Magnetic Medium Orientation Control Layer

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current magnetic recording media face challenges in achieving high recording densification while maintaining satisfactory recording and reproducing characteristics, as well as heat fluctuation resistance, due to the trade-off between signal-to-noise ratio and heat fluctuation resistance.

Innovation Solution

A magnetic recording medium is developed with a configuration of a soft magnetic underlying layer, a seed layer comprising a metal oxide or nitride, and an orientation control layer, where the seed layer is formed with a first layer having low surface energy and a second layer with a relatively high surface energy, allowing for the growth of columnar crystals with uniform grain size, enhancing vertical orientation and recording density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a backing layer is simply provided between the vertical magnetic layer and non-magnetic substrate, then magnetic flux entry and exit efficiency is improved, but recording and reproducing characteristics and heat fluctuation resistance are not satisfactory

Engineering Contradiction:

Improvemagnetic flux entry and exit efficiencyVSAvoidrecording and reproducing characteristics and heat fluctuation resistance

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The backing layer is segmented into multiple sub-layers (first backing layer, second backing layer, third backing layer) with different material compositions and thicknesses. Each sub-layer serves specific functions: the first backing layer provides magnetic flux path, the second backing layer controls crystal orientation, and the third backing layer enhances adhesion and protects against corrosion. This segmentation allows optimization of multiple characteristics simultaneously.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The backing layer uses composite material structure combining soft magnetic materials (CoFe, CoFeB), hard magnetic materials (CoPt, CoPd), and non-magnetic materials (Ru, Ir). This composite structure enables simultaneous achievement of magnetic flux efficiency, crystal orientation control, and heat fluctuation resistance that cannot be obtained with a single material.

Inventive Principle:

Principle #40Composite materials

2Productivity

If recording density is increased, then storage capacity is improved, but signal-to-noise ratio and heat fluctuation resistance deteriorate

Engineering Contradiction:

Improverecording densityVSAvoidsignal-to-noise ratio and heat fluctuation resistance

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

Different regions of the magnetic recording medium are given different local qualities through the multi-layered backing structure. The first backing layer provides magnetic flux path with specific magnetic properties, the second backing layer provides crystal orientation control with specific anisotropy, and the third backing layer provides mechanical support and corrosion resistance. This local differentiation enables high recording density while maintaining signal-to-noise ratio and heat fluctuation resistance.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention changes multiple parameters simultaneously: magnetic layer thickness, backing layer composition ratios, crystal grain size distribution, and heating temperature during manufacturing. By optimizing these parameters together rather than individually, the system achieves high recording density while maintaining reliability characteristics.

Inventive Principle:

Principle #35Parameter changes

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 results in a magnetic recording medium with improved vertical orientation, increased recording density, and enhanced electromagnetic conversion characteristics, including a higher signal-to-noise ratio and better heat fluctuation resistance.

Implementation Method 1

a seed layer which is formed with a first layer having low surface energy and a second layer having a relatively high surface energy, so that columnar crystals with uniform grain size can be grown

Methodology Applied

Scientific EffectCrystallization: Crystallisation

Implementation Method 2

an orientation control layer which controls orientations of crystal grains of the magnetic layer

Methodology Applied

Scientific EffectMagnetic anisotropy: Anisotropy

Data Source

PatentUS9245563B2Magnetic medium with an orientation control layer

Publication Date: 2016.01.26 RESONAC HARD DISK CORP

AI summary

Provided is a magnetic recording medium which maintains high vertical orientation of a vertical magnetic layer, and which is capable of realizing high recording densification. In the magnetic recording medium, at least a soft magnetic underlying layer (30), seed layers (31, 32), an orientation control layer (33), and a vertical magnetic layer are laminated in this order on the non-magnetic substrate. The soft magnetic underlying layer (30) has an amorphous or microcrystalline structure. The seed layers (31, 32) include a first seed layer (31) formed from a metal oxide or a metal nitride, and a second seed layer (32) which is formed on the first seed layer and is formed from a metal formed with an island-shape or a net shape. In the orientation control layer (33) and the vertical magnetic layer, respective crystal grains constitute columnar crystals that are continuous in a thickness direction based on the second seed layer (32).