Asymmetrical Side Gap in Wrap-Around Trailing Shield
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic write heads face challenges in minimizing adjacent track interference and write field loss, particularly due to the tradeoff in side gap sizing which affects both interference and write field gradient.
Innovation Solution
A magnetic write head design featuring a wrap-around trailing shield with asymmetrical side gaps, where one side gap is significantly larger than the other, providing enhanced protection against adjacent track interference and write field loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a symmetrical side gap design is used in the trailing shield, then manufacturing simplicity is maintained, but adjacent track interference cannot be adequately minimized on both sides
Solution Approach 1:
The patent applies asymmetry by configuring the trailing shield with different side gap dimensions on opposite sides of the write pole. Specifically, one side gap is made larger than the other, allowing each side to be optimized for its specific function: the larger side gap reduces adjacent track interference on that side, while the smaller side gap maintains write field strength. This asymmetric configuration directly resolves the contradiction by sacrificing symmetrical simplicity to achieve superior interference mitigation.
Solution Approach 2:
The patent implements local quality by tailoring the side gap characteristics to the specific requirements of each side of the write head. Rather than applying a uniform gap design, the trailing shield features differentiated gap dimensions positioned at specific locations. This allows each local region to have optimized properties: one side prioritizes interference reduction with a larger gap, while the other side prioritizes field retention with a smaller gap, thereby resolving the contradiction between interference protection and device complexity.
2Object-affected harmful factors
If a larger side gap is used, then adjacent track interference is reduced, but write field loss increases
Solution Approach 1:
The asymmetric side gap configuration allows the write head to resolve the contradiction between interference reduction and field loss by applying different gap sizes on different sides. The larger side gap effectively reduces adjacent track interference on that side, while the smaller side gap prevents excessive write field loss. This spatial differentiation enables each side to optimize for its primary function without compromising the other side's performance.
Solution Approach 2:
The patent applies local quality by positioning specific gap characteristics at specific locations around the write pole. The larger gap is placed on the side where adjacent track interference is the primary concern, while the smaller gap is placed on the side where write field retention is more critical. This localized optimization allows the system to simultaneously address both interference reduction and field loss prevention in their respective regions.
3Strength
If a smaller side gap is used, then write field strength is maintained, but adjacent track interference increases
Solution Approach 1:
The asymmetric trailing shield design resolves this contradiction by implementing different gap sizes on opposite sides of the write pole. The smaller side gap maintains write field strength on its side, while the larger side gap reduces adjacent track interference on the other side. This asymmetric configuration allows the system to simultaneously satisfy both requirements in different spatial locations, eliminating the need to choose one compromise solution.
Solution Approach 2:
The patent implements local quality by optimizing the side gap characteristics for the specific functional requirements of each side. The smaller gap is positioned where write field strength is the priority, while the larger gap is positioned where interference reduction is more important. This localized functional differentiation allows each region to achieve its primary objective without compromising the other side's performance.
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 asymmetrical side gap design effectively reduces adjacent track interference on one side while minimizing write field loss on the other, optimizing both interference protection and write field strength.
Implementation Method 1
a wrap-around magnetic trailing shield separated from the write pole by a first nonmagnetic side gap at a first side of the write pole and by a second nonmagnetic side gap at a second side of the write pole
Implementation Method 2
Current conducted to the coil layer induces a magnetic flux in the pole pieces which causes a magnetic field to fringe out at a write gap at the ABS
Implementation Method 3
Magnetoresistive sensors such as GMR or TMR sensors are employed for sensing magnetic fields from the rotating magnetic disk
Implementation Method 4
a portion of the conduction electrons is scattered by the interfaces of the spacer layer with each of the pinned and free layers. When the magnetizations of the pinned and free layers are parallel with respect to one another, scattering is minimal and when the magnetizations of the pinned and free layer are antiparallel, scattering is maximized
Data Source
AI summary
A magnetic write head having a magnetic write pole with a wrap around magnetic trailing shield. The wrap around magnetic trailing shield is separated by a first non-magnetic side gap at a first side of the write pole and by a second non-magnetic side gap at a second side of the write pole. The first second non-magnetic side gap is larger than the first non-magnetic side gap and is preferably at least twice the thickness of the first non-magnetic side gap. This design provides additional protection adjacent track interference at one side of the write pole and additional protection against magnetic write field loss at the other side of the write pole.