JPS63173211A - Manufacture of magnetic head - Google Patents

Abstract

PURPOSE:To prevent the vicinity of the magnetic gap formed surface from being oxidized, and to obtain an excellent electromagnetic conversion characteristic by forming a gap film in advance on at least the magnetic gap formed surface of magnetic core half bodies, and executing glass welding, in a state that a magnetic core is protected by the gap film. CONSTITUTION:At the time of preparing a magnetic head by joining as one body a pair of magnetic core half bodies 1 consisting of a ferromagnetic material by glass welding, a gap film 3 is formed in advance on at least a magnetic gap formed surface 1a of each magnetic core half body 1 by a vacuum thin film forming technique, and thereafter, glass welding is executed in an inert gas atmosphere containing oxygen. In such a way, since glass welding is executed after the gap film 3 has been formed, the magnetic gap formed surface 3 is protected from atmospheric gas by the film 3. Accordingly, it does not occur that the vicinity of the magnetic gap formed surface 1a is oxidized, and when glass welding is being executed in an inert gas atmosphere containing oxygen, the generation of glass foam can be prevented. In such a way, the reliability and the electromagnetic conversion characteristic are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a magnetic head, and more particularly to a method for forming a gap in a magnetic head using a ferromagnetic material that is easily oxidized in the magnetic core.

C. Summary of the Invention] The present invention provides a magnetic core halves made of a ferromagnetic material (both of which have a gap film formed on the magnetic gap forming surface, and which are glass-fused in an inert gas atmosphere containing oxygen). This is intended to prevent the generation of glass bubbles and oxidation of the magnetic core halves that occur during the above-mentioned glass fusion, and to improve reliability and electromagnetic conversion characteristics.

[Conventional technology]

Conventionally, a magnetic head mounted on a magnetic recording/reproducing device such as a VTR (video tape recorder) has a pair of magnetic core halves (51) and (52) made of, for example, Mn-Zn ferrite, as shown in FIG. The contact surfaces of these magnetic core halves (51) and (52) are defined as a magnetic gap g. Furthermore, track width regulating grooves (53) and (54) are cut out at both ends of the magnetic gap to regulate the track width T- of the magnetic gap g. and,
The above track width regulation? Glass (55) is melted and filled within n (53) and (54) and between the magnetic gap forming surfaces (51a) and (52a).

To create this type of magnetic head, a pair of magnetic core halves (51) and (52) provided with track width regulating grooves (53) and (54), respectively, are connected to a magnetic gap forming surface (51a), (52a) are made to face each other so as to butt each other and are combined by glass fusing. Then, during this glass fusion, the trunk width regulating groove (53), (
54) inner and magnetic gap forming surfaces (51a), (5
2a) A glass (55) is filled between the two. That is,
The fused glass serves as a gap material for the magnetic gap g, forming the magnetic gap g having a gap length i.

Generally, the above-mentioned glass fusing is performed in an inert gas atmosphere, such as nitrogen gas or argon gas.

[Problem that the invention seeks to solve]

By the way, when glass fusion is performed using these atmospheric gases, there is an unavoidable drawback that so-called glass salts are generated in the glass (55) after the fusion. These glass bubbles are caused by the reaction between carbides and fused glass that occur during high-temperature heat treatment such as glass fusion, or by the magnetic gap forming surface (51
a), (52a) and track width regulation groove (53),
(54) This occurs due to the wettability of the surface (hereinafter referred to as the magnetic core surface), reducing the reliability of the head.

In particular, the magnetic core half (51).

In order to ensure the bonding strength of (52), when a fused glass with a high softening point temperature is used, the generation of the above-mentioned glass bubbles becomes noticeable.

Under these circumstances, in order to eliminate the above-mentioned glass bubbles, a small amount of oxygen is mixed into an inert gas, and the organic matter that is generated when the temperature rises is combusted without being carbonized, resulting in the generation of glass bubbles due to the reaction between the glass and the carbide. A method has been considered in which the wetting angle between the glass (55) and the magnetic core surface is improved by oxidizing the magnetic core surface, thereby improving the wetting property and preventing the generation of glass bubbles.

However, when the magnetic core surface is oxidized as mentioned above,
This oxidized part is covered with T-hematite (
h) occurs. In this way, the magnetic core half (51),
Since the T-hematite (h) generated in (52) has an adverse effect on the electromagnetic conversion characteristics of the magnetic head, it is desired to improve this.

