JPS6159616A - Production of magnetic head core - Google Patents

Abstract

PURPOSE:To obtain a magnetic head core having excellent magnetic characteristics by weighing 'Sendust(R)' materials consisting of Fe, Al and Si having different m.p., and vapor pressures at a prescribed ratio, subjecting the materials to vacuum melting during vapor deposition stage using an electron beam then forming continuously a thick film to the thickness corresponding to the width of a head track in the same vacuum by using electron beam vapor deposition in continuation. CONSTITUTION:A heater and a nonmagnetic substrate 3 are disposed in the upper part in a vacuum bell-jar 1 and a shutter 4 is provided. When an electron bean 6 is irradiated to a tablet 8 consisting of Fe, Al and Si in a crucible 7, the vapor flow of the elements is deposited by evaporation while the shutter 4 is open. The film deposited by evaporation is thus formed. The tablet 8 in the crucible 7 is made into the 5-layered structure in which the essential components Fe 9, Al 10 and Si 11 are respectively formed into a laminar state. The three elements Fe 9, Al 10 and Si 11 are thus uniformly melted.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a method for manufacturing a magnetic head core using vapor deposition technology such as electron beam evaporation. (A[),
The present invention relates to a film forming technology for a core containing silicon (Si) or the like as a main component.

<Prior art> In recent years, in the field of magnetic recording technology, there has been a strong demand for increased recording density as information becomes more diverse.
Therefore, it has become necessary to set the track width and gap length of the magnetic head as small as possible to produce a magnetic head having high magnetic permeability and high saturation magnetization.

In manufacturing the core of a conventional magnetic head, when a bulk member is cut into blocks and a track width of 30 μm or less is formed using a dicing grade, etc., chipping due to impact from the dicing blade or track l? The accuracy of i is a problem. Furthermore, when a ribbon made by an ultra-quenching method such as sendust or amorphous is used as the head core, the core material is sandwiched between nonmagnetic substrates by resin adhesion. With resin adhesives, it is difficult to control the adhesive layer, and the adhesive layer generally tends to be thick.

However, in consideration of the effects of abrasion during sliding, weather resistance, etc., it is necessary to form the adhesive layer thinly. Further, when the trunk width is formed by cutting from a ribbon or a bulk member, controlling the track width becomes more difficult as the track becomes narrower. When the sputtering method is used, the film formation rate is slow and a long process is required.

<Object of the Invention> The present invention involves weighing sendust core materials made of iron, aluminum, and silicon, which have different melting points and vapor pressures, in a predetermined ratio, melting them in vacuum during an electron beam evaporation process, and then continuously depositing them with an electron beam. The purpose of the present invention is to provide a method for manufacturing a magnetic helix core that eliminates the problems of the conventional method by continuously forming a thick film in the same vacuum to a thickness equivalent to the head track width without using vapor deposition. shall be. Another object of the present invention is to produce a head core with high magnetic permeability that contains almost no impurities and can be produced in a short time.

<Embodiment> FIGS. 1A and 1B are schematic configuration diagrams of an electron beam evaporation apparatus for explaining an embodiment of the present invention. Above the vacuum belljar 1 are placed a heater 2 for heating and maintaining the deposition substrate at the deposition temperature, and a non-magnetic substrate made of crystallized glass, ceramic, etc. on which a deposition film is to be formed.

Between the non-magnetic substrate 3 and the evaporation source, there is interposed a filter 4 for controlling the passage of the evaporation air flow. There is a crucible (hearth) 7 arranged in the irradiation direction of the electron beam 6 generated in the FJ.
A tablet 8 made of iron, aluminum, and silicon, which are A-source materials, is placed. When the taglet 8 is irradiated with the electron beam 6, the appropriate element flies off as a vapor flow, passes through the shutter 4 and is deposited on the non-magnetic substrate 3 while the shutter 4 is open, forming a vapor deposited film. is formed.

