JP2000076614A - Magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent leakage of magnetic flux and to improve core efficiency per inductance by forming depth confirming groove parts of a magnetic gap on magnetic core half bodies nearly parallel to a medium slide surface so that front butt surfaces are notched, and its both end are faced to both side surfaces of core half bodies and filling up conductive material showing non-magnetism in the groove part. SOLUTION: The groove part 18 as a depth marker deciding the depth zero position 13a of the front gap 13 is formed for precisely and easily reading the depth B being the depth from the slide surface 9 of the front gap 13. The groove part 18 is formed nearly parallel to the slide surface 9 so that the front butt surfaces of a pair of core half bodies are notched, and its both end are faced to both end surfaces of a magnetic head. The conductive material 19 showing the non-magnetism such as Cu is filled up in the groove part 18, and the leakage of the magnetic flux generated in the magnetic core on the groove part 18 is prevented, and the magnetic flux is made to flow convergently through the front gap 13 to reduce the inductance.

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 metallic magnetic thin film, and more particularly, to a magnetic head having a depth marker for confirming the depth of a magnetic gap.

[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 magnetic head, a pair of magnetic core halves each having a metal magnetic thin film formed as a magnetic core on a non-magnetic substrate are bonded and integrated by metal diffusion bonding via a non-magnetic material. A magnetic gap is formed on the surface. 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. .

In the magnetic head, the depth of the magnetic gap, called the depth, from the sliding surface of the medium is one of the important factors that determine the head characteristics, and a pair of magnetic core halves are joined. After the integration, the depth of the magnetic gap is adjusted by polishing the medium sliding surface.

[0009] For example, FIG.
As shown in (B), as a first method for confirming the depth F of the magnetic gap, the above-described MIG type magnetic head 10 is used.
0, light is emitted from one side of the magnetic head 100, and an image projected by transmitting the light through the glass-filled portion 101 of the magnetic head 100 is displayed on the other side of the magnetic head 100 by a metal microscope. A method of confirming using 102 or the like is generally used.

However, FIG. 16A and FIG.
As shown in (B), when this first method is used for the bulk thin film magnetic head 103, the pair of magnetic core halves are joined and integrated by metal diffusion bonding as described above. Therefore, there is a problem that transmission of light is blocked by the metal film 104 formed on the bonding surface, and the depth F of the magnetic gap 103 cannot be confirmed.

As shown in FIGS. 17 (A) and 17 (B), as a second method for confirming the depth F of the magnetic gap, a photolithography technique is used for the joint surface of the magnetic core half. A marker 10 having a height dimension equal to the depth F of the magnetic gap 105 and having a predetermined hearing and a triangular cross section.
6 is formed such that its base is exposed on the medium sliding surface;
A method of measuring the length H of the bottom portion of the marker 106 exposed from the medium sliding surface is also known.

In the second method, the depth F of the magnetic gap 105 is calculated by measuring the length H of the bottom portion of the marker 106 exposed from the medium sliding surface. The present invention can be applied to a case where it is difficult to confirm the depth F of the magnetic gap 105 from the side of the head, such as a magnetic head.

However, in the second method, it is very difficult to align the tip of the marker 106 with the end of the magnetic gap 105, and it is difficult to accurately check the depth F of the magnetic gap 105. That is, the marker 106 is formed on the bonding surface of the magnetic core half by etching using the photolithography technique, and an error of about ± 2 μm may occur in the formation position due to variation in patterning and variation in etching. . Therefore, in this second method, the magnetic gap 1
However, the depth F of the magnetic gap 105 cannot be confirmed accurately, and it is difficult to adjust the depth F of the magnetic gap 105 by polishing the medium sliding surface with high accuracy.

[0014]

Therefore, as a third method, as described in Japanese Patent Application No. 9-59652, entitled "Magnetic Head and Manufacturing Method therefor", the present inventors have proposed a method of forming a magnetic gap having a depth. By forming a groove serving as a depth marker for confirming the gap on the side surface of the magnetic core half as desired, a magnetic head capable of easily confirming the gap depth by visual inspection and a method of manufacturing the same are proposed. I have.

