Protruding Member Shields Write Head in Thermal Recording
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Solution Overview
Problem
Thermally-assisted magnetic recording heads face challenges in protecting the write head section, particularly the plasmon generator and magnetic pole, due to temperature-induced protrusion of the medium facing surface, which can lead to damage from contact with the magnetic recording medium or dust particles, despite existing solutions like heat radiating films and projected portions that fail to prevent damage effectively.
Innovation Solution
Incorporating a protruding member made of a different metal than the plasmon generator and magnetic pole, with a higher melting point and hardness, positioned between the waveguide core and the medium facing surface, which is heated and expanded to protrude towards the magnetic recording medium, thereby protecting the main write head section from direct contact and damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a plasmon generator and magnetic pole are used in close proximity to generate near-field light and write magnetic field, then thermally-assisted magnetic recording can be achieved, but the medium facing surface protrudes toward the magnetic recording medium due to temperature-induced expansion, causing damage from contact with the magnetic recording medium or dust particles
Solution Approach 1:
A protruding member made of a different metal than the plasmon generator and magnetic pole is positioned between the waveguide core and the medium facing surface. This intermediary component protrudes toward the magnetic recording medium to shield the main write head section (plasmon generator and magnetic pole) from direct contact with the magnetic recording medium or dust particles, thereby preventing damage while maintaining the close-proximity configuration needed for thermally-assisted magnetic recording
Solution Approach 2:
The protruding member is made of a metal with different properties (higher melting point and hardness) than the plasmon generator and magnetic pole materials. This parameter change in material properties allows the protruding member to withstand the thermal and mechanical conditions better, providing protection to the write head section while maintaining operational temperature and structural integrity
2Reliability
If the medium facing surface is covered with a protective film, then damage from contact with magnetic recording medium or dust particles can be prevented, but the protective film itself protrudes and becomes susceptible to damage when brought into contact with the magnetic recording medium or dust particles
Solution Approach 1:
The protruding member serves as a protective intermediary that prevents the protective film from direct contact with the magnetic recording medium or dust particles. By positioning the protruding member between the protective film and the magnetic recording medium, the system protects the protective film from damage while maintaining the shielding function
Solution Approach 2:
The protruding member is positioned in advance to create a protective barrier before contact with the magnetic recording medium or dust particles occurs. This beforehand cushioning prevents the protective film from being damaged by direct contact, extending the life of the protective film and the write head section
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 protruding member effectively shields the write head section from mechanical and thermal damage during operation, maintaining the recording density while preventing exposure of the plasmon generator and magnetic pole to the magnetic recording medium or dust particles.
Implementation Method 1
The protruding member is formed of a metal that is different from both a material that forms the magnetic pole and a material that forms the plasmon generator... the light received at the second end face causes the protruding member to be heated
Implementation Method 2
the light received at the second end face causes the protruding member to be heated and expanded to cause the first end face to get protruded toward the magnetic recording medium
Implementation Method 3
a known method for generating near-field light is to use a plasmon generator, which is a piece of metal that generates near-field light from plasmons excited by irradiation with light
Implementation Method 4
the plasmon generator has a near-field light generating part located in the medium facing surface, and is configured so that a surface plasmon is excited on the plasmon generator
Implementation Method 5
The light for use in generating near-field light is typically guided through a waveguide, which is provided in the slider, to the plasmon generator disposed near a medium facing surface of the slider
Implementation Method 6
a write head section including an induction-type electromagnetic transducer for writing... the magnetic pole has an end face located in the medium facing surface, and produces a write magnetic field for writing data on the magnetic recording medium
Implementation Method 7
When writing data, a write magnetic field and heat are applied almost simultaneously to the area of the magnetic recording medium where to write data, so that the area rises in temperature and drops in coercivity
Data Source
AI summary
A thermally-assisted magnetic recording head includes: a medium facing surface; a magnetic pole; a waveguide including a core and a cladding; a plasmon generator; and a protruding member. The protruding member is disposed between the medium facing surface and a front end face of the core facing toward the medium facing surface. The protruding member has a first end face located in the medium facing surface, and a second end face facing toward the front end face of the core and receiving light having propagated through the core and passed through the front end face. The protruding member is formed of a metal different from both a material forming the magnetic pole and a material forming the plasmon generator. The protruding member is heated and expanded by the light received at the second end face, so that the first end face gets protruded toward a magnetic recording medium.