JPH1040513A - Magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To visually identify the position of a magnetic gap of a magnetic head. SOLUTION: On a non-magnetic substrate 5, a magnetic head 1 is composed of a metal magnetic layer 5 forming a magnetic core, and a thin film coil 7 winding the magnetic head 5. A pair of magnetic head halves filled with glass 6 is joined, at least, on a part of the metal magnetic layer 5 through a gap material 3 made of non-magnetic material. The gap material 3 is made of a material visually different from the metal magnetic layer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head mounted on a magnetic recording / reproducing apparatus such as a video cassette recorder, and more particularly to a novel magnetic head capable of easily and visually identifying the position of a magnetic gap.

[0002]

2. Description of the Related Art A magnetic head must exhibit good electromagnetic conversion characteristics in a higher frequency band in order to cope with a higher density of a magnetic recording medium and digitization of an information signal. Requested.

Heretofore, as a magnetic head used in a video cassette recorder or the like, a magnetic head formed of a magnetic core formed of ferrite and having a metal magnetic film formed on a magnetic gap forming surface thereof has been proposed.
A G (metal-in-gap) type magnetic head, a laminated magnetic head in which a metal magnetic layer is sandwiched between nonmagnetic ceramic substrates, and the like have been put to practical use.

However, the MIG type magnetic head has a large impedance and is not suitable for use in a high frequency band. On the other hand, in the stacked magnetic head, it is necessary to reduce the thickness dimension of the metal magnetic layer constituting the magnetic path with the reduction of the track width due to the high-density recording. I will.

Therefore, as a magnetic head having high reproduction efficiency in a high frequency band, a metal magnetic layer functioning as a magnetic core is formed on a part of a non-magnetic substrate so as to shorten a magnetic path. There has been proposed a magnetic head of a type in which a thin film coil is formed on a magnetic gap forming surface by a thin film forming process so as to wind.

[0006] This magnetic head is formed by joining a pair of magnetic head halves each having a metal magnetic layer serving as a magnetic core and a thin film coil formed on a substrate. In this magnetic head half, a coil connection terminal located at the center of the thin film coil of one magnetic head half and a coil connection terminal located at the center of the thin film coil of the other magnetic head half have a pair of magnetic head halves. Connected by joining the bodies. In this magnetic head, the metal magnetic layer of one half of the magnetic head and the metal magnetic layer of the other half of the magnetic head abut against each other, and a front gap and a back gap are formed at the abutted portion. Is done.

In the magnetic head constructed as described above, a metal such as Au is formed in the front gap portion, the back gap portion and the coil connection portion of each magnetic head half, and this Au is subjected to low-temperature metal diffusion bonding. By
A pair of magnetic head halves are integrated.

[0008]

SUMMARY OF THE INVENTION
When mounting on a recording / reproducing drum used in a video cassette recorder or the like, it is required to arrange a magnetic gap at a predetermined position on the drum with high precision. Therefore, this magnetic head is required to be able to easily identify the position of the magnetic gap.

However, in the above-described magnetic head, since the magnetic core and the magnetic gap are formed of metal, the appearance of the magnetic core and the magnetic gap are similar, and the position of the magnetic gap on the medium sliding surface can be visually determined. Difficult to identify. For this reason, this magnetic head has a problem that the alignment accuracy of the magnetic gap is greatly deteriorated in the head mounting step in the drum manufacturing step, and the manufacturing yield of the drum is reduced.

Accordingly, the present invention has been proposed in view of the above situation, and has as its object to provide a magnetic head which facilitates discrimination between a metal magnetic layer serving as a magnetic core and a magnetic gap.

[0011]

A magnetic head according to the present invention for solving the above-mentioned problems has a metal magnetic layer serving as a magnetic core and a thin-film coil wound around the metal magnetic layer formed on a non-magnetic substrate. In addition, a pair of magnetic head halves at least partially filled with glass on the metal magnetic layer is a magnetic head that is joined via a gap material made of a non-magnetic material, wherein the gap material is The metal magnetic layer is made of a material having a different appearance from that of the metal magnetic layer, and the gap material and the metal magnetic layer are visually distinguishable.

