JPH0652513A - Magnetic head - Google Patents

Abstract

PURPOSE:To form a magnetic head having an excellent quality by obtaining a stable gap length in such a way that the gap sections of magnetic cores are joined to each other by thermally diffusing metallic layers and the other sections of the cores are joined by fused glass, and then, a gap is formed of the metallic layers. CONSTITUTION:Magnetic cores 1 and 2 respectively constituted of magnetic metallic films 5 and 6 and gap materials 7 and 8 formed on substrates 3 and 4 are butted and pressed against each other by using the second metallic layers 7b and 8b of the gap materials 7 and 8 formed of one kind of metal selected from among Au, Ag, Pt, and Pd as joining surfaces. While the cores 1 and 2 are pressed against each other, fused glass is put in winding grooves 11 and 12 and glass grooves 13 and 14 and heated to the welding temperature of the glass. Therefore, since a gap is formed by joining the cores 1 and 2 to each other by means of the thermal diffusion of the metallic layers 7b and 8b on the butting surfaces of the cores 1 and 2 and fused glass 9b and l0b in the grooves 11 and 12 and 13 and 14, a stable gap length can be obtained and a magnetic head having an excellent performance can be formed.

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 pair of magnetic cores joined together with a gap portion, and more particularly to a method of joining a pair of magnetic cores.

[0002]

2. Description of the Related Art For example, as a magnetic head incorporated in a magnetic recording / reproducing device such as a VTR (video tape recorder), an oxide magnetic material for forming a magnetic core is, for example, a single crystal ferrite, a polycrystalline ferrite or a single crystal ferrite. A ferrite head using a joining material of polycrystalline ferrite is generally used. Further, in the above magnetic recording / reproducing apparatus, the recording of information signals with a shorter wavelength is being promoted for the purpose of improving the image quality. Various magnetic heads using a magnetic metal body as a magnetic core have been developed. A typical example of such a magnetic head is a composite type magnetic head of an oxide substrate such as ferrite and a metal magnetic material, a so-called metal-in-gap (Me).
tal in gap) head (hereinafter, abbreviated as MIG head).

For example, the MIG head has a magnetic gap g ₅ (front gap), as shown in FIG.
A pair of magnetic cores 61 and 62, which are separately formed on the left and right sides of a magnetic gap g ₆ (back gap) as a boundary, are abutted and joined together with a gap portion, and the magnetic cores 61 and 62 are made of ferrite or the like. Substrates 63 and 64 made of oxide magnetic material and metal magnetic films 65 and 66. Magnetic gaps g ₅ and g ₆ are formed on the upper and lower abutting surfaces of the magnetic cores 61 and 62, and winding grooves 67 and 68 for winding coils on the substrates 63 and 64, and glass for glass fusion. Grooves 69 and 70 are formed, and winding grooves 67 and 68 are formed.
And the glass grooves 69, 70 between the fused glass 71b, 72
It is joined by b. At this time, the metal magnetic film 65,
66 is the winding groove 6 from the abutting surface of the upper part of the substrates 63 and 64.
Through the inside of 7,68, the lower butting surface, the glass grooves 69,7
The magnetic cores 61 and 62 are formed along the shape of the substrates 63 and 64 to 0. Similarly, in the case of the ferrite head, a pair of magnetic cores are bonded together with a gap portion, and the magnetic cores are made of single crystal ferrite, polycrystalline ferrite, a bonding material of single crystal ferrite and polycrystalline ferrite, or the like. It is made of an oxide magnetic material.

Ferrite heads and MIG heads in which such a pair of magnetic cores are joined together having a gap portion are manufactured by the method described below. For example, in an MIG head, as shown in FIG. 16A, ferrite having a butting surface formed with winding grooves 67, 68 and glass grooves 69, 70 in parallel with the magnetic gaps g ₅ , g ₆ , etc. Of the magnetic cores 61 and 62 having metal magnetic films 65 and 66 formed on the opposite surfaces of the substrates 63 and 64 made of the oxide magnetic material of the above, along the shapes of the substrates 63 and 64, by vapor deposition, sputtering, etc. Forming a spacer 73 made of an oxide such as SiO by the method of
The magnetic cores 61 and 62 are butted against each other through the winding groove 6
Fused glass 71 in glass grooves 69, 70 in 7, 68
a and 72a are arranged and pressurized and heated. Magnetic core 61,6
2 is fused glass 71b, 7b as shown in FIG. 16B.
It is joined and integrated via 2b. After that, processing such as cylindrical polishing and chip cutting is performed, and the MI as shown in FIG.
Get the G head. Therefore, in the magnetic head formed by this method, the magnetic gaps g ₅ and g ₆ are made of glass.

