Seiji Yoneoka

Stiction free slider for the smooth surface disk

We describe the superior tribological performance for a slider with three cylindrical pads on the air bearing surfaces on a smooth surface disk. Using photolithography, we can form the cylindrical pads with a controlled surface area and uniform height on the air bearing surfaces of a magnetic head. In addition to the reduction of the apparent contact area of the head/disk interface, by applying an excessive amount of lubricant to the vertical surface of the pads, we can lower the static friction with an ultra smooth surface (Ra=0.3 nm). Moreover, we observed no wearing of the pads after 100,000 CSS cycles.

Development of integrated suspension system for a nanoslider with an MR head transducer

The requirements for a suspension assembly with a 2-mm nanoslider and a magnetoresistive (MR) head transducer to improve the head-disk interface are discussed. An integrated suspension system with a miniature monolithic flexible body with the signal pattern directly on the body is introduced. Experiments showed that the suspension system has good characteristics to carry a nanoslider and an MR head transducer. >

A negative pressure microhead slider for ultralow spacing with uniform flying height

A negative-pressure head slider for ultralow flying has been developed which features a newly shaped air bearing surface that gains sufficient suction force because the distance between the two side rails gradually widens from the leading to the trailing edge of the slider. The slider has a fast takeoff, and the flying height is insensitive to disk velocity. It also avoids the dust accumulation problem seen in the conventional negative-pressure slider. The sliders absence of taper suppresses generation to floating force, resulting in a microslider with relatively wide siderails. The flare angle of the siderails also contributes to making the flying height insensitive to the yaw angle, resulting in a uniform flying height over the entire disk surface. The recess needed to generate suction is a shallow 2 mu m, so the flexible rail shape is easily manufactured using photolithography. >

Dynamics of inline flying-head assemblies

Heads for high-performance disk storage must be able to withstand an acceleration of dozens of G-force and be capable of positioning to submicron precision. A measuring technique that can totally analyze the flight stability and access ability of the slider was developed. It involves three-dimensional modal analysis of the suspension using a laser Doppler anemometer, a laser Doppler vibrometer, and simultaneous measurement of spacing fluctuation. Using this system to examine an inline head, it was found that notable lateral and torsional modes of the suspension vibration were caused by the access acceleration of the rectangular wave, and that there is pronounced spacing fluctuation. In addition, these lateral vibrations cause the pivot to slip, which may cause problems in high-speed head access. >

A design of high performance inline head assembly for high-speed access

A high-performance inline head assembly that stabilizes head sliders during high-speed access has been developed. It features a triangular, truss-bridge-shaped load beam and a flexure supported at both ends by the load beam. These improvements made the resonant frequency in the access direction twice that of the conventional inline head assembly, reducing spacing fluctuation at high frequencies and allowing the actuator to be positioned more precisely. The proturberance was moved to the load beam from the flexure, lowering the moment by decreasing the distance between where the force was applied to the slider and the sliders center of gravity. Experiments showed that the resonant frequency of the inline head assembly is 8 kHz in the access direction, which is about twice that of the conventional inline head assembly. Spacing fluctuation is about 50% that of the conventional inline head assembly. >

Fast take-off negative pressure slider

Using computer simulation, the flying characteristics of a conventional positive pressure head slider and two types of zero-load negative pressure head sliders are compared. One of the negative pressure head sliders is aimed at high stiffness (HS type), and the other is at CSS durability by virtue of its fast taKe-off design (FTO type). The reverse step of the FTO is deeper than that of the HS type. On the FTO type, suction increases gradually as the disk speed increases, and the slider takes off at a lower velocity than the HS type. So the suction of the FTO type is still low when the slider takes off from the disk. By experiment, we confirmed that the FTO prototype head impacts little on the medium during CSS, and also has superb flying stability.

Vibro-loading of magnetic head assemblies for hard disk drives

Experimental results of a new load unload method, called vibro-loading, are reported. This self-loading method uses a negative-pressure slider without any additional mechanisms to carry the slider to the loading point. Vertical natural frequency vibrations of the suspension are excited by a voice coil motor. Experimental results show that low-level seek acceleration enables stable loading with a working distance of 100 mm. >