JPH0369007A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To provide a longer life by forming soft magnetic thin films on the side wall surfaces on one side of the respective approximately V-shaped grooves on a substrate surface, butting a pair of such substrates on each other and welding the substrates by low melting glass, then subjecting the substrate to an ion exchange treatment. CONSTITUTION:The approximately V-shaped grooves 7 are formed on the substrate B 1 consisting of photosensitive crystallized glass and the soft magnetic thin films 3 are formed on the side walls 7a on one side. Nonmagnetic oxide films 4 are formed as protective films on the films 3. A metallic Ti film 5 and a metallic Cr film 6 are formed continuously in this order to cover the entire part of the grooves 7. The entire part of the grooves 7 of the supporting plate B 1 is then molded by the low melting glass 2 contg. Na and is thereby flattened. Such substrate is cut and a pair of the substrates are butted on each other and are welded by the glass to obtain the head chip. The head chip is immersed into a neutral nitric acid K soln. and is subjected to the ion exchange treatment. The glass is changed to the glass contg. K in this way, by which the higher strength and the longer life are obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a magnetic head used in a video tape recorder or the like.

[Conventional technology]

2. Description of the Related Art Conventionally, a method of manufacturing a magnetic head is known which includes a step of welding a pair of substrates each having a soft magnetic thin film on a gap forming surface using low melting point glass.

In this method, for example, as shown in FIG. 5(a), substantially square grooves 17 are continuously formed by, for example, dicing on the surface of a substrate Bll made of photosensitive crystallized glass, and , one side wall 17a... is formed using a thin film forming technique such as a vacuum evaporation method or a sputtering method.
The predetermined film thickness is l!, which corresponds to approximately half the track width of the magnetic head. Fe-3t-A/! A soft magnetic thin film 13 made of a based alloy is formed.

As shown in FIG. 2B, a non-magnetic oxide film 14 made of Sin is formed as a bottom film on the soft magnetic thin film 13 as a protective film, and then a metal Ti film is formed so as to cover the entire groove 17. These are successively formed in the order of film 15→metal Cr film 16.

Next, a plate-shaped low melting point glass containing sodium is placed on the substrate Bll, and as shown in FIG.
...The entire structure is molded with low melting point glass 12, and the low melting point glass 12 is ground to flatten it.

Then, as shown in FIG. 6(a), the substrate B11 is cut out at a pitch E, and an external winding groove and an internal winding groove are formed on the cut out substrate B11, and a gap surface is processed.

Then, a pair of substrates B11 with winding grooves formed in this way are prepared, and they are pressed and fixed against each other so that their gap surfaces face each other, and the temperature is raised to a temperature at which the low melting point glass 12 has adhesive strength. The glass was welded and joined as shown in the same figure (
As shown in b), a core block 18 is obtained.

This core block 18 is cut at a constant width, and the seventh
As shown in the figure, after a head chip body 20 is obtained, the head chip body 20 is subjected to processes such as tape sliding surface polishing, coil winding, and fixing to a base plate to obtain a magnetic head.

[Problem to be solved by the invention]

However, the low melting point glass 12 containing sodium used for glass welding has drawbacks such as poor abrasion resistance and low hardness, and in manufactured magnetic heads, the glass may chip or break when the tape slides. It has the disadvantage that cracks occur and a long life cannot be achieved.

In this case, a magnetic head that uses low melting point glass containing potassium instead of low melting point glass 12 containing sodium is superior in terms of longevity; however, this low melting point glass containing potassium is Since it is difficult to vitrify compared to the low melting point glass 12 containing the above, it has inferior weldability and workability, and has significant drawbacks in manufacturing magnetic heads.

[Means to solve the problem]

In order to solve the above-mentioned problems, the method for manufacturing a magnetic head according to the present invention is to provide a soft magnetic thin film with a predetermined thickness on one side wall surface of a substantially V-shaped multi-groove formed on a substrate surface. and a step of butting together a pair of substrates on which soft magnetic thin films are formed and welding them with low melting point glass, in which the low melting point glass after welding is subjected to ion exchange treatment It is characterized by having a step of applying.

