JPS598120A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To produce a magnetic head having a high saturation magnetic flux density, by using magnetic materials having a high saturation magnetic flux density in a magnetic gap part. CONSTITUTION:After V-shaped grooves 2 are cut obliquely in both iron core pieces 1 and 1a, a film 3 of an sendust alloy having a high saturation magnetic flux density is formed on the side face, where V-shaped grooves 2 are formed, with about 20mu thickness by the vapor deposition method. A groove 4 for coil winding is cut in one iron core 1a, and an SiO2 film for forming a magnetic gap is formed on the sendust alloy layer of a magnetic pole part 5. Iron core pieces 1 and 1a are pressurized from both sides while allowing respective V- shaped grooves 2 to face each other, and in this state, both iron core pieces are heated and silver-soldered. An iron core block formed by silver soldering is cut along alternate long and short dash lines to form iron cores for magnetic head. Thus, the magnetic head which can record sounds and pictures with enhanced signal strength is produced.

Description

[Detailed description of the invention] The present invention relates to a method of manufacturing a magnetic head.

Recently, in order to increase the recording density on magnetic tape in video, audio, and audio magnetic recording devices, the size of magnetic particles coated on the magnetic tape has become smaller and smaller, and the thickness of the magnetic particle coating layer and the tape base have become smaller and smaller. The thickness of the material itself also tends to become thinner.

Therefore, magnetic fine particle materials with a large coercive force Hc are now required, and currently home VTRs are
CrO2 tape or Co-γ-F6203 tape with c=700-1-ruste nod is used. Also,
Currently, Hc is already in practical use in audio.
>1200 Erste Nod metal tape is being considered for use in videos. Generally, as the coercive force Hc increases, the residual magnetic flux density Br also increases, and in the case of metal tapes, Br reaches as high as 3000 to 4000 couns, which is twice as high as that of conventional tapes. Therefore, it is expected that the recording signal strength and the accompanying reproduction sensitivity will increase. However, in order to record with high magnetic flux density,
Recording magnetic heads are also required to use materials with a high saturation magnetic flux density. In contrast, magnetic heads using alloys such as sendust or amorphous magnetic materials, which have a saturation magnetic flux density (more than 10,000 Gauss) approximately three times that of ferrite, which has traditionally been used in magnetic heads, are being developed. However, these materials have higher electrical conductivity than ferrite, and as the frequency increases, the effective magnetic permeability decreases due to eddy current effects, and their brittleness makes it difficult to manufacture magnetic heads for narrow tracks. It has the disadvantage of being

The purpose of the present invention is to combine the high saturation magnetic flux density characteristics of Sendust alloy and amorphous magnetic materials with the low electrical conductivity of ferrite magnetic materials conventionally used in magnetic head cores, and to achieve the performance of recent magnetic tapes. It is an object of the present invention to provide a method for manufacturing a magnetic head having a high saturation magnetic flux density that is commensurate with the improvement and whose characteristics do not deteriorate even in a high frequency region.

For the above purpose, the method for manufacturing a magnetic head according to the present invention includes a first ferromagnetic material having a magnetic circuit divided into two at a location other than the magnetic gap of the magnetic head with which the magnetic head makes sliding contact. Two core pieces are prepared, and the two magnetic pole faces of these two core pieces, which are opposite to each other across a magnetic gap, are saturated by the first ferromagnetic material. forming a magnetic layer made of a second ferromagnetic material having a high magnetic flux density; and further forming a magnetic layer made of the second ferromagnetic material on a magnetic pole portion of at least one of the two core pieces. The process consists of forming a non-ferromagnetic material layer on top of the magnetic gap, and then forming a magnetic circuit by joining the magnetic circuit cross sections of the two iron core pieces. There is.

Embodiments of the present invention will be described below based on the drawings.

First of all, the main part of the magnetic path of the magnetic head is shown in FIG.
Two iron core pieces 1 and 1a as shown in A) are cut out of ferrite material, and in order to form the magnetic head pole part narrow in width corresponding to the track width of the magnetic tape, as shown in Fig. 1(B). After diagonally cutting V-shaped grooves 2 into both core pieces 1 and 1a, a film 3 of Sendust alloy having a high saturation magnetic flux density is deposited or sputtered on the side where the ■-shaped grooves 2 are cut. Figure 1 (C)).

The film thickness is approximately 20 mm in consideration of the electrical conductivity of Sendust alloy.
By setting μ, the influence of overcurrent on effective magnetic permeability is ignored up to a frequency of 5 MHz.

Furthermore, a groove 4 for winding the excitation coil is cut into one of the iron cores 1a as shown in FIG. A film of 5i02, which is a nonmagnetic material, is formed by vapor deposition or sputtering.

