JP2000067412A - Magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance head characteristics by successively forming a nonmagnetic oxidized layer and a nonmagnetic metallic layer from the butted surfaces of magnetic core halves to form a nonmagneitc film. SOLUTION: The magnetic head has nonmagnetic films 8 formed on the joined surfaces 2a, 3a of a pair of magnetic core halves 2, 3 and the nonmagnetic films 8 have functions as the front and back gaps of the magnetic core. A pair of the magnetic core halves 2, 3 are joined into one body by applying metallic dispersion to the nonmagnetic films 8 respectively formed on the joined surface of a pair of the magnetic core halves 2, 3. In the magnetic head, the diffusion of the nonmagnetic metallic layer 8a formed of a metal having a high diffusion coeff. into a metallic magnetic thin film 5 forming the magnetic core is prevented by the nonmagnetic oxidized layer 8b. The magnetic head clearly forms a magnetic interface in the front gap of the magnetic core and the gap length is made to a desired value by controlling the thickness of the metallic nonmagnetic films 8a formed on the joined surfaces 2a, 3a of a pair of the magnetic core halves 2, 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head having a magnetic path formed by a metal magnetic thin film, and more particularly, to a magnetic head in which a pair of magnetic core halves are joined and integrated by metal diffusion bonding.

[0002]

2. Description of the Related Art A magnetic head is mounted on a magnetic recording / reproducing device such as a video tape recorder (VTR), and records and / or reproduces information signals on a magnetic recording medium (hereinafter referred to as recording / reproducing). Is what you do.

In a magnetic head, a metal magnetic thin film is formed on each magnetic gap forming surface of a pair of magnetic core halves made of single crystal ferrite or the like, and the pair of magnetic core halves are joined to the magnetic gap forming surfaces. A so-called metal-in-gap (MIG) type magnetic head, which is integrated by bonding together, and a so-called laminated type magnetic head in which a metal magnetic thin film is sandwiched between nonmagnetic ceramic substrates have been proposed and put into practical use.

[0004] In order to cope with higher density and digitization of a recording signal in the field of magnetic recording, a magnetic head that can exhibit good electromagnetic conversion characteristics in a higher frequency band is desired. Further, it is desired that a magnetic head for a VTR be miniaturized in order to cope with miniaturization and high performance of the apparatus by mounting a plurality of magnetic heads on a small drum.

The above-described MIG type magnetic head has a large impedance and is not suitable for use in a high frequency band. Also,
The stacked magnetic head requires a reduction in the thickness of the metal magnetic thin film forming the magnetic path with a decrease in the track width due to an increase in the density of the recording signal. There is a limit to miniaturization.

Therefore, as a magnetic head capable of exhibiting good electromagnetic conversion characteristics in a high frequency band, for example, as described in JP-A-6-259717, "Magnetic head and its manufacturing method". A so-called bulk thin-film magnetic head has been proposed in which the impedance is reduced by shortening the magnetic path of a magnetic core manufactured by a thin-film forming process.

In this bulk thin film type magnetic head, a pair of magnetic core halves each having a metal magnetic thin film formed as a magnetic core on a nonmagnetic substrate are joined and integrated with each other via the nonmagnetic film. A magnetic gap is formed between these metal magnetic thin films. In this bulk thin-film magnetic head, a coil-forming recess is formed on a joining surface of at least one of the pair of magnetic core halves, and a thin-film coil is formed in the coil-forming recess. .

[0008]

By the way, a pair of magnetic core halves are formed by forming the above-mentioned non-magnetic film with non-magnetic metal atoms and performing metal diffusion bonding with the non-magnetic metal atoms to form a joint. Is done. In other words, this non-magnetic film has a function as a magnetic gap in the magnetic core, and also has a function as an adhesive when the pair of magnetic core halves is subjected to metal diffusion bonding.

Therefore, as the nonmagnetic metal atoms forming the nonmagnetic film, a metal having a large diffusion coefficient and hardly forming an oxide layer on the surface is selected so as to be suitable for metal diffusion bonding at a low temperature. Specifically, a noble metal such as Au or Pt is selected.

In the magnetic head configured as described above, it is difficult to control the gap length of the magnetic gap to a desired value. In particular, a metal film used in metal diffusion bonding is used as a gap material. When used, it was difficult to form a magnetic gap having a predetermined gap length. Therefore, the conventional magnetic head has a problem that the head characteristics are deteriorated.

Accordingly, an object of the present invention is to provide a magnetic head having improved head characteristics.

[0012]

Means for Solving the Problems In order to achieve the above object, the present inventors have conducted intensive studies. As a result, the diffusion of non-magnetic metal atoms of the non-magnetic film into the metal magnetic thin film caused these interfaces to become non-conductive. Clarified that it becomes clear. Further, the present inventors have formed a non-magnetic film by a non-magnetic metal layer and a non-magnetic oxide layer, and by disposing the non-magnetic oxide layer between the non-magnetic metal thin film, this non-magnetic metal layer It has been found that it is possible to prevent the metal magnetic thin film from diffusing, and to improve the recording / reproducing characteristics.

That is, a magnetic head according to the present invention has a metal magnetic thin film formed obliquely on a substrate, a concave portion in which a thin film coil is formed, and a butted surface made flat by a nonmagnetic material. A magnetic head comprising a pair of magnetic core halves, wherein a magnetic gap is formed by abutting the end faces of the metal magnetic thin film so as to face each other via a nonmagnetic film. A non-magnetic oxide layer and a non-magnetic metal layer are formed in this order from the butted surface side of the half.

