JPH079689B2 - Method for manufacturing Fe-Al-Si film for magnetic head core - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of manufacturing a magnetic head core formed of a magnetic alloy film (sendust alloy film) containing iron, aluminum, and silicon.

<Prior Art> An iron-aluminum-silicon alloy, that is, a sendust alloy is conventionally well known as a material having a high magnetic permeability characteristic and being extremely useful as a material of a magnetic head. As a method for forming the sendust alloy on the magnetic head film, the following (1) to (3) have been conventionally used. (1) A method of processing a bulk material of sendust alloy into a predetermined film thickness by polishing, (2) a method of forming a sendust alloy film with a predetermined film thickness by sputtering, and (3) a sendust alloy film by a liquid quenching method. Is a method of forming. However, the method (1) is extremely difficult to process because the bulk material of the sendust alloy is brittle. The method (2) above is not suitable as a manufacturing method for forming a relatively thick film for a magnetic head or the like, because the film forming speed is very slow. The above method (3) is not preferable because the thickness of the sendust alloy film is limited by the manufacturing conditions. Further, when the produced film is processed, the problems of brittleness and particle size of the sendust alloy film remain.

On the other hand, as a novel method of manufacturing a magnetic head film that solves all of the above-mentioned problems, the present inventors have already proposed that the composition of aluminum is 1 and composed of iron, aluminum and silicon.
~ 6wt% and silicon composition is set to 20 ~ 30wt% Alloy tablet is irradiated with electron beam in vacuum to evaporate the substance evaporated from the alloy tablet on the substrate to form magnetic film of proper composition By further heat treating the magnetic film in the temperature range of 400 ° C to 800 ° C,
A method of manufacturing a magnetic head core for producing a magnetic film of good quality iron-aluminum-silicon has been proposed (Japanese Patent Application No. 58-58).
-11041).

In the magnetic film produced by the above manufacturing method, magnetic characteristics such as magnetic permeability and temperature dependence of magnetic characteristics are variously changed depending on the composition ratio of the sendust alloy.

<Object of the Invention> The present invention provides a magnetic head core having stable characteristics against external factors such as temperature by controlling vapor deposition conditions.
It is an object of the present invention to provide a manufacturing method that can be easily and stably supplied.

<Embodiment> FIG. 1 is a schematic configuration diagram of an embodiment of an electron beam vapor deposition apparatus used in a method of manufacturing a magnetic head core according to the present invention. The inside of the vacuum bell jar 1 is maintained at a high vacuum, and a substrate 2 on which a vapor deposition film is formed and a heater 3 for heating the substrate 2 are arranged above the vacuum bell jar 1. The substrate 2 has a coefficient of thermal expansion similar to that of Sendust alloy (about 100 to 180 × 10 ^-7 deg ^-1 ) Photosensitive glass such as Corning's Photoceram or Hoya Glass's PEG series, non-magnetic ferrite, ceramic or austenite type Stainless steel is used. A hearth (crucible) 4 is placed below the vacuum bell jar 1, and an alloy tablet 5 as a vapor deposition source material is housed in the hearth 4. A filament 6, which is an electron beam generation source, is arranged on the side of the hearth 4, and the electron beam 7 generated by the filament 6 is bent by a magnetic field and is applied to the alloy tablet 5. Hearth 4 and Board 2
A shutter 8 is provided between them, and the vapor flow evaporated from the alloy tablet 5 passes or is blocked according to the opening / closing operation of the shutter 8.