The present invention has been proposed in view of the conventional situation, and provides a magnetic head that prevents the generation of glass bubbles during glass fusing and oxidation of the magnetic core half, and has excellent reliability and electromagnetic conversion characteristics. The purpose is to provide a manufacturing method for.

[Means for solving problems]

In order to achieve the above-mentioned object, the method for manufacturing a magnetic head of the present invention includes a method for manufacturing a magnetic head, in which a pair of magnetic core halves made of a ferromagnetic material are joined together by glass fusion to create a magnetic head. This method is characterized in that a gap film is previously formed on at least the magnetic gap forming surface of the half body by a vacuum thin film forming technique, and then glass is fused in an inert gas atmosphere containing oxygen.

[Effect]

In this way, since the gap film is previously formed on at least the magnetic gap forming surface of each magnetic core half and then glass fused, the magnetic gap forming surface is protected from the atmospheric gas by the gap film. .

Therefore, the vicinity of the magnetic gap forming surface will not be oxidized.

Further, since glass fusion is performed in an inert gas atmosphere containing oxygen, generation of glass bubbles can be prevented.

〔Example〕

Hereinafter, an embodiment of a method for manufacturing a magnetic head to which the present invention is applied will be described with reference to the drawings.

To create a magnetic head according to this embodiment, first, the first
As shown in the figure, on the main surface of the substrate (1) made of a ferromagnetic material, that is, on the joint surface when the magnetic core halves are brought together, a track width having a substantially semicircular cross section is formed by mechanical means such as a rotary grindstone. A plurality of regulating grooves (2) are formed over the entire width. Here, the flat surface (1) between adjacent trunk width regulating grooves (2)
a) corresponds to the magnetic gap forming surface.

As the substrate (1), any material can be used as long as it is normally used as a magnetic core material, but the present invention particularly uses a magnetic material that is easily oxidized.

For example, it is suitable when using an oxide magnetic material such as Mn-Zn ferrite or Ni-Zn ferrite.

Next, as shown in FIG. 2, the track width regulating groove (
A gap film (3) having a predetermined thickness was deposited on the entire negative main surface of the substrate (1) including the substrate (2) using a vacuum thin film forming technique, and this was used as a core block (5).

Here, the gap film (3) is formed to have a film thickness t of at least 50 Å or more in order to prevent the substrate (1) from being oxidized and deteriorating its magnetic properties during glass fusion, which will be described later. However, it goes without saying that the upper limit of the above 1]9FJt should be 2 or less of the gap length of the obtained magnetic head [shown in FIGS. 5(A) and 5(B)].

In addition, the material for the gap film (3) should not react with the glass during glass fusion of the magnetic core halves, and should not react with the substrate (
Sio
Z+Tazos+Zro*, Cr, Be-Cu alloy, etc. are suitable.

Furthermore, the method for attaching the gap film (3) is as follows:
Examples of vacuum thin film forming techniques include vacuum evaporation, sputtering, ion blating, cluster ion beam, and the like.

In this embodiment, the gap film (3) is formed by adhering to the gear forming surface (1a) and the inner wall of the track width regulating groove (2). It suffices if it is formed on the magnetic gap forming surface (la), and does not necessarily need to be formed on the inner wall of the trunk width regulating groove (2).In this way, the magnetic gap forming surface (1a)
In order to form the gap film (3) only on the substrate, a gap film of a predetermined thickness may be deposited on the entire surface of the substrate in advance, and then track width regulating grooves may be cut and formed.

Next, of the pair of core blocks (5), (5) created through the above steps, one core block (5
), as shown in Figure 3, the trunk width regulating groove (2
), an S wire 'a (6) for winding a coil conductor and a fusion groove (7) were cut to form a core block (8).

That is, in this embodiment, both core blocks (5),
(8) has a gap film (3) adhered to the magnetic gap forming surface (1a) and the inner wall of the trunk width regulating groove (2).