In the magnetic head according to the present invention configured as described above, the diffusion of the nonmagnetic metal layer into the metal magnetic thin film formed on the magnetic core half by the nonmagnetic oxide layer of the nonmagnetic film. Is prevented. Therefore, in such a magnetic head, the magnetic interface in the magnetic gap becomes clear.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. Hereinafter, the magnetic head 1 as shown in FIGS. 1 and 2 will be described.

The magnetic head 1 according to the present invention comprises a pair of magnetic core halves 2 and 3 joined by metal diffusion bonding. The pair of magnetic core halves 2 and 3 are made of MnO—N
a non-magnetic substrate 4 made of an iO-based non-magnetic material, and a metal magnetic thin film 5 formed on an inclined surface 4a of the non-magnetic substrate 4
And a low melting point glass 6 formed on the non-magnetic substrate 4 so as to cover the metal magnetic thin film 5. Further, at least one of the pair of magnetic core halves 2 and 3 is formed with a thin-film coil 7 for excitation and / or detection of an induced electromotive force.

In the magnetic head 1, in a state where the pair of magnetic core halves 2 and 3 are joined via the non-magnetic film 8, the metal magnetic thin film 5 is connected to the thin film coil shown in FIG. The magnetic core 9 is formed as shown in FIG. In the magnetic head 1, when the magnetic recording medium slides in a direction indicated by an arrow A in FIG. 2, the magnetic core 9 reproduces the signal magnetic field recorded on the magnetic recording medium, or the magnetic core 9 generates the signal magnetic field. It operates by recording on a recording medium.

In order to adjust the contact state of the magnetic head 1 with the magnetic recording medium, the sliding surface 10 of the magnetic recording medium is moved in the sliding direction of the magnetic recording medium indicated by an arrow A in FIG. It is formed in an arc shape in parallel. The magnetic head 1 is used to adjust the contact area with the magnetic recording medium.
A contact width regulating groove 11 is formed. The contact width regulating grooves 11 are formed on both side surfaces of the magnetic head 1 in parallel with the sliding direction A of the magnetic recording medium.

In this magnetic head 1, the metal magnetic thin film 5 is formed of a material exhibiting soft magnetism such as an Fe-Ta-N alloy. The metal magnetic thin film 5 is formed on an inclined surface 4 a formed obliquely at a predetermined angle on the non-magnetic substrate 4. Therefore, when the pair of magnetic core halves 2 and 3 on which the metal magnetic thin film 5 is formed are joined via the non-magnetic film 8, the magnetic core 9 slides on the magnetic recording medium as shown in FIG. It is arranged obliquely to the moving direction A.

The metal magnetic thin film 5 is configured so that its cross section has a substantially U-shape. That is, the metal magnetic thin film 5 is formed on the joining surface 2 of the magnetic core halves 2 and 3.
A substantially central portion of the end surfaces on the sides a and 3a is formed as a concave portion 5a.

For this reason, the metal magnetic thin film 5 is divided by the joining surfaces 2 a and 3 a of the magnetic core halves 2 and 3 in the front-rear direction and is exposed from the low-melting glass 6. And has the following. The front butting surface 12 of one magnetic core half 2 and the front butting surface 12 of the other magnetic core half 3 are butted with the nonmagnetic film 8 interposed therebetween to form a front gap 14. Also, the rear butting surface 13 of one magnetic core half 2 and the rear butting surface 13 of the other magnetic core half 3 are butted via the nonmagnetic film 8 to form a back gap 15.

The metal magnetic thin film 5 has a bonding surface 2a,
3a, the thin film coil 7 having the rear butting surface 13 substantially at the center.
Has a coil forming recess 16 formed therein. A coil connection terminal 17 is formed in the coil forming recess 16 near the rear butting surface 13. The thin-film coil 7 is formed in the coil-forming recess 16, and the end on the center side is connected to the coil connection terminal 17.

The coil connection terminals 17 are formed with their heights adjusted so as to form the same surfaces as the joining surfaces 2a, 3a of the pair of magnetic core halves 2, 3. Then, in the magnetic head 1, when the pair of magnetic cores 2 and 3 are joined, the pair of coil connecting terminals 17 are also joined. Thus, in the magnetic head 1, when the pair of magnetic core halves 2 and 3 are joined, the pair of thin-film coils 7 are electrically connected.

The outer peripheral end of the thin-film coil 7 is led out to the side opposite to the sliding surface 10 of the recording medium. External connection terminals 18 are formed on the pair of magnetic core halves 2 and 3 on the side opposite to the sliding surface 10 of the recording medium. The outer peripheral end of the thin-film coil 7 is connected to the external connection terminal 18.

These external connection terminals 18 are exposed to the side surface of the magnetic head 1 so that they can be connected to the outside by the thin film coil 7.
And can be electrically connected. The pair of external connection terminals 18 are formed at positions where the heights of the pair of magnetic core halves 2 and 3 are different so that a short circuit does not occur when the pair of magnetic core halves 2 and 3 are joined. Have been.

As shown in FIG. 3, the magnetic head 1 has a non-magnetic film 8 formed on the joint surfaces 2a and 3a of the pair of magnetic core halves 2 and 3, respectively. The non-magnetic film 8 includes a non-magnetic metal layer 8a and a non-magnetic oxide layer 8b.

