Perpendicular Magnetic Recording Write Head Wrap-Around Shield
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Solution Overview
Problem
Conventional perpendicular magnetic recording (PMR) heads suffer from stray side fields causing side erasure of adjacent tracks and increased magnetic track width, which limits the achievement of reduced track pitch required for ultrahigh density recording due to uniform throat height and gap thickness in existing fabrication methods.
Innovation Solution
A method for fabricating a PMR head with a trapezoidal pole, where the side gap and side shield are deposited separately from the top gap and top shield, allowing independent configuration of their widths and thicknesses, and a planarization step is performed to expose the pole, enabling better edge definition and field control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If side shields are added to conventional PMR heads to reduce stray side fields, then side erasure is reduced, but the fabrication complexity increases due to uniform throat height requirements
Solution Approach 1:
The shield structure is segmented into distinct components: top shields with uniform throat height and side shields with variable throat heights. This segmentation allows each component to be optimized independently, reducing side erasure through proper side shield configuration while maintaining fabrication simplicity through standardized top shield geometry.
Solution Approach 2:
Different regions of the shield structure are given different properties: the top shields maintain uniform throat height for ease of fabrication, while the side shields are configured with variable throat heights tailored to specific positional requirements. This local differentiation optimizes both fabrication efficiency and side erasure reduction performance.
2Ease of manufacture
If uniform throat height is used in shield fabrication, then manufacturing is simplified, but side erasure control is compromised
Solution Approach 1:
The shield is divided into top shields (uniform throat height for easy manufacturing) and side shields (variable throat height for optimized side erasure control). This segmentation resolves the contradiction by assigning different geometric requirements to different functional regions.
Solution Approach 2:
Uniform throat height is applied locally to top shields where fabrication simplicity is prioritized, while variable throat height is applied locally to side shields where side erasure control is critical. This localized application of different geometric properties optimizes both manufacturing ease and performance.
3Object-affected harmful factors
If side shields with variable throat heights are implemented, then side erasure is reduced, but device complexity increases
Solution Approach 1:
The complex variable throat height requirement is segmented and applied only to side shields, while top shields maintain simple uniform geometry. This segmentation confines the complexity to where it is most needed for side erasure control.
Solution Approach 2:
Variable throat height configuration is applied locally to side shields where it provides maximum benefit for side erasure reduction, while top shields maintain uniform simplicity. This localized complexity optimization balances performance improvement with overall device simplicity.
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
This approach improves magnetic performance by allowing independent configuration of shield gaps and throat heights, reducing side erasure and enabling reduced track pitch for ultrahigh density recording while maintaining compatibility with existing fabrication methods.
Implementation Method 1
depositing a side gap over the PMR pole and providing a side shield on the side gap
Implementation Method 2
performing a planarization step that removes a portion of the side shield on the PMR pole
Implementation Method 3
providing a top gap on the PMR pole. The top gap covers substantially only the PMR pole. The method and system also include providing a top shield
Data Source
AI summary
A perpendicular magnetic recording (PMR) head is disclosed. The PMR head includes a perpendicular magnetic recording pole having at least one side, a bottom and a top wider than the bottom. The PMR head also includes at least one side gap, at least one side shield, a to gap on the PMR pole and a top shield. The side gap(s) encapsulate the side(s) of the PMR pole, has at least one width and is between the PMR pole and the side shield(s). The to gap has a thickness such that the ratio of the width(s) to the thickness is greater than one. A portion of the top gap is between at least part of the top shield and the side shield(s).