JPH01146119A - Composite floating magnetic head - Google Patents

Abstract

PURPOSE:To produce a composite floating magnetic head superior in CSS (contact start stop) durability by rounding a floating face on the air outflow side of a slider with >=100mum radius of curvature. CONSTITUTION:A core chip 2 which has a magnetic gap 4 and consists of an Mn-Zn ferrite is unified with a slider 1 consisting of a calcium titanate by glass bonding. An air outflow end 5 is rounded in a range except the magnetic gap 4 with >=100mum radius of curvature by tape lapping. Thus, the angle formed between the floating magnetic head and a recording medium, namely, a pitch angle 7 is widened, and as the result, the effective time of contacting between the floating face of the magnetic head and the recording medium at the time of CSS is considerably shortened to prevent physical degradation of the magnetic head and the recording medium due to CSS.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the shape of a floating magnetic head used in a fixed magnetic disk drive.

[Conventional technology]

The shape of the slider of a conventional floating magnetic head was developed in Japanese Patent Application Laid-open No. 5
As in No. 0-104918, a chamfer of 20 degrees or more was provided on the air outflow side in order to reduce the adhesion of dust or to prevent the slider from chipping.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional technology, when a thin film recording medium with low magnetic film strength is used or the flying height of the floating magnetic head is low, the magnetic head is kept in contact with the disk and the disk is started or stopped. The so-called C
Repeating 3S (contact start and stop) causes problems such as physical deterioration of the magnetic head and recording medium and head crash.

The present invention is intended to solve these problems, and its purpose is to provide a composite floating magnetic head with excellent C8S durability.

[Means for solving problems]

The composite floating magnetic head of the present invention is characterized in that the floating surface on the air outflow side of the slider has a radius of curvature of at least 100 μm or more.

[For production]

According to the above configuration of the present invention, the angle formed between the floating magnetic head and the recording medium, that is, the pitch angle, becomes large, and as a result, the effective time during which the floating surface of the magnetic head and the recording medium are in contact during CSS is significantly shortened.

Therefore, physical deterioration of the magnetic head and recording medium due to C8S can be prevented. However, if the radius of curvature is less than 100 μm, the negative pressure generated becomes small and the above effect disappears.

〔Example〕

FIG. 1 is a perspective view of a composite floating magnetic head in an embodiment of the present invention. As shown in FIG. 1, for example, after a core chip 2 made of Mn-Zn ferrite having a magnetic gap 4 is integrated with a slider 1 made of calcium titanate by glass bonding, a magnetic A radius 3 with a radius of curvature of at least 100 μm or more is formed by tape wrapping within a range that does not overlap the gap 4.

FIG. 2 shows the flying posture of the composite type floating magnetic head shown in FIG. 1. As the recording medium 8 rotates in the direction of the arrow 9, the slider 1 flies. The flying height 10 is expressed by the distance between the magnetic gap 4 and the recording medium 8.

FIG. 3 shows the relationship between the pinch angle 8 and the radius of curvature of the radius. However, the flying height at this time is 0.2 when the relative speed between the slider 1 and the recording medium 8 is 9 m/s.
It is 0 μm. From FIG. 3, it can be seen that the larger the radius of curvature of the radius, the larger the pitch angle becomes. this is,
This is because negative pressure is generated in the slider due to the radius. This effect is particularly significant when the radius of curvature is 100 μm or more.

By having a flying attitude with a large pitch angle, CSS
At times, the time during which the floating surface and the recording medium are in contact can be significantly shortened, improving C8S durability.

FIG. 4 shows the relationship between relative speed and pitch angle in a magnetic head in which the radius of curvature of the radius is 150 μm and the flying height is 0.25 μm at each relative speed. From FIG. 4, when the flying height is fixed, the smaller the relative velocity, the smaller the pitch angle. This is because when the relative speed is small, the negative pressure generated in the chamfer becomes small.

Furthermore, it can be seen that when the relative speed is small, in order to increase the pitch angle for the purpose of improving C8S durability, the radius of curvature of the radius must be increased.

From the above, in order to improve C8S durability by utilizing the negative pressure generated in the radius, the radius of curvature of the radius must be 100 μm or more, and the radius of curvature is determined by the flying height and relative speed. , the size of the magnetic head, etc. By the way, the radius of curvature provided on the air outflow end may have a plurality of radii of curvature, but the radius of curvature of the radius of curvature of the radius that is continuous with the floating surface needs to be 100 μm or more.

Actually, the relative speed was 8.0m/s, and the flying height was 0.20μ.
CSS was performed 30,000 times, and Table 1 shows the results of the appearance of the recording medium and the coefficient of friction.

The C8S test is one of the important items related to the reliability of fixed magnetic disk drives.The appearance of the recording medium means the maintainability and reproducibility of data, and the coefficient of friction is a measure of the motor driving the recording medium. It is related to torque, and if the coefficient of friction is large, the recording medium will not rotate. The allowable friction coefficient for a fixed magnetic disk device varies depending on the number of recording media used and the torque of the motor used, but -M
is required to be 0.8 or less.

The recording medium used was a plating thin film recording medium, each coated with 100 Cr/C as a lubricating film.

Table 1. As is clear from Table 1, the results after 3,320,000 C cycles, the composite floating magnetic head according to the present invention showed a sufficient improvement in CSS durability, and this effect was also confirmed in actual experiments.

[Effects of the Invention] As described above, according to the present invention, by providing a radius of curvature of at least 100 μm on the floating surface on the air outflow end side of the composite magnetic head, excellent CSS durability and reliability can be achieved. A composite floating magnetic head with high performance can be obtained. In particular, it has the effect of being able to sufficiently cope with the thinning of the recording medium, the lowering of the flying height of the magnetic head, and the reduction of relative speed in the case of increasing recording density.

Further, by providing a radius on the air outflow side, the flying height between the magnetic gap and the disk, which most affects the recording density, is reduced.

Since the magnetic head of the present invention also utilizes negative pressure, it also has the effect of providing a stable flying posture.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the present invention. FIG. 2 is a sectional view showing the flying posture of the magnetic head of the present invention. FIG. 3 is a diagram showing the relationship between the pitch angle and the radius of curvature of the radius. FIG. 4 is a diagram showing the relationship between relative speed and pitch angle. 1...Slider 2...Core chip 3...Round 4...Magnetic gap 5...Air outflow end 6...Floating surface 7...Pitch angle 8...Recording medium 9... Recording medium rotation direction 10...Flying height or more Applicant Seiko Epson Corporation 1st country 2 units

Claims (1)

[Claims] In a composite type floating magnetic head that performs recording and reproduction while floating above a magnetic recording medium, and in which a core chip is embedded in a slider made of ceramics, a radius of curvature of at least 100 μm or more is formed on the floating surface on the air outflow side of the slider. A composite floating magnetic head characterized by having.