JPH0383207A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To prevent generation of bubbles or vacancies during the glass filling process in a head core block groove comprising ferromagnetic metal material by forming a nonmagnetic iron oxide film on the inner wall of the track groove so as to prevent reaction of 'Sendust(R)' and glass and then filling the groove with glass. CONSTITUTION:A nonmagnetic alpha-Fe2O3 film 91 is formed by sputtering, etc., on the inner wall of the track groove 69 to be filled with glass 70 and then the groove 69 is filled with glass 70. Preferable sputtering conditions to form the film 91 are at 1.0Pa (pascal) atmosphere, proportion of flow rates 90% Ar and 10% O2, electric power 5W/cm<2>, and 5,000 - 10,000Angstrom film thickness. By providing the film 91 between the glass 70 and 'Sendust(R)' to prevent direct contact of glass and 'Sendust(R)', reaction of these is prevented. Since the film 91 has good wettability with glass 70, no bubble nor vacancy appears during the glass filling process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a magnetic head used in information recording and reproducing devices such as video tape recorders (VTRs) and digital audio recorders (DATs).

[Conventional technology]

Magnetic tapes used in conventional consumer VTRs generally use iron oxide recording media, but 8mmV
Magnetic recording devices with high recording densities, such as TR and DAT, are being improved in quality by using metal-based recording media with high coercive force.

In order to bring out the full characteristics of a magnetic tape, it is generally said that the saturation magnetic flux density (hereinafter referred to as B) of the head material needs to be at least five times the coercive force (hereinafter referred to as H) of the tape. Iron oxide H is approximately 600 (Oe)
In the case of metal tape, it is approximately 1400 (Oe).

In contrast, the B of oxide magnetic material (ferrite), which is the magnetic head material used in consumer VTRs, is approximately 50.
Since it is 00G, it is more than 5 times and sufficient for cheap iron oxide tape, but it is less than 5 times for metal tape, so to bring out its characteristics, 1400 x 5 = 7000. 7000G
The above B is required. Therefore, metal magnetic materials with high B (such as Sendust) have come to be used as magnetic head materials.

The first magnetic head using this type of sendust is
The structures shown in FIGS. 5(a) and 5(b) are known.

The magnetic head shown in the figure is called a "bulk type head", and track width regulating grooves are formed before the head core halves la and 1b are joined together, and then a glass plate is placed in the track width regulating grooves. The structure is filled with.

However, in order to manufacture this bulk type head, tracks are processed on the core halves 1a and 1b before the gap is formed, so a high precision technique is required when welding the core halves ia and 1b together. I have to do track matching.

Therefore, a magnetic head has been proposed that can omit the track alignment process that is necessary in the bulk type head (see FIGS. 14(a) and 14(b)).

The entire width of this magnetic head is a track, so
This AT head is called an all-track head (hereinafter referred to as an AT head), and as shown in FIGS. 14(a) and 14(b), this AT head has a pair of head core halves 10a and 10b welded together, The track width regulating groove 12 forming the track width regulating groove 12 is filled with glass 13, and this glass 13 is exposed on the tape sliding surface.

[Problem to be solved by the invention]

Among the above-mentioned magnetic heads, for example, when manufacturing the above-mentioned bulk type head, as shown in FIG.
Bar-shaped head core block halves 61a and 61b, which have been tracked in advance, are welded to each other and track aligned to form a track groove 3, and this track groove 3 is filled with glass.

Heads using ferrite have good so-called "wettability" between iron oxide and glass, so there are no problems when filling the glass, but in heads made of Sendust, Sendust has better wettability with glass than ferrite. In addition, since a reaction occurs between the sendust and the glass, air bubbles 5 may be generated in the glass 4 filled in the track groove 3, as shown in FIG. There were problems such as the occurrence of unfilled portions, so-called blanks 6. Note that there is a track 7 between adjacent track grooves 3.
is formed, and numeral 8 is a magnetic gap.

