JPS62159306A - Magnetic head - Google Patents

Abstract

PURPOSE:To accurately detect the depth length of a magnetic gap, by providing grooves for winding in half bodies of a magnetic core and covering the surface of the half bodies in the vicinity of the front gap of the grooves with thin films of a ferromagnetic metal. CONSTITUTION:Magnetic core half bodies 21 and 22 are constituted in such a way that the sections of each core half body 11 and 12 from their surfaces to be brought into contact with each other to their grooves 17 and 18 for winding are respectively continuously covered with thin films of ferromagnetic metals 13 and 14. Then a magnetic gap (g) is constituted by putting the thin films 13 and 14 formed on the contacting surfaces of the magnetic core half bodies 21 and 22 together. The front gap side of the winding grooves 17 and 18 is cut so that slopes 17a and 18a of prescribed inclinations can be formed. Therefore, when the thin films 13 and 14 of the ferromagnetic metal coating the slopes 17a and 18a are joined with a gap spacer between them, the magnetic gap (g) is formed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic head, and in particular, a high frequency compatible magnetic head made of a composite magnetic material of a ferromagnetic oxide material and a ferromagnetic metal material. This relates to magnetic heads.

[Summary of the invention]

A magnetic head in which a magnetic core half is constituted by a magnetic core made of a ferromagnetic oxide and a ferromagnetic metal thin film adhered to the magnetic core, and the ferromagnetic metal yt films are butted against each other to form a magnetic gap. In this method, a winding groove is formed in the magnetic core half, and a ferromagnetic metal thin film is coated on at least the vicinity of the front gap of the winding groove, so that the depth length of the magnetic gap can be accurately detected. This is what I did.

[Conventional technology]

In the field of magnetic recording, the recording density and frequency of information signals are increasing, and in response to this, magnetic powders such as Fe and Co are being used as magnetic recording media.

So-called metal tapes, which use powdered ferromagnetic metals such as Ni, and so-called vapor-deposited tapes, in which ferromagnetic metal materials are deposited directly onto a base film using vacuum thin film formation techniques such as vapor deposition, have come into use. There is.

Since this type of magnetic recording medium has a high coercive force, the head material of the magnetic recording medium used for recording and reproduction is required to have a high saturation magnetic flux density. The ferrite material used has a low saturation magnetic flux density and cannot cope with the above-mentioned increase in coercive force.

Therefore, conventionally, in order to correspond to the above-mentioned high coercive force magnetic recording medium, the magnetic core part is made of an oxide magnetic material such as ferrite, and each of these magnetic core parts is made of a ferromagnetic metal as the main core part.
giIl! A so-called composite magnetic head has been proposed in which a magnetic gap is formed by abutting these ferromagnetic metal thin films.

[Problem that the invention seeks to solve]

By the way, as mentioned above, with the trend toward higher recording densities and shorter wavelengths in magnetic recording media, there is a desire for further improvement in magnetic efficiency for magnetic heads.

Under such circumstances, it is being considered to improve the magnetic efficiency by, for example, shortening or reducing the depth of the magnetic gap. Usually, this depth length is set to about several tens of micrometers.

By the way, in a magnetic recording/reproducing device, since recording and reproduction are performed with the magnetic recording medium and the magnetic head in sliding contact, in order to ensure this sliding contact, the surface of the magnetic head that faces the magnetic recording medium is However, as the depth length becomes shorter and smaller, processing accuracy during this cylindrical polishing becomes a problem.

That is, a slight deviation in the end point of cylindrical polishing greatly affects the depth length, making it extremely difficult to secure a predetermined depth length. Furthermore, 1. Since there is an unavoidable problem that the depth length decreases as the magnetic head is used, it is necessary to accurately grasp the depth length from the viewpoint of serviceability.

Therefore, in this type of magnetic head, accurately detecting the depth length is an important issue.

Therefore, the present invention was proposed in view of the above-mentioned circumstances, and it not only has excellent electromagnetic conversion characteristics and productivity, but also can accurately detect the depth length of a magnetic gap, and has high reliability. An object of the present invention is to provide a magnetic head having the following characteristics.

[Means for solving problems]

In order to achieve this object, the proposed magnetic head of the present invention has a winding groove formed in a magnetic core half made of a ferromagnetic oxide, and a ferromagnetic metal thin film is formed at least in the vicinity of the front gap of the winding groove. At the same time as depositing the above @magnetic metal
This is characterized in that a magnetic gap is formed by abutting the a-films against each other.

