JPH01185811A - Magnetic head - Google Patents

Abstract

PURPOSE:To prevent the interface of a first metal magnetic film from acting as pseudo gap by forming said film so that at least such part of the abutted surfaces of a non-magnetic substrate as adjacent to the magnetic gap comes non-parallel with the magnetic gap plane. CONSTITUTION:The metal magnetic films 8, 9 are so formed that the non- parallel part of the abutting surfaces of the non-magnetic substrates 6, 7 come flat, and on top of the flat metal magnetic film, metal magnetic films 10, 11 are formed. As a result, the pseudo gap between this non-magnetic substrate and the metal magnetic film formed on the face-to-face surface can be prevented from occurring, the electromagnetic conversion characteristic and the reproduction output characteristic can be improved, further, the productivity of the magnetic head can be also improved.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a magnetic head used for recording and reproducing information on a high coercive force magnetic recording medium such as a so-called metal tape. This invention relates to an improvement in a magnetic head in which a magnetic field is formed.

[Summary of the invention]

In the present invention, a pair of magnetic core halves made of a non-magnetic substrate and a metal magnetic film formed along the abutting surfaces of the non-magnetic substrate are joined and integrated, and a closed magnetic path is configured by the metal magnetic film. In the magnetic head, a metal magnetic film is formed to flatten the non-parallel portions of the abutting surfaces of the non-magnetic substrate, and a metal magnetic film is further formed on the flattened metal magnetic film. The purpose is to prevent the generation of a gap between the non-magnetic substrate and the metal magnetic film formed on the abutting surface of the non-magnetic substrate, improve electromagnetic conversion characteristics and reproduction output characteristics, and improve productivity. The aim is to provide an excellent magnetic head.

[Conventional technology]

For example, in magnetic recording and reproducing devices such as VTRs (video tape recorders), information signals are being recorded at shorter wavelengths in order to improve image quality. High coercive force magnetic recording media, such as so-called metal tapes and vapor-deposited tapes in which a ferromagnetic metal material is directly deposited on a base film, have come into use.

On the other hand, research is being conducted in the field of magnetic heads to address this problem, and various magnetic heads using metal magnetic films in the magnetic core have been developed as magnetic heads suitable for high coercive force magnetic recording media.

As an example of such a magnetic head, one constructed as shown in FIG. 11, for example, is known.

As shown in FIG. 11, the magnetic head has two magnetic cores (1) that are made separately on the left and right sides with a magnetic gap G as the boundary.
, (It) pairs are butted and joined together. The above magnetic core halves (1) and (n) are connected to the substrates (1) and (2
) and metal magnetic films (3) and (4). At least one of the substrates (1) and (2) has a winding groove (2) for winding the coil.
5) is formed. Then, on the opposing surfaces of each substrate (1) and (2) formed parallel to the magnetic gap G,
Metal magnetic film from front side to back side (3)
, (4) are formed.

In this magnetic head, the metal magnetic films (3) and (4) having high saturation magnetic flux density in the vicinity of the magnetic gear G are formed of ferromagnetic metal thin films such as sendust or amorphous. The magnetic field strength is increased, making it suitable for high coercive force magnetic recording media such as metal tapes.

Here, the materials for the substrates (1) and (2) are as follows:
Examples include oxide magnetic materials such as ferrite, and non-magnetic materials such as ceramics.

When oxide magnetic materials such as ferrite are used for the substrates (1) and (2), metal magnetic films (3) and (4
) The substrates (1) and (2) and the metal magnetic film (
3), (4) interface K1. To! The ferrite is reduced to the interface Kl,! A diffusion layer is formed. This diffusion layer is nearly non-magnetic, and is located parallel to the original magnetic gap G, so it operates as a so-called pseudo-gap that causes undulations in frequency characteristics, causing deterioration of recorded and reproduced signals.

Therefore, in order to prevent the formation of the above-mentioned diffusion layer, it is desirable to use a non-magnetic material that cannot be reduced for the substrates (1) and (2).

