JPS6352310A - Composite magnetic head - Google Patents

Abstract

PURPOSE:To decrease the stress on magnetic materials arising from a difference in coefft. of thermal expansion in the process of forming heads so as to suppress the deterioration in magnetic characteristics and to improve reproduction efficiency by using thin soft magnetic Fe-Ga-Si films to form thin magnetic alloy films which constitute a main core to form a working gap. CONSTITUTION:The thin magnetic alloy films 3, 13 of the composite magnetic head, the magnetic core half bodies 1, 11 of which are constituted of oxide magnetic materials and the thin magnetic alloy films 3, 13 are formed of the thin soft magnetic Fe-Ga-Si films. The thin soft magnetic Fe-Ga-Si films contribute to the improvement in recording efficiency as the satn. magnetic flux density thereof is about 13,000 gauss which is larger than the satn. magnetic flux density of thin soft magnetic Fe-Al-Si films. The coefft. of thermal expansion thereof is about 130X10<-7>/ deg.C which is fairly approximate to the coefft. of thermal expansion of an oxide magnetic material (Mn-Zn ferrite); therefore, the microcracks, warpage, etc., of the oxide magnetic material, etc., in the process of forming the heads are suppressed and the reproduction efficiency is improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is directed to a so-called composite material in which the vicinity of the working gap is composed of a magnetic alloy thin film and the majority of the magnetic core half is composed of an oxide magnetic material. The present invention relates to magnetic heads, and specifically relates to improvements in the above-mentioned magnetic alloy Fij film.

[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 magnetic alloy thin film, characterized in that the magnetic alloy thin film is a Fe-Ga-Si based soft magnetic thin film. , which aims to improve the magnetic properties of magnetic alloy thin films and improve the recording and reproducing efficiency.

[Conventional technology]

For example, in magnetic recording and reproducing devices such as VTRs (video tape recorders), the density of information signals is increasing, and in response to this high density recording, magnetic powders such as Fe, Co, Ni, etc. are used as magnetic recording media. using ferromagnetic metal powder,
So-called metal tapes and so-called Kyo-bond tapes, in which a ferromagnetic metal material is directly deposited on a base film using a vacuum thin film forming technique such as f-bonding, are now being used.

This type of magnetic recording medium has high coercive force and residual magnetic flux density, and accordingly, the core material of the magnetic head is required to have a material with high saturation magnetic flux density and high magnetic flux density.

However, although heads using oxide magnetic materials such as ferrite, which have been widely used in the past, have high magnetic permeability, they have a low saturation magnetic flux density, so there is a limit to high density recording. On the other hand, heads using magnetic alloy materials such as Fe-Aff-Si alloys have a saturation magnetic flux density higher than that of ferrite and are capable of recording sufficiently on high coercive force magnetic recording media, but they cannot be used for -i. With the core thickness of the head shape, the effective i3 magnetic coefficient is low in the frequency range used, and the reproduction characteristics deteriorate.

Under these circumstances, the magnetic core parts are made of an oxide magnetic material, and a magnetic alloy material is deposited on each of these magnetic core parts as the main core material, and these magnetic alloy thin films are butted against each other to form an operating gap. A so-called composite magnetic head has been proposed.

[Problem that the invention seeks to solve]

However, in the composite magnetic head having the above-described structure, various problems remain due to the difference in thermal expansion coefficients between the 171 oxide magnetic material and the magnetic alloy thin film because of the large adhesion area.

That is, M n -Z n ferrite (
Thermal expansion coefficient: 115 to 120
50 to 160 xlO-7/°C), it is difficult to avoid distortion due to differences in thermal expansion coefficients. As a result, microcracks may occur in the magnetic core portion during head fabrication, or the magnetic properties of the magnetic alloy thin film may deteriorate. As a result, there is a problem in that the magnetic head has poor reproduction efficiency.

In addition, when a ferromagnetic amorphous alloy is used for the magnetic alloy thin film, the crystallization temperature of the amorphous material must be taken into account when joining the magnetic core halves by glass bonding, etc., so the bonding strength is large. It's getting harder to get. Therefore, it is conceivable to use an amorphous alloy having a crystallization temperature that satisfies the above conditions, but in this case, a sufficient saturation magnetic flux density cannot be obtained and there is a problem in terms of recording efficiency of the head.

In view of this situation, the present invention was proposed, and an object of the present invention is to improve the magnetic properties of a magnetic alloy thin film and provide a solution to composite magnetism with excellent recording and reproducing efficiency.

