JPS59117729A - Production of magnetic head core - Google Patents

Abstract

PURPOSE:To obtain a head having a secure laminate construction, small size and high performance by depositing alternately thin layers of an amorphous magnetic alloy and an insulating material on a non-magnetic substrate by a sputtering method, etc. to form a multi-layered laminate, forming such laminate into a pair of core shapes and joining the cores via a gap. CONSTITUTION:Amorphous alloy layers 8 having the compsn. satisfying the condition expressed by the formula (T and M consists essentially of Co wherein a part of Co is substd. by >=1 kind of Fe or Ni within 10%, MI is >=1 kind among Zr, Hf and Y, MII is >=1 kind among Nb, Ta, Mo, W and 0.05<=x<=0.2 and MII/ (MI+MII)=0.3-0.9), and SiO2 insulating films 9 are sputtered alternately on a glass substrate 4, whereby a multi-layered laminate 12 is obtd. A semi-annular core half 14 is cut from said laminate by ultrasonic working, etc. and is heat treated in a revolving magnetic field to remove magnetic anisotropy. A pair of the half bodies 14 are joined by an Ag-Cu alloy spacer 12 after a gap surface 14a and a back gap surface 14b and an SiO2 film 11 are formed thereon. A glass protective film 10 is joined thereto and a head 16 is perfected.

Description

[Detailed Description of the Invention] This invention I-1' relates to a method for manufacturing a magnetic helad core, and more specifically, it relates to a method for manufacturing a magnetic head core that uses entirely an amorphous alloy to improve the high frequency characteristics. .

Conventionally, magnetic cores have been mainly formed by laminating and bonding thin pieces cut out from ferrite sintered bodies. In recent years, amorphous magnetic alloys made of various combinations of transition metals and vitrifying elements have attracted attention as soft magnetic materials, and research on the subject is being actively conducted. Amorphous magnetic alloys have come to be used instead of conventional ferrite and the like as magnetic head cores, and magnetic head cores made of laminated ribbons of amorphous magnetic alloys are now commercially available. Conventional amorphous alloy magnetic helical cores were mainly intended for use in transformers or audio equipment, and were operated at relatively low frequencies. On the other hand, the demand for magnetic heads for high-density magnetic recording and reproduction is increasing, and the cost of magnetic helad cores in the high frequency range of megahertz for video tapes is increasing. However, since conventional amorphous magnetic alloys were in the form of ribbons, even if the ribbons were further processed into thin pieces, the thickness would be only 10 μm.
The economical limit is a thin # of about 1.5 m, and there is a drawback that eddy current loss is large in the high frequency range.

Furthermore, the conventional method of manufacturing an amorphous alloy magnetic helad core has many problems, such as deterioration of magnetic properties in a high frequency range. In other words, in the conventional method, the amorphous alloy base material is rapidly cooled and bound into a ribbon, then processed into a magnetic composite/docore shape, and then
After processing it into a thin piece with a thickness of ~50 μm by lapping, etc., the magnetic herad core is completed through various processes such as lamination bonding, forming the gap insulation part of the core, and bonding the core pieces. In this method, there is a limit to the high frequency characteristics due to the thinning caused by polishing such as lapping, and due to processing accuracy, variations in thickness and surface roughness of individual thin pieces occur.
This affected the characteristics of the head core. Moreover, due to variations in force-machining the thin ribbon into the core shape, the dimensions of the inner and outer circumferential surfaces of the core become uneven between laminated thin pieces, which affects the characteristics of the magnetic helad core. Furthermore, since the above-mentioned steps are complicated as a whole, the manufacturing efficiency of the magnetic head core has been reduced.

Furthermore, as a manufacturing method of an amorphous alloy magnetic held core, an amorphous alloy is obtained in the form of a thin film, and a laminate is formed by sandwiching this between a non-magnetic block prepared separately in advance.
- It is also known to process the core into a magnetic rad core through the following steps of insulating the gear part and joining.

However, in this method, the amorphous alloy thin film is formed in the shape of a non-magnetic block as a base, and this i,=4 is bonded as described above to form a multilayer body. I can only apologize. In this case, there is a problem that the magnetization strength of the core is weak and the characteristics are inferior. Furthermore, the current herad core processing method has the drawback that it is difficult to prevent the occurrence of Barkhausen noise and deterioration of frequency characteristics due to domain wall motion.

In view of the above-mentioned state of the art, the present invention has excellent magnetic properties in the high frequency range, has little reduction in effective magnetic permeability especially in the MHz range, and prevents deterioration of magnetic properties due to processing steps. The purpose of the present invention is to provide a method for manufacturing a magnetic herad core.

In the present invention, thin films of an amorphous alloy and an insulating material are alternately deposited on a non-magnetic substrate to form a multilayer film stack.

