JPH06243418A - Laminate type magnetic head - Google Patents

Abstract

PURPOSE:To control the effect of noises due to external disturbance as well as to reduce inductance and to provide a laminate type magnetic head which can be produced at a low cost. CONSTITUTION:Laminated films each consisting of superposed magnetic films and insulating films are bonded with a gap 2 in-between to form a magnetic core 1 and the laminated films forming this magnetic core 1 are partially disposed on both sides of the gap 2 on a side face of a slider 21. Since the area of the magnetic core 1 becomes smaller than the total area of the side faces of the slider 21, a high efficiency magnetic circuit having satisfactory electromagnetic transducing characteristics can be formed. Inductance is reduced, resonance frequency is increased, high-frequency driving is enabled and the effect of magnetic and electrical noises due to external disturbance can be controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head of a floating magnetic head used in a magnetic disk drive, which is formed of a laminated film of a magnetic film and an insulating film.

[0002]

2. Description of the Related Art In recent years, miniaturization of magnetic disk drives,
With the increase in capacity, the recording density of data recorded on one magnetic disk has been improved. Generally, the recording density is determined by the size of data recorded on the magnetic disk, and the size of this data is determined by the length and width of the data. In addition, the magnetic head usually has a magnetic core that forms a magnetic circuit with a minute gap called a gap for recording and reproducing data, and a coil wound orthogonal to the magnetic core. It is formed of a magnetic head support called a slider that holds a magnetic core and has an air bearing surface that floats close to a magnetic disk. In order to reduce the width of recorded data, it has been attempted to reduce the track width of the magnetic core in the magnetic head. In addition, in order to reduce the length of the data and further to increase the conversion speed between the electric signal data and the data on the magnetic disk, which is called the data transfer speed, the high frequency of the recording / reproducing frequency. In order to maintain a high resonance frequency and enable high frequency driving, the magnetic head has a low inductance.

In order to cope with such higher recording density,
As a magnetic core for narrowing the track, a laminated type magnetic head in which a laminated film of a magnetic film and an insulating film is arranged on the side surface of a slider (for example, US IEEE TRANSACTI
ONS ON MAGNETICS, VOL. 27, N
O. 6, NOV. 1991 to M. Kitamura,
S. Article published by Mikino, et al. LAM
INATED HARDDISK HEAD FOR
HIGH DENSITY MAGNETICRECO
RDING) is known.

The structure will be described below with reference to FIG. As shown in the figure, in the slider 21 of the laminated magnetic head, a magnetic core 24 is formed on the entire side surface 23 perpendicular to the air bearing surface 22 facing the magnetic disk. The magnetic core 24 is formed of a laminated film of a magnetic film and an insulating film, and includes a core 24 a on the winding portion side and a core 24 b on the slider side extending over the entire side surface 23 of the slider 21 via a gap 25. It is configured. A coil 26 is wound around the core 24a on the winding portion side. Further, the air bearing surface 22 of the slider 21 is provided with a rail 27 for flying the magnetic head and an inclined surface 28 for letting in air for flying.

This laminated magnetic head manufacturing method comprises a step of forming a laminated film of a magnetic film and an insulating film for forming the magnetic core 24 on a non-magnetic substrate for forming the slider 21 by a sputtering method and the like. A step of laminating and joining a plurality of sheets, a step of cutting the joined boards into a bar on the winding side and a bar on the slider body side, and processing a window for the winding by grinding or the like; The bar on the winding side and the bar on the slider body side are bonded to each other through the non-magnetic material that forms the coil so that the positions of the laminated films match each other. And forming a slot for winding at once by
This is due to the step of forming the rail 27 for floating by grinding and lapping, and the step of cutting into individual heads from the bar.

[0006]

In the laminated magnetic head having such a conventional structure, the track width for recording / reproducing data on / from the magnetic disk is determined by the thickness of the laminated film. It has the advantage that it can be made into a track and that it can be manufactured at low cost because a plurality of bars can be manufactured from one substrate and a plurality of sliders can be manufactured from one bar by batch processing. Since the laminated film forming the core 24 is formed on the entire side surface 23 of the slider 21,
The shape of the magnetic core 24 is determined by the shape of the side surface 23 of the magnetic field, which limits the optimization of the magnetic circuit for obtaining high efficiency and good electromagnetic conversion characteristics, and the large area for forming the magnetic circuit reduces the inductance. Is large, the resonance frequency is low, and the problem of increasing the recording and reproducing frequency to limit the increase of recording density, and further, it is easy to detect disturbances such as magnetic and electrical noise.
There is a problem that the reliability of recording and reproducing data is reduced.