[Effect]

Ferromagnetic metal f! at least in the vicinity of the front gap of the winding groove. 1n* and a magnetic gap is formed by butting these ferromagnetic metal thin films against each other.
The width of the magnetic gear knob increases as the surface that contacts the magnetic recording medium wears. Therefore, if the thickness of the ferromagnetic metal thin film is set to a predetermined value, the depth length of the magnetic gap can be accurately detected by measuring the width of the magnetic gap.

〔Example〕

An embodiment of a magnetic head to which the present invention is applied will be described below with reference to the drawings.

FIG. 1 is an external perspective view showing an example of a magnetic head to which the present invention is applied, and FIG. 2 is an enlarged cross-sectional view of a main part showing the surface in contact with a magnetic recording medium.

In this magnetic head, a magnetic core portion (11).

(12) is formed of a ferromagnetic oxide material, such as Mn-Zn ferrite, and near the abutting surface, track width regulating grooves (15) and (16) for regulating the track width form approximately circular arcs on both sides. It is cut out.

In these track width regulating grooves (15) and (16),
Non-magnetic materials (19) and (20) are melt-filled to prevent wear of the ferromagnetic metal thin films (13) and (14).

In addition, each of the magnetic core parts (11) and (12) has windings for supplying 1epsilon to the magnetic head or for extracting signals from the magnetic head. It (17), (1
8) is perforated.

Furthermore, from the contact surfaces of the magnetic core portions (11) and (12) to the winding grooves (17) and (1B),
Thin ferromagnetic metals M (13) and (14) are successively deposited to form magnetic core halves (21) and (22). A magnetic gap g is formed by abutting the ferromagnetic metal thin films (13) and (14) formed on the contact surfaces of the magnetic core halves (21) and (22). .

Here, the front gap sides of the winding grooves (17) and (18) have slopes (17a) with a predetermined angle,
(18a) and thus deposited on the slopes (17a) and (18a).

A magnetic gap g is constructed by joining (14) via a gap spacer. Also,
The magnetic recording medium facing surfaces (21a) of the magnetic core halves (21), (22) are arranged so that the magnetic gap g is formed only by the ferromagnetic thin metal 111 (13), (14).
), (22a) is the above ferromagnetic metal IN (13)
, (14) are cylindrically polished until one end surface (13a), (14a) is exposed.

The inclination angle θ of the above-mentioned inclined surfaces (17a) and (18a) is
It is preferable to set it within the range of 10° to 80". If this angle θ is set to less than lO", the ferromagnetic metal thin film (
13) The film thickness of (14) becomes thinner, making it impossible to handle magnetic recording media with high coercive force that corresponds to high-density recording.On the other hand, if the above angle θ is set to 80'' or more, the film thickness near the magnetic gap g becomes thinner. The capacity of the magnetic core parts (11) and (12) (ferromagnetic oxide) is insufficient, and sufficient reproduction output cannot be obtained.More preferably, the angle θ is set in the range of 30'' to 60''. It's good.

In addition, ferromagnetic metal thin l1l (13), (14) is a ferromagnetic amorphous metal alloy, so-called amorphous alloy (for example, one or more elements of Fe, Ni, Co and P, C, B
.

An alloy consisting of one or more elements of St, or AJ, Ge, Be, Sn, ln with this as the main component.

Mecklum metalloid-based amorphous alloys such as alloys containing Mo, W, Ti, Mn, Cr, Zr, Hr, Nb, etc.;
or metal-metal amorphous alloys whose main components are transition elements such as Co, Hr, and Zr, rare earth elements, etc.)
, F6-A I S l alloy, Fe-Al alloy, Fe-3i-Go alloy, Fe-Ni alloy, and other ferromagnetic metal materials can be used. vacuum iff! method, sputtering method, ion blating method, cluster ion beam method, etc. Forming technology is employed. This ferromagnetic metal thin film (
11).

(12) is formed of a single layer in this embodiment, but for example, S fox, Tames, Alto3. Z ro
A plurality of layers may be formed via a highly wear-resistant insulating film such as z+5i20a. In this case, the number of laminated ferromagnetic metal thin films can be set arbitrarily.

In the magnetic head configured in this way, the depth length Dp can be detected accurately. Therefore, the processing accuracy of the polishing process for setting the depth length Dp is greatly improved, resulting in a magnetic head with excellent reliability.

Hereinafter, the method for detecting the depth length Dp will be described in detail with reference to FIG.

