JPH05174326A - Magnetic head - Google Patents

Abstract

PURPOSE:To improve the adhesive power between soft magnetic alloy films and magnetic cores. CONSTITUTION:Fe-Al-Si films 4 and the Fe-Al-Si soft magnetic films are alternately laminated with the soft magnetic alloy films 5 of different kinds from the Fe-Al-Si soft magnetic material films by each one layer in the state of the Fe-Al-Si soft magnetic films held in contact with oxide magnetic materials respectively on the opposite surfaces of a pair of the magnetic core half bodies of the magnetic head constituted by disposing a pair of the magnetic core half bodies formed with the oxide magnetic materials to face each other via a magnetic gap G. As a result, the electromagnetic conversion characteristics of the conventional magnetic head are maintained and the adhesive power of the soft magnetic alloy films to the magnetic cores is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used for recording / reproduction corresponding to a high coercive force magnetic recording medium such as a metal tape.

[0002]

2. Description of the Related Art In a magnetic recording / reproducing apparatus such as a VTR, high density recording has been advanced along with the shortening of the wavelength of an information signal for the purpose of high image quality.

In order to deal with this, a high coercive force magnetic recording medium such as a metal tape or a vapor deposition tape in which a ferromagnetic metal material is directly adhered to a base film is used, and a high coercive force is also used in the field of a magnetic head. Various magnetic heads using a soft magnetic alloy film as a magnetic core have been developed as magnetic heads suitable for magnetic recording media.

As an example of such a magnetic head, one having a structure as shown in FIGS. 12 and 13 is generally known. This type of magnetic head is usually called a parallel MIG (metal in gap) head, and as shown in FIG. 12, magnetic core halves (1), (2) made of an oxide magnetic material such as Mn—Zn ferrite. The soft magnetic alloy films (5) and (5) are provided on the abutting surface of (1) by means of sputtering or the like, and the magnetic core halves (1) and (2) are welded by the welded glass (6). Since this magnetic head is formed of the soft magnetic alloy film (5) in the vicinity of the magnetic gap (G), the strength of the magnetic field generated from the magnetic gap becomes large and it is suitable for a high coercive force magnetic recording medium.

The present applicant has proposed this type of magnetic head in Japanese Patent Application Laid-Open No. 3-131006 and Japanese Patent Application No. 3-186789 filed on July 1, 1991. The former is Fe _x M _z C, F as the soft magnetic alloy film (5).
e _x T _y M _z C _w are those with the latter Fe _x L _y B _z C _w as the soft magnetic alloy _{film, (Fe 1-a T a} ) x L
_y B _z C _w is used. In the composition, M is Ti, Zr, Hf, Nb, Ta, Mo, W, or a metal element composed of two or more thereof, or a mixture thereof, and T is one of Co and Ni, or Metal element consisting of two or more kinds or a mixture thereof, L is Zr, Hf, Ta, Nb
Among them, it is one or more elements.

[0006]

Since the recording / reproducing characteristics of the above magnetic head are greatly influenced by the magnetic characteristics of the soft magnetic alloy film (5) used, a high saturation magnetic flux density and a high magnetic permeability are combined. Development of the soft magnetic alloy film has been actively conducted in recent years.

However, the manufacture of a normal magnetic core is shown in FIG.
4, the track width (Tw), the core width (Cw),
And the first magnetic material bar (8) and the second magnetic material bar (10) in which the cutting margin (Sw) is continuously formed, are glass-welded by the fused glass (6), and the cutting margin is set after the glass welding. The cutting is performed by using a cutting device such as a dicer.

For this reason, when the above-mentioned fused glass (6) is used for joining, the first and second magnetic bars (8), (1) are used.
0) and the soft magnetic alloy film (5) have a difference in coefficient of thermal expansion, stress concentrates on the interface.

In the cutting of the core after glass welding, the soft magnetic alloy film (5) is peeled from the magnetic core halves (1) and (2) during cutting due to the concentration of stress and the force applied during cutting. A problem, or a problem that the soft magnetic alloy film (5) is partially missing or damaged during cutting, which not only causes a reduction in yield, but also causes peeling of the soft magnetic alloy film (5) or soft magnetic property during cutting. There is a problem that the adhesive strength of the soft magnetic alloy film (5) is lowered and the running reliability is lowered even if the alloy film (5) is not partially lost or damaged.