The nonmagnetic film 8 is formed between the front butting surfaces 12 and the rear butting surfaces 13 of the pair of magnetic core halves 2 and 3 in the magnetic head 1 as described above. Thereby, the magnetic core 9 functions as the front gap 14 and the back gap 15. The non-magnetic film 8 is formed on the bonding surfaces 2a and 3a of the pair of magnetic core halves 2 and 3, respectively, and is subjected to metal diffusion bonding, as described later, to thereby form the pair of magnetic core halves. It has the function of joining and integrating the two and three.

The non-magnetic metal layer 8a is made of a metal having a large diffusion coefficient and a surface on which an oxide layer is hardly formed so as to be suitable for metal diffusion bonding at a low temperature. A metal such as Au is formed with a thickness of about 100 nm. The non-magnetic metal layer 8a is formed on the non-magnetic substrate 4
Are formed on the outermost sides of the non-magnetic film 8, respectively, and are joined to each other by metal diffusion bonding to be joined and integrated.

The non-magnetic oxide layer 8b is formed to prevent the non-magnetic metal layer 8a formed of a metal having a large diffusion coefficient from diffusing into the metal magnetic thin film 5 constituting the magnetic core 9. It is formed on the innermost side of the nonmagnetic film 8 with respect to the nonmagnetic substrate 4. In other words, the nonmagnetic oxide layer 8b is formed on the bonding surfaces 2a and 3a, that is, on the metal magnetic thin film 5. Non-magnetic oxide layer 8b
Specifically, for example, 10n is formed of a material such as SiO _2.
It is formed with a thickness of about m.

In the magnetic head 1, as described above, the non-magnetic oxide layer 8 b and the non-magnetic metal layer 8 a are formed from the non-magnetic substrate 4 side at the joining surfaces 2 a and 3 a of the pair of magnetic core halves 2 and 3. The non-magnetic film 8 is formed in this order.

Therefore, in the magnetic head 1, the fact that the nonmagnetic metal layer 8 a formed of a metal having a large diffusion coefficient diffuses into the metal magnetic thin film 5 forming the magnetic core 9 is determined by the fact that the nonmagnetic oxide layer 8 b It is prevented by. Since the nonmagnetic oxide layer 8b is made of SiO ₂ or the like, it does not diffuse into the metal magnetic thin film 5.

Therefore, the magnetic head 1 can clearly form a magnetic interface in the front gap 14 of the magnetic core 9. For this reason, in the magnetic head 1, the gap length is the distance between the respective end faces of the metal magnetic thin film 5 formed on the pair of magnetic core halves 2 and 3. Therefore, in the magnetic head 1, by controlling the thickness of the non-magnetic film 8 formed on the joint surfaces 2a and 3a of the pair of magnetic core halves 2 and 3, the gap length is accurately set to a desired value. be able to. As a result, the magnetic head 1 has improved recording and reproduction characteristics.

In the magnetic head 1, the non-magnetic substrate 4 is made of a MnO-NiO-based non-magnetic material, but the present invention is not limited to such a configuration. The nonmagnetic substrate 4 may be made of calcium titanate, barium titanate, zirconium oxide (zirconia), alumina, alumina titanium carbide, SiO ₂ , Zn ferrite, crystallized glass, high hardness glass, or the like.

In the magnetic head 1, the non-magnetic substrate 4 has the inclined surface 4a formed at a predetermined angle, but the inclined surface 4a is formed in, for example, a circular or polygonal shape. You may. However, the slope 4a is 45
It is desirable to form at an angle of about degrees. Thereby, the track width accuracy of the magnetic head 1 is improved.

Further, in the magnetic head 1, the metal magnetic thin film 5 is formed of a material exhibiting soft magnetism such as an Fe-Ta-N alloy, but the present invention is not limited to this configuration. The metal magnetic thin film 5 is made of, for example, Sendust (Fe-Al-Si alloy), Fe-Al alloy, Fe-S
i-Co alloy, Fe-Ga-Si alloy, Fe-Ga-S
i-Ru alloy, Fe-Al-Ge alloy, Fe-Ga-G
e alloy, Fe-Si-Ge alloy, Fe-Co-Si-A
Any material may be used as long as it is made of a crystalline alloy such as a 1 alloy or an Fe-Ni alloy. Alternatively, the metal magnetic thin film 5 is made of Fe, C
alloy consisting of one or more elements of o and Ni and one or more elements of P, C, B and Si, or Al, Ge, Be, Sn, In, Mo, W, Ti, M
metal-metalloid amorphous alloys typified by alloys containing n, Cr, Zr, Hf, Nb, etc .;
It may be made of an amorphous alloy such as a metal-metal amorphous alloy containing a transition metal such as Hf or Zr and a rare earth element as main components. Further, the metal magnetic thin film 5
May be a nitrided soft magnetic alloy or a carbonized soft magnetic alloy.

The metal magnetic thin film 5 may be constituted by a metal magnetic thin film having a single layer. However, it is preferable that a nonmagnetic thin film layer and a magnetic thin film layer are alternately laminated. Thus, the magnetic head 1 can have high sensitivity in a higher frequency range.

Further, in the above-described embodiment, the non-magnetic metal layer 8a of the non-magnetic film 8 is formed of Au. It may be formed by at least one kind. In the above-described embodiment, the non-magnetic oxide layer 8b of the non-magnetic film 8 is formed of SiO _2. However, for example, the non-magnetic oxide layer 8b is formed of at least one selected from materials such as Al ₂ O ₃ and TiO _2. Is also good.