The present invention has been made to solve such problems, and provides a method for manufacturing a magnetic head that can satisfactorily fill track grooves with glass and that does not adversely affect electromagnetic conversion characteristics. The purpose is to obtain.

[Means to solve the problem]

A method of manufacturing a magnetic head according to the present invention includes a step of filling track grooves of a head core block made of a ferromagnetic metal material with glass. After forming the iron film, the track grooves are filled with glass.

[Effect]

In the present invention, the non-magnetic iron oxide film formed on the inner surface of the track groove acts as a reaction prevention film that prevents the reaction between sendust and glass, so that bubbles, droplets, etc. do not occur.

〔Example〕

A first embodiment of the present invention will be described below with reference to the drawings. 1 to 12 show a method of manufacturing a bulk type head among Sendust magnetic heads.

To explain the outline of this manufacturing method, first, the second
As shown in the figure, a pair of rod-shaped materials 61 made of Sendust, a ferromagnetic metal material, and having a rectangular cross section have a groove 6 for a winding window.
2, a groove 63 around the winding frame is formed to form a head core block half 61b (Fig. 3), and a groove 64 around the winding frame is formed in the other material 61 to form a head core block half 61b. 61
Let it be a. Next, after forming track grooves 66 and 67 on the joint surfaces 65 of each block half body 61a and 61b (FIG. 4), the joint surfaces 65 of each block half body 61a and 161b are mirror polished (FIG. 5). Block half 61a16
A gap spacer 68 is formed by electron beam evaporation of 3 layers of AI O-S i 02 etc. on the bonding surface 65 of 1b (
Figure 6). Next, the head core block 61 having the track groove 69 is formed by aligning the tracks of each of the block halves 61a161b and joining them by silver solder welding (FIG. 7). A film 91 of iron (α-Fe203) is formed by sputtering to a thickness of 5,000 to 10,000 thick from the sliding surface 100 side (the track-processed side) of the head core block (see FIG. 12).

The α-Fe203 film covers the entire sliding surface, and unnecessary portions are removed during R polishing. In FIG. 12, broken lines indicate the outer shapes of the core block and track grooves before forming the α-Fe203 film.

After that, the track groove 69 is filled with glass 70 (
FIG. 8(a),(b)). Here, the same figure (a) shows the state before glass filling, in which the bar-shaped glass 70 before melting is inserted into the wire-wound window groove 62, and the same figure (b) shows the state where the bar-shaped glass 70 is heated. It shows a state in which it is melted and filled into the track groove 69. Next, after performing R polishing to form an R shape (a curved surface shape such as an arc shape) on the tape sliding surface 71 (FIG. 9), the head core block 61 is rotated at a predetermined angle in a direction intersecting the elongated direction. A head chip 81 is formed by slicing (FIG. 10), and then this head chip 81 is attached and fixed to a head base 82 (FIG. 11). In addition, in FIGS. 4 to 9, the grooves 66, 67.
69 and the filled glass 70 are partially omitted and shown by chain lines.

Next, the characteristics of the glass filling process in this example are as follows:
The explanation will be made based on FIG. 1 (this figure corresponds to FIG. 17). In this embodiment, a film 91 of non-magnetic iron oxide (α-Fe203) is formed on the inner surface of the track groove 69 filled with glass using a film forming apparatus such as sputtering, and then the glass 70 is
The track groove 69 is filled with. The sputtering conditions for forming such a film 91 are preferably as follows.

(1) Atmosphere ○ Pressure...1. OPa (Pascal) (2) Power 5 (W/cd) (3) Film thickness of a-F e 203 5000-1000 people Therefore, in this example, the film 91 of α-F e 203 is the same as the glass 70. The α-F e 203 film 91 is interposed between the glass and the sendust and acts as a reaction prevention film that prevents the reaction by cutting off contact between the glass and the sendust. Since the wettability is good, no bubbles or droplets are generated when the glass 70 is filled, and no defective magnetic heads are produced. Further, since the α-Fe 203 film 91 is non-magnetic, it does not adversely affect electromagnetic conversion characteristics.

