JPS63275005A - Composite magnetic head - Google Patents

Abstract

PURPOSE:To suppress the simultaneous production of a pseudo output by adopting the two-layer structure for the soft magnetic thin film in such a way of a 1st soft magnetic thin film and a 2nd soft magnetic thin film having the saturated magnetic flux density higher than that of the 1st soft magnetic thin film and forming a bonding boundary face between an oxide magnetic material and the 1st soft magnetic thin film not in parallel with the magnetic gap forming face so as to eliminate the saturation of the magnetic flux near the magnetic gap thereby improving the recording and reproducing efficiency. CONSTITUTION:The soft magnetic thin film consists of the 1st soft magnetic thin film and the 2nd soft magnetic thin films 5, 6 having a higher saturated magnetic flux density than that of the 1st soft magnetic thin films 3, 4, the bonded boundary face between the oxide magnetic material and the 1st soft magnetic thin films 3, 4 has a art not in parallel with the magnetic gap forming face and the bonded boundary face between the 1st soft magnetic thin films 3, 4 and the 2nd soft magnetic thin films 5, 6 has a part nearly in parallel with the magnetic gap forming face. Thus, the saturation of the magnetic flux hardly takes place, production of cracks is suppressed and the problem of a pseudo gap is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a composite magnetic head suitable for recording and reproducing information on and from a high coercive force magnetic recording medium such as a so-called metal tape. The present invention relates to a composite magnetic head in which most of the half body is made of an oxide magnetic material, and the part near the magnetic gap is made of a soft magnetic alloy thin film.

B1 Summary of the Invention The present invention provides a composite magnetic head in which a magnetic core half is constituted by an oxide magnetic material and a soft magnetic thin film, in which a soft magnetic fi film is combined with a first soft magnetic iiJ film and the first soft magnetic thin film. The second soft magnetic thin film has a two-layer structure having a saturation magnetic flux density higher than the saturation magnetic flux density of the magnetic thin film, and the bonding interface between the oxide magnetic material and the first soft magnetic thin film is made non-parallel to the magnetic gap forming surface. By doing so, the saturation of the magnetic flux near the magnetic gap is eliminated and recording/
This aims to improve the reproduction efficiency and at the same time suppress the occurrence of pseudo output.

C6 Conventional technology For example, in magnetic recording and reproducing devices such as VTRs (video tape recorders), information signals are being recorded at higher density. So-called meckle tapes using ferromagnetic metal powder such as Ni, and so-called vapor deposition tapes in which the above-mentioned ferromagnetic metal materials are directly deposited on a base film by vapor deposition, etc., are now being used.

This type of magnetic recording medium has high coercive force and residual g flux density, so the core material of the magnetic helad that performs electromagnetic conversion of information signals is required to have a sufficiently high saturation magnetic flux density commensurate with the coercive force of this medium. be done. Furthermore, especially when recording and reproducing are performed using the same magnetic head, it is required to have not only the above-mentioned saturation magnetic flux density but also a sufficiently high i3 magnetic flux in the applicable frequency band.

However, although the ferrite head that has been widely used in the past has high magnetic permeability, it has a low saturation magnetic flux density, and therefore cannot provide sufficient recording characteristics for the above magnetic recording media.
On the other hand, magnetic heads made of soft magnetic alloy materials such as Fe-Ae-Si alloys have a large saturation magnetic flux density and exhibit good recording characteristics for high coercive force magnetic recording media.
Cores in commonly used head shapes have low effective magnetic permeability in the frequency band used, resulting in degraded reproduction characteristics.

Under such circumstances, a so-called composite magnetic material is constructed in which a magnetic core half is constructed using a composite magnetic material of ferrite and Fe-AN-3i alloy, and the abutting surfaces of these Fe-Al-3i alloy thin films are used as a magnetic gap. A head has been developed and put into practical use.

For example, in video tape recorders for broadcasting stations, 90μ
A groove with a slope at a predetermined angle is formed on the ferrite substrate because a track width as wide as 1.5 m is required, and a pseudo gap is likely to occur at the interface between the ferrite and the soft magnetic alloy material due to the shape effect. formed, and on top of this Fe
A magnetic head has been developed in which a -Al4-3i alloy thin film is deposited to a thickness of about 30 am, and then the surface is ground flat to obtain a predetermined track width.

Problems to be solved by the D0 invention However, in such a magnetic head, especially Fe-
Aj! Since the saturation magnetic flux density of the -3i alloy itself is not very high, the problem remains that its magnetic properties are not sufficient for recording on a high coercive force metal tape.

