JPH04139605A - Manufacture of magnetic head core - Google Patents

Abstract

PURPOSE:To obtain a magnetic head core with high isotropic initial permeability by arranging a magnetic material block on the tape sliding surface of a gapped bar so as to be in contact with a metallic magnetic body at the time of gap jointing in a magnetic field. CONSTITUTION:After the magnetic material block 21 is arranged on the tape sliding surface 22 of the gapped bar 15 so as to be in contact with an amolphous alloy film 5 or 9, and in addition, the magnetic field is impressed to both the inside directions of the amolphous alloy film 5 or 9, the gapped bar 15 is cut at prescribed core width, and the tape sliding surface 22 is lapped down to a prescribed gap depth, and the magnetic head core is obtained. Since the magnetic material block 21 is arranged so as to be in contact with the amolphous alloy film 5 or 9 in this way, even if heat reatment is performed in a rotating magnetic field at the time of the gap joining, anisotropy is never caused in the magnetic core, and a good head characteristic can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a core of a magnetic head suitable for high-density magnetic recording systems such as high-quality VTRs and digital VTRs.

Conventional technology In recent years, the development of high-density magnetic recording systems such as high-quality VTRs and digital VTRs has become active, and in order to record such large amounts of information, magnetic recording media have changed from iron oxide to alloy powder. There is a shift towards high coercive force media such as media and metal evaporated media.

Therefore, it is desired to develop a magnetic head that has a high saturation magnetic flux density and excellent frequency characteristics that can be used with these high coercive force media.

Therefore, a magnetic head is currently being developed in which a magnetic metal material made of sendust, amorphous alloy, or the like having a high saturation magnetic flux density is disposed near the magnetic gap.

Hereinafter, a method for manufacturing a ring-shaped magnetic head core in which an amorphous alloy is used as the metal magnetic material and the main magnetic circuit is constituted by an amorphous alloy thin film will be described with reference to the drawings.

First, FIGS. 3(a) to 3(e) schematically show the manufacturing process of the magnetic head core. Sputtering a gold y:m material 5 made of a first amorphous alloy film or the like to serve as a magnetic core on one side of the substrate 3 and a second non-magnetic substrate 4, and a second adhesive glass film 6 on the opposite side. A third substrate 10 is created by sputtering a second substrate 7 formed by the method described above and a metal magnetic material 9 made of a second amorphous alloy film or the like which will become a magnetic core on one side of the third non-magnetic substrate 8 (a). ). Next, a stack of a large number of second substrates 7 is sandwiched between the first substrate 3 and the third substrate 10, and a pressure and heat treatment is performed to form a laminated block 11). Next, a pair of magnetic core halves 12a and 12b are cut out from the laminated block 11, and one magnetic core half 12a is cut out.
A winding groove 13 is provided in (C), and the magnetic gap surface 14 is polished smooth to form a magnetic gap material. Thereafter, the pair of magnetic core halves 12a and 12b are brought into contact with their magnetic gap surfaces 14, and subjected to pressure and heat treatment to form a gap doper 15 (evenly. This gap doper 15 is cut at an appropriate core width 16, and a tape The sliding surface 17 is wrapped to a predetermined gap depth to complete the magnetic throat core 18 (e
).

All heat treatment steps in this manufacturing method are performed at a temperature below the crystallization temperature of the amorphous alloy.

However, in the case of the amorphous alloy films 5 and 9 used in the head core described later, when the saturation magnetic flux density increases, the relationship between the crystallization temperature Tχ and the Curie temperature Tc becomes Tx<
It becomes Tc. Therefore, in order to perform heat treatment at a temperature below Tx and to disperse anisotropy and obtain a high isotropic initial i3 magnetic field, a rotating magnetic field is applied in the in-plane direction of the amorphous alloy films 5 and 9 during heat treatment. There is a need to.

Further, even in the case of an amorphous alloy where Tx>Tc, heat treatment in a rotating magnetic field is effective in order to further disperse the anisotropy.