In the above-described embodiment,
The non-magnetic film 8 is formed by the non-magnetic metal layer 8a and the non-magnetic oxide layer 8b, but by providing a non-magnetic underlayer between the non-magnetic metal layer 8a and the non-magnetic oxide layer 8b,
May be formed. In the magnetic head 1, by forming the nonmagnetic underlayer with, for example, Cr, Ti, Cu, or the like, the bonding strength between the nonmagnetic metal layer 8a and the nonmagnetic oxide layer 8b can be increased. Therefore, in the magnetic head 1, the pair of magnetic core halves 2 and 3 can be securely joined and integrated.

The non-magnetic underlayer is a non-magnetic oxide layer 8b.
Is formed on the metal magnetic thin film 5 through the metal film, and therefore, does not diffuse into the metal magnetic thin film 5. Therefore,
The magnetic head 1 can clearly form a magnetic interface in the front gap 14 of the magnetic core 9 even when the nonmagnetic film 8 has a nonmagnetic underlayer. Therefore, even in this case, in the magnetic head 1,
Metal magnetic thin film 5 formed on a pair of magnetic core halves 2 and 3
Is the gap length. Therefore, in the magnetic head 1, by controlling the thickness of the non-magnetic film 8 formed on the joint surfaces 2a and 3a of the pair of magnetic core halves 2 and 3, the gap length is accurately set to a desired value. be able to. This allows the magnetic head 1
Means that the recording and reproduction characteristics are improved.

The magnetic head 1 configured as described above is
When reproducing a magnetic signal recorded on the magnetic recording medium, a signal magnetic field from the magnetic recording medium is applied around the front gap 14. When the direction of the applied signal magnetic field changes, the direction of the magnetic flux flowing through the magnetic core 9 changes. As a result, in the magnetic head 1, electromagnetic induction occurs, and a predetermined current flows through the thin-film coil 7.

When a magnetic signal is recorded on a magnetic recording medium using the magnetic head 1, a predetermined current is supplied to the thin-film coil 7. And this magnetic head 1
Then, the magnetic core 9 is generated by the magnetic field generated from the thin film coil 7.
A predetermined magnetic flux flows through the. Thereby, this magnetic head 1
Then, a leakage magnetic field is generated across the front gap 14. The magnetic head 1 records a magnetic signal by applying the leakage magnetic field to a magnetic recording medium.

Next, a method of manufacturing the above-described magnetic head 1 will be described.

The magnetic head 1 is formed on the same substrate with the magnetic core halves 2 and 3 connected in a plurality of rows. The substrate is provided with a plurality of magnetic core halves 2, 3
Are separated for each row in which is formed, to form a magnetic core half block. The magnetic core half blocks are joined and integrated by metal diffusion bonding to form a magnetic head block. The magnetic head 1 is completed by separating the magnetic head block into individual magnetic heads 1.

First, to manufacture the magnetic head 1,
As shown in FIG. 4, a substantially flat substrate 21 is prepared. This substrate 21 is to be the non-magnetic substrate 4 of the magnetic head 1, and is made of a non-magnetic material such as MnO-NiO. The substrate 21 has a thickness of about 2 mm, for example.
The length and width are set to about 30 mm.

Next, as shown in FIG.
For example, a plurality of magnetic core forming grooves 24 are formed with a grindstone or the like so as to have an angle of about 45 degrees with respect to one main surface 21a.
Are formed in parallel. Then, a plurality of inclined surfaces 21b are formed in the substrate 21 by the magnetic core forming grooves 24 formed in the first groove processing. Inclined surface 21b
Are the inclined surfaces 4a in the magnetic head 1.

The inclined surface 21b formed here is
It may be circular or polygonal. Also, the inclined surface 21b
Is preferably about 25 to 60 degrees with respect to the plane of the substrate 21, but is more preferably about 35 to 50 degrees in consideration of prevention of pseudo gap and track width accuracy.
The magnetic core forming groove 24 formed by the first groove processing had a depth of 130 μm and a width of 150 μm.

Next, as shown in FIG. 6, a metal magnetic thin film 27 is formed on the entire surface of the substrate 21 on which the inclined surface 21b is formed. In this film forming step, the metal magnetic thin film 27
Is formed so that three metallic magnetic materials are laminated via a nonmagnetic layer. This metal magnetic thin film 27 is formed, for example, by a PVD method such as a magnetron sputtering method or the like.
The film is formed by a VD method or the like.

Further, the metal magnetic thin film 27 is not limited to the one having a plurality of metal magnetic layers, and may be configured to have a single metal magnetic layer. In order to obtain, it is desirable that the metal magnetic layer has a laminated structure in which the metal magnetic layer is divided into a plurality. Thereby, the metal magnetic thin film 27 can reduce the eddy current loss and obtain high sensitivity in a higher frequency band.

In this embodiment, the metal magnetic thin film 27
Is, for example, 4 μm of Fe—Ta—N alloy and 0.1 μm of alumina.
15 μm are alternately laminated, and have a configuration having three Fe—Ta—N alloy layers. The metal magnetic thin film 2
When the film 7 is formed into a plurality of layers, materials such as alumina, SiO _2, and SiO are used alone or as a mixture for the nonmagnetic layer. The thickness of the non-magnetic layer is set to such an extent that insulation between adjacent metal magnetic layers can be obtained.

Next, as shown in FIG.
A second groove is formed on the surface on which the groove 7 is formed in a direction substantially orthogonal to the magnetic core forming groove 24. In the second groove processing, a separation groove 28 formed for separating the magnetic core 9 into a predetermined size, and a winding for forming a magnetic gap in each magnetic core 9 separated by the separation groove 28. Wire groove 29
And are formed.

