JPH05258266A - Floating magnetic head - Google Patents

Abstract

PURPOSE:To prevent the attraction between the head and a recording medium at contact.start.stop and to stabilize the head by decreasing a contact area between the head floating surface and the recording medium without changing the floating surface width of the floating magnetic head. CONSTITUTION:A slit groove which is about 0.2mm width and about 0.1mm depth from the floating surface, is worked at a constant pitch on the floating surfaces 12, 13 opposing to the recording medium except the vicinity of a gap. Soft glass is interposed in the slit groove and stepped difference between a magnetic block body which forms the magnetic head and the soft glass interposed in the slit groove part is made at the time of working the floating surfaces 12, 13 or by a washing method, thus the contact area with the recording medium is decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating magnetic head used in a fixed magnetic disk device.

[0002]

2. Description of the Related Art With the downsizing and high density recording of fixed magnetic disk devices, there has been an increasing demand for downsizing of magnetic heads, high accuracy, and stable low flying height. .. Conventionally, in a fixed magnetic head device, a floating magnetic head has been used, which utilizes dynamic pressure generated by a fluid layer of air generated by running of a recording medium to float with a minute gap between the recording medium and the recording medium. .. By the way, in order to float this floating magnetic head on a magnetic recording medium with a minute gap, it is necessary to finish the surface of the magnetic recording medium into a mirror surface state.
With the increasing demand for high-density recording, magnetic disk media such as 3.5-inch and 2.5-inch have become highly mirror-finished as the magnetic film is thinned by a sputtered film, a plated film, or the like. However, when the floating magnetic head is used in a contact start / stop (hereinafter referred to as CSS) method, the recording medium surface of the floating magnetic head has good flatness as compared with the conventional magnetic recording medium surface. In addition, when the mirror-finished surface is left in a close contact state for a long time, the floating magnetic head is attracted to the surface of the magnetic recording medium. When the magnetic recording medium is run in such an adsorbed state, the surface of the magnetic recording medium is scratched, the information recorded on the surface of the magnetic recording medium is destroyed, and a floating magnetic head is attached. There was a problem of damaging the spring. FIG. 11 is a perspective view of a conventional floating magnetic head, and FIGS. 12 and 13 show a state of an air bearing surface shape for improving CSS characteristics of the conventional floating magnetic head. In FIG. 11, 1 is a C-shaped core for winding, 2 is an I-shaped core having an air bearing surface for flying over a magnetic medium, and 15 is a data track gap vicinity. There is a track portion 18 that is long and has a predetermined track width. Also,
The air bearing surface 17 has a leading taper portion 16 on the air inflow end side with respect to the rotation of the magnetic medium. Reference numeral 22 is a beveled surface for determining the width of the air bearing surface, that is, the air bearing surface area for determining the flying height when the magnetic medium reaches a predetermined number of revolutions, and for regulating the air bearing surface height. Conventionally, as a measure against CSS, for example, as disclosed in Japanese Patent Publication No. 58-21329, the air bearing surface of a floating magnetic head as shown in FIG.
As shown in FIG. 12, a cylindrical slider 23 having a small contact area is desirable in order to place it apart from the (disk) or to significantly reduce the suction force. Leading part
A tapered portion 16 is provided. Further, in Japanese Patent Laid-Open No. 1-251308, a magnetic recording medium of a floating magnetic head using polycrystalline ferrite, that is, peaks and valleys as shown in FIG. 13 which is an enlarged view of a portion B of the air bearing surface 17 in FIG. The depth difference is 50 Å ~ 200 Å, and the repeating pitch of peaks and valleys is 5 μm to 20 μm on average. This is to prevent adsorption by reducing the contact area with the magnetic recording medium due to the difference in the depth of the ridges and valleys, thereby reducing the contact resistance.

[0003]

However, in the former case, the magnetic recording medium has a line contact in the case of an arc surface, and a point contact in the case of a spherical surface, and an arc surface having a radius of 10 m or more, Alternatively, there is a problem that it is difficult to obtain a stable and uniform surface because it is necessary to process the spherical surface.
In the latter case, the concave and convex are formed by utilizing the physical and mechanical properties of polycrystalline ferrite.
As one example of the manufacturing method, it is described that minute removal processing is performed by the reverse sputtering method, but there is a problem that it takes man-hours, and in any of the above cases, there was a problem in mass production. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems, and to provide a floating magnetic head that does not affect the flying height, has a small contact area with a magnetic recording medium, and is suitable for mass production. ..