According to the third method, in the magnetic head, the depth of the magnetic gap can be easily confirmed by reading the position of the depth marker. According to the third method, the depth of the magnetic gap can be adjusted with high precision by polishing the medium sliding surface with reference to the position of the depth marker.

However, this third method requires high-precision machining in order to match the groove serving as a depth marker with the zero depth position of the magnetic gap. This third
Method does not perform high-precision processing, and if any error occurs in the position where the groove is formed, the error directly becomes an error between the depth read by the depth marker and the actual depth. There was such a problem.

Therefore, in the third method, it is necessary to form the groove so as to cut off the end of the magnetic gap so that the position of the groove is surely at the zero depth position. However, in the magnetic head, when the magnetic gap is cut out by the groove, the shape of the magnetic core on which the magnetic path is formed rapidly changes in the groove. For this reason, the magnetic flux generated in the magnetic core may leak in the groove, and the core efficiency may be reduced.

Therefore, the present invention develops the third method described above, and prevents leakage of magnetic flux in the groove by filling the groove serving as a depth marker with a good conductive material showing non-magnetism. It is another object of the present invention to provide a magnetic head in which a magnetic flux is concentrated on a magnetic gap to reduce an inductance, and a core efficiency per inductance is improved.

[0019]

In order to achieve the above-mentioned object, a magnetic head according to the present invention comprises a metal magnetic thin film formed obliquely on a substrate and a concave portion formed with a thin-film coil. The magnetic gap includes a pair of magnetic core halves each having a flat butted surface made of a non-magnetic material, and a magnetic gap formed by abutting the front butted surfaces of the metal magnetic thin film so as to face each other via the non-magnetic material. In the formed magnetic head, at least one of the pair of magnetic core halves has a groove for checking the depth of the magnetic gap, the front abutting surface being cut out, and the magnetic core half being cut off. Are formed substantially in parallel with the medium sliding surface so that both end portions thereof face each other, and the groove portion is filled with a non-magnetic good conductive material.

In the magnetic head according to the present invention constructed as described above, since the groove portion is filled with a non-conductive, high-conductivity material, the leakage of magnetic flux in the groove portion is prevented, and the magnetic gap is prevented. The magnetic flux concentrates on the wire, and the inductance decreases. Therefore, such a magnetic head has improved core efficiency per inductance.

[0021]

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 or the like. The pair of magnetic core halves 2 and 3 are made of MnO-
A non-magnetic substrate 4 made of a NiO-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 gap material G,
As shown in FIG. 2 (the thin film coil 7 is not shown in FIG. 2), the metal magnetic thin film 5 has a magnetic core 8.
To form When the magnetic recording medium slides in a direction indicated by an arrow A in FIG. 2, the magnetic core 8 reproduces the signal magnetic field recorded on the magnetic recording medium or transmits the signal magnetic field to the magnetic recording medium. Record and work.

In order to adjust the contact state of the magnetic head 1 with the magnetic recording medium, the sliding surface 9 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. In addition, the magnetic head 1 is provided with a contact width regulating groove 10 for adjusting the contact area with the magnetic recording medium. The contact width regulating grooves 10 are formed on both side surfaces of the magnetic head 1 in parallel with the sliding direction A of the magnetic recording medium.

In the magnetic head 1, the metal magnetic thin film 5 is formed of a material exhibiting soft magnetism such as sendust (Fe-Al-Si 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 gap material G, the magnetic core 8 slides on the magnetic recording medium as shown in FIG. It is arranged obliquely to the direction A.

The metal magnetic thin film 5 is configured so that its cross section has a substantially U-shape. In other words, the metal magnetic thin film 5 has the concave portion 5a at the substantially central portion of the end surface on the side where the magnetic core halves 2 and 3 are joined.

