JPS6032107A - Magnetic head - Google Patents

Abstract

PURPOSE:To increase the reliability and to reduce the cost for a magnetic head containing a ferromagnetic thin metallic film formed on a junction surface of paired magnetic core halves, by tilting both the magnetic gap forming surface and the thin metallic film forming surface at desired angles. CONSTITUTION:Grooves 21a1-21a3- are formed with V-shaped sections on a ferrite substrate 21. Then oxide glass 22 of a high melting point is filled into those grooves and polished to obtain a plane. While grooves 21b1-21b3- are formed with V-shaped sections at the areas where no glass 22 is filled. Thin metallic films 23 are laminated via insulated films of high hardness and polished into a plane to obtain core half blocks 31a and 31b. The block 31a contains a winding groove 25 and a glass groove 26 and is butted to the other block 31b. Then a glass rod is put into the groove 26 and fused, and the fused glass is filled into the hollow parts on the surface of the film 23. Then both blocks are put together. This combined block is sliced to cut the groove 26 and then polished. Thus it is possible to obtain a magnetic head having high reliability and containing a magnetic gap (g) tilted in the lamination direction of the film 23.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic head, particularly a magnetic head for use in a VTR or the like.

BACKGROUND TECHNOLOGY AND PROBLEMS In recent years, with the development of magnetic recording technology, magnetic heads for VTRs have become capable of recording and reproducing magnetic tapes with high magnetic flux density and high coercive force. In order to improve the recording density, it is required to make the track as narrow as possible. To meet the former requirement, metal magnetic materials (amorphous, sendust, permalloy, etc.) with high saturation magnetic flux density are used in place of ferrite. In addition, to meet the latter requirement, sputtering, vapor deposition,
A metal magnetic thin film formed by a vacuum thin film formation technique such as ion silating is suitable.

Various types of magnetic heads have been proposed in which this ferromagnetic metal thin film is formed. For example, the magnetic head (1) shown in FIG. 1 has a magnetic core (LA) with a metal magnetic thin film (3) such as Shisen dust formed by sputtering on a non-magnetic substrate (2).
, (lb) are butted against each other, and the magnetic head (1') shown in FIG. 2 is a ferrite plate (4a).

(4b) was formed as shown in Figure 1.
Furthermore, the magnetic head (1'') shown in FIG.
It is formed by su/arm ivy.

However, with the configuration shown in Figures 1 and 2, that is, the metal magnetic thin film (3) created by a center thin film forming technique such as sputtering on a non-magnetic substrate (2), the film growth rate is extremely slow and it takes a long time to create. There are drawbacks that require

In addition, in the case shown in Fig. 3, the gold 5IA44 thin film (3) is in the direction perpendicular to the magnetic path, so there is a lot of eddy current loss, and when the gold 5IA44 thin film (3) is further laminated, the insulating film between the films is It has the disadvantage of acting as a gap.

Purpose of the Invention In view of the above, the present invention forms the gap and the vicinity of the winding hole with a metal magnetic thin film, and forms most of the tape sliding contact surface with a highly wear-resistant ferromagnetic oxide, thereby improving reliability. An object of the present invention is to provide an expensive and inexpensive magnetic head.

Summary of the Invention In order to achieve the above-mentioned object, the present invention forms a ferromagnetic metal thin film on the joint surface of a semi-vacuum pair of magnetic cores made of ferromagnetic oxide using vacuum thin film forming technology, and then abuts the semi-vacuum core pair to form a magnetic gap. In the magnetic head that forms the
The magnetic magnet forming surface and the ferromagnetic metal thin film forming surface are formed to be inclined at a predetermined angle.

Example Hereinafter, the present invention will be described in detail with reference to FIG. 4 and subsequent figures.

First, FIGS. 4 and 5 show an example of a magnetic head α→ according to the present invention. The magnetic gap g whose width is defined by filling with a non-magnetic or magnetic material (b) such as glass at the joining surface of the magnetic core semi-dead pairs (lla) and (llb) made of ferromagnetic oxide such as ferrite is metal. Magnetic? )! J membrane (1
The force is applied at approximately 45° to the stacking direction of 1, and the metal magnetic thin film (
11C (13t), (13i), . . . ] and the magnetic gap g is oriented in such a direction that the interaction between the laminated insulation II (+')) and the magnetic gap g during recording and reproduction on the tape is minimized.