In the magnetic head thus configured, the appearances of the metal magnetic layer and the gap material are different, and the metal magnetic layer and the gap material can be visually distinguished.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a magnetic head according to the present invention will be specifically described below with reference to the drawings.

A magnetic head 1 according to the present embodiment is a magnetic head used for a video tape recorder, a video cassette recorder, and the like. As shown in FIGS.
A pair of magnetic head halves 2a and 2b are abutted through a magnetic gap g and joined and integrated.

The magnetic head halves 2a and 2b are composed of a non-magnetic substrate 4, a metal magnetic layer 5 formed on the non-magnetic substrate 4 and functioning as a magnetic core, a non-magnetic substrate 4 and a metal magnetic layer. 5, a glass 6 filled on a glass 5 and a thin film coil 7 formed on the glass 6 by a thin film forming process. Then, a pair of magnetic head halves 2a, 2a
b is joined such that the respective metal magnetic layers 5 abut each other to form a front gap fg and a back gap bg between the respective metal magnetic layers 5. Also,
The pair of magnetic head halves 2a and 2b are provided with terminal portions 8a and 8b of the thin-film coil 7 formed on the glass portion.

The front gap fg is formed of the gap material 3 having an appearance different from that of the metal magnetic layer 5 so that the front gap fg can be easily visually distinguished from the metal magnetic layer 5.

In the magnetic head 1 configured as described above,
The front gap fg is formed by the gap material 3 having a different appearance from the metal magnetic layer 5. That is, the metal magnetic layer 5 formed as a magnetic core and the gap material 3 have different visual appearances. Therefore, in the magnetic head 1, the position of the magnetic gap g can be identified. .

Hereinafter, the magnetic head 1 will be described in detail through a method of manufacturing the same.

In manufacturing the magnetic head 1, first, as shown in FIG. 3, a non-magnetic substrate 4 of MnO--NiO or the like is prepared.

Next, as shown in FIG. 4, a plurality of magnetic core grooves 4a are formed on the non-magnetic substrate 4 to form an inclined surface on which a magnetic core is formed, that is, a magnetic core forming surface. 4a are formed in parallel and at equal intervals so that one of the surfaces 4a becomes an inclined surface. For example, several tens of the magnetic core grooves 4a are formed using a grinding wheel having one surface formed at about 45 degrees so that the inclination of the inclined surface is about 45 degrees. The inclination of the inclined surface is preferably about 25 to 60 degrees, but is more preferably about 35 to 50 degrees in consideration of the pseudo gap and track width accuracy.

Next, as shown in FIG. 5, a metal magnetic layer 5 is formed on the nonmagnetic substrate 4 on which the inclined surface is formed. The metal magnetic layer 5 has a metal magnetic film made of sendust (Fe-Al-Si alloy) having a thickness of about 5 μm and an insulating film made of Al ₂ O ₃ having a thickness of about 0.15 μm alternately. Are laminated in three layers.

Here, since the metal magnetic layer 5 is mainly made of a metal magnetic material, it has a so-called metallic luster appearance.

The structure of the metal magnetic layer 5 may be a single metal magnetic film. However, in order to reduce eddy current loss and to provide high sensitivity in a high frequency band, the metal magnetic layer 5 is formed of an insulating film as described above. Is preferably divided into a plurality of layers. At this time, the thickness of the insulating film needs to be at least a thickness at which an insulating effect can be obtained, but if it is too thick, it acts as a pseudo gap, so it is necessary to make it thin.

As a method for forming the metal magnetic layer 5, a sputtering method is preferable.
A physical film forming method other than the sputtering method such as BE), a chemical film forming method, or the like may be used.

As a material of the metal magnetic film, Sendust is preferable, but other metal magnetic materials, for example,
Alloys similar to Sendust, nitrided soft magnetic alloys, carbonized soft magnetic alloys, and the like can also be used. As the material of the gap material 3, Al ₂ O ₃ , SiO ₂ and SiO can also be used, and a mixture of these Al ₂ O ₃ , SiO ₂ and SiO can also be used.

