JPS60237609A - Magnetic head - Google Patents

Abstract

PURPOSE:To obtain an excellent recording and reproducing characteristic for a high-coercive force recording medium by using a magnetic alloy which consists of multi-layered films via intermediate layers constituted of >=2 layers of multi- layered films having 0.01-0.2mum. CONSTITUTION:The butt part of ferrites 20, 20' has a V-shaped projection and the magnetic alloys 21, 21' are formed to the projecting part. The magnetic alloy films are formed to 20mum and consist of the multi-layered films of four layers each at 5mum. The multi-layered films have the multi-layered structure formed with 0.05mum insulators or magnetic materials as the intermediate material. A working gap 23 is formed to the butt surfaces of the alloy 21, 21' and is formed via a sputtered film. A nonmagnetic joining material 22 joins and fixes a pair of core halves.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic head for magnetic recording and reproduction, and particularly to a magnetic head made of a composite material suitable for high-density magnetic recording.

[Background of the invention]

A magnetic head suitable for use in combination with a high coercive force magnetic recording medium is constructed using a magnetic alloy with a high saturation magnetic flux density to effectively magnetize a high coercive force magnetic recording medium at a short recording wavelength. Magnetic recording can be performed.

In consideration of practical aspects, in such a magnetic head, only the tip portion of the head chip where magnetic saturation is a problem is constructed with a magnetic alloy film having a high saturation magnetic flux density B8, and the other parts of the head chip are made of a magnetic alloy film with a high saturation magnetic flux density B8. A magnetic head constructed using ferrite having excellent properties has been proposed.

One example is constructed as shown in FIGS. 1(a) and 1(b), respectively, showing its top and side views. That is, the main magnetic circuit 10.10' of the magnetic head is made of high magnetic permeability ferrite, and the part forming the working gap gL is made of a magnetic alloy film 11.11' having a high saturation magnetic flux density.
The magnetic alloy film is 12.12' and ferrite 10.
．． 10' to form a ring-shaped magnetic circuit having a coil winding window 13. Furthermore, magnetic alloy film 1
1.11' and ferrite 10.10' joint 12.
12' is parallel to the opposing surface of the working gap gL, so that the magnetic alloy film 11.11' and the ferrite 10.1
0' have different values, the two joints 12.1 sandwiching the working gap g□
2' may exhibit a pseudo-gap effect, which has the drawback of impairing recording and reproducing characteristics.

As an example of solving the above drawbacks, a magnetic head constructed as shown in FIGS. 2(a) and 2(b), respectively, has been proposed. That is, the main magnetic circuit 10.10' of the magnetic head is made of high magnetic permeability ferrite, and the portion forming the operating gap gt is made of a magnetic alloy film 11.11' having a high saturation magnetic flux density. The films are connected to the ferrite 10 and 10' at surfaces 12 and 12'' obliquely intersecting the working gap, respectively, and the magnetic alloy film 11
．． 11' and the ferrite 10, 10' are prevented from affecting the recording/reproducing characteristics in the working gap gL. Such a magnetic head has good characteristics, but when a magnetic heptagonal alloy film is used, a method is used in which it is multilayered with an electrical insulating film interposed therebetween in order to ensure high frequency characteristics. However, in the magnetic head structure shown in FIG. 2, experiments have revealed that the structure and material of the intermediate film constituting the multilayer film pose problems. FIG. 3 shows an example of an enlarged plan view of the surface facing a recording medium of a magnetic head having multiple layers of magnetic alloy films. In FIG. 3, 10.10' is a ferrite film, 11.11' is a magnetic alloy film, and 14°14' is an intermediate layer (Sin2 film) used for multilayering. In a magnetic head having such a structure, when the magnetic alloy film is multilayered with an insulating material as an intermediate layer, there is a drawback that increasing the thickness of the insulating intermediate film reduces the efficiency of magnetic flux flow and deteriorates recording and reproducing characteristics. Furthermore, it has been found that when an intermediate layer is formed, the film thickness at 15.15', which is the protrusion, is thicker than other parts, resulting in the appearance of a pseudo-gap effect.

[Purpose of the invention]

An object of the present invention is to eliminate the above-mentioned conventional drawbacks and to provide a magnetic head that exhibits excellent recording and reproducing characteristics even on high coercive force recording media.