Problems to be Solved by the Invention However, in the above-mentioned conventional manufacturing method, even if heat treatment is performed in a rotating magnetic field, the demagnetizing field coefficient differs in each region within the head core due to the influence of the shape of the head core. There was a problem that a magnetic field of - type was not applied isotropically, resulting in anisotropy in the head core.

Figures 4(a) to (C) show the change in magnetization in the gap depth region when a rotating magnetic field is applied, and the film thickness is 4.
When a rotating magnetic field Hext of 5000 e is applied to the head core 19 (a) consisting of the amorphous alloy films 5 and 9 of 0 μm, the magnitude and direction of magnetization in the gap depth region 20 near the winding groove 13 in (b) are 1. seek by truth,
The vector representation is (C). As shown in Figure 4 [1], the 1 summer method is to keep the magnitude of the applied magnetic field Hext constant at 5000e, and change the magnetic field application angle θ from Oo to 360°. Head core 19 by changing every 10 degrees
The magnetization of the gap depth region 20 at each magnetic field application angle θ was determined by the magnetic moment method.

As can be seen from FIG. 4(C), even though a uniform magnetic field is applied isotropically, the direction of magnetization tends to be directed toward the X direction where the demagnetizing field coefficient is small. In particular, in the gap depth region 20, the demagnetizing field coefficient in the Y direction is large due to its shape, so that the applied magnetic field is not applied isotropically and the direction along the slope of the first winding groove 13 becomes the easy axis. The problem was that it became anisotropic and the initial magnetic permeability in the direction along the magnetic path decreased. Furthermore, although the influence of the demagnetizing field can be reduced by making the applied magnetic field extremely large, this is hardly a practical method when actually manufacturing a magnetic head'.

The present invention solves the above-mentioned conventional problems, and by eliminating the non-uniformity of the applied magnetic field in each region within the bend core 19 due to the shape of the head core 19, the decrease in the initial magnetic permeability in the magnetic path direction is suppressed. It is an object of the present invention to provide a method for manufacturing a magnetic core having high isotropic initial magnetic permeability without any magnetic flux.

Means for Solving the Problems In order to achieve the above object, the present invention forms a winding groove in at least one of a pair of magnetic core halves in which the vicinity of the magnetic gap surface is made of a metal magnetic material, and When joining the bodies at the magnetic gap plane, a magnetic block is placed on the tape sliding surface of the pair of magnetic core halves so as to be in contact with the metal magnetic body, and then the pair of magnetic core halves are bonded while being heat-treated in a magnetic field. It is characterized by joining the magnetic core halves.

Effect Therefore, according to the present invention, when forming a gap, a magnetic block is arranged on the tape sliding surface of the gap doper so as to be in contact with the metal magnetic material that becomes the magnetic core, and the magnetic block is inserted from the tip of the winding groove. By increasing the distance to the end, the demagnetizing field coefficient in the Y direction in the gap fat H region is reduced, a -like rotating magnetic field is applied to the entire head core, and the anisotropy is dispersed, resulting in isotropic A high initial permeability can be obtained.

EXAMPLE Below, a method for manufacturing a magnetic head according to an example of the present invention is shown in FIGS. 1 to 3 (a), (b), (C),
As with (e), the same numbers are used for the same parts as in the conventional example, detailed explanations of the same steps as in the conventional example are omitted, and differences will be explained. FIG. 1 is a perspective view in one step of the method for manufacturing a magnetic head according to the present invention, and FIG.
This process corresponds to the step of creating the gap doper 15 by abutting the magnetic gap surfaces 14 and applying pressure and heat treatment. As shown in FIG.
A magnetic field of 1 kOe is applied in the in-plane direction of the amorphous alloy film 5 or 9 while rotating at a rotation speed of 12 Orpm. The thickness of the magnetic block 21 in this example is 2II11. Thereafter, this gapped bar 15 is cut to have a predetermined core width 16, and the tape sliding surface 22 is ramped to a predetermined gap depth to complete a magnetic head core 18 as shown in FIG. 3(e).