The present invention solves the above problems and is capable of high-frequency driving, less affected by disturbances such as magnetic and electrical noises, has good electromagnetic conversion characteristics, low inductance, and low cost, narrow track. It is an object of the present invention to provide a laminated magnetic head.

[0008]

In order to achieve the above object, the present invention forms a magnetic core by joining laminated films with a gap, and the laminated film forming the magnetic core is formed on the side surface of the slider. It is configured to be partially disposed on both sides of the gap.

[0009]

In the above structure, since the laminated film forming the magnetic core is partially disposed on both sides of the gap on the side surface of the slider, the area of the magnetic core is smaller than the total area of the side surface of the slider. As a result, the electromagnetic conversion characteristics are improved and a highly efficient magnetic circuit is formed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

The same parts as those shown in the conventional example are designated by the same reference numerals, and the description thereof will be omitted.

(Embodiment 1) First, a first embodiment will be described with reference to FIGS.

The slider 21 of the laminated magnetic head is made of a non-magnetic material such as CaTiO ₃ , and its side surface 2
The magnetic core 1 is joined and sandwiched between the three. This magnetic core 1
Is formed of a laminated film described later in which a magnetic film and an insulating film are laminated, and includes a core 1a on the winding portion side and a core 1b on the slider side joined via a gap 2 to both sliders 1a, 1b is partially arranged on both sides of the gap 2. Therefore, the area of the magnetic core 1 is equal to the slider 2
1 is much smaller than the total area of the side surface 23.

The laminated film is, for example, as shown in FIG.
The magnetic film 3 made of a sendust film and, for example, SiO ₂
The insulating film 4 made of a film is stacked to have a film thickness for obtaining a desired track width TW. The core 1a on the winding portion side and the core 1b on the slider side formed of this laminated film are joined via a gap 2 to form the magnetic core 1.

By the way, the head sensitivity, which is the main factor that determines the electromagnetic conversion characteristics, is determined by the total combined magnetic resistance obtained by the magnetic resistances of the gap 2 and the magnetic core 1 which form the magnetic circuit. The magnetic resistance is determined by the length, cross-sectional area, and magnetic permeability of each portion of the gap 2 and the magnetic core 1 corresponding to the magnetic path through which the magnetic flux flows. In order to increase the head sensitivity, it is necessary to reduce the total magnetic resistance, and therefore, increase the magnetic permeability of the magnetic core 1 that determines the magnetic resistance of each part, and the magnetic core 1
Is increased, that is, the thickness of the magnetic core 1 is increased and the area of the magnetic core 1 is increased, and the magnetic path length of the magnetic core 1 is shortened and the cross-sectional area of the gap portion 2 is increased. It needs to be small. In particular, the total synthetic reluctance is dominant in the part where the reluctance is large. In FIG. 2C, there is a portion having a large magnetic resistance that minimizes the cross-sectional area of the magnetic path on the core 1a side of the winding portion side. Therefore, even if the slider-side core 24b is formed on the entire side surface of the slider 21 as in the conventional example, a large effect of reducing the total combined magnetic resistance cannot be obtained. However, the cross-sectional area of the magnetic path becomes smaller than the cross-sectional area of the core 1a side of the winding part due to the smaller area of the side surface of the core 1b on the slider side, or the shape, and If the resistance is exceeded, the total combined magnetic resistance is increased and the head sensitivity is deteriorated.

On the other hand, since the inductance is basically in a relationship contradictory to the head sensitivity with respect to the total synthetic magnetic resistance, the magnetic core 1 is increased in cross-sectional area in order to reduce the magnetic resistance of the magnetic core 1. If the area of the side surface of is increased, the inductance increases. Further, the larger the area formed on the side surface of the magnetic core 1, the easier it is to induce disturbance noise. Therefore, in order to suppress the local magnetic resistance, to secure the total combined magnetic resistance to the extent that the required head sensitivity is obtained, and to suppress the required inductance to the extent that the required magnetic inductance is obtained, the magnetic core 1 is set to the core 1b on the slider side. It is effective to form so that the area is 0.5 to 1.5 times the area of the core 1a on the winding portion side. Further, in order to suppress the induced disturbance noise, it is effective to form the magnetic core 1 so that the area thereof is 1/3 or less of the total area of the side surface of the slider 21.

(Second Embodiment) Next, a second embodiment will be described with reference to FIG.

