JPH0648530B2 - Magnetic head - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a magnetic head, and in particular, a magnetic gap is formed by abutting ferromagnetic metal thin films to each other via a gap spacer, and The present invention relates to a so-called composite type magnetic head which is mostly formed of a ferromagnetic oxide.

[Outline of Invention]

According to the present invention, a magnetic core half is formed from a magnetic core part made of a ferromagnetic oxide and a ferromagnetic metal thin film formed by a vacuum thin film forming technique on the ferromagnetic thin film forming surface of the magnetic core part. In a magnetic head in which magnetic metal thin films are made to face each other in series to form a magnetic gap, and the ferromagnetic thin film forming surface and the magnetic gap forming surface are inclined at a predetermined angle on the contact surface of the magnetic recording medium. The ferromagnetic thin film forming surface is inclined near the magnetic gap at an angle θ of 10 ° <θ ≦ 35 ° with respect to the magnetic gap forming surface, and 45 ° ≦ with respect to the magnetic gap forming surface.
It is intended to increase the track width and to provide a magnetic head which is less affected by crosstalk and pseudo gaps by constituting it with an inclined surface inclined at an angle α of α ≦ 70 °.

[Conventional technology]

In the field of magnetic recording, high-density recording of information signals and high frequency are being promoted, and in response to this, magnetic powders such as powders of ferromagnetic metals such as Fe, Co and Ni are used as magnetic recording media. A so-called metal tape using the above, a so-called vapor deposition tape in which a magnetic metal material is directly deposited on a base film by a vacuum thin film forming technique such as vapor deposition, and the like have been put into practical use.

By the way, since this kind of magnetic recording medium has high coercive force and residual magnetic flux density, the head material of the magnetic head used for recording / reproducing is required to have high saturation magnetic flux density and high magnetic permeability. For example, a ferrite material, which has been widely used as a head material, has a low saturation magnetic flux density and cannot cope with the above-described high coercive force.

Therefore, conventionally, in order to correspond to the magnetic recording medium having a high coercive force, a ferromagnetic metal thin film having a high saturation magnetic flux density is deposited on a non-magnetic substrate such as ceramic or a magnetic substrate such as ferrite. A so-called composite type magnetic head has been proposed in which thin films are butted against each other to form a magnetic gap.

However, in these conventional composite type magnetic heads,
There are many problems in terms of productivity and reliability.

For example, a composite magnetic head has been proposed in which ferromagnetic metal thin films sandwiched by non-magnetic substrates such as ceramics are abutted with each other, and the thickness of the ferromagnetic metal thin films is set as a track width. Since the entire magnetic path is composed of only a thin ferromagnetic metal thin film, not only does the magnetic resistance increase and the efficiency decreases, but the ferromagnetic metal thin film is deposited to a certain thickness so that the track width becomes a predetermined value. Therefore, there is a problem that it takes a long time to form a film.

Alternatively, a composite type magnetic head in which the magnetic core portion is made of a ferromagnetic oxide such as ferrite and a magnetic metal thin film is adhered to the magnetic gap forming surface of each of these magnetic core portions is proposed. Is located in a direction in which the magnetic path and the metal thin film are orthogonal to each other, the influence of the pseudo gap is large,
In addition, there is a possibility that eddy current loss may occur and the reproduction output may be reduced, and there is a problem that sufficient reliability cannot be obtained.

Therefore, in order to eliminate the above-mentioned drawbacks, the applicant of the present application
Japanese Patent Application No. 58-250988 or Japanese Patent Application No. 60-153745
In the specification, a ferromagnetic metal thin film is obliquely applied,
We proposed a magnetic head with improved reliability and productivity.
In particular, the magnetic head described in Japanese Patent Application No. 60-153745 has a bend in the middle of the surface on which the ferromagnetic thin film is formed, and even a thin ferromagnetic metal thin film has a certain track width. It is possible to secure the above-mentioned characteristics, there is no damage due to cracking, and the reliability and productivity are excellent.

[Problems to be solved by the invention]

The present invention aims to further improve such a magnetic head.

