JPH0536016A - Magnetic head - Google Patents

Abstract

PURPOSE:To eliminate a pseudo gap and to enhance the joint strength of a gap of the magnetic head of a metal-in type formed with magnetic metallic films of a high saturation magnetic flux density on the opposite surfaces of a pair of magnetic cores used for a magnetic recording and reproducing device. CONSTITUTION:A nitride film 4 consisting of aluminum nitride or silicon nitride, etc., is formed on the magnetic metallic film 3s formed on the opposite surfaces of a pair of the magnetic cores 1, 2. The nitride film 4 acts as an antireaction film in common use as a magnetic gap and can prevent the interreaction and diffusion of the magnetic metallic films 3 and adhering glass 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal in-gap (Meta) in which a magnetic metal film having a high saturation magnetic flux density is formed on the abutting surfaces of a pair of magnetic cores used in a magnetic recording / reproducing apparatus.
l in Gap (hereinafter referred to as MIG) type magnetic head.

[0002]

2. Description of the Related Art In recent years, with the increasing density of magnetic storage devices, the practical use of thin film media having high coercive force has been advanced. For this reason, it is difficult for the conventional ferrite head to deal with it, and Fe-Al having a high saturation magnetic flux density is formed on the gap facing surface.
Practical application of MIG type magnetic heads provided with a metal magnetic film such as -Si alloy is progressing.

A conventional MIG type magnetic head will be described below. As shown in FIGS. 12 and 13, a magnetic core 1 mainly composed of a slider and a magnetic core 2 mainly composed of a winding portion.
Form a magnetic circuit with a magnetic gap 7 made of non-metal oxide such as SiO ₂ sandwiched therebetween. On the surface of the magnetic core 2 facing the magnetic core 1, a metallic magnetic film 3 of Fe—Al—Si alloy or the like is provided, and the magnetic core 1 and the magnetic core 2 are bonded to each other by an adhesive glass 6
Are joined together.

In the above structure, a layer having deteriorated soft magnetic characteristics is formed at the interface between the magnetic core 2 and the metal magnetic film 3, which causes a pseudo gap and is a large barrier in increasing the density. Various methods have been proposed as a method for avoiding this pseudo gap. However, basically, the material of the metal magnetic film 3 and the magnetic core 2 is prevented from diffusing, and the interface between the metal magnetic film 3 and the magnetic core 2 is softened. Measures are taken to prevent deterioration of magnetic characteristics.

In the MIG type magnetic head, a diffusion prevention layer is provided at the interface between the metal magnetic film and the magnetic core, or a gap is formed, as described in Journal of Applied Magnetics, 13, 89-94 (1989). Studies are underway to lower the temperature. When the gap is formed by the glass fusing method which is the current mainstream of gap formation, PbO-based low melting point glass is used as the adhesive glass 6 as the gap forming temperature is lowered.

[0006]

However, in the above-mentioned conventional structure, the glass itself becomes brittle as the melting point of the adhesive glass 6 is lowered, and many cracks and cracks occur in the working process, so that sufficient gap bonding strength can be obtained. The reliability of the magnetic core 1 and the magnetic core 2 is reduced, and the SiO ₂ thin film 7 as a magnetic gap material reacts with the PbO-based adhesive glass 6 and is corroded when the magnetic core 1 and the magnetic core 2 are joined. There is a problem that the film 3 and the adhesive glass 6 react with each other to cause erosion of the adhesive glass 6 to reduce the strength of the glass itself and weaken the bonding strength between the magnetic core 1 and the magnetic core 2.

The present invention solves the above-mentioned conventional problems, and provides a magnetic head having a strong gap junction strength in a MIG type magnetic head using a metal magnetic film having a high saturation magnetic flux density without generating a pseudo gap. The purpose is to do.

[0008]

In order to achieve this object, the magnetic head of the present invention is a MIG in which a metal magnetic film having a high saturation magnetic flux density is formed on the gap facing surfaces of a pair of magnetic cores.
In this type of magnetic head, a nitride film is formed on a metal magnetic film, and a lead-based glass thin film is further formed on the nitride film.

[0009]

With this configuration, the metal magnetic film and the adhesive glass for joining the magnetic core do not come into direct contact with each other, and the metal magnetic film and the adhesive glass do not react.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2 showing an embodiment of the present invention, the same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIGS. 1 and 2, a magnetic head in which a magnetic circuit is constructed by sandwiching a nitride film 4 and a glass thin film 5 which are magnetic gap materials on the opposing surfaces of the magnetic core 1 and the magnetic core 2 will be described below. Will be explained.

A metal magnetic film 3 of Fe--Al--Si alloy having a thickness of 1 to 4 .mu.m is formed on the surface of the magnetic core 2 made of high-permeability ferrite such as Mn--Zn ferrite facing the magnetic core 1 by the sputtering method. To form. (It should be noted that the sputtering conditions shown in the present embodiment are examples, and it is necessary to set conditions suitable for various devices and targets.) Next, on the metal magnetic film 3, AlN, which will become a magnetic gap,
A nitride film 4 of SiN, SiNO or the like is formed by a sputtering method under the sputtering conditions shown in (Table 1) so as to have a thickness of 0.1 to 0.2 μm.