Behind the slider-side core 1b, that is,
The magnetic core 1 on the side surface of the slider 21 on which the laminated film is formed
A bonding film 5 made of a non-magnetic material, for example, a fused glass having a melting point higher than the heating temperature at the time of forming the gap 2 is formed in the other portions. The magnetic core 1 is bonded and sandwiched by the slider 21 by the bonding film 5.

(Third Embodiment) Next, a third embodiment will be described with reference to FIG.

A laminated film 6 that is bonded and sandwiched by a slider 21 together with the magnetic core 1 is formed behind the slider-side core 1b. A non-magnetic separator 7 is provided between the slider-side core 1b and the laminated film 6 so as to separate them from each other and prevent magnetic coupling.

According to the second and third embodiments configured as described above, the inductance can be reduced and the effect of suppressing the influence of disturbance such as magnetic or electrical noise can be obtained.

In the first, second and third embodiments, the slider 21 is made of α-hematite, BaTi.
The magnetic film 3 may be O ₃ or other non-magnetic material, and the magnetic film 3 may be an iron-based or cobalt-based nitride film, permalloy, or any other soft magnetic metal having a high magnetic permeability and a high saturation magnetic flux density. The insulating film 4 may be a film or an amorphous film, and the insulating film 4 may be an alumina film or other non-magnetic insulating film other than the SiO ₂ film.

(Embodiment 4) Next, a laminated magnetic head is manufactured.
An example of the manufacturing method will be described with reference to FIG. Shown in (a)
The width of the slider and cut out to the slider itself
Non-magnetic CaTi with additional thickness for cutting
O₃As shown in (b), the entire surface of the substrate 11 of
SiO forming the edge film 12₂The film is sputtered, for example.
The film is formed by the ring method. On top of that, as shown in (c)
Then, the window 13 having the desired shape of the magnetic core 1 is attached to the slider 21.
Having a plurality of side surfaces 23 according to a predetermined positional relationship,
For example, the substrate 11 is covered with a metal mask 14 and the magnetic film
The sendust film 15 forming the
The film is formed by the sputtering method. Furthermore, the state covered with the mask 14.
Forming the insulating film 4 by SiO₂The membrane 16 is, for example,
It is formed thinner than the magnetic film 3 by the putting method. That
So that the thickness of the laminated film becomes a predetermined track width TW.
SiO₂A laminated film of the film 16 and the sendust film 15 is formed.
It On the substrate 11 on which the laminated film is thus formed,
As shown in (e), the non-magnetic material fused glass 17 is
For example, it is formed by a sputtering method. Next, as shown in (f)
As shown in the above,
Appropriate time for several hours in a furnace with pressure applied by a jig,
Apply proper temperature and fuse. This integrated substrate 11
Of the length of the core 1b on the slider side and the core 1a on the winding side
Depending on the length, as shown in (g)
Cut out into bars 17a and 17b at once
For the bar 17b on the rider side and the bar 17a on the winding side
A groove for the winding window is formed by grinding or the like. It
SiO with a gap of 2 on each surface ₂Membrane and
And fused glass films 18a, 18b, etc.
Position so that the laminated film positions match each other, as shown
Combine and fuse together at an appropriate pressure and temperature to integrate
It Furthermore, as shown in (i), each head lined up in the bar
Slot for winding on the rail side with laminated film
9b is subjected to a collective grinding process, and is shown in (j).
Finish the air bearing surface 22 to a mirror surface by lapping
It Next, the rail 27 facing the air bearing surface 22 of each head is attached.
Collectively grind, and from this bar to each
Batch cutting process to cut out into a single lid, and the circumference of the rail 27
Blending by free abrasive flow that rounds the edge of the side
Perform processing. Finally, as shown in (s),
The coil 26 is wound around the core 1a.

In the above manufacturing method, the magnetic film 3 may be formed by sputtering or vapor deposition.

Further, using the metal mask having the window 13 of the desired shape shown in (c), (d) and (e),
The step of forming a laminated film of the magnetic film 3 and the insulating film 4 in a desired shape of the magnetic core 1 and the fused glass 17 for joining the substrates 11 formed of the laminated film to the entire side surface of the slider 21. In the step of forming, the desired shape of the magnetic core 1 with higher accuracy can be obtained by using a photolithography technique using a mask using a photoresist film of a photosensitive polymer material.