The tablet 8 placed in the crucible 7 is formed as shown in FIG. 1(B). That is, iron 9, aluminum 10, and silicon 11, which are the main components of the tabletop 8, are each formed into layers, and aluminum 10 is laminated on both sides of the silicon 11 in the center, which is further sandwiched by iron 9 on the outside. It consists of a total of 5 layers.

By configuring the tapelet l-8 in this way, iron 9,
Aluminum 1 has a lower melting point and higher vapor pressure than silicon 11
The phenomenon that 0 evaporates before becoming a solid solution in iron 9 during the melting process described later does not occur, and iron 9, aluminum 10. silicon 1
It becomes possible to uniformly melt the three elements of 1. The composition of tablet 8 is 60-70 wt% iron, 3-6 wt% aluminum, and 20-30 wt% silicon (
11°f and the overall weight is set at 80-110 gr.

The alloy consisting of these three elements is a high magnetic permeability alloy known as Sendust core material, and according to the present invention, a high magnetic permeability core thick film having a Sendust composition or a composition close to this is formed. Filament 5 in electron beam evaporation
9 iron, 10 aluminum, 11 silicon in the process of applying external power to
In order to prevent bumping and maintain a uniform melted state, the tablet 8 is vacuum melted with an electron beam while being maintained at 0.5 to I KW for 14 minutes according to the current flow curve shown in FIG. After that, external pressure is applied for 23 minutes at a rate of 0.1 to 0.5 KW per minute until aKW is reached. As a result, iron 9 in crucible 7
, the molten state of aluminum 1O1 silicon 11 is made uniform. After that, 10KW at a rate of 2-4KW per minute
Pressure increases to After the electron beam power reaches 10 KW, the shutter 4 is kept open for a certain period of time, and the nonmagnetic substrate 3 is taken out to form a deposited film thereon. The obtained vapor-deposited film was divided into 1.3-μm-thick sections corresponding to various holding times from 1 minute 10 seconds to 17 minutes 20 seconds, and changes in film composition were sequentially investigated by chemical analysis. An example of the composition distribution is shown in FIG. Figure 3 shows the holding time after reaching the electron beam power of 10KW: 1 minute 10 seconds to 3 minutes 20 seconds, 3 minutes 20 seconds.
seconds to 5 minutes 50 seconds, 5 minutes 50 seconds to 8 minutes 50 seconds, 8 minutes 50 seconds to 11 minutes 50 seconds, 11 minutes 50 seconds to 14 minutes 20 seconds, and 14 minutes 20 seconds to 17 minutes 20 seconds. Set each area IR,
II, I[l.

The film compositions during film formation in the case of IV, V, and VI are shown. In this way, in electron beam evaporation, due to the different melting points and vapor pressures of each element, a compositional distribution occurs in the film thickness direction during film formation. In this embodiment, the opening and closing of the Nyanta 4 is controlled for this composition distribution, and electron beam evaporation is performed through the electron beam power boosting process shown in FIG. After the electron beam power reached 10 KW, the shutter 4 was opened only from 3 minutes 40 seconds to 15 minutes 40 seconds after the aluminum evaporation rate reached the maximum, and a 5 μm thick Sendust RMT nonmagnetic substrate 3 was deposited. Figure 4 is a perspective view showing the overall appearance of Ruppo 7. Ruppo 7 has a plurality of storage chambers 12 and S for storing tablets 8 shown in Figure 1 (B).
A storage chamber 13 for storing materials for forming an insulating layer such as r 02 and A 11203 is arranged along the circumferential direction. Further, the Ruppo 7 is rotatably supported by a rotating shaft 14. After creating a 5 μm thick sendust film,
The crucible 7 is rotated and the storage chamber 13 is irradiated with an electron beam in the same vacuum to form an insulating film of 5I02 or A620x to a thickness of about 2000 Å on the sendust film. Next, the Ruppo 7 is rotated again to irradiate the storage chamber 12 with an electron beam to deposit a 5 μm thick sendust film on the insulating film. Thereafter, this operation is repeated to alternately stack 5 .mu.m Sendust films and 2000 .lambda. insulating films, each having a thickness of 4.cm. As described above, a high magnetic permeability magnetic head core having a laminate structure with a track width of 20 μm and a width of 20 μm is manufactured. The insulating film is an intermediate layer inserted to prevent effective magnetic permeability from attenuating at high frequencies due to eddy currents.

