JP2801380B2 - Floating magnetic head for magneto-optical recording and magneto-optical recording device - Google Patents

Description

The present invention relates to a flying magnetic head for a magneto-optical recording medium.

[Related Art] In recent years, a magneto-optical recording device of a magnetic field modulation type has been proposed as a recording device capable of recording a large amount of information and rewriting an information signal at a high speed by overwriting (overwriting). In this method, a laser beam is radiated from one side of a disk and irradiated, and from the other side, a magnetic field modulated by an information signal is applied to erase old information and record new information.

If the magnetic head for generating a magnetic field used in this method has a large inductance, it is difficult to perform high-speed modulation. Therefore, it is necessary to reduce the inductance of the magnetic head. However, when a magnetic head having a small inductance is used, the generated magnetic field is small and the range over which the magnetic field extends is narrow, so that it is necessary to approach a magneto-optical disk as a recording medium.

For this reason, in general, air-floating magnetic heads (floating magnetic heads) are often used. An example of a method of fabricating such a structure of the flying magnetic head H will be described with reference to FIG. The levitation magnetic head H includes a levitation slider S made of a non-magnetic material, for example, a ceramic, a high-permeability magnetic material, for example,
A U-shaped magnetic core C made of Mn-Zn ferrite;
It is composed of a winding W wound around the magnetic core C.

First, a groove P1 for winding is provided on the floating slider S,
A groove P3 for reducing the weight of the groove P2 for arranging the magnetic core C is machined in FIG. 8 (a). Next, the magnetic core C is disposed in the groove P2 such that its open end is exposed on the bottom surface R side of the flying slider S, and is fixed by the glass G. The inflow temperature of the glass G is 500-600 ° C. After the magnetic core C is fixed, the bottom surface R of the flying slider S is mirror-polished (FIG. 8B).

Finally, the winding W is wound around one leg of the magnetic core C.
By supplying a current to the winding W, a magnetic field as shown by B in the drawing is generated from the open end of the magnetic core C (FIG. 8C).

Next, the overall configuration of the magneto-optical recording device will be described with reference to FIG.

D is a magneto-optical disk, which is rotated at high speed by a motor M. Magnetic head H levitating between disk D
And the optical head P are opposed to each other. The optical head P focuses a laser beam on the magnetic recording layer of the disk D and irradiates the laser beam to partially heat it. On the other hand, the levitation magnetic head H is supported by the suspension SUS, and the levitation slider S obtains buoyancy by the air flow accompanying the rotation of the disk D, thereby causing the disk D to rotate.
2 to 3 μm above the surface of the sample. In this state, when the current modulated by the information signal is supplied from the drive circuit DR to the winding W, a vertical magnetic field modulated by the information signal is generated on the magnetic recording layer of the disk D from the open end of the magnetic core C. I do. In a portion of the magnetic recording layer heated by the laser beam, magnetization corresponding to the applied perpendicular magnetic field remains, and information signal recording is performed.

[Problem to be Solved by the Invention] In the conventional method for manufacturing a floating magnetic head H, the step of applying a winding as shown in FIG. Same as case.
This is because the inflow temperature of the glass G is 500-600 ° C. in the glass bonding process shown in FIG. 8 (b), which is much higher than the heat-resistant temperature of the winding W of 150 ° C. FIG. This must be done after the glass bonding step shown in FIG. 8 (b). However, such a toroidal winding has a problem in that the work efficiency is poor and automation by an automatic winding machine is difficult as compared with a case where the winding is performed on a solenoid winding, that is, a rod-shaped core.

In addition, the step of mirror-polishing the bottom surface F of the flying slider S must be performed after glass bonding in order to make it flush with the magnetic core C and the bottom surface R of the glass G. In order to prevent breakage due to the mechanical force applied to the surface, the upper surface R, which is a plane parallel to the bottom surface F and having a sufficient area, is required. For this purpose, the thickness of the flying slider S must be greater than the height of the magnetic core C. The height of the magnetic core C is related to the magnetic field generation efficiency, and needs to be 1.5 mm or more. Therefore, the thickness of the flying slider S needs to be 1.5 mm or more. Even if the groove P3 is provided at the center of the flying slider S as shown in the figure, the weight is large and the dynamic mechanical characteristics of the flying magnetic head H deteriorate. Cause. For this reason,
The levitation magnetic head comes into contact with the disk D due to the vibration applied from the outside, so it is easy to generate a head crash,
This increases the risk of scratching the surface of the disk D.

[Means for Solving the Problems] The problem with the conventional floating magnetic head for magneto-optical recording as described above is that the manufacturing process is performed by bonding a magnetic core to a floating slider by glass bonding → mirror polishing of the floating slider → magnetic processing. The reason is that winding is performed in the order of winding on the core.

