JPH02232816A - Magnetic disk - Google Patents

Abstract

PURPOSE:To prevent attraction without degrading a magnetic converting characteristic by providing a storing area, which has prescribed surface roughness, and a guard band area having the rougher surface than that of the storing area. CONSTITUTION:The surface roughness of a storing area 4 in a magnetic disk 1, which is composed of a magnetic film 2 and a base 3, is almost less than Rmax100Angstrom in a measure not to affect the magnetic converting characteristic. Width (a) of the storing area preferably equals to the width (w) of the tip of the magnetic head. The surface roughness of a guard band area 5 is almost more than 200-300Angstrom in a size to prevent the attraction and it is preferable to determine the width (b) according to the need of the whole magnetic disk system.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a magnetic disk mounted in a magnetic disk device. [Prior Art] A fixed magnetic disk device, which is one of the external storage devices of a computer, is mainly composed of a magnetic disk and a magnetic head slider, and a configuration diagram thereof is shown in FIG. This is, for example, a publication {Journal of the Japanese Society of Applied Magnetics VOL. 11
．． No. 1.1987}. In the figure, (1) is a magnetic disk, and (6) is a magnetic disk (1).
The magnetic head slider (8) is a suspension that presses the magnetic head slider (6) against the magnetic disk (1). (9) is a spindle that rotates the magnetic disk (1) in the direction of the arrow in the figure. In the magnetic disk device configured as described above, when writing or reading information to or from the magnetic disk (1), the magnetic disk (1) is rotated at high speed 11i (for example, 3600 rpm) in the direction of the arrow. The airflow generated by this circular signal causes the magnetic head slider (6) to float above the surface of the magnetic disk (1) with a submicron gap, using the principle of air bearing. That is, suspension (
The magnetic head slider (6) floats stably by balancing the pushing force of 8) with the upward force of the air flow. On the other hand, when the magnetic disk drive is not used, the spindle (9) stops rotating and the magnetic head slider (6) is pressed by the suspension (8) and comes into contact with the magnetic disk (1). 9 and 10 are enlarged views of the vicinity of the magnetic head slider in FIG. The figure shows when the magnetic disk is stopped (the magnetic disk is stationary).

Now, as the demand for higher density magnetic disk drives has increased in recent years, the flying gap of the magnetic head slider has been made smaller, and the roughness of the surface of the magnetic disk has also become smaller. However, if the surface roughness of the magnetic disk is too small, the magnetic head slider and the magnetic disk will stick together when the magnetic disk drive is stopped. Showa 62
As disclosed in Japanese Patent Publication No. 287419, a magnetic disk is processed to have an unevenness of R s s x 500 to 1000.

FIG. 11 is a partially enlarged configuration diagram of the vicinity of the magnetic head slider in FIG. 8, and in the figure (2)
is the magnetic film of the magnetic disk (1), (3) is the base material, (7)
is a magnetic head formed on a magnetic head slider. That is, leakage magnetic flux from the magnetic head (7) causes the magnetic film (2
) is recorded by magnetizing it, and magnetism II (2)
Reading is performed by capturing the leakage magnetic flux from the magnetic head (7). Fig. 12 is an enlarged perspective view seen from the direction of arrow A in Fig. 11, showing the case where information has already been written in the magnetic film (2) and is being read out. The part where information is written (magnetized part), (100) is the part where no information is written, the arrow (l1) is the direction of magnetic flux leaking from the magnetic film, and (W) is the width of the tip of the magnetic head. . In other words, the magnetized part of the magnetic film is called the recording area (a in the figure), and the non-magnetized area is called the guard band (b in the figure).A magnetic disk on which information is recorded over the entire surface extends from the inner circumference to the outer circumference of the magnetic disk surface. Areas a and b above are repeated. [Problems to be Solved by the Invention] However, although the above-mentioned conventional texture applied to the surface of a magnetic disk is effective in preventing adhesion, from the viewpoint of electromagnetic conversion characteristics, the unevenness of the texture reduces the magnetization of the magnetic film. Disturbances in direction and variations in the distance between the head tip and the disk occur, resulting in problems such as a decrease in output and an increase in noise. This invention was made to solve this problem, and the purpose is to obtain a magnetic disk that prevents adsorption without deteriorating the electromagnetic conversion characteristics. [Means for Solving the Problems] A magnetic disk of the present invention is provided with a recording area having a predetermined surface roughness and a guard band area having a surface roughness greater than the surface roughness of the recording area.