Magnetic heads using the above-mentioned non-magnetic materials have advantages such as lower sliding noise than when using ferrite, and also because the inductance is reduced, making it possible to increase the number of turns of the coil and improving reproduction output. . Furthermore, since the metal magnetic films (3) and (4) constitute a closed magnetic path, the substrates (1) and (2) do not participate in the magnetic path, so there is no risk of forming a pseudo gap. etc.

Therefore, it is advantageous to use a non-magnetic material as the material for the substrates (1) and (2), and research on magnetic heads using substrates made of this non-magnetic material is progressing.

[Problem to be solved by the invention]

However, when recording and reproducing data was performed using a magnetic head fabricated using a nonmagnetic material on the substrates (1) and (2), so-called waviness, in which the frequency characteristics of the reproduced signal fluctuated periodically, was observed.

In the magnetic head, since the substrates (1) and (2) are made of a non-magnetic material, the substrates (1) and (2) are not reduced, but the substrates (1) and (2) are not reduced.
It is thought that because the opposing surface 2) is formed parallel to the magnetic gap G, a pseudo gap is generated due to the shape effect.

Therefore, the undulations of the reproduced signal cause fluctuations in the output signal,
This causes deterioration in image quality in video tape recorders and the like.

In order to prevent the formation of the pseudo gap described above, both sides of the opposing surface of the substrate are cut out diagonally so that the opposing surface of the substrate is not parallel to the magnetic gap G (i.e., when viewed from the recording medium sliding surface). The shape is approximately a letter .] Using a substrate, a pair of magnetic core halves with a metal magnetic film deposited on the re-stretched surface of the substrate are joined together via a hollow spacer, and formed on the double-ended slope. It is conceivable to use a magnetic head in which the track width is determined by abutting the diagonal films that have been formed.

However, with such magnetic heads, it is difficult to control the track width, and furthermore, it is difficult to process the facing surface of the substrate, which requires highly difficult work, which poses various problems in terms of yield and cost. left behind.

Therefore, the present invention was proposed to solve the above-mentioned problems by preventing the occurrence of a pseudo gap at the interface between the substrate and the metal magnetic film. It is an object of the present invention to provide a magnetic head that can improve magnetic conversion characteristics and recording/reproducing characteristics and has excellent productivity.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention includes a pair of magnetic core halves made of a non-magnetic substrate and a metal magnetic film formed along the abutting surfaces of the non-magnetic substrate, which are joined and integrated. In a magnetic head in which a closed magnetic path is constituted by a metal magnetic film, at least a portion of the abutting surfaces of the non-magnetic substrate near the magnetic gap has a non-parallel portion with the magnetic gap surface, and the metal magnetic film has a non-parallel portion with respect to the magnetic gap surface. It is characterized by comprising a first metal magnetic film that flattens the non-parallel portions of the abutting surfaces of the substrates, and a second metal magnetic film formed on the flat surface.

[Effect]

In the magnetic head of the present invention, at least the portion near the magnetic gap of the abutting surfaces of the nonmagnetic substrates is non-parallel to the magnetic gap surface, so that the abutting surface and the metal magnetic film formed on the abutting surface are There is no possibility that the film interface will act as a pseudo gap due to shape effects.

Further, a first metal magnetic film is formed on the abutting surface of the non-magnetic substrate having a non-parallel portion with respect to the magnetic gap surface to flatten the non-parallel portion of the non-magnetic substrate. Since the surface of the first metal magnetic film on which the second metal magnetic film is formed is flattened, the metal magnetic film generated when the metal magnetic film is simply formed on the abutting surface of the non-magnetic substrate is No deterioration of the magnetic properties of the film occurs.

Further, the interface between the first metal magnetic film and the second metal magnetic film formed on the flat surface of the first metal magnetic film acts as a pseudo gap because it becomes a bond between the metal thin films. There isn't.

