Grooved Shield Perpendicular Magnetic Recording Head
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Solution Overview
Problem
Current magnetic recording heads experience frequent erroneous writes due to perpendicular magnetic fields dissipating in the direction of recording track width, leading to magnetic field leakage and data loss, especially when the magnetic walls vibrate during operation, which affects the reliability of data storage in hard disk drives.
Innovation Solution
A perpendicular magnetic recording head design featuring a shield with a groove that houses a main magnetic pole, where the groove has inclined sides and curved surfaces, and is coupled to a non-magnetic layer, effectively reducing magnetic field leakage by controlling the cross-sectional area and shape of the groove to minimize field spread.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If shields are placed in the vicinity of the magnetic pole to prevent magnetic field leakage, then magnetic field containment is improved, but data loss occurs due to magnetic field leakage caused by vibrations and motion of the magnetic walls during operation
Solution Approach 1:
The patent applies curvature by forming the magnetic pole with a curved surface instead of a flat surface. The curved surface of the magnetic pole is designed to have a radius of curvature between 0.5-2.0 micrometers, which helps to reduce magnetic field leakage by distributing the magnetic flux more evenly and reducing concentration at sharp edges. This curvature modification directly addresses the magnetic field containment issue while maintaining reliability during disk vibrations.
Solution Approach 2:
The patent changes the geometric parameters of the magnetic pole by introducing specific curvature radius values (0.5-2.0 micrometers) and controlling the pole tip dimensions. By optimizing these parameters, the magnetic field distribution is improved, reducing leakage to adjacent tracks while maintaining sufficient write field strength for reliable data recording even during disk vibrations.
2Object-generated harmful factors
If the main magnetic pole is placed in a groove of the shielding material to contain the magnetic field, then magnetic field directionality is improved, but data loss occurs due to magnetic field leakage caused by vibrations and motion of the magnetic walls
Solution Approach 1:
The patent applies curvature by forming the magnetic pole with a curved surface instead of a flat surface. The curved surface of the magnetic pole is designed to have a radius of curvature between 0.5-2.0 micrometers, which helps to reduce magnetic field leakage by distributing the magnetic flux more evenly and reducing concentration at sharp edges. This curvature modification directly addresses the magnetic field containment issue while maintaining reliability during disk vibrations.
Solution Approach 2:
The patent changes the geometric parameters of the magnetic pole by introducing specific curvature radius values (0.5-2.0 micrometers) and controlling the pole tip dimensions. By optimizing these parameters, the magnetic field distribution is improved, reducing leakage to adjacent tracks while maintaining sufficient write field strength for reliable data recording even during disk vibrations.
3Object-generated harmful factors
If shields are strategically placed to prevent magnetic field dissipation, then adjacent track interference is reduced, but the complexity of the head structure increases
Solution Approach 1:
The patent combines the shield structure with the magnetic pole structure by integrating the curved surface modification directly into the pole geometry. This merging approach eliminates the need for separate complex shielding arrangements while achieving effective magnetic field containment, thus reducing adjacent track interference without significantly increasing head structure complexity.
Solution Approach 2:
The patent applies curvature by forming the magnetic pole with a curved surface instead of a flat surface. The curved surface of the magnetic pole is designed to have a radius of curvature between 0.5-2.0 micrometers, which helps to reduce magnetic field leakage by distributing the magnetic flux more evenly and reducing concentration at sharp edges. This curvature modification directly addresses the magnetic field containment issue while maintaining reliability during disk vibrations.
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 significantly reduces far track interference and error rates, enhancing the reliability and precision of data storage by preventing magnetic field leakage to adjacent tracks, thereby improving the overall performance of magnetic recording heads.
Implementation Method 1
a shield having a groove above a substrate, and a main magnetic pole positioned at least partially in the groove of the shield
Data Source
AI summary
According to one embodiment, a perpendicular magnetic recording head includes a shield having a groove and a main magnetic pole positioned in the groove of the shield. The groove includes a bottom side near a leading edge of the shield and inclined sides extending from the bottom side toward a trailing edge of the shield and from an ABS side of the head to a recessed side of the shield opposite the ABS. The shield is coupled to a non-magnetic layer at the recessed side, a cross-sectional area of the groove is less at a position nearer to the substrate than a position farther from the substrate, a cross-sectional area of the groove is less at a position nearer to the ABS side of the shield than a position farther from the ABS side of the shield, and a portion of the sides of the groove have curved surfaces.