That is, in the above-described magnetic head, the optimum value of the inclination angle of the ferromagnetic thin film formation surface is obtained in consideration of the crosstalk, the pseudo gap, the reproduction output, etc. in addition to the track width expansion, and the electromagnetic conversion characteristics are excellent and the reliability is high. The purpose is to provide a magnetic head that is also advantageous in terms of productivity.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a magnetic core portion made of a ferromagnetic oxide and a ferromagnetic metal thin film formed by a vacuum thin film forming technique on the ferromagnetic thin film forming surface of the magnetic core portion. A magnetic core half body is formed, and a magnetic gap is formed by arranging the ferromagnetic metal thin films to face each other in series, and at the contact surface of the magnetic recording medium, the ferromagnetic thin film forming surface and the magnetic gap forming surface are formed. Is a magnetic head inclined at a predetermined angle, and the ferromagnetic thin film forming surface is 1 in the vicinity of the magnetic gap with respect to the magnetic gap forming surface.
An inclined surface inclined at an angle θ of 0 ° <θ ≦ 35 ° and an angle α of 45 ° ≦ α ≦ 70 ° with respect to the magnetic gap forming surface
It is characterized in that it is composed of an inclined surface inclined at.

[Action]

Since the inclination angle of the ferromagnetic thin film forming surface is set to an angle θ of 10 ° <θ ≦ 35 ° with respect to the magnetic gap forming surface in the vicinity of the magnetic gap, even if the ferromagnetic metal thin film is thin. The track width is secured.

Further, by setting the tilt angle of the surface on which the ferromagnetic thin film is formed to the angle θ, the interface between the ferromagnetic metal thin film and the ferromagnetic oxide does not act as a pseudo gap.

Further, by setting the angle of the inclined surface distant from the magnetic gap to 45 ° ≦ α ≦ 70 °, the volume of the magnetic core portion near the magnetic gap can be secured, and the ferromagnetic metal thin film and the ferromagnetic oxide can be secured. The contact area with and the reproduction characteristics are improved.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an external perspective view showing an example of a composite type magnetic head to which the present invention is applied, and FIG. 2 is an enlarged plan view of an essential part showing a contact surface of the magnetic recording medium.

In this magnetic head, the magnetic core portions (11) and (12) are formed of a ferromagnetic oxide, for example, Mn-Zn ferrite, and the joining surface of these magnetic core portions (11) and (12) is cut diagonally. On the missing ferromagnetic thin film forming surfaces (13) and (14), a ferromagnetic material which is a high-permeability alloy, for example, a Fe-Al-Si alloy film is continuously formed from the front gap forming surface to the back gap forming surface. The metal thin films (15) and (19) are deposited and formed by the vacuum thin film forming technique to form magnetic core halves (21) and (22), respectively. The pair of magnetic core halves (2
1) and 22) are butted against each other via a gap material such as SiO _{2 so} that the contact surfaces of the ferromagnetic metal thin films 15 and 19 are the magnetic gap g having the track width Tw. .

Here, the ferromagnetic metal thin film forming surfaces (13) and (14) are the magnetic core halves (21) and (2) when viewed from the contact surface of the magnetic recording medium.
2) the joining surface which is the abutting surface, that is, the first inclined surfaces (13a) and (14a) inclined at an angle of θ with respect to the magnetic gap forming surface (16) and the magnetic gap forming surface (16). The second inclined surface (13b), (14
b) a bent part consisting of and with an obtuse angle in the middle
It has (13c) and (14c).

Then, the ferromagnetic metal thin films (15), (19) of the portions adhered on the first inclined surfaces (13a), (14a) inclined at an angle of θ with respect to the magnetic gap forming surface (16). The magnetic gaps g are formed by abutting each other.

The angle θ formed by the first inclined surfaces (13a), (14a) arranged near the magnetic gap g and the magnetic gap forming surface (16) is set within the range of 10 ° <θ ≦ 35 °. It When the inclination angle θ exceeds 35 °, the ferromagnetic metal thin films (15) and (19) must have a sufficient film thickness in order to obtain a head having a wide track width, which deteriorates the productivity. However, it is not preferable. On the contrary, when the inclination angle θ is 10 ° or less, the magnetic gap g and the first inclined surfaces (13a) and (14a) approach parallel to each other, so that crosstalk or pseudo gap occurs and the recording / reproducing characteristics deteriorate. .

Further, the second inclined surfaces (13b) and (14b) formed continuously with the first inclined surfaces (13a) and (14a), and the magnetic gap forming surface.
The angle α formed by (16) is set within the range of 45 ° ≦ α ≦ 70 °. If the inclination angle α exceeds 70 °, the volume of the magnetic core portions (11) and (12) is reduced in the vicinity of the magnetic gap g, the reproduction output is reduced, or the wear resistance is deteriorated. . On the contrary, if the inclination angle α is less than 45 °, the crosstalk becomes large and the reliability of the head deteriorates, which is not preferable.

In addition, in the vicinity of the magnetic gap g, that is, on both sides of the magnetic gap g on the contact surface of the magnetic recording medium, a non-magnetic layer for controlling the track width and preventing abrasion of the ferromagnetic metal thin films (15), (19) is provided. The magnetic materials (17) and (18) are melt-filled.

