JPS63214906A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To improve mass productivity and reliability by molding glass in grooves on a substrate and removing the excess glass, then forming a magnetic metallic material film thereon, laminating plural sheets of such substrates, subjecting the laminate to high-temp. welding by glass, and cutting and polishing the laminate to a prescribed size, thereby obtaining pieces. CONSTITUTION:Grooves for packing the glass are worked to the ferromagnetic substrate 1 and the welding glass 3 is molded therein. The excess glass is removed by polishing. The rear of the substrate 1 is subjected to the same working. The groove and mold glass are then applied on both faces of the substrate 1 and a laminate 23 consisting of the magnetic metallic material and insulator is formed on one face thereof. Some sheets of such substrates are laminated and the subjected to the high- temp. welding. The laminate is cut to the prescribed size to obtain the pieces 6. Such pieces are polished on the side to be formed as a gap surface. The pieces which is deposited with a gap material on the gap surface and is notched with a winding groove from the piece 6 on the other side is formed. These two pieces are butted to each other on the gap surface and the subjected to the high-temp. welding by the welding glass 3. A magnetic head which has high performance even if the recording frequency is several tens MHz is thereby obtd. with the high productivity.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic head suitable for high-density magnetic recording,
In particular, the present invention relates to a magnetic head for use in VTRs, etc., which has performance suitable for recording and reproducing on high coercive force media, and also has performance suitable for high recording frequencies of several tens of MHz.

[Conventional technology]

In recent years, with the increase in the density of magnetic recording, in order to sufficiently record on high coercive force media such as metal tapes, the magnetic material near the gap has to be replaced by ferrite, which is opaque and has a high saturation magnetic flux density (sendust, amorphous, permalloy). It is necessary to use However, since these have low electrical resistivity, if the entire head core is made of magnetic metal, the V
Even at a recording frequency of several MHz, which is the recording frequency of TR, etc., the eddy current loss is large and it cannot be used.

Therefore, a composite magnetic head is generally used.

A conventional example will be explained using the Japanese Patent Publication No. 59-2224 as an example.

FIG. 12 is an external perspective view of the composite magnetic head. In the figure, (61) is the pseudo gap length, (62), (63) are the auxiliary core made of ferromagnetic oxide, (64) is the main core made of metal magnetic material, (10) is the gap, (66), (
68) is glass, and (67) is a winding groove. As shown in FIG. 13, the method for manufacturing such a composite magnetic head is to bond the main core (64) and one of the auxiliary cores (62) with an organic adhesive, and then polish the main core to reduce its thickness. is thinned until it reaches a predetermined track width (69) (see FIG. 14).

Then, as shown in FIG. 14, the other auxiliary core (63) is fixed with an organic adhesive. Note that (65) is a pseudo gap. Both the main core and the auxiliary core are made using almost the same process as the current ferrite for VTRs.

[Problem that the invention seeks to solve]

In the conventional composite magnetic head as described above, not only the main core and the auxiliary core must be made separately, but also the main core and the auxiliary core must be glued one by one, which makes it completely unsuitable for mass production. Additionally, organic adhesives tend to leave gaps between the main core and the auxiliary core as they age, and the binder of the magnetic tape can clog them, which also poses reliability problems. Since eddy current loss occurs corresponding to the thickness of the main core, there is a problem in that it cannot handle higher frequencies.

This invention was made to solve the above-mentioned problems. It can be manufactured in large quantities using thin film formation technology, making it highly suitable for mass production. Moreover, since all joints are made of glass, it is highly reliable. .

Furthermore, since the portion corresponding to the main core can be made of a laminated layer of a metal magnetic material and an insulator, eddy current loss proportional to the square of the thickness can be suppressed, and high recording frequencies of several tens of MHz can be supported.

[Means for solving problems]

The manufacturing method of the magnetic head is to process glass grooves on the substrate.
After molding glass into the groove and removing the excess glass, a metal magnetic film is formed on top of it, and multiple sheets of these are stacked and welded at high temperature by the glass molded into the groove, and then cut into a predetermined size using a cutting machine. Then, you can obtain a core half order and/or piece.

[Effect]

In this invention, there is no need to create the auxiliary core and the main core separately and fix them one by one with an organic adhesive.
It has excellent mass productivity, and since the joints are made only by glass welding, there are no gaps and the reliability is high.

