Command Clustering for Magnetic Storage Head Life Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The use of Thermal Fly-Height Control (TFC) in data storage devices reduces the usable life and reliability of heads due to increased heat application and decreased fly-height, leading to material degradation and increased friction or wear, as well as lubricant accumulation that interferes with data reading and writing.
Innovation Solution
Implementing command clustering to reduce the time the fly-height heater is powered on by grouping read and write commands, allowing the TFC timer to be applied on a per-cluster basis instead of per-command basis, and disabling clustering at high command rates to prevent excessive heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Thermal Fly-Height Control (TFC) with fly-height heater is used to maintain consistent fly-height, then reading and writing accuracy is improved, but slider or head material degradation accelerates and usable life reduces
Solution Approach 1:
The fly-height heater is activated before data writing operations to preheat the slider and establish the desired fly-height position. This preliminary heating action allows the slider to reach its optimal thermal state before actual data operations begin, reducing the need for continuous high-power heating during critical operations and thereby extending head life while maintaining reading and writing accuracy
2Manufacturing precision
If fly-height heater is activated to maintain consistent fly-height during writing, then writing accuracy is improved, but heat-induced material degradation increases
Solution Approach 1:
The fly-height heater operates in periodic cycles rather than continuously, being activated only during specific operations such as before writing operations or when fly-height adjustments are needed. This periodic activation pattern reduces cumulative heat exposure and material degradation while maintaining writing accuracy when the heater is active, balancing precision requirements with thermal management
3Quantity of substance
If fly-height is lowered to increase storage density, then areal density is improved, but friction and wear on slider or head increase
Solution Approach 1:
The system dynamically adjusts the fly-height parameter based on operational requirements by controlling the fly-height heater. When high areal density is needed, the heater activates to thermally expand the slider and lower the fly-height, increasing storage capacity. When friction and wear become concerns, the heater reduces power or shuts off, allowing the fly-height to increase and reducing contact with the disk surface, thus balancing storage density with wear prevention
4Stability of the object's composition
If fly-height heater is used continuously to maintain fly-height, then fly-height consistency is improved, but lubricant accumulation on slider or head increases
Solution Approach 1:
The fly-height heater operates periodically rather than continuously, activating only when fly-height adjustments are required for specific operations. These periodic heating cycles maintain sufficient fly-height consistency for accurate data operations while creating intervals where the heater is off, allowing reduced lubricant accumulation compared to continuous operation, thus balancing fly-height stability with lubricant management
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 approach extends the life of the sliders and heads by minimizing heater usage, reducing material degradation and lubricant accumulation, while maintaining consistent fly-height for accurate data storage and retrieval.
Implementation Method 1
a fly-height heater on the slider that causes a bottom surface of the slider to expand or protrude closer to the disk surface when the heater is on
Implementation Method 2
the fly-height can change when a write current used to write data on the disk causes part of a slider including the head to heat up and expand or protrude toward the disk
Data Source
AI summary
A plurality of commands is received from a host to perform at least one of reading data and writing data on a magnetic storage media of a Data Storage Device (DSD). The plurality of commands is clustered for performance based at least in part on a timing control of a fly-height heater of the DSD that is configured to adjust a flying height of a head of the DSD while the head is flying over the magnetic storage media. A cluster of commands is performed including the plurality of commands by controlling the head to perform at least one of reading and writing data on the magnetic storage media for the cluster of commands.