As a soft magnetic alloy material with a high saturation magnetic flux density, Fe-Ga-3i alloys, etc. are useful, as previously reported by the applicant, but the thickness is limited by distortion,
There is a limit to securing a wide track width as mentioned above. For example, if a film of about 30 μm of Fe-Ga-5i alloy material is applied to ferrite, many cracks occur, and normally 5 g
The limit is around m.

Therefore, the present invention has been proposed in view of the above-mentioned conventional situation, and aims to eliminate saturation of magnetic flux in a magnetic film, improve recording/reproducing efficiency, and furthermore, it aims to improve recording/reproducing efficiency. The purpose of the present invention is to provide a magnetic head with low yield and excellent reliability.

Means for Solving Problem E6 In order to achieve the above-mentioned object, the present invention comprises a magnetic core half made of an oxide magnetic material and a soft magnetic thin film, and the magnetic core halves are butted together. In the composite magnetic head, the soft magnetic thin film includes a first soft magnetic thin film and a second soft magnetic thin film having a saturation magnetic flux density larger than the saturation magnetic flux density of the first soft magnetic thin film, and the two soft magnetic thin films face each other, the bonding interface between the oxide magnetic material and the first soft magnetic thin film has a portion non-parallel to the magnetic gap forming surface, and the first soft magnetic thin film and the first soft magnetic thin film The bonding interface of the second soft magnetic thin film is characterized in that it has a portion substantially parallel to the magnetic gap forming surface.

In a magnetic head made of a composite material of an F8-active oxide magnetic material and a soft magnetic alloy thin film, it is preferable that the soft magnetic alloy thin film is an oblique film in order to avoid spurious output from the viewpoint of recording/reproducing characteristics. However, forming a diagonal film requires a certain amount of film thickness, which may be difficult depending on the material. For example, Fe-
Although Ga-3i-Ru materials have a high saturation magnetic flux density, they have poor workability and are difficult to form into the diagonal film.On the other hand, although sendust has some workability, its magnetic flux density is not so high.

In the present invention, taking advantage of the advantages of both, a diagonal film is formed using sendust, and then a high saturation magnetic flux film such as a Fe-Ga-3i-Ru alloy thin film is deposited as a parallel film, thereby preventing the occurrence of cracks. problem and saturation magnetic flux density problem at the same time.

In other words, the soft magnetic alloy film in contact with the ferrite is
By using a material that can be deposited to a certain degree of thickness, such as an e-Al-3i alloy thin film, and by making the interface with the ferrite non-parallel, the track width can be secured and a pseudo gear can be formed. do not have.

In addition, since the area near the magnetic gap is composed of an alloy thin film with a higher saturation magnetic flux density, saturation of the magnetic flux is less likely to occur, and the thin film only needs to be slightly thick, so no cracks will occur. Note that since the soft magnetic alloy gJ having a two-layer structure is bonded between metals, it does not function as a pseudo-gamb.

G. Embodiment Next, an embodiment to which the present invention is applied will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the magnetic head of this embodiment includes magnetic core parts (1) and (2) made of an oxide magnetic material such as Mn-Zn ferrite, and a first soft magnetic alloy. Thin films (3), (4) and second soft magnetic alloy thin film (5)
, (6) The magnetic core halves (1) and (n) whose main constituent elements are the two-layered magnetic thin film portion are integrally joined together.

Examples of the oxide magnetic material constituting the magnetic core parts (1) and (2) include Mn-Zn ferrite and Ni.
-Zn ferrite or the like is used. Further, this oxide magnetic material may be either a single crystal oxide magnetic material or a polycrystalline oxide magnetic material, and furthermore, the single crystal oxide magnetic material and the polycrystalline oxide magnetic material are combined by so-called hot heating. It may be a bonded body that is integrated by a pressure treatment method or the like.

The first soft magnetic alloy thin films (3) and (4) are formed on the slopes (1a) and (2a) of the ends of the magnetic core parts (1) and (2) in the abutting direction. , the track width 1 of the magnetic gap, which will be described later, is determined by this film thickness.
'w' is secured.

Therefore, this first soft magnetic alloy fillta (3
), (4) are required to be able to form a film with a certain thickness and have a saturation magnetic flux density that is at least higher than that of ferrite. For example, Fe
- An Al-3i alloy thin film is used. Fe-An! −
A normal composition is selected as the composition of the 3i alloy thin film,
If necessary, conventionally known additive elements may be added.

