JPS61192007A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To obtain a magnetic head which has high permeability and high magnetic characteristics in a high frequency band together with highly saturated magnetic flux density and can be mass-produced, by producing a composite magnetic block containing an alloy magnetic material piece having highly saturated magnetic flux density and an oxide magnetic material piece having high permeability in a high frequency band and then slicing said block matter. CONSTITUTION:An alloy magnetic material piece 1 has the highly saturated magnetic flux density and an oxide magnetic material piece 2 has the high permeability at a high frequency band. The upper surface 1a of the piece 1 is polished up to a mirror surface and used as a gap counter face. Then a nonmagnetic thin film 7 is formed and used as a gap material. The gap counter faces of a composite magnetic material piece 4 of such a constitution are butted with each other. Under such conditions, a pierced hole 8 for winding is formed together with plural track holes 9. A glass rod is put into the hole 8 and heated at a high temperature and then cooled when a fused glass matter 12 is filled. Thus both pieces 4 are unified into a composite magnetic block matter 10. Then this matter 10 is sliced into magnetic heads.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a magnetic head suitable for recording and reproducing signals including high frequency components such as video signals on a recording medium such as a metal tape having high coercive force. The present invention relates to a manufacturing method.

[Prior art]

Single-crystal ferrite, which has excellent wear resistance and magnetic permeability in high frequency bands, is usually used in magnetic helad cores used in video tape recorders (hereinafter referred to as VTRs) and the like.

Incidentally, in recent years, as the miniaturization of VTRs has been promoted, recording densities have been increasing, and metal tapes, which have a higher coercive force, are more suitable for such high-density recording than conventional iron oxide tapes. However, when trying to magnetize a metal tape suitable for high-density recording with a magnetic core made of the above-mentioned single-crystal ferrite, the metal tape is insufficient due to the low saturation magnetic flux density, which is considered the biggest weakness of single-crystal ferrite. The problem is that it cannot be magnetized.

Therefore, alloy magnetic materials such as sendust amorphous metal, which has a high saturation magnetic flux density, have recently attracted attention as materials for magnetic heads. However, this type of alloy magnetic material has problems such as a decrease in magnetic permeability in a high frequency band and wear resistance due to its low specific resistance value. For this reason, countermeasures have been taken such as attaching a reinforcing core to the side surface of the magnetic rad core and gluing it, but this method does not sufficiently prevent the decrease in magnetic permeability in the high frequency band, and it is not possible to adhere a reinforcing core separately. This brought about a new problem that hindered mass production of alloy heads.

[Object of the Invention] The present invention has been made in consideration of the above-mentioned conventional problems, and is characterized by the high saturation magnetic flux density of an alloy magnetic material, the high magnetic permeability in a high frequency band of an oxide magnetic material, and The object of the present invention is to provide a method for manufacturing a magnetic head that has the following magnetic properties and can be mass-produced.

[Structure of the invention]

The method for manufacturing a magnetic throat according to the present invention includes laminating an alloy magnetic material piece having a high saturation magnetic flux density and an oxide magnetic material piece having high magnetic permeability in a high frequency band, and stacking the alloy magnetic material piece in a longitudinal direction. Two composite magnetic material pieces are formed by forming a long groove for winding in the direction and a plurality of track grooves between the ends along the long groove for winding, and then forming a thin film of non-magnetic material on the surface facing the gap. The gap facing surfaces are joined to each other via the non-magnetic material thin film, and each track groove is filled with glass melt or the like to fix the composite magnetic material pieces to each other to form one composite magnetic block body. By slicing across the composite magnetic block,
The present invention is characterized in that it is constructed to obtain a high-performance magnetic head that has both the magnetic properties of an alloy magnetic material and an oxide magnetic material.

[□Example]

An embodiment of the present invention will be described below based on FIGS. 1 and 2.

A rectangular alloy magnetic material piece 1 and an oxide magnetic material piece 2 having the same shape are provided, and a glass film 3 is provided on the vertical surface of the mating surface of the oxide magnetic material piece 2.
Figure (a)]. - This glass film 3 is formed on the mating surfaces of the oxide magnetic material piece 2 by a method such as sputtering or vapor deposition. Next, with the glass film 3 sandwiched between the mating surfaces of the alloy magnetic material piece 1 and the oxide magnetic material piece 2, they are pressed together and heat welded to form a composite magnetic material piece 4 having a laminated structure. Figure (b)]
. The alloy magnetic material piece 1 is made of a material having a high saturation magnetic flux density, and the oxide magnetic material piece 2 is made of a material having a high magnetic permeability in a high frequency band.

Next, a winding long groove 5 is formed to a predetermined depth in the longitudinal direction of the upper surface of the alloy magnetic material piece 1 forming the upper layer of the composite magnetic material piece 4, and the winding long groove 5 and the composite along the winding long groove 5 are formed. A plurality of track grooves 6 are formed in communication with the end surface of the magnetic material piece 4 in a direction perpendicular to the winding long groove 5 [FIG. 4(C)]. The track grooves 6 are set at predetermined intervals from each other, and have a semicircular cross section in this embodiment.

- After forming the winding long groove 5 and a plurality of track grooves 6 on the top of the alloy magnetic material and the space 1, the upper surface 1a of the alloy magnetic material piece 1, which will be the surface facing the gap, is mirror-polished. Figure (d)]. Thereafter, a thin film 7 of a non-magnetic material such as Sin or a film serving as a gap material is formed on the polished surface by sputtering or the like [FIG. 4(e)].