As the alloy tablet 5, a sendust alloy material having a composition of 4 wt% aluminum, 27.5 wt% silicon, and the balance iron was used. In general, it is known that the magnetic permeability of Sendust alloy largely changes depending on the composition ratio, and a sharp peak exists in a specific composition range. Therefore,
Adjusting the composition ratio has an important effect on the magnetic properties of Sendust alloy. The commonly used Sendust alloy has a high magnetic permeability, with aluminum set to 6 wt% and silicon set to 9.5 wt%. However, when an Fe-Al-Si-based film is manufactured by such a vapor deposition method, the vapor pressure differs depending on each element, and therefore the composition changes with the elapse of vapor deposition time. However, the composition of aluminum is 1 to 10 wt% and the composition of silicon is 6 to 12 wt% in the film thickness direction.
%, While comparing the Al composition to 6 wt% and decreasing from the larger value to less than 6 wt% in the film thickness direction and then increasing again, the composition distribution of Si is set to Compared to 9.5 wt%, if the deposition conditions are controlled so that the composition distribution increases from a value smaller than 9.5 wt% in the film thickness direction and gradually exceeds that value, it is possible to protect against the external environment. A stable Fe-Al-Si film having good magnetic properties can be obtained.

This embodiment will be described below in the order of manufacturing steps. Before the vapor deposition process, the temperature of the substrate 2 is set in the range of 100 ° C to 600 ° C. In this example, this was set to 400 ° C. The heating of the substrate 2 is intended to improve the adhesion of the deposited film and is performed by the heater 3. In the vapor deposition process, the electric power supplied to the filament 6 is set to 10 KW, and the electron beam is swept across the entire hearth 4. In order to investigate the composition distribution in the film thickness direction of the vapor deposition film produced based on the above vapor deposition conditions,
From 1 minute 10 seconds to 3 minutes 20 seconds, 3 minutes 20 seconds to 5 minutes 50 seconds, 5 minutes 50 seconds to 8 minutes 50 seconds after the input power reaches 10KW , 8 minutes 50 seconds to 11 minutes 50 seconds later, 11
Minutes 50 seconds to 14 minutes 20 seconds later and 14 minutes 20 seconds to 17 minutes 20 minutes later
The shutter 8 is opened only in each time zone after the second, and the vapor deposition film is individually formed. The obtained vapor-deposited films are sequentially used as samples I, II, III, IV, V, and VI, and their magnetic properties and chemical analysis sites are determined.

The values shown in the above table are the values after using a photosensitive crystallized glass as the substrate 2 and performing heat treatment at a temperature of 600 ° C. in a vacuum for 4 hours, and the magnetic permeability μ ′ is a value at 1 MHz. is there.

From the above experimental results, it is found that the vapor-deposited film obtained by opening the shutter 8 from the time when the input power reaches 10 KW to 3 minutes and 20 seconds to 14 minutes and 20 seconds exhibits good characteristics. . For example, the magnetic characteristics of the film obtained by opening the shutter 8 after 3 minutes and 40 seconds and closing the shutter after 15 minutes and 40 seconds after the applied power reached 10 KW were as follows. The magnetic properties of the obtained film after heat treatment in vacuum at 600 ° C for 4 hours are as follows: saturation magnetic flux density Bs = 11400G, electric resistance ρ = 72μΩcm,
Coercive force Hc = 0.6e, permeability μ ′ (1MHz) = 2800, μ ′ (10
MHz) = 1400. The result of chemical analysis is 4.5 wt%
It was Al-9.8 wt% Si-85.7 wt% Fe. FIG. 2 shows the temperature dependence of the magnetic flux density B of this vapor deposition film. The horizontal axis represents temperature, and the vertical axis represents magnetic flux density B induced by the external magnetic field Hex = 0.114e. Since the magnetic permeability μ has a relationship of B = μ′H, the temperature change of μ is also the same. When the temperature dependence of the magnetic permeability μ is examined for various film compositions, the film having a composition around 4.5 wt% Al-10.595% Si-85 wt% Fe has the highest magnetic permeability μ at room temperature. Al3-6wt as film composition
In the range of% -Si8 to 12 wt% -remaining Fe, for example, the temperature at which μ has the maximum value is −100 ° C. or more at −70 ° C. or higher, and at room temperature, μ is more than half of the maximum value. Therefore, it is possible to secure stable characteristics that are not easily influenced by external factors, that is, temperature. However, regarding the composition distribution in the film thickness direction at this time, as described above, Al1 to 1
This is the case of 0 wt% -Si6 to 12 wt% -the balance Fe. FIG. 3 shows the results of investigations on magnetostriction, which is considered to have a great influence on the soft magnetic film.