Further, when the soft magnetic alloy film disclosed in Japanese Patent Application Laid-Open No. 3-131006 and Japanese Patent Application No. 3-186789 proposed by the applicant in the past is used as an MIG head, film peeling and film formation are similarly performed. Of partial damage to the yield and decrease in yield and ferrite and soft magnetic alloy films (5)
There is a problem that a pseudo gap of 2 dB or more is detected at the interface with the.

The present invention has been proposed in order to solve the above-mentioned problems, and aims to improve the adhesive force of the soft magnetic alloy film, improve the yield and the bending strength, and have excellent reliability. It is intended to provide a magnetic head.

[0012]

In order to solve the above problems, the present invention provides a magnetic head in which a pair of magnetic core halves made of an oxide magnetic material are opposed to each other through a magnetic gap. Fe-Al-Si based soft magnetic film is in contact with the oxide magnetic material on the opposite surfaces of the magnetic core halves, respectively.
The e-Al-Si soft magnetic film is a magnetic head in which at least one soft magnetic alloy film of a different type is alternately laminated.

[0013]

With the Fe-Al-Si soft magnetic film (hereinafter referred to as the sendust film) in contact with the magnetic core half made of the oxide magnetic material as described above, the sendust film and the sendust film are made of different soft materials. By alternately laminating the magnetic alloy films, the adhesive force between the soft magnetic alloy film and the sendust film and the magnetic core half body is improved.

Therefore, in the step of cutting the core after the glass is welded, peeling of the film, partial damage and loss of the film are prevented, the yield is improved, and the bending strength of the manufactured core is improved and the running reliability is improved. To do. Also, by preventing film peeling, partial damage and loss of the film, damage to the film is reduced, and the ventilation differential electromotive force generated in the gap between the film and the oxide magnetic material is removed, so that environmental resistance is improved. improves

[0015]

EXAMPLES Examples of the present invention will be described in detail below.

1 and 2 are a perspective view and a top view showing the structure of a magnetic head used in an embodiment of the present invention. Reference numerals (1) and (2) are magnetic core halves made of an oxide magnetic material such as Mn-Zn ferrite, and a sendust film (4) and the soft magnetic alloy film (5) are provided on respective gap facing surfaces (3). ), Fe-MC system, Fe-T-, which will be described later.
MC system, Fe-LBC system and (FeT) -LB
A soft magnetic alloy film (5) made of —C-based or the like is laminated in this order. The magnetic core halves (1) and (2) are welded by welding glass (6) and (6) to form a magnetic core. Reference numeral (7) is a winding window, and a winding (not shown) is wound through the winding window (7).

Next, a method of manufacturing the magnetic head of the present invention will be described with reference to FIGS. In FIG. 3, reference numeral (8) is a first magnetic bar made of Mn-Zn ferrite or the like, and the first magnetic bar (8) has a groove (9) into which the welded glass is poured when the glass is welded. Are provided by means such as machining. As shown in FIG. 4, a laminated film is formed on the first magnetic bar (8) thus formed by a method such as sputtering in order of the sendust film (4) and the soft magnetic alloy film (5). To form. The thickness of each of the sendust film (4) and the soft magnetic alloy film (5) is preferably 0.2 to 10.0 μm.
m. The first magnetic material bar (8) processed as described above is the second magnetic material bar (1) similarly prepared.
0) and as shown in FIG. 5 are abutted against each other and welded by a welded glass (6) to continuously form a track width (Tw) core width (Cw) and a cutting margin (Sw). Form the body (11).

The magnetic bar-bonded body (11) thus formed is cut with a cutting device such as a dicer after the glass welding to cut the cutting margin (Sw), and the magnetic head as shown in FIGS. 1 and 2. Is formed.

Next, examples in which the soft magnetic alloy film (5) is variously modified will be compared with each other. Sendust film (4)
The film thickness of the soft magnetic alloy film (5) is 1 in this embodiment, respectively.
μm and 5 μm, and the film formation was performed by RF conventional. The temperature at the time of glass welding is 570 ° C., and the self-recording / reproducing output of the magnetic head uses a metal tape of Hc = 1500 Oe, a relative speed of 3.75 m / s, and a frequency of 5 MH
It was evaluated by z. The track width is 21 μm, the gap depth is 18 μm, the gap length is 0.22 μm, and the inductance is 1.1 μH. Comparative examples are first and second
The soft magnetic alloy film (5) is formed on the magnetic bars (8) and (10) of 6 μm in thickness, and the other conditions are the same as those in the present embodiment. Table 1 shows a comparison between the comparative example and this example.