(SiO2 film is not shown.) Next, the iron core piece 1 shown in FIG. 1(C) and the iron core piece 1 processed to the stage shown in FIG. 1(D)
A and V-shaped grooves 2 are made to face each other and are combined as shown in FIG. The applied thin film of silver solder is sandwiched between the core pieces 1.1a and heated under pressure from both sides of the iron core piece 1.1a to silver solder both iron core pieces. In this way, an iron core block having a plurality of continuous magnetic head iron cores is formed. This iron core block is shown in Figure 2 (
A) is cut along the plane shown by the chain line, and a plurality of pieces are cut along the plane shown by the chain line in FIG.
) The magnetic head core shown in ) is obtained. to this,
An excitation coil for passing a signal current is wound around the groove 4 on the side of the iron core piece 1a to complete a magnetic head produced by the manufacturing method of the present invention.

The third is a cross-sectional view of the completed magnetic head taken along a plane that crosses the magnetic gap 7 and is orthogonal thereto. Number 6 indicates the cross section of the excitation coil.

As is clear from the above description, the magnetic head manufactured by the manufacturing method of the present invention uses a magnetic material with high saturation magnetic flux density in the magnetic gap where magnetic flux concentrates and increases magnetic flux density. Since magnetic saturation is prevented, recording with increased signal strength is possible.

In addition, in the above embodiment, in order to simplify the manufacturing process, a sendust alloy layer is also applied to the joint surfaces of both cores, but there is no point in increasing the saturation magnetic flux density in this area. Of course, the present invention may be practiced without applying the sendust alloy layer to the joint between the two core pieces.

[Brief explanation of drawings]