In this embodiment, the magnetic core portions (11), (12)
The track width regulating grooves (11b), (12b) formed on the magnetic recording medium are formed such that the shape of the interface between the non-magnetic material (18) and the ferromagnetic oxide is bent. The ferromagnetic oxide facing the track width regulating grooves (11b), (12b) is opposed to this by cutting with a curved surface such that the shape of the above interface becomes a substantially arc shape when viewed from the medium facing surface. While maintaining a distance from the ferromagnetic metal thin films (15) and (19),
Due to the symmetrical balance of the groove, the stress on the ferromagnetic oxide during processing is made small, and the magnetic core (11),
The generation of microcracks in (12) may be prevented.

On the other hand, as the material of the ferromagnetic metal thin films (15) and (19),
A ferromagnetic amorphous metal alloy, a so-called amorphous alloy (for example, one or more elements of Fe, Ni, Co and P, C, B,
Alloy consisting of one or more elements of Si, or Al, Ge, Be, Sn, In, Mo, W, T containing this as a main component
A metal-metalloid amorphous alloy such as an alloy containing i, Mn, Cr, Zr, Hf, Nb, or the like, or C
O-, Hf, Zr, and other transition elements and rare-earth elements as the main components, metal-metal amorphous alloys), Fe-Al-
Sendust alloy, which is a Si-based alloy, Fe-Al-based alloy,
Fe-Si alloys, Fe-Si-Co alloys, permalloys, etc. can be used, and the film deposition methods are represented by flash vapor deposition, vacuum vapor deposition, ion plating, sputtering, cluster ion beam method and the like. Vacuum thin film forming technology is adopted.

When the above Fe-Al-Si alloy is used, the composition range of Fe, Al, and Si as the main components is Al.
Content of 2 to 10% by weight, Si content of 4 to 15
%, And the balance is Fe. In other words, the Fe-Al-Si alloy _{Fe a Al b Si c (a} , b, c represents the weight ratio of each component.) When expressed in, the composition range 70 ≦ a <95 2 ≦ It is desirable that b ≦ 10 4 ≦ c ≦ 15. If the amount of Al or Si is too small, or vice versa, the magnetic properties of the Fe-Al-Si alloy will deteriorate.

It is also possible to replace part of the Fe with at least one of Co and Ni.

The saturation magnetic flux density can be increased by substituting a part of Fe for Co. In particular, 40 wt% of Fe is C
The maximum saturation magnetic flux density can be obtained by replacing with o. The substitution amount of Co is 0 to 60% by weight with respect to Fe.
It is preferably within the range.

By substituting a part of Fe for Ni, the magnetic permeability can be kept high without decreasing the saturation magnetic flux density. The substitution amount of Ni is 0 to Fe.
It is preferably in the range of 40% by weight.

Further, various elements may be added as an additive to the above Fe-Al-Si alloy in order to improve the corrosion resistance and the wear resistance. As the element used as the additive,
Group IIIa elements including lanthanum series such as Sc, Y, La, Ce, Nd and Gd, Group IVa elements such as Ti, Zr and Hf,
Va group elements such as V, Nb and Ta, and VI such as Cr, Mo and W
Group a elements, Group VIIa elements such as Mn, Tc, Re, Cu,
Ib group elements such as Ag and Au, Ga, In, Ge, Sn,
Sb etc. are mentioned.

By the way, although the ferromagnetic metal thin films (15) and (19) are formed as a single layer by the vacuum thin film forming technique in this example,
For example, SiO ₂ , Ta ₂ O ₅ , Al ₂ O ₃ , ZrO ₂ , Si ₃
A plurality of layers may be laminated through a high abrasion resistant insulating film such as N ₄ . In this case, the number of laminated ferromagnetic metal thin films can be set arbitrarily.

In addition, one of the magnetic core halves (21) and (22) is provided with a winding groove (20) in one of the magnetic core halves (22).
By winding a coil around (20), a signal is supplied to the magnetic head or a signal is taken out.

In the magnetic head having such a structure, the first inclined surfaces (13a) and (14a) near the magnetic gap g are formed so as to be 10 ° <θ ≦ 35 ° with the magnetic gap forming surface (16). Therefore, a magnetic head having a wide track width can be formed even if the ferromagnetic metal thin films (15) and (19) are thin. Therefore, productivity is significantly improved.