[0020]

[Table 1] In Table 1 above, the output of Comparative Example 1 was standardized to 0 dB, and the number of locations where film peeling had occurred in Comparative Example 1 was 100% in the film peeling locations. Comparing the example and the comparative example, the self-recording / reproducing output is reduced by about ± 0 to −0.5 dB, but is higher by 2 to 3 dB than the Co-based amorphous alloy in the comparative example 2, which is practical. There is no problem. Further, it can be seen that the film peeling portion shows a remarkably good value of 6%. Further, film peeling at the interface between the soft magnetic alloy film (5) and the sendust film (4) was 0%. This indicates that the adhesion of the film is improved, and it can be seen that the magnetic head according to the present invention has excellent running reliability and environmental resistance.

In the present invention, the shape of the magnetic head is not limited to those shown in FIGS. 1 and 2, and for example, as shown in FIG. 6, two sendust films (4) and two soft magnetic alloy films (5) are used. The same effect can be obtained by alternately stacking (1). In the case of this embodiment, although the electromagnetic conversion characteristics are slightly inferior to those of the above-mentioned embodiment, the adhesive force of the film,
The bending strength is further improved, and the yield and environment resistance can be improved. The object of the present invention can be sufficiently achieved even if the interface between the ferrite forming the magnetic core and the sendust film (4) is formed in a trapezoidal shape or a circular shape as shown in FIG. Is.

In each embodiment, the sendust film (4) is provided on the magnetic core halves (1) and (2) made of Mn-Zn ferrite or the like. Sendust film (4) from the adhesive force with the film (5)
And that the pseudo gap noise is 1 at the interface between the ferrite and the soft magnetic alloy film (5).
This is because 0 dB or more is output, but it is suppressed to 1 dB or less at the interface with the sendust film (4).

Next, the soft magnetic alloy film (5) used in the present invention
Will be described in detail. The soft magnetic alloy film (5) is F
e or Fe and T, L, boron B, and carbon C are characterized by containing 90 atomic% or less of Fe, which is an element responsible for magnetism, to obtain soft magnetic characteristics.
Bs of 10 KG or more can be obtained by containing at least atomic%.

If the element T (= Co, Ni) is replaced by Fe and added in an amount of 5 atomic% or less, a magnetostriction constant of 10 ⁻⁶ to 10 ⁻⁷ can be obtained. However, when the total amount of B and C is relatively large, it is not necessary to add T.

The element L (= Zr, Nb, Hf, Ta) is 5
Addition of about 15 atomic% improves the soft magnetic properties and makes it easier to obtain an amorphous phase in the state prepared by the vapor phase quenching method (the state before heat treatment).

Boron B contains Fe as a main component by adding 0.5 to 15 atomic% or more b. c. It is possible to suppress the grain growth of the c phase and further suppress the growth of the compound phase which adversely affects the soft magnetic properties.

By adding 0.5 to 15 atomic% of carbon C, it becomes easy to obtain an amorphous phase which improves the soft magnetic characteristics, and b. c. The precipitation of phase c can be made uniform.

Further, the thermal stability is improved by heat treating the soft magnetic alloy film as described above at a high temperature.

The soft magnetic alloy film used in the magnetic head of the present invention is a process of obtaining an amorphous alloy of the above composition or a crystalline alloy containing an amorphous phase by a vapor phase quenching method such as a sputtering method or an evaporation method. And a heat treatment step of subjecting the alloy obtained in these processes to a heat treatment to precipitate fine crystal grains.

The reason why the alloy is heat-treated here is that the as-deposited alloy (asdepo) contains a considerable amount of amorphous phase, has a low Bs, and has insufficient soft magnetic properties. Is.

As the sputtering apparatus, existing ones such as RF bipolar sputtering, magnetron sputtering, tripolar sputtering, ion beam sputtering, and facing target type sputtering can be used.

