JPH09251744A - Magnetic head and magnetic disk device - Google Patents

Abstract

(57) Abstract: Even in low-flying magnetic recording, when a magnetic head to which a lubricant is transferred is left on a magnetic disk for a long time due to device stop, the lubricant wraps around the ABS surface. Avoids the adsorption of to secure running durability. A magnetic head having an air bearing surface (ABS) separated into a front portion and a rear portion, wherein a rear ABS surface area of the slider is 0.02 (mm ² ) or less. The flying height of the outflow end of the front air bearing surface of the head is 3
A magnetic head having a thickness of 0 (nm) or more and a flying height at the outflow end of the rear air bearing surface of 10 (nm) or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device used for external storage of a computer, and more particularly to a magnetic head.

[0002]

2. Description of the Related Art A magnetic disk medium used in a magnetic disk device has a Co alloy magnetic film formed by a sputtering method or a plating method after forming irregularities on an aluminum substrate which has been subjected to a Ni-P plating treatment. In general, a protective film is further formed thereon for the purpose of improving durability and corrosion resistance, and a lubricating layer is generally provided on the outermost surface by a dip method or spray coating. Recently, a glass substrate is used to form irregularities on a base layer.

Since the surfaces of these magnetic disk media are extremely smooth, in a magnetic disk device that employs a contact start stop (CSS) system in which the device is started and stopped while the magnetic head and the magnetic disk are in contact with each other. However, there are problems such as attraction of the magnetic head and deterioration of running durability. Therefore, various types of magnetic disk media / heads have been studied in order to improve these problems.

For example, the magnetic head slider disclosed in Japanese Unexamined Patent Publication No. 6-52645 has two tapered sections located outside to obtain a desired levitation force in order to be compact and lightweight and to have optimum levitation characteristics. It comprises a pad and a third pad located approximately centrally with respect to the longitudinal axis.

[0005]

With the recent high density recording of magnetic disks, the spacing between the trailing edge of the magnetic head and the magnetic disk has been reduced to about 20 to 50 (nm). Along with this, when the magnetic head floats, the lubricant on the magnetic disk transfers to the magnetic head, and in this state the rotation of the magnetic disk stops and the magnetic head is left on the magnetic disk for a long time. In addition, there is a problem that the lubricant adhering to a portion other than the ABS surface of the magnetic head wraps around the ABS surface and is adsorbed, which makes restart impossible. Conventionally, these problems have been solved by optimizing the surface roughness of the magnetic disk and the thickness / type of the lubricating layer. However, in order to maintain the current flying height of the magnetic head, it is becoming difficult to take measures from the viewpoint of flying characteristics and running durability. Further, the magnetic head slider shown in the above-mentioned known example achieves the flying stability in the low flying height region, but since this point is not taken into consideration, it is described in, for example, the patent example. The third pad area calculated from the numerical value is larger than 0.029 (mm ² ), and the lubricant entwined between the magnetic head slider and the magnetic disk forms a meniscus, which causes adsorption and cannot restart. was there. Further, since the floating amount of the outflow end of the above-mentioned first and second pads is low, the lubricant is accumulated, and after the apparatus is stopped in this state, the lubricant is absorbed by the wraparound of the lubricant by leaving it for a long time. There was a problem that would occur.

Therefore, the present invention has excellent levitation characteristics even in an extremely low levitation of about 10 (nm), and attracts the magnetic head for a long time after the apparatus is stopped by transferring the lubricant to the magnetic head. It is an object of the present invention to provide a magnetic head that can avoid the problem.

[0007]

In order to solve the above problems, in a head divided into a front ABS portion (inflow taper portion) and a rear ABS portion, the rear ABS area is 0.0
It should be 2 (mm ² ) or less.

According to the present invention, even if the floating magnetic head moves in the data area, the transfer of the lubricant is limited to the rear ABS portion, and even if the apparatus is stopped and left in this state, the magnetic head slider / The area of the meniscus formed by the lubricant entwined between the magnetic disks is small, and the attraction force can be suppressed small. Even when the magnetic head continuously slides during CSS in the CSS area, the front ABS portion having a relatively large area also comes into contact with the rear ABS portion, and the contact stress is dispersed. The wear of the magnetic transducer and the magnetoresistive sensor (head element) / disk protective film arranged in the above is suppressed. As a result, an error due to damage to the head element and an error due to damage to the magnetic disk medium do not occur, and good CSS yield strength can be secured.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to Examples. FIG. 1 shows a magnetic head according to the present invention.

As a constitution, it comprises two pads having tapered sliding surfaces and one or a plurality of pads having an input / output function portion. The magnetic head of this structure has a taper 2
Two pad sections float on the air, and writing / reading is performed by the pad section provided at the rear.