A method for manufacturing a magnetic helad core, which is characterized by joining via a knob. The present invention will be explained in detail below. In the present invention, since the core laminate is formed by alternately depositing thin films of an amorphous alloy and an insulating material, the core laminate is significantly improved compared to the conventional method of laminating amorphous alloy ribbons. It becomes possible to make it thinner. In this case, the film thickness of the amorphous alloy is preferably 2 μm or less, preferably 1 μm.The total number of thin films of the pre-material is determined depending on the track width of the magnetic head.
It is 0 to - at 8 μm. Since the amorphous magnetic alloy of the present invention is used in the high frequency λ region, a thin film with a thickness of several microns or less is used in order to reduce eddy current loss and prevent a decrease in effective magnetic permeability (μe) in the high frequency region. is advantageous. but,
As the thickness of the material decreases, the strength of magnetization decreases, so it is necessary to compensate for this by creating a multilayer structure. Next, as a deposition method, vacuum evaporation, ion beam evaporation, ion platen knob, and sputtering are considered, but they are applicable to a wide range of compositions and have excellent adhesion between thin films. In this respect, both thin films are preferably formed by sputtering.

There are no particular restrictions on the substrate as long as it is non-magnetic, but glass, ceramics, heat-resistant resins such as polyimide films, reactivity with amorphous alloy films, mN property, thermal expansion coefficient, etc. It is preferable to have a laminated structure with a maximum of 1. The thickness of the substrate is also not particularly limited, but is preferably from 0.05 to 0.02 mm from the viewpoint of small core dimensions and convenience in processing.

Next, in the present invention, the substrate is shaped in advance into a semicircular 'J' shape.
ft is formed in the shape of a pair of horseshoe-shaped helad cores, and an amorphous alloy thin film and an insulating material thin film are alternately deposited on the core-shaped substrate to obtain a multilayer film laminate having a core shape at the same time as the deposition. Alternatively, a thin film of an amorphous alloy and a thin film of an insulating material are alternately deposited on a substrate in advance to form a multilayer film laminate, and then cut into a pair of helad cores. As a result, a multilayer film laminate having a core shape can be obtained.

In the former case, since a core half-shaped object cannot be obtained at the same time as the deposition, there is no problem of magnetic deterioration due to processing stress.

One processing method is diamond cutter, ultrasonic processing, laser processing, and punching. High productivity can be achieved in the punching process when the insulating substrate is an imide film.

Generally, each core half has a symmetrical shape, and the core gap that contacts the magnetic recording medium between the pair of abutted ends resulting from the abutment has a 5in2. Spinel (N?203・Mg0
) and other known insulating materials are placed and filled by sputtering or the like, and the gap on the opposite side of the near gap is filled with a known insulating material such as Cu-
By inserting a conductive material spacer such as Ag,
Each core half piece is joined through these gaps to form a predetermined magnetic path.

If necessary, after annealing is performed before or after joining the core halves, a non-magnetic material having the same shape and preferably the same quality as the substrate is bonded to the upper surface as a dummy substrate to increase the stability of the near shape. I can do it.

In this case, the dummy substrate may be formed into a perforated disk in advance and bonded to the upper surface of the laminate using Epoquin resin or the like.

According to the present invention, the usable range of high frequency characteristics is expanded from the current 10 MHz or less to 500 Ml (zE), high density recording is achieved, and the magnetic herad core is made smaller and lighter.

Amorphous alloys can be conventionally liquid quenched and sputtered. An example composition is 1ce-C.

-8i-B series transition metal toroidal alloys exhibit particularly excellent high frequency characteristics.

An amorphous alloy having a preferable composition will be explained below. This alloy has the compositional formula (T -M) + -x (Mr, Mn
) is represented by x. In this composition formula.

'1''-M is Co ((a ferromagnetic metal whose main component is
C.

It contains more than 90a of rattan. The glaze may be replaced with one or more metals among Co f , Fe, and Ni as long as the magnetism is not impaired. The limit of possible replacement is to use at least one peg out of 1°.

Mrl is an element that makes magnetostriction a negative component, V~b, Ta
, MOLW is used. Mr and Mu] ratio (,1 general K M11/([4N-MII
) = 0.3 to 0.98 degrees is good. On the left, for example, Co and Nb
, when all Ta is added, the magnetostriction (in-, ) is negative as shown in i/i-FIG.

The ratio of Ml and Mu can be selected taking into account the magnetic properties such as saturation magnetization, magnetostriction, and anisotropic magnetic field. The anisotropic magnetic field (Hk) −i is shown. In FIG. 2, the magnetostriction is almost zero near Nb/(Zr+Nb) -0.65, and the anisotropic magnetic field also becomes small.

The thus obtained t1 female amorphous alloy is easily made amorphous, has high saturation magnetization characteristics, has zero magnetostriction, and has small induced magnetic anisotropy. This reduces the decrease in magnetic permeability of RU when left at high temperatures, making it possible to significantly improve thermal stability. For example, the third
The figure shows the decrease in magnetic permeability when thin films of Co-Zr and C)oB7ZrsNb8 are left at high temperatures.
Co--Zr'r: has a low magnetic permeability.Furthermore, according to the present invention, the MI material can be made of the alloy component (2).

The production of thin films of amorphous alloys by the spuck method is T-Mr.
-x (ME, Mn) It is possible even if the amount of the X component is small in the x composition.Therefore, it has the advantage that it is possible to contain a correspondingly large amount of the TM component.