That is, in the magnetic head according to the present invention, as shown in FIG. 6, where both magnetic core half holes (l1m) and (llb) are separated from the gap surface g, most of the shortest distance region of the magnetic path is made of the metal magnetic thin film Q1. This is an effective arrangement even if the area of the metal magnetic thin film α is small, and the metal magnetic thin film α
→ has a hard-wearing structure and most of the tape-contacting surface is made of ferrite forming half-holes (l1m) and (llb) of both magnetic cores, so that a highly wear-resistant magnetic head is constructed. Note that in FIGS. 4 and 6, (1) indicates a winding groove.Next, the manufacturing process of an example of the magnetic head according to the present invention will be explained with reference to FIGS. 7 to 14.

First, as shown in FIG. 7, a groove is formed on the ferrite substrate eυ by a rotary grindstone or electrolytic etching, for example, a cross section V
Letter-shaped grooves (21a) ((21ax), (21a*), (
21as) . Next, as shown in Figure 9, the groove (21
3θ.

(21az), (21as)... grooves are formed between the gaps, that is, the portions that are not filled with glass 4, and, for example, grooves with a V-shaped cross section similar to those described above (21bX (21bs), (21b
) + (21bs)...], and this groove (21bs)...] is formed.
b) Metal magnetic thin films (c) C(231), (2
3*)...'Jki5102+ Zr02t Ta20
They are laminated with a high hardness insulating film (24) such as No. 5 (see FIG. 10) interposed therebetween.

Thereafter, as shown in FIG. 11, the surface polishing process is performed again to form half-core blocks (31m) and (31b). And one core half-vacant block (31a) has a 12th
As shown in the figure, groove the winding groove (a) and glass groove (a). Next, one of the grooved core half-closed blocks (21a) and the other core half-closed block (31b) without grooves are butted against each other with their plane parts J) to form the winding grooves (2).
51 and the glass groove (A), and melt this glass rod to form the surface (lulu) of the metal magnetic thin film portion (23).
l groove (21b') ((21b't) (21b' goose)
(21b's)...] is filled with molten glass C7) into the hollow part formed by J cedar, and both blocks (31a), (
31b) are fused together (see Figure 13).

This combined block is shown on the A-A' line shown in Figure 13.
After cutting out the rear glass groove (c) to form a head material, both surfaces 1011 and the tape sliding surface on the front surface are polished to form a magnetic gap g as shown in FIG. 14. Is it gold-plated tt? Special layer (2
Magnetic head that forms the required angle with the stacking direction of the floor.

(31) is obtained.

By forming a magnetic head in this manner, the number of magnetic healds that can be created from a unit area of metal magnetic thin film formation is much larger than that of the conventional method in which a metal magnetic thin film layer is formed on a flat surface, that is, the head width is 3 m.

If the head chip thickness is 150 to 200 μm and the cutting margin for slicing is 100 to 150 μm, it is possible to create a magnetic head about 10 times larger.

In addition, since the ferrite block Cυ with grooves is directly used as the substrate for forming the modern magnetic thin film (c), there is no need to attach the ferrite from both sides as shown in Figure 2, which significantly reduces the number of agricultural man-hours. It has been reduced to become a cheap form of entertainment.

FIG. 15 shows the combination of core blocks to create a magnetic head for azimuth recording, and each core half block (31a
) (31b) groove (21
The grooves (21b) forming the metal magnetic thin film layer (c) are formed with asymmetrical inclinations on both sides, that is, one side is formed at a steep angle and the other side is formed at a gentle angle. ),
(21b) is melted and filled with glass (24) and a metal magnetic thin film layer (c) is formed on both cores of the Glock (31).
m) and (31b) are bonded together so that the metallic thin film layer (c) is continuous with the metal on the gently inclined surface. And B
- 16th by slicing at the position of line B'
A magnetic head (31') having an azimuth magnetic gap g' as shown in the figure can be obtained.Although it is not limited to this example, the depth of the winding groove (c) as shown in Figure 16 can be obtained. By forming the winding groove shallowly, that is, by processing the winding groove (c) so as to leave a part of the metal magnetic thin film layer (231). The metal magnetic film extends continuously from the front gap to the back gap.

