JP2782994B2 - Manufacturing method of magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a magnetic recording and reproducing apparatus (V
TR), a magnetic recording / reproducing device, a magnetic head used in a magnetic recording / reproducing device such as a magnetic recording device for a computer, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In response to recent demands for high-density recording in the field of magnetic recording, the development of high-performance magnetic heads compatible with high coercive force media has been promoted. In such a magnetic head, as shown in FIG. 6, a core material in which a soft magnetic film 1 and an insulating film 2 are alternately laminated in the track width direction is sandwiched between non-magnetic substrates 3. A laminated type head in which a magnetic circuit is formed, or as shown in FIG.
A magnetic head (referred to as a MIG head) has been developed in which a magnetic path is mostly formed of ferrite 5 and a soft magnetic film 7 is provided only in the vicinity of a magnetic gap 6 that is easily magnetically saturated. The laminated type head is compared with the MIG head,
There is an advantage that there is no influence of pseudo output, sliding noise at high frequency is small, and high reproduction efficiency can be obtained in a high frequency band.

[0003] The characteristics of the magnetic head are closely related to the material characteristics of the core material used in the magnetic head. To achieve high-density recording, the characteristics of the core material of the magnetic head must be high saturation magnetic flux density. (Mainly affecting recording characteristics) and high magnetic permeability (mainly affecting reproduction characteristics) are required.

[0004] In response to such demands, Sendust and Co have been put to practical use as core materials for the laminated type head.
In the base amorphous alloy, the saturation magnetic flux density is as low as about 1T,
Further, in order to realize high-density recording, these conventional materials have a limit in saturation magnetic flux density.

Therefore, research and development of a soft magnetic film having a high saturation magnetic flux density and a high magnetic permeability have been actively conducted. As one of them, an Fe—N film has been studied. However, this Fe—N film has not been put to practical use because its soft magnetic properties are rapidly deteriorated by heat treatment at 350 ° C. or higher, and there is a problem in the thermal stability of the soft magnetic properties.

On the other hand, Co-Nb- has been proposed as a material having improved thermal stability of soft magnetism and saturation magnetic flux density of a Co-based amorphous alloy.
Zr / Co-Nb-Zr-N composition modulation nitride film was developed,
A multilayer head is manufactured (Journal of the Japan Society of Applied Magnetics)
Vol.14 No.2).

[0007]

However, this Co-
Even in the Nb-Zr / Co-Nb-Zr-N composition modulation nitride film, the saturation magnetic flux density is at most 1.3 T, and in order to obtain sufficient recording characteristics with respect to a medium having a high coercive force, a higher value is required. A core material having a saturation magnetic flux density is required.
Further, this Co-Nb-Zr / Co-Nb-Zr-N composition modulation nitride film is, like Sendust or Co-based amorphous alloy,
When high magnetic permeability cannot be obtained by heat treatment in the absence of a magnetic field and is used as the core material of the above-mentioned multilayer head, the core material is required to have an isotropic high magnetic permeability characteristic. Heat treatment is required, and the heat treatment apparatus becomes complicated.

The present invention relates to an Fe—Ta— film having a specific composition range, a specific film structure, and a specific film thickness, which is produced by a sputtering method in which a target and a substrate face in parallel.
Based on the discovery that N-based or Fe-Ta-BN-based soft magnetic films have isotropic high permeability characteristics with high saturation magnetic flux density and low magnetostriction even in a simple heat treatment in the absence of a magnetic field. It is an object of the present invention to provide a laminated magnetic head which solves the above-mentioned problems.

[0009]

A soft magnetic film having a thickness of 1 to 10 μm and an insulating film such as SiO ₂ and Al ₂ O ₃ having a thickness of 0.05 to 0.5 μm are alternately provided. The magnetic circuit of the magnetic head is formed from the laminated core materials. The soft magnetic film is F
e as a main component, N is 5 to 17 atomic%, and Ta is 7 to 15
Fe-Ta-N-based soft magnetic film having a composition containing at.% Or Fe as a main component, 6 to 15 at.% Of N, and 7 to.
An Fe-Ta-BN soft magnetic film having a composition containing 15 atomic% and B in an amount of 0.5 to 13 atomic% is formed by a sputtering method in which a target and a substrate are opposed in parallel. The heat treatment in the magnetic head processing step is performed in the absence of a magnetic field.

