JPH0646446B2 - Member for magnetic head core - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a magnetic head core member incorporating a soft magnetic metal thin film made of Fe—Si—Al.

<Prior Art> The recent improvement in recording density in the field of magnetic recording technology has led to a narrower track for a magnetic head as an electromagnetic transducer, an increase in the saturation magnetization directivity of a head core material, or a high frequency. The demand for increasing the magnetic permeability in the region is gradually increasing. In order to meet these demands, a magnetic head using a thin film of a high magnetic permeability metal or a super-quenched ribbon as a head core material has been conventionally proposed. In these magnetic heads, a core material in a form in which a thin film of high-permeability metal or a super-quenched ribbon formed to a thickness corresponding to the track width is sandwiched by a non-magnetic substrate using a resin adhesive as a bonding agent. Is used. According to this core forming method, since the resin adhesive is used as the bonding agent, there are the following problems.

(1) In the case of ultra-quenched ribbon, the surface has irregularities and the flatness is poor, so uniform bonding is difficult.

(2) In the case of a thin film formed by a thin film forming method such as a sputtering method or a vacuum deposition method, the unevenness of the surface can be solved by controlling the surface roughness of the substrate, and the problem of flatness is also caused by the thermal expansion of the substrate. Considering the matching between the coefficient α and the α of the soft magnetic metal thin film to be formed, it can be solved by further performing an appropriate heat treatment. However, the resin adhesive bonding layer is 0.5 μm
When the above-mentioned finite thickness is provided, the bonding layer becomes abnormally concave with respect to precision polishing of the gap facing surface of the core material or sliding of the recording medium after formation of the magnetic head.

(3) Since the resin adhesive is used, the core material cannot be annealed after the gap facing surface is precisely polished, and the work-affected layer extends the effective magnetic gap length.

(4) Peeling occurs over time due to the hygroscopicity of the resin adhesive and the internal stress of the thin film.

(5) Since the resin adhesive is used in the core material forming step, the resin adhesive must be used also in the step of forming the magnetic gap (the resin adhesive is carbonized at the temperature required for glass bonding). ) Similar to the above (4), after the magnetic head is formed, the magnetic gap cannot be maintained constant over time.

Among the above-mentioned problems, the problem of (5) is greatly related to the durability of the magnetic head, and in order to stably use the magnetic head for a long period of time, a resin adhesive is not used, and a member for the magnetic head core is used. Had to be formed. Therefore,
A method of using a low melting point glass instead of a resin adhesive is described in JP-A-59-52419. However, as introduced here, there is a problem that sufficient adhesion strength cannot be obtained even if the nonmagnetic substrate, which is generally an oxide, and the metal magnetic film are adhered with glass. Therefore, in the above-mentioned conventional example, in order to solve this problem, a method of increasing the adhesive strength by oxidizing the surface of the metal magnetic film to form an oxide layer is adopted.

However, iron-silicon-aluminum (Fe-Si-
There is a problem in that it is not preferable in terms of magnetic properties to form an oxide layer by oxidizing an Al) -based soft magnetic metal thin film. However, in the method of directly providing the low melting point glass on the Fe-Si-Al soft magnetic metal thin film, there is a problem in the adhesive strength as conventionally known, and heat treatment is performed at the time of bonding. In this case, the component of the low melting glass is Fe-Si-Al.
Since it diffuses into the soft magnetic metal thin film of the system, there is a problem that the magnetic characteristics are deteriorated.

<Objects of the Invention> The present invention has been made to solve the above-mentioned problems, and obtains a magnetic head having a mechanically strong magnetic gap in a magnetic head using a soft magnetic metal thin film as a head core material. And a member for a magnetic head core for the purpose of preventing the deterioration of magnetic characteristics caused by forming an oxide layer by oxidizing a Fe—Si—Al-based soft magnetic metal thin film. An object of the present invention is to provide a member for a magnetic head core that can prevent deterioration of magnetic characteristics due to diffusion of components of a melting point glass.