The MIG head as described above is also manufactured by the following method. As shown in FIG. 17A, substrates 63, 6 made of an oxide magnetic material such as ferrite in which winding grooves 67, 68 and glass grooves 69, 70 are formed.
Si is formed on the entire abutting surface of the magnetic cores 61 and 62 formed by forming metal magnetic films 65 and 66 along the shapes of the substrates 63 and 64 on the opposing surface of No. 4 by a method such as vapor deposition or sputtering.
A gap member 74 made of an oxide such as O ₂ is formed, the magnetic cores 61 and 62 are abutted through the gap member 74, and the winding groove 67,
68 and glass grooves 69, 70 in the fused glass 71a, 7
2a is placed and pressure heating is performed. The magnetic cores 61 and 62 are
As shown in FIG. 17B, they are joined and integrated through the fused glass 71b, 72b. Thereafter, processing such as cylindrical polishing and chip cutting is performed to obtain an MIG head as shown in FIG. Therefore, in the magnetic head formed by this method, the magnetic gaps g ₅ and g ₆ are formed by the gap material.

A ferrite head whose magnetic core is formed of a bonding material of single crystal ferrite, polycrystalline ferrite, single crystal ferrite and polycrystalline ferrite is also manufactured by the manufacturing method such as the above two methods.

[0007]

However, magnetic heads such as ferrite heads and MIG heads formed by the above method have the following problems. That is, in the first method, the spacer is made of oxide such as SiO 2 so that the gap portion is made of glass, so that the gap length is changed by diffusion of the fused glass. In the MIG head described above, since the diffusion easily occurs between the metal magnetic film formed on the oxide substrate and the fused glass, the accuracy of the gap length is not good and the manufacturing yield is reduced. Further, when the magnetic head is formed by the second method, an oxide such as SiO ₂ is used as a gap material, the magnetic cores are abutted through the gap material, and the other portions are bonded by the fused glass. In the ferrite head and the MIG head formed by this method, the gap portion is not joined, so that the joining strength is low, cracks occur in the glass fused portion of the magnetic head, and the manufacturing yield decreases. Is occurring.

Therefore, it is an object of the present invention to provide a magnetic head which can obtain a stable gap length, has high bonding strength, good quality, and can improve the manufacturing yield. .

[0009]

In order to achieve the above object, the present invention provides a magnetic head in which a pair of magnetic cores are joined together with a gap portion, and Au, Ag are attached to the joining surfaces of the respective magnetic cores. , Pt, Pd, a metal layer made of one kind of metal is formed, the gap portion of the magnetic core is joined by thermal diffusion of the metal layer, and the other portion is joined by a fused glass. It is a feature.

[0010]

According to the present invention, in a magnetic head in which a pair of magnetic cores are joined with each other with a gap portion, a metal made of one kind of metal selected from Au, Ag, Pt and Pd is formed on the joining surface of each magnetic core. A layer is formed, the gap portion of the magnetic core is joined by thermal diffusion of the metal layer, and the other portion is joined by the fused glass. It is possible to obtain a high joining strength because not only the gap portion but also other portions are joined.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. Example 1 In this example, an example of a so-called MIG head in which a magnetic core is composed of an oxide substrate and a metal magnetic film will be described.

As shown in FIG. 1, the magnetic head of this embodiment has substrates 3, 4 made of an oxide magnetic material such as ferrite.
A pair of magnetic cores 1 and 2 having metal magnetic films 5 and 6 adhered to the opposing surfaces of the two are bonded together by using gap materials 7 and 8 and fused glass 9b and 10b. A magnetic gap g ₁ (front gap) and a magnetic gap g ₂ (back gap) are formed on the abutting surfaces of the magnetic cores 1 and ₂ to form a closed magnetic circuit.
A winding groove 1 for winding a coil is provided on the substrates 3 and 4.
1, 12 and glass grooves 13, 14 are formed, and the metal magnetic films 5, 6 and the gap materials 7, 8 are formed along the shapes of the substrates 3, 4.