[Summary of the invention]

In the present invention, a magnetic alloy having high saturation magnetic flux density and high magnetic permeability is coated on at least both sides of the protrusions of two protective cores each having a protrusion having a 7-shaped cross section on the surface facing the magnetic recording body. In a magnetic head in which the magnetic alloy films are deposited and face each other across an operating gap at the tip of the protrusion to form a magnetic circuit, the magnetic alloy is made of a multilayer film with an intermediate layer interposed therebetween; The intermediate layer has a thickness of 0.01 μm=0.
By making it a multilayer film of two or more layers of 1 μm,
The pseudo gap effect caused by the intermediate layer can be avoided, and recording and reproducing characteristics with excellent high frequency characteristics can be obtained. When the thickness is less than 0.01 μm, the effect of the intermediate layer cannot be obtained, and the reproduction output in the high frequency region decreases. Further, when the intermediate layer is an insulator, if the thickness is 0.1 μm or more, a pseudo gap effect will appear in the head structure of the present invention, which is not preferable. On the other hand, if the intermediate layer is made of a magnetic material, 0.
The pseudo gap effect does not appear up to about 15 μm. If it is more than that, the magnetic properties of the magnetic material in the intermediate layer may appear, which is not preferable. Preferably 0.02μm to 01μm
This is achieved by an intermediate layer consisting of m.

The intermediate layer of the present invention is composed of an electrical insulator such as S i 02 HA n 20B, and other ceramics and high melting point glasses can be used. We have also discovered that excellent magnetic properties are exhibited when the intermediate layer is made of a magnetic material.

The intermediate magnetic layer has G o , N i , F a ,
A metal magnetic material such as a Ni-Fe alloy or a Fe-AQ-Si alloy, an amorphous magnetic alloy, a thin film ferrite, or the like is used.

A magnetic material having a high saturation magnetic flux density (Bs≧8000 Gauss) is suitable for the magnetic alloy formed in the protrusion of the protective core of the present invention. Preferably, an amorphous magnetic alloy that does not have a columnar crystal structure in a thin film is suitable. In particular, this is advantageous because the problems of film cracking and peeling at the tips of protrusions and the bottoms of grooves do not occur with amorphous magnetic alloys. Furthermore, particularly suitable characteristics can be obtained in which the thickness of one layer is 2 μm to 10 μm.

The protective core of the present invention uses a material with higher sliding strength than the magnetic alloy film in order to ensure wear resistance.

Excellent magnetic head characteristics can be obtained by configuring a magnetic circuit by combining a Mn-Zn-based or N1-Zn-based high permeability ferrite and a magnetic alloy film. Furthermore, by constructing the magnetic circuit with a magnetic alloy film and making the protective core a nonmagnetic material such as nonmagnetic ferrite or ceramic, a magnetic head with low sliding noise can be obtained. In this case, the magnetic alloy film goes around inside the coil winding window formed in the protective core to form a magnetic circuit.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 4 is a top and side plan view of a magnetic head showing an embodiment of the present invention. In the figure, 20°20' is M n
-Z n ferrite is formed, the abutting part has a V-shaped protrusion, and the protrusion has a magnetic alloy 21.21' (
For example, it is formed by sputtering an amorphous alloy of Co, Nb12Zrs). The magnetic alloy film is approximately 20 μm thick and consists of a multilayer film of 4 5 μm layers. The multilayer film is an insulator such as S 10x + A 020s or N i . Fe=. It has a multilayer structure in which one type of magnetic material such as , Ni, or Go is formed as an intermediate film with a thickness of 0.05 μm.

Reference numeral 23 indicates a working gap, which is formed on the abutting surfaces of magnetic alloys 21 and 21', and has a sin of about 0.3 μm.

Manufactured using a sputtered film. 22 is a non-magnetic bonding material for bonding and fixing the pair of core halves, and is filled with glass. 24 is a window for coil winding. The magnetic circuit is made of a magnetic alloy with a high saturation magnetic flux density in the vicinity of the operating gap, and is formed of a bonding material bonded to ferrite. Further, in a top view of the surface facing the recording medium, the magnetic core edge portions other than the working gap have a structure that is oblique so that there is no parallel part to the working gap.

FIGS. 5 and 6 are enlarged top views of the magnetic helad core, explaining in detail an example of the multilayer structure of the magnetic alloy of the present invention. The numbers added in the figures are the same as in FIG. 4. The magnetic alloy film 21, 21' consists of a multilayer film of two or more layers,
The thickness of one layer is 2 μm to 10 μm. In FIG. 5, 25.25' indicates one of the intermediate layers, and each intermediate layer has a layer thickness of 0.01 to 0.1 μm. Also, the top of the protrusion in FIG. 6 20' is rounded. The present invention can also be applied to such a shape.

FIG. 7 is a side plan view of a magnetic head showing another embodiment of the magnetic head of the present invention. Ma head is made of magnetic alloy 2
1.2.1' connects the coil winding window 24 through the working gap
It orbits around to form a magnetic circuit. In this case, the ferrite portions 20, 20' can be made of a non-magnetic material. This has the advantage that sliding noise can be reduced.

Figure 8 shows the magnetic alloy 21.2 from the magnetic herad core in Figure 7.
A perspective view of the magnetic circuit when 1' is taken out is shown.

Next, FIG. 9 shows a comparison of the recording and reproducing characteristics of the magnetic head of the present invention and the conventional example. FIG. 9 shows reproduction output characteristics with respect to frequency characteristics measured with a VTR device using a recording medium with a coercive force of 14000e. The reproduction output characteristics shown are for the magnetic alloy film 20.
It is shown as a relative value based on curve 30 of the reproduction output characteristics of a magnetic head using a composite material of a μm single layer film and Ferrai i. Curve 31 L Shiyong 4 Cow-A-Yakeshi n 2 //
□ Words q; H Yukikuni Hita This shows the magnetic head characteristics of a four-layer multilayer film.

In this magnetic head, since the intermediate layer is thick, a stiff gap appears and an abnormality appears in the reproduction output characteristics.

In contrast, the magnetic head of the present invention has curves 32 and 3.
3, showing excellent head characteristics.

For example, the song 'llA32 shows the magnetic head characteristics of a film multilayered into five layers using a 0.05 μm Sin intermediate layer. In this case, it is particularly good at high frequencies. On the other hand, curve 33 shows 1
The magnetic head characteristics of a multilayer film including zero layers are shown. In this case, it was found that the overall reproduction output increased due to the extension of the frequency characteristics.

〔Effect of the invention〕

As explained above, according to the present invention, high saturation magnetic flux density is formed on at least both sides of the protrusions of two protective cores each having a protrusion having a V-shaped cross section on the surface facing the magnetic recording medium. In a magnetic head, a magnetic alloy with high magnetic permeability is deposited on the tip of the protrusion, and the magnetic alloy films face each other across an operating gap at the tip of the protrusion to form a magnetic circuit. The intermediate layer consists of a multilayer film with a thickness of 0.01 μm and 0.2 μm.
By configuring the multilayer film with more than one layer, it is possible to obtain excellent recording and reproducing characteristics for a high coercive force recording medium.

[Brief explanation of the drawing]

Figures 1 (a) and (b) are top and side views of a conventional magnetic head using a composite material, and Figures 2 (,) and (b) are top views of an improved conventional magnetic head. 3 is an enlarged top view of the multi-layered magnetic head using the conventional example shown in FIG. 2, and FIGS. 4(a) and 4(b) are top views and side views showing an example of the magnetic head of the present invention. 5 and 6 are enlarged top views for explaining an example of the multilayer structure of the magnetic head of the present invention, FIG. 7 is a side view showing the structure of another magnetic head of the present invention, and FIG. 9 is a perspective view showing the magnetic alloy portion of FIG. 7, and FIG. 9 is a curve diagram comparing the reproduction output characteristics with respect to frequency of the conventional magnetic head and the magnetic head of the present invention. 20.20'...protection block, 21.21'...
Magnetic alloy, 22.22'...Nonmagnetic filler, 23...
- Operating gap, 24... Window for coil winding, 25.2
5' No. 30 No. 9 Yakuoka gl iron chi (bar Hz) Continuation of page 1 [phase] Inventor Hisashi Morikawa - @ Inventor Takayuki Kobayashi

Claims (1)

[Scope of Claims] (2) High saturation magnetic flux density and high permeability on at least both sides of the protrusions of the two protective cores each having a protrusion with a V-shaped cross section on the surface facing the magnetic recording medium. In a magnetic head in which a magnetic alloy with a magnetic flux is deposited, and the magnetic alloy films face each other across a working gap at the tip of the protrusion to form a magnetic circuit, the magnetic alloy is bonded to the tip of the protrusion through an intermediate layer. Consisting of a multilayer film, the intermediate layer has a thickness of 0.01 μm to 0.1 μm.
A magnetic head characterized in that it is a multilayer film of two or more layers of μm. 2. The magnetic head according to claim 1, wherein the intermediate layer is an electrical insulator. 3. The magnetic head according to claim 1, wherein the intermediate layer is made of a magnetic material. 4. The magnetic head according to claim 1, wherein the magnetic alloy film is an amorphous magnetic alloy. 5. The magnetic head according to claim 1 or 4, wherein the thickness of one layer of the magnetic alloy film is 2 μm to 10 μm. 6. The magnetic head according to claim 1, wherein the protective core is made of ferrite. 7. The magnetic head according to claim 1, wherein the protective core is made of a non-magnetic material.