Ryosuke Koishi

MEMS-based integrated head/actuator/slider for hard disk drives

We propose a new integrated head/actuator/slider concept for hard disk drives. This slider is batch fabricated on the sacrificial layer of a wafer together with an electrostatic microactuator via micromachining technology. We present the basic integrated head/actuator/slider design, the fabrication and flying-height tests of a micromachined slider body, and the design, fabrication, and testing of a prototype electrostatic microactuator. Slider warpage was analyzed and successfully suppressed to within 0.1 /spl mu/m. The slider was flown over a glass disk at heights of 26-81 nm and at linear velocities of 5-13 m/s. The test results of the electrostatic microactuator showed a stroke of 0.55 /spl mu/m, a very high mechanical resonant frequency of 34 kHz due to its low moving mass of 0.85 /spl mu/g, and a large force, estimated to be 21.3 /spl mu/N, generated by the actuator.

Chemical structure and durability of a plasma-polymerized protective layer for thin-film magnetic disks

Plasma-polymerized films deposited using methane, ethane, acetylene, and benzene as a source material, are generally too thick for practical use (1), (2). Using a diphenylethane monomer, a plasma-polymerized film, less than 10 nm thick, and durable enough for commercial applications, was produced. In this paper, the relationship between the chemical structure and the durability of a plasma-polymerized film is discussed. Films were analyzed using Raman, infrared, and Rutherford backscattering spectroscopies. By increasing the sp2 bonding and decreasing the hydrogen concentration in the films, their durability could be increased. Films of less than 10 nm in thickness film were more durable than sputtered carbon films of a comparable thickness. The new film also showed promising tribological characteristics for high-performance magnetic disk-drive applications. Presented as a Society of Tribologists and Lubrication Engineers paper at the STLE/ASME Trlbology Conference In St. Louis, Missouri, October 14–16, 1991

The trinity slider for ultra low flying heights

To increase the recording density of magnetic disk drives, the flying height of the heads needs to be reduced. To achieve this. we have to design a slider that maintains reliability, flying stability. and wide manufacturing tolerance at ultra low flying heights. In this paper, we report a new bmity slider with improvements for ultra low flying height. It has high sbffness because of the high negative pressure, such that flying height fluctuation is reduced Moreover, by balancing the positive and negative form ratios, a fairly constant flying height is achieved for different radii.

Super Proximity Trapezoid Shaped Slider

To achieve an ultralow flying height for magnetic heads, we developed a super proximity trapezoid shaped slider having leading edge width narrower than the trailing edge width. Compared to a conventional slider, it has lower inertia and mass and can maintain a higher roll stiffness. Therefore, it can reduce the impact force resulting from scattered projections on disk surfaces. In addition, it can reduce the flying height fluctuations due to slider rail irregularities, because it is supported at three points by air pressure. As a result, its flying stability is highly reliable.