JPH0644717A - Magnetic head - Google Patents

Abstract

PURPOSE:To provide the magnetic head which can prevent the attraction of the magnetic head to a magnetic recording medium by the adequate surface roughness of an ABS surface and can increase the number of durable times of CSS operations. CONSTITUTION:A head core 7 consisting of a magnetic material is joined via a gap 8 to one end face of a slider 2 and ruggedness having <=5mum pitch size and <=50 angstrom height size is formed on the surface of the ABS surface 4 of the slider 2 facing the magnetic recording medium 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head, and more particularly, to magnetic information processing such as predetermined magnetic recording or reproduction by contacting a magnetic recording medium in a stationary state and levitating from the magnetic recording medium in an operating state. Regarding a magnetic head to perform.

[0002]

2. Description of the Related Art Generally, in a magnetic head for recording and reproducing information on a hard disk, which is a magnetic recording medium of a magnetic recording device such as a computer, the magnetic recording medium is rotated by rotating the magnetic recording medium. 2. Description of the Related Art Floating magnetic heads are often used for recording or reproducing on a magnetic recording medium by floating only a minute gap from the medium.

FIG. 7 and FIG. 8 show such a conventional magnetic head. The magnetic head 1 has a slider 2 made of ferrite or the like, and the slider 2 faces the magnetic recording medium 3. ABS (Air Bearing)
The surface 4 is composed of two rails 5 and 5 parallel to the relative movement direction of the magnetic recording medium 3. Between the rails 5 of the slider 2, there are formed negative pressure grooves 6 for floating the slider 2 above the magnetic recording medium 3, and one end of the slider 2 on the side of the rail 5 has a negative pressure groove 6. A substantially U-shaped head core 7 made of a magnetic material is joined with glass or the like via a gap 8. As shown in FIG. 8, the magnetic head 1 having the above-described structure is attached to the tip end portion of a gimbal 10 mounted on the driving device 9, and by driving the driving device 9, the magnetic head 1 is magnetized through the gimbal 10. The head 1 is driven to approach and separate from the magnetic recording medium 3, and the magnetic recording medium 3 is scanned.

In the conventional magnetic head 1, when the magnetic recording medium 3 is stopped, the magnetic head 1 is in contact with the magnetic recording medium 3 at the retracted position, and the negative pressure groove 6 is generated by the rotation of the magnetic recording medium 3. The surface of the magnetic recording medium 3 is floated low by the flow of air passing therethrough, and predetermined magnetic recording or reproduction is performed. When the magnetic recording medium 3 is stopped, the magnetic head 1 is moved to the magnetic recording medium 3 again.
Is stopped by touching.

Conventionally, the ABS surface 4 of the slider 2 of the magnetic head 1 is formed to be extremely smooth in order to improve the CSS (contact start stop) characteristic.

[0006]

However, in the conventional magnetic head 1, since the ABS surface 4 of the slider 2 is formed to be smooth, it is used for a relatively short time while the CSS operation is repeated. The ABS surface 4 of the slider 2 is abraded over time, so that when the magnetic head 1 contacts the magnetic recording medium 3, the magnetic head 1 is attracted to the magnetic recording medium 3 and the durability of CSS operation is improved. It has a problem that the number of times is extremely short.

The present invention has been made in view of the above-mentioned points, and it is possible to prevent the magnetic head from being attracted to the magnetic recording medium by the appropriate surface roughness of the ABS surface, and to remarkably increase the number of times of CSS operation durability. It is an object of the present invention to provide a magnetic head that can be manufactured.

[0008]

In order to achieve the above object, a magnetic head according to the present invention comprises a head core made of a magnetic material bonded to one end surface of a slider via a gap, and the slider is mounted on the magnetic recording medium. In a magnetic head which floats from above to perform magnetic information processing of the magnetic recording medium, irregularities having a pitch dimension of 5 μm or less and a height dimension of 50 Å or less are formed on the surface of the ABS surface of the slider facing the magnetic recording medium. It is characterized by that.

[0009]

According to the magnetic head of the present invention, the slider AB
Since the unevenness is formed on the S surface and the pitch dimension of the unevenness is 5 μm or less and the number of projections of the unevenness is large, the pitch dimension of the unevenness is large and the number of projections is small. As a result, it is possible to prevent a sudden increase in the true contact area, and reduce the amount of wear of the protrusions. As a result, even if the height of the unevenness is 50 angstroms or less, the CSS operation is suppressed. The durability of the magnetic head can be remarkably improved, and the attraction of the magnetic head can be appropriately prevented.

[0010]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 shows an embodiment of the magnetic head according to the present invention. The lower surface of the slider 2 of the magnetic head 1 is
The ABS surface 4 faces the magnetic recording medium 3. In this embodiment, the slider 2 is made of fine crystal grain ferrite. This fine crystal grain ferrite has a crystal grain size of about 2 to 3 μm, and as shown in FIG.
The surface 4 is provided with fine irregularities 11 by a predetermined processing means such as a physical etching method such as reverse sputtering or ion milling, a submerged lapping method or a chemical etching method.

