JPH0119278Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for monitoring the contact status of a disk head of a magnetic disk device.

When using an acoustic sensor to monitor the state of contact between the disk and the head in a magnetic disk device, AE sensors of various shapes are attached to the head slider or head arm, but the AE sensor is attached to the head slider or head arm. As a result, it is susceptible to vibrations caused by wind pressure, and the results are affected by how the sensor is installed. FIG. 1 shows a conventional sensor mounting method. This structure is easily affected by wind, and since there are two adhesive layers, even the same sensor may have S/S/S depending on how it is attached.
There were drawbacks such as different N values. Therefore, it has been difficult to quantitatively and comparatively evaluate the contact status of several disk heads.

The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to provide a sensor portion of an apparatus for comparatively evaluating the floating stability of a head in a disk device with good reproducibility.

In order to selectively detect only the sound (shock wave) generated when the disk and head of the disk device come into contact with a good S/N ratio, a sensor is installed in the head slider part, which is the direct sound source, in a structure that is not easily affected by wind pressure. It is characterized by Specifically, by using a head slider and a structure in which the acoustic sensor is closely attached to the head slider via a conductive layer, the mounting is stabilized, and variations in S/N due to the mounting method are reduced, and reproducibility is improved. It is something that we try to do.

Figure 2 shows a piezo element 2 with a thickness of 500 ^μm and an area equivalent to that of the head slider 1, with a 1 mm through hole 6 in the center, and a conductive adhesive silver paste 7 attached to the back of the slider. An embodiment of the present invention is shown in which the adhesive is attached in close contact with the adhesive. When the head slider 1 and the disk 3 come into contact, a voltage is induced in the piezo element 2 by the sound waves generated at that time. The voltage is taken out to the outside through lead wires 4a-4b and subjected to signal processing.

FIG. 3 shows an embodiment in which the piezo element is smaller than the back surface of the slider. Conductive adhesive is applied over a wider area than the piezo element, and lead terminals are bonded to the excess adhesive layer.

When the acoustic sensor according to the present invention is used, it has better balance than the conventional structure, is not affected by wind, and can obtain AE output with a good S/N ratio. Furthermore, since the entire surface is bonded, variations between sensors are only caused by variations in the elements themselves, and differences due to mounting methods can be suppressed to a small extent.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram of the conventional sensor in operation, Figure 2 is a conceptual diagram of the sensor of the present invention in operation, and Figure 3 is a conceptual diagram of the sensor of the present invention in operation when the sensor is smaller in area than the slider. FIG. 1... Head slider, 2... Piezo element, 4
...Lead wire, 5...Bonding terminal, 7...
Conductive adhesive layer.

Claims (1)

[Scope of utility model registration request] 1. A sensor-equipped slider comprising a head slider and an acoustic sensor closely attached to the head slider via a conductive layer.