Thermally-Assisted Magnetic Head Expanded Heat Radiating Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional thermally assisted magnetic heads face issues with melting, deformation, and chipping of the plasmon antenna and main magnetic pole layer due to self-heating, which affects the precision and stability of near-field light generation for high-density magnetic recording.
Innovation Solution
A thermally assisted magnetic head design featuring a near-field light generating layer with an expanded part that acts as a heat radiating layer, connected to the near-field light generating part but positioned further from the medium-opposing surface, to dissipate heat generated during near-field light production, thereby preventing melting and deformation, and reducing heat transfer to the main magnetic pole layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a plasmon antenna is used to generate near-field light for heating the magnetic recording medium, then the recording precision is improved, but the plasmon antenna and main magnetic pole layer are subject to melting, deformation, and chipping due to self-heating
Solution Approach 1:
The near-field light generating layer is divided into two functional parts: a light-receiving portion that receives laser light and generates near-field light, and a heat-radiating portion that radiates heat away from the generating layer. This segmentation allows the light-receiving portion to maintain its precise shape for near-field light generation while the heat-radiating portion handles thermal dissipation, preventing melting and deformation of the plasmon antenna and main magnetic pole layer
Solution Approach 2:
The heat-radiating portion acts as an intermediary between the light-receiving portion and the main magnetic pole layer. It receives heat from the light-receiving portion through thermal conduction and radiates it away, serving as a thermal buffer that protects the main magnetic pole layer from direct heat exposure and prevents chipping and deformation
2Quantity of substance
If the magnetic fine particles are made smaller to increase recording density, then the recording density is improved, but the magnetization stability decreases due to reduced volume
Solution Approach 1:
The invention changes the temperature parameter of the magnetic recording medium dynamically. By using near-field light to locally heat the recording region, the coercive force of the magnetic fine particles is temporarily reduced, enabling magnetization reversal even for very small particles with low thermal stability. After recording, the region cools down and the magnetization becomes stable again
3Stability of the object's composition
If the magnetic energy of the magnetic fine particles is increased to improve magnetization stability, then the magnetization stability is improved, but the coercive force increases making data recording more difficult
Solution Approach 1:
The invention uses periodic thermal action to temporarily reduce the coercive force during the recording process. Laser light is applied periodically to heat the recording region, reducing the coercive force of the magnetic fine particles at the moment of magnetization reversal. This allows recording in media with high magnetic energy products that would otherwise be too difficult to write
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 design enhances the efficiency of near-field light generation while preventing melting and deformation of the near-field light generating layer and chipping of the main magnetic pole layer, ensuring stable and precise heating of the magnetic recording medium.
Implementation Method 1
When light enters an opening smaller than the wavelength of light, the light slightly seeps from the opening and locally exists near the opening. The light locally existing near the opening is called near-field light.
Implementation Method 2
an optical waveguide which guides light to the near-field light generating layer
Implementation Method 3
an expanded part connected with the near-field light generating part at a position more distant from the medium-opposing surface than is the near-field light generating part, to radiate heat generated when the near-field light is generated
Implementation Method 4
the thin-film magnetic head employing the thermally assisted magnetic recording records data while instantaneously heating and thereby increasing the temperature of a portion of the magnetic recording medium where data will be recorded
Data Source
AI summary
A thermally assisted magnetic head includes a main magnetic pole layer, a near-field light generating layer having a generating end part generating near-field light arranged within a medium-opposing surface, and an optical waveguide guiding light to the near-field light generating layer. The optical waveguide has a waveguide end face arranged within the medium-opposing surface and an upper end face on a side closer to the main magnetic pole layer. The thermally assisted magnetic head has an interposed layer which is in direct contact with an outer surface of the optical waveguide. The near-field light generating layer has a near-field light generating part having the generating end part and an expanded part connected with the near-field light generating part. The expanded part has a base part arranged above the upper end face of the optical waveguide and extended base part connected with the base part.