JP2906004B2 - Magnetic head - Google Patents

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 in a magnetic disk drive, and more particularly to a composite floating magnetic head.

[0002]

2. Description of the Related Art In FIG. 11, reference numeral 1 denotes a composite floating magnetic head which has been widely used.
The floating magnetic head 1 has a substantially rectangular slider 2 made of barium titanate or calcium titanate. Rails 3 and 4 for generating a levitation force are provided above the slider 2 (the surface facing the magnetic recording medium).

One rail 3 is provided with a slit 5 having a predetermined depth extending in the medium traveling direction of the floating magnetic head 1. The slit 5 has a recording / reproducing gap 6 therein for recording / reproducing. The head core 7 made of a ferromagnetic material is inserted and fixed by means such as sealing with glass. The slider 2 has a coil winding window 8 formed in a notch, which is open on two side surfaces of the slider 2, and a coil 9 is formed in a portion of the head core 7 facing the coil winding window 8. It is wound. In the figure, d is the track width.

In a magnetic head, it is necessary to reduce the thickness of a head core in order to maintain good characteristics with respect to high-frequency signals.
Since it is handled alone until it is inserted into the slit 5, it was difficult to make the head core 7 thin (to a thin shape of 100 microns or less).

In order to control the throat height, it is necessary to measure the apex of the head core 7 sealed with glass obliquely through the glass in the slit 5. In such a case, the measured value may fluctuate due to the refractive index or local distortion of the glass, and the above-mentioned purpose cannot be adequately achieved.

Further, the recent track width d is reduced to 10 μm or less, and the amount of glass filled in the track width adjusting groove of the head core 7 becomes relatively large with respect to the track width d. In addition, the distortion due to the mismatch in the thermal expansion coefficients of the head core (many made of ferrite) increases and the efficiency of the head core 7 deteriorates.

From the above, when the core thickness of the head core 7 is reduced in the conventional shape to cope with a high frequency signal,
Since it is necessary to make the width of the slit 5 narrow, it is difficult to deeply process the slit 5 having a width of 100 μm or less (1 mm or more). Therefore, if only the core thickness is reduced while keeping the width of the slit 5 wide, the gap becomes large, the amount of glass to be filled in becomes large, and the characteristic change due to the mismatch of the thermal expansion coefficient is further increased. is there. Further, there is a problem that it is difficult to fill the glass without generating a gap or a bubble between the slider 2 and the head core 7.

In order to solve the above problem, the present inventor has proposed a floating magnetic head 1a having a structure in which a head core 7 is attached to the outer periphery of a non-magnetic slider 2a as shown in FIG. Improved.

[0009] At present, magnetic recording tends to increase in density. Therefore, in order to cope with this increase in magnetic recording density, the magnetic head must also be reduced in size and weight. However, when reducing the size and weight of the magnetic head, the floating magnetic head 1a shown in FIG. 12 has the following problems.

That is, by reducing the size of the conventional magnetic head, the space (winding window) 10 around which the coil is inevitably narrowed. Therefore, the coil 9 must be extremely thin. For this reason, there has been a problem that the coil 9 is disconnected in the coil winding step, or the insulating coating is peeled off, resulting in a defective product, resulting in a low yield and low reliability.

As shown in FIG. 11 or FIG. 12, in a magnetic head using a winding type conductor coil, there is a limit in reducing the size and weight of the magnetic head due to its structure. Could not.

Therefore, a thin film magnetic head has been developed to solve these problems. This thin film magnetic head 1b
For example, as shown in FIG. 13, a magnetic head member 11 having a small thickness t was provided at one end of a slider 2b. In the magnetic head member 11, a gap 12 is formed as shown in FIG. 12, and a magnetic circuit 13 is formed within a small thickness t.