In addition, the above-mentioned Fe—Ta—N system or Fe—Ta—N
The Ta-BN-based soft magnetic film solid-dissolves at least one element or compound of Ta, N (nitrogen), B (boron), nitride of Ta, and boride of Ta, and the lattice expands. A material having a microstructure in which α-Fe microcrystals and Ta nitride fine particles or Ta boride fine particles are mixed, and the average particle size of the α-Fe microcrystals is 100 ° or less, and Ta nitride fine particles or Ta Has a film structure in which the average particle size of the boride fine particles is 50 ° or less.

[0011]

The magnetic head according to the present invention uses a soft magnetic film exhibiting a high saturation magnetic flux density and a low magnetostriction and isotropic high magnetic permeability in a heat treatment in the absence of a magnetic field. On the other hand, it exhibits excellent recording characteristics, has low sliding noise at high frequencies, and can achieve high reproduction efficiency in a high frequency band.

In particular, the Fe—Ta—N system or the Fe—Ta—N
When the Ta-BN soft magnetic film has the above film structure, excellent magnetic head characteristics can be obtained.

Further, since the magnetic head can be manufactured by a simple heat treatment without a magnetic field, a complicated apparatus such as a magnetic field heat treatment furnace is not required, and mass production of the magnetic head becomes possible. Further, the Fe-Ta-BN soft magnetic film is made of F
Compared to the e-Ta-N based soft magnetic film, it is possible to realize good soft magnetism with high saturation magnetic flux density and low magnetostriction at higher heat treatment temperature, and to form glass head at high temperature when forming a magnetic head. This makes it possible to use glass requiring a high-temperature heat treatment, which has a wide selection range of glass, has sufficient bonding strength, and is excellent in abrasion resistance, and can improve the reliability of the magnetic head.

[0014]

【Example】

(Example 1) Fe-T was formed by RF bipolar sputtering, which is a sputtering method in which a target and a substrate faced in parallel.
A Fe—Ta—N-based soft magnetic film is formed on a water-cooled nonmagnetic ceramics substrate having a thermal expansion coefficient of 115 × 10 ⁻⁷ / ° C. by introducing N ₂ gas into Ar gas using the alloy target a. The film was formed in a thickness of 0.2 to 15 μm, and was subjected to a heat treatment at a temperature of 550 ° C. for 1 hour in a vacuum and without a magnetic field. The coercive force Hc of these films and the real part μ ′ of the complex magnetic permeability at each frequency were measured. As a result, the coercive force Hc and the magnetic permeability μ ′ of these films were all isotropic in the film plane. As a result of RBS (Rutherford backscattering) analysis, the composition of the produced Fe-Ta-N film was Fe 76.5 atomic%, Ta 10.5 atomic%, and N 13 atomic% (hereinafter, Fe 76.5 atomic%, Ta 10. 5 atomic% and N 13 atomic% are Fe _76.5 T
a _10.5 N ₁₃ ). The saturation magnetic flux density of these films is about 1.6 T, and the saturation magnetostriction is 1 × 1 in absolute value.
It was 0 ^-6.

FIG. 3 shows the relationship between the coercive force Hc and the film thickness. According to FIG. 3, a film having a thickness of 1.5 μm or more has a thickness of 8 μm.
It shows that it has a low coercive force of A / m or less and has excellent soft magnetic properties. Then, Hc sharply increases on the lower film thickness side around the film thickness of about 1.5 μm. FIG. 4 shows the relationship between the magnetic permeability μ ′ and the film thickness. Μ ′ at 1 MHz shows a maximum value near the film thickness of 1.5 to 3 μm, rapidly decreases at the low film thickness side near the film thickness of 1.5 μm, and gradually decreases at the high film thickness side. Show. Then, as the frequency increases, the decrease in μ ′ on the high film thickness side of 1.5 μm or more tends to increase. When the film thickness is less than 1 μm, μ ′ in a high frequency band of 1 MHz or more shows a low value of 1000 or less, and when the film thickness is 10 μm or more, μ ′ in a high frequency band of 5 MHz or more has a low value of 1000 or less. However, it is not suitable as a magnetic head core material used for a video tape recorder or the like. Therefore, when the thickness of the soft magnetic film of each layer as the core material of the laminated type head used in a video tape recorder or the like is 1 to 10 μm, an excellent head output can be obtained.

