JPH0546911A - Magnetic head and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a product with excellent recording characteristic by using a core material made by laminating an Fe-Ta-N based soft magnetic film and an insulating film slternately to form a magnetic circuit. CONSTITUTION:A core material made by laminating a soft magnetic film 1 with a thickness of 1-10mum and an insulating film 2 made o f SiO, Al2O3 or the like alternately is arranged to form a magnetic circuit of a magnetic head. The soft magnetic film 1 herein used is an Fe-Ta-N based soft magnetic film with a composition having Fe main component and containing 5-17 atom % of N and 7-15 atom% of Ta only or an Fe-Ta-B-N based soft magnetic film with a composition having Fe as main component and containing 6-15 atom% of N, 7-15 atom% of Ta and 0.5-13 atom % of B. This film is made by a sputtering method with a target facing a substrate 3 parallel and a heat treatment in the manufacturing of a magnetic head is performed in a non-magnetic field. Thus, excellent recording characteristic is exhibited to a medium with a high coercive force to obtain a high reproduction efficiency in a high frequency area with smaller sliding noises in a high frequency.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In response to the recent demand for high density recording in the field of magnetic recording, development of a high performance magnetic head compatible with a high coercive force medium has been advanced. 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 nonmagnetic substrates 3 and the core material is used. A laminated head of the type in which a magnetic circuit is formed, or as shown in (FIG. 7),
A magnetic head (called a MIG head) has been developed in which the magnetic path is mostly composed of ferrite 5, and the soft magnetic film 7 is provided only in the vicinity of the magnetic gap 6 where magnetic saturation easily occurs. The laminated head has a
There is an advantage that there is no influence of the pseudo output, sliding noise at high frequency is small, and high reproduction efficiency can be obtained in a high frequency band.

Further, the characteristics of the magnetic head are closely related to the material characteristics of the core material used for the magnetic head. In order to achieve high density recording, the characteristics of the core material of the magnetic head are high saturation magnetic flux density. (Mainly affects recording characteristics) and high magnetic permeability (mainly affects reproduction characteristics) are required.

In response to such demands, sendust and Co which are practically used as the core material of the laminated head
The base amorphous alloy has a low saturation magnetic flux density of about 1 T,
Furthermore, 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 has been actively conducted. As one of them, 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 thermal stability of the soft magnetic properties.

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

[0007]

[Problems to be Solved by the Invention] 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, which is higher in order to obtain sufficient recording characteristics for a medium having a high coercive force. A core material having a saturation magnetic flux density is required.
In addition, this Co-Nb-Zr / Co-Nb-Zr-N composition modulation nitride film, like Sendust or Co-based amorphous alloy,
High magnetic permeability cannot be obtained by heat treatment in a magnetic field, and when it is used as the core material of the above-mentioned laminated head, isotropic high magnetic permeability characteristics are required for the core material. The above heat treatment is required, which causes a problem that the heat treatment apparatus becomes complicated.

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

[0009]

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

The Fe-Ta-N system or Fe-
The Ta-BN type soft magnetic film is a solid solution of at least one element or compound of Ta, N (nitrogen), B (boron), Ta nitride, and Ta boride, and the lattice is expanded. A material having a fine structure in which α-Fe fine crystals are mixed with Ta nitride fine particles or Ta boride fine particles, wherein the α-Fe fine crystals have an average particle size of 100 Å or less, Ta nitride fine particles or Ta fine particles It is assumed that the boride fine particles have a film structure having an average particle diameter of 50 Å or less.

[0011]

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

In particular, the Fe-Ta-N system or Fe-
When the Ta-BN based 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 in a non-magnetic field, a complicated device such as a heat treatment furnace in a magnetic field is not required, and mass production of magnetic heads becomes possible. In addition, the Fe-Ta-BN system soft magnetic film is F
Compared with 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 a higher heat treatment temperature, and glass bonding can be performed at high temperature when forming a magnetic head. This makes it possible to use glass that has a wider selection range of glass, has sufficient bonding strength, and requires high-temperature heat treatment that is excellent in wear resistance, and enhances the reliability of the magnetic head.