[For production]

According to the above tank bottom, as for the low melting point glass before welding, it is possible to use glass that is easy to vitrify and has excellent weldability and processability, such as glass containing sodium, to facilitate the manufacture of magnetic heads. , after glass welding,
By ion exchange treatment, the welded glass is changed into glass containing potassium, for example, and the advantages of the glass containing potassium, such as high hardness, high abrasion resistance, high water resistance, and high chemical resistance, are imparted to the magnetic head. , it is possible to extend the life of the magnetic head. Further, since potassium ions have a larger volume than sodium ions, when these are exchanged, the tensile stress within the glass increases, the strength of the glass increases, and the life span is further extended.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

In the magnetic head manufactured by the method for manufacturing a magnetic head according to the present invention, the main body portion is composed of a pair of photosensitive crystallized glass sheets whose gap facing surfaces are formed in a chevron shape, as shown in FIG. 3(b). 1 and Fe5i-Aj formed on one side wall of each chevron-shaped portion 1c! (Sendust) A soft magnetic thin film 3 made of alloy, etc. and a non-magnetic oxide film 4 made of SiO2 etc.
and a metal Ti film 5 formed on both side walls of each chevron-shaped portion 1c.
It has a metal Cr film 6 and a low melting point glass 2' containing potassium (K). Further, each photosensitive crystallized glass 1 has an external winding groove 1a and an internal winding groove 1b, and windings (not shown) are provided in these grooves 1a and 1b.

To manufacture the above magnetic head, as shown in FIG. 1(a), on the surface of a substrate Bl made of photosensitive crystallized glass,
Approximately square-shaped grooves 7 are continuously formed, for example, by dicing, at a pitch A that takes into account the final thickness of the magnetic head and the cutting margin when dividing. At least one side wall of each groove 7 (also one side wall of the chevron-shaped portion 1C)
7a and the normal H to the unprocessed surface of the substrate B1, the angle e
It is desirable that l is approximately equal to the azimuth angle of the final magnetic head configuration. Note that this angle does not require particular precision here. This is because the accuracy of this angle ol is determined by the pitch AI of the grooves 7 and the machining pitch accuracy when dividing.

Next, as shown in FIG. 7(b), one side wall 7a...
The Fe-3i-
A soft magnetic thin film 3 made of an Af-based alloy is formed. Fe-3
For example, the structure of the t-Af alloy is 5.5 wt%
Al-bat.

Something like Fe is common. When a vacuum evaporation method is used to form the soft magnetic thin film 3, as shown in FIG. If Φ is set appropriately, the soft magnetic thin film 3 can be interrupted near the bottom of each side wall 7a due to the shading effect caused by the tops of the adjacent groove walls 7a. The angle Φ is Fe-3t -All! for the soft magnetic thin film 3. When a series alloy is used, considering its characteristics, it is desirable to set the angle in the range of 0 to 45 degrees.

Next, as shown in the same figure (d), on the soft magnetic thin film 3,
A nonmagnetic oxide film 4 made of Stow is formed as a protective film. In this embodiment, the nonmagnetic oxide film 4 is formed only on the soft magnetic thin film 3, but it may be formed so as to cover the entire groove 7. In addition, the nonmagnetic oxide film 4 is made of Sin.

Although a film is shown, the present invention is not limited to this.

Next, as shown in FIG. 4E, a metal Ti film and a metal Cr film 6 are successively formed so as to cover the entire groove 7 . When the metal Ti film 5 and the metal Cr film are formed, the non-magnetic oxide film 4 is interposed as a protective layer between the soft magnetic thin film 3 and is formed directly on the soft magnetic thin film 3. Compared to the case, soft magnetic thin film 3 and metal T
Diffusion with the i-film is suppressed, and characteristic deterioration caused by this diffusion can be reduced.

Next, a plate-shaped low melting point glass containing sodium is placed on the substrate Bl, and as shown in FIG.
The entire structure is molded with low melting point glass 2 to flatten it. When this glass molding is carried out, since the metal Cr film described above covers the entire groove 7..., the wettability of the low melting point glass 2 during melting is good, and shrinkage due to the surface tension of the molten glass increases. It is possible to eliminate the disadvantage that the entire surface is not covered because the particles grow and stick in the form of beads. In addition, if only the metal Cr film is formed directly on the non-magnetic thin film 4 or the substrate B1, it tends to react and foam, but with the metal Ti film 5 interposed, such The problem of foaming is also eliminated. In addition, experiments have shown that when molding with low melting point glass 2, the wetting angle is 60 to 70 degrees with and without metal Cr116, and the wetting angle is 100 to 11 degrees without metal Cr116.
0° and the difference is 30 to 50' is 6I
It has been L'Qed.

Next, as shown in FIG. 2(a), the glass-molded substrate B1 is cut out at a pitch E1. As shown in FIG. 4B, the cut out substrate Bl is formed with an external winding groove Bla and an internal winding groove Blb, and a gap surface is processed.

Then, a pair of substrates B1 with external winding grooves Bla and internal winding grooves Bib formed therein are prepared, and they are butted and fixed under pressure so that their gap surfaces face each other, and the low melting point glass 2 is bonded. The core block 8 is obtained by raising the temperature to such a temperature as to give strength and performing glass welding to obtain a core block 8 as shown in FIG.

