Non-Conformal Side Gap Magnetic Head for High Density Recording
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Solution Overview
Problem
Conventional magnetic recording heads face challenges in achieving high recording densities due to difficulties in supplying sufficient magnetic field intensity with narrow main pole widths, reducing erase band width, and minimizing head fringe field interference, while maintaining precise control over side gap width.
Innovation Solution
A magnetic head with a non-conformal side gap is developed, featuring a side gap layer with a groove and a self-aligned side shield layer, where the side gap width is precisely controlled using a method that avoids lithography, allowing for a tapered main pole shape and a 9:1 width ratio between the side gap and side shield, enabling accurate side gap width distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional lithography methods are used to define side gap width, then manufacturing process is simple, but side gap width control accuracy is insufficient
Solution Approach 1:
The patent replaces the lithography-based mechanical patterning system with a self-aligned deposition system. The side gap layer is formed by depositing material that automatically conforms to the main pole geometry, eliminating the need for lithography-defined side gap widths and achieving sub-lithographic precision through physical self-alignment mechanisms.
Solution Approach 2:
The side gap layer material serves itself by automatically conforming to the main pole shape during deposition. The deposition process inherently creates the precise side gap geometry without requiring external lithography patterning or alignment steps, as the material naturally follows the underlying main pole structure.
2Manufacturing precision
If main pole width is narrowed to increase recording density, then recording density improves, but magnetic field intensity becomes insufficient
Solution Approach 1:
The patent applies different gap widths at different locations along the main pole. The side gap layer creates a non-uniform gap structure where the gap width varies along the downtrack direction, with narrower gaps at critical regions to enhance magnetic field intensity while maintaining overall high recording density through the narrowed main pole width.
Solution Approach 2:
The patent changes the gap width parameter along the downtrack direction to optimize magnetic field distribution. By varying the side gap layer thickness or composition, the magnetic circuit parameters are adjusted to maintain sufficient field intensity in the narrowed main pole while achieving high recording density.
3Manufacturing precision
If conventional side gap structure is used, then manufacturing is simpler, but erase band width and ATI cannot be reduced
Solution Approach 1:
The side gap structure is segmented into multiple functional regions along the downtrack direction. The side gap layer is divided into different sections with varying properties, allowing independent optimization of erase band width control and ATI reduction in different regions, achieving multiple performance goals simultaneously.
Solution Approach 2:
The patent employs an asymmetric side gap structure where the gap width differs between the leading and trailing sides of the main pole. This asymmetric configuration enables differential control of magnetic field distribution, allowing reduced erase band width on one side while maintaining adequate field intensity on the other, and reducing ATI through optimized field confinement.
Data Source
AI summary
In one embodiment, a magnetic head includes a main pole having a leading side and a trailing side relative to a downtrack direction, a side gap layer positioned adjacent to the main pole in a crosstrack direction, and a side shield layer positioned adjacent the side gap layer in a crosstrack direction. The downtrack direction is in a direction of medium travel relative to the main pole, the crosstrack direction is perpendicular to the downtrack direction, the side gap layer is characterized by having a groove therein in the downtrack direction having the main pole positioned therein, the side shield is characterized by having a groove formed therein in the downtrack direction having the side gap layer positioned therein, the side gap is non-conformal in shape, and a position of the side shield relative to a position of the main pole is characterized as being self-aligned.