Near-Field Transducer With Plasmonic Heat Sinks for HAMR Thermal Management
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Solution Overview
Problem
Current heat-assisted magnetic recording (HAMR) technologies face challenges in achieving high data density due to the diffraction limit, which prevents optical components from focusing light to the scale required for tiny hotspots, and struggle with thermal management, leading to unreliable recording head temperatures.
Innovation Solution
The use of a near-field transducer (NFT) with a channel waveguide and multiple heat sinks, where a dielectric layer with a lower refractive index than the waveguide enhances plasmonic excitation, and a second heat sink with a plasmonic material extends across the gap to efficiently conduct heat away from the NFT, improving thermal management and recording performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single heat sink is used in HAMR, then the structure is simple, but thermal management is insufficient leading to unreliable recording head temperatures
Solution Approach 1:
The heat sink is divided into multiple separate heat sinks positioned at different locations around the optical component. Each heat sink independently manages thermal load from different regions, providing comprehensive thermal control while maintaining structural simplicity through modular design
Solution Approach 2:
The multiple heat sinks act as intermediary thermal management components between the optical component and the surrounding environment. They facilitate heat transfer from the optical component to the air or heat dissipation structures without requiring direct complex thermal coupling
2Manufacturing precision
If optical components are used to focus light for high data density, then data density can be increased, but the diffraction limit prevents focusing to the scale required for tiny hotspots
Solution Approach 1:
The patent changes the fundamental parameter of light focusing by transitioning from far-field optical focusing to near-field plasmonic focusing. This enables sub-diffraction-limit hotspot sizes by utilizing surface plasmon resonance and evanescent field coupling, achieving the required precision for high-density recording
Solution Approach 2:
The patent replaces conventional optical focusing mechanisms with near-field plasmonic excitation mechanisms. Instead of using lens-based optical systems limited by diffraction, the invention uses direct near-field coupling between the optical component and the recording medium to achieve sub-diffraction hotspot formation
3Reliability
If the second heat sink contacts the waveguide, then thermal management is improved, but plasmonic material on the heat sink may interfere with optical energy communication
Solution Approach 1:
The plasmonic material is applied selectively to specific regions of the second heat sink where it enhances plasmonic excitation without interfering with optical energy communication. The heat sink structure is designed with differentiated zones: one region contacts the waveguide for thermal management, while another region with plasmonic material provides enhanced optical-field coupling
Solution Approach 2:
The second heat sink is constructed as a composite structure combining thermal conduction materials with plasmonic materials. This allows simultaneous achievement of effective heat dissipation through the thermal conductive portion and enhanced plasmonic excitation through the plasmonic material portion, without mutual interference
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 enables significant temperature reduction of the recording head, enhances plasmonic excitation, and maintains media temperature rise efficiency, thereby improving data density and reliability in HAMR systems.
Implementation Method 1
A dielectric layer with a lower refractive index than the waveguide enhances plasmonic excitation
Implementation Method 2
a second heat sink with a plasmonic material extends across the gap to efficiently conduct heat away from the NFT
Implementation Method 3
causing the energy to propagate to a near-field transducer proximate a write pole and a media-facing surface of the recording head, the energy causing a surface plasmon resonance of the near-field transducer to heat a magnetic recording medium
Data Source
AI summary
An apparatus comprises a writer, a near-field transducer (NFT), a channel waveguide proximate the NFT, a dielectric layer between the NFT and waveguide, and a plurality of heat sinks. A first heat sink comprises a gap and contacts the NFT and the writer. A second heat sink extends across the gap of the first heat sink and between the NFT and a heat reservoir component, such as a return pole of the writer. The channel waveguide may contact the second heat sink, such as by encompassing a peripheral portion of the second heat sink. The second heat sink may have at least an outer surface comprising a plasmonic material, and may be configured to enhance plasmonic excitation of the NFT.