FIG. 17 shows another embodiment of the present invention, in which metal magnetic thin film layers (2'3) are arranged on both side surfaces of both core halves (31a) and (31b).

Another embodiment shown in FIG. 18 is a metal magnetic thin film (2, 1
This is the case where the gap width is narrowed by forming only one layer.

Further, in still another embodiment shown in FIG. 19, a core block (31m) is arranged such that the tip of the ferrite forming the core half-hole (31&ru (31b)) is located behind the gap surface on the tape sliding surface. A leeway may be provided for the polishing dimensional accuracy (determination at the end of polishing) in (31b).

For this purpose, the metal magnetic thin film layer (c) in the third step described above is required.
In the grooving process of the forming groove (21b), the groove width and depth may be increased so that the groove edge portion sufficiently covers the glass portion (221). In the magnetic head, the angle formed between the laminated surface of the metal magnetic thin film layer (c) and the gap surface g must be 2O2 or more, and if the angle is less than that, crosstalk from adjacent tracks will increase, and most preferably. It is better to set the angle at 30° or more.The maximum angle can be up to 90°, but from the viewpoint of wear resistance, it is preferable to set it at 80° or less.In this example, the metal magnetic thin film layer (c) The insulating film (24) interposed between was 5102tTa205, but At20.
* Other highly wear-resistant insulating films such as ZrO2゜513N4 may also be used.Also, metal magnetic thin film layers (2 moat also S/4
The material is not limited to sendust produced by vine dust, but may be any metallic magnetic thin film with a high saturation magnetic flux density, such as an amorphous magnetic film produced by snow vine dust.

It goes without saying that the oxide magnetic material used as the substrate by filling and embedding glass (2) or other non-magnetic material may be Ni-Zn ferrite, ferroxgrainer or other high frequency oxide magnetic forest materials. .

As described above, in this example, the metal magnetic thin film layer C forming the magnetic gap g is formed by the vacuum thin film forming technique, that is, the -IIi-vacuum thin film forming apparatus by alternating with the insulating film (24). Compared to the case where metal elastic magnetic foil is laminated with an adhesive layer such as a glass inorganic adhesive or an organic adhesive, there are no gaps between the metal magnetic thin films, and the lamination of metal magnetic thin films is conventional. This process can be performed more easily and reliably than lamination by handling, and a highly wear-resistant magnetic head capable of recording and reproducing at high magnetic flux density with excellent high frequency characteristics can be obtained.

Effects of the Invention As described above, according to the present invention, the vicinity of the magnetic gap is formed of a metal magnetic thin film, and in the region 2q apart from the vicinity of the magnetic gap, most of the tape sliding surface is made of a highly wear-resistant ferromagnetic oxide film. Since it is made of a material, it has the advantage that a highly wear-resistant magnetic head capable of recording and reproducing at a high magnetic flux density with excellent high frequency characteristics can be provided at a low cost.

[Brief explanation of the drawing]

1 to 3 are perspective views of each side of a conventional magnetic head for a VTR, FIG. 4 is a perspective view of an example of the magnetic head according to the present invention, FIG. 5 is an enlarged front view of the same part, and FIG. 7 to 13 are assembly process diagrams of an example of the magnetic head according to the present invention. FIG. 14 is a perspective view of a magnetic head manufactured by the same process. FIG. 15 is a perspective view showing the cutting process of a magnetic head for azimuth recording, FIG. 16 is a perspective view of a magnetic head for decoy azimuth recording, and FIGS. 17 to 19 are perspective views of the other side of the magnetic head according to the present invention. be. In the figure, (lit, (31-), (31mm) magnetic head, (l1m), (llb). (31a), (31b) are magnetic core half-closed, 01.
(231 is a metal magnetic thin film layer, 02, (23 is a non-magnetic material, and g is a magnetic gap. Sony Magne P, 6-5-6 Kitashinagachi Ducts Co., Ltd.

Claims (1)

[Claims] In a magnetic head, a ferromagnetic metal thin film is formed on the joining surface of a semi-vacuum pair of magnetic cores made of ferromagnetic oxide by vacuum thin film formation technology, and a magnetic gap is formed by abutting the semi-vacuum pair of magnetic cores. A magnetic head characterized in that a gap forming surface and the ferromagnetic metal thin film forming surface are inclined at a predetermined angle.