Next, as shown in FIG. 6, a winding groove 4b for forming a thin film coil 7 is formed on the substrate 4 on which the metal magnetic layer 5 is formed, at right angles to the magnetic core groove 4a.
And a separation groove 4c for separating the metal magnetic layer 5 for each magnetic core.

As shown in FIG. 2, the winding groove 4b is formed, for example, so that the metal magnetic layer 5 on the front gap fg side is obliquely narrowed down toward the front gap fg. The front gap fg side is formed by a grindstone having a slope of about 45. As described above, when the metal magnetic layer 5 on the front gap fg side is narrowed toward the front gap fg, the magnetic flux is concentrated and high recording sensitivity is obtained.

However, if the shape of the winding groove 4b is such that the metal magnetic layer 5 on the front gap fg side is narrowed down toward the front gap fg, the slope of the winding groove 4b on the front gap fg side is formed. The angle need not be 45 degrees. Further, the shape of the winding groove 4b on the front gap fg side may be an arc or a polygon.

The depth of the winding groove 4b depends on the metal magnetic layer 5
However, if it is too deep, the magnetic path length increases and the magnetic flux transmission efficiency decreases. Therefore, in the present embodiment, the winding groove 4b is formed so as to be slightly deeper than the thickness of the thin film coil 7 formed in a later step. The width of the winding groove 4b is determined by the width and the number of windings of the thin film coil 7 formed in a later step. In the present embodiment, the width of the winding groove 4b is about 140
μm.

On the other hand, the separation groove 4c may have any shape as long as the metal magnetic layer 5 is divided, and for example, has a rectangular shape which is easy to process. The depth of the separation groove 4c may be such that the metal magnetic layer 5 is completely separated. Further, the width of the separation groove 4c defines the length of the front gap fg, which is the front gap side portion of the metal magnetic layer 5, and the length of the back gap bg, which is the back gap side portion of the metal magnetic layer 5, and is desired. Front gap f of magnetic head 1
It is determined by a balance between the length of g and the length of the back gap bg. First, the length of the front gap fg is
Finally, in order to wrap the medium sliding surface when the magnetic head 1 is processed into a predetermined shape, the front gap fg is set to be longer than the finally desired front gap fg. The length of the back gap bg is set to a length at which the efficiency of the magnetic head 1 is sufficiently obtained. The width of the separation groove is determined based on these. Thus, a separation groove 4c is formed. Therefore, in the present embodiment, the length of the front gap fg is about 300 μm, and the length of the back gap bg is about 85 μm
The separation groove 4c is formed such that

Next, as shown in FIG.
a, the winding groove 4b and the separation groove 4c are melt-filled with glass 6 having a low melting point, and then the surface of the glass 6 is subjected to mirror finishing.

Next, as shown in FIG. 8, a terminal groove 9 is formed in the separation groove 4c filled with the glass 6. The depth and width of the terminal groove 9 may be arbitrary.

Next, as shown in FIG. 9, after filling the terminal groove 9 with a highly conductive material such as Cu by plating or the like,
The surface is smoothed again. The highly conductive material formed in the terminal groove 9 becomes the terminal portions 8a and 8b of the thin film coil formed in a later step.

Next, FIG.
As shown in (1), a spiral thin film coil 7 is formed for each magnetic core in the glass 6 so as to pass through the winding groove 4b. Here, the thin-film coil 7 is formed such that the end on the outer peripheral side reaches the terminal groove 9.

Next, after a portion other than the front gap fg and the back gap bg formed by the metal magnetic layer 5 is covered with a mask, the gap material 3 is formed by a sputtering method or the like. Since portions other than the front gap fg and the back gap bg are covered with the mask, the gap material 3 is formed only in the front gap fg and the back gap bg. In this embodiment, SiO ₂ is formed as the gap material 3 to a thickness of about 10 nm by a sputtering method.

The gap material 3 has a different appearance from that of the metal magnetic material 5 and may be made of a material capable of visually distinguishing the gap material 3 from the metal magnetic layer 5. Insulation materials are widely available. Specifically, SiO, SiO ₂ , Ta ₂ O ₅ , Al ₂ O ₃ , Cr ₂ O
₃ , a thin film made of an oxide insulating material such as ZrO ₂ , a laminated film thereof, and the like are preferable.