Next, as a second embodiment of the present invention, an AT head will be described based on FIGS. 13(a) to 13(Cf').

First, a groove 62 for the winding wire and a groove 63 around the winding frame are formed in a pair of rod-shaped materials 61, and the head core block half-closed 61b is formed.
Then, on the other material 61, a 11E64 around the winding frame is formed to form a head core block half 61a (see FIG. 13).
a)). Next, the joint surface 65 of each block half body 61a, 61b is mirror polished, and then each block half body 61a,
A gap spacer 68 is formed by electron beam evaporation of Al2O3, 5i02, etc. on the bonding surface 65 of 61b (13th
Figure (b)). Next, the head core block 66 is formed by welding each block half body 61a161b with silver solder (FIG. 13(c)), and then the track 101 is formed by forming the track groove 69 (FIG. 13(c)).
Figure (d)). Furthermore, after this, a non-magnetic iron oxide (α-Fe203) film 91 is coated on the inner surface of the track groove 69 to a thickness of 5,000 to 10,000 layers from the tape sliding surface side of the head core block (the side where the track processing is applied). It is formed by sputtering. The sputtering conditions are the same as in the first embodiment. Thereafter, the track groove 69 is filled with glass 70. Next, after performing R polishing to form an R shape on the tape sliding surface 7 (FIG. 13(e)), a sliding surface processing groove 102 is formed on the sliding surface 71 (FIG. 13(f)). . Thereafter, the head core block is sliced at a predetermined angle in a direction crossing the longitudinal direction to obtain the Herad chip shown in Fig. 4.

Therefore, in this second embodiment as well, after track machining is completed, on the inner surface of the track groove 12 (FIG. 14(a)),
Form a non-magnetic iron oxide film (α-Fe203 film),
If the track grooves 12 are then filled with glass 13, the same effects as in the first embodiment can be obtained.

〔Effect of the invention〕

As explained above, the present invention has a structure in which, on the inner surface of the track groove,
After forming a non-magnetic iron oxide film, glass is filled into the track grooves, so the film acts as a reaction prevention film to prevent the reaction between sendust and glass. No bubbles, voids, etc. are generated, and the electromagnetic conversion characteristics are not adversely affected.

[Brief explanation of drawings]

FIG. 1 is an enlarged plan view of a head core block showing a first embodiment of the present invention, and FIGS. 2 to 12 are views sequentially showing manufacturing steps of a bulk type magnetic head in the same embodiment. 7 is a perspective view, FIGS. 8(a) and 8(b) are side views showing the glass filling procedure, FIGS. 9 to 11 are perspective views,
Fig. 2 is a plan view showing the state after the α-Fe203 film is attached, and Figs. 13(a) to 13(f) are views sequentially showing the manufacturing process of the AT head. Figure 14(b) is a plan view, Figure 14(C) is a perspective view, Figures (cL) to (f) are plan views, and Figures 14(a) and (b) are a plan view and front view of the AT head, respectively. 15(a) and 15(b) are respectively a plan view and a front view of a bulk type head, FIG. 16 is an enlarged perspective view of a head core block when manufacturing a bulk type head, and FIG. 17 is an enlarged perspective view of a head core block when manufacturing a bulk type head. , is an enlarged plan view of a head core block showing the prior art. 2.13.70...Glass, 12.69...Track groove, 21, 1...Helad core block, 1...Membrane.

Claims (1)

[Claims] In a method for manufacturing a magnetic head that includes a step of filling glass into a track groove of a head core block using a ferromagnetic metal material, a non-magnetic iron oxide film is formed on the inner surface of the track groove, and then glass is filled into the track groove. A method of manufacturing a magnetic head, characterized by filling track grooves.