In this embodiment, the irregularities 11 on the ABS surface 4 have a fine crystal grain size of about 2 to 3 μm as described above. Therefore, by processing the irregularities 11, the pitch size of the irregularities 11 is 5 μm or less. Then, the height dimension of the unevenness 11 is formed to be 50 angstroms or less.

Next, the irregular dimension of the ABS surface 4 will be considered.

Normally, the ABS surface 4 of the slider 2 and the surface of the magnetic recording medium 3 are not in surface contact with each other, and minute protrusions 12 formed on the tips of the irregularities 11 on the ABS surface 4 of the slider 2 are formed. It contacts the magnetic recording medium 3, and the contact area between the protrusion 12 and the surface of the magnetic recording medium 3 is the true contact area. By repeating the CSS operation of the magnetic head 1, the minute projections 12 on the ABS surface 4 are worn and the true contact area is increased, which causes friction between the ABS surface 4 of the slider 2 and the magnetic recording medium 3. The coefficient increases, and eventually the magnetic head 1 is attracted to the magnetic recording medium 3 and the CSS operation becomes impossible. Therefore, the durability of the CSS operation is due to an increase in the true contact area between the protrusion 12 on the ABS surface 4 of the slider 2 and the magnetic recording medium 3. If the initial friction coefficient is the same, the true contact area due to wear is increased. Differences occur depending on the degree of increase. That is, when the true contact area is rapidly increased, the durability of the CSS operation is small, and conversely, when the true contact area is gradually increased, the durability of the CSS operation is improved.

Now, considering the pitch dimension P of the unevenness 11 on the ABS surface 4, for example, as shown in FIGS. 2 and 3, due to the difference in the pitch dimension P of the unevenness 11, the magnetic recording medium 3 has a different pitch. The total number of the projections 12 contacting the surface changes, and the pitch dimension P of the unevenness 11 is 1/2.
4 times the average, the projections 12 are 4 times larger in average,
Assuming that the total area of the ABS surface 4 of the slider 2 is Sa, the total number N of the protrusions 12 in contact is N.
Will be proportional to Sa / P ² .

[0016] When the magnetic head 1 is pressed against the magnetic recording medium 3 by the load W of the gimbal spring, the dispersed load Wd received by one protrusion 12 is divided by more protrusions 12 when the pitch dimension P of the unevenness 11 is small. Therefore, for example, if the pitch dimension P is ½, the projections 12 of a quadruple
Therefore, the dispersed load Wd of each protrusion 12 becomes ¼, and the dispersed load Wd may be proportional to the square of the pitch dimension P of the unevenness 11, as shown in the following equation. Recognize.

[0017] Furthermore, since the true contact area Sr that influences the friction coefficient with respect to the magnetic recording medium 3 is due to the elastic-plastic deformation of the protrusions 12, it is proportional to the distributed load Wd and the total number of protrusions 12 in contact within the ABS surface 4. It becomes proportional to N, and the true contact area Sr becomes a constant value determined by the load W regardless of the difference in the pitch dimension P of the unevenness 11.

[0018] However, when the pitch dimension P of the unevenness 11 is formed small, the protrusion 1 formed on the ABS surface 4 of the slider 2
Since the number of two projections and the height distribution of the projections 12 are large, the projections 12 that are initially in contact with the magnetic recording medium 3 are smaller than those when the pitch dimension P of the unevenness 11 is large and the number of the projections 12 is small. Even when worn, new projections 12 come into contact with each other one after another, and it is possible to prevent a sudden increase in the true contact area Sr. Further, since the dispersed load Wd of each projection 12 becomes small, The wear amount of 12 can be reduced.

Therefore, when the pitch dimension of the concavities and convexities 11 is made small, if the height dimension of the concavities and convexities 11 is the same, the number of times of endurance of CSS operation can be improved.

On the other hand, the unevenness 11 on the ABS surface 4 of the slider 2
Considering the height dimension δ of the
When the pitch dimensions are the same, as shown in FIG. 4, if the height dimension of the concavities and convexities 11 is large, the increase in the contact area due to the CSS operation is small, so the number of cycles of CSS operation is extended.

However, when the height dimension δ of the concavities and convexities 11 is processed to be large, a gap formed by compounding a gap member other than ferrite, a metal film in a MIG head (metal-in-gap head), and the like. In the part, since the processing rate is different from the ABS surface 4,
It is difficult to form the ABS surface 4 and the gap portion in a uniform shape, and depending on the crystal orientation of the ferrite crystal grains forming the gap portion, the ferrite grains of the ABS surface 4 and the ferrite grain of the gap portion may be different from each other. There is a difference in the processing amount of the above, and it is extremely difficult to uniformly process the entire ABS surface 4.

