JPH10222834A - Magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a negative pressure head with less adhesion of dust in the vicinity of a step of a negative pressure part, hardly causing a head crash caused by dust and with high reliability by forming a joint part between at least a part of a wall surface among the wall surfaces making boundaries of a negative pressure groove formed on a magnetic disk opposing surface and a negative pressure groove bottom surface with a curved surface. SOLUTION: The joint part between at least one part of the wall surface 3d among the wall surfaces making the boundaries of the negative pressure groove 3c formed on the magnetic disk opposing surface and the negative pressure groove 3c bottom surface is formed by the curved surface. When air flowing to the magnetic disk opposing surface of the negative pressure head flows from a positive pressure generation part 3b to the negative pressure groove 3c, the pressure of the air in the negative pressure groove 3c becomes low by its step. Thus, force drawing a slider close to the magnetic disk is caused. By making the joint part between the negative pressure groove 3c bottom surface and the wall surface the curved surface, the head without the adhesion of dust is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used for a magnetic recording device mounted on a computer or the like.
In particular, the present invention relates to a magnetic head having improved reliability against sliding with a magnetic recording medium.

[0002]

2. Description of the Related Art A magnetic disk drive used in a computer employs a system in which a magnetic head floats using a viscous flow generated near the surface of a magnetic disk as the magnetic disk serving as a magnetic recording medium rotates. FIG. 4 shows an example of a flying magnetic head. The magnetic head 1 has a structure in which an electromagnetic transducer 2 is fixed to a slider 3, and the slider 3 is fixed to a spring arm 5 via a gimbal 4. The spring arm 5 is driven by a voice coil motor or the like (not shown) to control the position of the head. The slider surface of the magnetic head is pressed against a magnetic disk (omitted in the drawing) by a force of a spring arm, and both are in contact when the magnetic disk is not rotating. Here, when the magnetic disk rotates, an air flow is generated in the vicinity of the magnetic disk surface, and the air flow acts on the slider surface, so that the magnetic head flies above the magnetic disk surface. From the viewpoint of the recording / reproducing characteristics of the magnetic head, the smaller the flying height, the better, and it is important to ensure a stable low flying height.

In recent years, a floating head (negative pressure head) utilizing negative pressure has been often used in order to secure a stable flying height. An example of the negative pressure head is a head having a structure as shown in FIG. The air flow generated by the rotation of the magnetic disk flows from the step portion 3a on the air bearing surface side of the slider to the negative pressure groove 3c for generating a negative pressure via the positive pressure generating portion 3b. At this time, when the air passes through the step forming the negative pressure groove 3c, the air expands from a compressed state, and a region having a low atmospheric pressure is created in the negative pressure groove 3c. This negative pressure generates a force to attract the slider 3 toward the magnetic disk. Therefore, the slider 3 has a force for floating the magnetic head due to a floating force generated in the positive pressure generating portion 3b, and a suction force generated in the negative pressure groove 3c.
Three forces of the pressing force of the spring arm 5 act, and low levitation is realized by the balance of these three forces. Generally, the negative pressure groove 3c is often formed by milling, and a surface (hereinafter, referred to as a wall surface in the present specification) connecting the positive pressure generating portion and the bottom of the negative pressure groove is formed at a certain angle on the bottom surface of the negative pressure groove. They are in contact with each other and have not been specially designed to be curved.

[0004]

However, this negative pressure head has a problem that dust such as abrasion powder of a protective film of a magnetic disk tends to accumulate in the vicinity of a step of a negative pressure groove which generates a suction force. Dust easily accumulates in specific places where the pressure is low. May be.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a highly reliable negative pressure head in which dust adheres little in the vicinity of a step of a negative pressure part, so that a head crash caused by the attached dust is less likely to occur. is there.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for joining at least one of the walls forming the boundary of a negative pressure groove formed on a surface facing a magnetic disk with the bottom surface of the negative pressure groove. This is achieved by forming the part with a curved surface.

When the air flowing on the magnetic disk facing surface of the negative pressure head flows from the positive pressure generating surface 3b to the negative pressure groove 3c, the pressure of the air in the negative pressure groove 3c decreases due to the level difference, and the slider draws the slider to the magnetic disk. Is generated. Here, the generated negative pressure differs depending on the shape of the wall surface 3d forming the step. In general, the more abrupt steps are generated, the greater the negative pressure is generated. However, there is a problem that dust easily accumulates near the contact between the bottom surface and the wall surface of the negative pressure groove. In the present invention, a head free from dust is obtained by making the tangent line between the bottom surface and the wall surface a curved surface.

In the generation of a negative pressure, a step near a portion close to a positive pressure generating surface is particularly important. The steeper the step, the greater the effect of generating a negative pressure. On the other hand, the problem with the adhesion of dust is near the junction between the bottom surface and the wall surface of the negative pressure groove. If the angle between the bottom surface and the wall surface is small, the dust does not adhere. As a method of satisfying these two conditions, there is a method of forming a curved surface between a wall surface and a bottom surface. That is, as shown in the claims of the present specification, the wall surface in contact with the positive pressure generating surface is a plane having a steep slope to some extent, and the junction with the bottom surface is a curved surface, thereby preventing the adhesion of dust. . Here, the angle of the wall surface does not necessarily need to be perpendicular to the slider surface, and the curved surface connecting them does not need to be a perfect cylindrical surface. In addition, the target wall surface is particularly effective for a surface perpendicular to the flow of air involved in generation of a negative pressure, but may be applied to some wall surfaces or all wall surfaces. .