[Means for solving problems]

In order to improve the feelability of composite Tn, Fe-G
The a-Si based soft magnetic thin film has a high saturation magnetic flux density and at the same time has a flat expansion coefficient comparable to that of the oxide magnetic material that forms the magnetic core, making it useful as a magnetic alloy thin film for composite magnetic heads. We have obtained the following knowledge.

The composite magnetic head of the present invention was completed based on such knowledge, and in the composite magnetic head in which a magnetic core half is constituted by a 4Mf oxide material and a magnetic alloy thin film, the magnetic alloy thin film is is a Fe-Ga-Si based soft magnetic thin film.

[Effect]

Fe-Ga-Si soft magnetic y! The film has a total magnetic flux density of about 13,000 Gauss, which is larger than the Fe-Aβ-8L soft magnetic 3 film (11,000 Gauss).
Recording efficiency is improved.

At the same time, the thermal expansion coefficient of the Fe-Ga-Si soft magnetic thin film is about 130X10-'/''C, which is about 130X10-'/''C, which is about 115-1
20 Xl0-'/°C) Micro-cranks and warping of oxide magnetic materials during the head manufacturing process are suppressed, and the magnetic properties of the Fe-Ga-Si alloy can be fully demonstrated. , regeneration efficiency is improved.

〔Example〕

An embodiment of a composite 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 composite magnetic head to which the present invention is applied, and FIG. 2 is an enlarged plan view of the main part showing the sliding surface of the magnetic recording medium.

In this composite magnetic head, a magnetic core part (1),
(11) is formed of an oxide magnetic material such as Mn-Zn ferrite, and near the contact surface there are track width regulating grooves (2) and (12) for regulating the trunk width.
) is cut out on both sides in a roughly arc shape.

In addition, one magnetic core half (1) has a winding hole (21) for winding a coil that supplies signals to the magnetic head.
) are drilled.

The abutment surfaces of the respective magnetic core portions (1) and (11) include the insides of the track width regulating grooves (2) and (12), and extend from the front gap forming surface to the back gap forming surface, respectively. Continuously up to, high saturation magnetic flux density alloy,
In the present invention, magnetic alloy thin films (3) and (13) made of Fe-Ge-3t-based soft magnetic thin films are deposited,
It consists of magnetic core halves (1) and (11). Further, an operating gap g is formed by abutting parallel portions (3a) and (13a) formed on the contact surfaces of these magnetic alloy thin films (3) and (13). In addition, inside the trunk width regulating grooves (2) and (12), there are magnetic alloy thin films (3), which regulate the trunk width.
(13) Non-magnetic material (22) to prevent wear;
(22) is melt-filled.

Here, in the present invention, the above magnetic alloy thin film (3)
, (13) is composed of a Fe-Qa-Si based soft magnetic thin film.

In the Fe-Ga-Si-based soft magnetic thin film mentioned above, in order to ensure predetermined magnetic properties, the basic components Fe, Ga,
Regarding Si, Ga is 1 to 23 atomic %, Si is 9 to 31 atomic %, and the balance is Fe. However, the Fe content is 68-8
It is in the range of 4 atom%. When these basic components are out of the above range, it becomes difficult to ensure magnetic properties such as saturation magnetic flux density, magnetic permeability, and coercive force.

That is, when the composition of the Fe-Ga-Si-based soft magnetic thin MA is Fe5GabSic (where a, b, (each represents the composition ratio as atomic %)), the composition range is 68≦a+b It is assumed that the following relationships are satisfied: ≦84 1≦b≦23 9≦C≦31 a+b+c=100.

In addition, in the above Fe-Ga-Si-based soft magnetic thin film, F
A part of e may be replaced by r. 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 substitution is too large, not only will the deterioration of the saturation magnetic flux density become noticeable, but also the soft magnetic properties will deteriorate. ,
The amount of Co substitution relative to Fe is preferably suppressed to 0 to 15 atomic %.

That is, when the composition of the Fe-Ga-Si-based soft magnetic thin film is FedCo, Ga+Si9 (where d, e, f, and g each represent the composition ratio as atomic %), the composition range is , 68≦d+e≦84 0< e≦15 1≦f≦35 1≦g≦35 d+e×f+g=100.

Further, in order to further improve the corrosion resistance and wear resistance of the above-mentioned Fe--Ca--Si based soft magnetic film, Fe is added.

Ti, Cr,
M n .

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

At least one of Re, Ni, Pd, Pt, and Hr may be added.

That is, the composition of the Fe-Ga-Si-based soft magnetic thin film is Fet, CotGa, SimM+ (where h, i, j, k, and l each represent the composition ratio as atomic %, and M is Ti, Cr, Mn,
Zr.

