JPH03113705A - Production of composite magnetic head - Google Patents

Abstract

PURPOSE:To prevent the yield from being deteriorated due to the bubbles in a gap, etc., by oxidizing the surface layer parts of adhesive strength intensifying films and interposing and forming these parts as the diffusion preventive layers to metallic thin films. CONSTITUTION:The layers formed by forcibly oxidizing the surface layer parts of the adhesive strength intensifying films 6 are formed as the diffusion preventive layers 12 between the metallic thin films 5 and the adhesive strength intensifying films 6 to, for example, 100 to 300Angstrom thickness. The reactive sputtering by gaseous oxygen is executed by introducing gaseous oxygen at the time of depositing and forming the adhesive strength intensifying films 6 consisting of Cr or the like by a sputtering method or the like first on the edge parts of cores 2a, 2b, i.e. the end faces on the gap(g) forming side, by which the surface layer parts of the intensifying films 6 are forcibly oxidized and are interposed as the diffusion preventive layers 12 therein at the time of forming the above-mentioned diffusion preventive layers 12. The diffu sion of the metal forming the intensifying films 6 into the metallic thin films is obviat ed in this way and the degradation in the yield due to the bubbles in the gap, etc., arising therefrom is prevented. Further, the deterioration in the magnetic characteristics of the metallic thin films themselves is prevented and the reliability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head and a method for manufacturing the same.
Parallel type MIG (Metal
The present invention relates to a magnetic head that achieves high-density recording by improving the gap structure of the in-gap head.

In the field of secondary boiling 4U magnetic recording, higher recording density and higher frequency information signals are being recorded, and in response to this trend, Fe is being used in magnetic powder as a magnetic recording medium.

So-called metal tapes using ferromagnetic metal powders such as Co and Ni, and so-called vapor deposition tapes in which magnetic metal materials are directly deposited on a base film using vacuum thin film forming techniques such as vapor deposition, have been put into practical use and have become popular. ing. Under these circumstances, for magnetic heads, the core material of the magnetic head has a high saturation magnetic flux density, for example, in order to perform good recording and reproduction on magnetic recording media that have high coercive force and residual magnetic flux density.

Various properties are required, such as high magnetic permeability.

It is difficult to manufacture a magnetic head that satisfies these requirements from a single ferromagnetic oxide material such as ferrite material;
Therefore, a so-called composite magnetic head has been proposed in which the magnetic head is constructed by combining a ferromagnetic metal thin film having a high saturation magnetic flux density, such as Sendust. As is already known, this Sendust is Fe+AnotSX
It is an alloy whose main composition is
As shown in the June 981 issue P2O6, the saturation magnetic flux density Bs is 9500 Gauss, and the coercive force Hc is 20.
m0e.

Effective magnetic permeability μeff is 30000 at 300Hz
It has excellent properties such as a Vickers hardness of 500 Hv.

In the above-mentioned conventional composite magnetic head, for example, as shown in FIGS. 4 to 6, a magnetic core portion 2a r 2 has a winding locking groove 9a*9b% and a winding insertion hole 10 formed therein.
In order to improve the adhesion between the ferrite which is the material of b and the metal thin film 5 forming the magnetic gap g on the top end surface 8 of the core chip, the edge portion 2a forming the magnetic gap g of each core 2a, 2b is used. , 2b by vapor deposition or sputtering (in an inert gas atmosphere, especially argon gas), etc., to coat the adhesion strength-enhancing film 6 with a film thickness of 500 to 700%.
A thin film 5 of metal such as sendust is deposited on top of the thin metal film 5 made of sendust or the like. At this time, the adhesion-strengthening film 6 is selected from metals included in Groups 1 Va to VIa of the periodic table of elements, and Cr and Ti are often used, for example. The magnetic head 1 was obtained by winding a copper wire 7 around the magnetic head portion 2 formed in this manner.

In addition, the above-mentioned parallel type MIG head 1 has a laminated structure in which an oxide film for preventing diffusion, that is, a thin film 14 such as S10□ is sandwiched between these metals □ alone as the adhesion strength film 6. , it has the advantage of being easy to manufacture due to the simple grooving process. However, in order to manufacture the core chip 2, a desired thin film is formed by sputtering or the like, and then a heat treatment process such as annealing or glass fusion is performed. It thermally diffuses into the thin film 5 and deteriorates the magnetic properties near the interface between the metal thin film 5 and the adhesion reinforcing film 6. That is, when the deteriorated layer 5a of the metal thin film 5 is formed parallel to the magnetic gap g, the magnetic resistance of this portion increases, resulting in a pseudo gap gtsg2 parallel to the magnetic gap g. In this case, when reproducing the information written on the magnetic medium 11 by the MIG head 1.15, noise is generated in the information, and error operations that make accurate reproduction difficult occur frequently. Furthermore, due to the influence of the above-mentioned diffusion, the gap forming film surface g-
Minute irregularities occurred in the 1gb, making it difficult to form an accurate magnetic gap and causing air bubbles inside the gear and major gear defects.

In addition, as shown in FIGS. 7 to 8, a magnetic herad core 15 is provided with a thin layer 14 such as 5102 as a diffusion prevention film.
Also, the thickness of the thin layer 14 such as SIO□ is 300 Å.
If it is not thicker, it will not be possible to stop the diffusion, and if it is too thick, it will itself act as a pseudo gap,
There is a problem that the adhesive strength due to Cr deteriorates,
Controlling the film thickness was extremely difficult.

