JPH0660315A - Method of manufacturing magnetic head - Google Patents

Abstract

(57) [Summary] [Object] It is an object of the present invention to provide a magnetic head for efficiently recording and reproducing a high-frequency signal such as a high-quality VTR or a digital VTR. [Structure] A conductive film 3 is provided on at least one side of a magnetic head having a metal magnetic film 2 provided on a non-magnetic substrate 1, and an electric current is passed through the conductive film 3 to form a winding window 6 in the film surface of the metal magnetic film 2. Heat treatment is performed by generating a magnetic field radially in the center. [Effects] The magnetic easy axis has a radial easy axis around the winding window 6 in the film surface of the metal magnetic film 2, and most of the magnetic paths of the magnetic head can effectively utilize the characteristic in the hard axis direction, and it is high even at high frequencies. Recording and playback can be done efficiently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magnetic head suitable for efficiently recording / reproducing a high frequency signal such as a high definition VTR or a digital VTR.

[0002]

2. Description of the Related Art In recent years, a system for handling a wide band signal such as a high definition VTR or a digital VTR has been actively developed, and a magnetic recording medium has a high coercive force medium in order to record such a large amount of information. It is changing to. Therefore, as a magnetic head, it is desired to develop a magnetic head having a high saturation magnetic flux density and excellent frequency characteristics, which is compatible with these high coercive force media. Currently, a magnetic head using a metal magnetic material having a high saturation magnetic flux density is being developed, but its high frequency characteristics are restricted by the snook limit line due to ferromagnetic resonance.

[0003]

In a system for handling a wide band signal such as a high definition VTR or a digital VTR, a core material for a magnetic head is required to have a high initial permeability in a high frequency band. (FIG. 8) shows the frequency characteristics of the initial permeability of the laminated film of the Co-based amorphous magnetic film and the SiO ₂ film. In the amorphous laminated film, the thickness of the magnetic film per layer is 4 in consideration of the eddy current loss.
The thickness is 5 μm and the SiO ₂ film thickness between layers is 0.1 μm, and five layers are laminated. In the figure, (2) is a non-oriented amorphous laminated film, the eddy current loss is improved by the laminating effect, but the initial magnetic permeability in the frequency band of 30 MHz or more is 500 or less.

Therefore, if such a non-oriented magnetic film is used as a head core, it is difficult to realize a high-performance head compatible with the above high frequency system.

On the other hand, the initial permeability characteristics of a multilayer film in which amorphous magnetic films having uniaxial anisotropy are laminated with their easy magnetization axis directions aligned are measured in the easy magnetization axis direction as shown in (1). Shows very low initial magnetic permeability characteristics, whereas when measured in the hard axis direction, it maintains a high magnetic permeability up to high frequencies as shown in (3), and even at 60 MHz,
It has the above value. Therefore, if the magnetic path is formed only in the hard axis direction, a head having high reproduction efficiency up to high frequencies can be realized. In a ring-type head such as a video head, in order to form a magnetic path only in the direction of the hard axis, anisotropy is added so that the track width direction of the head becomes the axis of easy magnetization, or a winding window is provided. The axis of easy magnetization may be provided radially as the center.

However, it is very difficult at present to attach the easy axis of magnetization in the track width direction due to the influence of the demagnetizing field due to the shape of the head, and it is extremely difficult to radially attach the easy axis of magnetization in the manufacture of the head. The current situation.

[0007]

According to the method of manufacturing a magnetic head of the present invention, a non-magnetic substrate provided with a metal magnetic film and a conductive film is laminated to form a laminated body, and a pair of core halves is formed from the laminated body. To form a winding window on the magnetic gap surface of at least one of the core halves, but abut the pair of core halves at the magnetic gap surface, and apply currents to the conductive film in opposite directions with the magnetic gap surface as a boundary. It is a method of manufacturing a magnetic head, which is characterized in that heat treatment is performed while flowing.

[0008]

According to the structure of the present invention, since the easy axis of magnetization is provided radially in the film surface of the metal magnetic film with the winding window as the center, most of the magnetic path of the magnetic head is in the hard axis direction. Excellent characteristics can be effectively used, and recording and reproduction can be performed with high efficiency even at high frequencies.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (FIG. 1), (FIG. 2), (FIG. 3) and (FIG. 4) are perspective views showing a manufacturing process of a magnetic head in an embodiment of the present invention.

FIG. 5 is a diagram showing a magnetic field 11 generated from the conductive film 3 in which a current having a winding shape of the head core and having a winding window 6 is passed. The currents are made to flow in the opposite directions from the vicinity of the gap surface of the head end surface with the gap surface as a boundary, and a magnetic field is generated radially around the winding window 6.

FIG. 6 is a side view of the flow of the magnetic field 11 when the conductive film 3 is arranged on one side of the metal magnetic film 2. The magnetic field 11 generated by the current flows through the metal magnetic film 2 having a high magnetic permeability as shown in the figure. Therefore, the metal magnetic film 2
, A magnetic field is applied in the radial direction around the winding window 6 in the film plane. That is, when a magnetic head is manufactured by the method of the present invention, a magnetic field is radially applied around the winding window in the film surface of the metal magnetic film during heat treatment, so that the winding window 6 as shown in FIG. It is possible to manufacture a ring head having the easy axis 10 of magnetization in the radial direction. Most of the magnetic paths of this head can effectively utilize the characteristics in the direction of the hard axis, and signals can be recorded and reproduced with sufficiently high efficiency even at high frequencies.