For the metal magnetic films 5 and 6, for example, any of the following materials can be used. For example, F
e-Al-Si system, Fe-Ga-Si system crystal material and Fe
-N-based, Fe-C-based microcrystalline materials and Co-Zr-based, Co
—Nb-based amorphous materials and the like. The metal magnetic films 5 and 6 are deposited on the substrates 3 and 4 by a vacuum thin film forming technique typified by, for example, a sputtering method or a vacuum deposition method.

Further, the gap materials 7 and 8 are formed on the joint surfaces of the magnetic cores 1 and 2 on which the metal magnetic films 5 and 6 are formed, respectively. However, in the magnetic head of this embodiment, the gap is formed. As shown in FIG. 2, the materials 7 and 8 are C
r, Ti, Mo, W, Mn, Fe, Co, Ni, Al,
First metal layers 7a and 8a made of at least one metal selected from Ta, Cu, Au, and Ag and oxides or nitrides of these metals, and Au, Ag,
The second metal layers 7b and 8b are made of one kind of metal of Pt and Pd. These first metal layers 7a, 8a,
The second metal layers 7b and 8b are laminated by a vacuum thin film forming technique typified by a sputtering method or a vacuum vapor deposition method. At this time, the total thickness of the gap members 7 and 8 corresponds to the magnetic gaps g ₁ and g ₂ . Therefore,
The thicknesses of the first metal layers 7a and 8a and the second metal layers 7b and 8b are the sum of the first metal layer 7a and the second metal layer 7b, and the first metal layer 8a and the second metal layer. It may be determined so that the sum of the film thicknesses of 8b corresponds to 1/2 of the predetermined magnetic gaps g ₁ and g ₂ . However, the film thickness of the first metal layers 7a and 8a is 10 nm or more, and the film thickness of the second metal layers 7b and 8b is 2 nm or more.
It is preferably 0 nm or more.

In the magnetic head of this embodiment,
If necessary, an underlying layer such as a SiO ₂ layer may be provided between the metal magnetic films 5 and 6 of the magnetic cores 1 and 2 and the first metal layers 7a and 8a.

Further, in the magnetic head of this embodiment, the magnetic cores 1 and 2 are joined by the fused glass 9b and 10b. The fusing glasses 9b and 10b may be any as long as they are commonly used for manufacturing a magnetic head.

In the magnetic head of the present embodiment as described above, the magnetic cores 1 and 2 having the metal magnetic films 5 and 6 and the gap members 7 and 8 formed on the substrates 3 and 4 are arranged on the substrates 3 and 4, respectively. The two metal layers 7b and 8b are abutted against each other as a joint surface and pressed, and the fused glass is placed in the winding grooves 11 and 12 and the glass grooves 13 and 14 in the pressurized state until the fusion temperature of the fused glass is reached. By raising the temperature, the magnetic cores 1 and 2 are joined to the abutting surface by the second metal layers 7b and 8b by thermal diffusion, and the winding groove 11 is formed.
12 and the glass grooves 13 and 14 are formed by joining the magnetic cores 1 and 2 by joining the fused glass 9b and 10b.

When the substrates 3 and 4 are made of ferrite, the whole substrate is made of single-crystal ferrite or polycrystalline ferrite, or only the tip portion of the front gap in the substrate is made of single-crystal ferrite. It suffices to use a bonding material whose rear part is made of polycrystalline ferrite.
When a single crystal ferrite is used, as shown in FIG. 3A (in the figure, the substrates 3 and 4 made of a bonding material of a single crystal ferrite and a polycrystalline ferrite are shown), and the medium facing surface of the substrate 3. 3a and one side surface 3b orthogonal thereto are constituted by (1,1,0) planes of single crystal ferrite, and another side surface 3c orthogonal to the medium facing surface 3a is constituted by (1,0,0) planes of single crystal ferrite. Be composed of faces,
The substrate 4 is also configured in the same manner and is a so-called B-type ferrite, or as shown in FIG. 3B, the medium facing surface 3a of the substrate 3 is a (2,1,1) surface, and one side surface orthogonal to the (2,1,1) surface. 3b is composed of the (1,1,0) plane of the single crystal ferrite, and another side surface 3c orthogonal to the medium facing surface 3a is composed of the (1,1,1) plane of the single crystal ferrite. A so-called J-type ferrite may be used with the same structure.