At this time, portions other than the metal magnetic thin film 27 formed on the inclined surface 21b, that is, the metal magnetic thin film 27 formed on the bottom of the magnetic core forming groove 24 are removed by grinding.

Here, the separation groove 28 is a groove for forming each magnetic core 9 by magnetically separating the magnetic core 9 in the front-back direction on the substrate 21 and forming a closed magnetic path in each magnetic core 9. is there. Although two separation grooves 28 are formed in the example of FIG. 7, the separation grooves 28 need to be provided by the number of rows of the magnetic core halves 2 and 3 to be formed. In addition, the separation groove 28 must be formed to have a depth that can completely cut the metal magnetic thin film 27 in order to magnetically separate the magnetic cores 9 arranged in the front-rear direction. is there. Specifically, the separation groove 28 has a depth of 150 μm from the bottom of the magnetic core formation groove 24, that is, 280 μm from the main surface 21 a of the substrate 21.
And the depth.

On the other hand, the winding groove 29 forms a concave portion 5 a formed in the metal magnetic thin film 27 in the magnetic head 1 described above. Therefore, the winding groove 29 is formed on the magnetic core 9 having the front butting surface 12 and the rear butting surface 13.
In order to form the recess 16 for forming the coil, it is necessary to form the metal magnetic thin film 27 at a depth that does not cut it. Therefore, the cross section of the metal magnetic thin film 27 is exposed on the surface of the winding groove 29.

The shape of the winding groove 29 is determined according to the lengths of the front butting surface 12 and the rear butting surface 13. Here, the width is set to about 140 μm, and And the length of the rear abutting surface 13 was 85 μm. The winding groove 29 may have such a depth that the metal magnetic thin film 27 is not cut. However, if the winding groove 29 is too deep, the magnetic path length becomes longer and the efficiency of magnetic flux transmission may be reduced. The depth of the winding groove 29 depends on the thickness of the thin-film coil 7 formed in a step described later, but is 20 μm here.

Further, the shape of the winding groove 29 is not limited, but here, the front abutting surface 12
The side surface was a 45-degree inclined surface 29a. This allows
The magnetic core 9 has a structure in which the magnetic flux is concentrated on the sliding surface 10 so that the sensitivity is improved.

Next, as shown in FIG. 8, the low melting point glass melted on one main surface 21a of the substrate 21 on which the magnetic core forming groove 24, the separation groove 28 and the winding groove 29 are formed as described above. 30 is filled. Thereafter, the low-melting glass 30 is cooled and solidified, and the surface of the solidified low-melting glass 30 is subjected to a flattening process.

Next, as shown in FIG. 9, a terminal groove 31 is formed by subjecting the solidified low melting point glass 30 to grinding using a grindstone or the like. The terminal groove 31 was formed so as to be located immediately above the above-described separation groove 28. The shape, width, and depth of the terminal groove 31 are not limited, but here, the width and depth are set to 100 μm. Then, a good conductor such as Cu is filled in the terminal groove 31 by plating or the like. After that, the flattening process is performed again.
The good conductor such as Cu filled in the terminal groove 31 serves as the external connection terminal 18 in the magnetic head 1 described above.

Next, as shown in FIG. 10, the low-melting glass 30 is subjected to an etching process to form a coil-forming recess 16 and a thin-film coil 7 is formed in the coil-forming recess 16. I do.

The concave portion 16 for forming a coil is formed in a substantially rectangular shape with the rear abutting surface 13 being substantially at the center thereof.
It is formed by performing an etching process on a portion excluding 3 and the coil connection terminal 17. The coil forming recess 16 has a groove 16a extending from one end to the terminal groove 31.

Thereafter, a thin film coil 7 is formed in the coil forming recess 16. The thin-film coil 7 has one end 7a disposed on a coil connection terminal 17 and a rear abutting surface 1a.
It has a shape wound many times so as to draw a circle centered at 3. The thin-film coil 7 is drawn out into a groove 16 a formed at one end of the coil forming recess 16, and the other end 7 b is electrically connected to an external connection terminal 18 made of a good conductor filled in a terminal groove 31. Connecting.

When the thin film coil 7 is formed, first, the above-described coil shape is patterned by a photoresist. Next, Cu is formed in the coil forming recess 16.
Is formed into a thin film to a thickness of about 3 μm by a technique such as electrolytic plating. Then, by removing the photoresist, the thin film coil 7 having a patterned coil shape can be formed. In forming the thin-film coil 7, not only the above-described electrolytic plating method but also a sputtering method or a vapor deposition method can be used.

Next, a protective layer (not shown) for protecting the thin-film coil 7 from contact with the outside air is formed. This protective layer is formed so as to bury the coil forming recess 16 in which the above-described thin film coil 7 is formed. The protective layer is preferably formed of a non-magnetic insulating material that is not removed by the oxygen ashing.

Specifically, as a non-magnetic insulating material, Al
Examples thereof include oxides such as ₂ O ₃ , Ta ₂ O ₅ , SiO ₂ , ZrO ₂ , and TiO ₂ and inorganic substances such as glass. Here, as the protective film, Al ₂ O ₃ was sputtered to a thickness of 0.4 μm.
m was formed over the entire surface of the substrate 21. At this time, the protective film also covers the front butting surface 12 and the rear butting surface 13 which are exposed on one main surface of the substrate 21, but the portions covering these portions are removed in a step described later. Note that this protective film can be formed only in a predetermined region by using a so-called mask sputtering method or a lift-off method. Examples of the method for forming the protective film include, besides the sputtering method, an evaporation method and spin coating of coating type SiO ₂ .