First, magnetic recording medium contact surfaces (21a) and (22a)
After measuring the radius of one end surface (13a), (14a) of the ferromagnetic metal fi films (13), (14) exposed to the surface, the depth length Dp is calculated by the following method.

That is, the length M in the depth direction in the magnetic gap g of the ferromagnetic metal thin films (13) and (14) is determined by the thickness of the ferromagnetic metal thin films (13) and (14) and the winding groove ( 17), sloped surface (17a) of (1B)
, can be easily determined from the inclination angle of (18a),
Also a magnetic core half (21).

(22) Since it can be measured before the butt, the length M in the depth direction is determined in advance.
, (22a) exposed ferromagnetic metal thin film (13)
, ferromagnetic metal thin film (13) so that the width of one end surface (13a), (14a) of (14) is completely zero,
This is the depth length when the cylinder is polished until it matches the edge of (14).

Therefore, it can be said that the larger the above width, the smaller the depth length, and the above volume! '! 1I (17), (1B)
When the inclination angles of the inclined surfaces (17a) and (18a) are θ, the depth length 1) p is expressed by the above-mentioned length M1 width and angle θ (expressed by equation 11).

From this formula (1), the above slope (17a), (18
a) If the film thicknesses of the ferromagnetic metal thin films (13) and (14) above are constant, the cylinder of the ferromagnetic gold recording medium facing surface (23) exposed to the magnetic recording medium facing surface (23) The depth length Dp can be easily controlled in the polishing process. Therefore, a highly reliable magnetic head is obtained.

Further, according to the magnetic head of this embodiment, a wide trunk can be formed even if the ferromagnetic metal thin films (13) and (14) are thin, which is advantageous in terms of productivity.

Next, in order to make the above-described embodiment more clear, a method of manufacturing the same will be explained with reference to FIGS. 4 to 8.

゛ To manufacture the magnetic head of the above example, first,
As shown in FIG. 4, on the upper surface (30a) corresponding to the joining surface when the magnetic core halves are brought together in a ferromagnetic oxide substrate (30) such as Mn-Zn ferrite, for example,
A winding groove (31) is formed over the entire width using a rotating grindstone or the like. The inclined surface (
31a) is the upper surface (
30a) at an angle of θ. The angle θ is within the range of 106 to 80@.

Next, as shown in FIG. 5, the ferromagnetic oxide group 1f
A ferromagnetic metal thin film (32) is deposited on the entire surface of i (30), that is, the upper surface (30a) including the winding groove (31), by a vacuum thin film forming technique such as sputtering.

Subsequently, as shown in FIG. 5, the ferromagnetic oxide substrate (
30) The top surface (30a) is surface ground and a ferromagnetic metal thin Il* is deposited on the top surface (30a) which is the butt surface.
(32) is removed, and the end face (32) forming the magnetic gap is removed.
a) is exposed so that the ferromagnetic metal thin film (32) remains only within the winding groove (31).

Furthermore, as shown in FIG. 6, the ferromagnetic oxide substrate (
30) On the upper surface (30a), a plurality of track width regulating grooves (33) having a substantially semicircular cross section are formed in parallel over the entire width of the substrate (30) so as to have a predetermined track width Tw using a rotary grindstone or the like. .

Next, the ferromagnetic oxide substrate (30) shown in FIG.
A gap spacer is attached to one of these substrates (30), (30), and as shown in FIG. ), (32) are joined and arranged so that they are butted against each other. And these substrates (30),
(30) is fused using a non-magnetic bonding material such as glass, and at the same time, is the track width restricted? Non-magnetic material (
34) Melt and fill (34). In addition, in this fusion step, filling of the track width regulating groove (31) with the non-magnetic material (34), (34) is performed on the substrate (
30) and (30), but for example, in the process shown in Figure 7, the track width regulating groove (33) is filled with a non-magnetic material in advance, and in the process shown in Figure 1O, only the glass is fused. Also good.

In addition, as the gap spacer, 5iOz, Zr
A 0z+TazOs+Cr film is used.

Afterwards, slicing is performed at the positions of the X-X line and the x'-x' line in Figure 8, and after cutting into a plurality of head chips, magnetic recording is performed to ensure sliding contact with the magnetic recording medium. The medium contacting surface is cylindrically polished to complete the magnetic head shown in FIGS. 1 and 2. The cylindrical polishing described above is performed until the ferromagnetic metal thin film (31) is exposed on the surface facing the magnetic recording medium, and at the end point, the width of the ferromagnetic metal thin film (31) exposed on the surface facing the magnetic recording medium is measured. You can decide by doing this. Therefore, the depth length can be easily controlled and a highly reliable magnetic head can be obtained.

