JPS63213111A - Method for forming gap of magnetic head - Google Patents

Abstract

PURPOSE:To remove an angular moment generated in an azimuth core and to form a gap with a few amount of gap length distribution even in the gap formation of the core half body of a large area core, by providing a back plane groove on the half body, a pair of which form a magnetic head. CONSTITUTION:The core half body 1a consists of a non-magnetic substrate 5, a winding groove 4, a glass layer 3, and an amorphous thin film 2, etc., and the back plane groove 6 which pressurizes only a substrate on which the amorphous thin film is filmed is provided on the back plane of the core half body. Also, the similar back plane groove 6 is provided on the half body 1b, and it follows that it pressurizes a projecting part generated by the working of both back plane grooves, thereby, the angular moment generated by the azimuth can be eliminated. Also, pressurization in a direction orthogonal to a pressurizing jib can be obtained, and it is possible to perform gap formation with a few amount of gap length distribution and high accuracy even in the gap formation of the core half body of large area in which a head core is arranged two-dimensionally. And since it is possible to reduce influence on a gap length even for the fine movement of a bonding layer, and also, to eliminate the groove working of a gap plane, the working with the same number of processes as that of a conventional method can be performed even when the groove working of the back plane is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for forming a gap in a magnetic head used in digital audio, video tape recorders (VTR), and the like.

BACKGROUND OF THE INVENTION In recent years, trends in magnetic recording have been such that, as video heads and the like are required to have characteristics in a high frequency range, magnetic heads and recording media that can adequately handle submicron recording wavelengths have been desired.

Under these current circumstances, magnetic head materials are made of magnetic alloys (with a higher saturation magnetic flux density BS) than nonmetallic materials such as ferrite in order to perform sufficient writing on recording media (for example, metal tapes) with high coercivity Hc. For example, an amorphous material (Sendust) is being developed.

In addition, as the recording track width becomes narrower due to higher density manufacturing methods, metal heads using amorphous thin films and amorphous ribbons are being put into practical use. As a measure,
Attempts have been made to create a large number of umbilical cords at once by forming a gap between the head cores by arranging them two-dimensionally.

Hereinafter, a conventional method for forming a gap in a magnetic head will be described with reference to the drawings.

FIG. 4 shows core halves 10a and 10 in the manufacturing process of a head in which the magnetic alloy serving as the main magnetic path is an amorphous thin film.
b.

An amorphous film 12, which will become the main magnetic path of the head, is formed on a non-magnetic substrate 1) by sputtering, etc., and then laminated and bonded with a glass film 13, which will become an adhesive layer.As shown in the figure, a core semi-circular structure with an azimuth of 20° is formed. ioa, i.

It was processed as b. The core half 10a is provided with a winding groove 4, and the core half 10b is provided with a gap surface groove 15.

A non-magnetic film (not shown in the figure), such as 5iOZ or glass, serving as a gap material is formed by sputtering on the gap abutting surfaces of the core halves 10a and 10b.

FIG. 5 is a gap formation diagram of a half-core core.

The core half 10a shown in FIG. 4 has a non-magnetic film deposited thereon.

], while pressing Ob with the gap forming jig 16, winding to increase the adhesion between both cores, v! A glass rod 18 is inserted into the apex portion 17 of the groove 14. This is placed in an electric furnace and each half of the core is glued together, completing the formation of the gear and valve.

In 81 video tape recorders and digital audio, the target gap length is extremely small, around 0.3 .mu.m, and strict accuracy is required, such as the allowable width of, for example, ±0.03 .mu.m.

To ensure gap length accuracy, extremely high-precision processing technology is required for the core half-hole itself, including the parallelism in the thickness direction of the core half-hole, the flatness of the gap abutting surfaces, and the thickness distribution of the non-magnetic film that serves as the gap material. Furthermore, when forming the gap, it is necessary to apply appropriate and even pressure to the entire surface where the half cores abut against each other. However, when the head core is arranged two-dimensionally like the core halves 10a and 10b shown in FIG. This method has disadvantages in that processing accuracy deteriorates and it becomes difficult to apply uniform pressing force even when forming a gap.

Problems to be Solved by the Invention Problems in the conventional gap formation of core half-holes that are two-dimensionally arranged and machined with an azimuth of 20° are, firstly, that the core half-holes have an inclination of 20'', so surface machining is difficult. When pressure is applied, the pressure applied to the half core is a force acting in a direction perpendicular to the pressure surface, and a rotational moment acting in the azimuth direction due to the loosening of the bonded glass at high temperatures, resulting in multi-layer laminated bonding. This causes a large amount of stress to be applied to the adhesive layer, which causes the substrate to peel off in the adhesive layer.Secondly, due to the slight movement of the core, the gap length distribution is larger than the required accuracy.Thirdly, the gear rep surface Grooving has a problem in that it cannot be expected to be effective in obtaining uniform pressing force.

