JPH0652511A - Magnetic head and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a magnetic head which has such a film thickness that does not affect the spacing between the head and a magnetic recording medium and an excellent wear resistance by coating the sliding surface of the head which slides on the recording medium with a chromium nitride film. CONSTITUTION:The sliding surface of the magnetic head which slides on a magnetic recording medium is coated with a chromium nitride thin film which contains nitrogen by 20-60atm.%, is composed of a polycrystalline material having diffraction peaks at 2theta of about 37.4 deg. and 43.4 deg. at the time of X-ray diffraction analysis, and has a film thickness of 50-1,000Angstrom . At the time of forming the thin film, a negative bias voltage of 0V or lower is applied across the sliding surface of the magnetic head.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an audio pre-coder, a video pre-coder and a digital audio recorder.
The present invention relates to a magnetic head in a magnetic recording / reproducing apparatus such as a precoder, a hard disk, a floppy disk, and a magnetic card, and a manufacturing method thereof.

[0002]

2. Description of the Related Art A magnetic head slides a magnetic recording medium such as a magnetic tape or a magnetic disk on a sliding surface to perform recording, reproduction and erasing. Since it is used, wear on the sliding surface cannot be avoided, and this wear causes deterioration of the magnetic head.

Various devices have been proposed to solve this problem. For example, a method has been proposed in which a boron-donating material is applied to the sliding surface of a magnetic head and an annealing process is performed to form a boron diffusion layer, thereby hardening the sliding surface and improving wear resistance. (Japanese Patent Publication No. 56-1682)
In addition, a method has also been proposed in which hardened metal atoms are injected and hardened into the sliding surface by ion implantation to improve wear resistance. On the other hand, it has been proposed to improve wear resistance by coating a thin film having high hardness on the sliding surface of the magnetic head. For example, a method has been proposed in which a boron nitride thin film is formed on a thin film containing at least one of Group IIIb, Group IVa, and Group IVb formed on the sliding surface of a magnetic head (Japanese Patent Laid-Open No. 3-267363). ).

[0004]

However, in these methods, the method of thermal diffusion of boron and the ion implantation of boron requires strict control of temperature, cooling rate, etc., resulting in high production cost. Further, there is a problem that the inside of the magnetic head is adversely affected due to higher processing temperature and impact of ions. The method for forming a boron nitride thin film also has a two-layer structure of an intermediate layer and a boron nitride film, which deteriorates productivity and often improves the wear resistance. Is 0.1 μm
There is a problem that the thickness becomes thicker, and this becomes the spacing between the head and the recording medium to deteriorate the electromagnetic conversion characteristics, and the wear resistance is insufficient even with this thickness.

In view of the above problems, the present invention provides a magnetic head having a film thickness that does not deteriorate electromagnetic conversion characteristics and having improved wear resistance, and a method for manufacturing the same.

[0006]

In order to solve the above-mentioned conventional problems, the magnetic head according to the present invention is characterized in that a protective film made of a chromium nitride film is formed on the head sliding surface.

[0007]

The nitrogen composition is 20 to 60 atomic%, the X-ray diffraction analysis is made of a polycrystalline body in which diffraction peaks are observed at 2θ of around 37.4 degrees and around 43.4 degrees, and the film is formed. By coating a chromium nitride film satisfying the condition that the thickness is in the range of 50 to 1000 Å on the sliding surface of the magnetic head, the film thickness which is not affected by the spacing between the head and the medium is extremely excellent. A magnetic head having wear resistance can be provided.

[0008]

EXAMPLES Specific examples will be described in detail below. The reactive high frequency magnetron sputtering method was used for the production of chromium nitride. A chromium target having a diameter of 6 inches was used as a target, and high frequency discharge was performed in a mixed gas of argon and nitrogen to form a film. The nitrogen composition was controlled by changing the mixing ratio of argon and nitrogen. The substrate was water cooled, the sputtering power was 400 W, and the sputtering pressure was 8 mTorr. In addition, a negative DC bias voltage was applied at the time of fabrication in order to improve the crystallinity and adhesion of the nitride film. The structure of the chromium nitride film was analyzed by X-ray diffraction analysis, and the amount of nitrogen was analyzed by Auger electron spectroscopy.

The mechanical strength of the chromium nitride film was measured by using a scratch tester (manufactured by Nishi Engineering Co., Ltd.) and a load of 30 with a polishing tape (WA10000 manufactured by Nippon Micro Coating Co., Ltd.).
It was evaluated by g. The results after sliding 1000 times are shown in (Table 1). Chromium metal film with nitrogen content of 0 atom% or nitrogen content of 1
When the nitrogen content was as small as 0 atom%, many large scratches and peeling occurred on the surface after the scratch test. Similarly, when the nitrogen content was 70 atomic%, many large scratches and peeling occurred on the surface after the scratch test. However, the amount of nitrogen is 2
Within the range of 0 to 60 atom%, scratches and peeling did not occur at all on the surface after the scratch test. Therefore, a mechanically strong nitride film can be obtained within the range of 20 to 60 atomic% of nitrogen.

