Notched HAMR Write Pole for Better Write Field Perpendicularity
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Solution Overview
Problem
Existing heat assisted magnetic recording (HAMR) technologies face challenges in maintaining optimal write field angle perpendicularity, which affects areal density capability (ADC) as the angle deviates from perpendicular, leading to degraded performance.
Innovation Solution
Incorporating a notch in the write pole at its leading edge, filled with a non-magnetic metal, and spacing it from a near field transducer (NFT) with an insulating material, adjusts the write field angle to enhance perpendicularity, thereby improving ADC.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional write pole structure is used in HAMR, then the device structure is simple, but the write field angle deviates from perpendicular leading to degraded areal density capability
Solution Approach 1:
The write pole is segmented by introducing a notch that divides the pole structure into distinct regions. This segmentation allows independent optimization of different pole sections to control magnetic field distribution and achieve better perpendicularity without requiring complete redesign of the entire pole structure.
Solution Approach 2:
Different materials are applied to different regions of the write pole: a first material (e.g., CoFeB) is deposited on the pole face while a second material (e.g., CoFe) is deposited in the notch region. This local differentiation of material properties enables precise control of the write field angle perpendicularity at critical locations without affecting the entire pole structure.
2Force
If the write field magnitude is increased to improve writing capability, then the write strength is enhanced, but the write field angle deviation from perpendicular increases leading to degraded ADC
Solution Approach 1:
The invention changes material parameters (composition, thickness) in the notch region to decouple the relationship between write field magnitude and angle perpendicularity. By adjusting the magnetic properties of materials in the notch, the system can maintain optimal perpendicularity across a broader range of write field magnitudes, allowing higher field strength without proportional degradation of angular precision.
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 notch configuration enhances write field perpendicularity, resulting in improved areal density capability (ADC) by optimizing the alignment between the write pole and media surface, particularly at higher write field magnitudes.
Implementation Method 1
a write pole extending to a media-facing surface and having a leading edge and a trailing edge relative to movement of a storage media in a down-track direction
Implementation Method 2
A near field transducer (NFT) is in essence a nanoscale "antenna" for directing plasmons at the media surface, often employed in heat assisted magnetic recording (HAMR)
Implementation Method 3
HAMR refers to the concept of locally heating the recording media to reduce the coercivity, thereby allowing the applied magnetic field to more easily direct the magnetization of the media during temporary magnetic softening
Data Source
AI summary
Described is a recording head that includes a notched write pole to enhance perpendicularity of the write pole field. The write pole notch is formed at the media-facing surface and the leading edge of the write pole. The write pole notch is filled with a non-magnetic metal. The recording head further includes a near field transducer located in front of the leading edge of the write pole and having a portion extending to the media-facing surface that is spaced apart from the notch, thereby forming a gap between the near field transducer and the notch.