Heat-Assisted Recording Head Surface-Plasmonic Plate
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Solution Overview
Problem
Current heat-assisted magnetic recording (HAMR) near-field transducers face challenges in efficiently coupling surface plasmon polaritons to high plasmonic loss materials, leading to inadequate heat transfer and potential reliability issues due to the recessed configuration of the Au resonator and Rh peg, which affects thermal gradient and heat removal.
Innovation Solution
A configuration where a mechanically robust but high-loss plasmonic material is used as a second surface-plasmonic plate with a peg extending closer to the media-facing surface, attached to a low-loss plasmonic plate, and a heat-spreading plate is employed to enhance heat transfer and thermal gradient, with the second surface-plasmonic plate being thinner and directly attached to the heat-spreading plate for improved heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a low-loss plasmonic material (e.g., Au) is used as the surface-plasmonic plate, then plasmonic coupling efficiency is improved, but mechanical robustness and heat dissipation capability deteriorate
Solution Approach 1:
The patent employs a composite structure consisting of a first surface-plasmonic plate made of low-loss plasmonic material (e.g., Au) and a second surface-plasmonic plate made of mechanically robust material (e.g., Rh). This composite configuration allows the first plate to provide efficient plasmonic coupling while the second plate provides mechanical support and enhanced heat dissipation capability, thereby resolving the contradiction between coupling efficiency and mechanical robustness.
2Reliability
If the surface-plasmonic plate is recessed from the media-facing surface, then reliability is improved by reducing exposure to wear, but heat transfer efficiency and thermal gradient deteriorate
Solution Approach 1:
The patent introduces a dimensional solution by extending the second surface-plasmonic plate closer to the media-facing surface than the first plate. This creates a multi-level recessed structure where the first plate remains recessed for reliability while the second plate extends closer to maintain efficient heat transfer and thermal gradient. The peg structure on the second plate further optimizes this by positioning the heat-generating region closer to the media.
3Strength
If a thick surface-plasmonic plate is used, then mechanical robustness is improved, but heat dissipation efficiency and thermal gradient deteriorate
Solution Approach 1:
The patent segments the surface-plasmonic plate into two distinct layers: a first plate made of low-loss plasmonic material and a second plate made of mechanically robust material. The second plate is specifically designed to be thinner than a conventional single plate, optimizing the balance between mechanical robustness and heat dissipation efficiency. This segmentation allows each layer to perform its specialized function without compromising the other.
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 reduces temperature rise at the peg, enhances thermal gradient, and improves reliability by maximizing heat transfer from the second surface plasmonic plate to the heat-spreading layer and magnetic pole, thereby supporting high-density recording.
Implementation Method 1
combine a total internal reflection of the dielectric waveguide with a surface plasmon confinement of the heat spreading plate to excite TM-even mode in the hybrid waveguide
Implementation Method 2
combine a total internal reflection of the dielectric waveguide with a surface plasmon confinement of the heat spreading plate
Implementation Method 3
Light energy from the TM-even mode propagating from the hybrid waveguide to the surface-plasmonic plate causes the surface plasmonic plate to focus the light energy to heat a recording medium
Implementation Method 4
focus the light energy to heat a recording medium
Implementation Method 5
enhance heat transfer from the second surface plasmonic plate to the heat-spreading layer and magnetic pole
Data Source
AI summary
A recording head includes a dielectric waveguide that extends towards a media-facing surface of the recording head. A hybrid waveguide is near the media-facing surface and includes the dielectric waveguide and a heat spreader plate having a crosstrack dimension that is at least twice that of a core of the dielectric waveguide. The hybrid waveguide is operable to combine a total internal reflection of the dielectric waveguide with a surface plasmon confinement of the heat spreading plate to excite TM-even mode in the hybrid waveguide. A surface-plasmonic plate is in contact with the heat spreader plate, the second surface-plasmonic plate has a peg extending from an enlarged portion. Light energy from the TM-even mode propagating from the hybrid waveguide to the surface-plasmonic plate causes the surface plasmonic plate to focus the light energy to heat a recording medium.