Magnetic Head Shield Segmentation for Perpendicular Recording
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic heads for perpendicular magnetic recording systems face challenges in preventing adjacent track erase due to skew, where signals on adjacent tracks are erased or attenuated during writing, and existing shield configurations are inefficient in capturing magnetic flux and maintaining close proximity between the main pole and return poles.
Innovation Solution
A magnetic head design featuring a shield with a bottom shield, side shields, and a top shield made of magnetic material, along with a gap part and return path sections, which allows for effective capture of magnetic flux and close proximity between the main pole and the bottom shield, enhancing the shield's function and preventing adjacent track erase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a shield is provided around the main pole to prevent adjacent track erase, then the shield function is improved, but the distance between the main pole and the return pole increases, reducing magnetic coupling efficiency
Solution Approach 1:
The shield is divided into multiple segments: a bottom shield, side shields, and a top shield. This segmentation allows the shield to effectively capture magnetic flux while maintaining appropriate distances from the main pole and return poles, resolving the contradiction between shield functionality and magnetic coupling efficiency.
Solution Approach 2:
The shield extends in multiple dimensions (bottom, sides, and top) to create a comprehensive magnetic flux capture structure. This three-dimensional configuration allows the shield to be effective in preventing adjacent track erase while maintaining optimal distances from other components through spatial distribution.
2Quantity of substance
If the track width is reduced to increase recording density, then the recording density is improved, but the write characteristics such as overwrite property deteriorate
Solution Approach 1:
The main pole is designed with non-uniform width along its length, being wider at the bottom and narrower at the top. This local variation in geometry allows the pole to maintain a small track width for high recording density while providing sufficient magnetic flux generation area for good write characteristics.
Solution Approach 2:
The geometric parameters of the main pole are optimized, particularly the width variation along the pole length and the gap between the main pole and return pole. These parameter changes enable simultaneous optimization of both recording density and write characteristics.
3Reliability
If the main pole end face width is reduced to prevent adjacent track erase, then the adjacent track erase is prevented, but the magnetic flux generation capability decreases
Solution Approach 1:
The main pole is designed with a wider bottom portion that preliminarily generates sufficient magnetic flux before the flux reaches the narrower top portion. This preliminary flux generation ensures that even with a narrow end face width for preventing adjacent track erase, the overall magnetic flux generation capability is maintained.
Solution Approach 2:
The main pole geometry transitions dynamically from wide at the bottom to narrow at the top, allowing the pole to adapt its effective width at different heights. This dynamic geometry enables the pole to provide sufficient flux generation area where needed while maintaining a narrow profile at the medium-facing surface to prevent adjacent track erase.
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 design effectively captures magnetic flux and prevents adjacent track erase by ensuring the shield can direct magnetic fields correctly, thereby improving recording density and write characteristics.
Implementation Method 1
a coil that produces a magnetic field corresponding to data to be written on the recording medium
Implementation Method 2
a main pole that has an end face located in the medium facing surface, allows a magnetic flux corresponding to the magnetic field produced by the coil to pass, and produces a write magnetic field for writing the data on the recording medium
Implementation Method 3
provide a shield having an end face that is located in the medium facing surface to wrap around the end face of the main pole... These techniques allow capturing a magnetic flux that is produced from the end face of the main pole and expands in the track width direction
Data Source
AI summary
A magnetic head includes a shield, and first and second return path sections. The shield has an end face that is located in a medium facing surface to wrap around an end face of a main pole. The shield includes a bottom shield, two side shields, and a top shield. The first return path section includes a yoke layer, and first and second coupling layers that magnetically couple the bottom shield and the yoke layer to each other. The first coupling layer is magnetically connected to the bottom shield. The second coupling layer magnetically couples the first coupling layer to the yoke layer. No end faces of the second coupling layer are exposed in the medium facing surface. The second return path section magnetically couples the top shield and the main pole to each other.