JPH0624043B2 - Magnetic head - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates generally to a magnetic head using a Fe—Si—A alloy magnetic film, and particularly for high frequencies and high S / N ratio required. It can be suitably used for density recording heads, mainly video heads, digital heads and the like.

2. Description of the Related Art Recent improvements in recording density in the field of magnetic recording technology have been remarkable, and accompanying this, for example, intertracking with respect to a magnetic head as an electromagnetic conversion element, increase in saturation magnetization of the core material, and high frequency region. There is a growing demand for improved magnetic permeability.

In recent years, a thin film laminated magnetic head using a Fe—Si—A alloy magnetic film has been rapidly attracting attention as a magnetic head that satisfies the above requirements in the field of magnetic recording. An example of the magnetic head is shown in FIGS. The structure will be briefly described.

Referring to FIG. ₂ , SiO ₂ —Li ₂ O—A ₂ O ₃
Fe-Si-A is formed on the substrate 11 made of a crystallized glass.
The alloy thin film 12 is formed with a film thickness of 1 to 20 μm. Then, a nonmagnetic insulating film made of SiO ₂ , that is, an interlayer film 13 is formed on the alloy magnetic film 12 to have a film thickness of 0.03 to 0.5 μm.

Further, the magnetic film 12 and the non-magnetic insulating film 13 are stacked a required number of times to form the magnetic film structure 14. The thickness of the magnetic film 12 and the non-magnetic insulating film 13 and the number of times of lamination are appropriately set so that the thickness of the laminated portion becomes the track width w (FIG. 2).

Then, a glass film 15 is formed on the magnetic film structure 14, and another substrate 16 is laminated thereon. As the glass film 15, SiO ₂ —B ₂ O ₃ —ZnO based bonding glass is used. The substrate 16 is made of the same material as the substrate 11.

The laminated film structure 17 thus manufactured is cut in the laminated thickness direction to form a pair of core half blocks 18 and 19 as shown in FIG. 1, and at least one of the core half blocks is formed. The winding groove 20 is formed in the half body, in this example, the core half body 18.

Then, in order to strengthen the joining of the abutting surfaces of the two core half blocks 18 and 19, conventionally, as shown in FIG. Body 1
After forming chamfered portions 22 on both side surface portions of 9, and also forming recesses 23 on the opposite side of both core halves from the gear tap portion,
The abutting surfaces of both core half blocks 18 and 19 are polished, and then a non-magnetic gap spacer 21 made of SiO _{2 is formed.}
To form.

Thereafter, the core half blocks 18 and 19 are butted against each other at the butted surfaces, and the chamfered portion and the recess are filled with PbO—B ₂ O ₃ based mold glass to join the two half block blocks.

Finally, R polishing processing and other forming processing and winding processing are performed to form a tape sliding surface.
Is obtained.

The magnetic head 10 having such a structure has extremely good magnetic characteristics. However, as shown in FIG. 3, a crack 24 is generated in the mold glass portion 22 near the gear portion 21 with the passage of time during use. As a result, the joining force between the two core halves is weakened, the gear parts are separated from each other, and the predetermined magnetic characteristics cannot be obtained, which causes a problem.
In addition, such cracks in the mold glass portion also occur during the manufacture of the magnetic head, and if the yield is less than 10%, the manufacturing efficiency is extremely poor.

The present inventors have conducted many research experiments to solve such problems, and as a result, the substrates 11, 16 using the materials as described above, the glass film 15, and the magnetic film structure 1 have been used.
4. The thermal expansion coefficients of the mold glass 22 are greatly different, and due to the difference in the thermal expansion coefficient, excessive tensile stress or compressive stress is generated in the mold glass part, and cracks are generated in the mold glass part. I found that

Further, it is important that the magnetic heads have substantially the same thermal expansion coefficient, and at the same time, since the heads are generally manufactured by a vacuum deposition method, a sputtering method, an ion plating method, etc., due to process restrictions, Between the heat-resistant temperature of the substrate and the softening points of the glass film and the mold glass, the relationship of (heat-resistant temperature of the substrate)> (softening point of the glass film)> (softening point of the mold glass) is required. It was found that it is necessary to select each material so as not to cause an excessive chemical erosion reaction between each material of the glass film and the mold glass.

