JPS61230607A - Magnetic head core - Google Patents

Abstract

PURPOSE:To improve the soft magnetic characteristic of a laminate of multilayered films and simultaneously to prevent a decrease in effective permeability in the high-frequency region by providing >=2 layers of insulating substance thin films having different thicknesses in the laminate of multilayered films. CONSTITUTION:A soft magnetic thin film 7 having <=2mum thickness and an insulating substance thin film 8 having <=0.05mum thickness are alternately deposited to form a laminate of from several to several tens layers of films. An insulating substance thin film 9 having 0.2-0.3mum thickness sufficient for completely insulating between magnetic thin films is deposited on the laminate. The multilayered laminate 10 is further laminated and deposited thereon in from several to several tens layers. A laminate of multilayered films having specified film thickness is obtained by repeating the process. A magnetic head core element is cut out from the laminate of multilayered films and a couple of elements are bonded to obtain a magnetic head core having high effective permeability in the high-frequency region.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic field, and in particular, to a multilayer film laminate in which soft magnetic alloy thin films and insulating material thin films are alternately deposited and laminated. The present invention relates to the structure of a multilayer film V4N body suitable for improving the magnetic properties in the high frequency region of a magnetic helder using a magnetic helder.

[Conventional technology] Conventional magnetic helad cores are mainly made of ferrite 1, sintered bodies,
Alternatively, it can be formed by joining WJ) cut from a single crystal.Recently, amorphous alloys made of various combinations of transition metals and vitrified metals have been found to be suitable for soft magnetic properties. This has attracted attention, and magnetic head cores made of laminated ribbons of amorphous magnetic alloy are now commercially available.

Further, as a method for manufacturing an amorphous alloy magnetic head core, an amorphous alloy is obtained in the form of a thin film, and this is sandwiched between ten non-magnetic plates prepared separately in advance to form a laminate. Either process this into a core shape and manufacture a magnetic head by a known method, or place an amorphous magnetic alloy on a non-magnetic substrate.
A magnetic head core is manufactured by a known method using a multilayer film laminate obtained by depositing thin films of an insulating material such as i02 or spinel alternately to form #1 layer using a method such as sputtering. C (Japanese Unexamined Patent Publication No. 59-1177)
29). These methods aim to improve the soft magnetic properties (particularly in the high frequency region) of a multilayer film stack by laminating a magnetic base metal thin film via a thin film of an insulating material. , all of them use a multilayer film laminate obtained by alternately laminating a magnetic alloy with a film thickness of 4T and an insulating material with a uniform film thickness.In this case, between the magnetic alloy thin films, The soft magnetic properties of the multilayer film stack will improve as the thickness of the thin film of the insulating material stacked on the multilayer film stack improves.
This has the drawback that eddy current loss increases in the high frequency region (MHz region), making it difficult to achieve the desired objective in preventing a decrease in effective magnetic permeability. However, if the layered insulating material is thick, the soft magnetic properties of the multilayer film stack cannot be improved. However, none of them disclose anything about changing the film thickness of this insulating material.

[Problems that Kagomei tries to solve] The thickness of the insulating material sacrificially laminated between the magnetic thin films by the conventional method improves the soft magnetic properties of the multilayer film stack, but it is difficult to partially insulate the film. is insufficient, resulting in an increase in eddy current loss, making it difficult to achieve the desired objective of preventing a decrease in effective magnetic permeability in a high frequency region (MHz region). However, if the thickness of the laminated insulating material is too thick, there is a drawback that the soft magnetic properties of the multilayer film@pathological body cannot be improved.

The object of the present invention is to solve these problems and provide a magnetic rad core with less reduction in effective magnetic permeability in a high frequency region.

[Means for solving the problem] Regarding the structure of the multilayer film laminate in the magnetic herad core of this company, it is necessary to use an insulating material such as a soft magnetic thin film with a thickness sufficient to improve the soft magnetic properties of the soft magnetic thin film. Thin films of the substance are deposited alternately to completely insulate the area where a multilayer film stack of several to tens of layers is formed and the upper and lower stacked magnetic thin films, thereby preventing an increase in eddy current loss. A multilayer film laminate having a predetermined film thickness is formed by combining and laminating one or several thin films of an insulating material having a sufficient film thickness.