〔Example〕

FIG. 1 is a cross-sectional view showing one embodiment of the present invention.
) is a ferromagnetic substrate such as Mn-Zn ferrite.

8(2) for glass filling is processed on this using a wheel or the like.

Next, the fused glass (3) is molded as shown in FIG. 2, and excess glass is removed by polishing. Apply this also to the back of the substrate (1).

FIG. 3 shows a substrate (1) with grooves and molded glass on both sides.

FIG. 4 shows the structure shown in FIG. 3 in which a laminate (23) of a metal magnetic material (4) and an insulator (5) is formed on one side by a method such as sputtering. The thickness of the laminate (23) corresponds to the track width.

Figure 5 shows a stack of several of the substrates made in Figure 4 and welded at high temperature (it goes without saying that these substrates 1 are joined only at the groove 2 where the welded glass 3 is located). Nor). The product thus produced is cut into predetermined dimensions as shown by broken lines to obtain pieces (6). Polish the side that will become the gap surface.

The resultant product is shown in FIG. In the figure (7
) is the gap surface. Gap material (9) is stacked on this surface as shown in FIG.

On the other hand, a piece in which a winding groove (8) is cut as shown in FIG. 7 is formed from the piece (6) in FIG. 5.

The piece shown in Fig. 6 and the piece shown in Fig. 7 are paired, and as shown in Fig. 8, the two pieces are butted at the gap surface (7) and welded at high temperature using the welding glass (3). . In addition, since the gap material (9) is a very thin layer, the gap material (9) between the welded glasses that are butted together is
does not pose an obstacle to high-temperature welding of glass (31).

FIG. 8 is a perspective view showing what is thus obtained. This is further cut as shown by the broken line.

In FIG. 9, the original shape obtained by cutting the one in FIG. 8 is shown in dotted lines, and the one obtained by polishing and made thinner is shown in solid lines.

In FIG. 9, the gap material (91) for forming the gap (10) is included in the welding glass (3) at the portion where it fuses with the welding glass (3), and is shown without distinction.

A composite magnetic head is thus obtained. Of course, it will be clear from the diagram in FIG. 9 that it can be processed into a desired contour shape. In order to obtain a head with an initial azimuth angle, the welded block may be cut at an angle corresponding to the azimuth angle.

When such a manufacturing method is used, the larger the substrate (1) is, and the more the substrates are stacked, the more head chips can be obtained at one time, and the greater the productivity. Furthermore, since all bonding is done using fused glass, reliability is high. In addition, the metal magnetic material is
Since it is made of
! Even if the recording frequency is compatible with the digital VTR1 high-quality VTRIC, it can be used satisfactorily.

In the above embodiment, a ferromagnetic oxide is used for the substrate (1), but a nonmagnetic material may be used. Particularly in the case of a high recording frequency of several tens of MHII, it is necessary to reduce the inductance, so a non-magnetic material may be preferable.

Further, when the metal magnetic material is used at a relatively low frequency, even a single layer of the metal magnetic material film has the same effect as the above embodiment.

Furthermore, various methods can be considered for forming the laminated film. For example, sputtering, CVD (chemical vapor deposition), plasma C! V.D.

Examples include photo-CVD, electron beam evaporation, Mo-CVD, etc., and there are no restrictions on the apparatus or method.

Furthermore, in the above embodiment, the welding glass (3) was also used for welding after the gap butting, but as shown in FIG. 10, glass! (11) is processed and the first one is made of low melting point glass (12).
MW may be used as shown in FIG.

〔Effect of the invention〕

As explained above, this invention involves forming grooves for glass on a substrate, molding glass into the grooves, removing excess glass, forming a metal magnetic film thereon, and stacking a plurality of these substrates. It involves unproductive processes such as high-temperature welding with glass molded into the groove, cutting and polishing it to a predetermined size to obtain pieces, and attaching each auxiliary core to the main core one by one. Since the number of steps is small, mass production is extremely high. Furthermore, since the metal magnetic film can be laminated with an insulator, eddy current loss can be suppressed.
This has the effect that a magnetic head with sufficient performance can be obtained even when the recording frequency is several tens of M)tm.