Therefore, the present invention provides a floating magnetic head that can be manufactured by a process of bonding a magnetic core with a winding to a floating slider after mirror polishing,
An object of the present invention is to solve all the problems of the conventional flying magnetic head for magneto-optical recording.

[Example] FIGS. 1 (a), 1 (b) and 1 (c) show the manufacturing steps of a floating magnetic head for magneto-optical recording according to the present invention, and FIGS.

S is a floating slider, which is a non-magnetic ceramic substrate having a thickness of 0.2 to 0.5 mm (FIG. 1A). The floating slider S has a groove P formed in a part of the upper surface R, and the bottom surface F is mirror-polished. At this time, the bottom of the groove P is parallel to the bottom surface F of the flying slider S, and the interval is 100 μm or less, preferably 7 μm or more and 67 μm or less. First
FIG. (B) Next, a single U-shaped magnetic core C made of a high-permeability magnetic material, for example, Mn-Zn ferrite,
A winding provided with windings W of 20 to 30 turns is installed so that its open end face is in close contact with the bottom of the groove P, and is fixed with an adhesive E. FIG. 1 (c) The floating magnetic head H for magneto-optical recording according to the present invention differs from the conventional example in that the open end face of the magnetic core C is not flush with the bottom face F of the flying slider S.
It is located below the bottom face F with an interval of less than μm, which is an effective means for making the intensity distribution of the magnetic field applied to the magneto-optical disc D as a recording medium uniform.

This will be described with reference to FIG. Generally, the size of the open end face of the magnetic core C is Is used, the horizontal direction to the end face is x, the vertical direction is y, the center of the end face is x = o, y = o, and the generated magnetic field intensity distribution is graphed below. Although it is actually used between -0.1 and +0.1 mm in the x direction, the graph shows only the + direction since it can be regarded as a target with x = o as the center. As shown, when y = 10 μm, o
In the range of x0.1, the magnetic field intensity has a spread of 100% ± 35%, whereas when y = 20 μm to y = 80 μm, the spread is each ± 25% or less. In practice, the spread of the magnetic field strength is ± 25
%, It is better to set the use range to 20 μm 80 μm in the y direction. Actually, this spread is ± 25% or less even when y is 100 μm, but is not suitable for practical use because the generated magnetic field strength is reduced.
This graph relatively shows the difference in the generated magnetic field strength in the x direction, but cannot compare the difference in the generated magnetic field strength in the y direction.

More general When using a magnetic core having an open end surface, the distance from the end surface to the magnetic recording layer of the magneto-optical disk is 20 μm to 80 μm.
m, but a protective film is provided on the magnetic recording layer of the magneto-optical disk, and its thickness is generally 10 μm.
m, and the flying height of the flying slider is 3 μm, it is desirable that the distance between the bottom face F of the flying slider S and the open end face of the magnetic core C be 7 μm to 67 μm.

Next, the second floating magnetic head for magneto-optical recording according to the present invention will be described.
The embodiment will be described with reference to FIG. In this embodiment, the magnetic core C is of a pot type, and the winding W
Is provided. The center pole tip surface is the groove P of the floating slider S
It is arranged so that it may be in close contact with the bottom of the. Such a pot-shaped magnetic core C has a magnetic field generation efficiency of 5 to 10% better than the "-" shaped magnetic core shown in the first embodiment or the conventional example. That is, if the windings W are the same, a sufficient generated magnetic field strength can be obtained even if the current is reduced by 5 to 10%.

Next, the third floating magnetic head for magneto-optical recording according to the present invention will be described.
The embodiment will be described with reference to FIG. In this embodiment, a substrate Pl made of a high magnetic permeability material such as ferrite is used as a magnetic core for generating a modulation magnetic field, and a spiral thin film conductor pattern cu (for example, a copper thin film) is formed as a winding on the surface thereof. Use something. The use of the thin film conductor as the winding is advantageous because the loss at a high frequency can be reduced as compared with the other embodiments. The substrate Pl is arranged so that the conductor pattern cu side is at the bottom of the groove P of the flying slider S. In this case, the open end of the magnetic core is located substantially near the center of the linear conductor pattern cu even on the surface of the substrate Pl.

Next, an embodiment of a magneto-optical recording device using the magneto-optical recording flying head according to the present invention will be described.

FIG. 6 shows the entire configuration of the magneto-optical recording device. Where P
Is an optical head, D is a magneto-optical disk which is a magneto-optical recording medium, M is a drive motor for rotating the disk D at high speed,
SUS is a suspension for holding the flying magnetic head H. The disk D is composed of a glass or plastic substrate SUB, a magnetic recording layer MAG, and a protective film PC having a thickness of about 10 μm.

When an information signal is recorded on the disk D, the flying magnetic head H is 10 μm or less, for example, 3 μm between the magnetic head H and the surface of the disk D.
The levitation traveling is performed with the interval of μm. By supplying a current modulated by the information signal to the winding W from the drive circuit DR, a magnetic field B that changes by the information signal is applied from the open end face of the magnetic core C almost perpendicularly to the disk D.