In addition, the first soft magnetic alloy thin films (3) and (4) are connected to the slopes (la) of the magnetic core parts (1) and (2),
(2a) Since it is formed on the magnetic core part (1)
, (2) is non-parallel to the magnetic gap described later and is tilted at a predetermined angle, so this junction interface no longer functions as a pseudo gap due to so-called azimuth loss. There is.

In addition, at the bonding interface between the first soft magnetic alloy thin film (3), (4) and the magnetic core part (1), (2), there is a gap between the Fe-Al4-Si alloy thin film and the ferrite during heat treatment. In this example, Si
Intermediate films (7) and (8) made of n, Cr, etc. are provided. The intermediate films (7) and (8) may be made of any material as long as it can achieve the above object, and both magnetic and non-magnetic materials can be used.

On the other hand, the second soft magnetic alloy films H(5) and (6) are formed so as to cover the first soft magnetic alloy thin films H(3) and (4). The soft magnetic alloy thin films (5) and (6) are butted against each other via a gap spacer (not shown), and the magnetic gap g
is configured. The track width of the magnetic gap g is Tw
are the first soft magnetic alloy 'gI films (3), (4)
The abutting surfaces of the magnetic core parts (1) and (2) are regulated by scraping diagonally at both ends in the width direction, and the space thus formed ensures contact characteristics and improves wear resistance. Therefore, non-magnetic materials such as glass (9)
is filled.

Since the second soft magnetic alloy thin films (5) and (6) do not need to be very thick, there is no need to consider cracks, and therefore they are made of a material with as high a saturation magnetic flux density as possible [at least the first material described above]. Soft magnetic alloy filtl (3).

(4) A soft magnetic alloy material with a higher saturation magnetic flux density) is used.

Such soft magnetic alloy materials include, for example, Fe-Ga-
3i alloy, Fe-Aj! -Ge-based alloy.

Fe-Ga-Ge alloy, Fe-3i-Ge alloy, F
Examples include soft magnetic alloy materials having high saturation magnetic flux density and excellent soft magnetic properties, such as e=Co-3i alloy and Fe-Co-5i-AN alloy.

For example, in the case of Fe-Ga-3i alloy material, when its composition is expressed by the following formula % formula % (where a, b, and c each represent the composition ratio as atomic %), the composition range is 68 Those satisfying the following relationships are used: ≦a+b≦84 1Sb≦23 9≦C≦31 a+b+c-100.

Further, in the above Fe-Ga-5i alloy material, Fe
may be partially replaced with Co. In this case, as Co increases, not only the saturation magnetic flux density but also corrosion resistance and wear resistance improve, but if the amount of CO replacement is too large, the saturation magnetic flux density deteriorates significantly. Not only will the soft magnetic properties deteriorate, so Fe
C against.

It is preferable to suppress the amount of substitution to θ to 15 atomic %.

Furthermore, in order to further improve the corrosion resistance and wear resistance of the Fe-Ga-5i alloy material, Fe is added.

Ti, Cr in an alloy whose basic composition is Ga, Co (including those in which part of Fe is replaced with Co), and St.

Mn, Zr, Nb, Mo, Ta, W, Ru, Os.

At least one of Rh, Ir, Re, Ni, Pd, PC, If, and V may be added. In this case, since the rate of decrease in saturation magnetic flux density depending on the amount added differs for each added element,
The amount added is appropriately set within a predetermined range for each added element. In particular, Ru shows good effects in terms of wear resistance and is suitable as an additive element.

The amount of Ru added is 15 atomic % or less from the viewpoint of magnetic properties.

Note that the second soft magnetic alloy fillll (5), (6
) and the first soft magnetic alloy thin films (3) and (4) are approximately parallel to the magnetic gap g, but since the alloy thin films are bonded together, there is no risk of a pseudo-image gap. .

As a method for forming the above-mentioned first soft magnetic alloy Eill (3), (4) and second soft magnetic alloy 11111 (5), (6), various conventionally known methods can be considered. The method of vacuum thin film formation technology is suitable.

Examples of this vacuum thin film forming technique include sputtering method, ion blating method, vacuum evaporation method, cluster ion beam method, and the like.

In particular, an inert gas (A
Sputtering may be performed in an atmosphere (such as r gas) to further improve the corrosion resistance, etc. of the resulting soft magnetic f111g.

The soft magnetic alloy lll1 formed into a film using the vacuum thin film forming technique, etc., exhibits a slightly high coercive force in its original state, and good soft magnetic properties cannot be obtained, so it is heat-treated to remove distortion of the film. , it is preferable to improve the soft magnetic properties.

