Two-Layer Front Shield With Active Control Device

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Solution Overview

Problem

In magnetic data storage devices, synchronizing the response of the write pole with the front shield to the magnetomotive force (MMF) is challenging, affecting the accuracy and speed of magnetic field transitions between data bits.

Innovation Solution

A two-layer front shield with an active shield control (ASC) device, where a copper wire is embedded and electrically isolated by dielectric materials, is used to synchronize the response of the write pole and the front shield, enhancing the dynamic field gradient during magnetic recording.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a single-layer front shield is used, then the structure is simple and easy to manufacture, but the synchronization response between write pole and front shield is insufficient, affecting write accuracy and speed

Engineering Contradiction:

Improvewrite accuracyVSAvoidfront shield structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The front shield is divided into two separate layers (first front shield layer and second front shield layer) with the ASC device positioned between them. This segmentation allows each layer to contribute differently to the flux circuit closure, improving the synchronization response and write accuracy while maintaining manufacturability through standard layering processes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The ASC (Active Shield Control) device is introduced to dynamically control the magnetization state of the front shield layers. By actively adjusting the magnetic state of the ASC device, the system can optimize the flux circuit closure timing, thereby improving write accuracy and speed without requiring a fundamentally more complex shield structure.

Inventive Principle:

Principle #15Dynamics

2Speed

If ASC device is added to synchronize response, then write speed and field gradient are enhanced, but manufacturing complexity increases

Engineering Contradiction:

Improvewrite speedVSAvoidfabrication process

Core Design Contradiction:

SpeedVSEase of manufacture

Solution Approach 1:

The ASC device is integrated within the existing front shield structure by positioning it between the first and second front shield layers. This merging approach allows the ASC device to be incorporated into the standard head fabrication process without requiring entirely new manufacturing steps, thus enhancing write speed while minimizing the increase in manufacturing complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The ASC device is nested within the front shield assembly, specifically positioned between the two front shield layers. This nesting configuration allows the ASC device to be embedded during the layer deposition process, utilizing existing manufacturing capabilities while achieving enhanced write speed and field gradient control.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Reliability

If copper wire is embedded in front shield, then electrical isolation is achieved, but additional dielectric layers increase structure complexity

Engineering Contradiction:

Improveelectrical isolationVSAvoidlayer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Dielectric layers are introduced as intermediary materials between the copper wire ASC device and the magnetic shield layers. These dielectric layers provide necessary electrical isolation and insulation, ensuring reliable electrical separation while being integrated into the existing layer deposition process, thus minimizing the increase in overall structural complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 configuration improves write accuracy and speed by ensuring a fast and sharp transition between magnetic bits, exceeding the capabilities of current technologies and allowing for efficient fabrication using common materials and processes.

Implementation Method 1

A disc drive is an example of a data storage system that uses magnetic field for writing and reading data. Transducers write information to and read information from data surfaces of the discs.

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

how quickly the trailing or front shield can close the flux circuit, establishing the write field gradient in the process

Methodology Applied

Scientific EffectMagnetic flux: Magnetic Field

Data Source

PatentUS9495979B1Magnetic recording head front shield formation

Publication Date: 2016.11.15 SEAGATE TECH LLC

AI summary

Implementations disclosed herein provide a method of forming a first layer of a front shield in a magnetic recording head, depositing an active shield control (ASC) device on the first layer, and forming a second layer of the front shield on top of the ASC device and the first layer of the front shield. In another implementation, an apparatus includes a write pole, and a two layer front shield formed on the write pole, including an ASC device between the two layers of the front shield.