head design featuring a main pole and two side shields with specific sidewall configurations and angles, including a gap section between the main pole and the write shield, to minimize magnetic flux saturation and optimize write characteristics while increasing recording density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the end face of the main pole is reduced in width to increase recording density, then recording density is improved, but write characteristics deteriorate due to insufficient cross-sectional area
Solution Approach 1:
The side shields are configured with different distances from the medium facing surface at different locations: closer at the edges to improve write characteristics, and farther at the center to prevent flux saturation. This local variation in geometry allows simultaneous optimization of both write characteristics and recording density.
Solution Approach 2:
The side shields extend in the depth direction (distance from medium facing surface) to provide additional magnetic flux pathways. This three-dimensional configuration allows the main pole to have sufficient cross-sectional area for good write characteristics while the end face width is reduced for high recording density.
2Reliability
If the distance between the medium facing surface and the edge of the side shields is reduced to increase main pole cross-sectional area, then write characteristics are improved, but magnetic flux saturation occurs in the side shields
Solution Approach 1:
Different portions of the side shields have different distances from the medium facing surface: the edges are closer to improve write characteristics, while the center portions are farther to prevent flux saturation. This local differentiation resolves the contradiction between write characteristics and flux saturation.
Solution Approach 2:
The side shields are effectively divided into functional zones: edge regions that are closer to the medium facing surface for improved write characteristics, and center regions that are farther away to prevent magnetic flux saturation. This segmentation allows each zone to perform its specific function optimally.
3Reliability
If the main pole cross-sectional area is increased to improve overwrite property, then write characteristics are improved, but the end face width increases reducing recording density
Solution Approach 1:
The side shields extend in the depth direction (perpendicular to the medium facing surface) to provide additional cross-sectional area for magnetic flux flow. This allows the main pole to have large cross-section for good overwrite property while maintaining small end face width for high recording density.
Solution Approach 2:
The magnetic flux pathway is segmented into the main pole body (providing cross-sectional area for overwrite) and the side shields (extending in depth to prevent saturation). This segmentation allows optimization of both overwrite property and recording density independently.
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 design effectively reduces unwanted erasure and enhances recording density by preventing magnetic flux saturation in the side shields, allowing for improved write characteristics and higher track density.
Implementation Method 1
a coil configured to produce a magnetic field corresponding to data to be written on the recording medium
Implementation Method 2
a main pole configured to pass a magnetic flux corresponding to the magnetic field produced by the coil, and to produce a write magnetic field for writing data on the recording medium
Data Source
AI summary
A first side shield has a first sidewall and a second sidewall, and a second side shield has a third sidewall and a fourth sidewall. The first to fourth sidewalls have first to fourth edges, respectively, that are farthest from a top surface of a substrate. The distance between a rear end of the first edge and a rear end of the third edge in a track width direction is greater than the distance between a front end of the first edge and a front end of the third edge in the track width direction. The distance between the second edge and the fourth edge in the track width direction increases with increasing distance from the medium facing surface.