Perpendicular Magnetic Recording Medium Shingle Recording Density
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Solution Overview
Problem
Current perpendicular magnetic recording technologies face challenges in achieving high track recording density while maintaining a sufficient signal-to-noise ratio, particularly with the shingle recording type, where the recording head's magnetic field density is compromised by narrow track widths.
Innovation Solution
A perpendicular magnetic recording medium with a laminated film structure, including a soft magnetic ground layer, where the thickness of the soft magnetic ground layer is optimized based on the core width of the magnetic head and track pitch, allowing for a thinner layer that ensures sufficient overwrite characteristics and reduced track edge curvature, thereby enhancing Spi-SNR.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the track width is decreased to improve track recording density, then track recording density increases, but recording magnetic field density decreases leading to insufficient S/N ratio
Solution Approach 1:
The patent transitions from conventional longitudinal magnetic recording to perpendicular magnetic recording, changing the dimension of magnetization from in-plane to out-of-plane. This dimensional change enables higher recording density while maintaining adequate signal quality through the vertical magnetic field configuration
Solution Approach 2:
The patent optimizes the thickness of the soft magnetic ground layer as a key parameter to achieve the desired balance between track recording density and S/N ratio. By controlling the soft magnetic ground layer thickness, the recording medium achieves improved perpendicular magnetic recording characteristics
2Reliability
If a thick soft magnetic ground layer is used to ensure overwrite characteristics, then overwrite characteristics improve, but track edge curvature increases degrading Spi-SNR
Solution Approach 1:
The patent optimizes the soft magnetic ground layer thickness to a specific range that simultaneously satisfies both overwrite characteristics and track edge curvature requirements. This parameter optimization resolves the contradiction by finding the optimal thickness value
Solution Approach 2:
The patent employs a composite layered structure consisting of the soft magnetic ground layer, recording layer, and other functional layers. This composite structure enables the system to achieve both sufficient overwrite characteristics and reduced track edge curvature through the synergistic interaction of different layers
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 configuration enables improved recording and reproduction characteristics, maintaining sufficient overwrite characteristics and increasing recording density by suppressing bit curvature and noise, making the medium suitable for shingle recording type applications.
Implementation Method 1
a soft magnetic ground layer and a recording layer formed on a base, the soft magnetic ground layer having a thickness found from a core width of a magnetic head for recording and reproduction
Data Source
AI summary
[Problem] A perpendicular magnetic recording medium and a magnetic disk device that are suitable for a shingle recording type are provided.[Solution] The perpendicular magnetic recording medium of the present invention is a perpendicular magnetic recording medium for a shingle recording type having a laminated film including a soft magnetic layer 13 and a main recording layer 16 formed on base 11, the soft magnetic layer 13 having a thickness found from a core width of a magnetic head for recording and reproduction with respect to the perpendicular magnetic recording medium and a track pitch narrower than the core width.