In this application, the deposited soft magnetic alloy may be a crystalline alloy or an amorphous alloy. Furthermore, since the magnetic alloy is used in a high frequency range, it is advantageous for the film thickness to be several microns or less in order to reduce eddy current loss and prevent a decrease in effective magnetic permeability in the high frequency range. In this case, the thickness of the magnetic alloy is 2 μm or less, preferably around 1 μm. The thickness of the insulating material to improve the soft magnetic properties of the laminated magnetic thin film is less than 0.05 μm, preferably around 0.02 μm. The main feature of the present invention is that insulating thin films of different thicknesses are provided in the multilayer film stack. In other words, soft magnetic thin films and insulating thin films of the above thickness are alternately deposited to form a multilayer film stack of several to several tens of layers, and the film is also thick enough to completely insulate between the magnetic thin films. depositing a thin film of insulating material. It is sufficient that the film thickness of the insulating material is 082 to 03 μm. After depositing this insulating material film, several to several dozen layers of the multilayer film stack of the method for improving the soft magnetic properties described above are further deposited. Moreover, a layer of an insulating material thin film having a film thickness of 0.2 to 0.3 μm is laminated thereon. By repeating these operations, a multilayer lN! of a predetermined film thickness is formed. Obtain a laminate. This 0.2~
For a thin film of an insulating material with a thickness of 0.3 μm, it is sufficient to laminate one layer every few or ten layers in a laminate.
When the thickness of the soft magnetic thin film is 0.3 μm or less, a - layer may be laminated every time the total thickness of the laminated films becomes 1 to 2 μm. The total number of these thin films of soft magnetic alloy and insulating material is determined according to the track width of the magnetic head, and V
For the TR head, the thickness should be 30 to 60 μm.

In this case, the number of thin films of insulating material with a thickness of 0.2 to 0.3 μm is 1
There will be 5 to 30 layers.

Magnetic RAD core elements as shown in FIG. 4 are cut out from the multilayer laminate thus obtained, and a pair are joined to form a magnetic head core as shown in FIG. 5.

[Example] Using the sputtering apparatus shown in FIG. 2, a multilayer film laminate as shown in FIG. 1 was deposited and formed by sputtering. C08 on the surface of the glass substrate 40 having a sufficiently smooth surface.
7Z "A thin film 7-1 of an amorphous alloy having a composition of 5Nb8
It was deposited to a thickness of 1.0 μm. The sputtering conditions were an input power of 500 W and a gas pressure of 3 x 10-3 Torr. Next, using the same equipment, an insulating material was sputtered, and a 0.000. SiO2 insulator 8- with a film thickness of 015μ711
1 was formed. By repeating this operation alternately, three layers of amorphous alloy thin film (7-1, 7-2, 7-3) and two layers of Si02 insulator (8-1, 8-2) were laminated ( ”,
A single layer of SiO2 insulator 9 with a thickness of 0.2 μm was deposited.

In this way, a unit laminate 10-1 of an amorphous alloy thin film and an insulator was produced. On top of this, three more amorphous alloy thin films are applied.
The i! A 2 μm thick SiO2 insulating film was deposited to form a unit laminate 10-2. Repeat this operation and stack the units @carcasses in 8 layers,
Finally, 24 layers of amorphous alloy thin film, film thickness 0.015μH
16 layers of SiO2 insulating film, 0.2 μm thick SiO2
A multilayer film laminate 11 having nine insulating films was obtained. A magnetic radiator of a predetermined size was cut out from this multilayer film laminate 11 by ultrasonic machining, and heat treated at 390° C. for 1 hour in a rotating magnetic field to remove magnetic anisotropy. A comparative example of the magnetic properties of the magnetic herad core thus obtained was obtained by laminating 24 layers of amorphous alloy thin film of the same composition with a film thickness of 1.0/17n and 23 layers of SiO2 insulating film with a film thickness of o, oi 5 μm. A comparison with the magnetic head core shown in FIG. 3 shows that the effective magnetic permeability is clearly high in the high frequency range.

According to the present invention, the thickness of the insulating thin film in the multilayer film stack can be changed depending on the purpose, thereby improving the soft magnetic properties of the multilayer film stack and at the same time improving the soft magnetic properties of the multilayer film stack. This has the effect of preventing a decrease in effective magnetic permeability in a high frequency range, and is extremely useful as a magnetic head core used in a high frequency range.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a cross-sectional view of a multilayer film stack. FIG. 2 shows a conceptual diagram of the sputtering apparatus. FIG. 3 is a graph showing effective magnetic permeability-frequency characteristics, in which (A) corresponds to the example and (B) corresponds to the comparative example. FIGS. 4 and 5 are perspective views of the magnetic herad core.

Claims (1)

[Claims] 1. Thin films of soft magnetic alloy and insulating material are alternately deposited on a non-magnetic substrate to form a multilayer film stack, a pair of core shapes are formed from the multilayer film stack, and a gap is formed between the core shapes. What is claimed is: 1. A magnetic head core manufactured by bonding through a multilayer film laminate, the magnetic head core having at least two layers of insulating thin films having different thicknesses in a multilayer film laminate.