<Example> As one example of the present invention, a method of manufacturing a magnetic head using an iron-silicon-aluminum-based high-permeability alloy film produced by an electron beam evaporation method will be described.

FIG. 1 is an explanatory view of a usage state of a core material forming jig for explaining one embodiment of the present invention. FIG. 2 is a layout view of cores at the time of bonding for forming a magnetic gap.

First, an iron, silicon and aluminum alloy film 2 (hereinafter referred to as Fe-Si-Al film) is formed on the non-magnetic substrate 1 by electron beam evaporation to a thickness corresponding to the track width of the magnetic head. At this time, in order to prevent a decrease in magnetic permeability due to eddy current loss in the high frequency region, a thin film core having a laminated structure in which an electrically insulating material such as SiO ₂ or Al ₂ O ₃ is formed as an intermediate layer may be used. Fe-
Considering the matching of the thermal expansion coefficient α with the Si-Al film, α> 1
If a crystal substitute glass of 30 × 10 ⁻⁷ / deg is used, Fe−
After the formation of the Si-Al film, by performing an appropriate heat treatment, the warpage of the entire substrate can be reduced to such an extent that it does not hinder the bonding described later. SiO ₂ or Al ₂ is deposited on the Fe-Si-Al film 2 for the purpose of preventing adsorption of contaminants and oxidation, improving wear resistance, and improving joint strength against thermal fusion due to mutual diffusion with a low-melting glass thin film described later. O ₃ thin film 3
To form. The oxide thin film 3 also plays the role of preventing the components of the low melting point glass formed thereon from diffusing into the Fe-Si-Al film 2 during heat treatment. After the oxide thin film 3 is formed in this manner, heat treatment is performed to eliminate the above-described warpage of the substrate and to improve the soft magnetic characteristics of the Fe-Si-Al film. In this example, 600 ° C. in vacuum for 4 hours or more
Hold at room temperature and then slowly cool. After this heat treatment, SiO ₂
Alternatively, a low melting point glass thin film 4 containing PdO and SiO ₂ as main components and an oxide of an alkali metal as an additive is formed on the thin film of Al ₂ O ₃ by a sputtering method or the like. In this way, the low melting point glass thin film 4, the SiO ₂ or Al ₂ O ₃ thin film 3, the Fe—Si—Al film 2 are formed on the non-magnetic substrate 1 from the upper layer.
The core base material 5 in which the above is formed is prepared. On the other hand, Fe-S
As a bonding substrate 5'for sandwiching the i-Al film 2 with the non-magnetic substrate 1 as a pair, a non-magnetic substrate 1'of the same material as that used for the core base material 5 is formed of the same material. A low melting point glass thin film 4 ′ is prepared.

At this time, if a low melting point glass thin film is formed by a sputtering method, the composition of the target base material and the composition of the formed thin film are different, so that the formed thin film has an α value equivalent to that of a non-magnetic substrate.
It is necessary to previously adjust the composition of the target base material so that the composition has

As shown in FIG. 1, the low melting point glass thin film 4, the core base material 5 and the bonding substrate 5'prepared by the above method,
4'are arranged so as to face each other, pressure P ₁ is applied and held by the jig 6, and heat treatment is performed in this state to bond the core base material 5 and the bonding substrate 5 '. On this occasion,
The lower limit of the temperature required for the heat treatment is limited by the glass transition temperature of the low melting point glass thin films 4 and 4'as the bonding material, and the upper limit is the viscosity of the low melting point glass thin films 4 and 4'decreasing the SiO ₂ or Al ₂ It is limited at a temperature at which the O ₃ thin film 3 is eroded or at a temperature at which bubbles are generated from the low melting point glass thin films 4 and 4'and the bonding layer expands. In the present embodiment, the glass transition temperature of the low melting point glass thin films 4 and 4'is 380 ° C., while the temperature at which the generation of bubbles becomes remarkable is about 570 ° C. or higher, so 500 ° C. is set as the processing temperature. did. The Fe-Si-Al film 2 is formed on the non-magnetic substrate 1,
A magnetic head core member having a structure sandwiched by 1'is produced.