[0004]

In order to achieve the above object, the floating magnetic head of the present invention has a soft glass interposed at a constant pitch on the surface other than the vicinity of the gap facing the magnetic recording medium, and that portion is the magnetic head. It has a depth that does not affect the levitation characteristics (mechanically minute steps are provided at equal intervals), and the contact area between the air bearing surface of the magnetic head and the magnetic recording medium is reduced to attract them. This is to prevent it and to obtain stable CSS characteristics.

[0005]

Therefore, according to the present invention, the attraction between the floating magnetic head and the recording medium can be prevented, and the processing can be performed without using any special device, equipment and technique.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a step in a position that does not change the flying height of the air bearing surface and excludes the magnetic gap position and that is substantially perpendicular to the running direction of the medium. The step portion is formed of bonding glass. That is, the bonding glass is filled between the ferrite portions of the air bearing surface to be alternately configured, and the bonding glass portion forms a recess with respect to the plane of the ferrite portion. An embodiment of a floating magnetic head of the present invention will be described below with reference to the drawings. 1 is an external perspective view of a floating magnetic head of the present invention, and FIG. 2 is a partially enlarged view (enlarged view of A portion) of FIG. 3 to 8 are perspective views and side views based on the manufacturing process for explaining the floating magnetic head of the present invention. In FIG. 1, 1 is C for winding
C-shaped core of mold shape, 2 is an I-shaped core having an air bearing surface,
Reference numeral 12 is a ferrite material air bearing surface corresponding to the air bearing surface 17 in FIG. 11, and the air bearing surface 12 is provided with a plurality of slit grooves. Reference numeral 13 is a soft glass air bearing surface in which slit glass is filled with bonding glass, and 14 is a leading taper portion, which corresponds to the leading taper portion 16 in FIG. Figure 2
In FIG. 2, 9 is a slit groove tip, which shows the shape of the tip of the slit groove having the slit width 10 on the air bearing surface 12 of the ferrite material, which is R-shaped in FIG.
This shows a situation where a diamond wheel in the R state in which a slit groove is inserted is processed, and a U-shaped slit groove may be used. 13 is a soft glass air bearing surface filled with bonding glass, 21 is a ferrite I-shaped core 2 which is a hard and brittle material when the ferrite material air bearing surface 12 is mirror-finished, and a step is formed on the bonding glass surface having low hardness. It is the amount of step difference between the ferrite and the soft glass that occurs, and the amount of step difference is at most 500Å (the reason for the step difference will be described later). Reference numeral 25 shows a slight R-shape at the edge portion of the step generated when the bonding glass is welded to the ferrite slit groove portion and then the mirror surface processing of the ferrite material air bearing surface 12, that is, the boundary portion between the ferrite and the soft glass.

In the manufacturing process of the present invention, as shown in FIG. 3, the C-shaped core 1 and the I-shaped core 2 are bonded together by fused glass so that the required gap length is obtained. In FIG. 4, the slit groove 3 is formed and ground by the cutting wheel 26 on the air bearing surface 8 excluding the C-shaped core 1 and the gap vicinity 15, and the slit groove may be processed by a single blade wheel. Simultaneous forming and grinding with a multi-layer cutting wheel may be used. The tip of the slit groove tip 9 may be rounded or U-shaped. In addition, the depth of the slit groove
19 needs to be deeper than the apex part of the magnetic gap. Moreover, the total height value from the air bearing surface 8 to the bottom surface indicates the total height value 20 of the floating magnetic head in the final state.
It is in a state where m to 0.5 mm is added. Next, in FIG. 5, the glass for binding the slit portion, that is, the soft glass 11 is placed on the slit-processed magnetic substance block 24 made in FIG. 6, the air bearing surface 8 side is ground so that the air bearing surface 8 has a shape in which a plurality of slits are filled with glass from the vicinity of the gap 15 except the C-shaped core 1. A plurality of magnetic head cores can be obtained. The magnetic head core block having the width in the completed state of the magnetic head is obtained by grinding and cutting this at the cutting position 4 of the slider width regulation so as to have the required magnetic head width. Next, as shown in FIG. 7, the coil winding portion 5 is obtained by grinding the core block grinding surfaces 6 on both side surfaces of the C-shaped core 1. Then, as shown in FIG. 8, the track surface 7 and the air bearing surface 8 are ground to a predetermined size, and the air bearing surface 8 is polished to obtain the magnetic head having the shape shown in FIG. In addition,
In polishing the air bearing surface 8, a tin plate is generally used as a polisher and diamond abrasive grains are used as an abrasive. The air bearing surface is formed by a C-shaped core 1 and an I-shaped core 2. Ferrite is used for these, and soft glass is used for the slit portion. Ferrite is a hard and brittle material, and soft glass is lower in hardness than ferrite, but it is not a brittle material.Therefore, when a tin plate is used as a polisher, the soft glass part has a recessed portion with respect to the ferrite part. Occurs.
Further, by using various polisher materials other than the tin plate as the polisher, for example, a lens polishing cloth or a pitch, the concave step of the soft glass portion with respect to the ferrite surface can be further increased. This is determined by the hardness of the polisher material, the load on the workpiece, and the like. Further, in the case of polycrystalline ferrite, a step occurs along the grain boundary region, but this step can be controlled by polishing conditions, and the maximum step is 50Å or less. Further, in the boundary region between the ferrite and the soft glass, a minute R is generated although it varies depending on the height of the step difference of the concave portion of the soft glass. That is, it is generally confirmed that the larger the step height of the recess is, the larger the R becomes, and the surface of the ferrite causes surface sag in the boundary region. It has a concave part, and the ferrite part becomes a curve with a radius of 10 m or more,
Since the air bearing surface is composed of a plurality of slits, it has a plurality of wavy shapes. At this time, the step difference between the maximum value of the ferrite part and the minimum value of the soft glass part recess is 500
It has been confirmed that reaching the Å position does not affect the flying height of the magnetic head. In this method, the slit groove 3 was filled with the soft glass 11, but the purpose was to remove the ferrite chipping in the slit groove portion, the falling of crystals, and the effects of dust, etc. It is not always necessary to fill the soft glass 11 as long as the above can be achieved completely. FIG. 9 is a side view of a floating magnetic head according to one embodiment of the present invention, and FIG. 10 is an enlarged view of a boundary portion between ferrite and soft glass on the floating surface of the floating magnetic head.