On the other hand, the laser beam L from the optical head P is
Irradiation is performed so as to have a diameter of about 1 μm. In the magnetic recording layer MAG, the temperature rises due to the irradiation of the laser beam L,
Magnetization is generated in accordance with the magnetic field B applied from the flying magnetic head H, passes through the portion irradiated with the laser beam, and the magnetization is preserved as the temperature decreases. Thus, the magnetic recording layer MA
The information signal is recorded by forming a pattern of the magnetized region in G.

FIG. 7 is a view showing another embodiment of the magneto-optical head according to the present invention. Both legs of the magnetic core C are inserted into separately formed grooves P and fixed with an adhesive E.

The mounting direction of the magnetic core C is different from the example shown in FIG. 2, but the effect is the same.

[Effects of the Invention] As described above, the floating magnetic head according to the present invention is a process of bonding the magnetic core after winding to the slider after the groove processing of the floating slider and the mirror polishing of the bottom surface. Therefore, the following effects can be obtained. First, when winding the magnetic core, the winding is not a toroidal winding but a solenoid winding, so that the work efficiency is high and automation by an automatic winding machine can be easily performed. It is also possible to use a method of inserting the formed winding (coil) into the magnetic core.

Second, it is not necessary to make the thickness of the flying slider more than the height of the magnetic core.
It is possible to reduce the weight of the flying magnetic head, improve the dynamic mechanical properties, and prevent the disk surface from being damaged by the head crash.

Third, as shown in the second and third embodiments, efficient magnetic field generation by a high-efficiency pot-type magnetic core, which cannot be used in the conventional process, and loss of high-frequency loss having a thin film conductor pattern. It is possible to employ a small magnetic core.

Fourth, the distance between the bottom surface of the flying slider and the open end surface of the magnetic core is set to 100 μm or less, preferably 7 μm or more, and 67 μm or less to make the magnetic field intensity distribution uniform and achieve good signal recording. It can be made possible.

[Brief description of the drawings]

FIG. 1 is a view showing a process of manufacturing a levitation magnetic head according to the present invention, FIG. 2 is a sketch of a levitation magnetic head according to the present invention, FIG. 3 is a view showing a generated magnetic field distribution of a levitation magnetic head according to the present invention, FIG. 4 is a view showing a second embodiment of the flying magnetic head according to the present invention, FIG. 5 is a view showing a third embodiment of the flying magnetic head according to the present invention, and FIG. 6 is a magneto-optical recording of the present invention. FIG. 7 is a view showing the overall configuration of the apparatus, FIG. 7 is a view showing another embodiment of the floating magnetic head according to the present invention, FIG. 8 is a view showing a manufacturing process of a conventional floating magnetic head, FIG. 9 is magneto-optical recording FIG. 2 is a diagram illustrating an entire configuration of the device. S: Floating slider C: Magnetic core W: Winding F: Floating slider bottom surface R: Floating slider upper surface P: Groove

Claims (3)

(57) [Claims] 1. A floating magnetic head as a magnetic field applying means of a magneto-optical recording apparatus for recording an information signal by applying a modulation magnetic field to a magneto-optical recording medium comprises a plate-shaped floating slider made of a non-magnetic material, A magnetic core made of a magnetic permeability material;
And a winding wound around the magnetic core. The concave portion for mounting the magnetic core or the shelf portion on the upper surface of the floating slider has a bottom portion substantially parallel to the bottom surface of the floating slider and an interval between them is 100 μm or less. And the step of fixing the magnetic core to the concave portion or the shelf after the winding is wound, the bottom surface of the floating slider and the open end of the magnetic core. A floating magnetic head for magneto-optical recording, characterized in that the end faces are parallel to each other and the distance between them is 100 μm or less. 2. A floating magnetic head as a magnetic field applying means of a magneto-optical recording apparatus for recording an information signal by applying a modulating magnetic field to a magneto-optical recording medium is provided with a plate-shaped floating slider made of a non-magnetic material. A magnetic core made of a magnetic permeability material;
A step of mirror-polishing the bottom surface of the floating slider, a concave portion or a shelf for mounting the magnetic core on the upper surface of the floating slider, and the bottom portion of the bottom surface of the floating slider. After the step of forming the magnetic core so as to be substantially parallel to and having an interval of 100 μm or less, the magnetic core is fixed to the concave portion or the shelf portion. The open end face of the core is parallel and the interval is 10
A floating magnetic head for magneto-optical recording, wherein the magnetic head has a thickness of 0 μm or less. 3. A flying magnetic head as a magnetic field applying means of a magneto-optical recording apparatus for recording an information signal by applying a modulation magnetic field to a magneto-optical recording medium according to claim 1 or 2. A magneto-optical recording device, characterized in that: