JPH01260609A - Composite magnetic head and its manufacture - Google Patents

Abstract

PURPOSE:To reduce an eddy current loss in a high frequency region, and to easily and precisely set track width by forming a multilayered magnetic film with high saturation magnetic flux density in a groove which is wider in width than the track widths at both the sides of a gap surface and in addition, is parallel with the gap surface and extends over its whole length. CONSTITUTION:The multilayered magnetic film consisting of a metallic magnetic film 3 and an insulation film 11 is formed in the groove 4 which is positioned at both the ends of a pair of core halves 1a, 1b as interposing a winding widow 9 part, a gap 8 surface and the gap and is wider in the width than the track width and is parallel with the gap surface and extends over the its whole length. Thus, the deterioration of a magnetic characteristic due to the eddy current loss due to the film thickness of the magnetic film can be reduced even in use for several tens of MHz, and in addition, since the grooves for regulating the track width Tw are worked on both the right and the left sides of the multilayered film of the metallic magnetic film 8 and the insulation film 11 by a grooving wheel, the track width Tw can be easily and precisely regulated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a composite magnetic head and a manufacturing method thereof;
In particular, the present invention relates to a composite magnetic head that has a magnetic core made of a non-magnetic material and a metallic magnetic material with a high saturation magnetic flux density, and records and reproduces signals on a high coercive force medium such as a metal tape.

[Conventional technology]

In recent years, in magnetic recording technology, high coercive force media (for example, metal tapes) have been used due to the demand for high-density recording. Conventional high magnetic permeability ferrite is insufficient for recording signals on this high coercive force medium, and as shown in FIGS. 4 and 5, a high magnetic permeability ferrite 12 and a metal magnetic film 3 having a high saturation magnetic flux density are used. For example, a composite magnetic head combining Sendust and a Co-based amorphous alloy has been developed (see, for example, Japanese Patent Laid-Open No. 11909/1983).

The composite magnetic head has glass 5a, 5b molded to a predetermined thickness on the recording medium contacting surface 7 side of a pair of core halves 1a, lb facing each other with a gap (G) in between. After forming a groove, a metal magnetic film 3 is deposited by sputtering so that the groove 4 is completely filled. In such a magnetic head, the metal magnetic film 3 is extended in the direction P perpendicular to the gap (G), and a bonding surface between the metal magnetic film 3 and the high magnetic permeability ferrite 12 is formed in a portion corresponding to the track width of the recording medium contact surface 7. By preventing this from appearing, contour effects can be prevented during playback. Note that 8 is a gap made of a non-magnetic material such as 5 in 2° Al2O2. 9 is a coil (not shown)
10 is the winding window for winding the core half body 1a, lb
This is bonded glass for welding.

[Problem to be solved by the invention]

In the conventional composite magnetic head and its manufacturing method as described above, since the metal magnetic film 3 in the track width portion of the metal magnetic film for recording and reproducing signals is a single layer film, when used in a high frequency region, vortex There was a problem in that the magnetic properties deteriorated due to current loss, and the reproduction output of the magnetic head decreased. In addition, the track width Tw of the metal magnetic film is determined by the width of the foil (grinding wheel) used to groove the reinforced glass, so the track width Tw
There was a problem that regulations were extremely difficult and variations occurred. This invention was made to solve the above-mentioned problems, and it is a highly reliable composite magnetic that can reduce eddy current loss in metal magnetic films in high frequency ranges and accurately regulate track width. The object of the present invention is to provide a head and a method for manufacturing the same.

[Means to solve the problem]

A composite magnetic head according to the present invention includes a winding window portion of a pair of core blocks made of a non-magnetic material or ferrite;
A multilayer magnetic film consisting of a metal magnetic film and an insulating layer is formed on the gap surface and in a groove wider than the track width and parallel to the gap surface and extending the entire length at both ends of the gap.

Further, in the manufacturing method of the composite magnetic head, the multilayer magnetic film is simultaneously formed on the gap surface 9 winding groove portions and the entire surface of the groove portion, and the multilayer magnetic film portion corresponding to the track of the recording medium has a track width. This is characterized in that the track width is formed to a predetermined width by providing regulating grooves.

[Effect]

According to this invention, since the metal magnetic film on the recording medium abutting surface is made into a multilayer magnetic film with an insulating layer interposed therebetween, it is possible to reduce eddy current loss due to the thickness of the metal magnetic film in the high frequency region, and improve the reliability of the magnetic head. can be improved. In addition, the groove for sputtering the metal magnetic film on the recording medium contact surface is made wider than the track width, and the track width can be set arbitrarily using a groove processing foil, making it possible to regulate the track width with high precision. be able to.

〔Example〕

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

FIG. 1 is a perspective view showing the structure of a composite magnetic head according to an embodiment of the present invention, and FIG. 2 is a plan view of FIG. 1. In the figure, la and lb are half core blocks, 2 is a non-magnetic material, and 3 is a magnetic metal film, which is made of sendust, amorphous metal alloy, etc., for example. 8 records the signal on the recording medium.

A gap made of non-magnetic material such as 5iOz and Al2O2 for regeneration, and 4 a core block half la.

This is a groove provided in the recording medium abutting surface 7 of the groove 4, and extends over the entire length on both sides of the gap 8 in parallel to the surface of the gap 8. ) The metal magnetic film 3 is sputtered on the gap surface and the portion corresponding to the track. 9 is a winding window for winding the coil, 10 is a glass for joining the core block halves, and 11 is an insulating layer for forming the alloy magnetic film 3 in multiple layers, and is made of a non-magnetic material such as 5i02. Consists of.

Next, a method for manufacturing the above composite magnetic head will be explained in order of steps with reference to FIGS. 3(a) to 3(f).

First, in the step shown in FIG. 3 (al), grooves 9 for winding windows are formed in the gap surface 20a of the core block half body 1a made of a non-magnetic material, and the gap surfaces 2Qa of the core block halves la, lb are formed. A plurality of grooves 4a to 4d are formed parallel to 20b and wider than the track width Tw, and the gap surface 20a,
Polish 20b.

Next, in the step shown in FIG. 3(b), alloy magnetic films 3a, 3b and insulating layers 11a, llb are alternately sputtered simultaneously on the gap surfaces 20a, 20b, the grooves 4a to 4d, and the entire surface of the winding window 9. , forming a multilayer magnetic film.

Next, in the step of FIG. 3(C), the grooves 4a to 4d are adjusted so that the width of the multilayer magnetic film formed in the grooves 4a to 4d becomes a predetermined track width.
Grooves 30a to 30d for track width regulation on both sides of a to 4d
After forming and filling the non-magnetic material, the gap surfaces 40a, 4
After polishing 0b, the non-magnetic material SiOz, Al2
Sputter a gap material such as O2 onto the gap abutting surfaces (not shown).

Next, in the process of FIG. 3 Fdl, the core block half la,
Align the track widths Tw of lb and insert the glass rod 1
0 into the winding window 9, the glass rod 1° is melted and the core block halves 1a and lb are joined and integrated.

After that, in the step shown in FIG. 3(e), the core block half la
, lb are cut along dashed lines M and N, and in the process of FIG. 3 (fl), a predetermined coil (
(not shown), a composite magnetic head for recording and reproducing signals on a recording medium is completed.

According to this embodiment, the magnetic film for recording and reproducing signals is made of a multilayer film consisting of the metal magnetic film 3 and the insulating film 11, as described above, so that even when used at several tens of MHz, the magnetic film remains stable. Deterioration of magnetic properties due to eddy current loss due to film thickness is reduced, and a high quality and highly reliable magnetic head can be obtained. In addition, grooves for regulating the track width Tw are formed on both left and right sides of the multilayer film of a metal magnetic film and an insulating film embedded in the groove 4 having a width equal to or larger than the track width Tw. , the track width Tw can be easily and accurately regulated.

Although the above embodiment describes the case where the gap (G) has no azimuth, the technical idea of the present invention is not limited to this, and the present invention also applies to the video head throat gap (C).
, ) has an azimuth.

Further, in the above embodiment, the core block half body 1a.

Although a non-magnetic material is used for 1b, a high magnetic permeability ferrite may be used instead, and the same effect as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, since the magnetic material made of a metal with a high saturation magnetic flux density suitable for combination with a high coercive force medium is made into a multilayer magnetic film with an insulating layer, the thickness of the metal magnetic film can be increased in the high frequency region. In addition, the grooves for sputtering the multilayer magnetic film are formed wider than the track width, and the track width can be set arbitrarily using the groove processing foil, making it easy to adjust the track width with precision. Well configurable,
A highly reliable composite magnetic head can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the structure of a composite magnetic head according to an embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG.
a) to (f) are diagrams showing the manufacturing process of the composite magnetic head shown in FIG. 1, FIG. 4 is a perspective view showing a conventional magnetic head, and FIG.
The figure is a plan view of FIG. 4. la and lb are half core blocks, 2 is a non-magnetic material, 3 is a metal magnetic film, 4 is a groove, 5 is glass, 7 is a recording medium contact side,
8 is a gap, 9 is a winding window, IO is a bonding glass, 11 is an insulating film, 12 is a high permeability ferrite, 20 a, 2
0 b, 40 a, 40 b are gap surfaces, 3
0a to 30d are grooves. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (2)

[Claims] (1) In a magnetic head in which a pair of opposing core block halves are made of a non-magnetic material or ferrite and have a magnetic film for recording and reproducing signals, a gap surface of the core block halves, a winding window portion, A multilayer magnetic film consisting of a metal magnetic film with high saturation magnetic flux density and an insulating layer is formed in a groove wider than the track width and parallel to the gap surface and extending the entire length on both sides of the gap surface. A composite magnetic head with (2) In a magnetic head having a magnetic film for recording and reproducing signals, a winding window is provided on the gap surface of a pair of half core blocks made of non-magnetic material or ferrite, and a winding window is provided wider than the track width and parallel to the gap surface. A first groove forming a groove extending the entire length.
a second step of simultaneously forming a multilayer magnetic film by alternately sputtering a metal magnetic film with a high saturation magnetic flux density and an insulating layer on the winding window, the gap surface, and the entire surface of the groove; a third step of forming track width regulating grooves on both sides of the multilayer magnetic film to form the multilayer magnetic film so as to have a predetermined track width; and a fourth step of butting and joining the composite magnetic heads.