[0008]

As is apparent from the above embodiments, according to the present invention, it is possible to easily reduce the contact between the floating magnetic head and the recording medium, prevent the adsorption of both, and stabilize the C content.
It is possible to obtain SS characteristics. Further, even if compared with other means for improving CSS characteristics, it is possible to perform processing without using a special device, equipment and technique, and therefore, the productivity is excellent.

[Brief description of drawings]

FIG. 1 is a perspective view of a floating magnetic head according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of an air bearing surface A portion of FIG.

FIG. 3 is a schematic diagram of a manufacturing process of a floating magnetic head according to an embodiment of the present invention.

FIG. 4 is a schematic diagram of a manufacturing process of a floating magnetic head according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of a manufacturing process of a floating magnetic head according to an embodiment of the present invention.

FIG. 6 is a schematic diagram of a manufacturing process of a floating magnetic head according to an embodiment of the present invention.

FIG. 7 is a schematic diagram of a manufacturing process of a floating magnetic head according to an embodiment of the present invention.

FIG. 8 is a schematic diagram of a manufacturing process of a floating magnetic head according to an embodiment of the present invention.

FIG. 9 is a side view of a floating magnetic head according to an embodiment of the present invention.

FIG. 10 is an enlarged view of a ferrite / soft glass boundary portion of a floating magnetic head according to an embodiment of the present invention.

FIG. 11 is a perspective view of a conventional floating magnetic head.

FIG. 12 is a state diagram of an air bearing surface shape for improving conventional contact start / stop characteristics.

FIG. 13 is an enlarged view of part B in FIG.

FIG. 14 is a diagram showing the relationship between a conventional floating magnetic head and the surface of a magnetic recording medium.

[Explanation of symbols]

1 ... C-type core, 2 ... I-type core, 3 ... Slit groove, 4 ... Cutting position of slider width regulation, 5 ... Coil winding part, 6 ... Core block grinding surface, 7 ... Track surface, 8, 17 ... Levitation Surface, 9 ... Slit groove tip,
10 ... slit width, 11 ... soft glass, 12 ... ferrite material air bearing surface, 13 ... soft glass air bearing surface, 14,16 ... leading taper portion, 15 ... near gap portion, 18 ... track portion, 19 ... slit groove depth 20 ... Overall height of floating magnetic head, 21 ... Step difference between ferrite and soft glass,
22… Slope grinding surface, 23… Cylinder surface slider, 24… Slit grooved magnetic block, 25… Ferrite and soft glass interface, 26… Cutting wheel.

Claims (1)

[Claims] 1. In a magnetic head, a soft glass is interposed at a constant pitch on a surface other than the vicinity of a gap facing a magnetic recording medium, and the portion has a depth that does not affect the flying characteristics of the magnetic head, By reducing the contact area between the air bearing surface of the magnetic head and the magnetic recording medium, it is possible to prevent adsorption between the magnetic head and the magnetic recording medium and to obtain stable contact start / stop (CSS) characteristics. And a floating magnetic head.