Magnetic Recording Medium Servo Pattern via Microwave-Assisted Recording
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Solution Overview
Problem
In magnetic recording media, the narrow width of data tracks leads to difficulties in accurately following the tracks during data recording and reproduction, resulting in errors, and the formation of servo patterns to address this issue faces challenges with thermal stability and writing easiness due to the high coercivity required for high-density recording.
Innovation Solution
A manufacturing method for a coating type magnetic recording medium with a magnetic layer containing ferromagnetic powder and a binding agent, where the natural ferromagnetic resonance frequency is equal to or greater than 30.0 GHz, utilizing microwave-assisted recording to form servo patterns, thereby improving writing easiness and thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the particle size of ferromagnetic powder is decreased to achieve high-density recording, then recording density is improved, but thermal stability of magnetization decreases due to thermal fluctuation
Solution Approach 1:
The patent changes the parameter of natural ferromagnetic resonance frequency to be equal to or greater than 30.0 GHz, which corresponds to changing the magnetic properties of the ferromagnetic powder. This parameter change allows achieving both high recording density and sufficient thermal stability by selecting ferromagnetic powder with appropriate resonance characteristics that balance particle size effects with thermal fluctuation resistance.
2Stability of the object's composition
If the anisotropy constant Ku is increased to improve thermal stability, then thermal stability of magnetization is improved, but coercivity Hc increases and writing easiness decreases
Solution Approach 1:
The patent resolves this contradiction by changing to a different parameter domain - using ferromagnetic powder with natural ferromagnetic resonance frequency of 30.0 GHz or higher. This resonance frequency condition provides a new criterion for selecting powder that simultaneously achieves adequate thermal stability and acceptable writing characteristics, avoiding the direct trade-off between Ku and Hc by operating at higher resonance frequencies where the relationship between these parameters changes.
3Reliability
If strong external magnetic field is applied to record data information, then recording capability is improved, but writing easiness decreases due to high coercivity requirement
Solution Approach 1:
The patent changes the magnetic parameter of the ferromagnetic powder to have natural ferromagnetic resonance frequency of 30.0 GHz or higher. This parameter change modifies the magnetic response characteristics, allowing the system to achieve reliable recording with more manageable magnetic field requirements, thereby improving writing ease while maintaining recording capability.
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 method enhances the accuracy of head tracking and retention of data information by improving the writing easiness and thermal stability of servo patterns on the magnetic recording medium, allowing for precise data recording and reproduction.
Implementation Method 1
the magnetic layer shows a natural ferromagnetic resonance frequency equal to or greater than 30.0 GHz
Implementation Method 2
forming a servo pattern on the magnetic layer by microwave-assisted recording
Data Source
AI summary
Provided is a manufacturing method of a magnetic recording medium, in which the magnetic recording medium includes a magnetic layer including ferromagnetic powder and a binding agent on a non-magnetic support, and the magnetic layer shows a natural ferromagnetic resonance frequency equal to or greater than 30.0 GHz, the method including: forming a servo pattern on the magnetic layer by microwave-assisted recording.