Next, as shown in FIG. 11, a side groove 32 which is a square groove is formed so as to cross the front butting surface 12 facing the one main surface in parallel. Then, the magnetic core half 2,
The magnetic core half block 33 is formed by cutting the substrate 21 in which a plurality of rows 3 are formed in parallel so that one magnetic core half 2 and the other magnetic core half 3 are arranged in each row.

The side grooves 32 are formed by grinding, and have a depth of 50 μm and a width of 400 μm, for example. When the side grooves 32 are formed, the side grooves 32
One end of the front abutting surface 12 is exposed on the side surface of. The side grooves 32 are formed to expose the upper end of the front butting surface 12 as a positioning index when the pair of magnetic core half blocks 33 are butted, as described later.

After the side grooves 32 are formed, the one main surface 33a of the magnetic core half-block 33 is polished to be mirror-finished. At this time, the front butting surface 1 covered with the protective film
2 and the rear butting surface 13 are exposed to the outside.

Next, as shown in FIG. 12, a pair of magnetic core half blocks 33 is accurately positioned to perform metal diffusion bonding. At this time, first, a non-magnetic film 8 serving as a gap material for the magnetic core 9 and an adhesive at the time of metal diffusion bonding is formed on one main surface 33a of each of the pair of magnetic core half blocks 33. I do. At this time, the non-magnetic film 8 is formed by a first film forming step of forming the non-magnetic oxide layer 8b on the one main surface 33a and a second film forming step of forming the non-magnetic metal layer 8a. .

Specifically, in the first film forming step, the nonmagnetic oxide layer 8b is formed of SiO ₂ to a thickness of about 10 nm by, for example, a sputtering method. The nonmagnetic oxide layer 8b is formed on one main surface 33 of the pair of magnetic core half blocks 33.
Although it is preferable to be formed on the entire surface of a, it may be formed so as to cover at least the front butting surface 12. As a result, the nonmagnetic oxide layer 8b is different from the nonmagnetic oxide layer 8a in that the front butting surface 1 of the metal magnetic thin film 5 exposed from the one main surface 33a.
2 can be prevented.

The non-magnetic oxide layer 8b is not limited to SiO ₂ but may be at least one material selected from, for example, Al ₂ O ₃ and TiO ₂ . Also,
The method of forming the nonmagnetic oxide layer 8b is not limited to the sputtering method, but may be, for example, an evaporation method. Further, the thickness of the nonmagnetic oxide layer 8b is not limited, and the thickness of the nonmagnetic metal layer 8a is sufficient to prevent the metal magnetic thin film 5 from diffusing to the front butting surface 12, and the gap length is taken into consideration. What is necessary is just to form it.

In the second film forming step, a noble metal such as Au
The nonmagnetic metal layer 8a is formed with a thickness of about m. At this time, the nonmagnetic metal layer 8a is formed in a desired region in consideration of the bonding strength, but may be formed so as to cover at least the front butting surface 12 and the coil connection terminal 17. Since the nonmagnetic metal layer 8a is formed on the metal magnetic thin film 5 via the nonmagnetic oxide layer 8b, the nonmagnetic metal layer 8a does not diffuse into the metal magnetic thin film 5.

The non-magnetic metal layer 8a is not limited to Au, and is formed of a metal having a large diffusion coefficient and having a hardly formed oxide layer on the surface so as to be suitable for metal diffusion bonding at a low temperature. It should be done. Specifically, for example, it may be formed of at least one selected from noble metals such as Ag, Pd, and Pt. The non-magnetic metal layer 8
The method a is not limited to the sputtering method, and may be formed by, for example, an electrolytic plating method, a vapor deposition method, or the like. Further, the thickness of the non-magnetic metal layer 8a is not limited, and may be formed to have a thickness sufficient to perform the metal diffusion bonding of the pair of magnetic core half-blocks 33 and to take the gap length into consideration.

As described above, when the magnetic core half-block 33 is joined, the entire thickness of the nonmagnetic film 8 becomes the gap length of the magnetic core 9 formed by the metal magnetic thin film 5.

In this embodiment, the non-magnetic oxide layer 8b is formed by the first film forming step, and the non-magnetic metal layer 8a is formed by the second film forming step. A third film-forming step of forming a non-magnetic underlayer may be arranged before the film-forming step. In the third film forming step, the bonding strength between the nonmagnetic metal layer 8a and the nonmagnetic oxide layer 8b is increased by forming the nonmagnetic underlayer with at least one selected from, for example, Cr, Ti, and Cu. Can be. Therefore, the non-magnetic film 8 includes the non-magnetic underlayer so that the pair of magnetic core half blocks 3
3 is joined to the nonmagnetic metal layer 8a and the nonmagnetic oxide layer 8a.
It is possible to prevent the film from being peeled off with b, and to reliably integrate the pair of magnetic core half blocks 33.

Since the nonmagnetic underlayer is formed on the metal magnetic thin film 5 via the nonmagnetic oxide layer 8b, it does not diffuse into the metal magnetic thin film 5.

After the nonmagnetic film 8 is formed as described above, the pair of magnetic core half-blocks 33 is accurately positioned to perform metal diffusion bonding.

At this time, the upper ends of the front butting surfaces 12 facing the side grooves 32 are opposed to each other, so that accurate positioning is achieved. In this way, by correctly opposing the upper end of the front butting surface 12 facing the side groove 32, the rear butting surface 13 and the coil connection terminal 17 can be accurately faced.

