Thermally Assisted Recording Head Protrusion Control
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Solution Overview
Problem
Conventional thin film magnetic write heads with thermal fly height control face challenges in achieving rapid thermal response due to the location and thermal mass of resistive heaters, leading to transient delays and potential thermal oscillations, especially when combined with thermally assisted recording heat sources.
Innovation Solution
The implementation of a method using a near field optical source with a conductive metal film and optical waveguides to provide a higher optical power level initially, followed by a lower level, in conjunction with resistive heating, to rapidly alter the air bearing surface protrusion for faster thermal fly height control during data writing, potentially replacing or supplementing resistive heater pulses for improved response times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If resistive heaters are used for thermal fly height control, then the head can be heated to adjust fly height, but transient delays and thermal oscillations occur due to the location and thermal mass of the heaters
Solution Approach 1:
The patent applies preliminary action by providing a first optical power level to the TAR system before the write operation begins (between time t1 and t2), pre-heating the head to reduce the transient delay when thermal response is needed during subsequent write operations
Solution Approach 2:
The patent uses periodic action by alternating between a first optical power level (before write) and a second optical power level (during write, between t2 and t3), creating a controlled thermal cycling pattern that optimizes both response speed and stability
2Speed
If higher optical power is provided to the TAR system during write operations, then faster thermal transitions are achieved, but media surface overheating may occur
Solution Approach 1:
The patent applies local quality by providing different optical power levels at different time intervals: a first power level before write and a lower second power level during write (between t2 and t3), optimizing thermal response locally in time to prevent media overheating while achieving fast transitions
Solution Approach 2:
The patent changes the optical power parameter dynamically - switching from a first optical power level to a second optical power level (where the first is greater than the second) - to balance the need for fast thermal transitions with the constraint of preventing media surface overheating
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 enables faster thermal transitions and reduced fly height adjustments, enhancing the write head's ability to quickly reach data zones while minimizing media surface overheating and maintaining reliable data storage.
Implementation Method 1
control of the light energy is operable to alter protrusion of the thin film magnetic head structure at the air bearing surface
Implementation Method 2
a second optical waveguide operable to illuminate a light absorption structure embedded within said thin film magnetic head
Implementation Method 3
This is done by thermally deforming the head, via thermal expansion, in a controlled manner to fine tune the actual position of the ABS (air bearing surface) relative to the media surface
Data Source
AI summary
Methods and structures for improving fly height control for thin film write heads utilized in thermally assisted recording are disclosed. Methods include the use of the TAR near field light source to provide a preheating pulse to improve the transient response when moving from one fly height to another prior to writing data. Methods and structures having an additional auxiliary optical heating source to avoid media overheating and replacement of embedded resistive heaters are also disclosed.