A magnetic core half ( 1), (
■) is the second soft magnetic alloy thin 1! (5) , (
6) to form a magnetic head by facing each other and abutting each other, one of the magnetic core halves (II) is provided with a coil winding groove (10) to define the depth of the magnetic gap. At the same time, a coil is wound around the magnetic head for supplying a drive signal to the magnetic head.

In the magnetic head having the above configuration, the cross-sectional area of the magnetic core decreases as it approaches the surfaces facing each other in the magnetic gap g. Since the volume ratio of the magnetic alloy thin films (5) and (6) increases, the saturation magnetic flux density increases. Therefore, saturation of the magnetic flux in each part of the head is less likely to occur, resulting in a magnetic head with excellent recording and reproducing characteristics.The above-described magnetic head is manufactured through the following steps. Hereinafter, a method for manufacturing the magnetic head will be described with reference to FIGS. 3A to 3G.

First, as shown in FIG. 3A, a substrate (11) made of an oxide magnetic material is prepared, and a groove (12) is cut into the substrate to form a slope (12a). This groove (12)
The angle of inclination of the slope (12a) formed by this may be appropriately set according to the desired trunk width, azimuth angle, etc., but here it is set to about 15 degrees with respect to the surface of the substrate (11).

Next, as shown in FIG. 3B, on this substrate (11),
In this example, S
An intermediate film (13) of ing, Cr, etc. is deposited thereon, and a Fe--An-3i alloy'gi film (14) is deposited thereon as a first soft magnetic alloy thin film. These intermediate film (13) and Fe-AIV, -3i alloy thin film (14) are formed by vacuum thin film forming technology, and in particular, the Fe-Al-3i alloy thin film (14) is deposited to a thickness of about 30 μm.

Next, as shown in FIG. 3C, the Fe-Aff-Si
SiO□ is applied on the alloy film (14) to prevent oxidation.
An anti-oxidation film (15) consisting of etc.
2) A non-magnetic material (16) such as glass is embedded in the depression.

Note that this oxidation prevention film (I5) and the above-mentioned intermediate film (13)
may be omitted in some cases.

After that, the surface of the substrate (11) is polished, and the surface of the substrate (11) is polished.
Fe-Al-3i alloy thin film (14) on the flat surface of 1)
At the same time, as shown in the third diagram, the slope (12
a) Fe-Aj deposited on top! -5i alloy thin film (1
4) Expose the end face.

Next, as shown in Figure 3, the Fe-A1-3i alloy thin film (14) on the slope (12a) is left and the substrate (1)
1) A track width regulating groove (17) is cut to define the track width of the magnetic gap. This track width regulating groove (1
7) is a groove having an inclination of, for example, about 45°.

As shown in FIG. 3F, the substrate (11), which has been grooved and has a roughly defined track width, is coated with a saturated film having a higher saturation than the Fe-Al-3i alloy thin film (14) so as to cover the entire surface of the substrate (11). A soft magnetic alloy thin film (18) having a magnetic flux density is deposited, and a non-magnetic material (not shown) is further formed to form a gap. The above soft magnetic alloy thin film (1
8) includes Fe-Ga-3i- which has a high saturation magnetic flux density.
A functional material such as Ru is used, also deposited by vacuum thin film formation techniques such as sputtering.

Magnetic core half block (2
1) and (22), a coil winding groove (19
) and a glass groove (20) for inserting the fused glass, and as shown in FIG. After that, it is cut at the center between the trunk and the track (X1- in the figure and the Xs-Xz'UA position) to obtain the magnetic head shown in FIGS. 1 and 2.

Here, the substrate (11) is the magnetic core part (1) of the magnetic head.
.

(2), and corresponds to Fe-A1. -3i alloy thin 1
1a (14) Ka'l 1 soft magnetic alloy Fjil! (
3), (4) D. Soft magnetic alloy thin 11! (18) corresponds to the second soft magnetic alloy thin films (5) and (6).

By the way, the method for manufacturing the magnetic head of the present invention is not limited to the above-mentioned process, and various methods can be considered.For example, in the previous example, Fe-Al-3i alloy yi
Track width regulating grooves were cut after the film was deposited, but Fe-Al-5
A three-layer i-based alloy film may be applied.

That is, first, as shown in FIG. 4A, a groove (32) having a slope (32a) is cut in the substrate (31) in the same way as in the previous example, and then immediately this slope (32a) is cut as shown in FIG. 4B. 32
Track width regulating grooves (33), (34) at both ends of a)
to cut.

Next, as shown in FIG. 4C, a Fe-Al-5i alloy fi film (35) is deposited and then surface polished as shown in FIG. The Fe-Al-3i alloy thin film (35
) Soft magnetic alloy 1fl (
36) and a non-magnetic material (not shown) to serve as a gap spacer.