Next, an example will be given and explained.

Example 1 A multilayer film stack was deposited by sputtering using the sputtering apparatus shown in FIG. 4 to form a multilayer film stack. The illustrated substrates, 5 and 6, are DC or AC power supplies.

Glass substrate 4 with a sufficiently smooth surface (dimensions 50H (g
B x 50m + n x 0.1 mm) on the surface,
An amorphous alloy 2 having a composition of C087ZI°5N1)8 was deposited as a thin film 8 (FIG. 5) on a glass substrate 4 to a thickness of 10 μm. The sputtering conditions were: input power of 500 W, Ar gas pressure of 3×10-” Torr, and film thickness formation rate of 05 μtn/”.

Next, the insulating material 3 was sputtered using the same equipment, and an insulator 9 of 0.015 μm thick was formed on the amorphous alloy thin film 8 (FIG. 5) by high-frequency sputtering. . This operation was repeated alternately to obtain a multilayer film laminate 12 having 15 amorphous alloy thin film layers and 14 insulating thin film layers.

Next, a semi-annular core half 14 (FIG. 6) of a predetermined size is cut out from the multilayer film laminate by ultrasonic processing, and this core half is heat-treated in a rotating magnetic field at 370° C. for 30 minutes to obtain magnetic anisotropy. Removed gender.

When the magnetic properties of this core half body 14 were measured, the following results were obtained.

Coercive force HC"" 0.020e Saturation magnetic flux density 1fBS = 11,0OOG Initial magnetic permeability μi = 20,000 Effective magnetic permeability (IOMI-1z) μe f f = 2
The i''Ifr core thus obtained has a high effective magnetic permeability and excellent magnetic properties, particularly in the high frequency range of MHz or higher.

Next, a pair of core halves 14 are prepared, and the gap surface 14a and the pack gap surface 14b are smoothed by lapping process, and then the gap surface 14a is coated with a high frequency sputtering method to give a thickness of 0.3% (S1←) After forming the 2-layer film (FIG. 8), the pair of core halves 14 are made to face each other, and the back gap gB 14b is bonded with an Ag-Cu alloy spacer 12. 1mm thick glass retaining plate 10I Glue with adhesive and attach magnetic head core 16
I got it.

The thus obtained magnetic herad core having a multilayer film structure has ambiguous magnetic properties (particularly effective magnetic permeability 1te ff ) in a high frequency region (Ml-1, z region). Since the production process for cutting can be extremely simplified compared to the conventional method, it is not only economical but also has little deterioration in magnetic properties.

In particular, when a □□□-ZrJ fluoro-based magnetic material is used, the magnetostriction constant (input S) becomes zero and the magnetic anisotropy decreases, so that excellent f-characteristics can be obtained as a magnetic head. Furthermore, the magnetic properties hardly deteriorate during use or storage, and the zero magnetostriction properties are stably maintained despite some fluctuations in the composition.
The performance required for magnetic heads such as these is achieved at a high level.

[Brief explanation of the drawing]

Figure 1 shows Co-NL+, Co-Ta alloy (D magnetostrictive 'f
: Show f graph, Fig. 2 1d Co 87 (Zr, N
b WR graph showing magnetostriction and anisotropic magnetic field, Figure 3 is a graph showing changes in magnetic permeability due to heat treatment, Figure 4 is a conceptual diagram of the sputtering equipment, Figure 5 is a cross-sectional view of the multilayer film stack, 6
The figure is a perspective view of a half-core core, FIG. 7 is a cross-sectional view of a multilayer film laminate with a glass protection substrate bonded to it, and FIG. 8 is a perspective view of a magnetic head core according to Example 1 in which the half-core core of FIG. 6 is bonded. It is a diagram. □ 1... Vacuum chamber, 2... Amorphous alloy, 3... Insulating material, 4... Substrate, 8... Amorphous alloy thin film, 9
...Insulator 10...Glass protection substrate, 14-...Core half-closed, ]6 Magnetic Herad Core Patent Applicant Showa Denko Co., Ltd. 10" (岨m) 7 horses, 6 children

Claims (1)

[Claims] 1. Thin films of an amorphous alloy and an insulating material are alternately deposited on a non-magnetic substrate to form a multilayer film stack, and the multilayer film stack is formed into a pair of core shapes at the same time or after the deposition. A method for manufacturing a magnetic helad core, characterized in that the pair of core-shaped bodies are connected by a full gear valve. 2 The amorphous alloy has the composition formula (1゛・fVl), ,,x(
Ml, MTI)
MT is composed of at least one metal element among ZrJff and Y, and rvln is composed of at least one metal element among Mo and W to P. 0.05 ≦X ≦0.2ihYMn/(MI
-I-Mn)-0.3 to 0.9 ff1ff+a is added to the method of manufacturing a magnetic head core according to claim 1. 3. Claim 1, characterized in that the method of depositing the thin film of the amorphous alloy and the insulating material is by the Spunter method.
A method for manufacturing a magnetic herad core as described in .