〔Example〕

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

As shown in FIGS. 1 and 2, the magnetic head of this embodiment includes nonmagnetic substrates (6), (7), first metal magnetic films (8), (9), and second metal Magnetic film (1
0), (11) and a metal magnetic film having a two-layer structure as main components.
) is formed by conjugating the pairs.

Here, the magnetic gap g is the second metal magnetic film (1
0), (11) as a gap spacer (not shown). ] is formed by sandwiching and butting them together. The surface on which the magnetic gap g is formed serves as a magnetic gap surface. In this example, the track width Tw of the magnetic gap g is the non-magnetic substrate (6), (7).
The thickness of the non-magnetic substrate (6), (7
) is determined by the thickness of the

Therefore, metal magnetic films (8), (9), (10), (
11) Since the track width Tw can be increased regardless of the film thickness, it is possible to improve the accuracy of the track radius Tw and to improve the efficiency of this film forming process.

As the material constituting the above-mentioned non-magnetic groups Fi(6) and (7), a non-magnetic material made of ceramics or the like is used, for example. In addition, non-magnetic materials are not limited to ceramics, but include metal magnetic films (8), (9)
.

Any material can be used as long as the nonmagnetic substrates (6) and (7) are reduced during the heat treatment when forming the films (10) and (11), and a diffusion layer (so-called pseudo gap) is not formed. There is no harm in using it.

The abutting surfaces (12) of the non-magnetic substrates (6) and (7)
) and (13) are non-parallel portions so as not to have a plane parallel to the magnetic gap plane. That is,
The abutting surfaces (12) and (13) have uneven portions (14) and (15) in the direction of the track width 7w, and are formed so as not to have surfaces substantially parallel to the magnetic gap surface. has been done.

And the abutting surface (12) of one non-magnetic substrate (6)
The uneven portion (14) is formed from the front side to the back side. On the other hand, the other non-magnetic substrate (7) has a winding groove (16) for winding the coil.
) is formed, and the uneven portion (15) is formed on all surfaces except for the winding groove (16).

As a result, the formation of a pseudo-f gap that occurs due to the shape effect when the magnetic gap surface is parallel to the magnetic gap surface is prevented by utilizing so-called azimuth loss. Therefore, a magnetic head is realized that can provide good reproduction output without causing any waviness in the frequency characteristics.

In addition, in order to form the above-mentioned uneven parts (14) and (15),
For example, it may be formed by machining or etching. In addition, the uneven portion (14
), (15) may be formed at least on the abutting surfaces (12), (13) of the non-magnetic substrates (6), (7) in the vicinity of the magnetic gear lug g.

A metal magnetic film constituting a closed magnetic path is formed on each abutting surface (12), (13) of the non-magnetic substrates (6), (7).

The metal magnetic film has a two-layer structure of first metal magnetic films (8), (9) and second metal magnetic films (10), (11), and the structure is formed by the abutting surface. (12),
First metal magnetic films (8) and (9) are formed on (13), and a second metal magnetic film 11! J(10),
It is a laminated type in which (If) is formed into a film.

The first metal magnetic films (8), (9) have uneven portions (14), (
15), and further flatten the second metal magnetic film (10).
), the surface on which (11) is laminated is flattened.

As a result, the film properties of the first metal magnetic WJs (8) and (9) formed on the uneven portions (14) and (15) are not deteriorated, that is, the uneven portions (14)
, (15) If only a metal magnetic film is formed, the film characteristics deteriorate due to the influence of the film thickness distribution due to sputtering, etc., but this does not occur in this example.

The thickness of the first metal magnetic films (8) and (9) may be as long as it can flatten the uneven portions (14) and (15). There is no need to form a film.

On the other hand, since the second metal magnetic films (10) and (11) are formed along the flat surfaces of the flattened first metal magnetic films (8) and (9), they are uniform films. It is thick. Then, mainly this second metal magnetic film (10
).

(11) constitutes a closed magnetic path.

Further, the interface between the second metal magnetic film (10), (11) and the first gold magnetic film (8), (9) is approximately parallel to the magnetic gap g, but Since this is a bond between thin films, there is no risk of it operating as a pseudo gap.