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 the front butting surface 11 and the rear butting surface 12 And has the following. The front butting surface 11 of one magnetic core half 2 and the front butting surface 11 of the other magnetic core half 3 are butted with a gap material G therebetween to form a front gap 13. The rear butting surface 12 of one magnetic core half 2 and the rear butting surface 12 of the other magnetic core half 3 are butted with a gap material G therebetween to form a back gap 14.

The metal magnetic thin film 5 has a bonding surface 2a,
3a, the thin film coil 7 having the rear abutting surface 12 substantially at the center.
Has a coil forming recess 15 formed therein. A coil connection terminal 16 is formed in the coil forming recess 15 near the rear butting surface 12. The thin-film coil 7 is formed in the coil-forming recess 15, and the end on the center side is connected to the coil connection terminal 16.

The coil connection terminals 16 are formed with their heights adjusted so as to form the same surfaces as the joint surfaces 2a, 3a of the pair of magnetic core halves 2, 3. In the magnetic head 1, when the pair of magnetic core halves 2 and 3 are joined, the pair of coil connection terminals 16 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 9 of the recording medium. External connection terminals 17 are formed on the pair of magnetic core halves 2 and 3 on the side opposite to the sliding surface 9 of the recording medium.
The outer peripheral end of the thin-film coil 7 is connected to the external connection terminal 17.

The external connection terminals 17 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 17 are formed at positions where the heights of the pair of magnetic core halves 2 and 3 are different from each other so that a short circuit does not occur when the pair of magnetic core halves 2 and 3 are joined. Have been.

Incidentally, in the magnetic head 1, FIG.
The depth B, which is the depth of the front gap 13 from the sliding surface 9 as shown in FIG. In the magnetic head 1, a groove 18 is formed as a depth marker for determining the depth zero position 13a of the front gap 13 in order to read the depth B accurately and easily.

The groove portion 18 is formed by cutting out the front butting surfaces 11 of the pair of magnetic core halves 2 and 3, and both ends thereof are substantially parallel to the sliding surface 9 as desired on both side surfaces of the magnetic head 1. Is formed. The groove 18 is provided with a pair of magnetic core halves 2 and 3.
, Each has a circular cross section when the pair of magnetic core halves 2 and 3 are joined and integrated.

The groove 18 is filled with a non-magnetic good conductive material 19 such as Cu.

In the magnetic head 1, since the magnetic core 8 is cut off by the groove 18, the shape of the magnetic core 8 changes rapidly at the position of the groove 18. Therefore, in the magnetic head 1, when the groove 18 is not filled with the good conductive material 19, the magnetic flux generated inside the magnetic core 8 leaks in the groove 18 as shown by an arrow C in FIG. Would.

However, in the magnetic head 1,
Since the groove 18 is filled with the good conductive material 19, the leakage of the magnetic flux in the groove 18 is prevented as shown by an arrow D in FIG. The magnetic head 1
In this case, the magnetic flux generated in the magnetic core 8 flows intensively in the front gap 13 because the leakage in the groove 18 is prevented. Therefore, the magnetic head 1
Means that the inductance of the magnetic core 8 is reduced.

Accordingly, in the magnetic head 1, the core efficiency per inductance is improved by filling the groove portion 18 with the good conductive material 19.

Further, in the magnetic head 1, the depth B of the front gap 13 may be worn out due to wear or the like when the head is used, and the groove 18 may be exposed on the sliding surface 9.
At this time, if the groove 18 remains in the gap, the sharp edge of the groove 18 is formed on the sliding surface 9 of the magnetic head 1, and the magnetic recording medium sliding on the sliding surface 9 is damaged. There is a fear.

However, in the magnetic head 1,
Since the groove 18 is filled with the good conductive material 19, even when the depth B of the front gap 13 is worn, the edge of the groove 18 is not formed on the sliding surface 9 and the magnetic recording medium is damaged. Is prevented.

