Magnetic Recording Head Pole Tip Shield Graded Side Shields

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Solution Overview

Problem

Decreases in form factor size and increases in areal density of data storage devices interfere with the ability to generate sufficient write field amplitude or write field gradient, leading to writeability and reliability issues due to adjacent track interference (ATI).

Innovation Solution

The implementation of a pole tip shield with side shield portions, specifically graded magnetic moment materials that decrease in magnetic moment along the down-track direction, and contoured designs to optimize the write contour and reduce magnetic flux leakage, enhancing the writeability and limiting ATI.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the form factor size is decreased and areal density is increased, then the data storage capacity is improved, but the write field amplitude and write field gradient become insufficient due to adjacent track interference

Engineering Contradiction:

Improveareal densityVSAvoidwriteability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The pole tip shield is segmented into multiple functional regions including a leading edge portion, side shield portions, and a trailing edge portion. This segmentation allows each region to perform specific functions: the leading edge portion shapes the write field gradient, the side shield portions limit flux leakage to adjacent tracks, and the trailing edge portion maintains field amplitude, collectively resolving the contradiction between high areal density and sufficient write field characteristics

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the pole tip shield are assigned different magnetic moment properties. The side shield portions use graded magnetic moment materials with decreasing magnetic moment along the down-track direction, while the leading and trailing edge portions have different magnetic moment characteristics. This local differentiation optimizes the write field distribution, enabling sufficient write field amplitude and gradient while limiting adjacent track interference in high areal density configurations

Inventive Principle:

Principle #3Local quality

2Reliability

If a pole tip shield with graded magnetic moment materials is implemented, then adjacent track interference is reduced and writeability is enhanced, but the device complexity increases

Engineering Contradiction:

ImprovewriteabilityVSAvoidpole tip shield structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The pole tip shield is constructed using composite magnetic moment materials, specifically graded magnetic moment materials where the magnetic moment varies spatially. The side shield portions use materials with decreasing magnetic moment along the down-track direction, while the leading and trailing edge portions use materials with different magnetic moment characteristics. This composite approach enables sophisticated field control to enhance writeability and reduce adjacent track interference, though it increases manufacturing complexity

Inventive Principle:

Principle #40Composite materials

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 solution effectively reduces adjacent track interference, enhances writeability, and maintains the reliability of data storage by optimizing the write field and field gradient, improving the performance of data storage devices.

Implementation Method 1

the side shield portions are fabricated of a graded magnetic moment material forming graded side shield portions. The graded side shield portions provide a magnetic moment that decreases in the down-track direction along a length of the side shield portions

Methodology Applied

Scientific EffectMagnetic moment gradient: Magnetic Field

Implementation Method 2

the pole tip shield includes a leading edge portion and side shield portions having a shortened length extending along a partial length of side edges of the pole tip... The shortened length of the side shield portions form a terminal edge surface spaced forward of the trailing edge of the pole tip

Methodology Applied

Scientific EffectMagnetic flux confinement: Magnetic Field

Data Source

PatentUS8810964B2Magnetic recording head having a pole tip shield and a pole-shield gap region

Publication Date: 2014.08.19 SEAGATE TECH LLC

AI summary

A write element including a pole tip shield is disclosed. In embodiments disclosed, for example, the pole tip shield includes side shield portions fabricated of a graded magnetic moment material to form graded side shield portions having a magnetic moment that decreases in the down-track direction along a length of the side shield portions. In another embodiment, the pole tip shield includes side shield portions having a shortened length extending along a partial length of side edges of the pole tip. In illustrated embodiments, the side shield portions are formed of a contoured body having an indented portion forward of the leading edge of the pole tip. The indented portion has a rounded indented surface contour forming a rounded profile for a gap region between a leading edge portion of the pole tip shield forward of the leading edge of the pole tip.