HAMR Head Parameter Tuning for SMR Band Start Write Stability
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Solution Overview
Problem
In heat-assisted magnetic recording, the buildup of components from the magnetic film adhering to the near-field transducer due to temperature rise degrades write performance, especially in areas with fluctuating flying heights, leading to read errors.
Innovation Solution
Adjusting parameters such as bit density, parity number, laser current, write current, TPI, and flying height in specific areas like the start of the shingled magnetic recording (SMR) band and areas storing non-user data to improve write characteristics and prevent read errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the flying height is lowered to scrape off buildup, then the buildup is removed, but the write performance is degraded until the buildup is generated again
Solution Approach 1:
The patent applies preliminary action by adjusting parameters (bit density, parity number, laser current, write current, TPI, flying height) in advance for specific areas (start area of SMR band and areas storing non-user data) where buildup is more likely to occur. This preventive adjustment ensures write performance is maintained before buildup problems arise, rather than reacting after performance degrades.
2Reliability
If the flying height is increased to prevent buildup scraping, then the buildup is formed again by lubricant filling the head-media interface
Solution Approach 1:
The patent applies local quality by making parameter adjustments specific to particular areas of the magnetic disk - namely the start area of the shingled magnetic recording band and areas storing non-user data. These locations are identified as having higher susceptibility to buildup, so localized parameter optimization is applied only where needed, rather than uniformly across the entire disk surface.
3Reliability
If parameters are adjusted in specific areas to improve write characteristics, then write performance is improved in those areas, but the overall system complexity increases
Solution Approach 1:
The patent applies local quality by making parameter adjustments specific to particular areas of the magnetic disk - namely the start area of the shingled magnetic recording band and areas storing non-user data. These locations are identified as having higher susceptibility to buildup, so localized parameter optimization is applied only where needed, rather than uniformly across the entire disk surface.
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
Ensures sufficient write characteristics and prevents read errors by applying corrections in advance, maintaining good performance in areas prone to buildup issues.
Implementation Method 1
the temperature of a magnetic disk is raised for recording by laser
Implementation Method 2
a near-field transducer that generates near-field light
Data Source
AI summary
According to one embodiment, an adjustment method of a heat-assisted magnetic recording and reproduction device including a magnetic recording head and a heat-assisted magnetic recording medium, in which write characteristics are improved in a start area of a shingled magnetic recording band and in each area storing information other than user data.