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 is formed such that the inclined surface 4a is formed obliquely at a predetermined angle, but the inclined surface 4a is formed, for example, in 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 Sendust (Fe-Al-Si alloy), but the present invention is not limited to such a structure. Absent. The metal magnetic thin film 5 is made of, for example, Fe-Ta-N alloy, Fe-Al alloy, Fe-Si
-Co alloy, Fe-Ga-Si alloy, Fe-Ga-Si
-Ru alloy, Fe-Al-Ge alloy, Fe-Ga-Ge
Alloy, Fe-Si-Ge alloy, Fe-Co-Si-Al
An alloy or a crystalline alloy such as an Fe—Ni alloy may be used. Alternatively, the metal magnetic thin film 5 is made of Fe, Co,
An alloy composed of one or more elements of Ni and one or more elements of P, C, B, Si, or
1, Ge, Be, Sn, In, Mo, W, Ti, Mn,
Metal-metalloid amorphous alloys typified by alloys containing 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 f 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 formed of a single-layer metal magnetic thin film, but it is preferable that the non-magnetic thin film layer and the magnetic thin film layer are alternately laminated. Thus, the magnetic head 1 can have high sensitivity in a higher frequency range.

Further, in the magnetic head 1, the groove 18 is formed in each of the pair of magnetic core halves 2 and 3, but the configuration is not limited to this. Groove 18
May be formed on at least one of the pair of magnetic core halves 2 and 3. In the present embodiment, the groove 18 is filled with Cu as a good conductive material 19 by electrolytic plating. The good conductive material 19 filled in the groove 18 is not limited to Cu, but may be any good conductive material showing non-magnetism, for example, Au or the like. Further, the good conductive material 19 to be filled in the groove portion 18 may be filled by, for example, sputtering instead of using electrolytic plating.

Further, the groove 18 is formed so as to cut off the front butting surface 11 in the pair of magnetic core halves 2 and 3. In particular, the groove 18 is opposite to the sliding surface 9 of the front butting surface 11. It is preferable that the side end is formed so as to be cut out. As a result, as shown in FIG. 3, the side edge 18 a of the groove 18 on the side of the sliding surface 9 always matches the zero depth position 18 a of the front gap 13. That is, in the magnetic head 1, the distance from the sliding surface 9 to the side edge 18a is the depth B.

Therefore, in the magnetic head 1, the depth B of the front gap 13 can be adjusted with high precision by polishing the sliding surface 9 while checking the distance from the sliding surface 9 to the side edge 18a of the groove 18 from the side. Can be adjusted.

For this reason, in the magnetic head 1, by polishing the sliding surface 9 so that the depth B of the front gap 13 is reduced, it is possible to improve the head efficiency and obtain a large recording / reproducing output. it can.

In the present embodiment, the cross section of the groove 18 formed in each of the pair of magnetic core halves 2 and 3 has a semicircular shape, but may have a polygonal shape, for example.

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 13. When the direction of the applied signal magnetic field changes, the direction of the magnetic flux flowing through the magnetic core 8 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
The magnetic core 8 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 13. 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.

First, to manufacture the magnetic head 1,
As shown in FIG. 5, 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.

The slope 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. 7, 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 the present embodiment, the metal magnetic thin film 27
Is, for example, 4 μm of Fe—Al—Si alloy (Sendust).
m and alumina of 0.15 μm are alternately laminated and three layers of Fe—Al—Si alloy layer are provided. When the metal magnetic thin film 27 is formed in a plurality of layers, alumina, SiO ₂ and Si
Materials such as O are used alone or in combination. 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 to separate the magnetic core 8 into a predetermined size, and a winding for forming a magnetic gap in each magnetic core 8 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 8 by magnetically separating the magnetic core 8 in the front-back direction on the substrate 21 and forming a closed magnetic path in each magnetic core 8. is there. Although two separation grooves 28 are formed in the example of FIG. 8, 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 so as to have a depth enough to completely cut the metal magnetic thin film 27 in order to magnetically separate the magnetic cores 8 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 by the magnetic core 8 having the front butting surface 11 and the rear butting surface 12.
In order to form the concave portion 15 for coil formation, 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 11 and the rear butting surface 12. Here, the width is about 140 μm, and And the length of the rear butting surface 12 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 11
The side surface was a 45-degree inclined surface 29a. This allows
The magnetic core 8 has a structure in which the magnetic flux is concentrated on the sliding surface 9, thereby improving the sensitivity.