In addition, in the slicing process, the substrate (30)
, (30) by making the slicing direction inclined with respect to the abutting surface, a magnetic head for azimuth recording can also be obtained.

The magnetic head includes the ferromagnetic metal thin films (3) and (4).
Since the track width can be increased regardless of the film thickness, the track width accuracy can be improved and the efficiency of this film forming process can be increased.

Here, the magnetic head shown in FIGS. 1 and 2! f
The core halves (11) and (12) have a ferromagnetic oxide substrate (20) as a base material, and a ferromagnetic metal thin film (13).
, (14) is a ferromagnetic metal thin film (31), a winding groove (17)
, (1B) correspond to the winding grooves (31), respectively.

Although specific examples of the present invention have been described above, the present invention is not limited to these examples.

For example, as shown in FIG. 9, the winding groove (17), (
18) Rather than forming a ferromagnetic metal thin film over the entire surface of the winding wire? It can also be applied to a magnetic head in which the ferromagnetic metal thin films (41), (42) are formed only on the inclined surfaces (17a), (18a) of lI, (17), (1B). Also in this case, the ferromagnetic metal thin film (41),
(42) magnetic recording medium facing surface (21a), (2
The depth length can be easily determined by measuring the width of one end surface (41a) and (42a) exposed in 2a). In the magnetic head shown in FIG. 10, the same members as those in the magnetic head shown in FIGS. 1 to 3 are given the same reference numerals, and detailed explanation thereof will be omitted.

To manufacture the above magnetic head, after manufacturing a magnetic core block as shown in FIG. 10, as in the previous example,
A track width regulating groove forming process, a bonding process of a pair of ferromagnetic oxide substrates, a slicing process, a second tube polishing process, etc. may be performed. The magnetic core block shown in FIG.
50a) and a slope (51a) that slopes at a predetermined angle.
A first groove (51) having a triangular cross section is cut, a thin ferromagnetic metal Jll (52) is coated, and a surface grinding process is performed (this may be done before surface grinding). A second groove (53) that together with the groove (51) forms a predetermined winding groove is cut out, and the ferromagnetic metal thin film (52) on the back gap side is cut out.
It is created by removing the .

〔Effect of the invention〕

As is clear from the above description, according to the magnetic head of the present invention, the depth length of the magnetic gap can be accurately detected by measuring the width of the exposed ferromagnetic metal thin film on the surface facing the magnetic recording medium. Therefore, the detection accuracy of the depth length is improved, and the depth length can be easily controlled during cylindrical polishing, resulting in high reliability.

Therefore, the magnetic head is suitable for use in a magnetic recording/reproducing device for high-density recording.

Furthermore, in the magnetic head of the present invention, although the magnetic gap is composed only of a ferromagnetic metal thin film with excellent magnetic properties, the track width of the magnetic gap can be freely set.
This magnetic head is highly practical not only in terms of electromagnetic conversion characteristics but also in terms of productivity.

[Brief explanation of drawings]

FIG. 1 is an external perspective view showing an embodiment of a magnetic head to which the present invention is applied, FIG. 2 is an enlarged plan view of the main part showing the surface in contact with a magnetic recording medium, and FIG. 3 is FIG. 2A-/ It is a schematic diagram which shows the cross-sectional state in l'ILIA. 4 to 8 are schematic perspective views showing the manufacturing process of the magnetic head shown in FIG. 1 according to the process order,
Figure 4 shows the winding groove forming process, Figure 5 shows the ferromagnetic metal thin film forming process, Figure 6 shows the surface grinding process, Figure 7 shows the track width regulating groove forming process, and Figure 8 shows the one-substrate bonding and slicing process. are shown respectively. FIG. 9 is an external perspective view showing another example of the present invention. 1st
The θ diagram is a schematic perspective view of a magnetic core block manufactured to manufacture the magnetic head shown in FIG. 9.

Claims (1)

[Scope of Claims] A winding groove is formed in a magnetic core half made of a ferromagnetic oxide, and a ferromagnetic metal thin film is coated at least in the vicinity of the front gap of the winding groove, and the ferromagnetic metal A magnetic head characterized by forming a magnetic gap by abutting thin films.