In the first embodiment, in the head (size of 2.0 (mm) × 1.6 (mm)) in which the front ABS portion (inflow taper portion) and the rear ABS portion (magnetic head element portion) are separated. , The outflow end flying height of the front ABS portion is 30 (nm), and the outflow end flying height of the rear ABS portion is 10 (nm).
The area of S part is 0.50 (mm ² ) (1 pad width 0.25
(Mm) × length 1.0 (mm) was fixed, and the area of the rear ABS part was changed as shown in Table 1 to prepare. In this case, one without the rear ABS part was also prepared in which the area of the rear ABS part was assumed to be 0 (mm ² ).

[0012]

[Table 1]

In Example 2, the area of the rear ABS is shown in Table 1.
The condition that the front ABS part and the flying height are the same as that of the first embodiment was prepared.

As Comparative Example 1, the outflow end flying height 10 (n
The area of the ABS part of the 2-rail head of m) is 0.54 (m
m ² ) (1 pad width 0.15 (mm) x length 1.8 (m
m)), and as a comparative example 2, the outflow end flying height 10 (n
The area of the ABS part of the two-rail head of m) is 0.90 (m
m ² ) (1 pad width 0.25 (mm) x length 1.8 (m
m)) was created.

As basic data, FIG. 2 shows the results of investigation of changes in the amount of lubricant deposited on the outflow end face while changing the flying height.
Shown in For the test head, the flying height of the slider of Comparative Example 2 was adjusted to 5, 7, 10, 15, 20, 25, 3 by adjusting the load.
Those changed to 0, 40, 50 (nm) were used.
A 3.5 ″ disk was used as a test disk, and the head was entirely sought for 200 hours at 3600 rotations. The area was measured by observing the end surface of the head outflow end after the seek with an optical microscope to quantify the amount of lubricant deposited. Was obtained, and the film thickness calculated from the interference fringes was multiplied to obtain the amount of lubricant deposited.

As a result, almost no adhesion of the lubricant was observed up to the flying height of 30 (nm), but 10 (n
In m), it can be seen that lubricant transfer / deposition cannot be avoided.

Based on these results, FIG. 3 shows the results of investigating the suction force after seek of Example 1 shown in FIG. 1, Example 2 and Comparative Example. The test disk / seek conditions were the same as those for the investigation of the lubricant deposition amount, and the maximum static friction force as the adsorption force was measured after the head after seek was left in the CSS area for 12 hours.

From these results, it is understood that the increase in the suction force due to the lubricant transferred / deposited on the head and sneaking into the ABS surface by leaving it after the apparatus is stopped depends on the area of the rear ABS part. . From FIG. 3, the outflow end flying height of the front ABS portion is 30 (nm), and the outflow end flying height of the rear ABS portion is 10
(Nm), the area of the rear ABS part is 0.02 (mm
² ) The area of the rear ABS part is 0 (mm ² ) by making it below.
It becomes the same level as the adsorption force at.

This means that at the outflow end of the front ABS part,
No transfer / deposition of lubricant (confirmed by observation after the test)
Therefore, even if the head ABS is contacted with the magnetic disk when the apparatus is left after stopping after the seek, it is shown that the head is not attracted by the lubricant in the front ABS.

As a confirmation of the effect of the flying height of the front ABS portion, the rear ABS portion area of Example 1 was 0.02 (mm ² ).
Of the outflow end of the front ABS part by load, 10, 15, 20, 25, 28, 30, 32, 3
FIG. 4 shows the result of investigation of the suction force after the seek for the head changed to 5, 40, 45 (nm). Regarding the measurement and the like, the same conditions as in the survey of FIG. 3 were used.

From this, the outflow end flying height of the front ABS part is set to 3
By setting it to 0 (nm) or more, it is possible to prevent an increase in adsorption force.

[Brief description of drawings]

FIG. 1 is a magnetic head of the present invention.

FIG. 2 is a lubricant deposition amount with respect to a head flying height.

FIG. 3 is a diagram showing a change in adsorption force with respect to an area of a rear ABS part.

FIG. 4 is a change in the suction force with respect to the floating amount at the outflow end of the front ABS portion.

[Explanation of symbols]

1 ... front ABS section, 2 ... rear ABS section, 3 ... front ABS section
Part outflow end, 4 ... Rear ABS part outflow end.

Claims (3)

[Claims] 1. In a head of a type in which an air bearing surface (ABS surface) is separated into a front portion and a rear portion, an area of a rear ABS surface (element portion) of a slider is 0.02 (mm ² ) or less, and A magnetic head having a flying height of 30 (nm) or more at the outflow end of the partial air bearing surface. 2. The magnetic head according to claim 1, wherein the flying height of the outflow end of the rear air bearing surface is 10 (nm) or less. 3. A magnetic disk device incorporating the magnetic head having the structure according to claim 1.