Next, as shown in FIG. 9, 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.

The low-melting glass 30 has a viscosity coefficient of 10 ² at a heat temperature at which the metal magnetic thin film 27 exhibits good soft magnetic properties.
Is preferably those which are ~10 ⁶ Pa · s, still more preferably it is desirable at 10 ³ ~10 ⁵ Pa · s. Thus, the metal magnetic thin film 27 does not lose its soft magnetic properties when the substrate 21 is filled with the low-melting glass 30 dissolved therein.

Next, as shown in FIG. 10, the solidified low melting point glass 30 is subjected to a grinding process using a grindstone or the like to form a terminal groove 31. This terminal groove 31
It is formed so as to be located immediately above the above-described separation groove 28, and its 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 becomes the external connection terminal 17 in the magnetic head 1 described above.

Next, as shown in FIG. 11, the low-melting glass 30 is etched to form the coil-forming recess 15 and the groove 18, and the thin-film coil is formed in the coil-forming recess 15. 7 is formed as a thin film.

The coil forming recess 15 has a substantially rectangular shape with the rear abutting surface 12 substantially at the center thereof.
It is formed by performing an etching process on portions other than the terminal 2 and the coil connection terminal 16. The coil forming recess 15 has a groove 15a reaching the terminal groove 31 from one end thereof.

The groove 18 is located on the front butting surface 11 and is formed perpendicular to the longitudinal direction of the front butting surface 11. The groove 18 is formed so as to be substantially parallel to the sliding surface 9 and to face both side surfaces of the magnetic head 1 when the pair of magnetic core halves 2 and 3 are separated into the magnetic head 1. I do.

Thereafter, a thin film coil 7 is formed in the coil forming recess 15. The thin-film coil 7 has one end 7a disposed on the coil connection terminal 16 and the rear abutting surface 1.
It has a shape wound many times so as to draw a circle centered at 2. The thin-film coil 7 is drawn out into a groove 15 a formed at one end of the coil forming recess 15, and the other end 7 b is electrically connected to an external connection terminal 17 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 15.
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.

The groove 18 is filled with a good conductive material 19 which is non-magnetic. In the present embodiment,
As the good conductive material 19, Cu, which is the same material as the thin film coil 7, was used. Thereby, the good conductive material 19 can be formed in the same manner and at the same time as the formation of the thin-film coil 7 described above.

Therefore, in this embodiment, a new process is not required for filling the groove portion 18 with the good conductive material 19.

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 fill the coil forming recess 15 in which the above-mentioned 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 11 and the rear butting surface 12 which are exposed on one main surface of the substrate 21, but the portions covering these 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 .

In the present embodiment, the groove 18
Is formed by etching in the same manner as the coil-forming recess 15, but may be formed by machining using a slicer or the like, for example. Further, the groove 18 is formed to have a semicircular cross section, but may have a polygonal shape, for example.

The groove 18 is formed so as to cut off the front butting surface 11.
It is desirable that the end opposite to the sliding surface 9 be cut out. Accordingly, the groove 18 can be formed such that the position of the side edge 18 a on the sliding surface 9 side always matches the zero depth position 13 a of the front gap 13 in the magnetic head 1. That is, in the magnetic head 1, the distance from the sliding surface 9 to the side edge 18a is the depth B.