Then, by applying a predetermined temperature and pressure to the pair of magnetic core half blocks 33 that are abutted, the nonmagnetic metal layers 8b of the nonmagnetic film 8 diffuse, and a pair of magnetic core half A magnetic head block 38 in which the block 33 is joined and integrated is manufactured. In this embodiment, metal diffusion bonding is performed on the pair of magnetic core half blocks 33 at a temperature of 350 degrees.

Next, as shown in FIG. 13, the magnetic head block 38 is separated into the individual magnetic heads 1.

At this time, first, the magnetic head block 38
Is cut in the longitudinal direction in order to expose a surface serving as a sliding surface 10 on which the magnetic recording medium slides. Then, the exposed surface of the magnetic head block 38 is subjected to cylindrical cutting so as to have a cylindrical shape. As a result, this surface becomes the sliding surface 10 of the magnetic head 1. Thereafter, the contact width regulating groove 11 is ground on the magnetic head block 38. The contact width regulating grooves 11 are formed at portions corresponding to both side surfaces of the sliding surface 10 of each magnetic head 1 separated from the magnetic head block 38.

The magnetic head block 38 corresponds to FIG.
3 are separated into individual magnetic heads 1 by cutting at the portion indicated by the line BB.

In the present embodiment, the sliding surface 10 is polished so that the front gap 14 of the magnetic head 1 has an azimuth angle of 20 degrees, and the contact width regulating groove 11 is ground. It is assumed that the cut surface of the magnetic head block 38 is inclined and separated. The magnetic head block 38 performs the above-described polishing of the sliding surface 10, grinding of the contact width regulating groove 11, and cutting of the individual magnetic heads 1 so that the front gap 14 has a predetermined azimuth angle. The azimuth angle is not limited to 20 degrees.

In the present embodiment, the pair of magnetic core half blocks 33 are joined and integrated to form a magnetic head block 38 and then separated into individual magnetic heads 1. After the block 33 is separated into individual magnetic core halves, the magnetic head 1 may be formed by joining and integrating a pair of magnetic core halves.

Hereinafter, a case where a magnetic head as described below is manufactured based on the embodiment of the present invention will be described. Here, the reproduction output of the first magnetic head provided with the nonmagnetic oxide layer with a thickness of 10 nm and the reproduction output of the second magnetic head manufactured without the nonmagnetic oxide layer are compared.

Structure of Non-magnetic Film of First Magnetic Head Non-magnetic metal layer: Au layer (layer thickness: 75 nm) Non-magnetic underlayer: Cr layer (layer thickness: 15 nm) Non-magnetic oxide layer: SiO ₂ layer (layer thickness: 10 nm) Structure of Non-magnetic Film of Second Magnetic Head Non-magnetic metal layer: Au layer (layer thickness: 85 nm) Non-magnetic underlayer: Cr layer (layer thickness: 15 nm) The first magnetic head and the second magnetic head In order to enhance the adhesion of the non-magnetic metal layer, the non-magnetic underlayer is
The thickness was provided. The thickness of the nonmagnetic metal layer was such that the total thickness of the nonmagnetic film was 100 nm. The thickness was 75 nm for the first magnetic head and 85 nm for the second magnetic head.

FIG. 14 shows the reproduced output obtained by using the first magnetic head and the second magnetic head. Also,
The optimum recording currents for the first and second magnetic heads are shown below.

Comparison of optimum recording currents First magnetic head: 23.4 (mVpp) Second magnetic head: 25.7 (mVpp) From the above results, the first magnetic head is different from the second magnetic head. In comparison, the reproduction output is about 2d in all frequency bands.
It turns out that B improved. This is because, in the first magnetic head, the non-magnetic underlayer is prevented from diffusing into the metal magnetic thin film by providing the non-magnetic oxide layer on the non-magnetic film, and the magnetic interface in the magnetic gap is reduced. This is because it was formed clearly.

Further, it can be seen that the first magnetic head can perform recording with a smaller recording current than the second magnetic head. This is because in the first magnetic head, the magnetic interface in the magnetic gap was clearly formed, and the core efficiency was improved.

Next, based on the embodiment of the present invention, it will be evaluated that the nonmagnetic oxide layer of the nonmagnetic film prevents the nonmagnetic underlayer from diffusing into the metal magnetic thin film. Here, a metal magnetic thin film is formed from an Fe-Ta-N alloy on a substrate for an evaluation test, and a non-magnetic film as shown below is formed on the metal magnetic thin film, and the same as in the above-described embodiment. To
The case where the heat treatment is performed at 350 degrees will be described.

Structure of Nonmagnetic Film Nonmagnetic Underlayer: Cr Layer Nonmagnetic Oxide Layer: SiO ₂ Layer Here, the thickness of the nonmagnetic oxide layer in the nonmagnetic film is set to 0.
nm, 1 nm, 2 nm, 4 nm, 7 nm and 10 nm, while performing etching in each case, while performing electron spectroscopy (ESCA: Electr
on Spectroscopy for Chemi
cal Analysis). The state of diffusion of atoms in each case is shown in FIGS. 15, 16, 17, 18, 19, and 20, respectively.

From this result, it can be seen that when the non-magnetic oxide layer is set to 0 nm, the Cr of the non-magnetic underlayer deeply diffuses into the metal magnetic thin film formed of the Fe-Ta-N alloy. However, it can be seen that the diffusion region of Cr to the metal magnetic thin film decreases as the thickness of the nonmagnetic oxide layer increases.