As a result of studying many materials from such a viewpoint, the present inventors have shown that the substrate is represented by (MnO) × (NiO) _1-x (where 0 <x <1), and mainly has a rock salt structure. The non-magnetic substrate material used as the glass film is SiO ₂ −.
By using Na ₂ O—A ₂ O ₃ based glass, SiO ₂ —B ₂ O ₃ —Na ₂ O based glass as the mold glass, and SiO ₂ as the interlayer film and the gap layer, the mold glass portion is formed. It has been found that it is possible to manufacture a magnetic head using a high quality Fe-Si-A alloy magnetic film that does not cause cracking.

The present invention has been made based on such novel findings.

OBJECT OF THE INVENTION It is an object of the present invention to provide a magnetic head using a high quality Fe-Si-A alloy magnetic film in which no crack is generated in the mold glass part.

Another object of the present invention is to improve the yield from less than 10% of the conventional yield to 8%.
Fe-Si- which can be improved to about 0%
It is to provide a magnetic head using an A alloy magnetic film.

Means for Solving the Problems The above-mentioned objects are achieved by a magnetic head using the Fe—Si—A alloy magnetic film according to the present invention. In summary, the present invention provides one substrate and Fe (83-94 wt.
%)-Si (4 to 11 wt%)-A (2 to 6 wt%)
A magnetic film structure formed by alternately laminating an Fe-Si-A alloy magnetic film having the composition of 10 and an interlayer film, a glass layer laminated on the thin film structure, and a glass layer laminated on the glass film. In a magnetic head constructed by abutting two core halves made of a laminated film structure having the other substrate formed thereon and reinforcing and joining the two core halves with mold glass, the substrate is (M
nO) × (NiO) _1-x (where 0 <x <1), and the glass film is made of SiO ₂ —Na ₂ O—A. _{It is made of 2} O ₃ based glass, and the mold glass is SiO ₂ -B.
_The magnetic head is made of ₂ O ₃ —Na ₂ O based glass.

Next, the magnetic head of the present invention will be described in more detail.

A. Selection of Substrate Material: The present inventors first examined the substrate material when selecting the materials for the substrate, the glass film and the mold glass.

Conventionally, as a substrate material, as described above, SiO ₂ -L is used.
Although i ₂ O-A ₂ O ₃ -based crystallized glass has been used, according to the study by the present inventors, such crystallized glass has a low heat resistance temperature of about 650 to 800 ° C. It was found that the selection range of the material of the laminated glass film 12 was extremely limited. In addition, a chemical erosion reaction occurs due to a large difference in basicity between the matrix phase (main component is SiO ₂ ) and the mold glass in which the conventional PbO-B ₂ O ₃ based glass is used. However, there is a problem that it is difficult to accurately set the remaining amount of the substrate or the depth of the gap.

Therefore, the inventors of the present invention selected (1) the thermal expansion coefficient (12) of the Fe--Si--A alloy magnetic film when selecting the material of the substrate.
Having a coefficient of thermal expansion close to 0 to 150 × 10 ⁻⁷ / ° C., (2) heat resistant temperature of 800 ° C. or higher, (3) not extremely reacting with low melting point glass such as mold glass, We have found that it is essential as a selection condition.

As a result of the research and experiment by the present inventors, (MnO) × (NiO)
_The non-magnetic substrate material represented by _1-x (where 0 <x <1) and mainly having a rock-salt structure, especially the substrate material with x = 0.55 must satisfy the above selection conditions. Found. Table 1 shows various properties of the material in comparison with conventional materials.

B. The Selection conventional glass film material of the glass film _material, SiO ₂ -B ₂ O 3 -Zn
Although an O-based bonding glass was used, according to the results of the research and experiments conducted by the present inventors, ZnO-containing glass was found to have ZnO in the film by a method such as spattering that is usually adopted when manufacturing a magnetic head. It has been found that there is a problem that it is difficult to enter, and such compositional deviations cause problems that various properties important in constructing the magnetic head, such as the thermal expansion coefficient and the softening point, change. Table 2 shows the bulk composition and the film composition.

Therefore, the inventors of the present invention, when selecting the material for the glass film, have (1) a coefficient of thermal expansion close to that of the substrate (134 × 10 ⁻⁷ / ° C.), and (2) heat resistance temperature (softening). It is essential as a selection condition that (point) is higher than the working temperature of the mold glass by 50 ° C. or more, (3) does not contain ZnO to reduce the compositional deviation, and (4) does not react extremely with the substrate. I understand.