This core block 8 is cut at a constant width to obtain a head chip body 10 as shown in FIG. 3(a).

Next, this head chip body 10 is immersed in a neutral potassium nitrate solution for about 20 hours to perform ion exchange treatment on the low melting point glass 2 containing sodium. By ion exchange, monovalent ions with a small volume in the low melting point glass 2 are replaced with monovalent cations with a large volume. That is, as shown in FIGS. 4(a) and 4(b), small sodium ions (Na") are exchanged with large potassium ions (K"), and the low melting point glass 2 containing sodium is exchanged with large potassium ions (K") in the Helad chip body 10. As shown in FIG. 3(b), the glass changes to a low melting point glass 2' containing potassium.

Then, the head chip body 10 subjected to ion exchange is subjected to processes such as tape sliding surface polishing, coil winding, and fixing to a base plate to obtain a magnetic head.

According to the above configuration, since the low melting point glass 2 containing sodium is used until the head chip body 10 whose glass welding is completed is obtained, the ease of vitrification of the low melting point glass 2 can be effectively brought out. High reliability of welding and ease of processing can be achieved. Then, after entering the stage where vitrification does not need to be considered, ion exchange treatment is performed, and as this ion exchange treatment exchanges small sodium ions with large potassium ions, the tensile stress in the glass increases. Glass strength can be improved. In addition, glass containing potassium has high hardness (in the case of this example, the Pinkers hardness before ion exchange was 350, but the Vickers hardness after ion exchange improved to 600), and has high wear resistance. Since the magnetic head has high properties such as water resistance, water resistance, and chemical resistance, the life of the magnetic head having the low melting point glass 2' containing potassium is significantly increased.

[Effects of the Invention] As described above, the method for manufacturing a magnetic head according to the present invention has the following steps.
A process of forming a soft magnetic thin film with a predetermined film thickness on one side wall surface of the substantially ■-shaped multi-grooves formed on the substrate surface, and butting a pair of substrates on which this soft magnetic thin film has been formed. The method for manufacturing a magnetic head includes a step of welding low-melting point glass with the welded glass, and includes a step of subjecting the low-melting point glass to an ion exchange treatment after welding.

As a result, it is possible to simplify the manufacturing of magnetic heads by using low melting point glass before welding, such as glass containing sodium, which is easy to vitrify and has excellent weldability and workability. By using ion exchange treatment, welded glass is changed into, for example, potassium-containing glass, and the potassium-containing glass has the advantages of high hardness, high abrasion resistance, high water resistance, and high chemical resistance, as well as high strength. This has the effect that the magnetic head can have the advantages of the above, and the life of the magnetic head can be extended.

[Brief explanation of drawings]

1 to 4 show one embodiment of the present invention. 1(a), 1(b) and 1(d) to 1(f) are cross-sectional views showing each step of the magnetic head manufacturing method from groove processing to glass molding, and FIG. 1(c) is a vacuum evaporation method. FIG. 3 is an explanatory diagram showing the flying direction of vapor deposited particles in the case of FIG. FIGS. 2A to 2C are perspective views showing each step of the magnetic head manufacturing method from cutting out a glass-molded substrate to obtaining a head block. FIG. 3(a) is a perspective view showing the head chip body before ion exchange, and FIG. 3(b) is a perspective view showing the head chip body after ion exchange. FIG. 4(a) is a schematic diagram showing the state of glass containing sodium before ion exchange, and FIG. 4(b) is a schematic diagram showing the state of glass containing potassium after ion exchange. 5 to 7 show conventional examples. FIGS. 5A to 5C are cross-sectional views showing each step of the magnetic head manufacturing method from groove processing to glass molding and molding. FIGS. 6(a) and 6(b) are perspective views showing each step of the magnetic head manufacturing method from cutting out a glass-molded substrate to obtaining a head block. FIG. 7 is a perspective view of the Herad tip body. 1 is a photosensitive crystallized glass, 2 is a low-melting glass containing sodium, 2' is a low-melting glass containing potassium, 3 is a soft magnetic thin film, 4 is a non-magnetic oxide film, 5 is a metal Ti film, 6 is a metal Cr 7 is a groove, and 10 is a helad tip body.

Claims (1)

[Claims] 1. A step of forming a soft magnetic thin film with a predetermined thickness on one side wall surface of each substantially V-shaped groove formed on the substrate surface; A method for manufacturing a magnetic head comprising a step of butting together a pair of formed substrates and welding them with low melting point glass, characterized by comprising a step of subjecting the low melting point glass after welding to an ion exchange treatment. A method of manufacturing a magnetic head.