When mass-producing the magnetic head having the above-mentioned structure, the magnetic head is manufactured according to the following steps. First, as shown in FIG. 4, one magnetic core 1
In order to form the substrate 3, a block 15 made of ferrite or the like is prepared, a plurality of H-grooves 16 having a substantially semicircular cross section for regulating the track width of the substrate 3 are formed, and then a coil is wound. H of the winding groove 11 having a substantially trapezoidal cross section and the glass groove 13 having a substantially trapezoidal cross section for performing glass fusion bonding.
It is formed so as to be orthogonal to the groove 16, and the gap forming surface 15a of the block 15 is mirror-finished. At this time, the winding groove 11
The depth of the gap portion of the substrate 3 is determined by this, the magnetic gap g ₁ (front gap) depth (depth) of the magnetic core 1 to be formed is regulated, and the fused glass is arranged in the winding groove 11. In order to improve the adhesive strength between the magnetic cores 1 and 2, the tip of the inclined portion of the winding groove 11 is formed on the substrate 3
The winding groove 11 is formed so as to reach a position where the depth of the gap portion is zero. The same applies to the glass groove 13, and the depth of the gap portion of the substrate 3 is determined by the glass groove 13, and the magnetic gap g ₂ (back gap) depth (depth) of the magnetic core 1 to be formed is regulated. In addition, in order to improve the adhesive strength between the magnetic cores 1 and 2 by arranging the fused glass in the glass groove 13,
The glass groove 13 is formed so that the tip end of the inclined portion corresponds to the position where the depth of the gap portion becomes zero.

Next, as shown in FIG. 5, the block 15 having the winding groove 11, the glass groove 13, and the H groove 16 is formed.
Then, the metal magnetic film 5 is formed by a sputtering method or the like. Then, the gap material 7 is formed on the metal magnetic film 5. The gap material 7 is formed by sequentially depositing the first metal layer 7a and the second metal layer 7b by a sputtering method or the like.

Then, the winding groove 1 serving as one of the magnetic cores 1
1, the glass groove 13 and the H groove 16 are formed, and the metal magnetic film 5 is formed.
The block 15 on which the gap material 7 is formed by film formation and the block to be the other magnetic core 2 manufactured in the same manner as this are joined. That is, as shown in FIG.
A block 15 in which a winding groove 11, a glass groove 13, and an H groove 16 are formed, and a metal magnetic film 5 and a gap material 7 are formed and formed.
A block 1 on which a winding groove 12, a glass groove 14, and an H groove 17 are formed, and a metal magnetic film 6 and a gap material 8 are formed.
8 is a gap material 7, 8 is a butt surface, and winding groove 11,
12, the glass grooves 13 and 14, and the H grooves 16 and 17 are butted so that the positions thereof match. The blocks 15 and 18 are held by a jig or the like, pressure is applied at a pressure of about 10 MPa, and the fused glass 9a and 10a are arranged in the winding grooves 11 and 12 and the glass grooves 13 and 14, respectively. Fused glass 9
a, 10a are heated to the fusion temperature, and the second metal layers 7b, 8b in the portions where the gap materials 7, 8 are in contact are thermally diffused and arranged in the winding grooves 11, 12 and the glass grooves 13, 14. When the fused glass 9a, 10a is melted, the block 15,
Join 18 to obtain block 19. At this time, if the heat treatment as described above is performed in vacuum, stronger joint strength can be obtained. In the block 19 thus obtained, the magnetic gap g ₁ (front gap) and the magnetic gap g ₂ (back gap) are formed by the gap members 7 and 8.
Are formed.

Finally, the magnetic gap g ₁ of the block 19
The forming surface 19a is subjected to cylindrical polishing and the chips are cut to obtain a magnetic head as shown in FIG.