[0014]

【Example】

(Example 1) Fe-T was formed by an RF bipolar sputtering method, which is a sputtering method in which a target and a substrate face each other in parallel.
A Fe-Ta-N-based soft magnetic film is formed on a water-cooled non-magnetic ceramic substrate having a thermal expansion coefficient of 115 x 10 ^-7 / ° C by using an alloy target of a and introducing N ₂ gas into Ar gas. The film was formed in a thickness of 0.2 to 15 μm, and heat-treated at 550 ° C. for 1 hour in vacuum 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 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 prepared Fe-Ta-N film was Fe 76.5 at%, Ta 10.5 at%, and N 13 at% (hereinafter, Fe 76.5 at%, Ta 10. 5 atomic% and N13 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 film thickness and the coercive force Hc. From (Fig. 3), the film with a thickness of 1.5 μm or more is 8
It can be seen that it exhibits a low coercive force of A / m or less and has excellent soft magnetic characteristics. Then, Hc sharply increases on the low film thickness side when the film thickness is around 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 in the vicinity of the film thickness of 1.5 to 3 μm, sharply decreases in the low film thickness side and gradually decreases in the high film thickness side around the film thickness of 1.5 μm. Show. Then, as the frequency increases, there is a tendency that the decrease of μ ′ on the high film thickness side of 1.5 μm or more becomes large. When the film thickness is less than 1 μm, μ ′ in the 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, the μ ′ in the high frequency band of 5 MHz or more shows a low value of 1000 or less. It is not suitable as a magnetic head core material used in video tape recorders and the like. Therefore, an excellent head output is obtained when the film thickness of the soft magnetic film of each layer as the core material of the laminated head used in a video tape recorder or the like is 1 to 10 μm.

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

(Example 2) By the same RF bipolar sputtering method as in Example 1, Fe
-Ta and Fe-Ta-B alloy targets were used.
A thermal expansion coefficient of 115 × 10 was applied to a soft magnetic film (film thickness 2 μm) having a film composition in which N ₂ gas was introduced into r gas and B content in the film was different (Ta and N contents in the film were almost constant). ^-7 /
It was formed on a water-cooled non-magnetic ceramic substrate at ° C and the effect of B content in the film was examined. All the produced films are
1 in a temperature range of 300 to 700 ° C in a vacuum and no magnetic field
Heat treatment was performed for an hour. As a result of composition analysis, the composition of the formed film was Fe ₇₇ Ta ₁₁ N ₁₂ , Fe _78.5 Ta ₁₁ B _1.5 N ₉ ,
It was Fe ₇₆ Ta ₁₀ B ₅ N ₉ and Fe ₆₈ Ta ₁₁ B ₁₁ N ₁₀ .

The heat treatment temperature dependence of the coercive force Hc of these soft magnetic films is shown in FIG. As shown in FIG. 5, in the Fe-Ta-N soft magnetic film containing 0 atomic% of B in the film, the soft magnetic characteristics are deteriorated at the heat treatment temperature of about 550 ° C or higher, but the Fe-Ta containing B is contained. It can be seen that the -BN type soft magnetic film exhibits a low coercive force Hc (excellent soft magnetic property) even at a higher heat treatment temperature. As the B content in the film increases, the coercive force Hc decreases up to the high temperature heat treatment temperature.
The film having a B content of 5 atomic% exhibits excellent soft magnetism even at a heat treatment temperature of 700 ° C. These Fe-Ta-BN based soft magnetic films show a high soft magnetic flux with high saturation magnetic flux density (1.2 to 1.6T) and low magnetostriction (absolute value of 1 x 10 ^-6 or less). ) Had.

Therefore, the Fe-Ta-BN system 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 soft magnetic film.