As a result of research and experiments conducted by the present inventors, SiO ₂ —Na ₂ O—A
It has been found that ₂ O ₃ based glass is optimal. An example of the composition of the material is shown in Table 3 and Table 4 shows various characteristics of the material. Further, Table 5 shows the bulk composition and the film composition when the film was prepared by using the glass film material according to the present invention with Ar pressure of 4 × 10 ^-3 sputtering. It will be understood that it has not occurred.

C. Selection of Mold Glass Material Conventionally, as a mold glass material, as described above, P
bO-B ₂ O ₃ based glass is used, between the mold glass and the substrate, for the difference in basicity is large, cause chemical erosion reaction, the substrate is eroded, leaving the amount or Giyatsupu depth of the substrate Had a problem that it was difficult to set up correctly.

Therefore, the inventors of the present invention, when selecting the material for the mold glass, have (1) a coefficient of thermal expansion close to that of the substrate (134 × 10 ⁻⁷ / ° C.), and (2) a working temperature of glass. It has been found that the softening point of the film is 630 ° C. or lower, preferably 50 ° C. or more lower than the softening point of the glass film, and (3) does not react extremely with the substrate, which are essential as selection conditions.

As a result of research and experiment by the present inventors, it was found that SiO ₂ —B ₂ O ₃ —Na ₂ O based glass is the most suitable as the mold glass. Examples of the composition of the material are shown in Table 6 and Table 7.
The various characteristics of the material are shown in comparison with the conventional mold glass material.

Next, examples of the thin film magnetic head according to the present invention will be described.

Example 1 A magnetic head according to the present invention having a structure as shown in FIG. 1 was produced using a DC magnetron sputtering device (RF bias application). FIG. 4 schematically shows the sputter device.

The DC sputtering device 30 includes a cathode 32 connected to a high voltage DC power supply 31 and a substrate holder 34 connected to an RF bias power supply 33 and electrically insulated.
The target 35 was placed in the holder, and the substrate 11 was placed in the holder 34. The apparatus was evacuated from one port 36 with a vacuum pump (not shown), and Ar gas was introduced from the other port 37.

As the target 35, Si 10.5 wt%, A5.
Hot-pressed diameter 4 consisting of 5 wt% balance Fe
An inch with a thickness of 4 mm was used.

The substrate 11 has a coefficient of thermal expansion of 134 × 10 ⁻⁷ / ° C. (Mn
O) × (NiO) _1−x (where x = 0.55), and the non-magnetic substrate material with a diameter of 2 inches, which is mainly composed of rock salt type structure, is polished to a surface roughness of 150Å. Used.

Ar pressure was 4 × 10 ⁻³ Torr, and input power was 500W. The Fe—Si—A alloy film 12 was formed on the substrate 11 to have a film thickness of 4.7 μm. The formed soft magnetic film was then heat-treated.

Then, an interlayer film 13 was formed on the Fe-Si-A alloy film 12. The interlayer film was produced by using the magnetron sputtering apparatus used for producing the Fe-Si-A alloy film as an R film.
Use the one connected to the F power supply, and the target diameter is 4
Inch, 5 mm thick SiO ₂ was used. Ar pressure was 4 × 10 ⁻³ Torr, and input power was 300W. Under these conditions, the SiO ₂ film is 0.3 μm thick on the magnetic film of the substrate.
Formed in.

Next, the magnetic film 12 and the insulating film 13 were sequentially repeated four times on the interlayer film 13 by the above method to obtain a magnetic film structure 14. The total film thickness of the magnetic film structure 14 was 20 μm.

Further, a glass film 15 was formed on the magnetic film structure 14 by ordinary sputtering or the like. The glass film 15 is made of Si
O ₂ (50 wt%)-Na ₂ O (20 wt%)-A ₂
O ₃ (10 wt%), balance BaO, K ₂ O, Ca
A glass having a composition containing O and the like is used, and the Ar pressure is 4 × 10.
A glass film having a thickness of 1 μm was formed by sputtering under the conditions of ⁻³ Torr, RF input of 100 W, and substrate temperature of 100 ° C. Next, another substrate 16 made of the same material as the substrate 11 was laminated on the glass film to produce a laminated film structure 17. The laminated film structure 17 has a temperature of 1 at 650 ° C.
Melt pressing was performed for 5 minutes.

Next, the laminated film structure 17 manufactured in this way is
As shown in FIG. 1, the laminated cores are cut in the thickness direction to form a pair of core half blocks 18 and 19, and a winding groove 20 is formed in the core half body 18. In order to strengthen the joining of the abutting surfaces of the blocks 18 and 19, chamfered portions are formed on both side surfaces of the core half body 19 facing the winding groove 20 as shown in FIG. Also, a recess is formed on the opposite side of both core halves from the gear part, and the abutting surfaces of the core half blocks 18 and 19 are non-magnetic gear spacers made of SiO ₂ after polishing. Two
1 was formed by spattering. Then, SiO ₂ (38 wt%)-B ₂ O ₃ (20 w
t%)-Na ₂ O (22 wt%), the balance K ₂ O,
Mold glass having a composition such as Li ₂ O was melt-filled.

Finally, R polishing and other forming processes and winding process were performed to form a tape sliding surface, and a thin film laminated magnetic head 10 was obtained.

Fifty magnetic heads were manufactured by the above method, but only eight defective products were generated due to the generation of cracks in the mold glass portion, and the yield was 84%.

The magnetic head 10 having such a structure has extremely good magnetic properties, and a relative initial magnetic permeability of 2000 at a coercive force of 0.18 Oe and 1 MHz was obtained. Further, this magnetic head is a VTR magnetic head whose track width is in the film thickness direction, the track width is 20 μm, and the tape head relative speed is 5.8.
When the reproduction output was measured using a metal tape at m / sec, the same performance as that of a conventional magnetic head using a substrate, a glass film, and mold glass was obtained at a reproduction output of 5 MHz.

In the thin film magnetic head according to the present invention, cracks did not occur in the mold glass portion near the gear portion even during the manufacturing process and during long-term use.

The thin-film laminated magnetic head according to the present invention configured as described above is a thin-film laminated magnetic head using a high-quality Fe-Si-A alloy magnetic film that does not cause cracks in the mold glass portion. Further, it is possible to provide the advantage that the yield can be improved from less than 10% of the conventional case to about 80%.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a thin film laminated magnetic head according to the present invention. FIG. 2 is a partial plan view showing the layer structure of the magnetic head of FIG. FIG. 3 is a plan view showing the gear part of the magnetic head shown in FIG. FIG. 4 is a schematic configuration diagram of a sputtering device for producing a thin film laminated magnetic head. 10: Thin film laminated magnetic head 11, 16: Substrate 12: Magnetic film 13: Interlayer film 15: Glass film

Claims (4)

[Claims] 1. A substrate, and Fe--Si-- on the substrate.
It has a magnetic film structure in which an A alloy magnetic film and an interlayer film are alternately laminated, a glass film laminated on the thin film structure, and the other substrate laminated on the glass film. In a magnetic head formed by abutting two core halves made of the laminated film structure, and reinforcing the two core halves with a mold glass, the substrate is (MnO) × (NiO) _1-x
(However, 0 <x <1), and the glass film is made of Si with a non-magnetic substrate material that mainly has a rock salt structure.
O ₂ -Na _{2 O-A} prepared in 2 _{O 3} based glass, and molded glass magnetic head, characterized in that it is produced by the _{SiO 2 -B 2 O 3 -Na 2} O -based glass. 2. The substrate is (MnO) × where x = 0.55.
The magnetic head according to claim 1, which is represented by (NiO) _1-x (where 0 <x <1) and is made of a non-magnetic substrate material having a rock-salt type structure as a main component. 3. The glass film is made of SiO ₂ (40-60 wt.
_{%) - Na 2 O (10~30wt} %) - A 2 O 3 (5
The magnetic head according to claim 1 or 2, wherein the magnetic head is made of glass whose main component is -15 wt%. 4. The mold glass is made of SiO ₂ (25 to 45).
_{wt%) - B 2 O 3} (10~30wt%) - Na 2 O
The magnetic head according to claim 1, 2, or 3, which is made of glass containing (10 to 30 wt%) as a main component.