Half Side Shields for Magnetic Writer Fabrication

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Solution Overview

Problem

Conventional magnetic recording heads face performance limitations at higher recording densities, particularly in shingle recording schemes, where they fail to meet design requirements for track edge curvature and areal density due to narrow side gaps and inadequate main pole size.

Innovation Solution

A method for fabricating magnetic recording transducers with half side shields, involving an intermediate layer with sublayers and an etch stop layer, where the side shields terminate short of the main pole's bottom, allowing for tailored geometry and improved performance in shingle recording.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional magnetic recording heads are used, then basic recording functions are maintained, but performance is insufficient at higher recording densities and shingle recording schemes

Engineering Contradiction:

Improveperformance at higher recording densitiesVSAvoidcompatibility with shingle recording schemes

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The side shields are segmented into two distinct portions: a first portion extending from the top of the main pole to a first location, and a second portion extending from the top of the main pole to a second location deeper in the medium. This segmentation allows each portion to serve different functions - the first portion provides standard shielding while the second portion enables shingle recording compatibility by extending further into the medium without requiring a narrow side gap.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the side shields are given different properties and extensions. The first portion has standard shielding characteristics, while the second portion extends deeper into the medium with tailored geometry. This local differentiation allows the transducer to simultaneously maintain conventional recording performance and enable shingle recording schemes with larger main pole sizes.

Inventive Principle:

Principle #3Local quality

2Area of moving object

If the main pole size is increased for shingle recording, then track edge curvature issues are mitigated, but the side gap must be narrowed which creates fabrication and performance issues

Engineering Contradiction:

Improvemain pole sizeVSAvoidside gap width

Core Design Contradiction:

Area of moving objectVSLength of moving object

Solution Approach 1:

The side shields are divided into two portions with different extensions into the medium. This segmentation allows the first portion to provide adequate shielding for a larger main pole configuration, while the second portion extends further to maintain proper magnetic field control without requiring an excessively narrow side gap. The segmented structure decouples the relationship between main pole size and side gap width.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of solving the side gap width problem in the lateral dimension, the invention extends the side shields into the depth dimension (into the medium) with a second portion. This dimensional transition allows the side shields to perform their shielding function more effectively for larger main poles without constraining the side gap width, thereby facilitating shingle recording with larger critical dimensions.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If full side shields extending to the bottom of the main pole are used, then complete shielding is achieved, but fabrication complexity increases and processing consistency is compromised

Engineering Contradiction:

Improveshielding effectivenessVSAvoidfabrication simplicity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The side shields are fabricated as two separate portions rather than a single continuous structure. The first portion extends to a first location while the second portion extends to a second location deeper in the medium. This segmentation simplifies fabrication by allowing each portion to be formed with optimized geometry independently, improving processing consistency while maintaining effective shielding through the coordinated arrangement of both portions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of forming side shields that extend all the way to the bottom of the main pole (excessive action), the invention uses two portions that extend to intermediate locations. The second portion extends deeper than the first to provide adequate shielding for shingle recording, but neither portion needs to reach the full bottom of the main pole. This partial extension approach simplifies fabrication while achieving the necessary shielding effectiveness.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS9343087B1Method for fabricating a magnetic writer having half shields

Publication Date: 2016.05.17 WESTERN DIGITAL TECHNOLOGIES INC

AI summary

A method manufacturing a magnetic writer provides an intermediate layer including multiple sublayers is provided. The sublayers include first and second nonmagnetic layers and an etch stop layer being between the first and second nonmagnetic layers. A trench is formed in the intermediate layer using at least one etch, such as a reactive ion etch. The trench has a location and profile corresponding to the main pole. A main pole having a bottom and a top is provided in the trench. At least a portion of the second nonmagnetic layer is removed using at least a second etch, such as a wet etch process. The etch stop layer is resistant to the at least the second etch. A half side shield is provided on at least part of the first nonmagnetic layer. The half side shield bottom is between the top and the bottom of the main pole.