Subsequently, as shown in FIG. 4, a core block (5) on which a gap film (3) is formed, a winding 1t (6) and a fused/g (7) on which a gap film (3) is formed. The core blocks (8) having been cut are butted against each other so that the magnetic gap forming surfaces (la) and (la) face each other. Thereafter, a glass rod (not shown) is placed in the welding groove (7), and then the glass rod is melted in a high temperature furnace to join both head blocks (5) and (8). As a result, the molten glass (9) moves into the track width regulating groove (2).
), (2) is filled with both blocks (5), (
8) are combined. Then, the magnetic gap forming surface (la
) gap D! (3) In (3), a magnetic gap g having a gap length and a track width indicated by T- is formed.

The glass (9) used for this glass fusion is preferably one having a softening temperature of 400° C. or higher from the viewpoint of bonding strength. For example, as a glass with a softening temperature of 400°C or higher, Si0□15 to 40% by weight, Nazo 0 to
20% by weight, Bz (h 10-20% by weight, f120
i5-20 weight%, ZnO0-20% by weight, PbOO~
Silicon-sodium glass (softening temperature 500-700°C) with a composition of about 40%, PbO50-8
0% by weight, thoz 10~20%, ZnOO~1
0% by weight, B102O~20% by weight, AIzOz 0~
15% by weight, Sing O ~ 10 weight%, NazOO ~
Examples include lead-boron glass (softening temperature 350 to 500°C) having a composition varying by about 10x4%. Specifically, Si0□40% by weight, Nazo 20% by weight, B! 0
320% by weight, AhOi 10% by weight, ZnO10
Silicon-sodium glass with a composition of % by weight, or 60% by weight of PbO, 1% by weight of Bt(1+15% by weight, Z
nO 10% by weight, B10 15% by weight, ^hOz 10
A lead-boron glass having a composition of 4% by weight is preferred.

Moreover, the above-mentioned glass fusing is performed by increasing the temperature in an inert gas atmosphere containing a predetermined amount of oxygen.

Here, the amount of introduced oxygen is preferably controlled within the range of 10 to 500 ppm, and the amount of introduced oxygen is 10 ppm.
Below a+, it is difficult to control glass bubbles;
If the temperature exceeds pm, damage (oxidation, etc.) to exposed parts of the substrate (1) other than the magnetic gear becomes significant, resulting in deterioration of electromagnetic conversion characteristics.

Further, as the inert gas, nitrogen gas, argon gas, etc. are used.

By mixing oxygen into the inert gas in this way, organic matter generated when the temperature rises can be burned without carbonizing, so the generation of glass bubbles due to the reaction between molten glass and carbide can be prevented. At the same time, gap Il! (2
) can also prevent glass bubbles from forming due to its good wettability.

Further, since a gap film (2) is adhered to the boundary between the substrates (5), (8) and the glass (9) so as to cover the substrate (1), the substrate (1) is Gap film (3
), there is no fear of oxidation, and therefore the magnetic properties of the substrate (1) are ensured.

Therefore, according to the present invention, even if high melting point glass is used as the fusion glass, the substrate (1) will not be oxidized or glass bubbles will be generated, so the strength of the bonding is high, and TiTa A magnetic head with excellent conversion characteristics can be created. Therefore, the present invention is effective when applied to devices such as VTRs where the relative speed between the magnetic recording medium and the magnetic head is high and the mechanical strength (particularly the bonding strength) of the magnetic head is limited.

Finally, after cutting at the cutting positions indicated by line A-A, line A'-A', and line B-B in FIG. Then, cylindrical polishing is performed to complete the magnetic head shown in FIGS. 5(A) and 5(B).

In this magnetic head, gap films (3), (
3) is formed, and the gap length of the magnetic gap g is regulated by the total film thickness of the gap films (3) and (3). Furthermore, the magnetic gap g is formed by the trunk width regulating grooves (2), (2).
- is regulated, and the track width regulation control (2), (2
) is filled with glass (9) to ensure contact characteristics with the magnetic recording medium and to bond both magnetic core halves together.

In this example, the gap length of the magnetic gap g is determined by a gap film (3) formed in advance on both magnetic core halves (1).
, (3) is regulated by the film thickness, but by interposing the glass at the time of glass fusion between the gap films (3), (3), the gap films (3), (3) and the fused The length of the gap may be regulated by the attached glass.

Also in this case, the vicinity of the magnetic gap forming surface (1a) is not oxidized, and a magnetic helad with good electromagnetic conversion characteristics can be provided.