Therefore, the relationship between the gap length determined by the film thickness of the gap material and the effective gap length of the magnetic head of the magnetic head manufactured by the above-described process was investigated. A cross-sectional view and a side view of one magnetic core 2 of the magnetic head manufactured in this embodiment are shown in FIG.
8 shows. In this embodiment, as shown in FIG. 8, the depth d of the magnetic gap g ₁ (front gap) is 0.02.
mm, the width W is 0.100 mm, the depths a and c of the fused glass 9 and 10 are 0.250 mm, the depth b of the magnetic gap g ₂ (back gap) is 1.00 mm, and the magnetic core 2 is The width e was set to 0.200 mm, the film thickness t of the gap material 8 shown in FIG. 7 was changed, and the relationship between the gap length 2t and the effective gap length was investigated.

The block is formed of ferrite, the sendust film is formed as the metal magnetic film, the Cr layer is formed as the first metal layer of the gap material, the Au layer is formed as the second metal layer, and the fused glass is formed by fusion. Glass having a temperature of 670 ° C. is used, and when the Cr layer that is the first metal layer and the Au layer that is the second metal layer of the gap material are formed by the sputtering method, the film thickness is changed to have various gap lengths. The magnetic heads as described above were manufactured, and the effective gap lengths of these magnetic heads were measured. The results are shown in Fig. 9. As can be seen from FIG. 9, the gap length determined by the film thickness of the gap material and the effective gap length are substantially the same, and when measured with one type of magnetic head at n = 40, the variation is ± It was about 0.02 μm, and it was confirmed that a stable gap length was obtained in the magnetic head of the present embodiment.

Further, the magnetic head of this embodiment and the conventional Si
Comparing the bonding area of the magnetic head having the same shape as that of the present example in which the gap portion is formed of the oxide material such as O ₂ and the other portion is fusion-bonded with the fused glass, the magnetic field of this example is The head was 0.299 mm ² , and the conventional magnetic head was 0.097 mm ² , and it was confirmed that the magnetic head of this example had a bonding area about three times that of the conventional magnetic head, and the bonding strength was improved. It seems that

The shape of the magnetic head of the present invention is not limited to that described above, but both ends of the abutting surfaces of the substrates 23 and 24 of the magnetic cores 21 and 22 as shown in FIG. 10 are notched in a substantially fan shape. The metal magnetic films 25 and 26 and the gap members 27 and 28 are formed along the shapes of the substrates 23 and 24, and the width of the magnetic gap g ₇ (front gap) is narrower than the width of the magnetic cores 21 and 22. But good. In such a type of magnetic head, the magnetic core 2 corresponding to the cutouts at both ends of the abutting surfaces of the substrates 23 and 24.
The problem that the recording medium contacting the magnetic head is ground by the ends of the magnetic heads 1 and 22 has occurred, but in the magnetic head of this embodiment, the substrates 23 and 2 are formed as shown in FIG.
Since the fused glass 29 is filled in the end portions of the magnetic cores 21 and 22 corresponding to the cutout portions of No. 4, the above-mentioned problem is solved.

In the magnetic head of the present invention, both ends of the abutting surface of the substrate 33 of one magnetic core 31 as shown in FIG. 11 are cut out in a substantially fan shape, and the other magnetic core 32 is formed.
The abutting surface of the substrate 34 of is a shape not cut out,
Along the shape of these substrates 33, 34, the metal magnetic film 35,
36 and gap members 37, 38 are formed, and the width of the magnetic gap g ₈ (front gap) is the magnetic core 31,
A type narrower than the width of 32 may be used. In this type of magnetic head as well, there has been a problem that the recording medium in contact with the magnetic head is ground by the end portions of the magnetic core 31 corresponding to the cutout portions at both ends of the abutting surface of the substrate 33. In the magnetic head of this embodiment, as shown in FIG. 11, since the fused glass 39 is filled in the end portion of the magnetic core 31 corresponding to the cutout portion of the substrate 33, the above-mentioned problem occurs. Is eliminated.