[0013]

By the way, in the thin-film magnetic head 1b having the above-described magnetic head member 11, the problem of the above-described conventional magnetic head using a winding type conductor coil has been solved. Then, the following problem is caused. That is, this thin-film magnetic head
1b, the magnetic circuit 13 is formed in the magnetic head member 11 having a small thickness t. Therefore, when the cross-sectional area of the magnetic circuit 13 is reduced and the magnetic resistance is increased, the induced electromotive force is reduced and recording is performed. There is a problem that reproduction characteristics are deteriorated.

The present invention has been made in view of the above circumstances, and has as its object to provide a magnetic head having good recording and reproducing characteristics.

[0015]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a recording / reproducing method for recording / reproducing on the outer peripheral portion of a slider made of a non-magnetic material having a rail for generating a floating force on a surface facing a magnetic storage medium. Head core with gap for
And a pair of magnetic materials on both sides of the first non-magnetic material.
And a magnetic body of one of the pair of magnetic bodies.
A substrate integrally provided by providing a second non-magnetic material on the outside ;
A magnetic core magnetically connected so to the pair of magnetic material across the first non-magnetic member, said magnetic core as a magnetic core
Disposed on the substrate corresponding to a pair of magnetic materials, respectively;
A pair of balanced-wound thin-film coils;
Bones arranged on a magnetic body and connected to the thin film coil
It has a thin-film coil assembly comprising a loading pad, before
The surface of the substrate opposite to the magnetic core arrangement surface is
The thin film coil assembly is joined to a head core side on a side opposite to a slider joining surface of the head core.

[0016]

With this configuration, since the thin film coil assembly is joined to the head core on the side opposite to the slider joining surface, a window for winding is not required in the head core, and the magnetic path length can be shortened.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic head according to an embodiment of the present invention will be described below with reference to FIGS. First, a first embodiment of the present invention will be described with reference to FIGS. Here, FIG.
The same members and portions as the members illustrated in FIG. 14 are denoted by the same reference numerals, and the description thereof will not be repeated. In the second embodiment described below, the same members and portions are treated similarly.

Referring to FIG. 1 to FIG.
Has a substantially rectangular slider 21. Rails 3 and 4 for generating a levitation force are provided above the slider 21 (the surface facing the magnetic recording medium). A head core 22 having a recording / reproducing gap 6 is bonded to a side portion (outer peripheral portion) of a slider 21 corresponding to one of the rails 3 by glass bonding, and a thin film coil assembly is provided on a side of the head core 22 opposite to a slider bonding surface 23. Three-dimensional
24 are joined. In this case, the head core 22 and the
1, 2, 3, 7, and 7 in forming a magnetic circuit in FIG.
As shown in FIG. 8, the pair of magnetic bodies 25 and 26 are connected to each other.
On the side of the core 25 (ie, the thin-film coil assembly 2).
4 on a substrate 43 (described later).
A surface portion (the lower portion in FIG. 8) opposite to the surface on which the
Side) with the head core side], and the thin film coil assembly 24 is
Slider joining in head core 22 as described above
It is joined to the side opposite to the surface 23. Also, the head core 22
After the head core 22 is joined to the slider 21, the head core 22 is thinned. The head core 22 is joined to the slider 21 by resin bonding or Au-Sn.
Or the like by eutectic metal bond.

As shown in FIGS. 3 and 4, the head core 22 has a pair of magnetic bodies 25 and 26 arranged opposite to each other, and forms a recording / reproducing gap 6 above the upper side (the upper side in FIG. 3). A gap 27 having a predetermined width is formed on the lower side, and the gap 27 is filled with a non-magnetic material 28 such as glass.
By filling 28, the magnetic circuit formed by the recording / reproducing gap 6 and the pair of magnetic bodies 25 and 26 is magnetically cut. Glass 30 is filled in recesses 29 formed on both upper sides (upper side in FIG. 3) of the pair of magnetic bodies 25 and 26, and the recording and reproducing gap 6 in the pair of magnetic bodies 25 and 26 is filled. The lower gap 31 is filled with an adhesive 32 such as glass to bond the pair of magnetic bodies 25 and 26 together. Instead of filling the space 27 with the nonmagnetic material 28, the space 27 may be left in a hollow state.