The soft magnetic alloy films having the following compositions were formed on a Fe target by using an RF bipolar sputtering device.
A composite target in which pellets of r, Nb, Hf, Ta, B, and C (graphite) were appropriately selected and arranged was sputtered using Ar gas to form a film having a thickness of 5 to 6 μm. As the substrate, a crystallized glass substrate having a size of 4 mm × 24 mm was used.

Various heat treatments were applied to the obtained alloy films to examine the influence of the composition of the alloy films on μ, Hc, λs and Bs. All the heat treatments are performed in a non-magnetic field, the temperature is raised to the set temperature for 40 minutes, and the temperature is lowered from the set temperature to room temperature.
It was carried out at 5 ° C / min. In addition, the film structure at that time is
It was examined using an X-ray diffractometer using Kα rays.

The magnetic permeability μ was measured using a figure 8 coil,
The coercive force Hc was measured by a DC BH loop tracer, the saturation magnetic flux density Bs was measured by VSM, and the magnetostriction constant λs was measured by an optical lever method.

The characteristics of the soft magnetic alloy film (5) measured as described above are shown in Tables 2 to 5 and FIGS. 8 to 11.

[0036]

[Table 2] Table 2 shows that Fe-Ta-BC has a temperature of 550 ° C and 65%.
It shows the relationship between the magnetic permeability μ at 1 MHz after the heat treatment at 0 ° C., the coercive force Hc, the magnetostriction constant λs, the saturation magnetic flux density Bs, and the film composition. It is apparent from Table 2 that the soft magnetic alloy film (5) used in the magnetic head of the present invention is particularly sample No.
In case of 3, μ (1 MHz) 0.1 Oe of 3000 or more
The following shows Hc, 10 ⁻⁷ λs, and Bs of 15 KG or more.

FIG. 8 shows sample No. 3 in Table 2. Fe of 1
_{8 is} an X-ray diffraction pattern of a _80.8 Ta _7.0 B _7.5 C _4.7 film.

As is clear from FIG. 8, in the diffraction pattern immediately after sputtering, b. c. The reflection of the {110} plane and the {220} plane of c-Fe appears. The crystal grain size obtained from the Sherrer equation is about 8 nm, and the fine b. c.
c. It can be seen that the phases are shown. Sample N
o. 1 b. c. c. No crystalline phase other than the phase has precipitated.

FIG. 9 shows the sample No. of Table 2. No. 1 (black circle) and No. 3 is a graph showing the relationship between μ (1 MHz) of 3 (white circle) and heat treatment temperature.

As is clear from FIG. 1 is 5
The magnetic permeability μ is 20 in the temperature range of 00 ° C to 600 ° C.
Sample No. 3 to about 4 from room temperature
Μ is 1000 or more in the range of 50 ° C, about 550 ° C to about 6
It shows a value of 2000 or more in the temperature range of 50 ° C.

FIG. 10 shows sample No. 2 in Table 2. No. 1 (black circle) and No. 3 is a graph showing the relationship between the magnetostriction λs of 3 (white circle) and the heat treatment temperature. 10, sample No. 1
At about 650 ° C., sample No. It can be seen that in No. 3, when heat treatment at about 600 ° C. or higher, λs shows a small value of 10 −7.

FIG. 11 shows sample No. 1 shows the relationship between Bs of 1 and the heat treatment temperature. The value in the amorphous state immediately after sputtering is 7 kG, but after heat treatment at 550 ° C. or higher, b. c. c. 15.6 by precipitating the phases
It can be seen that it shows the value of kG. In the amorphous state, the moment of Fe was reduced by Ta, B, and C, but it was heat treated to contain a large amount of Fe. B. c. It is considered that by precipitating the c phase, the decrease of the moment due to Ta, B, and C was reduced and Bs was increased.

[0043]

[Table 3] Table 3 shows the relationship between the film composition and μ, Hc, and Bs of 1 MHz when Ta in Fe-Ta-BC is completely replaced with Zr, Hf, and Nb as other compositions. As with Table 2, it can be seen that the soft magnetic properties of high saturation magnetic flux density, high magnetic permeability and low magnetostriction constant are exhibited.

[0044]

[Table 4] Table 4 shows a similar relationship when Co and Ni are added to Fe-Ta-BC. It can be seen that the addition of Co or Ni has the effect of positively shifting λs. The soft magnetic characteristics are good, and the decrease of Bs is suppressed to a small level. Further, although λs becomes negative in the high temperature heat treatment, it is possible to shift λs to a positive value by adding Co and Ni in a small amount to almost zero.

