Using a Novel Floating Grinding Process to Improve the Surface Roughness Parameter of a Magnetic Head

Area of Science:

• Materials Science and Engineering
• Surface Metrology
• Nanotechnology

Background:

• Achieving ultra-smooth surfaces is critical for magnetic head performance.
• Surface defects like blackspots and scratches degrade magnetic head functionality.
• Existing grinding methods struggle to meet stringent surface roughness requirements.

Purpose of the Study:

• To enhance the surface roughness of magnetic heads.
• To investigate the efficacy of ultrafine nanodiamond slurry in fine grinding.
• To develop and validate a novel floating grinding process for magnetic heads.

Main Methods:

• Utilized an ultrafine nanodiamond slurry (100 nm) for magnetic head grinding.
• Developed and implemented a novel floating grinding (lapping) method.
• Optimized experimental parameters including pit ratio, plate flatness, rotation speed, and vibration frequency.
• Characterized grinding plates and analyzed surface morphology, size, and elemental composition of defects using microscopy (SEM, TEM) and spectroscopy (AES, AFM).

Main Results:

• Optimized grinding conditions achieved a plate flatness of 1.8 μm and specific pit ratio.
• Nanodiamond slurry particle size was identified as crucial for surface improvement.
• The novel floating lapping method combined with small-sized diamond slurry significantly reduced surface roughness.
• Achieved a minimum surface roughness of 0.165 nm on the magnetic head slider surface.
• Eliminated blackspots and scratches, leading to a superior surface finish.

Conclusions:

• The novel floating grinding method using ultrafine nanodiamond slurry is highly effective for achieving ultra-smooth magnetic head surfaces.
• Optimized process parameters and slurry characteristics are key to minimizing surface roughness and defects.
• This technique offers a significant advancement in magnetic head manufacturing for improved performance and reliability.