First, a magnesium titanate-based non-magnetic substrate
1. Sputter metal magnetic film 2 and insulating film on one side of 1
Stack alternately. In this embodiment, the metal magnetic film is Co—N.
Using an amorphous alloy with a composition of b-Zr-Ta
, Saturation magnetic flux density Bs to 8000 G, Curie temperature Tc
~ 490 ° C. The film thickness per layer is the frequency used.
It is less than the thickness considering eddy current loss in several bands.
It The insulating film is SiO ₂ With a thickness of 0.1 μm
It was

Next, the conductive film 3 is formed on one surface of the other non-magnetic substrate 1 by vapor deposition. In this embodiment, the conductive film is C
The thickness was 50 μm using u.

Next, the substrate 1 on which the metal magnetic film 2 is formed
And the substrate 1 on which the conductive film 3 is formed are alternately formed on the metal magnetic film 2
Then, the substrate 1 and the conductive film 3 and the substrate 1 are overlapped so as to face each other, and the substrates are adhered to each other with a bonding glass 4 such as crystallized glass to form a laminated body 5 as shown in FIG.

Next, the laminated body 5 is cut to form a pair of core halves 5a and 5b. One core halves 5a of the magnetic gap surface coil window 6 is formed both core halves 5a, polished smooth the gap surface of 5b, the pair of through SiO ₂ and a gap material 7 such as a high-melting glass The core halves 5a, 5b are butted against each other at the gap surface and heat-treated to produce a gapped bar bonded at the gap surface.

Next, an electric current is applied to the conductive film 3 of the gap bar to anneal it. Next, the gap bar is cut to a predetermined thickness 8 to obtain a head chip as shown in (FIG. 4).

In the head manufactured by the above method, the magnetic easy axis 10 causes the winding window 6 to move as shown in FIG. 4 by applying the magnetic field as explained in the section of operation during the heat treatment. Radially formed in the center.

FIG. 7 is a magnetic head (b) using a conventional non-oriented laminated metal magnetic film, and a magnetic head having an easy axis of magnetization formed radially around a winding window by the manufacturing method of the present invention. The frequency characteristic of the relative output of (a) is shown. 30M
It can be seen that at high frequencies of Hz and above, the magnetic head of the present invention exhibits high-frequency characteristics far exceeding those of conventional magnetic heads.

[0019]

According to the manufacturing method of the present invention, 30 MHz
A high frequency magnetic head capable of recording and reproducing with sufficiently high efficiency even in the above high frequency band can be easily obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a manufacturing process of a magnetic head according to an embodiment of the present invention.

FIG. 2 is a perspective view of a laminated body in the manufacturing process of the magnetic head in the embodiment of the invention.

FIG. 3 is a perspective view of a core half body in the manufacturing process of the magnetic head according to the embodiment of the invention.

FIG. 4 is a perspective view of a head chip in the manufacturing process of the magnetic head in the embodiment of the invention.

FIG. 5 is a principle diagram showing the operation of the embodiment of the present invention.

6 is a sectional view of FIG.

7A is a graph showing a relative output frequency characteristic of a magnetic head of the present invention, and FIG. 7B is a graph showing a relative output frequency characteristic of a conventional magnetic head.

FIG. 8 is a graph showing frequency characteristics of initial magnetic permeability of a metal magnetic film depending on anisotropy direction (1) is a graph measured in the easy axis direction of magnetization (2) is a graph of non-oriented amorphous laminated film (3) Is the graph measured in the direction of the hard axis

[Explanation of symbols]

 1 Non-magnetic Substrate 2 Metal Magnetic Film 3 Conductive Film 4 Bonding Glass 5, 5a, 5b Core Half 6 Winding Window 7 Gap Material 8 Cutting Width 9 Magnetic Gap 10 Easy Axis 11 Magnetic Field

Claims (4)

[Claims] 1. A non-magnetic substrate provided with a metal magnetic film and a conductive film is laminated to form a laminated body, and a pair of core halves are cut out from the laminated body, and a magnetic gap surface of at least one of the core halves. A magnetic head, characterized in that a winding window is formed in the magnetic head, the pair of core halves are butted against each other at a magnetic gap surface, and the conductive film is heat-treated while flowing currents in opposite directions with the magnetic gap surface as a boundary. Method. 2. The method of manufacturing a magnetic head according to claim 1, wherein the conductive film is a metal magnetic film. 3. The magnetic material according to claim 1, wherein a laminated body is formed by laminating non-magnetic substrates in which two or more metal magnetic films are provided in layers with an insulating film interposed therebetween. Head manufacturing method. 4. The method of manufacturing a magnetic head according to claim 1, 2 or 3, wherein the metal magnetic film is an amorphous magnetic film.