Thin-Film Magnetic Recording Head Light-Absorbing Layer

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Solution Overview

Problem

The existing manufacturing methods for thin-film magnetic recording heads face challenges in achieving accurate shape and size of the main magnetic pole due to interference from HDI sensors or heaters positioned beneath, leading to variations in write width and decreased yield.

Innovation Solution

A thin-film magnetic recording head with a multilayer structure that includes a light-absorbing portion between the main magnetic pole and the sensor or heater, comprising a first and second light-absorbing layer with a transparent layer in between, which reduces reflection light intensity and enhances exposure accuracy by multiplex reflection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If HDI sensor or heater is positioned beneath the main magnetic pole, then the flying height detection and adjustment functions are achieved, but the reflection light from these components interferes with the photoresist exposure, causing variation in trench width and main magnetic pole dimensions

Engineering Contradiction:

Improveflying height detection and adjustmentVSAvoidmain magnetic pole dimension accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

A light-absorbing portion is introduced as an intermediary component between the photoresist and the HDI sensor/heater. This light-absorbing portion absorbs the reflection light from the HDI sensor or heater before it can reach and interfere with the photoresist, thereby eliminating the interference while preserving the functional components beneath the main magnetic pole.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The reflection light from the HDI sensor or heater, which was originally a harmful interference, is converted into a beneficial effect by using it to illuminate the light-absorbing portion. The light-absorbing portion absorbs this light and prevents it from reaching the photoresist, thereby converting the harmful reflection into a useful light-absorption mechanism.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Productivity

If the distance between slider and magnetic recording medium is reduced to a few nanometers, then high density recording is enabled, but the risk of contact and damage between slider and medium increases

Engineering Contradiction:

Improverecording densityVSAvoidslider and medium damage risk

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The HDI sensor provides real-time feedback on the flying height of the slider relative to the magnetic recording medium. This feedback information is used to adjust the slider position dynamically, ensuring that the slider maintains the optimal distance for high-density recording while preventing contact with the medium that would cause damage.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The heater component performs preliminary heating of the magnetic recording medium before the slider contacts it. This preliminary action creates a thermal boundary layer that prevents direct contact between the slider and the medium, thereby preventing damage while enabling the slider to operate at extremely close distances for high-density recording.

Inventive Principle:

Principle #10Preliminary action

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 allows for highly accurate formation of the main magnetic pole with precise size and shape, enabling high-density and accurate perpendicular recording while minimizing the risk of electrical discharge to the magnetic disk.

Implementation Method 1

a light-absorbing portion positioned between the main magnetic pole and the thin film

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

comprising a first and second light-absorbing layer with a transparent layer in between, which reduces reflection light intensity and enhances exposure accuracy by multiplex reflection

Methodology Applied

Scientific EffectMultiplex reflection: Reflection

Data Source

PatentUS8654479B2Thin-film magnetic recording head with thin film which constructs sensor or heater beneath main magnetic pole

Publication Date: 2014.02.18 TDK CORP

AI summary

A thin film magnetic recording head having a multilayer structure in which plural thin films are laminated and being a perpendicular recording type that applies a magnetic field perpendicularly to a magnetic recording medium and performs recording, includes a main magnetic pole exposed on an air bearing surface facing the magnetic recording medium and guiding a magnetic flux toward the magnetic recording medium, a thin film positioned beneath the main magnetic pole from a perspective of a lamination direction and configuring a sensor or a heater configured to determine a distance from the magnetic recording medium of the thin film magnetic recording head, and a light-absorbing portion positioned between the main magnetic pole and the thin film.