Further, if a step is formed in the gap portion, there arises a problem that abrasion powder is accumulated in the gap portion. Further, in the case of the MIG head, the boundary surface between the metal film and the ferrite is generated. There is a problem that the so-called pseudo gap noise becomes large due to the step difference. For example, as shown in FIG. 5, the magnetic head 1 in which the height dimension δ of the unevenness 11 is 100 angstroms and the magnetic head 1 in which the height dimension δ is 40 angstroms are formed.
Comparing with, the height dimension δ of 100 angstrom
It can be seen that the magnetic head 1 having a value of 1 has a higher value of pseudo gap noise.

Therefore, when the processing for forming the height dimension δ of the unevenness 11 to be large is performed, it is necessary to manufacture so that the gap portion is not processed, which is extremely difficult in reality. Therefore, as in this embodiment, the unevenness 1
Even if the height dimension δ of 1 is relatively small, by forming the pitch dimension of the concavities and convexities 11 small, it is possible to reduce a sudden increase in the true contact area due to wear, and therefore, it is possible to realize a substantial CSS operation. It is possible to increase the durability.

FIG. 6 shows a magnetic head 1 and a magnetic head 1 according to this embodiment in which fine crystal grain ferrite having a crystal grain size of about 1 to 4 μm is processed to form irregularities 11 having a pitch size of about 1 to 4 μm on the ABS surface 4. With respect to the magnetic head 1 on which the unevenness 11 having a pitch dimension of about 5 to 15 μm is formed, the experimental results of measuring the number of times of CSS operation durability according to the height dimension δ of each unevenness 11 are shown.

According to the results of this experiment, in the case of the magnetic head 1 in which the pitch dimension of the irregularities 11 is small, even if the height dimension δ of the irregularities 11 is 20 to 40 angstroms, the C of about 90,000 times is obtained.
It can be seen that the SS operation durability count can be obtained, and this durability count is compared with the magnetic head 1 in which the pitch dimension of the unevenness 11 is large, the CSS operation durability count of the height dimension δ of the unevenness 11 being 60 angstroms or more. It can be seen that the durability is equivalent to.

Therefore, in this embodiment, the above A
By forming the concavities and convexities 11 on the BS surface 4 so that the pitch dimension is 5 μm or less, even when the height dimension is 50 angstroms or less, it is possible to remarkably improve the durability of the CSS operation, and It is possible to properly prevent the occurrence of suction of the head 1. Moreover, since the height of the unevenness 11 is small, it is possible to extremely easily process the unevenness 11, and it is possible to prevent the deterioration of the magnetic characteristics due to the occurrence of a step or the like in the gap portion.

The present invention is not limited to the above-mentioned embodiments, but various modifications can be made as necessary.

[0028]

As described above, in the magnetic head according to the present invention, the unevenness of the ABS surface is formed to have a pitch dimension of 5 μm or less, so that even if the height dimension thereof is 50 angstroms or less, the CSS is reduced. The durability of the operation can be remarkably improved, and the magnetic head can be properly prevented from being attracted. Moreover, since the height of the irregularities is small, the irregularities can be processed very easily, and it is possible to prevent the deterioration of the magnetic characteristics due to the occurrence of a step or the like in the gap portion.

[Brief description of drawings]

FIG. 1 is a partially enlarged explanatory view showing a magnetic head of the present invention.

FIG. 2 is an explanatory view showing a concavo-convex shape with a small pitch dimension in FIG.

FIG. 3 is an explanatory view showing a concavo-convex shape having a larger pitch dimension than that of FIG.

FIG. 4 is a diagram showing the number of times of endurance of a CSS operation due to a difference in height of unevenness.

FIG. 5 is a diagram showing pseudo gap noise due to difference in height of unevenness.

FIG. 6 is a diagram showing an experimental result of measuring the number of times of endurance of CSS operation due to a difference in height of the unevenness between the magnetic head according to the present invention and a conventional magnetic head having a large uneven pitch size.

FIG. 7 is a perspective view of a slider portion showing a conventional magnetic head.

FIG. 8 is a side view showing a conventional magnetic head.

[Explanation of symbols]

 1 magnetic head 2 slider 3 magnetic recording medium 4 ABS surface 11 unevenness 12 protrusion

Claims (1)

[Claims] 1. A magnetic head, comprising a head core made of a magnetic material bonded to one end surface of a slider via a gap, and flying the slider from the magnetic recording medium to perform magnetic information processing of the magnetic recording medium. A magnetic head characterized in that irregularities having a pitch dimension of 5 μm or less and a height dimension of 50 Å or less are formed on the surface of the ABS surface of the slider facing the magnetic recording medium.