SUMMARY OF THE INVENTION Accordingly, a main object of the present invention is to provide a parallel type MIG head that is easy to manufacture and has a structure in which spurious pulses are less likely to occur, and a method for manufacturing the same.

・, Komeno 2 The present invention is characterized in that the edge portions forming the magnetic gap of a pair of cores made of ferrite contain elements from Va to Va in the periodic table.
In a device in which a thin ferromagnetic metal film having a high saturation magnetic flux density is provided in parallel to the magnetic gap through an adhesion-strengthening film made of a metal in the Vla group, particularly Cr or Ti, the surface layer of the adhesion-strengthening film is is characterized in that a diffusion prevention layer of a predetermined thickness is formed between the metal thin film and the metal thin film.

■ In addition to providing a ferromagnetic metal thin film through a force-enhancing film,
By providing a diffusion prevention film, that is, a diffusion prevention layer in which the surface layer of the adhesion-strengthening film is forcibly oxidized, the metal forming the adhesion-strengthening film can be melted at the temperature during annealing or core bonding. Prevents diffusion into the thin film.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. The same reference numerals as in FIGS. 4 to 8 indicate the same parts, and the explanation thereof will be omitted.

A feature of the present invention is that a layer formed by forcibly oxidizing the surface layer of the adhesion-strengthening film 6 is formed as a diffusion prevention layer 12 between the metal thin film 5 and the adhesion-strengthening film 6 to a thickness of, for example, 100 to 300 people. It was formed through an intervening process.

When forming the above-mentioned diffusion prevention layer 12, core 2a+2b
The edge portion 2a1.2bl, that is, the magnetic gear g
When first depositing the adhesion-strengthening film 6 of Cr or the like on the end face on the formation side by sputtering or the like, oxygen gas is introduced and reactive sputtering is performed using the oxygen gas to improve the surface layer of the adhesion-strengthening film 6. For example, a thickness of about 100 to 300 λ is forcibly oxidized and interposed as a diffusion prevention layer 12. At this time, the gas pressure was 4.0XfO-2 Torr, and the introduction ratio of oxygen gas and argon gas was 1:1 or 3:
Set to 2.

As another example, after forming the adhesion strength film 6 to a desired thickness (500 to 700 layers) by sputtering, an oxygen gas atmosphere (4,0X10-''Torr f00%0
By annealing at 300[deg.] C. for 20 to 30 minutes at □), only the surface layer of the adhesion reinforcing film 6 is forcibly oxidized to form the diffusion prevention layer 12. Thereafter, a metal thin film 5 such as sendust is deposited to a predetermined thickness by sputtering, and a non-magnetic material such as S is applied to form a gap spacer.
Sputtering is performed to obtain a desired gap length such as 10°, and the glass 3 is formed by butting both cores 2a and 2b together.
, 4 to form a zygote.

According to the above embodiment, when bonding the glass, the core 2
When heating a s 2 b, the metal such as Or forming the adhesion strengthening film 6 does not diffuse into the metal thin film 5, and deterioration of the magnetic properties of the metal thin film 5 is prevented. Further, even if the diffusion prevention layer, that is, the oxide layer 12 is thin, deterioration of the magnetic properties can be prevented, and the enhancement of adhesion by Cr is not hindered. Therefore, the axis of the degraded layer of magnetic properties parallel to the magnetic gap g is no longer formed in the metal thin film 5, resulting in pseudo gear clouding. Bo, does not occur. Therefore, when reproducing information written on the magnetic medium 11 by the MIG head 13 according to the present invention, an undesired rise does not occur in the output reproduction waveform, and accurate reproduction can be obtained.

In the above embodiment, Sendust alloy was used as the high saturation magnetic flux density material, but the present invention can also be applied to magnetic heads using other materials such as ferromagnetic amorphous metal alloys, so-called amorphous alloys, to achieve similar effects. can get.

According to the present invention, a magnetic gap is formed on the top end surface of a core chip formed by joining and integrating a pair of ferrite cores,
When a thin ferromagnetic metal film is provided on the edge of the core located in the magnetic gap via an adhesion-strengthening film, a diffusion prevention film is provided in between, so that the metal forming the adhesion-strengthening film is not absorbed into the metal thin film. It is possible to improve the yield loss caused by air bubbles in the gear hub and large defects in the gear hub due to the diffusion, and also to prevent deterioration of the magnetic properties of the metal thin film itself, resulting in sufficiently large output characteristics and improved reliability.

[Brief explanation of drawings]

1 and 2 are a perspective view and a plan view showing an embodiment of the magnetic head according to the present invention, and FIG. 4, 5, and 7 are a perspective view and a plan view showing a specific example of a conventional magnetic head, and FIG. 6 is an enlarged sectional view of a main part showing a portion near the magnetic gap of the magnetic head shown in FIG. 8 is an enlarged sectional view of a main part of the magnetic head shown in FIG. 7, showing a portion near the magnetic gap. 2... Core chip, 2a, 2b... Core, 5... Metal thin film, 6... Adhesive force strengthening film, 8... Top end portion, 12... Diffusion prevention layer, g... Magnetism gap.

Claims (1)

[Claims] At the edge part forming the magnetic gap of a pair of cores made of ferrite, which is a ferromagnetic oxide, there is an element IVa in the periodic table.
-A thin ferromagnetic metal film having a high saturation magnetic flux density is provided in parallel to the magnetic gap via an adhesion-strengthening film made of a group VIa metal, in which the surface layer of the adhesion-strengthening film is oxidized, A method for manufacturing a composite magnetic head characterized in that a metal thin film is interposed and formed as a diffusion prevention layer.