JPS61113108A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To improve a life of a magnetic head itself by insulating electrically a magnetic core itself and a coil by an insulation glass layer of the low melting point even when the coat of the coil is damaged at the groove-formed surface angle part. CONSTITUTION:In the butted surface of a pair of core blocks 21a and 21b, plural notch grooves 5 for regulating a track width are formed along the lengthwise direction angle part of the core block at the prescribed interval and a groove 8 for winding and a groove 6 for reinforcement are formed at one side core block 21a. After a low melting point glass rod 7 is placed at the notch groove 5, the groove 8 for winding and the groove for reinforcement, thermal treatment is executed for the glass rod 7, and the rod 7 is filled in the notch groove 5, the groove 8 for winding and the groove 6 for reinforcement. Next, the glass 7 protruded from the notch groove 5, the groove 8 for winding and the groove 6 for reinforcement is removed, and further, a mirror surface-shaped glass layer 7a is formed on the forming wall surface of the groove for winding. To the protruded surface of both blocks 21a and 21b, a high melting point glass layer 4 is covered, and thereafter, both blocks 21a and 21b are protruded, the melting temperature of low melting point glass is executed, the welding is executed and the coupling body is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a magnetic head used particularly in a VTR or the like.

[Conventional technology]

Conventional magnetic heads used in high-performance audio, VTR, etc. are made of a pair of rectangular parallelepiped core blocks made of ferrite or other ferromagnetic materials. Melting point glass, e.g. 3i
By injecting and filling the gap-forming space with glass made by adding the h component to Qz, or by heating and pressing the core block with glass foil interposed as a spacer on the same earthen floor,
Alternatively, after forming a glass thin film on the core block by sputtering, the glass layers are sandwiched and heat-pressed to join the core blocks, and then the core blocks are cut at predetermined intervals in the longitudinal direction. ing.

However, when low-melting glass is used for the gap, the gap width varies slightly depending on the strength of the bonding between the core blocks, making it difficult to determine the gap width accurately. ＜As a result, the characteristics of the magnetic head are degraded.

Therefore, a magnetic head as disclosed in Japanese Patent Laid-Open No. 57-58219 was developed. That is, as shown in FIG. 4, this magnetic head has two magnetic cores 31a of a predetermined shape,
A non-magnetic material with a relatively high softening point is arranged as a gap 32 between the abutting surfaces of the abutting surfaces of the magnetic cores 31a and 31t), and a non-magnetic material with a relatively low softening point is placed between the magnetic cores 31a and 31t) on the abutting surfaces other than the sandwiching surfaces. It is glued with 33. 34 is a winding groove, and 35 is a coil wound around the magnetic core 31a through the winding groove 34.

[Problems with conventional technology]

However, in the conventional magnetic head shown in FIG. 4, there is a risk that the wound coil 35 may rub against the corners of the surface where the winding groove 34 is formed and the coil coating may be damaged. Coil 35 and magnetic core 31 whose coatings were damaged because no insulation treatment was applied to the forming surfaces.
There was a problem in that the contact between the magnetic head a and the magnetic head 34 at the corner of the winding direction 34 caused poor insulation, significantly shortening the life of the magnetic head itself.

The object of the present invention is to solve such problems and to provide a strong connection that has a gap of a desired width, but does not cause direct electrical contact between the magnetic core and the coil even if the coil coating in the winding groove is damaged. It is an object of the present invention to provide a method for manufacturing a magnetic head that has the following characteristics.

[Means for solving problems]

To solve the above problems, the present invention forms a winding groove in the longitudinal direction on at least one core block side in the abutting surfaces of a pair of rectangular parallelepiped core blocks made of magnetic material, and A plurality of notch grooves are formed at predetermined intervals along the longitudinal direction in each abutting portion of the core block located on one side with respect to the direction,
After filling the plurality of notch grooves and the winding groove with low melting glass, the low melting glass portion in the winding groove is cut to form a thin low melting point glass layer on the groove forming surface. Then, a high melting point glass for forming a gap is deposited on the abutting surface of at least one of the pair of core blocks by means such as vapor deposition or sputtering. The core block is characterized in that it is integrated by heat treatment at a melting temperature, and the integrated product is cut into a desired shape by cutting in the lateral direction of the core block at each of the notched grooves.

The low melting point glass has an insulating property and strengthens the bond between the pair of core blocks, and the material is not particularly limited as long as it has a melting point lower than the high melting point glass forming the cap. For example, when 8i02 is used as the high melting point glass, a glass with a pb acid component added to si02 is used as the low melting point glass.

Further, in the method of the present invention, in order to uniformly leave the low melting point glass formed as a thin layer in the winding groove on the surface where the winding groove is formed, when the pair of core blocks are integrated by low melting point glass welding. It is preferable to join the core blocks while rotating them.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

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

la and lb are magnetic cores (hereinafter referred to as cores) that are roughly in the shape of an opening, and a hollow hole is formed in the center of the cores la and lb so that a closed magnetic path is formed in the cores la and lb during recording and reproduction. Section 2 is provided. A gap 3 is formed between the abutting surfaces of the cores la and lb. The gap 3 is made of a glass layer, and the cores la and lb are welded to the glass layer with glass 7 filled in the track width regulating notch 5 and reinforcing groove 6. core la, lb
A thin layer 7a made of the same glass as the glass film filled in the notch groove 5 and reinforcing groove 6 is formed almost uniformly on the wall surface of the hollow part 2, and the coil 9 is wound through this hollow part 2. It is wound around the side core 1a forming the wire groove 8 with the glass layer 7a interposed therebetween.