Next, the front gap fg and the back gap bg are covered with a mask, and a metal film is formed on a portion other than the front gap fg and the back gap bg by a sputtering method to join a pair of magnetic cores. Front gap fg and back gap bg
It is formed with the same thickness as the gap material 3 formed thereon. At this time, no metal film is formed on the front gap fg and the back gap bg because they are covered with the mask. This metal film is for bonding a pair of magnetic cores by low-temperature metal diffusion bonding. The metal film needs to be a material capable of low-temperature metal diffusion bonding at a temperature lower than the melting point of the glass 6, and Au, Ag, P
Noble metals such as t and Pd are preferred. In this embodiment mode, Au is formed to a thickness of about 10 n by a sputtering method.
m.

As described above, the magnetic gap g has the front gap fg and the back gap bg formed of the metal material 5 functioning as a magnetic core and the gap material 3 which can be easily visually identified. Therefore, the magnetic head 1 can perform high-precision and accurate positioning of the magnetic head even in a process of being mounted on a drum for a video tape recorder or a cassette tape recorder, for example. Therefore, it is possible to improve the yield in the drum manufacturing process.

Next, as shown in FIG. 11, the non-magnetic substrate 4 on which the magnetic core, the thin film coil 7 and the like are formed is cut in a row for each magnetic core in parallel with the terminal groove 9 to form a pair of magnetic cores. It is a head half block. Thereafter, the pair of magnetic head half blocks manufactured as described above are abutted so that the respective metal magnetic layers 5 face each other, and then are subjected to low-temperature metal diffusion bonding.

Finally, the magnetic cores are cut one by one, and then processed into a predetermined shape to join the pair of magnetic head halves 2a and 2b as shown in FIG. Is manufactured.

[0041]

As described above in detail, the magnetic head according to the present invention uses a material having a different appearance from the metal magnetic layer serving as the magnetic core as the gap material for forming the magnetic gap. And the metal magnetic layer can be easily distinguished visually.

In the magnetic head thus configured, since the gap material is made of a material having a different appearance from that of the metal magnetic layer, the gap material and the metal magnetic layer can be easily distinguished visually. The magnetic gap position can be easily and accurately recognized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration example of a magnetic head according to the present invention.

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

FIG. 3 is a perspective view showing a substrate.

FIG. 4 is a perspective view showing a state where a magnetic core groove is formed in a substrate.

FIG. 5 is a perspective view showing a state where a magnetic layer is formed on a substrate.

FIG. 6 is a perspective view showing a state in which a winding groove and a separation groove are formed on a substrate.

FIG. 7 is a perspective view showing a state where glass is filled on a substrate.

FIG. 8 is a perspective view showing a state where a terminal groove is formed on glass.

FIG. 9 is a perspective view showing a state where a conductor is formed in a terminal groove.

FIG. 10 is a perspective view showing a state where a thin film coil is formed.

FIG. 11 is a perspective view showing an example of how the substrate is cut for each magnetic core and the magnetic head half blocks are joined.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 magnetic head, 2 magnetic head halves, 3 gap material, 4 non-magnetic substrate, 5 metal magnetic layer, 6 glass, 7
Thin film coil

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Teruichi Inuma 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (4)

[Claims] A metal magnetic layer serving as a magnetic core and a thin-film coil wound around the metal magnetic layer are formed on a non-magnetic substrate, and at least a part of the metal magnetic layer is filled with glass. A magnetic head comprising a pair of magnetic head halves joined together via a gap material made of a non-magnetic material, wherein the gap material is made of a material having a different appearance from the metal magnetic layer, A magnetic head characterized in that it can be visually distinguished from a magnetic layer. 2. The magnetic head according to claim 1, wherein the gap material is made of an insulating material. 3. The magnetic head according to claim 1, wherein the gap material is made of an oxide insulating material. 4. A thin film coil formed on one half of the magnetic head and a thin film coil formed on the other half of the magnetic head are connected via a conductor arranged between the pair of magnetic head halves. The magnetic head according to claim 1, wherein the magnetic head is connected.