Further, as described above, the interface between the ferromagnetic oxide and the ferromagnetic metal thin film, that is, the first inclined surfaces (13a) and (14a) are formed at a predetermined angle with respect to the magnetic gap g, and therefore, they are adjacent to each other. Crosstalk from tracks or adjacent tracks is reduced, and the effects of pseudo gaps are also reduced.

Further, the ferromagnetic metal thin films (15) and (19) deposited on the magnetic core halves (21) and (22), which are ferromagnetic oxides, are the ferromagnetic metal thin film forming surfaces (13) and (14). ) At the bends (13c) and (14c),
Since stress caused by the difference in thermal expansion coefficient between the magnetic core parts (11) and (12) and the ferromagnetic metal thin films (15) and (19) is relaxed and dispersed, damage such as cracks may occur. It's gone.

Further, since the ferromagnetic thin film forming surfaces (13) and (14) have bent portions (13c) and (14c) formed by obtuse angles in the middle thereof, the volume occupied by the ferromagnetic oxide near the magnetic gap g. And the wear resistance is improved, and the contact area between the ferromagnetic metal thin films (15) and (19) and the magnetic core parts (11) and (12) is expanded to improve the recording / reproducing characteristics.

By the way, the present invention is not limited to the above-mentioned embodiments, and various other structures can be adopted without departing from the gist of the present invention.

For example, as shown in FIG. 3, track width regulating grooves (31a) and (32a) are formed so as to cut out a part of the first inclined surfaces (13a) and (14a) near the magnetic gap g. Is also good. With such a configuration, for example, one magnetic core half body (35)
Since a distance is secured between the ferromagnetic metal thin film (15) and the magnetic core portion (32) of the other magnetic core half body (36), the influence of crosstalk can be further reduced. In FIG. 3, the same members as those in FIGS. 1 and 2 are designated by the same reference numerals and detailed description thereof is omitted.

〔The invention's effect〕

As is clear from the above description, in the present invention,
Since the ferromagnetic metal thin film formation surface is composed of two inclined surfaces that are inclined at different angles with respect to the magnetic gap formation surface, the abutting width (track width) of the ferromagnetic metal thin film is set in the vicinity of the magnetic gap. Can be expanded. Therefore, for example, the film thickness of the ferromagnetic metal thin film for ensuring a predetermined track width can be thin, which is advantageous in terms of productivity.

Further, in the present invention, the inclination angle of each of the inclined surfaces is set to 10 ° <θ ≦ 35 ° near the magnetic gap, and the inclination angle far from the magnetic gap is set to 45 ° ≦ α ≦ 70 °. The influence of talk and pseudo gap can be suppressed. Therefore, good electromagnetic conversion characteristics can be obtained.

Furthermore, since an obtuse-angled bent portion is formed on the surface where the ferromagnetic metal thin film is formed, the strain caused by the difference in the coefficient of thermal expansion between the ferromagnetic metal thin film and the ferromagnetic oxide is dispersed and absorbed in this portion, and cracks are generated. The magnetic head has no cracks and is highly reliable.

Further, by forming the bent portion, the volume occupied by the ferromagnetic oxide in the vicinity of the magnetic gap is increased, the reproduction output is ensured, and the wear resistance is improved and the magnetic head has excellent reliability. .

[Brief description of 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 a main part enlarged plan view showing a contact surface of the magnetic recording medium. FIG. 3 shows another example of the present invention, which shows a magnetic recording medium contact surface of a magnetic head in which a part of a ferromagnetic metal thin film is cut out by a track width regulating groove in the vicinity of a magnetic gap. FIG. 11, 12 ...... Magnetic core 13, 14 ...... Ferromagnetic thin film forming surface 13a, 14a ...... First inclined surface 13b, 14b ...... Second inclined surface 15, 19 ...... Ferromagnetic metal thin film 16 ...... Magnetic gap forming surface 21,22 ... Magnetic core half

Claims (1)

[Claims] 1. A magnetic core half body is formed from a magnetic core portion made of a ferromagnetic oxide and a ferromagnetic metal thin film formed by a vacuum thin film forming technique on a ferromagnetic thin film forming surface of the magnetic core portion. A magnetic gap is formed by arranging ferromagnetic metal thin films to face each other in series, and the magnetic thin film forming surface and the magnetic gap forming surface are inclined at a predetermined angle on the contact surface of the magnetic recording medium. Where the ferromagnetic thin film forming surface is inclined near the magnetic gap at an angle θ of 10 ° <θ ≦ 35 ° with respect to the magnetic gap forming surface and 45 ° ≦ with respect to the magnetic gap forming surface.
A magnetic head comprising an inclined surface inclined at an angle α of α ≦ 70 °.