In this embodiment, the Fe—Ta—N soft magnetic film having a composition of 76.5 atomic% of Fe, 10.5 atomic% of Ta, and 13 atomic% of N has been described. 5 to 17 atomic% and Ta is 7-1.
The same effect was obtained in the Fe-Ta-N-based soft magnetic film having a composition containing 5 atomic%. N is 5 atomic% or less, Ta
In a composition range of 7 atomic% or less and Fe of 88 atomic% or more, good soft magnetic characteristics could not be obtained at any film thickness. Further, in a composition range in which N is 17 atomic% or more, Ta is 15 atomic% or more, and Fe is 68 atomic% or less, F
Due to the decrease in the e content, the saturation magnetic flux density was reduced to 1T or less.

(Embodiment 2) By the same RF bipolar sputtering method as in (Embodiment 1), Fe
Using an alloy target of -Ta and Fe-Ta-B, A
An N ₂ gas was introduced into the r gas, and a soft magnetic film (thickness: 2 μm) having a film composition with a different B content (Ta and N contents in the film was almost constant) was thermally expanded to 115 × 10 5 ^-7 /
The film was formed on a water-cooled nonmagnetic ceramic substrate of ゜ C, and the effect of the B content in the film was examined. All the fabricated films are
1 in a temperature range of 300 to 700 ° C in a vacuum and no magnetic field
Time heat treatment was performed. As a result of the composition analysis, the composition of the formed film was determined to be Fe ₇₇ Ta ₁₁ N ₁₂ , Fe _78.5 Ta ₁₁ B _1.5 N ₉ ,
Fe ₇₆ Ta ₁₀ B ₅ N ₉ and Fe ₆₈ Ta ₁₁ B ₁₁ N ₁₀ .

FIG. 5 shows the heat treatment temperature dependence of the coercive force Hc of these soft magnetic films. From FIG. 5, in the Fe—Ta—N based soft magnetic film having a B content of 0 atomic%, the soft magnetic characteristics are deteriorated at a heat treatment temperature of about 550 ° C. or more, but the Fe—Ta containing B is It can be seen that the -BN-based soft magnetic film shows a low coercive force Hc (excellent soft magnetic properties) even at a higher heat treatment temperature. Then, as the B content in the film increases, the coercive force Hc decreases until the heat treatment temperature reaches a high temperature.
The film having a B content of 5 atomic% shows good soft magnetism even at a heat treatment temperature of 700 ° C. These Fe-Ta-BN soft magnetic films have high saturation magnetic flux density (1.2 to 1.6 T) and low magnetostriction (1 × 10 ^-6 or less in absolute value) by high-temperature heat treatment showing good soft magnetism. ).

Accordingly, the Fe—Ta—BN soft magnetic film is
It can be used as a magnetic head core material at a heat treatment temperature higher than that of the Fe-Ta-N-based soft magnetic film.

It should be noted that Fe is a main component, N is 6 to 15 atomic%, Ta is 7 to 15 atomic%, and B is 0.5 to 1 atomic%.
The same effect was obtained in the Fe-Ta-BN soft magnetic film having a composition containing 3 atomic%. N is 6 atomic% or less,
Ta is 7 at% or less, B is 0.5 at% or less, Fe is 8 at%.
In the composition range of 6.5 atomic% or more, good soft magnetic characteristics could not be obtained. Further, N is 15 atomic% or more, and Ta is 1
5 atomic% or more, B 13 atomic% or more, Fe 57 atomic%
In the following composition range, the saturation magnetic flux density was reduced to 1 T or less due to a decrease in the Fe content in the film.

In addition, the above-mentioned Fe—Ta—N system and Fe—T
The Cr element as an additive element is added to the a-B-N-based soft magnetic film in an amount of 0.1%.
The core material to which 1 to 2 atomic% was added was able to have more excellent corrosion resistance.