[0014]

[Table 1]

On top of that, PbO-SiO ₂ -B ₂ O
_Using a lead-based glass target having a composition such as ₃ and an Ar pressure of 4 × 10 ⁻² Torr, an RF input power of 200 W, and a substrate temperature of 100 ° C., a sputtering method was performed to obtain 0.05.
The glass thin film 5 is formed to have a thickness of 0.1 μm.

Next, the magnetic core 1 mainly composed of the slider and the magnetic core 2 having the nitride film 4 and the glass thin film 5 forming the magnetic gap on the metal magnetic film 3 are opposed to each other, and the magnetic core 1 and the magnetic core 2 are opposed to each other. A PbO-based low-melting-point adhesive glass 6 is adhered over this to join the magnetic core 1 and the magnetic core 2.
Finally, the magnetic core 2 is wound to complete the magnetic head.

In the present embodiment, the nitride film 4 and the glass thin film 5 forming the magnetic gap are formed only on the magnetic core 2 having the metal magnetic film 3. However, the magnetic core 1 mainly consisting of the slider and the metal magnetic film. It may be formed on the gap forming surface of the magnetic core 2 having the film 3 so as to be divided into each half of the required thickness.

With respect to the magnetic head in which the nitride film 4 is formed in the magnetic gap of this embodiment and the magnetic head in which the SiO ₂ thin film 7 is formed in the magnetic gap of the conventional example, each constituent atom at the interface between the metal magnetic film and the magnetic gap material. The diffusion state of the sample will be described based on data obtained by X-ray photoelectron spectroscopy analysis of the sample.

As a combined magnetic gap sample of the conventional example, Fe-Al-on a Mn-Zn ferrite substrate.
A Si-based alloy having a thickness of 3.5 μm formed by a sputtering method and SiO ₂ having a thickness of 0.1 μm formed thereon was used as a first sample.
The second sample was subjected to heat treatment at 50 ° C.
As a combination sample of the magnetic gap of the embodiment of the present invention, Fe—Al—Si was formed on a Mn—Zn ferrite substrate.
Form a 3.5μm thick alloy by sputtering,
A third sample was formed by forming SiN on it to a thickness of 0.1 μm, and the third sample was heat-treated at 550 ° C. to obtain a fourth sample. The diffusion and reaction states of the first to fourth samples were observed and measured from the surface of the SiO ₂ or SiN film by X-ray photoelectron spectroscopy. The measurement results of the first sample and the second sample are
The third sample and the fourth sample are shown in FIGS. 3 and 4, respectively.
The measurement results of the sample are shown in FIGS. 5 and 6, respectively. The vertical axis represents the intensity of each atom, and the horizontal axis represents the etching time (minutes).
This indicates the depth from the film surface. As is clear from FIGS. 3 and 4, when heat treatment at 550 ° C. is performed, Si
It can be seen that Al is shifting to the SiO ₂ side at the interface between O ₂ and the Fe-Al-Si alloy film.

As is clear from FIG. 5 and FIG.
At the interface between N and the Fe-Al-Si alloy film, there is no shift of Al even if the heat treatment at 550 ° C is performed, and SiN and Fe-Al
It can be seen that the -Si alloy film does not react or diffuse. Next, the reaction / diffusion state between the adhesive glass 6 and the magnetic gap material will be described. As a sample of a conventional example, an Fe-Al-Si alloy was formed on a Mn-Zn ferrite substrate to a thickness of 3.5 μm by a sputtering method, SiO ₂ was formed to a thickness of 0.1 μm, and a glass thin film 5 was formed to a thickness of 0.05 μm. Then, an adhesive glass 6 having a thickness of 0.1 μm is formed thereon by using a target having the same component as that of the adhesive glass 6.
A heat treatment was performed at 0 ° C. to prepare a fifth sample. On the other hand, as a sample of the example of the present invention, a sixth sample was prepared under the same conditions except that SiO ₂ of the fifth sample was changed to AlN. The measurement results of the X-ray photoelectron spectroscopy analysis of the fifth sample and the sixth sample are shown in FIGS. 7 and 8, respectively. As is clear from FIG. 7, the gap material is made of Si.
It can be seen that when O ₂ is used, the adhesive glass 6 and the gap material react and diffuse and mix. On the other hand, when AlN is used as the gap material, it is clear from FIG. 8 that the adhesive glass 6 and the gap material do not react and diffuse. As described above, by using the nitride film 4 of AlN or the like as the gap material, it is possible to prevent the diffusion and reaction near the interface between the metal magnetic film 3 and the chamber material film 4 of the gap material or the adhesive glass 6.