In the present invention, since the bottom of the negative pressure groove and the wall surface are connected by a gentle curved surface, the occurrence of turbulence such as reflux near the wall surface of the bottom surface is suppressed. Generally, sediment easily accumulates in areas where convection occurs, and dust adheres to the vicinity of the boundary between the bottom surface and the wall surface with conventional negative pressure sliders. Was sometimes Therefore, by connecting the bottom surface of the negative pressure groove and the wall surface with a curved surface, dust does not adhere to the bottom surface, and it is possible to prevent a crash caused by the attached dust.

As described above, according to the present invention, the wall connecting the negative pressure groove and the positive pressure generating portion has a sufficiently steep angle with respect to the positive pressure generating surface, and functions sufficiently as a step for generating a negative pressure. In addition, since there is no dust attached, both high reliability and a stable flying height can be achieved.

[0011]

Embodiments of the present invention will be described below. (Example) As shown in FIG.
% Milled by a milling method. After a certain mask material was patterned to obtain a mask having a thickness of 10 μm, heat treatment was performed under certain conditions. Although the mask material shrinks by this heat treatment, since the lower surface of the mask material is fixed to the substrate, a mask having a curved end surface as shown in FIG. 2A is obtained. When milling is performed with this mask, the portion of the negative pressure groove of the slider is processed, and the mask is also gradually removed to obtain the shape shown by 6b. Therefore, during processing, the mask is
, And the newly exposed slider material is sequentially processed with the retreat of the mask. Therefore, according to this processing process, the wall surface is constituted by a curved surface, and the wall shape shown in the claims of the present invention can be realized. This curved surface can be controlled mainly by heat treatment conditions and selection of a mask material. When the obtained sample was examined with an optical surface shape evaluation device, it was found that the wall had a curved surface at the joint with the bottom surface of the negative pressure groove as shown in FIG. After milling, the slider surface was finished by lapping, and finally a 5 nm-thick carbon protective film was formed on the slider surface using a DC magnetron sputtering device. After sputtering, the slider was loaded with a spring load of 3.5.
gf suspension.

A slider material patterned with a mask similar to that of the first embodiment was milled without applying any special heat treatment. At this time, processing was performed so that dimensions other than the intersection angle, such as the depth of the negative pressure groove, were the same as those in Example 1. When the angle of the wall surface was measured by an optical surface shape measuring instrument, FIG.
It was found that the intersection angle was about 80 degrees as shown in FIG. After milling, lapping was performed under the same conditions as in Example 1 to form a carbon film. Attached to the suspension. The spring load was 3.6 gf.

The evaluation was performed based on the evaluation of the flying height for evaluating the effect of the negative pressure and the presence / absence of a substance adhering to the slider surface after performing 50,000 times of CSS. The flying height was evaluated based on a value actually measured by a dynamic flying height tester manufactured by Phasemetric. The CSS test was performed in an environment at a temperature of 30 degrees Celsius and a relative humidity of 80%. The disk used for the test was 95 mm in diameter and 15 nm as a protective film.
And a lubricant of about 1.5 nm is applied to the surface.

Table 1 shows measured values of the flying height of each head. The measurement was performed with a peripheral speed of 18.5 m / sec and a skew angle of 10 degrees, and the flying height near the electromagnetic transducer was examined. Each of them shows almost the same flying height, and there is no influence on the flying height due to the curved surface of the joint between the wall surface and the bottom surface. Table 1 also shows the results of checking for the presence of dust adhering to the head surface after 50,000 CSS runs. No dust or other deposits were found on the slider surface after the test for the head of the example, whereas the head of the comparative example protected the magnetic disk near the tangent between the bottom surface of the negative pressure groove and the wall after the test. It was observed that dust which appeared to be carbon, which was a film, was attached.

[0015]

[Table 1] From the above results, it is possible to obtain a magnetic head that can withstand long-term use without dust adhesion even after performing a lot of CSS by making the joint between the wall surface of the negative pressure head and the bottom surface of the negative pressure groove a curved surface. I knew it could be done.

[0016]

According to the present invention, a magnetic head free of dust can be obtained, and a magnetic head having high reliability and durability can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an example of the present invention.
FIG.

FIG. 2 is a diagram illustrating an embodiment of the present invention.

FIG. 3 is a diagram showing shapes of an example of the present invention and a comparative example.

FIG. 4 is a side view schematically showing an example of a magnetic head.

FIG. 5 is a perspective view of a negative pressure type magnetic head slider.

[Explanation of symbols]

Reference Signs List 1 magnetic head, 2 electromagnetic transducer, 3 magnetic head slider, 3a step section, 3b positive pressure generating section, 3c
Negative pressure groove, 4 gimbals, 5 spring arms, 6 mask material

Claims (1)

[Claims] 1. A magnetic head having a groove for generating a negative pressure, comprising a wall surface and a bottom surface forming a step on a slider surface facing a magnetic disk, and joining at least a part of the wall surface to the bottom surface of the groove. A magnetic head, wherein the portion is formed of a curved surface.