(Embodiment 3) An Fe-Ta-N-based soft magnetic material was deposited on a water-cooled non-magnetic ceramic substrate having a thermal expansion coefficient of 115 × 10 ^-7 / ° C by the same RF bipolar sputtering method as in (Embodiment 1). When the magnetic film is
A heat treatment was performed at a temperature of 550 ° C. for 1 hour in a vacuum and without a magnetic field. Thermal expansion coefficient 115
On a water-cooled nonmagnetic ceramic substrate of × 10 ^-7 / ° C, 76.5 atomic% of Fe and Ta described in (Example 1)
Fe-Ta having a composition of 10.5 atomic% and N 13 atomic%
-N based soft magnetic film (thickness 3 μm) and SiO ₂ insulating film (thickness 0.2 μm) were alternately laminated to produce a core material. ) Was manufactured. The track width of the manufactured magnetic head was 11 μm, the gap length was 0.23 μm, the gap depth was 22 μm, and the number of coil turns was 20 turns. The head output was measured using an endless head tester and a drum tester.
Using P tape, relative speeds of 7 m / s and 21 m / s
s was measured. (Fig. 1) with relative speed 7
FIG. 2 shows the frequency characteristics of the head output normalized by the track width and the number of windings when recording with the optimum recording current at each frequency when the relative speed is 21 m / s when the speed is m / s (FIG. 2). For comparison, Co-Nb-Ta was used as the soft magnetic film.
The frequency characteristics of the standardized head output of the laminated head manufactured in the same shape using the -Zr amorphous film are also shown in FIG. 1 and FIG. From FIG. 1 and FIG.
-Ta-N system and a soft magnetic film, laminated head using the core material of alternately laminated SiO ₂ insulating film, Co-Nb-Ta
Compared with a stacked head using a core material in which a -Zr amorphous film and an SiO ₂ insulating film are alternately stacked, a high output characteristic is exhibited at a long wavelength, and the same good characteristic is exhibited at a short wavelength. I have. In the present embodiment, the coercive force 119 currently on the market is used.
Although the self-recording / reproducing characteristics when using an MP tape of 400 A / m were shown, the magnetic head of the present invention showed more excellent self-recording / reproducing characteristics for a medium having a higher coercive force, A record can be achieved.

In this embodiment, the magnetic circuit is made of a core material in which an Fe—Ta—N based soft magnetic film having a thickness of 3 μm and a SiO ₂ insulating film having a thickness of 0.2 μm are alternately laminated. Has been described, the thickness of the Fe—Ta—N based soft magnetic film of each layer of the core material is 1 to 10 μm.
m, the same effect was obtained when the thickness of the insulating film of each layer was 0.05 to 0.5 μm.

In the present embodiment, the Fe—Ta—N soft magnetic film having the composition of 76.5 atomic% of Fe, 10.5 atomic% of Ta, and 13 atomic% of N has been described. 5 to 17 atomic% and Ta is 7-1.
The same effect was obtained in the Fe-Ta-N-based soft magnetic film having a composition containing 5 atomic%.

Further, Fe is a main component, N is 6 to 15 atomic%, Ta is 7 to 15 atomic%, and B is 0.5 to 1 atomic%.
The Fe-Ta-BN soft magnetic film having a composition containing 3 atomic% has the same effect and has the same effect as Fe-Ta-N.
Compared with the system soft magnetic film, it is possible to realize good soft magnetism with high saturation magnetic flux density and low magnetostriction at higher heat treatment temperature,
When forming a magnetic head, glass bonding can be performed at high temperature, the selection range of glass can be expanded, bonding strength is sufficient, and glass requiring high temperature heat treatment with excellent wear resistance can be used. Was able to increase the reliability.

[0026]

The core material in this embodiment is RF
Although it was produced by the bipolar sputtering method, the method of producing the core material of the present invention is not limited to the RF bipolar sputtering method.
The same effect was obtained in a sputtering method in which a target and a substrate faced in parallel, such as a two-pole, three-pole, magnetron method, and a bias sputtering method using direct current or high frequency. However, in the facing target sputtering method or the ion beam sputtering method in which the target and the substrate are not arranged in parallel, atoms flying obliquely from the target adhere to the substrate, so that the magnetic permeability characteristics of the formed film are different. Anisotropy occurred. As a result, the laminated magnetic head manufactured using the core material formed by these methods could not obtain good output characteristics.