As a result, the chambering film 4 used as the gap material acts as a reaction preventing film between the metal magnetic film 3 and the adhesive glass 6, and the reducing action of the adhesive glass 6 by the metal magnetic film 3 is prevented, so that the glass It is possible to obtain a magnetic head having a high bonding strength, which is free from deterioration and causes no microcracks in the magnetic core 2 during processing.

The adhesive strength of the magnetic head samples No. 4 to 6 of the present embodiment, the adhesive strength of the magnetic head samples No. 1 to 3 of the conventional example, and the coil misalignment defect rate are shown in comparison with each other (Table 2).

[0023]

[Table 2]

The adhesive strength is the width dimension l as shown in FIG.
A dummy head 8 sliced to 300 μm,
In Table 2, N is the number of samples, X is the average value (unit: g) σ _{N-1, and} the standard deviation value.

As is clear from this (Table 2), in the magnetic head according to the embodiment, the joining temperature of the magnetic cores 1 and 2 is 50.
It can be seen that even at a low temperature of 0 ° C., a strong adhesive strength is exhibited, and similarly to the adhesive strength, the defective rate of coil dislocation is significantly improved and an excellent effect is obtained.

10 and 11 show the results of observing the adhesive glass 6 of the magnetic head of Sample No. 4 of the present embodiment and the magnetic head of Sample No. 1 of the conventional example from the side with a polarizing microscope. In the conventional magnetic head of FIG. 10, many bubbles 10 are generated near the metal magnetic film 3, whereas in the magnetic head of the present embodiment of FIG. 11, the generation of the bubbles 10, that is, the deterioration of the glass is small. I understand.

As described above, according to this embodiment, by providing the nitride film 4 of AlN or SiN as the gap material, mutual diffusion of the metal magnetic film 3 and the adhesive glass 6 can be prevented, and the magnetic cores 1 and 2 can be prevented. Sufficient gap bonding strength can be obtained even at a low bonding temperature of 550 ° C. or lower. Therefore, the junction temperature of the magnetic cores 1 and 2 can be lowered, and a high-performance magnetic head having a strong gap junction strength and excellent magnetic characteristics can be easily obtained with a high yield.

Although the magnetic head in which the metal magnetic film 3 is formed on one of the magnetic cores 2 has been described in the present embodiment, a magnetic head in which the metal magnetic film 3 is formed on both of the magnetic cores 1 and 2 has been described. Can also be applied, and in this case an even better effect can be obtained.

[0029]

As is apparent from the above description of the embodiments, the present invention provides a metal magnetic film in a MIG type magnetic head in which a metal magnetic film having a high saturation magnetic density is formed on the opposing surfaces of a pair of magnetic cores. With a structure in which a nitride film is formed on and a lead-based glass thin film is further formed thereon, the pseudo gap can be eliminated, and an excellent magnetic head having a strong gap junction strength can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a magnetic head according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

[Fig. 3] Reaction at the interface between SiO ₂ and FeAlSi alloy
Graph of X-ray photoelectron spectroscopy analysis showing the diffusion state

FIG. 4 SiO ₂ and FeAlSi heat treated at 550 ° C.
Graph of X-ray photoelectron spectroscopy analysis showing the reaction / diffusion state at the interface of a Ni-based alloy

FIG. 5 is a graph of X-ray photoelectron spectroscopy analysis showing the reaction / diffusion state at the interface between SiN and FeAlSi-based alloy.

FIG. 6 is a graph of X-ray photoelectron spectroscopy analysis showing the reaction / diffusion state at the interface between SiN and FeAlSi-based alloy heat-treated at 550 ° C.

FIG. 7 is a graph of X-ray photoelectron spectroscopy analysis showing the reaction / diffusion state at the interface between the adhesive glass and SiO _2.

FIG. 8 is a graph of X-ray photoelectron spectroscopy analysis showing the reaction / diffusion state at the interface between the adhesive glass and AlN.

FIG. 9 is a perspective view showing the concept of a method of testing the adhesive strength of a magnetic head.

FIG. 10 is a cross-sectional view of an essential part showing the state of bubbles generated in an adhesive glass of a conventional magnetic head, as an observation result with a polarization microscope.

FIG. 11 is a cross-sectional view of essential parts showing the state of bubbles generated in the adhesive glass of the magnetic head of one embodiment of the present invention as observed by a polarization microscope.

FIG. 12 is a perspective view of a main part of a conventional magnetic head.

13 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

1,2 magnetic core 4 Nitride film 5 glass film

Claims (2)

[Claims] 1. A magnetic head in which a metal magnetic film having a high saturation magnetic flux density and a gap material are arranged and bonded to the opposing surfaces of a gap formed by a pair of magnetic cores, and AlN or AlN is formed on the metal magnetic film. Forming a nitride film of SiN,
A magnetic head in which a glass thin film is formed on the chamber film and a gap length is defined by the nitride film and the glass thin film. 2. The magnetic head according to claim 1, wherein the metal magnetic film is an Fe—Al—Si alloy.