The head core 22 may be replaced with a head core 22a shown in FIGS. The head core 22a has a pair of magnetic bodies 34 and 35 having an inclined surface 33 on one side (upper side in FIG. 5) of the head core 22 and a structure in which the glass 30 used for the head core 22 is omitted. It has become.

The structure of the thin-film coil assembly 24 will be described with reference to FIGS. Magnetic material such as ferrite (pair
The magnetic body) 40 and 41 (in this embodiment, the magnetic body 41 is one
The other magnetic material. ) Are adhered to each other with a non-magnetic material 42 such as glass to form a substrate 43. Book
In the embodiment, among the non-magnetic members 42, FIG. 1, FIG. 7 and FIG.
As shown, a pair of magnetic bodies 40, 41
The non-magnetic material 42 constitutes a first non-magnetic material, and the magnetic material (one
The non-magnetic body 42 provided outside the (magnetic body) 41
2 non-magnetic materials. The substrate 43 can also be obtained by forming a concave groove in the magnetic material by machining, filling the concave groove with molten glass, and solidifying the glass, and then grinding both surfaces of the magnetic material into mirror surfaces.

A first insulating film 44 is formed on the mirror surface of the substrate 43, and after the first insulating film 44 is formed, a first layer thin-film coil 45 is formed on the first insulating film 44 by a known technique. A second insulating film 46 is formed on the first layer thin film coil 45,
After the formation of the insulating film 46, a second-layer thin-film coil 47 is formed on the second insulating film 46 by a known technique. In this embodiment,
The first-layer thin-film coil 45 and the second-layer thin-film coil 47 are paired.
Of the thin film coil. A third insulating film 48 is formed on the second-layer thin-film coil 47, and a thin-film magnetic core (magnetic core) 49 is formed on the third insulating film 48 after the formation of the third insulating film 48.

The first, second, and third insulating films 44, 46,
Reference numeral 48 denotes an organic resin-based insulating film such as a photoresist or a polyimide, or an inorganic insulating film such as SiO ₂ or Al ₂ O ₃ . The first and second layer thin-film coils
45 and 47 are manufactured by a method of performing copper plating by a frame plating method using a resist frame or an etching performed by using a photoresist mask.
The thin film magnetic core 49 is formed by plating a magnetic film such as permalloy by a frame plating method using a resist frame, or by etching a magnetic thin film such as permalloy prepared by vapor deposition or sputtering using a resist mask. And so on. The first and second layer thin film coils 45 and 47 are spirally wound around magnetic cores 50 and 51. In the figure, reference numeral 52 denotes a bonding pad.

In the magnetic head thus configured, the thin film coil assembly 24 is connected to the slider joining surface 23 of the head core 22.
The head core 22 does not require a window for winding, and the magnetic path length can be shortened. For this reason, the magnetic resistance of the head core 22 is reduced, and the induced electromotive force is correspondingly increased, so that the recording and reproducing characteristics can be improved. In addition, the use of the thin-film coil assembly 24 can reduce the size of the entire device.

In addition, since the head core 22 is arranged on the outer peripheral portion of the slider 21, the slider 21 does not need to be slit, and the productivity is improved by that amount. After the head core 22 is joined to the slider 21, the head core 22 is processed to be thin. Therefore, the head core 22 alone can be made somewhat thick (100 microns or more), and can be processed to be thin (100 microns or less) after bonding. For this reason, the eddy current is reduced, and the characteristics at high frequency signals are improved.

Since the capacity of the track adjusting groove is reduced and the amount of glass filled in the track adjusting groove is reduced, distortion due to mismatch of the thermal expansion coefficients of the glass, the slider 21 and the head cores 22 and 22a is reduced accordingly. The thin-film coil assembly 24 can be easily manufactured by using a widely-used semiconductor integrated circuit manufacturing technique, whereby mass production of the thin-film coil assembly 24 and thus the entire device can be achieved. The first and second layer thin-film coils 45 and 47
The magnetic cores 50 and 51 are wound in a spiral shape, thereby enabling a balance winding. Therefore, by using the balance winding, it is possible to cancel external noise.