Note that the metal magnetic films (8), (9), (10)
), (11), a ferromagnetic material having a high saturation magnetic flux density and excellent soft magnetic properties is used, but any conventionally known ferromagnetic material can be used. It doesn't matter whether it is crystalline or amorphous. To illustrate, F
e-Al-3i alloy, Fe-Aj! alloy, Fe-3
i-Co alloy, Fe-Ni alloy, Fe-AN-Ge
ferromagnetic metal materials such as Fe-Ga-Ge-based alloys, Fe-3i-Ge-based alloys, Fe-Co-3i-Af-based alloys, or Fe-Ga-3i-based alloys;
In order to further improve the corrosion resistance and wear resistance of the above Fe-Ga-3i alloy, the basic composition is Fe, Ga, Co (including those in which part of Fe is replaced with Co), and St. The alloy includes Ti, Cr, Mn, Zr, Nb, Mo, and Ta.

W, Ru, Os, Rh, Ir, Re, Ni, Pd.

It may also contain ferromagnetic amorphous metal alloys, so-called amorphous alloys (for example, Fe, Ni, etc.).

An alloy consisting of one or more elements of Co and one or more elements of P, C, B, and Si, or an alloy containing this as the main component and Al, G
e, Be, Sn, In, Mo, W.

Metal-metalloid amorphous alloys such as alloys containing Ti, Mn, Cr, Zr, Hf, Nb, etc., or C
Metal-metal amorphous alloys containing transition elements such as O, Hf, and Zr and rare earth elements as main components are also used.

These metal magnetic films (8), (9), (10)
As the film forming method in (11), a vacuum thin film forming technique typified by a vacuum evaporation method, a sputtering method, an ion blating method, a cluster ion beam method, etc. is adopted.

Note that the metal magnetic films (8), (9), (10)
), (11) may be a single layer film of the ferromagnetic alloy material, for example, S i 02. Tazos, Al
A multilayer film may be formed via an insulating film such as ZOS, ZrO, or Si3N1.

Here, when reproduction was performed using the magnetic head formed as described above, frequency characteristics as shown in FIG. 3 were obtained.

As shown in FIG. 3, the frequency characteristics of the magnetic head that is compatible with the present invention (indicated by A in the figure) show almost no waviness compared to the frequency characteristics of the conventional magnetic head (indicated by B in the figure). There wasn't. That is, it can be seen that in the magnetic head of this example, no pseudo gap that interferes with the original magnetic gap g is formed. Therefore, it can be said that the present invention can sufficiently prevent the formation of pseudo gaps.

Here, in order to make the structure of the magnetic head more clear, a method for manufacturing the same will be briefly explained with reference to the drawings.

First, as shown in FIG. 4, a non-magnetic substrate (17) is prepared, and uneven portions (18) are formed on the portion that will become the abutting surface so that it does not have a surface parallel to the magnetic gap surface.

Note that a winding groove is formed on one of the nonmagnetic substrates (not shown) after forming the above-mentioned uneven portions. Then, a first metal magnetic film (19) is formed on the surface on which the uneven portion (18) is formed.
) to flatten the uneven portion (18). At this time, the surface of the first metal magnetic film (19) opposite to the surface on which the uneven portion (18) is formed has an uneven shape that is approximately the same as the shape of the uneven portion (18).

Next, as shown in FIG. 5, the first metal magnetic film (
19) is polished to a mirror finish to such an extent that the uneven portion (18) is not exposed, thereby forming a flat surface (19a).

As a result, the first metal magnetic film (19) is formed uniformly, so there is no influence of film thickness distribution, and the film characteristics of the first metal magnetic film (19) are not deteriorated. That will no longer be the case.

Next, the flat surface (19) of the first metal magnetic film (19) is
a) A second metal magnetic film (20) is formed on top.