Figure 2 shows a 1k sample of an amorphous alloy film with a thickness of 30 μm cut into squares and a hole of 0.4φ in the center.
These are the results of measuring the initial magnetic permeability μi at 1 MHz in a ring shape when heat treated in a rotating magnetic field of Oe. The heat treatment was performed at 480° C. for 30 ml, and the experiment was conducted with four different distances d from the edge of the hole at the center of the sample to one side of the square.

As a result, it can be seen that a high initial magnetic permeability is obtained isotropically when d≧1 and 3, but as d becomes smaller, the initial magnetic permeability μI tends to decrease. This is because as d becomes smaller, the demagnetizing field coefficient in the direction perpendicular to the circumference of the hole increases, and even though a −-like rotating magnetic field is applied, a magnetic field is not effectively applied in the circumferential direction of the hole. This is thought to be due to the anisotropy in which the circumferential direction is the axis of easy magnetization.

As described above, according to the above embodiment, since the magnetic block 21 is arranged on the tape sliding surface 22 of the gap doper 15 so as to be in contact with the amorphous alloy film 5 or 9,
Even though heat treatment is performed in a rotating magnetic field during gap bonding, good head characteristics can be obtained without anisotropy occurring in the magnetic core.

Further, in this example, a CoNbZr amorphous alloy with Tx<Tc was used as the metal magnetic material, but a composition-modified nitride amorphous alloy film may also be used, and a heat treatment process in a magnetic field is required. It is also effective in manufacturing magnetic head cores made of magnetic films. Further, in order to improve broadband characteristics, a similar effect can be obtained in the manufacture of a magnetic head core using a laminated film in which metal magnetic films and insulating films such as SiO2 are alternately stacked as the magnetic core. Furthermore, in this embodiment, the magnetic block 21
Sendust was used as the material, but the same effect can be obtained by using other materials such as ferrite blocks or soft iron.

In addition, as a method to obtain the same effect, it is possible to increase the distance 1lld from the tip of the winding groove 13 of the pair of magnetic core halves 12a, 12b to be gap-joined to the tape sliding surface in advance. It has been found that the manufacturing method according to the present invention is superior to other problems, such as poor performance and large track deviations after the head is wrapped to a predetermined gap depth.

Effects of the Invention As is clear from the above embodiments, the present invention provides a magnetic head core that requires heat treatment in a magnetic field, in which a magnetic block is brought into contact with a metal magnetic material on the tape sliding surface of a gap doper during gap bonding in a magnetic field. By arranging it like this, the demagnetizing field coefficient in the gap depth direction is reduced,
It is possible to apply a -like magnetic field to the entire head core, disperse anisotropy, and manufacture an excellent magnetic head core having isotropically high initial i3 magnetic coefficient.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of one step in a method for manufacturing a magnetic head core according to an embodiment of the present invention, FIG. 2 is a characteristic diagram illustrating the effects of this embodiment, and FIGS. 3(a) to (e) are conventional FIG. 4 (al.
to (C) are conceptual diagrams illustrating changes in magnetization in a gap depth region near a winding groove when a rotating magnetic field is applied in a conventional method for manufacturing a magnetic head. 5.9... Gold If material (amorphous alloy WI
), 12a, 12b...Magnetic core half, 13.
...Winding groove, 14...Magnetic gap surface,
21... Magnetic block, 22... Tape sliding surface.

Claims (2)

[Claims] (1) A winding groove is formed in at least one of a pair of magnetic core halves in which the vicinity of the magnetic gap surface is made of a metal magnetic material, and when the pair of magnetic core halves are joined at the magnetic gap surface, A magnetic head core characterized in that a magnetic material block is arranged on the tape sliding surface of the magnetic core halves so as to be in contact with a metal magnetic material, and then the pair of magnetic core halves are joined while being heat-treated in a magnetic field. manufacturing method. (2) The method for manufacturing a magnetic head core according to claim 1, wherein the heat treatment in a magnetic field is heat treatment in a rotating magnetic field.