Thermally-Assisted Magnetic Recording Head Plasmon Generator Heat Dissipation
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Solution Overview
Problem
Thermally-assisted magnetic recording heads face challenges with inefficient heat dissipation and overheating in plasmon generators, leading to reduced performance and reliability due to the conversion of light energy into heat, which affects the generation of near-field light and application of writing magnetic fields.
Innovation Solution
A thermally-assisted magnetic recording head design that includes a waveguide, a plasmon generator with a first configuration member for near-field light generation and a second configuration member acting as a heat sink, and a separator layer between the plasmon generator and the main magnetic pole, allowing for efficient heat dissipation and maintaining a small distance between the near-field light generation end surface and the main magnetic pole for effective heating and writing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the plasmon antenna is directly irradiated with light to generate near-field light, then near-field light generation is achieved, but the conversion efficiency is low and excessive heat is generated causing volume expansion and protrusion from the ABS
Solution Approach 1:
A waveguide is introduced as an intermediary component between the light source and the plasmon antenna. The waveguide transmits light to the plasmon antenna, enabling efficient energy transfer while allowing thermal management. This mediator structure separates the light input function from the heat generation location, improving overall system efficiency and thermal control.
Solution Approach 2:
The heat dissipation function is extracted and separated from the plasmon antenna structure. By positioning the plasmon antenna away from the ABS surface and providing dedicated heat dissipation paths through the substrate, the harmful thermal effects are removed from the critical recording interface, preventing protrusion and maintaining recording reliability.
2Power
If the plasmon antenna volume is kept small for efficient near-field light generation, then near-field light generation capability is improved, but heat dissipation becomes insufficient leading to overheating and material degradation
Solution Approach 1:
The plasmon antenna system is segmented into distinct functional zones: a compact plasmon antenna region for efficient near-field light generation, and a separate heat dissipation region extending into the substrate. This segmentation allows the antenna to maintain small volume for high power operation while the extended structure provides sufficient thermal management capacity.
Solution Approach 2:
Heat dissipation is addressed by transitioning from two-dimensional surface-level heat management to three-dimensional subsurface heat pathways. The plasmon antenna structure extends vertically into the substrate, creating additional thermal conduction paths in the depth dimension, thereby improving heat dissipation without increasing the lateral footprint at the ABS surface.
3Reliability
If the MR element is positioned far from the magnetic recording medium to prevent contact during expansion, then contact prevention is achieved, but reading capability is lost
Solution Approach 1:
The heat expansion problem is extracted and isolated from the MR element positioning. By providing dedicated heat dissipation structures and thermal management pathways separate from the MR element, the system prevents thermal expansion-induced contact issues without requiring the MR element to be positioned far from the recording medium, thereby preserving reading capability.
4Power
If excessive heat is generated in the plasmon antenna, then near-field light generation is affected, but additional problems occur such as breakage, material migration, and damage to the magnetic recording medium
Solution Approach 1:
Heat dissipation structures and thermal management pathways are built into the system design before operation begins. The substrate and supporting structures are configured with adequate thermal conductivity and heat sinking capacity to prevent temperature rise before it reaches damaging levels, cushioning against thermal damage proactively rather than reactively.
Solution Approach 2:
The substrate and heat dissipation structures serve as intermediary thermal management components between the plasmon antenna and the magnetic recording medium. These intermediaries conduct heat away from the antenna while isolating the recording medium from direct thermal exposure, preventing material migration, breakage, and other thermal damage.
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 heat dissipation, prevents overheating, and maintains the efficiency of near-field light generation and writing magnetic field application, enabling high-density thermally-assisted magnetic recording with improved reliability and performance.
Implementation Method 1
The waveguide transmits light incident from the light source toward the air bearing surface
Implementation Method 2
a plasmon generator that couples in a surface plasmon mode with light propagating through the waveguide to generate surface plasmons, allows the surface plasmons to propagate toward the air bearing surface, and generates near-field light at the near-field light generation end surface
Implementation Method 3
Most of the energy of the light radiated onto the plasmon antenna is reflected at the surface of the plasmon antenna or converted into heat
Implementation Method 4
a second configuration member that is provided to be in contact with the first configuration member or is integrally provided with the first configuration member, and that is in contact with main magnetic pole, the second configuration member terminating at a position recessed from the air bearing surface
Data Source
AI summary
A plasmon generator of a thermally-assisted magnetic recording head has a first configuration member having a near-field light generation end surface at an ABS, and a second configuration member being in contact with main magnetic pole, and terminating at a front end portion of a slope positioned at the position recessed from the ABS. An end part of a separator layer, which is interposed between the main magnetic pole and the first configuration member, on a side opposite to the ABS is at a position more recessed from the air bearing surface than the front end portion of the slope of the second configuration member.