[0010]

[Table 1]

The structure of the chromium nitride film changes depending on the amount of nitrogen and negative DC bias. FIG. 1 shows the relationship between the diffraction peak intensity and the nitrogen content of chromium nitride in the X-ray diffraction analysis of the chromium nitride film. Copper Kα1 radiation was used for X-ray diffraction analysis. In the case of zero nitrogen content, that is, a chromium metal thin film, a diffraction peak of the (110) plane of chromium having a strong body-centered cubic lattice is observed. This peak gradually weakens and becomes amorphous as the amount of nitrogen increases. When the amount of nitrogen is 20 atomic% or more, diffraction peaks appear at 2θ of around 37.4 degrees and around 43.4 degrees. It is considered that the former is due to the (111) face of chromium nitride in the face-centered cubic lattice, and the latter is due to the (200) face of chromium nitride in the face-centered cubic lattice. Therefore, these faces are oriented in crystalline chromium nitride. It is considered to be polycrystalline, but details are unknown. 70 atomic% nitrogen
If it exceeds, the structure of chromium nitride becomes amorphous. FIG. 2 shows the relationship between the diffraction peak intensity and the negative DC bias voltage in the X-ray diffraction analysis of the chromium nitride film. It can be seen from FIG. 2 that the crystallinity of the chromium nitride film changes due to the negative bias voltage. When the negative bias voltage becomes -100V, an amorphous film is formed.

In order to evaluate the wear resistance of these films, a magnetic head was coated and a wear resistance test was conducted. The film thickness of chromium nitride was kept constant at 500Å. The wear resistance was evaluated by incorporating each magnetic head in a cassette deck mechanism, using a pad pressure of 20 g, and using a magnetic tape made of iron oxide. The head used for the evaluation of wear resistance is NiZn ferrite in which the core material is NiZn ferrite and barium titanate is used in the cover material.
Ferrite / barium titanate head, core material, cover
An AlTiC / AlTiC head using AlTiC was used for both materials. The tape running test is 1 at room temperature and normal humidity.
It was replaced with a new magnetic tape at 00 hours, and the operation was performed for 1000 hours.

[0013]

[Table 2]

Table 2 shows the results of abrasion resistance evaluation. The crystalline chromium nitride films having the diffraction peaks at 2θ of about 37.4 degrees and about 43.4 degrees obtained by controlling the nitrogen amount and the DC bias voltage as shown in Examples 5 to 9 were obtained. It can be seen that it has excellent durability as compared with the amorphous chromium nitride film as shown in Comparative Examples 4 to 7.

Table 3 shows the results of abrasion resistance when the chromium nitride film thickness was changed. It can be seen from Table 3 that sufficient wear resistance can be obtained even if the thickness of the nitride film is small. The thickness of chromium nitride is preferably 50 to 1000Å to obtain high wear resistance and reproduction output.

[0016]

[Table 3]

[0017]

As described above, according to the present invention, the protective film made of the chromium nitride film is formed on the sliding surface of the head and the nitrogen composition is 20 to 20.
60 atom%, 2θ is 3 in X-ray diffraction analysis
Slide the magnetic head with a chromium nitride film that satisfies the conditions that it is made of a polycrystalline material with diffraction peaks around 7.4 degrees and 43.4 degrees, and that the film thickness is in the range of 50 to 1000Å. By coating the surface, extremely excellent wear resistance can be realized with a film thickness that is not affected by the spacing between the head and the medium.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the diffraction peak intensity and the nitrogen content of chromium nitride in an X-ray diffraction analysis of a chromium nitride film according to an example of the present invention.

FIG. 2 is a graph showing the relationship between the diffraction peak intensity and the negative DC bias voltage in the X-ray diffraction analysis of the chromium nitride film of the example of the present invention.

Claims (5)

[Claims] 1. A magnetic head having a chromium nitride thin film formed on a sliding surface with respect to a magnetic recording medium. 2. A magnetic head according to claim 1, wherein the chromium nitride thin film has a nitrogen composition of 20 to 60 atom%. 3. The chromium nitride thin film is composed of a polycrystalline body in which diffraction peaks are observed at 2θ of about 37.4 degrees and about 43.4 degrees in X-ray diffraction analysis.
Alternatively, the magnetic head according to any one of 2 and 3. 4. A chromium nitride thin film having a thickness of 50 to 1000 Å
4. The magnetic head according to claim 1, wherein the magnetic head is in the range. 5. A method of manufacturing a magnetic head, wherein a negative bias voltage of zero volt or less is applied to a sliding surface with a magnetic recording medium when forming a chromium nitride thin film.