The film formation rate of sendust film is 2000 to 5000
The film thickness of one layer is approximately 2 to 6 μm. The film composition of the sendust film obtained in this actual color example was determined by chemical analysis: I) Fe 85.7 wt%, Si 9.8
wt% and Ag4.5wt%. This film was heated to 600℃
Electrical specific resistance reduced to 71μ by heat treatment in vacuum for 2 hours.
Ω mouth, holding force 0.50e, saturation magnetic flux density 11.0OOG
A magnetic head having a track width of 20 .mu.m and extremely excellent magnetic properties could be manufactured. The frequency characteristic of effective magnetic permeability of the head core thick film material produced by the method of this example is shown at 41 in FIG. In addition, 42 in the figure is a head core material with a track width of 20 μm having a sendust film thickness of IQpm and an insulating film (SiOz) of 200 OA at 600°C.
・Frequency characteristics of effective magnetic permeability after 10 hours of heat treatment, 7
! 3 is a head core material with a sendust film thickness of 20 μm, an insulating film of 2000 A, and a track width of 20 μm at 600°C.
The frequency characteristics of effective magnetic permeability after heat treatment for 10 hours are shown. According to this example! The obtained magnetic head core is 5M
The effective magnetic permeability of Hz is 1100, and the other 12. g
It can be seen that this head core material is extremely superior in high frequency bands compared to No. 3. Furthermore, if the method of this example is used,
It is also possible to continuously manufacture magnetic head cores having arbitrary track widths of 10 μm, 20 μm, 30 μm, etc. in the same vacuum.

<Effects of the Invention> As explained above in detail, the present invention utilizes an electron beam vacuum melting technology that uses iron, aluminum, and silicon, which are abundant and inexpensive resources, and which produces virtually no impurities in a vacuum. By making full use of electron beam vacuum evaporation technology with a high deposition rate, head core materials with excellent magnetic properties can be manufactured. It is very effective in producing digital audio heads and high-quality VTR heads, which are becoming increasingly popular. Still, the present invention is suitable for mass production, and enables mass production of magnetic head cores having a predetermined track width with excellent effective magnetic permeability in a high frequency band at low cost.

[Brief explanation of drawings]

FIGS. 1A and 1B are schematic configuration diagrams of an electron beam evaporation apparatus for explaining one embodiment of the present invention. FIG. 2 is an explanatory diagram showing a power operation curve in electron beam evaporation. Figure @3 is a composition distribution diagram in the film thickness direction corresponding to the deposition time of the simulated vapor shield film. @Figure 4 is an external perspective view of the vase shown in Figures 1 (A) and (B). FIG. 5 is a characteristic diagram showing the frequency characteristics of the effective magnetic permeability of the magnetic head core obtained according to the present invention. 1...Vacuum bell jar 3...Nonmagnetic substrate 4.
Shutter 5...Filament 1-6...Electron beam 7...Rutsu FY 8=-tablet, year,
Agent Patent attorney Aihiko Fuku (2 people) <A
> Figure 1 Figure 3 Figure 4

Claims (1)

[Claims] 1. A first vapor deposition source material containing iron, aluminum, and silicon as components, and a second vapor deposition source material containing components for forming an insulating film by vapor deposition.
arranging the first evaporation source material in parallel at the evaporation position and melting it with an electron beam, followed by electron beam evaporation to form a head core film; and the second evaporation source material. 1. A method for manufacturing a magnetic head core, characterized in that the steps of arranging a film at a vapor deposition position, performing electron beam vapor deposition, and forming an insulating film superimposed on the head core film are successively carried out in the same vacuum system.