Further, the depth of the groove 18 toward the substrate 21 is preferably 2 to 15 μm, and more preferably 5 to 10 μm. Magnetic head 1
When the depth of the groove 18 is less than 2 μm, the groove 18
The core efficiency may be degraded as compared with a magnetic head in which one side edge 18a of the front head abutment surface 11 and the end opposite to the sliding surface 9 are aligned. When the depth of the groove 18 exceeds 15 μm, the magnetic core 8 is cut off by the groove 18 so that the one side edge 18 a of the groove 18 and the front abutting surface 11 are separated from each other. Core efficiency may be degraded as compared with a magnetic head in which the sliding surface 9 and the opposite end are aligned.

It is desirable that the good conductive material 19 be filled in the groove 18 with a thickness of 2.0 μm or more.
Thereby, the good conductive material 19 can reliably prevent the leakage of the magnetic flux in the groove 18 where the shape of the magnetic core 8 changes rapidly. The low-melting glass 30 filled in the substrate 21 is provided so that the good conductive material 19 does not hinder the pair of magnetic core halves 2 and 3 from abutting each other.
It is necessary to be formed with a thickness lower than one main surface.

Further, the thin film coil 7 and the good conductive material 1
In the previous stage of the process for forming the substrate 9, for example, Cu, A
A base such as u may be formed by sputtering or the like.
The underlayer is not limited to Cu and Au, and may be any material having good adhesion to the materials used for the thin film coil 7 and the good conductive material 19.

Further, in the present embodiment, the groove 1
8 was formed on the pair of magnetic core halves 2 and 3, respectively.
It is not limited to such a configuration. The groove 18 may be formed in at least one of the pair of magnetic core halves 2 and 3.

Further, in this embodiment, the grooves 18 are located on the respective front butting surfaces 11, and the pair of magnetic core halves 2 and 3 are joined and integrated to separate the individual magnetic heads 1. In this case, the magnetic head 1 is formed to have a length enough to reach the side surface, but may be formed by a single groove over a plurality of front butting surfaces 11, for example.

Next, as shown in FIG. 12, a side groove 32, which is a square groove, is formed so as to cross the front butting surface 11 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, for example, a depth of 50 μm and a width of 400 μm. When the side grooves 32 are formed, the side grooves 32
One end of the front abutment surface 11 is exposed on the side surface of. The side grooves 32 are formed to expose the upper end of the front butting surface 11 as a positioning index when the pair of magnetic core half blocks 33 are butted, as described later.

After the formation of the side grooves 32, the one main surface is mirror-finished by polishing the one main surface. At this time, the front butting surface 11 and the rear butting surface 12 covered with the protective film are exposed to the outside.

Next, as shown in FIG. 13, metal diffusion bonding is performed by accurately positioning the pair of magnetic core half blocks 33. At this time, the pair of magnetic core half blocks 33
Performs patterning of Au on the joint, and forms
The upper ends of the front butting surfaces 11 facing each other are opposed to each other so that accurate positioning is achieved.

As described above, by correctly opposing the upper ends of the front butting surfaces 11 facing the side grooves 32, the rear butting surfaces 12 and the coil connection terminals 16 can be accurately faced. Then, by applying a predetermined temperature and pressure to the pair of magnetic core half-blocks 33 butted against each other, metal diffusion bonding is performed to produce a magnetic head block 38.

In this embodiment, the metal diffusion bonding is performed by patterning Au.
The pair of magnetic core half blocks 33 may be joined using an adhesive, water glass, or the like.

Next, as shown in FIG. 14, the magnetic head block 38 is separated into individual magnetic heads 1.

At this time, first, the magnetic head block 38
Is cut in the longitudinal direction on the basis of the groove 18 as a depth marker in order to expose the surface serving as the sliding surface 9 on which the magnetic recording medium slides. Then, the magnetic head block 38 performs a cylindrical cutting process on the exposed surface so as to have a cylindrical shape. As a result, this surface becomes the sliding surface 9 of the magnetic head 1. After that, the contact width regulating groove 10 is ground on the magnetic head block 38. The contact width regulating grooves 10 are formed at portions corresponding to both side surfaces of the sliding surface 9 of each magnetic head 1 separated from the magnetic head block 38.