Example 2 In this example, a so-called ferrite head in which the magnetic core is made of an oxide magnetic material such as a single crystal ferrite, a polycrystalline ferrite, or a bonding material of the single crystal ferrite and the polycrystalline ferrite will be described. . As shown in FIG. 12, the magnetic head of the present embodiment has a pair of magnetic cores 4 made of an oxide magnetic material such as single crystal ferrite, polycrystalline ferrite, or a bonding material of single crystal ferrite and polycrystalline ferrite.
1, 42 are joined using the gap members 43 and 44,
In addition, they are joined together by using fused glass 45b and 46b, and a magnetic gap g ₃ (front gap) and a magnetic gap g ₄ (back gap) are formed on the abutting surfaces of the magnetic cores 41 and 42. , A closed magnetic circuit is configured. Winding grooves 47, 48 and glass grooves 49, 50 for winding the coils are formed in the magnetic cores 41, 42, and the gap members 43, 44 follow the shape of the magnetic cores 41, 42. Is formed.

In the magnetic head of this embodiment, the gap members 43 and 44 are made of Cr, as shown in FIG.
Ti, Mo, W, Mn, Fe, Co, Ni, Al, T
a, Cu, Au, Ag, at least one kind of metal and oxides and nitrides thereof, and further SiO ₂ ,
First metal layers 43a and 44a made of an oxide or nitride such as SiN and formed as an underlayer, and Au, Ag, and P.
Second metal layer 4 made of one kind of metal of t and Pd
3b and 44b. These first metal layers 43a, 4
The 4a and the second metal layers 43b and 44b are laminated by a vacuum thin film forming technique typified by a sputtering method or a vacuum evaporation method. At this time, the total film thickness of the gap materials 43 and 44 corresponds to the magnetic gaps g ₃ and g ₄ . Therefore, the film thicknesses of the first metal layers 43a and 44a and the second metal layers 43b and 44b are the sum of the first metal layer 43a and the second metal layer 43b, and the first metal layer 44a and the second metal layer 43b.
The sum of the film thicknesses of the metal layers 44b of the predetermined magnetic gap g ₃ ,
It may be determined so as to correspond to ½ of the g ₄ length. However, the film thickness of the first metal layers 43a and 44a is preferably 10 nm or more, and the film thickness of the second metal layers 43b and 44b is preferably 20 nm or more.

Further, in the magnetic head of this embodiment,
The magnetic cores 41 and 42 are joined by fused glass 45b and 46b. The fused glass 45b and 46b are
Any one can be used as long as it is one that is usually used for manufacturing a magnetic head.

In the magnetic head of the present embodiment as described above, the magnetic cores 41, 42 are butted against each other with the second metal layers 43b, 44b of the gap members 43, 44 as the joint surfaces, pressed, and kept in the pressed state. Winding grooves 47, 48 and glass grooves 49, 50
The fusion glass is placed on the magnetic field, and the temperature is raised to the fusion temperature of the fusion glass, so that the magnetic cores 41 and 42 are joined by the heat diffusion by the second metal layers 43b and 44b on the abutting surface and the winding groove 47. , 48 and glass grooves 49, 50 fused glass 45
It is formed by joining the magnetic cores 41 and 42 by joining with b and 46b.

In the magnetic head of this embodiment, single crystal ferrite, polycrystalline ferrite, and
Alternatively, a bonding material is used in which only the front end portion forming the front gap in the substrate is made of single crystal ferrite and the rear portion is made of polycrystalline ferrite. When the single crystal ferrite is used, the magnetic core of the magnetic core is used as in the first embodiment. The medium facing surface and one side surface orthogonal to the medium facing surface are constituted by (1,1,0) surfaces, and the other side surface perpendicular to the medium facing surface are constituted by a (1,0,0) surface, and the other side surface is constituted. The magnetic core of No. 1 is also configured in the same manner and is a so-called B-type ferrite, or the medium facing surface of the magnetic core is the (2,1,1) surface and one side surface orthogonal to this is (1,1,0). The surface, the other side surface orthogonal to the medium facing surface may be formed of the (1,1,1) surface, and the other magnetic core may be formed in the same manner, so-called J-type ferrite.

When mass-producing the magnetic head having the above-described structure, as in the first embodiment, a block made of ferrite is prepared to form one magnetic core 41, and the track of the magnetic core 41 is prepared. A plurality of H-grooves having a substantially semicircular cross section for restricting the width are formed, and then a winding groove 47 having a substantially trapezoidal cross section for winding a coil next, a substantially trapezoidal cross section for performing glass fusion bonding. The glass groove 49 is formed so as to be orthogonal to the H groove, and the gap forming surface of the block is mirror-finished. Then, the gap material 43 is formed in the block in which the winding groove 47, the glass groove 49, and the H groove are formed.
The gap material 43 is formed by sequentially depositing the first metal layer 43a and the second metal layer 43b by a sputtering method or the like.