[Function] In this invention, the surface roughness of the recording area is small and the flat surface prevents disturbance of the magnetization direction of the magnetic film, and the distance between the head tip and the recording area surface is equal, so that the electro-a conversion characteristics are improved. Deterioration is prevented. On the other hand, since the guard band portion has a large roughness, it is possible to prevent the magnetic head slider from fully adhering to the magnetic disk when the disk is stopped. [Embodiment] Figure 1 is a new view of a magnetic disk according to an embodiment of the present invention. In the figure, (1) is a magnetic disk, (2) is a magnetic film, and (3) is a magnetic disk base material. ( 4) is a recording area with a predetermined surface roughness, and (5) is a guard band area with a larger surface roughness than recording area (4). It is repeated alternately from the inner circumference to the outer circumference.

The surface roughness of the recording area (4) according to the present invention is approximately R. ．． ．． I00 or less, and the radius a is preferably approximately equal to the width W of the tip of the magnetic head.

The surface roughness of the guard band region (5) according to the present invention is approximately R, . For 200 to 300 or more people, the width b is related to the recording density, so it is desirable to determine it based on the requirements of the entire device.

Fig. fJ2 is a block diagram showing a state in which recording and reading are performed on the magnetic disk according to the embodiment of the present invention, and the shaded area in the figure indicates that information is being recorded (magnetized). That is, the magnetic head slider (6) levitates the magnetic disk (1) by a minute distance, and the head (7) magnetizes (records) the magnetic film (2) or records the magnetic film (2).
2) Capture (read) the leakage magnetic flux from.
When recording, only the recording area (portion with small surface roughness) (4) shall be recorded. FIG. 3 is a partial cross-sectional configuration diagram showing the magnetic head slider in contact with the surface of the magnetic disk according to the embodiment of the present invention.

In this case, there may be a gap between the guard band (5) and the surface of the magnetic head slider, or the guard band (5) may
Since the slider surface rides on the convex portion of the magnetic disk, the slider surface does not come into complete contact with the magnetic disk surface, thereby preventing adsorption.

FIG. 4 is a sectional view of a magnetic disk according to another embodiment of the present invention. That is, in contrast to the above embodiment, in which the recording area (4) and the guard band (5) are formed, portions with small and large surface roughness are formed on the surface of the magnetic disk base material (3). This forms areas with small and large surface roughness on the magnetic film (2).

@Figures 5 and 6 are diagrams of magnetic disks according to other embodiments of the present invention. In other words, since no recording is made on the guard band, areas with large surface roughness (guard band)
(5) is the case where no magnetic film is present, and even if it is present, the thickness may be thin.

FIG. 7 is a sectional view of a magnetic disk according to still another embodiment of the present invention. That is, since no recording is made on the guard band, the portion (guard band) (5) with large surface roughness is formed of a material different from that of the magnetic film (2). In addition, this invention deals with the problem of roughness in that the surface roughness of the area that should be the recording area on the magnetic disk is small, and the surface roughness of the area that should be the guard band is large. There are no restrictions on the relationship between band heights. For example, the heights of the recording area and the guard band may or may not be the same as shown in Figure Ill. Furthermore, there are no restrictions on the method of controlling the roughness; any method such as grooves, undulations, or protrusions may be used, and no restrictions are placed on the shape. [Effects of the Invention] As explained above, the present invention has a recording area with a predetermined surface roughness and a guard band area with a surface roughness greater than the surface roughness of this recording area.
It is possible to obtain a magnetic disk that prevents adsorption without deteriorating electromagnetic conversion characteristics.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a magnetic disk according to an embodiment of the present invention.
FIG. 2 is a configuration diagram showing a state in which writing and reading are performed on a magnetic disk according to an embodiment of the present invention, and FIG. A partial new Wi configuration diagram showing a state in which the slider is in contact, FIGS. 4 to 6 are diagrams of a magnetic disk according to another embodiment of the present invention, and FIG. II7 is a magnetic disk diagram according to another embodiment of the present invention A top view of a disk, FIG. 8 is a configuration diagram of a conventional magnetic disk device, FIGS. 9 and 10 are enlarged configuration diagrams of the vicinity of the magnetic head slider in FIG. 8, and FIG. 11 is a diagram of the magnetic head in FIG. 8. Figure 12 is a partially enlarged view of the area around the slider. 11 is a perspective view seen from the direction of arrow A in FIG. 11. In the figure, (1) is a magnetic disk. (2) is a magnetic film,
(3) is a magnetic disk base material 5 (4) is a recording area, (5)
is a guard band. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] A magnetic disk comprising a recording area with a predetermined surface roughness and a guard band area with a surface roughness greater than the surface roughness of the recording area.