Therefore, it is understood that the nonmagnetic oxide layer can prevent the nonmagnetic underlayer from diffusing into the metal magnetic thin film. In addition, it can be seen that the thickness of the nonmagnetic oxide layer is desirably 4 nm or more in order to ensure the effect of preventing diffusion.

[0092]

As described above, in the magnetic head according to the present invention, the non-magnetic film forming the magnetic gap includes the non-magnetic oxide layer and the non-magnetic metal layer from one main surface of the magnetic core half. They are formed in this order. Therefore, in the magnetic head, the nonmagnetic oxide layer in the nonmagnetic film prevents the nonmagnetic metal layer from diffusing into the metal magnetic thin film formed on the magnetic core half. Therefore, in such a magnetic head, the magnetic interface in the magnetic gap becomes clear, and the head characteristics are improved. As a result, such a magnetic head has excellent recording and reproducing characteristics corresponding to high-density recording.

[Brief description of the drawings]

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

FIG. 2 is a perspective view of a main part showing a sliding surface of the magnetic head.

FIG. 3 is a perspective view of a main part showing a non-magnetic film of the magnetic head.

FIG. 4 is a view for explaining the method for manufacturing the magnetic head according to the present invention, and is a perspective view showing a substrate.

FIG. 5 is a view for explaining the same method, and is a perspective view showing a substrate on which first groove processing has been performed.

FIG. 6 is a diagram for explaining the same method, and is a perspective view showing a substrate on which a metal magnetic thin film is formed.

FIG. 7 is a view for explaining the same method, and is a perspective view showing a substrate on which a second groove processing has been performed.

FIG. 8 is a diagram for explaining the same method, and is a perspective view showing the substrate in a state where each groove is filled with low-melting glass.

FIG. 9 is a diagram for explaining the same method, and is a perspective view showing a substrate in which terminal grooves are formed in low-melting glass.

FIG. 10 is a view for explaining the same method, and is a perspective view of a principal part showing a substrate on which a concave portion for forming a coil is formed.

FIG. 11 is a diagram for explaining the same method, and is a perspective view showing a magnetic core half block.

FIG. 12 is a diagram for explaining the same method, and is a perspective view showing a state where a pair of magnetic core half blocks are butted.

FIG. 13 is a diagram for explaining the same method, and is a perspective view showing a magnetic head block.

FIG. 14 is a characteristic diagram showing characteristics of a reproduction output of a magnetic head depending on the presence or absence of a nonmagnetic oxide layer.

FIG. 15 is a diagram showing diffusion of a nonmagnetic underlayer into a metal magnetic thin film when a nonmagnetic oxide layer is not formed.

FIG. 16 is a diagram showing diffusion of a nonmagnetic underlayer into a metal magnetic thin film when a nonmagnetic oxide layer is 1 nm.

FIG. 17 is a diagram showing diffusion of a nonmagnetic underlayer into a metal magnetic thin film when a nonmagnetic oxide layer is 2 nm.

FIG. 18 is a diagram showing diffusion of a nonmagnetic underlayer into a metal magnetic thin film when a nonmagnetic oxide layer is 4 nm.

FIG. 19 is a diagram showing diffusion of a nonmagnetic underlayer into a metal magnetic thin film when a nonmagnetic oxide layer is 7 nm.

FIG. 20 is a diagram showing diffusion of a nonmagnetic underlayer into a metal magnetic thin film when a nonmagnetic oxide layer is 10 nm.

[Explanation of symbols]

Reference Signs List 1 magnetic head, 2, 3 magnetic core half, 4 non-magnetic substrate, 4a inclined surface, 5 metal magnetic thin film, 5a concave portion, 6
Low melting point glass, 8 non-magnetic film, 8a non-magnetic metal layer, 8
b Non-magnetic oxide layer, 9 magnetic core, 10 sliding surface, 11
Contact width regulating groove, 12 front butting surface, 13 rear butting surface, 14 front gap, 15 back gap, 16 coil forming recess, 18 terminal groove

Continued on the front page (72) Inventor Tadashi Saito 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 5D111 BB12 CC22 DD04 FF12 JJ05 KK05

Claims (5)

[Claims] 1. A pair of magnetic core halves having a metal magnetic thin film formed obliquely on a substrate, having a concave portion in which a thin film coil is formed, and having a butted surface made flat by a nonmagnetic material. A magnetic head in which a magnetic gap is formed by abutting the end faces of the metal magnetic thin film so as to face each other via a non-magnetic film, wherein the non-magnetic film is formed from the butting surface side of the magnetic core half.
A magnetic head comprising a non-magnetic oxide layer and a non-magnetic metal layer formed in this order. 2. The method according to claim 1, wherein the nonmagnetic metal layer comprises Au, Ag, P
2. The magnetic head according to claim 1, wherein the magnetic head is at least one selected from d and Pt. 3. The non-magnetic oxide layer is made of SiO ₂ , Al ₂ O.
_3, the magnetic head according to claim 1, wherein the at least one selected from TiO _2. 4. A non-magnetic underlayer for increasing the adhesion between the non-magnetic oxide layer and the non-magnetic metal layer is provided between the non-magnetic oxide layer and the non-magnetic metal layer. The magnetic head according to claim 1, wherein: 5. The non-magnetic underlayer according to claim 1, wherein the nonmagnetic underlayer comprises Cr, Ti, Cu.
The magnetic head according to claim 4, wherein the magnetic head is at least one selected from the group consisting of: