JPH1011710A - Production of magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing magnetic head which allows the use of a glass having a relatively high m.p. at the threshold temp., at which a core material maintains crystal magnetic anisotropy, or below and makes it possible to obtain a magnetic head good in the strength and environmental resistance as the final product. SOLUTION: Approximately V-shaped plural grooves 11 are formed by dicing at a prescribed pitch size (a) on the front surface of a substrate 10; (A). 'SENDUST(R)' which is an FeAlSi alloy, amorphous material, such as CoZrNb, or a fine crystalline material 12, such as FeTaN, is formed a the prescribed film thickness corresponding to a track width by a vacuum vapor deposition method or sputtering method on the wall surfaces of the respective grooves; (B). Sheet glass 13 having a high m.p. is arranged to come into contact with the substrate and sheet glass 14 having a low m.p. is laminated thereon and is melted by heating to 650 deg.C for one four in a nitrogen atmosphere, by which the low melting glass is packed into the respective grooves; (C). The low melting glass 13 (14) swollen out to the apex positions between the approximately V-shaped grooves 11 adjacent to each other is ground until the surfaces are made flush with each other; (D).

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 a magnetic recording / reproducing apparatus such as a video tape recorder.
More specifically, the present invention relates to a method of manufacturing a magnetic head having a soft magnetic thin film forming a magnetic circuit and a substrate supporting the soft magnetic thin film.

[0002]

2. Description of the Related Art With the advancement of magnetic recording technology, high coercivity media such as metal tapes have become mainstream.
A core material used for a magnetic head is required to have a high saturation magnetic flux density and be formed in a narrow track. Under such circumstances, a magnetic head chip 21 as shown in FIG. 5, for example, is used in a conventional magnetic head. The magnetic head chip 21 uses a soft magnetic thin film 22 having a high saturation magnetic flux density as a core material.
FIG. 6 shows the configuration of the main part of the magnetic head chip according to the manufacturing processes (A) to (D). As shown in FIG. 6A, as a manufacturing procedure, first, a plurality of substantially V-shaped grooves are continuously formed at a predetermined pitch size on the substrate 23, and then the soft magnetic thin film 22 is formed on the groove wall surface. Are formed with a film thickness corresponding to the track width. And the low melting glass 24
When the substrate 23 and the soft magnetic thin film 22 are molded by
As shown in (B), at least two glass sheets having different melting points are prepared on the groove of the substrate, and the glass sheets 25 having a lower melting point are stacked and arranged so as to be located below, and sequentially melted by heating. 6 (C), the soft magnetic thin film 22 is sandwiched between the substrate 23 and the low-melting glass 24 in the magnetic head chip 21 as shown in FIG. Structure.

[0006] Subsequently, as shown in FIG. 6 (D), the portion of the filled low melting point glass 24 protruding from the groove is ground to flatten the surface. Thereafter, as shown in FIG. 7, a winding groove is provided on the substrate 23 in the same manner as a known ferrite head for a video tape recorder, and the gap surface 25 is formed.
Is formed. Then, as shown in FIG. 8, the two substrates 23 are opposed to each other, and pressure-fixed in a state where the positions of the soft magnetic thin films 22 correspond to each other. The substrate 23 is joined by heating to form the core block 26. Next, the core block 26 is cut at a substantially central position of the opposing groove (a cut portion is indicated by a broken line) to obtain a magnetic head chip as shown in FIG.

[0004]

Generally, low-melting glass must contain a large amount of lead oxide as a technique for lowering the melting point of the glass to a temperature not higher than the limit temperature. Sodium oxide and potassium oxide are also contained in large amounts, and as a result, the amount of lead oxide contained in each grinding and polishing process in the production of magnetic heads reduces the strength of the glass, resulting in chipping and cracking. And the like, and a problem that the yield is reduced occurs. In addition, since the magnetic head contains a large amount of an alkaline component, when the magnetic head is formed, it tends to react with moisture in the air, resulting in poor environmental resistance. Furthermore, as described above, when a laminated glass is used as the low-melting glass filled in the substantially V-shaped groove of the magnetic head, the glass having a low melting point is arranged at a position in contact with the substrate, so that after the glass is filled. When the protruding portion is ground to form a substrate block, all of the glass near the substantially V-shaped groove becomes the glass having the lowest melting point, and the above-mentioned effects on the characteristics of the low melting glass cannot be avoided, and the manufacturing is difficult. And lower the yield in
A problem arises in that the environmental resistance deteriorates.

[0005] At present, high coercive force media is becoming mainstream, and as core materials, FeAlSi alloys such as sendust and amorphous alloys such as CoZrNb or FeTa are used.
A microcrystalline material such as N is used. In Sendust, the limit temperature for maintaining the crystalline magnetic anisotropy is about 700 ° C., the limit temperature for maintaining the amorphous state of the amorphous alloy is about 500 ° C., In a microcrystalline material, a material exhibiting good soft magnetic properties due to the refinement of crystal grains has a limit temperature of about 550 ° C., and thus the low melting point glass used has a relatively low working temperature of 500 ° C. to 650 ° C. The glass used similarly suffers from the aforementioned problems.

The present invention has been made in view of the above-mentioned problems in the prior art, and allows the use of glass having a relatively high melting point below the limit temperature at which the core material maintains the crystalline magnetic anisotropy. An object of the present invention is to provide a manufacturing method capable of obtaining good strength and environmental resistance.

[0007]

According to a first aspect of the present invention, a plurality of substantially V-shaped grooves are continuously formed on a surface of a substrate, and a soft magnetic thin film is formed on a wall surface of the grooves. After filling the groove with the low-melting glass, a joining surface for facing the surfaces formed by the soft magnetic thin films to each other via a gap is cut out by shaving the filled low-melting glass, and the substrate block is cut out. In the method of manufacturing a magnetic head, when filling the substantially V-shaped groove on the substrate with low-melting glass, two or more types of glasses having different melting points are laminated and used. By placing the lower glass so that the higher glass is in contact with the substrate, and placing the lower melting glass at the upper position, heating it, and lowering the melting temperature of the glass relatively, it is possible to melt within the limited temperature range. Is to do

According to a second aspect of the present invention, in the first aspect of the present invention, as a method of laminating two or more types of glasses having different melting points, a low melting point glass is placed on top of the higher melting point glass in contact with the substrate. It is formed using a sputtering method.

According to a third aspect of the present invention, in the first aspect of the present invention, as a method of laminating two or more types of glasses having different melting points, a glass having a low melting point is provided on a glass having a higher melting point in contact with a substrate. It is designed to be formed as fine powder.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a configuration of a main part of a magnetic head chip according to an embodiment of the present invention in accordance with manufacturing processes (A) to (D). FIG.
As shown in FIG. 1A, a substrate 10 constituting a head chip is made of a non-magnetic substrate material such as photosensitive crystallized glass, crystallized glass, or ceramics, or an oxide magnetic material such as soft magnetic ferrite. Are prepared. As a manufacturing procedure, first, on the surface of the substantially rectangular parallelepiped substrate 10,
A plurality of substantially V-shaped grooves 11 having a predetermined pitch dimension a are formed adjacent to each other by dicing. Thereafter, as shown in FIG. 1B, a predetermined film thickness corresponding to the track width is formed on each groove wall surface by a vacuum evaporation method or a sputtering method.
An amorphous material such as Sendust or CoZrNb, which is a FeAlSi alloy, or a microcrystalline material 12 such as FeTaN
Is formed.

Next, as shown in FIG. 1 (C), when filling each adjacent substantially V-shaped groove with glass, two or more types of glasses having different melting points are used, and A plate glass 13 is disposed so as to be in contact with the substrate, and a plate glass 14 having a low melting point is laminated thereon, and the
Heat to 650 ° C. for a time to melt, and fill each groove with low melting glass.

The filling process will be described in more detail. When heating the laminated glass, the upper glass sheet 14 not in contact with the substrate first melts, and at this time, the glass sheet 13 in contact with the substrate gradually softens. At this stage, even at a low temperature, which is not the original working temperature, the upper glass sheet 14 is in a molten state, so that the surface tension of the glass sheet 13 in contact with the substrate at the interface between the glass sheets 13 and 14 changes, and the melting is stopped. What happens is that it is possible to fill all of the plurality of successive substantially V-shaped grooves with glass.

As a result, it is possible to use glass having various characteristics required for a magnetic head even when the temperature is higher than the limit temperature of various alloy films. If the thickness is equal to or more than the volume of the plurality of substantially V-shaped grooves, the lower low-temperature glass at the top is removed by subsequent grinding when the glass is melted. As the glass when it becomes full, it becomes possible to use glass having a high working temperature.

Table 1 below shows a composition table of the sheet glass 13 having a high working temperature used in the present invention, and FIG. 5 shows EPMA (Electron P) before melting the sheet glass 13.
5 shows the results of analysis by the robe Micro Analizer

[0015]

[Table 1]

FIG. 6 shows an EPMA analysis result of the glass sheets when the laminated glass sheets 13 and 14 are melted to form a magnetic head chip, and the glass sheets are identified as having a high working temperature before melting. According to this result, it can be confirmed that a glass having desired various properties can be obtained by setting an appropriate plate thickness.

At this time, the thickness x of the plate glass 13 is not less than a volume that can fill the substantially V-shaped grooves 11 formed continuously on the substrate, and the adjacent substantially V-shaped grooves 11 are filled after the glass is filled. In order to minimize the amount of grinding when grinding the glass to the apex position between the two, the thickness must be set to the minimum necessary. The thickness of the laminated glass sheet 14 is only required to change the surface tension of the glass sheet 13, and is therefore set to the minimum thickness. In this embodiment, since the example of use in Sendust is shown, the plate glass used is lead-based and has the physical properties shown in Table 2 below. The working temperature of the plate glass 14 is the limit temperature of Sendust. 620 below
° C.

[0018]

[Table 2]

Next, as shown in FIG. 1 (D), the protruding low-melting glass 13 (14) is ground to the apex position between adjacent substantially V-shaped grooves 11 so that the surfaces thereof match. Then, as shown in FIG. 2, an internal winding groove 15 and an external winding groove 16 are formed on both surfaces of the substrate 10, and
A gap spacer material (not shown) made of a non-magnetic material such as SiO ₂ is formed on the gap facing surface 17 which is the surface on which the V-shaped groove is formed, by a vacuum evaporation method or a sputtering method so as to have a predetermined gap length. The substrate block 18 is formed. Thereafter, the gap opposing surfaces 17 of the pair of substrate blocks 18 as shown in FIG. 3 are opposed to each other, and each soft magnetic thin film 12 is linearly aligned and pressed, and is adhered and fixed with the low melting point glass 13. The core block 19 is formed. Subsequently, the core block 19 is cut at a predetermined pitch dimension b to obtain the magnetic head chip 1 shown in FIG. Thereafter, the magnetic head chip 1 is bonded to a base plate (not shown), and then the coil winding and the tape sliding surface are polished to form a magnetic head. In the above embodiment, two glass sheets having different melting points are used. However, the glass sheet may be other than lead-based glass, and three or more glass sheets may be used at the same time. Further, as a method of laminating, a method of forming the second and subsequent glasses on the first glass by a sputtering method, and a method of forming the same state in a powder state can obtain the same effect.

[0020]

The method of manufacturing a magnetic head according to the present invention is required for preparing a laminated low-melting glass in order to fill a substantially V-shaped groove with the low-melting glass. A glass with a relatively high working temperature with various characteristics is used as the first glass in contact with the substrate, and the second and subsequent glasses can be melted at a relatively low working temperature within the limited temperature range of various alloy films. By sequentially heating these glasses, the upper glass not in contact with the substrate first melts, and at this time, the first glass in contact with the substrate is melted.
In the stage where the glass gradually softens, even at a low temperature other than the original working temperature, the upper glass is in a molten state, so that the first glass and the second glass, which are opposite to the substrate side, are When the surface tension of the first glass changes at the interface and melting occurs, it becomes possible to fill all the plurality of continuous substantially V-shaped grooves with glass. As a result, it is possible to use a glass having various properties required for a magnetic head even when the temperature is equal to or higher than the temperature limit of various alloy films. Therefore, if the thickness is equal to or greater than the volume of the plurality of substantially V-shaped grooves, when the glass is melted, the upper low working temperature glass is removed by subsequent grinding, so that when the magnetic head is formed. Are all glasses having a high working temperature.

The fact that such a glass having a relatively high melting point can be used means that a glass having a low content of lead oxide and an alkali component can be used. It is possible to use glass having good properties, and the yield is improved.

[Brief description of the drawings]

FIG. 1 shows a configuration of a main part of a magnetic head chip according to an embodiment of the present invention in accordance with manufacturing processes (A) to (D).

FIG. 2 shows a head portion provided with a winding groove in a process of manufacturing a magnetic head chip according to an embodiment of the present invention.

FIG. 3 shows a core block formed by bonding substrates in a process of manufacturing a magnetic head chip according to an embodiment of the present invention.

FIG. 4 is a perspective view showing a magnetic head chip using a soft magnetic thin film according to an embodiment of the present invention.

FIG. 5 is a graph showing the results of EPMA analysis before melting a glass sheet used in an embodiment of the present invention.

FIG. 6 is a graph showing EPMA analysis results of glass after melting used in the embodiment of the present invention.

FIG. 7 is a perspective view showing a magnetic head chip using a conventional soft magnetic thin film.

FIG. 8 shows a configuration of a main part of a conventional magnetic head chip according to manufacturing processes (A) to (D).

FIG. 9 shows a head portion provided with a winding groove in a conventional magnetic head chip manufacturing process.

FIG. 10 shows a core block formed by joining substrates in a process of manufacturing a conventional magnetic head chip.

[Explanation of symbols]

1,21 ... magnetic head chip, 10,23 ... substrate, 11
... substantially V-shaped groove, 12 ... microcrystalline material, 13,14 ... sheet glass, 15 ... internal winding groove, 16 ... outer winding groove, 17 ... gap facing surface, 18 ... substrate block, 19,26 ... core Block, 22: soft magnetic thin film, 24: low melting point glass, 2
5 ... Gap surface.

Claims (3)

[Claims] 1. A plurality of substantially V-shaped grooves are continuously formed on a surface of a substrate, a soft magnetic thin film is formed on a wall surface of the grooves, and
After filling each groove with low-melting glass, a joining surface for facing the surfaces formed by the soft magnetic thin films to each other via a gap is cut out by shaving the filled low-melting glass, and the substrate is cut out. In the method of manufacturing a magnetic head in which blocks are formed, when filling the substantially V-shaped groove on the substrate with low-melting glass, two or more types of glasses having different melting points are laminated and used. The glass with the higher melting point is placed in the lower part so as to be in contact with the substrate, and the glass with the lower melting point is placed in the upper part and heated, and the melting temperature of the glass can be made relatively low, so that it can be melted within the temperature limit A method for manufacturing a magnetic head, comprising: 2. A method for laminating two or more kinds of glasses having different melting points, wherein a low melting point glass is formed by sputtering on an upper part of a glass having a higher melting point in contact with a substrate. The method for manufacturing a magnetic head according to claim 1, wherein: 3. A method of laminating two or more kinds of glasses having different melting points, wherein a glass having a low melting point is formed as a fine powder on an upper part of a glass having a higher melting point in contact with a substrate. The method for manufacturing a magnetic head according to claim 1.