Nb, MO, Ta, %J Ru, ○s, Ir,
Re.

Representing at least one type of Ni, Pd, Pt, Hf (7),
), the composition range satisfies the following relationships: 68≦h+i≦84 0≦1≦15 1≦j≦23 6≦≦31 0.5≦1≦6 h+i+j↓+1=100 - It may also be a Ga-5i based soft magnetic thin film. Addition amount of the above additive element M is 0.5 to 6 atomic%
The reason for this is that if the amount added is less than 0.5 at%, a sufficient effect in improving wear resistance and corrosion resistance cannot be expected, whereas if the amount added exceeds 6 at%, the soft magnetic properties may deteriorate. This is undesirable because it causes a decrease in saturation magnetic flux density. However, when two or more kinds of additive elements M are used, it is preferable that the amount of each additive element M is within the range of O to 5 atomic %.

In any of these cases, in the above compositional formula, part of Ga may be replaced by AN, and part of Si may be replaced by G.
It may be replaced with e.

Here, as a method for forming the Fe--Ga--Si based soft magnetic thin film, various conventionally known methods can be considered, but among them, a vacuum thin film forming technique is preferable.

The techniques for forming this vacuum thin film include sputtering, ion blasting, and vacuum deposition.

Examples include cluster ion beam method. In particular, sputtering may be performed in an atmosphere of an inert gas (such as Ar gas) containing oxygen gas or nitrogen gas to further improve the corrosion resistance of the resulting soft film.

In addition, as a method for adjusting the composition of each of the above component elements, I) Weigh each component element to a predetermined ratio and melt them in advance, for example, in a high frequency melting furnace to form an alloy ingot. , a method of using this alloy ingot as a material, ii) a method of preparing a single element material of each component and controlling the composition by the number of these materials, iii) a method of using a material of a single element of each component. A method of preparing a source and controlling the output (applied voltage) applied to these sources to control the evaporation speed and composition; iv) A method of implanting other elements while using an alloy as a source. , etc.

Note that the soft magnetic thin film formed by the above-mentioned vacuum thin film forming technology has a slightly high coercive force in its original state, and good soft magnetic properties cannot be obtained. It is preferable to remove strain and improve soft stone feelability.

In composite magnetic heads with such a configuration, composite magnetic heads were fabricated by varying the composition of the above-mentioned hexagonal alloy thin film (3L (13)), and the recording and reproducing characteristics and corrosion resistance of each were measured. Table 1 shows.For comparison,
Fe-, Af- in the magnetic alloy gt films (3) and (13)
Similar measurements were made for magnetism using a Si-based soft magnetic thin film, and the results are shown in Table 1.

Incidentally, in measuring the recording/reproducing characteristics described above, a composite head shown in FIG. 3 (described later) was used for reproduction in the case of the recording characteristics and for recording in the case of the reproducing characteristics.

In addition, the magnetic tape used has a coercive force of approximately 15,000e.
I used a moderate amount. Furthermore, the corrosion resistance of each head is
The surface of the membrane was observed after being immersed in tap water at room temperature for about one week. The corrosion resistance was evaluated based on the following surface conditions.

A: There is no change in the film surface and it remains mirror-like.

B: A state in which a thin layer of rust has formed on the film surface.

C: A state in which rust has occurred on the membrane surface.

Rust has occurred to the extent that D2M itself has disappeared.

(Leaving space below) Table 1 As is clear from this table, a composite magnetic head using a Fe-Ga-Si based soft magnetic thin film as a magnetic alloy thin film has a high saturation magnetic flux density (approximately 13,000' Gauss). )
It was found that the recording characteristics were improved due to the presence of the above.

The coefficient of expansion of the Fe-Ga-Si soft magnetic thin film is approximately 135 x 10/°C, and the Fe-Aβ-S
Compared to the i-based soft magnetic thin film (160xlO-'/°C), the thermal expansion coefficient of the magnetic core (for example ~fn-Zn ferrite) is much closer to 120xlQ-'z/°C, so when forming an IF alloy thin film, etc. The membrane stress, etc. generated in the process is considerably reduced. Therefore, microcracks and the like during the head manufacturing process can be effectively eliminated, and good playback characteristics can be obtained. Furthermore, a composite magnetic head with uniform head characteristics can be obtained, and the yield can be improved.

As described above, according to the present invention, it is possible to fully exhibit the magnetic properties of the magnetic alloy thin film. J combined magnetic head can be provided.

