Magnetic Recording Head Notch Shield for Shingled Track Writing
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Solution Overview
Problem
Conventional magnetic recording heads have a large radius of the magnetic field at the trailing corner, which affects the data density and reliability of shingled track writing in magnetic hard disk drives.
Innovation Solution
A magnetic recording head with a notch in the trailing corner of the Wrap-Around Shield (WAS) is designed to modify the magnetic field profile, reducing the radius and improving field uniformity across the track.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional magnetic recording head design is used, then the structure is simple and easy to manufacture, but the radius of the magnetic field at the trailing corner is large, reducing data density and reliability
Solution Approach 1:
The wrap-around shield is segmented by introducing notches at the trailing corner, dividing the continuous shield structure into sections that independently control the magnetic field. This segmentation allows precise control of the magnetic field radius at the trailing corner while maintaining overall shield functionality.
Solution Approach 2:
The notches are placed specifically at the trailing corner where precise magnetic field control is most critical for shingled track writing. This local modification optimizes the magnetic field profile exactly where needed without unnecessarily complicating the entire shield structure.
2Quantity of substance
If the magnetic field radius at the trailing corner is reduced for better data density, then data storage capacity increases, but the shield structure becomes more complex
Solution Approach 1:
The shield is segmented with notches that create distinct magnetic field zones, enabling reduced field radius at the trailing corner to improve track overlap precision and data storage capacity while keeping the added complexity minimal and localized.
Solution Approach 2:
The notch geometry (depth, width, position) is optimized to achieve the desired magnetic field radius reduction. By carefully controlling these parameters, the patent achieves smaller field radius for higher data density without excessive structural complexity.
3Ease of manufacture
If a larger shield gap is used, then manufacturing is easier and tolerance is more forgiving, but magnetic field uniformity across the track deteriorates
Solution Approach 1:
The notches create localized magnetic field control zones at the trailing corner, allowing the shield gaps to remain relatively large for ease of manufacture while maintaining field uniformity through the notch-induced field shaping in the critical region.
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 modified magnetic field profile enhances data density and reliability by providing a sharper field corner, allowing for more precise magnetization and increased data storage capacity.
Implementation Method 1
As the disk rotates under the read/write head, the write head generates a varying magnetic field to create transitions in the magnetic material of the disk
Implementation Method 2
A strong magnetic field emerges from the write pole tip in a direction perpendicular to the magnetic disk surface and passes through the top layer of the disk, magnetizing the magnetically hard material of the top layer
Implementation Method 3
The read/write heads are biased toward the surface of the disk and when the disk rotates, the head floats on a cushion of the air that is moving with the disk. As this layer of air separates the moving disk surface from the relatively stationary read/write head
Data Source
AI summary
A magnetic recording head including a write pole and a shield. The write pole has a pole tip face that is parallel to the air bearing surface of the magnetic recording head, a leading surface having a leading edge at the pole face, a first side surface having a first side edge at the pole face, a second side surface having a second side edge at the pole face, and a trailing surface having a trailing edge at the pole face. The shield surrounds the first side surface, the trailing surface, and the second side surface of the write pole tip, and is separated from the first side surface of the write pole tip by a first side gap, from the trailing surface of the write pole tip by a trailing gap, and from the second side surface of the write pole tip by a second side gap. There is a notch formed in the inner wall of the shield adjacent to the corner of the write pole tip formed by one side surface and the trailing surface of the write pole tip.