As described above, according to the laminated magnetic head of the embodiment of the present invention, the magnetic film 3 and the insulating film 4 constituting the magnetic circuit are formed.
By appropriately combining the film thickness, the shape of the magnetic core 1, the length of the gap 2, and the number of windings, the area of the laminated film forming the magnetic circuit becomes smaller than that of the conventional laminated magnetic head. A high-efficiency magnetic circuit having good electromagnetic conversion characteristics can be configured, and the inductance can be reduced, the resonance frequency can be increased, and high-frequency driving can be performed. And magnetic noise, for example,
There is an effect that it is possible to suppress the influence of disturbances such as noise due to magnetic flux from an adjacent track on the magnetic disk and electrical noise, for example, noise induced by an inductance component.

Further, according to the manufacturing method described above, the track width for recording and reproducing data on the magnetic disk is determined by the thickness of the laminated film. A plurality of magnetic cores 1 are collectively formed on one substrate 11 by forming a laminated film of the insulating film 4, and a plurality of bars from one substrate 11 and a plurality of head sliders from one bar are collectively formed. Since it is manufactured by processing, there is an effect that an inexpensive laminated magnetic head can be obtained.

[0028]

As is apparent from the above description of the embodiments, according to the present invention, since the laminated film forming the magnetic core is partially disposed on both sides of the side gap of the slider, the magnetic circuit is formed. The area of the magnetic core that composes is smaller than the total area of the side surface of the slider, and it is possible to configure a highly efficient magnetic circuit with good electromagnetic conversion characteristics. Driving can be enabled. Moreover, magnetically,
The influence of disturbance such as electrical noise can be suppressed.

Further, since the track width of the magnetic core is determined by the thickness of the laminated film of the magnetic film and the insulating film formed by the sputtering method or the like, it is possible to make the track narrower controlled with high accuracy.

Further, a large number of magnetic cores can be formed on one substrate, and a plurality of bars can be manufactured from this substrate, and a plurality of head sliders can be manufactured from one bar by batch grinding. Can be reduced and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of a laminated magnetic head according to an embodiment of the present invention.

2A is a plan view seen from the air bearing surface of the same laminated magnetic head, FIG. 2B is a side view thereof, and FIG. 2C is a side sectional view taken along the line AA of FIG.

FIG. 3 is a diagram of a main part of a magnetic core of the same laminated magnetic disk.
The plane sectional view by the BB line of (b)

4A is a plan view seen from the air bearing surface of a laminated magnetic head according to another embodiment. FIG. 4B is a side view of the same, and FIG. 4C is a side sectional view taken along line AA of FIG. 4A.

FIG. 5 is a manufacturing process diagram of the same laminated magnetic head.

6A is a plan view seen from the air bearing surface of a conventional laminated magnetic head. FIG. 6B is a side view thereof. FIG. 6C is a side sectional view taken along the line AA of FIG. 6A.

[Explanation of symbols]

 1 magnetic core 1a winding side core 1b slider side core 2 gap 3 magnetic film 4 insulating film 5 bonding film 6 laminated film behind the magnetic core 7 separator 21 slider 22 air bearing surface 23 side surface

Claims (6)

[Claims] 1. A rotating magnetic disk, comprising: a magnetic core formed of a laminated film of a magnetic film and an insulating film and joined together with a gap to form a magnetic circuit; And a non-magnetic slider having a rail for floating above, wherein a laminated film forming the magnetic core is partially disposed on both sides of the gap on the side surface of the slider. head. 2. A magnetic core formed of a laminated film,
A laminated film that is bonded and sandwiched by a slider behind the magnetic core with the magnetic core, and a laminated film that is separated from the magnetic core and the laminated film behind the magnetic core so as not to be magnetically coupled to each other. 2. The laminated magnetic head according to claim 1, further comprising a non-magnetic separator. 3. The laminated magnetic head according to claim 1, wherein the side surface area of the magnetic core formed by the laminated film is set to 1/3 or less of the side surface area of the slider. 4. The side surface area of the core on the winding portion side of the magnetic core formed by the laminated film is set to 0.5 to 1.5 times the side surface area of the slider side core of the magnetic core. The laminated magnetic head according to claim 1. 5. A magnetic core formed of a laminated film,
2. The laminated magnetic head according to claim 1, wherein a bonding film, which is bonded and sandwiched by a slider together with the magnetic core, is provided behind the magnetic core, and the bonding film is made of laminated fused glass. 6. The laminated magnetic film forming the magnetic core comprises:
2. The laminated magnetic head according to claim 1, which is a soft magnetic metal film or an amorphous film having a high saturation magnetic flux density and a high magnetic permeability, such as Sendust or Permalloy.