Thereafter, as in the previous example, these soft magnetic alloy films'm (
36) The two pieces are brought together so that they face each other, and the glass is fused to complete the magnetic head.

In addition, in this case as well, the above-mentioned Fe-Al! -3i alloy thin @
It goes without saying that an intermediate film or the like may be formed between (35) and the substrate (31).

The magnetic recording medium contacting surface of the magnetic head manufactured by the above steps is as shown in FIG.

That is, the first soft magnetic alloy thin film Fe-Al1-
The thin #5i alloy (35) is deposited not only on the slope (32a) but also on the slopes (33a) and (34a) formed by the track width regulating grooves (33) and (34), It plays the role of securing the track width and the volume of the high saturation magnetic flux density material in the vicinity of the magnetic gap. Further, the soft magnetic alloy thin film (36), which is the second soft magnetic alloy 11118, faces the magnetic gap in a bankrupt manner, as in the previous example, and prevents saturation of the magnetic flux in the vicinity of the magnetic gap. In addition, the track width regulation groove (3
3) The space formed by (34) is filled with a non-magnetic material (37) such as glass by glass fusion.

Also in such a magnetic head, since the soft magnetic alloy film has a two-layer structure, problems such as magnetic flux saturation, pseudo gaps, and cracks can be solved.

Effects of H1 Invention As is clear from the above explanation, oxide magnetic materials and soft magnetic alloys IT! In a magnetic head made of a composite material with I, the part in contact with the oxide magnetic material is made of a soft magnetic alloy material that can ensure a certain film thickness, and the bonding interface between these is inclined with respect to the magnetic gap. This eliminates the problem of pseudo gaps, and at the same time makes it possible to secure a somewhat wide track width. In addition, since the vicinity of the magnetic gap is made of a soft magnetic alloy material with a high saturation magnetic flux density, saturation of the magnetic flux is less likely to occur, and the thickness of the soft magnetic alloy material is also reduced, which reduces the occurrence of cracks. It can be suppressed.

Therefore, according to the present invention, the recording/reproducing ability is high;
Moreover, it is possible to provide a magnetic head that is excellent in terms of authenticity and yield.

In addition, in the magnetic head of the present invention, a soft magnetic alloy thin film having a high saturation magnetic flux density is simply deposited using the same method as the non-magnetic film before forming the non-magnetic film to serve as the gap spacer. There is no significant increase in manufacturing costs, and there is no problem in terms of productivity.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of a magnetic head to which the present invention is applied, and FIG. 2 is a plan view showing its surface in contact with a magnetic recording medium. 3A to 3G show an example of the manufacturing process for manufacturing the magnetic head shown in FIG. 1 according to the process order, and FIG. 3A is a side view showing the groove forming process; B is a side view showing the first soft magnetic alloy thin film forming step, FIG. 3 C is a side view showing the glass filling step, the third drawing is a side view showing the surface polishing step, and FIG. 3 E is a track width regulating groove. FIG. 3F is a side view showing the cutting process, FIG. 3F is a side view showing the second soft magnetic alloy thin film forming process, and FIG. 3G is a perspective view showing the magnetic core half block joining process. FIGS. 4A to 4E are side views showing another example of the method for manufacturing a magnetic head in the order of steps. FIG. 4A is a groove forming process, FIG. 4B is a track width regulating groove cutting process, and FIG. 4C shows the first soft magnetic alloy thin film forming step, the fourth drawing shows the plane polishing step, FIG. 4E shows the second soft magnetic alloy thin film forming step, and FIG. 5 shows the steps shown in FIGS. 4A to 4. FIG. 4 is a plan view showing the magnetic recording medium contacting surface of the magnetic head manufactured by the process shown in FIG. 4E.

Claims (1)

[Claims] In a composite magnetic head in which a magnetic core half is constituted by an oxide magnetic material and a soft magnetic thin film, and the magnetic core halves are butted, the soft magnetic thin film is a first soft magnetic thin film. and a second soft magnetic thin film having a saturation magnetic flux density greater than the saturation magnetic flux density of the first soft magnetic thin film, the second soft magnetic thin films facing each other in the magnetic gap portion, and the oxide magnetic material The bonding interface between the first soft magnetic thin film and the first soft magnetic thin film has a portion non-parallel to the magnetic gap forming surface, and the bonding interface between the first soft magnetic thin film and the second soft magnetic thin film is approximately the same as the magnetic gap forming surface. A composite magnetic head characterized by having a parallel portion.