Dual-Coil HAMR Recording Head for Field Angle Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In heat-assisted magnetic recording (HAMR) systems, achieving faster saturation and optimal field angle at the recording point while maintaining efficient flux closure and optical path integrity is challenging due to the asymmetrical magnetic system design, which affects rise time and saturation characteristics.
Innovation Solution
A recording head with a first coil inducing flux in a write pole and a second coil proximate a shield to control the field angle, allowing for coordinated current application to achieve desired magnetic field characteristics, including faster saturation and improved field angle, by using a dual-coil configuration that can be strategically positioned and coated for optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single coil is used to induce flux in the write pole, then the structure is simple, but the field angle control and saturation efficiency are insufficient
Solution Approach 1:
The single coil structure is divided into two separate coils: a first coil for inducing flux in the write pole and a second coil for inducing flux in the shield. This segmentation allows independent control of each coil's current, enabling precise field angle control and improved saturation efficiency without excessive structural complexity.
Solution Approach 2:
The system employs dynamic current control where the first and second coils can receive different current waveforms with varying amplitudes, phases, and timing. This dynamic control enables real-time adjustment of the write field angle and saturation characteristics to optimize recording performance.
2Manufacturing precision
If the second coil is positioned close to the shield, then field angle control is improved, but the optical path may be affected
Solution Approach 1:
The second coil is positioned specifically on the shield structure at a location that optimizes field angle control while maintaining sufficient distance from the optical path. The coil's placement exploits the local magnetic properties of the shield to achieve effective flux induction without interfering with light transmission through the near-field transducer.
Solution Approach 2:
The shield acts as an intermediary magnetic structure that the second coil magnetizes to control the write field angle. By inducing flux in the shield rather than directly in the write pole, the system achieves precise field angle control while keeping the coil positioned away from the critical optical path, thus avoiding direct optical interference.
3Productivity
If coordinated current application to both coils is used, then saturation efficiency and rise time are improved, but the control complexity increases
Solution Approach 1:
The control system incorporates feedback mechanisms that monitor the magnetic field characteristics and adjust the current waveforms applied to the first and second coils in real-time. This feedback control enables optimized saturation efficiency and rise time by dynamically tuning the coil currents based on actual system performance and recording conditions.
Solution Approach 2:
The system controls saturation efficiency and rise time by changing key parameters of the current waveforms applied to the coils, including amplitude ratios, phase differences, and timing sequences. By adjusting these electrical parameters, the system optimizes magnetic field generation without requiring complex mechanical or structural modifications.
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 dual-coil configuration enhances rise time and saturation efficiency, dynamically controlling the write field angle and maintaining optical efficiency by coordinating current application and using reflective coatings, thereby improving data recording quality in HAMR systems.
Implementation Method 1
A first coil induces a first flux in the write pole
Implementation Method 2
A second coil is proximate the shield and induces a second flux in the shield that controls a field angle of the first flux
Implementation Method 3
heat-assisted magnetic recording (HAMR) systems
Data Source
AI summary
A recording head has a near-field transducer at a media-facing surface of the recording head and a write pole on a first side of the near field transducer. A first coil induces a first flux in the write pole. The recording head includes a shield on a second side of the near-field transducer that faces away from the first side. A second coil is proximate the shield and induces a second flux in the shield that controls a field angle of the first flux.