[0028]

According to the present invention, an Fe--Ta--N or Fe--Ta--BN soft magnetic film having a specific composition range, a specific film structure, and a specific film thickness, and an insulating film A magnetic head is formed by forming a magnetic circuit by sputtering a core material in which a target and a substrate are opposed to each other in parallel, and the heat treatment in the manufacturing process is performed in the absence of a magnetic field. Therefore, the recording medium exhibits excellent recording characteristics with respect to a high coercive force medium, has low sliding noise at high frequencies, and can achieve high reproduction efficiency in a high frequency band. Further, since the magnetic head can be manufactured by a simple heat treatment in a magnetic field-free state, a complicated apparatus such as a magnetic field heat treatment furnace is not required, and mass production of the magnetic head becomes possible. In addition, a magnetic head in which a magnetic circuit is formed of a core material in which an Fe-Ta-BN soft magnetic film and an insulating film are alternately laminated has a structure in which an Fe-Ta-N soft magnetic film is used as a core material. Glass can be bonded at a higher heat treatment temperature than that required, and glass that has sufficient glass strength and requires high-temperature heat treatment with excellent wear resistance can be used to increase the reliability of the magnetic head. Can be done.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between head output and frequency at a relative speed of 7 m / s of a magnetic head manufactured in an example of the present invention.

FIG. 2 is a diagram showing the relationship between head output and frequency at a relative speed of 21 m / s of a magnetic head manufactured in an example of the present invention.

FIG. 3 is a diagram showing the relationship between the thickness of a soft magnetic film and the coercive force Hc manufactured in an example of the present invention.

FIG. 4 is a diagram showing the relationship between the thickness of a soft magnetic film and the real part μ ′ of complex magnetic permeability.

FIG. 5 is a diagram showing a relationship between a coercive force Hc of a soft magnetic film and a heat treatment temperature.

FIG. 6 is a schematic view of a conventionally provided laminated head.

FIG. 7 is a schematic view of a conventionally provided MIG head.

[Explanation of symbols]

 1, 7 Soft magnetic film 2 Insulating film 3 Non-magnetic substrate 4 Non-magnetic material (glass) 5 Ferrite 6 Magnetic gap 8 Non-magnetic material (glass)

Continuing on the front page (72) Inventor Ken Takahashi 1006 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. 56) References JP-A-2-290004 (JP, A) JP-A-2-275605 (JP, A) JP-A-63-254708 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , (DB name) G11B 5/127 G11B 5/147

Claims (2)

(57) [Claims] 1. An Fe—Ta—N-based soft magnetic film and an insulating film
A magnetic circuit is formed by alternately laminated core materials, and
When the magnetic film is mainly composed of Fe and contains 5 to 17 atomic% of N,
Magnetic heads both having a composition containing 7 to 15 atomic% of Ta
In the above , the thickness of the soft magnetic film of each layer of the core material is 1 to 10 μm,
The thickness of the insulating film of each layer is 0.05 to 0.5 μm;
Sputtering method with two targets and substrate facing in parallel
The soft magnetic film is formed on the substrate surface by
The feature is that the heat treatment in the doping process is performed in the absence of magnetic field
A method of manufacturing a magnetic head. 2. An Fe-Ta-BN soft magnetic film and an insulating film
A magnetic circuit is formed of a core material in which
The soft magnetic film has Fe as a main component, N at 6 to 15 atomic%,
Containing 7 to 15 atom% of Ta and 0.5 to 13 atom of B
% , The soft magnetic film of each layer of the core material has a thickness of 1 to 10 μm,
The thickness of the insulating film of each layer is 0.05 to 0.5 μm;
Sputtering method with two targets and substrate facing in parallel
The soft magnetic film is formed on the substrate surface by
The feature is that the heat treatment in the doping process is performed in the absence of magnetic field
A method of manufacturing a magnetic head.