2(a) to 2(j) are process diagrams showing the manufacturing process of the magnetic head 1 of the present invention, in which 21a shown in FIG.
A pair of core blocks 121b are made by cutting a magnetic material such as ferrite into a desired rectangular parallelepiped shape. At the abutting surfaces of the pair of core blocks 21a and 21b,
As shown in FIG. 2(b), a plurality of notch grooves 5 for regulating track width are formed along the longitudinal corners of the core block at predetermined intervals, and a winding groove is formed in one core block 21a. 8 and reinforcing grooves 6 are formed. In the detailed description of the present invention, the winding wire @8 and the reinforcing groove 6 are formed in one block 21a, but they may be formed in 21b of both blocks 21a.

Further, the winding groove 8 and the reinforcing groove 6 may be formed in separate blocks 21a and 21b, respectively. Note that the reinforcing groove 6 does not necessarily have to be formed.

Then, as shown in FIG. 2(C), a low melting point glass rod 7 made of, for example, 5i02 with a papermaking component added thereto, is placed in the notch groove 5, the winding groove 8, and the reinforcing groove 6. The rod 7 is heat-treated to fill the cutout groove 5, the winding groove 8, and the reinforcing groove 6 with glass 7 so as to protrude outward as shown in FIG. 2(d).

Next, as shown in FIG. 2(e), the glass 7 protruding from the notch 5, the winding groove 8, and the reinforcing groove 6 is removed by, for example, polishing, and then the inside of the winding groove 8 is removed. The glass 7 is cut using, for example, a forming grindstone, and a mirror-like glass layer 7a having a thickness of about 20 to 30 μm is formed on the wall surface where the winding groove 8 is formed as shown in FIG. 2(f). .

Then, a high melting point glass such as 3iQz is deposited on the abutting surfaces of the blocks 21a and 21b by vapor deposition, sputtering, or equivalent means to a thickness equal to the desired gap width, as shown in FIG.
g) After coating the high melting point glass layer 4 shown with diagonal lines in the middle,
As shown in FIG. 2(h), both blocks 21a, 21
Match b. Then, heat treatment is performed at the melting temperature of low melting point glass to fuse both blocks 21a121b with the filling glass 7 to form a combined body. In addition, where high melting point glass and low melting point glass touch,
High melting point glass is assimilated to low melting point glass.

Next, as shown in FIG. 2 (see Figure 2), cut the parts of each notch groove 5 of this assembly to a predetermined width in sequence, and cut the unnecessary lower part from the reinforcing groove 6. A core l of a predetermined shape as shown in FIG. 2(j) is cut out.
A magnetic head 1 having a and lb is obtained.

In the magnetic head 1 thus obtained, the tape sliding surface is ground in a circular arc shape and lapped in a subsequent step, and the hollow portion 2 formed by the winding groove 8 is polished.
A coil 9 is wound around. Figure 3 shows a cross section of the main part of the magnetic head 1 manufactured by the manufacturing method of the present invention. with a gap of desired width consisting of
Moreover, a winding groove for forming a closed magnetic path of the magnetic head is formed. A strongly coupled magnetic head with a thin insulating glass layer formed on the wall surface can be easily manufactured. Therefore, in the magnetic head manufactured by the method of the present invention, even if the coating of the coil wound around the magnetic core through the winding groove is damaged at the corner of the surface where the winding groove is formed, the insulating glass layer protects the magnetic core from being damaged. Since the magnetic head and the coil are electrically insulated, there is a significant advantage that the life of the magnetic head itself is improved.

[Brief explanation of drawings]

1 to 3 are diagrams for explaining one embodiment of the method of the present invention. FIG. 1 is a perspective view showing a magnetic head obtained by the method of the present invention, and FIGS. '') is a diagram showing an example of the manufacturing process of the method of the present invention, FIG. 3 is a sectional view of a main part of a magnetic head, and FIG. 4 is a perspective view showing a conventional magnetic head. 1... Magnetic head la, lb... Core block 3... Gap 4... Glass layer 5 forming the gap Notch groove 6... Reinforcement groove 7... Low melting point glass 8... Coil Winding groove 9...Coil 7a...Low melting point glass layer Patent applicant Alfus Electric Co., Ltd. Fig. 2 (α) dl (rl) tJt) 1b (Jn Takagame Fig. 3 Fig. 4

Claims (2)

[Claims] (1) A winding groove is formed in the longitudinal direction of at least one of the core blocks on the abutting surfaces of a pair of rectangular parallelepiped core blocks made of a magnetic material, and a winding groove is formed on one side of the winding groove. After forming a plurality of cutout grooves at predetermined intervals along the longitudinal direction of each abutting portion of the core block, and filling the plurality of cutout grooves and the winding groove with low melting point glass. , Cutting the low melting point glass portion in the winding groove to form a thin low melting point glass layer on the groove forming surface, and then cutting the low melting point glass portion on the abutting surface of at least one of the pair of core blocks. A high melting point glass for gap formation is attached by means such as vapor deposition or sputtering, and then the pair of core blocks are butted together and integrated by heat treatment at the melting temperature of the low melting point glass, and the integrated product is formed into the notch. A method of manufacturing a magnetic head, which comprises cutting a core block in the lateral direction for each groove to form a desired shape. (2) The method of manufacturing a magnetic head according to claim 1, wherein when the pair of core blocks are integrated by low-melting glass welding, the core blocks are joined while being rotated.