Thermally-Assisted Magnetic Recording Head Plasmon Generator Reliability
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Solution Overview
Problem
Thermally-assisted magnetic recording heads using plasmon generators made of Au or Ag face reliability issues due to thermal expansion, damage from protective film contact, and degradation in heating performance, leading to reduced reliability and effectiveness.
Innovation Solution
A thermally-assisted magnetic recording head design featuring a plasmon generator with a first inclined surface and an intermediate layer of higher Vickers hardness, positioned between metal layers, and an insulating film to manage temperature and prevent damage, enhancing the plasmon generator's volume and surface area for improved heat dissipation and mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a plasmon generator is formed of Au or Ag to generate near-field light, then heating performance is improved, but reliability deteriorates due to thermal expansion and damage from protective film contact
Solution Approach 1:
The invention uses a composite structure consisting of a soft metal layer (Au or Ag) for plasmon generation and a hard metal layer (Pt, Pd, or Rh) for mechanical protection. This composite material approach allows the soft metal to maintain high heating performance while the hard metal layer prevents thermal expansion damage and protective film contact, thereby resolving the contradiction between heating performance and reliability
Solution Approach 2:
The invention applies different material properties to different parts of the plasmon generator: the soft metal layer (Au or Ag) is used specifically for near-field light generation where high heating performance is needed, while the hard metal layer (Pt, Pd, or Rh) is applied on the front end face and rear end face where mechanical strength and thermal expansion resistance are required. This local differentiation of material quality resolves the contradiction by assigning appropriate material properties to specific functional regions
2Manufacturing precision
If the front end face of the plasmon generator is polished to improve surface quality, then near-field light generation is improved, but the front end face becomes significantly recessed, degrading heating performance
Solution Approach 1:
The hard metal layer (Pt, Pd, or Rh) is deposited on the front end face and rear end face of the plasmon generator before final polishing. This hard layer acts as a protective cushion that prevents excessive material removal during polishing and etching processes, thereby preventing significant recession of the front end face while still allowing surface quality improvement, thus resolving the contradiction between manufacturing precision and heating performance
3Manufacturing precision
If ion beam etching is used to remove smears from the polished surface, then surface quality is improved, but the front end face becomes significantly recessed, degrading heating performance
Solution Approach 1:
The hard metal layer (Pt, Pd, or Rh) is deposited on the front end face before ion beam etching. This hard layer serves as a protective cushion that resists the erosive effect of ion beam etching, preventing significant recession of the front end face while still allowing the underlying soft metal layer to be properly cleaned of smears, thus resolving the contradiction between surface quality improvement and heating performance maintenance
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
The design increases the reliability of the plasmon generator by suppressing temperature rise, preventing damage, and maintaining heating performance, thus enhancing the overall reliability and effectiveness of the thermally-assisted magnetic recording head.
Implementation Method 1
The plasmon generator is configured to excite a surface plasmon based on the light propagating through the core
Implementation Method 2
the surface plasmons concentrate at the front end face, and near-field light is generated from the front end face based on the surface plasmons
Implementation Method 3
The insulating film is disposed between the main pole and the plasmon generator
Data Source
AI summary
A thermally-assisted magnetic recording head includes a main pole, a waveguide, and a plasmon generator. The waveguide includes a core and a cladding. The plasmon generator is configured to excite a surface plasmon based on light propagating through the core. The plasmon generator has a front end face located in a medium facing surface, and a first inclined surface connected to the front end face and facing toward the medium facing surface. The main pole includes an interposition part interposed between the first inclined surface and the medium facing surface. The interposition part has a second inclined surface that is opposed to the first inclined surface with an insulating film interposed therebetween.