FIGS. 9 and 10 show a magnetic head 22a according to a second embodiment of the present invention. The magnetic head 22a has a first
As compared with the magnetic head 22 of the embodiment, the slider 21
In place of the head core 22, a slider 21 a having a notch 60 having a depth corresponding to the thickness of the head core 22 is provided. The head core 22 is positioned and joined to the notch 60 of the slider 21 a, whereby the side surface ( Head core 2
2 and the side surface of the slider 21a are flush with each other, and the thin film coil assembly 2 is replaced with the thin film coil assembly 24.
Thin-film coil assembly 24a having a length m longer than
Is different. Although the thin-film coil assembly 24a having a length m longer than the thin-film coil assembly 24 is used, the side surface of the head core 22 and the side surface of the slider 21a are formed as described above. This is achieved by being on the same plane.

The second embodiment has the same advantages as the first embodiment, and also has a thin-film coil assembly 24a.
The length m of the thin film coil assembly 24a has an advantage that the length of the length m is longer and the degree of freedom in designing is increased accordingly.

[0029]

Since the present invention is a magnetic head constructed as described above, the thin-film coil assembly is joined to the head core on the side opposite to the slider joining surface, so that the winding window is formed on the head core. Is unnecessary, and the magnetic path length can be shortened. Therefore, the magnetic resistance of the head core is reduced, and the induced electromotive force is correspondingly increased, so that the recording and reproducing characteristics can be improved.

[Brief description of the drawings]

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

FIG. 2 is an enlarged perspective view showing a part of the magnetic head.

FIG. 3 is a perspective view showing a head core of the magnetic head.

FIG. 4 is a plan view of a circle of FIG. 3;

FIG. 5 is a perspective view showing another example of the head core used in the magnetic head.

FIG. 6 is a plan view of a circle of FIG. 5;

FIG. 7 is a partially cutaway perspective view showing a thin-film coil assembly of the magnetic head.

FIG. 8 is a cross-sectional view showing the thin-film coil assembly.

FIG. 9 is an exploded perspective view showing a magnetic head according to a second embodiment of the present invention.

FIG. 10 is an enlarged perspective view showing a part of the magnetic head.

FIG. 11 is a perspective view showing an example of a conventional magnetic head.

FIG. 12 is a perspective view showing an example of a conventional magnetic head in which a head core is provided on an outer peripheral portion of a slider.

FIG. 13 is a plan view showing an example of a conventional magnetic head having a magnetic head member.

FIG. 14 is a front view showing the magnetic head.

[Explanation of symbols]

 3 rail 4 rail 6 gap for recording / reproducing 21 slider 22 head core 23 slider joint surface 40 magnetic material 41 magnetic material 42 non-magnetic material 43 substrate 49 thin film magnetic core 50 magnetic core 51 magnetic core

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 5/17 G11B 5/60

Claims (1)

(57) [Claims] 1. A head core having a recording / reproducing gap is joined to an outer peripheral portion of a slider made of a non-magnetic material having a rail for generating a levitation force on a surface facing a magnetic storage medium.
And a pair of magnetic materials on both sides of the first non-magnetic material.
And a magnetic body of one of the pair of magnetic bodies.
A substrate integrally provided by providing a second non-magnetic material on the outside ;
A magnetic core magnetically connected so to the pair of magnetic material across the first non-magnetic member, said magnetic core as a magnetic core
Disposed on the substrate corresponding to a pair of magnetic materials, respectively;
A pair of balanced-wound thin-film coils;
Bones arranged on a magnetic body and connected to the thin film coil
It has a thin-film coil assembly comprising a loading pad, before
The surface of the substrate opposite to the magnetic core arrangement surface is
A magnetic head, wherein the thin-film coil assembly is joined to a head core side on a side opposite to a slider joining surface of the head core.