Next, two composite magnetic material pieces 4 having the structure shown in FIG. They are butted and joined with the material thin film 7 interposed therebetween. In this state, the winding long grooves 5 and the track grooves 6 formed in the composite magnetic material piece 4 are arranged opposite to each other,
One winding through hole 8 and a plurality of track holes 9...
is formed. Thereafter, a glass rod is inserted into the winding through hole 8 and heated to a high temperature. When this glass rod is heated until it reaches a melting temperature, the glass rod becomes molten, so that the glass melt 12 is transferred to track holes 9 formed with track grooves 6 facing each other.
Pour into the inside of ... and fill it. When the track holes 9 are filled with the glass melt 12 and cooled, the composite magnetic material pieces 4 are integrated by welding the glass rods to form one composite magnetic block I.
O is formed [Figure (f)].

In addition, if the above-mentioned composite magnetic block body 10 is insufficient in strength or there is a risk of this, a through hole is provided along the joint surface of both composite magnetic material pieces 4, 4 as necessary,
A silver solder rod 11 may be inserted into this through hole, and when the glass rod is used for welding, the silver solder rod 11 may be heated and melted to perform silver welding at the same time [FIG. 4(g)].

Next, from the state shown in FIG. 1(f) or FIG. 1(g), the composite magnetic block 10 is sliced by machining to form seven dots 13 in the composite [FIG. 1(h)].

In this case, each track hole 9 filled with the glass solidified material 12a is arranged in parallel at a predetermined interval in the longitudinal direction of the composite magnetic block 10.
The composite magnetic block IO is sliced so that it is traversed through the center line of the composite magnetic block IO. The composite head chip 12 thus formed is, as shown in FIG. By welding with the silver solder rod 11, they are firmly integrated and a single magnetic head is obtained.

The magnetic head manufactured by the above method has a winding through hole 8 of the composite head chip 13, as shown in FIG.
A winding 14 is applied to the outer periphery of the composite head chip 13, and this is fixed on a magnetic head base 15. The magnetic head, which is set close to the magnetic tape (metal tape) 16, reads and reproduces information stored on the magnetic tape 16 that runs relative to the magnetic tape.

〔Effect of the invention〕

As described above, the present invention comprises laminating an alloy magnetic material piece having a high saturation magnetic flux density and an oxide magnetic material piece having high magnetic permeability in a high frequency band, and forming a winding layer in the longitudinal direction of the alloy magnetic material piece. After forming a plurality of track grooves between a long groove and an end surface along the long groove for winding, a thin film of non-magnetic material is formed on the surface facing the gap, and then the thin film of non-magnetic material is formed into two composite magnetic material pieces. The gap-opposing surfaces are joined to each other through the gap, and each of the track grooves is filled with a melt and fixed to form one composite magnetic block body, and then this composite magnetic block body is sliced across to manufacture a magnetic head. This is the way to do it. Therefore, in the magnetic head manufactured in this way, an alloy magnetic material with a high saturation magnetic flux density is used near the gap where magnetic saturation is likely to occur, so the metal tape, which is suitable for high-density recording, can be sufficiently magnetized. becomes possible. Furthermore, in order to compensate for the decrease in magnetic permeability of this alloy magnetic material in the high frequency band, an oxide magnetic material having high magnetic permeability in the high frequency band is used in the same core in areas other than the vicinity of the gap. This oxide magnetic material can sufficiently compensate for the drawbacks of alloy magnetic materials. Therefore, there is an advantage that a high-performance magnetic head having both the magnetic properties of the alloy magnetic material and the magnetic properties of the oxide magnetic material can be manufactured. Moreover, according to the method of the present invention, the problem of low wear resistance caused by the use of alloy magnetic materials is also simultaneously eliminated by the use of the oxide magnetic materials.
This eliminates the need for a separate work of adhering a reinforcing core as in the past, and as a result, it also has the secondary effect of promoting mass production of magnetic heads.

[Brief explanation of drawings]

(a) to (h) in FIG. 1 are process explanatory diagrams of a method for manufacturing a magnetic head showing one embodiment of the present invention, and FIG. 2 shows an example of use of a magnetic head manufactured by the method of the present invention. It is an explanatory diagram. 1 is an alloy magnetic material piece, 2 is an oxide magnetic material piece,
3 is a glass film, 4 is a composite magnetic material piece, 5 is a long groove for winding, 6 is a track groove, 7 is a thin film of non-magnetic material, 8 is a through hole for winding, 9 is a track hole, 10 is a composite magnetic block body ,1
1 is a silver solder rod, 12 is a glass melt, and 13 is a composite head chip.

Claims (1)

[Claims] 1. An alloy magnetic material piece having a high saturation magnetic flux density and an oxide magnetic material piece having high magnetic permeability in a high frequency band are laminated, and the alloy magnetic material piece is used for winding in the longitudinal direction. After forming a plurality of track grooves between a long groove and an end surface along the long groove for winding, a thin film of non-magnetic material is formed on the surface facing the gap, and then the thin film of non-magnetic material is formed into two composite magnetic material pieces. The gap-opposing surfaces are joined to each other through the gap, and each of the track grooves is filled with a molten material and fixed to form one composite magnetic block body, and then this composite magnetic block body is traversed to obtain a single magnetic head. A method of manufacturing a magnetic head, characterized in that: 2. The winding long groove and each track groove formed in the alloy magnetic material piece of the composite magnetic material piece are such that the winding through hole and the track hole are formed in the state where the two composite magnetic material pieces are joined. 2. The method of manufacturing a magnetic head according to claim 1, wherein each track hole is filled with molten glass, and each track hole is sliced across the center line of the track hole.