In order to form a magnetic head using the magnetic head core member obtained by the above process, this is cut into an appropriate size, the cut surface is precisely polished, and then the groove 7 for coil winding is processed. The core members 8 and 8'before the gap butting are used. In order to provide the magnetic head with an azimuth angle, in the precision polishing step after cutting, precision polishing may be performed in a state in which the cut core member is held in advance in a jig in consideration of the azimuth angle.

In order to form the magnetic gap, as shown in FIG. 2, a pair of head core members (usually a core member 8'having a coil winding groove and a core member 8 not having a coil winding groove) are provided. Are used as gap spacers and the Fe-Si-A of each core member is inserted through the non-magnetic material 9 having a thickness corresponding to the gap length.
l film 2 is pressed and held while being aligned so that they face each other, and bonding is performed in this state.

For the sake of simplicity, FIG. 2 shows the pattern of the core member arrangement when forming a single magnetic head in a single process, but a magnetic head member capable of forming a plurality of magnetic heads in a single process. Can also be formed. The method in this case is shown in FIGS. 3 and 4. In FIG. 3, the core material is formed in a strip shape, and a plurality of coil winding grooves 7 are provided in the core material. In FIG. 4, a magnetic head is formed by using a block formed by stacking core materials having a plurality of Fe-Si-Al films 2 as one unit. In order to provide the azimuth angle on the magnetic head by the arrangement method shown in FIG. 3, the same steps as those in the case of the single-piece arrangement may be performed. In the arrangement method shown in FIG. 4, preparation of the core block as shown in FIG. 5 is performed. Just do what you want.
FIG. 5 is an explanatory diagram showing a method of forming a block having an azimuth angle θ.

The magnetic head is formed through the steps such as shaping the bonded block obtained by the above-described steps to the bed external dimensions, cylindrical grinding, thinning the entire head thickness, coil winding, and tape polishing.

In the above embodiment, the Fe-Si-Al film formed by the electron beam evaporation method was used as the soft magnetic metal thin film, but a film formed by the sputtering method or a thin film using another soft magnetic metal material is also used in the practice of the present invention. Does not cause any hindrance.

<Effects of the Invention> As described above, according to the present invention, a soft magnetic metal thin film made of Fe—Si—Al and an oxide thin film made of SiO ₂ or Al ₂ O ₃ are formed on a non-magnetic substrate made of crystallized glass. And a low-melting glass containing an alkali metal oxide as an additive are formed in this order, a strong bonding state can be obtained, and the Fe-Si-Al-based soft magnetic metal thin film is oxidized. (EN) Provided is a member for a magnetic head core, which does not cause a problem of deterioration of magnetic characteristics caused by forming an oxide layer and can prevent deterioration of magnetic characteristics due to diffusion of components of a low melting point glass. it can. Further, by using the magnetic head core member according to the present invention, it is possible to use glass for forming the magnetic gap, which makes it possible to easily manufacture the magnetic head and also improve durability. it can.

[Brief description of drawings]

FIG. 1 is an explanatory view of a usage state of a core material forming jig for explaining an embodiment of the present invention. FIG. 2 is a layout view of cores at the time of bonding for forming a magnetic gap by single processing. 3 and 4 are layout diagrams of cores at the time of bonding for simultaneously forming a plurality of magnetic heads. FIG. 5 is an explanatory diagram for explaining a process of forming a block having an azimuth angle θ. 1, 1 ': Non-magnetic substrate 2: Fe-Si-Al film 3: Oxide thin film 4: Low melting point glass thin film 6: Jig 7: Coil winding groove 9: Gap spacer

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Mitsuhiko Yoshikawa 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (56) References JP-A-59-52419 (JP, A) JP-A-59 -58613 (JP, A)

Claims (1)

[Claims] 1. On a non-magnetic substrate made of crystallized glass, F
A soft magnetic metal thin film made of e-Si-Al, an oxide thin film made of SiO ₂ or Al ₂ O ₃ and a low melting point glass containing an oxide of an alkali metal as an additive are formed in this order. Members for magnetic head cores.