Thereafter, a portion (20a) of the second metal magnetic film (20) corresponding to the magnetic gap surface is mirror-finished. and,
After the non-magnetic substrate (17) and the non-magnetic substrates on which the winding grooves are formed are butted together via a gap spacer (not shown) and glass-fused, lines a-a and b in the figure
- Cut out by slicing at the position indicated by line b to complete the head chimp.

Here, the present invention is not limited to the magnetic head described above, but can also be applied to a magnetic head having a structure as shown in FIG. 7, for example.

The magnetic head shown in FIG. 7 has a non-magnetic substrate (21).

The abutting surfaces (21a) and (22a) of (22) are wave-shaped so as to be non-parallel to the magnetic gap surface, and the abutting surfaces (21a) and (22a) are coated with a first metal magnetic film. (23).

(24) and second metal magnetic film (25), (26
) are formed into films to form magnetic core halves, and the pair of magnetic core halves are joined and integrated by sandwiching a gap spacer.

The magnetic head shown in FIG. 8 also has a non-magnetic substrate (27).
, (28) butting surfaces (27a) , (28a
) is similar to the magnetic head shown in Figure 1, the unevenness is formed non-parallel to the magnetic gap surface, and the abutting surface (2
7a).

Track width regulating grooves (29) and (30) for regulating the track width are cut out on both sides of (28a), and the abutting surface (27a) includes the track width regulating grooves (29) and (30).

First metal magnetic films (31), (32) and second metal magnetic films (33), (34) are formed on (28a) to form a half magnetic core, and a gap spacer is sandwiched between the magnetic cores. A pair of core halves are joined and integrated.

Further, the shapes of the abutting surfaces (27a) and (28a) may be wavy as shown in FIG. 7.

Furthermore, the magnetic head shown in FIGS. 9 and 10 may have a shape as shown in FIGS. 9 and 10. The magnetic head shown in FIGS. 9 and 10 has substantially the same structure as the magnetic head shown in FIG. Since the only difference is the shape of the abutting surfaces of the non-magnetic substrates, explanations of the same members as shown in FIG. 8 will be omitted, and the same reference numerals will be used for the same members as shown in FIG. Attached.

First, the magnetic head shown in FIG. 9 has a non-magnetic substrate (27).
, (28) butting surfaces (27a) , (28a
) is formed at a predetermined angle with respect to the magnetic gap plane. Note that the second metal magnetic film (33)
, (34) on the side where the first metal magnetic film (31) is laminated.
) and (32) are formed to be parallel to the magnetic gap plane.

The magnetic head shown in FIG. 10 has a non-magnetic substrate (27).

The abutting surfaces (27a) and (28a) of (28) are cut out diagonally on both sides with respect to the magnetic gap surface, so that the shape is approximately ``■'' when viewed from the recording medium sliding surface. It was formed. Note that the second metal magnetic film (3
3), the first metal magnetic film on the side where (34) is laminated (
31).

The plane (32) is also formed parallel to the magnetic gap plane as in the previous example.

In both of the magnetic heads shown in FIGS. 7 and 10, the abutting surfaces of the non-magnetic substrates are non-parallel to the magnetic gap plane, so the abutting surfaces of the non-magnetic substrates are caused by so-called azimuth loss. There is no possibility that the bonding interface between the first metal magnetic film and the first metal magnetic film will operate as a pseudo gap.

Further, since the magnetic heads shown in FIGS. 7 to 10 can also determine the track width independently of the thickness of the metal magnetic film, the track width can be determined similarly to the magnetic head shown in FIG. Control is easy, and high efficiency can be achieved in the film forming process, etc. Therefore, yield and productivity are improved.

Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments.

〔Effect of the invention〕

As is clear from the above description, in the magnetic head according to the present invention, at least the portion near the magnetic gap of the abutting surfaces of the nonmagnetic substrates is formed non-parallel to the magnetic gap surface. The interface between the abutting surface and the first metal magnetic film formed on the abutting surface does not operate as a pseudo gap due to loss.