In the soft magnetic alloy film (5) of each composition described above, all the heat treatments are performed in the absence of a magnetic field. However, the heat treatments are performed in a static magnetic field and the hard axis of magnetization is used as a magnetic path, or in a rotating magnetic field. It is also possible to further improve the soft magnetic characteristics by suppressing the macroscopic anisotropic dispersion by heat treatment.

[0046]

[Table 5] Table 5 shows comparative examples for the respective compositions of the soft magnetic alloy film (5) of this example. The soft magnetic alloy film (5)
It is a sample of a portion exceeding the composition range of. H in the table
The values of c and λs do not exist because the sample was unsaturated and could not be measured in the applied magnetic field of ± 100 Oe.

As is clear from Table 5, when the composition range of the present invention is exceeded, μ (1 MHz) becomes extremely small, less than 10, which is unsuitable as a core material of a magnetic head.

As the soft magnetic alloy film (5) used in the present invention, in addition to the above-mentioned ones, a soft magnetic alloy film proposed by the present applicant in JP-A-3-131006,
That is, it is represented by Fe _x M _z C _w , and the composition ratio x, z, w is 50 (65) ≦ x ≦ 96 (85), 2 (4) ≦ in atomic%.
z ≦ 30 (20), 0.5 ≦ w ≦ 25, x + z + w = 1
No. 00 soft magnetic alloy film (M is Ti, Zr, Hf, Ta,
One or more of Mo and W) and Fe _x T _y M
_z C, the composition ratio x, y, z, w is 50% in atomic%
x ≦ 96, 0.1 ≦ y ≦ 10, 2 ≦ z ≦ 30, 0.5 ≦
w ≦ 25, x + y + z + w = 100 (T is one or more of Co and Ni, M is Ti, Zr, Hf, T
It is also applicable to the soft magnetic alloy film (5) made of one or more of a, Mo and W).

[0049]

As described above, according to the present invention, the adhesive force of the magnetic cores of the sendust film and the soft magnetic alloy film is improved while the electromagnetic conversion characteristics of the conventional magnetic head are maintained, and the magnetic bar-coupling is cut. In the process, film peeling, partial damage and loss of the film are prevented, the yield is improved, the bending strength of the manufactured magnetic head is improved, and the running reliability is improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a magnetic head according to an embodiment of the invention.

FIG. 2 is a top view of the same.

FIG. 3 is a diagram showing a method of processing a magnetic bar of a magnetic head of the present invention.

FIG. 4 is a diagram showing a method of processing the magnetic bar similarly.

FIG. 5 is a diagram showing a magnetic bar combination of the magnetic head of the present invention.

FIG. 6 is a diagram showing another embodiment of the magnetic head of the present invention.

FIG. 7 is a diagram showing another embodiment of the magnetic head of the present invention.

FIG. 8: X of the soft magnetic alloy film used in the magnetic head of the present invention
The graph which shows a line diffraction pattern.

FIG. 9 is a graph showing the relationship between the magnetic permeability μ of the soft magnetic alloy film and the heat treatment temperature.

FIG. 10 is a graph showing the relationship between the magnetostriction constant λs of the soft magnetic alloy film and the heat treatment temperature.

FIG. 11 is a graph showing the relationship between the saturation magnetic flux density Bs of the soft magnetic alloy film and the heat treatment temperature.

FIG. 12 is a perspective view showing the shape of a conventional magnetic head.

FIG. 13 is a top view of a conventional magnetic head.

FIG. 14 is a diagram showing a combined state of magnetic bars of a conventional magnetic head.

[Explanation of symbols]

 1, 2 Magnetic core half body 3 Gap opposing surface 4 Fe-Al-Si film 5 Soft magnetic alloy film G Magnetic gap

Claims (1)

[Claims] 1. A magnetic head in which a pair of magnetic core halves made of an oxide magnetic material are opposed to each other through a magnetic gap, and Fe-Al-Si-based materials are respectively provided on opposing surfaces of the pair of magnetic core halves. With the soft magnetic film in contact with the oxide magnetic material, the Fe-Al-Si film and the Fe-Al-S film are formed.
A magnetic head comprising at least one i-based soft magnetic film and at least one soft magnetic alloy film different from each other.