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

[0092]

As described above, in the magnetic head according to the present invention, the groove for confirming the depth of the magnetic gap is filled with a nonconductive good conductive material. Therefore, in the magnetic head, the leakage of the magnetic flux in the groove is prevented, and the magnetic flux is concentrated on the magnetic gap, so that the inductance is reduced. Therefore, such a magnetic head has improved core efficiency per inductance. As a result, the 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 side view of a main part showing a groove of the magnetic head.

FIG. 4 is a diagram for explaining a magnetic flux generated in a magnetic core of the magnetic head, in which (A) is a schematic diagram of a main part showing a case where a groove portion is not filled with a good conductive material, and (B). FIG. 4 is a schematic diagram of a main part showing a case where a groove portion is filled with a good conductive material.

FIG. 5 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. 6 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. 7 is a view for explaining the same method, and is a perspective view showing a substrate on which a metal magnetic thin film is formed.

FIG. 8 is a diagram for explaining the same method, and is a perspective view showing a substrate on which a second groove processing has been performed.

FIG. 9 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. 10 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. 11 is a view for explaining the same method, and is a perspective view of a main part showing a substrate on which a coil forming recess is formed.

FIG. 12 is a diagram for explaining the same method, and is a perspective view showing a magnetic core half block.

FIG. 13 is a view for explaining the same method, and is a perspective view showing a state where a pair of magnetic core half blocks are butted.

FIG. 14 is a diagram for explaining the same method, and is a perspective view showing a magnetic head block.

FIG. 15 is a diagram for explaining a method of measuring the depth of a magnetic gap in a conventional MIG type magnetic head;
(A) is a main part plan view showing a state where the depth of the magnetic gap is measured, and (B) is an enlarged view of the magnetic gap part confirmed by a microscope.

FIG. 16 is a diagram for explaining a method of measuring the depth of a magnetic gap in a conventional bulk thin-film magnetic head;
(A) is a main part plan view showing a state where the depth of the magnetic gap is measured, and (B) is an enlarged view of the magnetic gap part confirmed by a microscope.

FIG. 17 is a diagram for explaining a method of measuring the depth of a magnetic gap in a conventional bulk thin-film magnetic head;
FIG. 2A is a plan view of a main part of a bulk thin film magnetic head,
(B) is a sectional view taken along line II in (A).

[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 magnetic core, 9 sliding surface, 10 contact width regulating groove, 11 front butting surface, 12 rear butting surface, 13 front gap, 14 back gap,
15 Coil forming recess, 17 External connection terminal, 18
Groove, 18a Side edge (on the sliding surface side of the groove), 19 Good conductive material, G gap material

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuka Kadoma 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Koji Suzuki 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F term (reference) 5D093 AA01 AC01 BA12 BB04 CA01 5D111 AA02 AA13 BB12 CC07 CC23 GG03 KK04 KK05

Claims (4)

[Claims] 1. A pair of magnetic core halves having 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 flattened by a nonmagnetic material. A magnetic head in which a magnetic gap is formed by abutting the front butting surfaces of the metal magnetic thin films so as to face each other with a non-magnetic material interposed therebetween, wherein at least one of the pair of magnetic core halves has ,
A groove for confirming the depth of the magnetic gap cuts out the front abutting surface, and is substantially parallel to the medium sliding surface so that both ends face both sides of the magnetic core half. A magnetic head formed, wherein the groove is filled with a good conductive material showing non-magnetism. 2. The magnetic head according to claim 1, wherein the groove is formed so as to cut off an end of the front abutting surface opposite to the medium sliding surface. 3. The magnetic head according to claim 1, wherein the depth of the groove is 2 to 15 μm. 4. The magnetic head according to claim 1, wherein the good conductive material is filled in the groove with a thickness of 2.0 μm or more.