[Brief explanation of the drawing]

Figures 1 to 9 are diagrams showing an embodiment of the present invention, in which the manufacturing steps are sequentially arranged. Figure 3 shows glass molded on both sides of a ferromagnetic material, Figure 4 shows a laminated film laminated on one side of a ferromagnetic material,
Figure 5 is a diagram of several ferromagnetic substrates with laminated films stacked and bonded together, Figure 6 is a diagram of the one in Figure 5 cut to specified dimensions, and Figure 7 is the one in Figure 6. In parallel with this figure, the one in Figure 6 was further processed, Figure 8 is a diagram in which the one in Figure 6 and the one in Figure 7 were butted and joined together, and Figure 9 was cut out and processed from the one in Figure 8. FIG. Figures 10 and 11 show only the main parts of another embodiment of the present invention, Figure 10 is a diagram with additional grooves cut into the same as Figure 7, and Figure 11 is a diagram where they are butted together. It is. 12 to 14 are perspective views schematically showing a conventional magnetic head and its manufacturing method. FIG. 12 is a perspective view of the magnetic head, and FIG. 13 is a structure of an auxiliary core and a main core joined to it. FIG. 14 is a diagram in which another auxiliary core is to be joined by sandwiching the main core. In the figure, (1) is a ferromagnetic oxide substrate, (2) is a glass groove, (3) is a fused glass, (4) is a metal magnetic film, and (5) is a ferromagnetic oxide substrate.
) is an insulating film, (23) is a laminated film of a metal magnetic film and an insulating film, (6) is a piece, (7) is a gap surface, (8)
is the winding groove, (9) is the gap material, (10) is the gap,
(11) is a glass groove, (12) is a low melting point glass, (61
) is the pseudo gap length, (62). (63) is an auxiliary core, (64) is a main core, and (66). (68) is the glass, (67) is the winding groove, and (69) is the track width. Reference numerals in the middle of each drawing indicate the same or corresponding parts. Agent: Masuo Oiwa, Patent Attorney Figure 6, Figure 8: Diagram 8, Figure 1O@

Claims (10)

[Claims] (1) A process of processing a groove for embedding glass on the substrate, a process of molding glass into the groove and removing excess glass, and forming a metal magnetic film thereon using physical or chemical vapor deposition. a step of stacking a plurality of these substrates with the grooves facing each other and aligned, and welding the substrates together with the glass; and a step of stacking the stacked substrates along the direction of the grooves and perpendicular to the substrates. 1. A method of manufacturing a magnetic head, comprising a step of manufacturing a core half and/or a piece, which comprises at least a step of cutting along a flat plane. (2) The method of manufacturing a magnetic head according to claim 1, wherein the plane along the direction of the groove passes through the groove. (3) The method of manufacturing a magnetic head according to claim 1 or 2, wherein the substrate is elongated at right angles to the direction of the groove, and the core half is obtained by the cutting. (4) A patent in which the substrate is elongated at right angles to the direction of the groove, and the metal magnetic film is formed on both the upper and lower surfaces of the substrate, three or more substrates are stacked, and the cutting is performed to obtain connected pieces of core halves. A method for manufacturing a magnetic head according to claim 1 or 2. (5) Process winding grooves on one piece, polish the gap surfaces of both pieces, form gap material to a specified thickness on one or both gap surfaces, and butt the two pieces on the gap surfaces. 5. The method of manufacturing a magnetic head according to claim 4, wherein the magnetic head is welded at a high temperature and then cut into predetermined dimensions. (6) A method of manufacturing a magnetic head according to claim 1 or 2, wherein the substrate is large and is also cut into a plane perpendicular to the plane. (7) A method of manufacturing a magnetic head according to claim 6, wherein the metal magnetic film is formed on the substrate on both the upper and lower surfaces, three or more substrates are stacked, and the cutting is performed to obtain connected pieces of core halves. (8) Process winding grooves on one piece, polish the gap surfaces of both pieces, form gap material to a specified thickness on one or both gap surfaces, and butt the two pieces on the gap surfaces. 8. The method of manufacturing a magnetic head according to claim 7, wherein the magnetic head is welded at high temperature and cut into predetermined dimensions. (9) The method for manufacturing a magnetic head according to any one of claims 1 to 8, wherein the substrate is a ferromagnetic oxide. (10) The method for manufacturing a magnetic head according to any one of claims 1 to 9, wherein the metal magnetic film is a laminate in which a metal magnetic material and an insulator are alternately stacked.