It is to be noted that Fe is a main component, N is contained in an amount of 6 to 15 atom%, Ta is contained in an amount of 7 to 15 atom%, and B is in an amount of 0.5 to 1
The Fe-Ta-BN system soft magnetic film having a composition containing 3 atomic% had the same effect. N is 6 atomic% or less,
Ta is 7 atomic% or less, B is 0.5 atomic% or less, Fe is 8
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 ranges, the saturation magnetic flux density was reduced to 1 T or less due to the decrease in the Fe content in the film.

Further, the Fe-Ta-N system and the Fe-T system
The Cr element was added as an additive element to the a-B-N based soft magnetic film.
The core material added with 1 to 2 atomic% was able to have more excellent corrosion resistance as well.

(Example 3) By the same RF dipole sputtering method as in (Example 1), a Fe-Ta-N-based soft material was formed on a water-cooled non-magnetic ceramic substrate having a thermal expansion coefficient of 115 x 10 ^-7 / ° C. Magnetic film thickness 0.2
It was formed in a range of 15 μm, and heat treatment was performed at a temperature of 550 ° C. for 1 hour in vacuum without a magnetic field. Coefficient of thermal expansion 115
On the non-magnetic ceramic substrate water-cooled at × 10 ^-7 / ° C, Fe 76.5 atomic% and Ta described in (Example 1) were used.
Fe-Ta having a composition of 10.5 atomic% and N13 atomic%
A core material in which a -N-based soft magnetic film (thickness: 3 μm) and a SiO ₂ insulating film (thickness: 0.2 μm) are alternately laminated is prepared and subjected to a magnetic head processing heat treatment step in a non-magnetic field (see FIG. 6). The laminated head shown in FIG. The manufactured magnetic head had a track width of 11 μm, a gap length of 0.23 μm, a gap depth of 22 μm, and a coil winding number of 20 turns. The head output was measured using an endless head tester and a drum tester, and a coercive force of 119400 A / m was measured.
Using P-tape, relative velocity 7m / s and 21m / s
The self-recording / reproducing characteristic at s was measured. Relative speed 7 (Fig. 1)
In the case of m / s, (FIG. 2) shows the frequency characteristics of the head output standardized by the track width and the number of turns when recording with the optimum recording current at each frequency when the relative speed is 21 m / s. For comparison, Co-Nb-Ta is 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. 2). From (FIG. 1) and (FIG. 2), Fe
-Ta-N-based soft magnetic film and SiO ₂ insulating film are alternately laminated, and the laminated head using the core material is Co-Nb-Ta.
-Compared to a laminated head using a core material in which Zr amorphous films and SiO ₂ insulating films are alternately laminated, high output characteristics are exhibited at long wavelengths and equivalent good characteristics at short wavelengths. There is. In this embodiment, the coercive force 119 currently on the market is used.
Although the self-recording / reproducing characteristic was shown when the MP tape of 400 A / m was used, the magnetic head of the present invention showed a more excellent self-recording / reproducing characteristic for a medium having a higher coercive force and a high density. A record can be achieved.

In the present embodiment, the magnetic circuit is composed of a core material in which a 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. The laminated magnetic head in which the Fe-Ta-N-based soft magnetic film of each layer of the core material is formed has a thickness of 1 to 10 μm.
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 Fe 76.5 at%, Ta 10.5 at%, and N 13 at% was described. 5 to 17 atomic% and Ta of 7-1
The Fe-Ta-N based soft magnetic film having a composition containing 5 atomic% also had the same effect.

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

Further, the Fe-Ta-N system and Fe-T
The film structure of the a-B-N based soft magnetic film was examined by X-ray diffraction and a transmission electron microscope (TEM). As a result, Ta, N
(Nitrogen), B (boron), Ta nitride, Ta boride at least one element or a compound or a solid solution thereof, and the lattice expansion of α-Fe microcrystals and Ta nitride fine particles or A material having a fine structure in which Ta boride fine particles are mixed, wherein the α-Fe microcrystals have an average particle size of 100 Å or less, and Ta nitride fine particles or Ta boride fine particles have an average particle size of 50 Å or less. Particularly excellent magnetic head output was obtained.