FIGS. 1 and 2 are diagrams illustrating steps of a magnetic head manufacturing method according to an embodiment of the present invention. FIG. 3 is a sectional view of a magnetic head manufactured by the manufacturing method of the embodiment of the present invention. 1, la... Iron core piece 2 that makes up the magnetic head... ■
Mold groove 3... Sendust alloy layer 5... Magnetic pole portion of iron core piece 1a 6... Excitation coil 7... Si○2 layer constituting the magnetic gap Patent applicant
Sharp Co., Ltd. Agent, Patent Attorney Nishi 1) New Procedure Neho (Method) 1. Indication of the Case 1982 Patent Application No. 117122 2. Name of the Invention Method for Manufacturing a Magnetic Head 3. Case of Person Who Makes Amendments Relationship Patent applicant address: 22-22 Nagaike-cho, Abeno-ku, Osaka City Name (
504) Sharp Corporation Representative: Saeki Asahi 4, Agent address: 15-13-5, Usagano-cho, Kita-ku, Osaka City, Date of amendment order: October 26, 1980 (Shipping date): 6, Subject of amendment Details of the statement Document 1. Name of the invention Method for manufacturing a magnetic head 2. Claims In a method for manufacturing an iron core having a magnetic gap made of a non-ferromagnetic material in the magnetic circuit, two magnetic circuits are formed at a location other than the magnetic gap. Two core pieces made of a first ferromagnetic material are prepared, and the two core pieces are placed on the re-magnetized pole faces of these two core pieces, which face each other across the magnetic gap. , forming a magnetic layer made of a second ferromagnetic material having a higher saturation magnetic flux density than the first ferromagnetic material;
After forming a non-ferromagnetic material layer for forming the magnetic gap on the magnetic layer made of the second ferromagnetic material on the magnetic pole portion of at least one of the iron core pieces, A method of manufacturing a magnetic head, in which a magnetic circuit is formed by joining the magnetic circuit cross sections of the two iron core pieces. 3. Detailed Description of the Invention The present invention relates to a method for manufacturing a magnetic hesode. Recently, in order to increase the recording density on magnetic tape in video and audio magnetic recording devices, the size of magnetic particles applied to magnetic tape has become smaller and smaller.
The thickness of the magnetic fine particle coating layer and the thickness of the tape base material themselves tend to become thinner. Therefore, magnetic fine particle materials with a large coercive force Hc are now required, and currently home VTRs have a large coercive force Hc.
CrO2 tape or Co-T with about 700 millimeters of steel
-Fe203 tape is used. In addition, H c > 120, which is already in practical use in audio
The use of Oersted metal tape for video is also being considered. As the coercive force Hc increases, the residual magnetic flux density f3r generally increases, and in the case of metal tapes, Br is 3000, which is more than twice the value of conventional tapes.
It reaches ~4000 Gauss. Therefore, it is expected that the recording signal strength and the accompanying reproduction sensitivity will increase. However, in order to record with a high magnetic flux density, it is necessary to use a material with a high saturation magnetic flux density for the recording/recording magnetic head as well. In contrast, the saturation magnetic flux density (10,
Magnetic heads using alloys such as sendust or amorphous magnetic materials with a magnetic flux of 0.000 gauss or more are considered, but these materials have higher electrical conductivity than ferrite, and the higher the frequency, the more the effective penetration is reduced due to overcurrent effects. It has the disadvantage that it is difficult to manufacture a magnetic head for narrow trunks due to the decrease in magnetic flux and its brittleness. The purpose of the present invention is to combine the high saturation magnetic flux density characteristics of Sendust alloy and amorphous magnetic materials with the low electrical conductivity of ferrite magnetic materials conventionally used in magnetic head cores, and to achieve the performance of recent magnetic tapes. It is an object of the present invention to provide a method for manufacturing a magnetic head having a high saturation magnetic flux density that is commensurate with the improvement and whose characteristics do not deteriorate even in a high frequency region. For the above purpose, the method for manufacturing a magnetic head according to the present invention includes a first ferromagnetic material having a magnetic circuit divided into two at a location other than the magnetic gap of the magnetic head with which the magnetic head makes sliding contact. Prepare two iron core pieces consisting of the above-mentioned first ferromagnetic material, and place a magnet with a saturation magnetic flux density higher than the above-mentioned first ferromagnetic material on the re-magnetized pole faces of these two iron core pieces, which will face each other across the above-mentioned magnetic gap. forming a magnetic layer made of a highly magnetic second ferromagnetic material;
Furthermore, a non-ferromagnetic material layer for forming the magnetic gap is formed on the magnetic layer made of the second ferromagnetic material on the magnetic pole portion of at least one of the two iron core pieces. After that, the magnetic circuit is formed by joining the magnetic circuit cut surfaces of the two core pieces to form a magnetic circuit. Embodiments of the present invention will be described below based on the drawings. First of all, the main part of the magnetic path of the magnetic head is shown in FIG.
Two iron core pieces 1 and 1a as shown in A) are cut out of ferrite material, and in order to form the magnetic head pole part narrow in width corresponding to the track width of the magnetic tape, as shown in Fig. 1(B). After diagonally cutting V-shaped grooves 2 into both core pieces 1 and 1a, a film 3 of Sendust alloy having a high saturation magnetic flux density is deposited or sputtered on the side where the ■-shaped grooves 2 are cut. (Fig. 1 (C)) a
The film thickness is approximately 20 mm in consideration of the electrical conductivity of Sendust alloy.
By setting μ, the influence of overcurrent on effective magnetic permeability is ignored up to a frequency of 5 MHz. Furthermore, a groove 4 for winding the excitation coil is cut into one of the iron cores 1a as shown in FIG. A film of 5i02, which is a nonmagnetic material, is formed by vapor deposition or sputtering. (The Si02 film is not shown.) Next, the iron core piece 1 shown in FIG. 1(C) and the iron core piece 1 processed to the stage shown in FIG. 1(D)
A and V-shaped grooves 2 are made to face each other and are combined as shown in FIG. The coated thin film of silver solder is sandwiched between the iron core pieces 1.1a and heat is applied under pressure from both sides of the iron core piece 1.1a to silver solder both iron core pieces. In this way, an iron core block having a plurality of continuous magnetic head iron cores is formed. This iron core block is shown in Figure 2 (
A) is cut along the plane shown by the chain line, and a plurality of pieces are cut along the plane shown by the chain line in FIG.
) is obtained. to this,
An excitation coil for passing a signal current is wound around the groove 4 on the side of the iron core piece 1a, thereby completing the magnetic head produced by the manufacturing method of the present invention. FIG. 3 is a cross-sectional view of the completed magnetic head along a plane that crosses the magnetic gap 7 and is perpendicular thereto. Number 6 indicates the cross section of the excitation coil. As is clear from the above description, the magnetic head manufactured by the manufacturing method of the present invention uses a magnetic material with high saturation magnetic flux density in the magnetic gap where magnetic flux concentrates and increases magnetic flux density. Since magnetic saturation is prevented, recording with increased signal strength is possible. In addition, in the above embodiment, in order to simplify the manufacturing process, a sendust alloy layer is also applied to the joint surfaces of both cores, but there is no point in increasing the saturation magnetic flux density in this part. Of course, the present invention may be practiced without applying the sendust alloy layer to the joint between the two core pieces. 4. Brief Description of the Drawings FIGS. 1 and 2 are diagrams illustrating steps of a magnetic head manufacturing method according to an embodiment of the present invention. FIG. 3 is a sectional view of a magnetic head manufactured by the manufacturing method of the embodiment of the present invention. 1.1a... Iron core piece 2 composing the magnetic head... ■
Mold groove 3... Sendust alloy layer 5... Magnetic pole portion 6 of iron core piece 1a... Excitation coil 7... SiO2 layer constituting magnetic gap Patent applicant
Sharp Co., Ltd. Representative Patent Attorney Nishi 1) Shin

Claims (1)

[Claims] In a method for manufacturing an iron core having a magnetic gap made of a non-ferromagnetic material in a magnetic circuit, the magnetic circuit is divided into two at a location other than the magnetic gap, and the magnetic circuit is divided into two parts made of a first ferromagnetic material. Iron core pieces are prepared, and a second ferromagnetic material having a higher saturation magnetic flux density than the first ferromagnetic material is placed on both magnetic pole faces of these two iron core pieces that face each other across the magnetic gap. A magnetic layer made of a ferromagnetic material is formed, and the above 2.
1 from above the magnetic layer made of the second ferromagnetic material on the magnetic pole portion of at least one of the iron core pieces. A method of manufacturing a magnetic head, comprising forming a non-ferromagnetic material layer for forming the magnetic gap, and then joining the magnetic circuit cross sections of the two iron core pieces to form a magnetic circuit.