Furthermore, the Fe--Ga--Si based soft magnetic thin film has excellent wear resistance and corrosion resistance, so that the life of the head is extended and good recording and reproducing characteristics can be maintained over a long period of time. Moreover,
Even when the relative speed between the medium and the head increases, which is required for high-density recording, the initial electromagnetic conversion characteristics of the head can be maintained for a long period of time. Therefore, it is possible to eliminate spacing loss due to uneven wear of the sliding contact surface of the magnetic recording medium, so that a composite magnetic head suitable for recording and reproducing in a high frequency region can be provided.

Furthermore, since the present invention can be implemented without any changes to the conventional structure, manufacturing method, process, etc., it can be said that its practical value is extremely high.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various combinations of structures can be applied to the air head without departing from the spirit of the present invention.

For example, as shown in FIG. 3, the abutting surfaces of the magnetic core parts (30) and (31) made of oxide magnetic material are obliquely cut out to form inclined surfaces (30a) and (31a), respectively.
F on these slopes (30a) and (31a)
Magnetic alloy thin film (3) consisting of e-Ga-Si soft magnetic thin film
2) and (33) may be formed to form magnetic core halves, respectively, and a composite magnetic head may be provided in which the contact surfaces of these magnetic alloy thin films (32) and (33) serve as operating gear knobs g. In addition, each magnetic core part <30), (31) has a trunk width regulating groove (34).

(35) are notched to regulate the track width, and the trunk width regulating grooves (34), (35) and the three magnetic alloy films (3
2).

(33) is filled with non-magnetic materials (36) and (37) by melting. This composite magnetic head uses magnetic alloy 3
Since the trunk width can be controlled by controlling the thickness of the (32) and (33) films, it is possible to make the track narrower, making it a magnetic node suitable for high-density recording.

Alternatively, as shown in No. 41; 2I, the working gap g
The magnetic core part (40) inclined at a required angle with respect to (
Trunk width regulation a (42) is cut out on the oblique planes (40a) and (41a) of 41) and on both sides of the oblique planes (40a) and (41a) to regulate the track width.
), (43), (44), and (45), in which magnetic alloy thin films (46) and (47) made of Fe-Ga-Si soft magnetic thin films are continuously deposited. The present invention is also applicable to the first UA and the second UA by arranging the above-mentioned oblique planes (40a) and (41a), which serve as magnetic metal thin film forming surfaces, non-parallel to the operating gear knob g. The influence of the pseudo gap that occurs in the head shown in the figure can be eliminated.Furthermore, as shown in Fig. 50a),
(51a), and this inclined surface (50a).

Magnetic alloy thin films (52) and (53) made of Fe-Ga-Si soft magnetic thin films are deposited on (51a), and the track width is regulated by the thickness of the magnetic core parts (50) and (51). It may also be a composite magnetic head.

〔Effect of the invention〕

As is clear from the above explanation, in the composite magnetic head of the present invention, since the magnetic alloy 11i that constitutes the working gap and serves as the main core is a FeGa-Si soft magnetic thin film, oxides are removed during the head fabrication process. Stress contribution to the magnetic body due to the difference in orbital expansion coefficient between the magnetic material and the magnetic alloy thin film is reduced, and deterioration of magnetic properties can be suppressed. Therefore, the reproduction efficiency is significantly improved. Furthermore, since the Fe-Ga-3'i-based soft magnetic thin film has a large saturation magnetic flux density, it exhibits good recording characteristics for high coercive force magnetic recording media.

Further, according to the present invention, there is no need to change the manufacturing process of the composite magnetic head, and there is no need to worry about reductions in production efficiency or accuracy.

Furthermore, since distortion in the head manufacturing process can be effectively suppressed, microcranks, warpage, etc. can be effectively eliminated, and head characteristics and yields can be improved.

Furthermore, since the Fe--Ga--Si based soft magnetic thin film has excellent corrosion resistance and wear resistance, it is also advantageous in terms of the durability of the composite magnetic head.

These advantages, together with features such as ease of miniaturization, high productivity, high reliability, and high density recording derived from the composition of the composite magnetic head, are effective in improving the performance of the composite magnetic head. This makes it possible to provide a composite magnetic head with high practical value.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view showing an embodiment of a composite magnetic sensor to which the present invention is applied, and FIG. 2 is an enlarged plan view of the main part showing the surface in contact with a magnetic recording medium. FIGS. 3 to 5 are enlarged plan views of main parts showing the surface in contact with a magnetic recording medium according to other examples of the present invention.

Claims (1)

[Claims] 1. A composite magnetic head in which a magnetic core half is constituted by an oxide magnetic material and a magnetic alloy thin film, wherein the magnetic alloy thin film is a Fe-Ga-Si based soft magnetic thin film.