Wire Lead Designs for Magnetic Write Devices

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Solution Overview

Problem

Magnetic recording storage devices face challenges in confining magnetic fields effectively at high areal densities, leading to off-track effects and requiring stronger write fields, which can be achieved by incorporating a conductor to generate an assistive magnetic field, but this introduces issues with field gradient and lead reliability due to corrosion and suboptimal electrical and thermal properties.

Innovation Solution

A magnetic writer design featuring a write element with a conductor proximate to the tip, connected by conductive leads and heat sinks that deliver current to generate an augmenting magnetic field, with side shields and recessed leads to minimize corrosion and maintain performance, optimizing the conductor's dimensions for maximum field strength and gradient.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a conductor is incorporated adjacent to the write pole tip to generate a stronger write field, then the magnetic field strength at the medium is improved, but the field gradient deteriorates due to the finite thickness of the conductor in the down track direction

Engineering Contradiction:

Improvemagnetic field strengthVSAvoidfield gradient

Core Design Contradiction:

ForceVSManufacturing precision

Solution Approach 1:

The patent applies local quality by making the conductor thickness non-uniform in the down-track direction, with the thickness varying along the conductor length. This creates locally optimized field generation: thicker regions provide stronger field while thinner regions maintain better field gradient, resolving the contradiction between overall field strength and localized field gradient requirements.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If leads are exposed to deliver current to the conductor, then electrical connectivity is achieved, but reliability deteriorates due to corrosion from exposure to corrosion inducing agents

Engineering Contradiction:

Improveelectrical connectivityVSAvoidlead reliability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent extracts the leads from the corrosive environment by recessing them into the body of the write pole, removing them from exposure to corrosion inducing agents at the medium confronting surface. This maintains electrical connectivity while protecting the leads from corrosion, thereby improving reliability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a non-magnetic material as an intermediary between the recessed leads and the corrosive environment. This intermediary material fills the recess and protects the leads from direct contact with corrosion inducing agents, allowing electrical connectivity to be maintained while preventing corrosion.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If side shields are incorporated in the writer, then field confinement is improved, but electrical and thermal properties deteriorate when leads are replaced with magnetic materials

Engineering Contradiction:

Improvefield confinementVSAvoidelectrical and thermal properties

Core Design Contradiction:

Object-generated harmful factorsVSEase of operation

Solution Approach 1:

The patent uses a non-magnetic material as an intermediary to replace magnetic materials in the lead regions. This non-magnetic material maintains good electrical and thermal properties while allowing the side shields to provide field confinement, resolving the contradiction between field confinement and electrical/thermal performance.

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

The solution effectively confines and strengthens the magnetic field, improving writing capabilities at high coercivity media while reducing corrosion risks and maintaining electrical and thermal performance, thus addressing the challenges of field confinement and reliability.

Implementation Method 1

A conductor is proximate the write element tip and first and second conductive leads are connected to the conductor and configured to deliver a current to the conductor to generate a second field that augments the first field

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The write element is operable to generate a first field at the medium confronting surface

Methodology Applied

Scientific EffectElectromagnetic field generation: Magnetic Field

Data Source

PatentUS9159339B2Wire and wire lead designs for a wire-assisted magnetic write device

Publication Date: 2015.10.13 SEAGATE TECH LLC

AI summary

A magnetic device includes a write element having a write element tip that defines a medium confronting surface. The write element is operable to generate a first field at the medium confronting surface. A conductor is proximate the write element tip and first and second conductive leads are connected to the conductor and configured to deliver a current to the conductor to generate a second field that augments the first field. First and second side elements are disposed on opposite sides of the write element tip in a cross-track direction at the medium confronting surface. At least a portion of the first conductive lead is disposed adjacent the first side element on a side opposite the medium confronting surface, and at least a portion of the second conductive lead is disposed adjacent the second side element on a side opposite the medium confronting surface.