However, these alloy films are also those in which the composition distribution in the film thickness direction is within the aforementioned composition range. The shaded area in the figure
This is the portion of magnetostriction λsO.

In the range of the film composition, that is, Al3 to 6 wt% -Si8 to 12 wt% -the balance of Fe is not largely deviated from this shaded portion, and from the viewpoint of magnetostriction, the composition range is due to external stress. It turned out that it was hard to be affected.

<Effect> As described in detail above, according to the magnetic head core manufacturing method of the present invention, the sendust alloy film is formed by the vapor deposition method, so that a very high film forming rate of 0.1 to 1 μm / min is achieved. Therefore, there is an advantage that a thick soft magnetic film used as a core of the magnetic head can be easily formed in a short time, and a batch process can be performed by a vapor deposition process or a dry process.

Further, according to the method of manufacturing a magnetic head core according to the present invention, the composition of the Fe-Al-Si film by controlling the vapor deposition conditions, in the film thickness direction, Al: 1-10 wt%, Si: 6-12 wt% The composition distribution is such that the Al composition is changed to fall within the range, the Al composition is compared to 6 wt%, and the composition distribution increases from the value higher than that to less than 6 wt% in the film thickness direction and then increases again.
Of the composition of 9.5 wt% compared to 9.5 wt%, the vapor deposition conditions are controlled so that the composition distribution increases from the value smaller than 9.5 wt% in the film thickness direction and gradually exceeds the value. It is possible to easily manufacture a magnetic head core that is not easily affected and has very good magnetic characteristics. Specifically, it is possible to obtain a very good magnetic head core having a large magnetic permeability and a small coercive force. Further, in the manufacturing method of the present invention, as described above, a large value of the magnetic permeability which largely depends on the magnetic head efficiency is obtained. Since it is possible to manufacture a magnetic head core having the above, it is extremely useful as a method for manufacturing a magnetic head core for high-density magnetic recording and reproduction.

[Brief description of drawings]

FIG. 1 is a configuration explanatory view of an electron beam vapor deposition apparatus used for explaining one embodiment of the present invention. FIG. 2 is an explanatory diagram showing the temperature dependence of magnetic permeability. FIG. 3 is an explanatory diagram showing the composition distribution of magnetostriction. 1 ... Vacuum bell jar, 2 ... Substrate, 3 ... Heater,
4 ... Hearth, 5 ... Alloy tablet, 6 ... Filament, 8 ... Shutter.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuhei Tsuchimoto 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Inventor ▲ Mitsuhiko Yoshikawa 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka No. 22 Within Sharp Corporation (56) Reference JP-A-59-136415 (JP, A) JP-A-59-121629 (JP, A) JP-B-51-44644 (JP, B2)

Claims (1)

[Claims] 1. A method of manufacturing a magnetic head core composed of an Fe-Al-Si film, comprising heating an alloy tablet composed of iron Fe, aluminum Al and silicon Si, and evaporating from the alloy tablet by the heating. A material is deposited on a substrate, and the composition distribution of the Fe-Al-Si film is Al: 1-10wt%, Si: 6-
The composition distribution is changed in the film thickness direction in the range of 12 wt%, and compared with the composition of Al to 6 wt%, the composition distribution is such that it decreases from the larger value to less than 6 wt% in the film thickness direction and then increases again. , Si composition compared to 9.5 wt%, so that the composition distribution increases from a value smaller than 9.5 wt% in the film thickness direction and gradually exceeds the value, into the alloy tablet evaporation means of the vapor deposition device. Fe-Al for a magnetic head core characterized by obtaining a Fe-Al-Si film having magnetic characteristics that is not easily affected by temperature changes by vapor deposition with a vapor flow in a desired time period after the electric power reaches a certain value. -Si film manufacturing method.