In this way, in the present invention, the gap film (
2) was formed using vacuum thin film forming technology.
) and (8) because the glass is fused by butting them together, even if oxygen is mixed into the atmospheric gas to suppress the generation of glass bubbles, the oxygen will penetrate into the surface of the substrate (1) and cause the substrate to deteriorate. (1) will not be oxidized. In particular, when ferrite is used for the substrate, γ-hematite is not generated and good electromagnetic conversion characteristics can be ensured.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment and can be applied to magnetic heads of various structures without departing from the spirit of the present invention.

For example, in the above embodiment, a magnetic head in which the magnetic core half is made of a single ferrite was described, but in addition to this,
Most of the magnetic core half is made of ferrite, etc., and a magnetic alloy thin film such as Fe-A1-3i alloy is formed on the abutting part of the magnetic core half, and the abutting part of the magnetic alloy FBI film is The present invention can also be applied to a magnetic head compatible with high coercive force magnetic recording media configured as a magnetic gear knob. That is, the present invention
Materials that are easily oxidized at one or more locations on the joint surfaces of the magnetic core halves (
For example, it is suitable for application to a magnetic head having a structure in which ferrite is exposed.

〔Effect of the invention〕

As is clear from the above description, in the present invention, a gap film is formed in advance on at least the magnetic gap forming surface of the magnetic core half, and with the gear knob film protecting the magnetic core,
Since glass fusion is performed, even if the glass fusion is performed in an oxygen-containing inert gas atmosphere, the vicinity of the magnetic gap forming surface will not be oxidized. Therefore, the magnetic head has excellent electromagnetic conversion characteristics.

At the same time, since the glass fusion is performed in an oxygen-containing inert gas atmosphere as described above, the generation of glass bubbles can also be reduced.

Therefore, since it is possible to use highly reliable high melting point glass as the glass for the above-mentioned fusion, it has excellent bonding strength,
In addition, a magnetic head with excellent electromagnetic conversion characteristics can be provided.

Furthermore, the present invention can be realized without major changes to conventional manufacturing methods, and its practical value can be said to be extremely high.

[Brief explanation of the drawing]

1 to 4 are schematic perspective views showing the method of manufacturing a magnetic head according to the present invention according to the process order;
The figure shows the process of forming trunk width regulating grooves, Fig. 2 shows the process of forming gap films, Fig. 3 shows the process of forming winding grooves and fusing grooves, and Fig. 4 shows the glass fusing process. . 5(A) and 5(B) show a magnetic head made according to the present invention, FIG. 5(A) is a schematic perspective view, and FIG. 5(B) is a magnetic recording medium. FIG. 3 is a plan view of main parts showing a contact surface. FIG. 6 is a plan view of essential parts showing a surface of a conventional magnetic head that faces a magnetic recording medium. 1...Substrate (magnetic core half) 1a...Magnetic gap forming surface 2...Track width regulating groove 3...Gap film 5.8...Core block Figure 1 Ya... Nobu Moan's dryness and current relationship are shown in Fig. 2. ) 乍ε 燆 の super smoky head Figure 6 Procedural amendment stamp button March 5, 1988 Commissioner of the Patent Office Black 1) Akio Yu 1, Indication of the case 1985 Inter-patent No. 003455 2, Invention Name: Magnetic head manufacturing method 3, relationship with the amended person case Patent applicant address: 6-7-35, Kitashinyo, Tokyo Parts Store Name (2)
18) Sony Corporation Representative Nori Ohga Voluntary Motion 7. On page 1O, line 1O of the Statement of Contents of Amendment, the statement "rBiO□" is corrected to rBiz(hJ. The description "rBiO "Gap film (3)
” he corrected. From line 19 of page 13 of the specification to line 20 of the same page, the description "substrate (1)" has been replaced with "core block (5), (
8) Correct it as J. The description "Substrate (1)" on page 13, line 20 of the specification is corrected to "Core block (5), (8) J."(that's all)

Claims (1)

[Claims] When a pair of magnetic core halves made of ferromagnetic material are bonded together by glass fusion to create a magnetic head, a vacuum thin film is formed in advance on at least the magnetic gap forming surface of each of the magnetic core halves. A method for manufacturing a magnetic head, which comprises forming a gap film using a technique, and then fusing glass in an inert gas atmosphere containing oxygen.