The core material in this embodiment is RF.
Although it was produced by the bipolar sputtering method, the method for producing the core material of the present invention is not limited to the RF bipolar sputtering method.
Similar effects were obtained in a sputtering method such as a two-pole, three-pole, magnetron method using a direct current or a high frequency, and a method in which a target and a substrate face each other in parallel such as a bias sputtering method. However, in the facing target sputtering method, in which the target and the substrate are not arranged in parallel, or the ion beam sputtering method, atoms flying obliquely from the target are attached to the substrate, so the magnetic permeability characteristics of the formed film differ. There was a direction. 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, the Fe-Ta-N-based or Fe-Ta-BN-based soft magnetic film and insulating film having a specific composition range, a specific film structure, and a specific film thickness. A magnetic head in which a magnetic circuit is formed by manufacturing a core material in which the and are alternately laminated by a sputtering method in which a target and a substrate face each other in parallel, and the heat treatment in the manufacturing process is performed in a non-magnetic field. Therefore, the recording characteristics are excellent for a high coercive force medium, sliding noise at high frequencies is small, and high reproduction efficiency can be realized in the high frequency band. Further, since the magnetic head can be manufactured by a simple heat treatment in a magnetic field-free, a complicated device such as a heat treatment furnace in a magnetic field is not required, and mass production of magnetic heads becomes possible. Further, in a magnetic head in which a magnetic circuit is formed of a core material in which an Fe-Ta-B-N-based soft magnetic film and an insulating film are alternately laminated, the magnetic head is formed by using the Fe-Ta-N-based soft magnetic film as the core material. Compared with the above, it is possible to join glass at a higher heat treatment temperature, and it is possible to use glass that has sufficient glass strength and requires high-temperature heat treatment with excellent wear resistance characteristics, and to improve the reliability of the magnetic head. Can be done.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship of head output with respect to 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 the head output and the frequency at a relative speed of 21 m / s of the magnetic head manufactured in the example of the present invention.

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

FIG. 4 is a diagram showing a relationship between a film thickness of a soft magnetic film and a 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 conventional 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)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Ken Takahashi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. A magnetic head in which a magnetic circuit is formed of a core material in which Fe—Ta—N-based soft magnetic films and insulating films are alternately laminated, wherein the soft magnetic film contains Fe as a main component and N 5-
A magnetic head having a composition containing 17 atomic% and 7 to 15 atomic% Ta. 2. A magnetic head in which a magnetic circuit is formed of a core material in which an Fe—Ta—B—N-based soft magnetic film and an insulating film are alternately laminated, the soft magnetic film containing Fe as a main component, A magnetic head having a composition containing 6 to 15 atomic% of N, 7 to 15 atomic% of Ta, and 0.5 to 13 atomic% of B. 3. The soft magnetic film according to claim 1 is Ta, N
(Nitrogen), at least one element of Ta nitride,
Alternatively, it is a material having a fine structure in which a compound is dissolved as a solid solution and the lattice expansion of α-Fe fine crystals and Ta nitride fine particles are mixed, and the average grain size of the α-Fe fine crystals is 100.
A magnetic head characterized in that the average particle diameter of the Ta nitride fine particles is Å or less and 50 Å or less. 4. The soft magnetic film according to claim 2, wherein Ta, N
(Nitrogen), B (boron), Ta nitride, Ta boride at least one element or a compound or a solid solution thereof, and the lattice expansion of α-Fe microcrystals and Ta nitride fine particles or , A material having a fine structure in which fine particles of boride of Ta are mixed, wherein the average grain size of the α-Fe microcrystals is 100 Å or less, and the average grain size of nitride fine particles of Ta or Ta boride fine particles is 50 Å or less. A magnetic head characterized in that 5. The soft magnetic film of each layer of the core material according to claim 1 has a film thickness of 1 to 10 μm, and the insulating film of each layer has a film thickness of 0.05 to 0.5 μm. The magnetic head is characterized in that the soft magnetic film is formed on the surface of the substrate by a sputtering method in which the target and the substrate face each other in parallel, and the heat treatment in the magnetic head processing step is performed in a non-magnetic field. Method.