Further, the abutting surface that is non-parallel to the magnetic gap surface is flattened by the first metal magnetic film, and furthermore, the surface of the first metal magnetic film on which the second metal magnetic film is laminated is flattened. Therefore, the film characteristics of the first metal magnetic film will not deteriorate, and therefore, there is no risk that the electromagnetic conversion characteristics will also deteriorate.

Further, the interface between the first metal magnetic film and the second metal magnetic film formed on the flat surface of the first metal magnetic film acts as a pseudo gap because it becomes a bond between the metal thin films. There isn't.

Furthermore, since the magnetic head of the present invention can determine the track width regardless of the thickness of the metal magnetic film, it is possible to improve the track width accuracy and to improve the efficiency of this film forming process. .

Therefore, a magnetic head with improved recording and reproducing output characteristics and excellent productivity can be provided.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a magnetic head to which the present invention is applied, FIG. 2 is an enlarged plan view of the main part of the recording medium sliding surface, and FIG. 3 is a characteristic showing frequency dependence of reproduction output. It is a diagram. 4 to 6 show the manufacturing process of the magnetic head shown in FIG. 1. The figure is an enlarged cross-sectional view of the main part showing the polishing process of the first metal magnetic film.
The figure is an enlarged sectional view of a main part showing the second metal magnetic film forming step. FIG. 7 is an enlarged plan view of the main part showing another example of the magnetic head to which the present invention is applied, FIG. 8 is an enlarged plan view of the main part showing still another example, and FIG. 9 is an enlarged plan view of the main part showing still another example. FIG. 10 is an enlarged plan view of the main parts showing still another example. FIG. 11 is a perspective view showing an example of a conventional magnetic head. 6.7, 17, 21, 22, 27.28... Non-magnetic substrate 8.9.19, 23.24.31.32... First metal magnetic film 10, 11.20.25, 26 .33.34
...Second metal magnetic film g...Magnetic gap patent applicant Sony Corporation representative Patent attorney Sakae Koike Mitsui Tamura- Masaru Wabine Figure 4 Figure 5 b Figure 6 Figure 11 Figure 1 ．． Indication of the case 1988 Patent Application No. 11640 2 Name of the invention Magnetic head 3 Person making the amendment Relationship to the case Patent applicant address Tokyo Parts Co., Ltd. 8 Kitashina 6-7-35 No. 4 Agent 6 , Target of correction 7, Contents of correction <1) Mei 8 IlliF, page 4, line 17 to page 19
Across the lines, the statement ``Due to heat such as sputtering using vacuum thin fall formation technology during the formation of gold-gS magnetic films (3), (4)'' was replaced with ``Total magnetic film (3), (4) formed. Substrate after film (1). (2) Due to the heat of glass experts etc.'' (2) From line 14 on page 10 of the specification to line 17 on the same page, it is stated that ``Non-magnetic materials are not limited to ceramics, but include gold magnetic materials (8), (9), (10).
), (l l) during the heat treatment for forming the non-magnetic substrate (6). (7)'' was changed to ``Nonmagnetic materials are not limited to ceramics, but include substrates (ill), (IV
) is fused with glass, the non-magnetic substrate (6),
(7) Correct as J. (3) In the 11th line of page 21 of the specification, the statement ``on a totally magnetic film'' is corrected to ``on a metal magnetic film.'' (4) On page 21, line 13 of the specification, the description "first totally magnetic film" is corrected to "second metal magnetic film". that's all

Claims (1)

[Claims] A pair of magnetic core halves consisting of a non-magnetic substrate and a metal magnetic film formed along the abutting surfaces of the non-magnetic substrate are joined together, and a closed magnetic path is formed by the metal magnetic film. In the magnetic head configured, at least a portion near the magnetic gap of the abutting surfaces of the non-magnetic substrate has a non-parallel portion with the magnetic gap surface, and the metal magnetic film has a non-parallel portion of the abutting surface of the non-magnetic substrate. A magnetic head comprising a first metal magnetic film that flattens the parallel portion and a second metal magnetic film formed on the flat surface.