JPH0584566B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to a method of manufacturing a magnetic head core formed using a vapor deposition technique such as electron beam vapor deposition.

<Prior Art> In recent years, in the field of magnetic recording technology, there has been an increasing demand for increased recording density due to the diversification of information. One way to increase the density of magnetic recording is to increase the coercive force of a recording medium, and in order to cope with this, it has become necessary to develop magnetic head core materials having high saturation magnetic flux density and high magnetic permeability. As such a material, since ferrite has a limit in saturation magnetic flux density, an alloy-based material is suitable. As is well known, Sendust alloy contains 9.5wt% Si.
In a composition centered on Al5.5wt% and the balance Fe,
Although it is a material with high magnetic permeability and high saturation magnetic flux density, it is difficult to precisely process bulk sender dust when making magnetic head cores because it is brittle, and a core thickness of about 20 μm is required when applied to VTRs, etc. In that case, there are drawbacks such as insufficient high frequency characteristics. In addition, when using Sendanst ribbon made by ultra-quenching method as a head core,
The core material is sandwiched between nonmagnetic substrates by resin adhesion, but it is difficult to control the adhesive layer with resin adhesion.
Furthermore, when the track width is formed by cutting from a bulk member or ribbon, control of the track width becomes more difficult as the track becomes narrower. For this reason, a method has been proposed in which a narrow track magnetic head is fabricated by sputtering or vapor deposition a Sendust thin film having excellent high frequency characteristics and corresponding to the track width on the surface of a nonmagnetic substrate.

<Object of the invention> The present invention provides a magnetic head core with good workability by changing the base substrate temperature during the formation of a soft magnetic film by evaporation using an electron beam evaporation method or the like to obtain a crystal structure with good magnetic properties. With the goal.

<Example> FIG. 1 is a schematic diagram of an electron beam evaporation apparatus for explaining an example of the present invention.

Above the vacuum bellgear 1 are a heater 2 for heating and maintaining the deposition substrate at the deposition temperature, and a non-magnetic substrate 3 made of crystallized glass, ceramic, photosensitive crystallized glass, glass, etc. on which the deposition film is formed. is located. A shutter 4 is interposed between the nonmagnetic substrate 3 and the evaporation source to control the passage of the evaporation air flow. Further, at the lower evaporation source position, there is a filament 5 for generating an electron beam and a crucible (hearth) 7 arranged in the irradiation direction of the electron beam 6 generated by the filament 5.
%, aluminum in a proportion of 3 to 6 wt %, and silicon in a proportion of 20 to 30 wt %.
When the electron beam 6 is irradiated onto the evaporation source material 8, the elements in that area become a vapor flow and fly away, causing the shutter 4
The non-magnetic substrate 3 passes through the shutter 4 during the opening period.
A vapor deposited film is formed.

Here, in order to investigate the influence of the difference in base substrate temperature during the formation of a soft magnetic film by electron beam evaporation on the characteristics of the soft magnetic film formed thereon, we used the above-mentioned evaporation source material and heated it to 100 to 400°C. The temperature of the nonmagnetic substrate was varied within the range of
A Si-Al based soft magnetic film was formed. The film composition was determined by energy dispersive analysis using a scanning electron microscope and was found to be 86.0 wt% Fe, 9.5 wt% Si, and 4.5 wt% Al. After heat-treating this film at 600℃ for 6 hours in vacuum, the effective magnetic permeability μ' at 1MHz, the coercive force Hc,
The saturation magnetic flux density Bs and electrical resistivity ρ were measured and the relationship with the substrate temperature was investigated. The results are shown in FIG. Also, judging from the change in stress in the magnetization curve, magnetostriction λs
was correct. The Fe-Si-Al soft magnetic film formed on the surface of a non-magnetic substrate at a substrate temperature of 200°C to 350°C is
Effective magnetic permeability at 1MHz is over 1800, coercive force is under 1Oe,
Saturation magnetic flux density 11500G or more, electrical resistivity 70μΩcm,
It was found to have excellent magnetic properties and wear resistance, with a Vickers hardness of 600. Among them, Fe formed on the surface of a nonmagnetic substrate at a substrate temperature of 300°C.
-Si-Al based soft magnetic film has an effective magnetic permeability of 1MHz.
3800, coercive force 0.6 Oe, and saturation magnetic flux density 12000 G. It had very excellent magnetic properties.
In addition, in the case of a Fe-Si-Al soft magnetic film formed on the surface of a non-magnetic substrate at a substrate temperature of 100° C. or less, the magnetic film had poor adhesion to the substrate and peeled off. Next, FIG. 3 shows the dependence of the crystal structure on the substrate temperature by X-ray diffraction. On the high side of the substrate temperature, the magnetic film became (100) oriented and its magnetic properties decreased, and the peak intensity at the (022) plane at a substrate temperature of 300°C was strongest and the magnetic properties were the best.

<Effects of the Invention> As explained in detail above, when creating a Fe-Si-Al soft magnetic film by electron beam evaporation, by selecting the substrate temperature between 200 and 350°C, a soft magnetic film with good magnetic properties can be obtained. A magnetic film is formed, and the magnetic permeability of the core can be improved, thereby making it possible to improve the efficiency of the magnetic head.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of an electron beam evaporation apparatus used to explain one embodiment of the present invention, and Fig. 2 shows a Fe-Si-Al system fabricated by electron beam evaporation on the surface of a non-magnetic substrate with different substrate temperatures. Figure 3 shows the relationship between the effective magnetic permeability, coercive force, saturation magnetic flux density, and electrical resistivity of soft magnetic films at 1MHz.
FIG. 2 is a relationship diagram of the crystal structure of a -Si—Al based soft magnetic film obtained by X-ray diffraction. In the figure, 1...vacuum bellgear, 2...heater, 3
... Nonmagnetic substrate, 4 ... Shutter, 5 ... Filament, 6 ... Electron beam, 7 ... Crucible (hearth), 8 ... Evaporation source material.

Claims (1)

[Claims] 1. To form a soft magnetic film on a non-magnetic substrate,
A method for manufacturing a magnetic head core, characterized in that a Fe-Si-Al based soft magnetic film is formed by electron beam evaporation under the condition that the surface temperature of the non-magnetic substrate is 200°C to 350°C. 2. The evaporation source material of the soft magnetic film is 60 to 70 wt% iron,
2. The method of manufacturing a magnetic head core according to claim 1, wherein the magnetic head core is comprised of 3 to 6 wt% of aluminum and 20 to 30 wt% of silicon.