Magnetic Recording Head Notched Shield Design
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Solution Overview
Problem
The reduction in size of magnetic recording sensors leads to a significant drop in on-track field, requiring low coercivity media and limiting areal density improvement, as side shields reduce fringe field but also on-track field, necessitating smaller coercivity media to maintain acceptable writing.
Innovation Solution
A magnetic recording head design featuring notched shields with a recess in the front shield adjacent to the trailing edge of the main pole, which extends laterally and minimizes magnetic field loss while maximizing recording density by maintaining a larger on-track field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If side shields are used to reduce fringe field, then WPE is reduced, but on-track field is also reduced
Solution Approach 1:
The front shield is segmented by adding a recess that divides the shield structure into distinct regions. This segmentation allows different portions of the shield to perform different functions: the main body continues to suppress fringe field, while the recessed area allows selective magnetic flux passage to preserve on-track field strength.
Solution Approach 2:
The recess in the front shield creates a local variation in magnetic shield properties. By introducing a recess at a specific location (adjacent to the trailing edge), the design achieves different magnetic flux characteristics in different regions: strong shielding in most areas and controlled flux passage in the recessed area.
2Productivity
If sensor size is decreased to increase recording density, then areal density is improved, but on-track field drops significantly
Solution Approach 1:
The recess modification changes the geometric parameters of the front shield, which in turn modifies the magnetic field distribution. This parameter change allows the system to maintain stronger on-track field while supporting smaller sensor dimensions for higher areal density.
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 allows for higher areal density recording by reducing WPE while minimizing on-track field loss, enabling improved recording capabilities.
Implementation Method 1
A recess extends into the front shield adjacent to the trailing edge, and parallel to the trailing edge. The recess extends laterally away from the main pole and into the front shield a distance greater than the first side shield gap or second side shield gap.
Data Source
AI summary
A magnetic recording head includes a magnetic recording write element including a main pole having a leading edge and an opposing trailing edge and a first side surface and a second side surface separating the leading edge from the trailing edge. A first side shield gap separates a first side shield from the first side of the main pole and a second side shield gap separates the second side shield from the second side of the main pole. A front magnetic shield is separated from the main pole trailing edge by a front shield gap. A recess extends into the front shield adjacent to the trailing edge, and parallel to the trailing edge. The recess extends laterally away from the main pole and into the front shield a distance greater than the first side shield gap or second side shield gap.