Means for Solving the Problems In the present invention, in order to solve the above-mentioned problems, the gap surface groove processing is eliminated, and a back groove is provided for pressurizing only the substrate on which the amorphous thin film is to be deposited on the back surface of both core halves. ,
The rotational moment generated in the azimuth direction is controlled to obtain an appropriate gap length.

Effect The present invention is capable of applying a load evenly and without rotational moment to the gap portion, which is the point, even when the head core is two-dimensionally arranged and a large-area gap is formed with the core partially closed. , the gap length distribution can be made small, and a magnetic head with a high yield rate can be manufactured.

Example Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows a half-finished core on which the back surface grooves of the present invention have been processed.

la, lb are core half-rest trying to form a gap, 2
3 is an amorphous thin film, 3 is a glass layer serving as an adhesive layer, 4 is a winding groove to be processed into the core half 1a, 5 is a nonmagnetic substrate, and 6 is a back groove of the present invention.

Moreover, FIG. 2 is an enlarged view of a schematic part during pressurization.

7a and 7b are amorphous film-deposited substrates, 8a and 8b are glass film-deposited bases serving as adhesive layers - temporary, 2 is an amorphous thin film, and 3
6 is a glass adhesive layer, 6 is a back groove of the present invention, and 9 is a pressing jig.

This method pressurizes the protrusion created by back groove processing without performing conventional gap face groove processing, and it is possible to eliminate the rotational moment generated by azimuth, and even if there is slight movement in the adhesive layer, only the amorphous film-coated substrate can be applied. Since it is pressed, the influence on the gap length can be reduced, and the gap can be formed with a pressing force in a direction perpendicular to the pressing jig.

FIG. 3 shows the distribution of gap length accuracy when the back surface groove processing of the present invention is performed to form a gap with a half gap in the core of the amorphous head shown in FIG.

The average value of the gap length is a value suitable for the thickness of the gap material formed on the gap abutting surfaces, and the distribution almost satisfies the required accuracy.

In this embodiment, an amorphous alloy and a non-magnetic substrate are used, but the present invention is not limited to this, and can be applied to a method of manufacturing a magnetic head obtained using various combinations such as a sendust alloy and a magnetic substrate.

Effects of the Invention As described above, the present invention firstly removes the rotational moment generated in the azimuth core by cutting grooves on both back surfaces of the core halves that form a pair of magnetic heads, and pressurizing only the protruding portions that are formed. At the same time, pressure can be obtained in the direction perpendicular to the pressure jig, and high-precision gap formation with a small gap length distribution can be achieved even when forming a large-area half-core gear with a two-dimensional head core arrangement. can.

Secondly, since the amorphous film-coated substrate is pressurized against slight movement of the adhesive layer, the influence on the gap length can be reduced and the same effect can be obtained.

Thirdly, since the gap surface groove processing can be omitted, even if the back surface groove processing is performed, the processing can be performed with the same number of man-hours as in the conventional method.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a core half-opened with grooves on the back surface according to an embodiment of the present invention, FIG. A distribution diagram comparing the gap length distribution due to the gap formation of the invention with that of the conventional method. Fig. 4 is a perspective view showing a conventional core half-hole that is two-dimensionally arranged and processed. FIG. la, lb...Core half-dead, 2...Amorphous thin film, 3...Glass layer, 4...
・Winding groove, 5...Gap surface groove, 6a, 6b・
...Back groove. Name of agent: Patent attorney Toshio Nakao 1 person Figure 3 No. OA, TOE - Core Teiki / 4-Ichiro" 1

Claims (4)

[Claims] (1) A magnetic head characterized by a composite substrate in which a magnetic alloy serving as the main magnetic path and a non-metallic non-magnetic material substrate are bonded together by pressure bonding, and grooves are formed on the back surfaces of both core bars that form a pair of magnetic heads and the core bars are bonded by pressure bonding. gap formation method. (2) A method for forming a gap in a magnetic head according to claim (1), using an amorphous material as the magnetic alloy. (3) A method for forming a gap in a magnetic head according to claim (1), using Sendust as the magnetic alloy. (4) A method for forming a gap in a magnetic head according to claim (1), wherein a non-metallic magnetic material is used as the substrate.