Then, as shown in FIG. 14, a winding groove 47, a glass groove 49, and an H groove 52 which are to be one of the magnetic cores 41 are formed, and the block 51 on which the gap material 43 is formed is formed. The other magnetic core 4 produced in the same manner
The winding groove 47, the glass groove 50, and the H groove 53, which are two, are formed, and the block 54 on which the gap material 44 is formed is formed by using the gap materials 43 and 44 as the abutting surfaces.
8. Butt the glass grooves 49, 50 and the H grooves 52, 53 so that the positions thereof match. The blocks 51 and 54 are held by a jig or the like, and a pressure of about 10 MPa is applied,
Fusing glass 45a and 46a are arranged in the winding grooves 47 and 48 and the glass grooves 49 and 50, and the fusion glass 45 is kept in a pressurized state.
a, 46a to the fusion temperature of the gap material 43, 4
The blocks 51 and 54 are formed by heat diffusion of the second metal layers 43b and 44b in contact with 4 and melting of the fused glass 45a and 46a arranged in the winding grooves 47 and 48 and the glass grooves 49 and 50. Bonding to obtain block 55. At this time, if the heat treatment as described above is performed in vacuum, stronger joint strength can be obtained. In the block 55 thus obtained, the magnetic gap g ₃ (front gap) and the magnetic gap g are formed by the gap members 43 and 44.
₄ (back gap) is formed.

Finally, the magnetic gap g ₃ of the block 55 is
The forming surface 55a is subjected to cylindrical polishing, and the chips are cut, as shown in FIG.
A magnetic head as shown in FIG.

Therefore, with respect to the magnetic head manufactured by the above process, the relationship between the gap length determined by the film thickness of the gap material and the effective gap length of the magnetic head was investigated as in the first embodiment. However, the gap length determined by the thickness of the gap material and the effective gap length are substantially the same, and when measured with one type of magnetic head at n = 40, the variation is ± 0.02.
It was confirmed that a stable gap length was obtained in the magnetic head of this example.

Further, the magnetic head of this embodiment and the conventional Si
Comparing the bonding area of the magnetic head having the same shape as that of the present example in which the gap portion is formed of the oxide material such as O ₂ and the other portion is fusion-bonded with the fused glass, the magnetic field of this example is It was confirmed that the head has a bonding area about three times that of the conventional magnetic head, and it is considered that the bonding strength is improved.

The shape of the magnetic head of the present invention is not limited to the above-described one, and as in the first embodiment, both ends of the abutting surfaces of the pair of magnetic cores are cut out in a substantially fan shape to form a magnetic gap (front gap). The width of) may be narrower than the width of the magnetic core. In such a type of magnetic head, there is a problem that the recording medium in contact with the magnetic head is ground by the end portions of the magnetic core corresponding to the cutout portions at both ends. However, in the magnetic head of this embodiment, ,
Since the fused glass is filled in the end portion of the magnetic core corresponding to the cutout portion, the above-mentioned problem is solved.

In the magnetic head of the present invention, both ends of the abutting surface of one magnetic core are cut out in a substantially fan shape, and the abutting surface of the other magnetic core is not cut out.
A type in which the width of the magnetic gap (front gap) is narrower than the width of the magnetic core may be used. In this type of magnetic head as well, there was a problem that the recording medium in contact with the magnetic head was ground by the ends of the one magnetic core corresponding to the notches at both ends of the abutting surface. In the magnetic head of the example, since the fused glass is filled in the end portion of the magnetic core corresponding to the cutout portion, the above-mentioned problem is solved.

[0040]

As is apparent from the above description, in the present invention, in a magnetic head in which a pair of magnetic cores are joined with each other with a gap portion, the joining surface of each magnetic core is A.
A metal layer made of one kind of metal selected from u, Ag, Pt, and Pd is formed, the gap portion of the magnetic core is joined by thermal diffusion of the metal layer, and the other portion is joined by fused glass. Since a gap is formed by the metal layer, a stable gap length can be obtained, and since not only the gap portion but also other portions are joined, it is possible to obtain high joining strength. It is possible to obtain an improved magnetic head. Further, this improves the accuracy of the gap during manufacturing, and the magnetic head is not damaged during manufacturing, so that the manufacturing yield can be improved, and its industrial value is very high.

