TAMR Head Protrusion for Plasmon Generator Agglomeration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The reliability of thermal assisted magnetic recording heads is compromised due to agglomeration of the plasmon generator's front end surface, which occurs due to heat and stress, leading to deterioration of recording characteristics such as the S/N ratio, as the plasmon generator's metal atoms diffuse and gather, reducing its ability to heat the magnetic recording medium effectively.
Innovation Solution
A thermal assisted magnetic recording head design featuring a protrusion on the air bearing surface that reduces the height of the convex part, allowing it to approach the plasmon generator's front end surface and absorb impact, thereby minimizing heat generation and deformation, thus preventing agglomeration and enhancing the plasmon generator's thermal reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the plasmon generator is directly irradiated with laser light for heating the magnetic recording medium, then the heating efficiency is improved, but the temperature of the plasmon generator drastically rises causing thermal reliability to decrease
Solution Approach 1:
A buffer layer is introduced between the core and the plasmon generator to mediate the light transmission. The buffer layer allows evanescent light to penetrate to the plasmon generator while preventing direct irradiation of the plasmon generator by the propagating light in the core, thus reducing excessive temperature increase while maintaining heating capability
2Ease of manufacture
If the plasmon generator is formed by sputtering or plating to reduce metal density, then the manufacturing ease is improved, but the metal atoms easily diffuse and aggregate under heat and stress causing agglomeration
Solution Approach 1:
A protrusion is formed on the air bearing surface before the plasmon generator to preemptively absorb impact from asperities. This preliminary protective structure prevents direct contact between asperities and the plasmon generator, reducing heat and stress that would cause metal atom diffusion and agglomeration
3Reliability
If the plasmon generator contacts the magnetic recording medium due to asperities, then the impact causes heat generation and stress leading to agglomeration, but preventing contact requires increasing the distance which reduces heating capability
Solution Approach 1:
The protrusion acts as an intermediary protective element between the asperities and the plasmon generator. It absorbs the impact from asperities through controlled contact, protecting the plasmon generator from excessive heat and stress while allowing the plasmon generator to maintain its optimal distance for effective heating of the magnetic recording medium
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 protrusion effectively reduces the occurrence of agglomeration on the plasmon generator's front end surface, maintaining the thermal assisted magnetic recording head's reliability and improving recording characteristics by minimizing contact-induced stress and heat, thereby maintaining the S/N ratio and the capability to heat the magnetic recording medium.
Implementation Method 1
coupled with a portion of the propagating light that propagates through the core in the surface plasmon mode to generate a surface plasmon, propagates the surface plasmon to the generator front end surface and generates near-field light (NF light) at the generator front end surface
Implementation Method 2
a method to convert the laser light into near-field light (NF light) to heat a magnetic recording medium (NF light heating)
Implementation Method 3
The ABS has a protrusion that is closer to the leading side than the generator front end surface in the down track direction, and that protrudes more toward the magnetic recording medium than the generator front end surface upon operation of the thermal assisted magnetic recording head
Data Source
AI summary
A thermal assisted magnetic recording head of the present invention has an air bearing surface (ABS) opposite to a magnetic recording medium, a core that can propagate laser light as propagating light, a plasmon generator that includes a generator front end surface facing the ABS, and a main pole that faces the ABS and emits magnetic flux to the magnetic recording medium. The plasmon generator is opposite to a part of the core and extends to the generator front surface, is coupled with a portion of the propagating light that propagates through the core in the surface plasmon mode to generate a surface plasmon, propagates the surface plasmon to the generator front end surface, and generates near-field light (NF light) at the generator front end surface to irradiate the NF light to the magnetic recording medium. The ABS has a protrusion that is closer to the leading side than the generator front end surface in the down track direction, and that protrudes more toward the magnetic recording medium than the generator front end surface upon operation of the thermal assisted magnetic recording head.