Further, in the present invention, in the above magnetic head, the magnetic core may be a magnetic core composed of an oxide substrate and a metal magnetic film, and a magnetic head capable of supporting short wavelength recording can be obtained. And its industrial value is very high.

Furthermore, in the present invention, in the magnetic head as described above, the magnetic core may be formed of an oxide magnetic material, the productivity is good, and the industrial value thereof is very high.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a magnetic head to which the present invention is applied.

FIG. 2 is a sectional view showing an example of a magnetic head to which the present invention is applied.

FIG. 3 is a perspective view showing a crystal plane when ferrite is used as a substrate in a magnetic head to which the present invention is applied.

FIG. 4 is a perspective view showing an example of steps of manufacturing a magnetic head to which the present invention is applied, in the order of steps, showing steps of forming an H groove, a winding groove, and a glass groove in a block.

FIG. 5 is a perspective view showing a step of forming a metal magnetic film and a gap material in a block in which an H groove, a winding groove and a glass groove are formed.

FIG. 6 is a perspective view showing a step of joining two blocks in which an H groove, a winding groove, and a glass groove are formed, and a metal magnetic film and a gap material are formed.

FIG. 7 is a cross-sectional view showing one magnetic core of the magnetic head manufactured in the example.

FIG. 8 is a side view showing one magnetic core of the magnetic head manufactured in the example.

FIG. 9 is a diagram showing the relationship between the gap length determined by the film thickness of the gap material of the magnetic head manufactured in the example and the effective gap length of the magnetic head.

FIG. 10 is a top view showing another embodiment of the magnetic head to which the present invention is applied.

FIG. 11 is a top view showing still another embodiment of the magnetic head to which the present invention is applied.

FIG. 12 is a perspective view showing still another example of a magnetic head to which the present invention is applied.

FIG. 13 is a sectional view showing another example of a magnetic head to which the present invention is applied.

FIG. 14 is a perspective view showing a step of joining two blocks in which an H groove, a winding groove, and a glass groove are formed, and a metal magnetic film and a gap material are formed in a process of manufacturing a magnetic head to which the invention is applied. Is.

FIG. 15 is a perspective view showing an example of a conventional magnetic head.

FIG. 16 is a cross-sectional view showing an example of a conventional magnetic head manufacturing method.

FIG. 17 is a cross-sectional view showing another example of the conventional method of manufacturing a magnetic head.

[Explanation of symbols]

1, 2, 41, 42 ... Magnetic core 3, 4 ... Substrate 5, 6 ...・ ・ ・ Metallic magnetic film 7,8,43,44 ・ ・ ・ ・ Gap material 7a, 8a, 43a, 44a ・ ・ ・ First metal film 7b, 8b, 43b, 44b・ ・ ・ Second metal film 9b, 10b, 45b, 46b ・ ・ ・ ・ Fused glass 11, 12, 47, 48 ・ ・ ・ Winding groove 13, 14, 49, 50 ・ ・・ ・ ・ Glass groove g ₁ , g ₂ , g ₃ , g ₄・ ・ ・ Magnetic gap

Front Page Continuation (72) Inventor Atsushi Suzuki 6-735 Kitashinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Toshihiro Hashishita Inventor Toshihiro Hashishita 6-35 Kitashinagawa, Shinagawa-ku, Tokyo Sony Corporation Shares In-house (72) Inventor Hideaki Karamon 6-735 Kitashinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (3)

[Claims] 1. In a magnetic head in which a pair of magnetic cores are joined with each other with a gap portion, a metal layer made of one kind of metal of Au, Ag, Pt, and Pd is formed on a joining surface of each magnetic core. The magnetic head is characterized in that the gap portion of the magnetic core is joined by thermal diffusion of the metal layer and the other portion is joined by the fused glass. 2. The magnetic head according to claim 1, wherein the magnetic core is a magnetic core composed of an oxide substrate and a metal magnetic film. 3. The magnetic head according to claim 1, wherein the magnetic core is made of an oxide magnetic material.