JPH0817012A - Magnetic head and its production - Google Patents

Abstract

PURPOSE:To improve the peeling strength between a ferrite substrate and a ferromagnetic metal thin film and to improve the production yield and quality. CONSTITUTION:A pair of magnetic half bodies are joined into one body to form a magnetic gap. On the surface of core substrates 2a, 2b comprising an oxide magnetic material facing to a medium, a groove 5 to regulate the track width and a ferromagnetic thin film 1 are formed. On the surface of the magnetic gap not facing to the medium where no groove 5 to regulate the track width is formed, a reaction-preventing film 4 is formed between the ferromagnetic metal thin film 1 and substrates 2a, 2b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention relates to VTR, DAT, F
The present invention relates to a magnetic head suitable for recording and reproducing information at high density on a magnetic recording medium having a high coercive force used for a DD, an HDD and the like, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, magnetic heads using ferrite (oxide magnetic material) have been used in magnetic recording devices such as VTRs. However, in order to record / reproduce information at high density, it is necessary to increase the coercive force of the recording medium, and metal tapes having a coercive force of more than 80 kA / m have been used. Therefore, for the purpose of avoiding magnetic saturation of the magnetic head, a ferromagnetic metal material having a high saturation magnetic flux density, such as a Co-based amorphous alloy, a sendust alloy, a Co-based superstructure nitride alloy, or a Fe-based nitride alloy, is used in a part of the magnetic core. A magnetic head using is developed and partially put into practical use.

As an example of these magnetic heads, sputtering is performed on the gap forming surface of a core half body made of ferrite.
There is a metal in-gap head (hereinafter referred to as MIG head) in which a ferromagnetic metal thin film is formed by a vapor deposition method or the like. In particular, the ferromagnetic metal thin film 1 as shown in FIG.
parallel type MIG having a structure arranged in parallel with the magnetic gap b.
In the head, oxygen is diffused from the ferrite substrates 2a and 2b into the ferromagnetic metal thin film 1 at the boundary surface between the ferrite substrates 2a and 2b and the ferromagnetic metal thin film 1, or the ferromagnetic metal thin film 1 is formed.
Diffusion of the element to the ferrite substrates 2a and 2b occurs,
As a result of the interface diffusion layer operating as a pseudo gap, pseudo signal noise is generated, and the SNR of the electromagnetic conversion system is increased.
Deteriorate. To avoid the occurrence of this pseudo-gap, it is proposed to interpose a reaction preventing film 4 as shown in FIG. 11 the ferromagnetic metal thin film 1 and the ferrite substrate 2a, during 2b, a metal such as Pt, SiO ₂ Ya Various reaction preventive films such as oxides such as Al ₂ O ₃ and nitrides such as CrN and SiN have been studied. An example of the conventional method of manufacturing a magnetic head is shown in FIGS.

In FIG. 8, the surfaces of the bar-shaped single crystal ferrite substrates 2a and 2b corresponding to the magnetic gap facing surfaces are mirror-finished by polishing or the like, and the work-affected layers on the surfaces of the substrates 2a and 2b are removed by phosphoric acid etching or the like. Later, a track width regulating groove 5 for determining the track width is formed on the opposing surface by machining using a dicing saw or the like. At this time, the winding groove 6 and the back glass groove 7 for filling the back gap portion with glass are also machined so as to be orthogonal to the track regulating groove 5.

Next, after thoroughly cleaning the substrates 2a and 2b having the track restricting groove 5, the winding groove 6 and the back glass groove 7 formed thereon, as shown in FIG. The reaction prevention film 4 and the ferromagnetic metal thin film 1 are sequentially formed by a sputtering method or the like. As the reaction preventing film 4, a metal thin film such as Pt, an oxide thin film such as SiO ₂ , Al ₂ O ₃ or a nitride thin film such as CrN is used as in FIG. Further, as the ferromagnetic metal thin film, as in FIG. 1, an iron-based nitride alloy film, a Co-based superstructure nitride alloy thin film, a sendust alloy thin film, a Co-based amorphous thin film, or other soft magnetic metal having a higher saturation magnetic flux density than ferrite is used. To use. After that, a gap material for forming a magnetic gap is formed on the surface of the ferromagnetic metal thin film 1 by a sputtering method or the like to form a magnetic core half body.

Then, as shown in FIG. 10, the magnetic core halves are opposed to each other so that a magnetic gap is formed,
After the glass is made to flow into the track width regulating groove 5 to integrally integrate the glass, the magnetic heads are obtained by cutting into each magnetic head.

[0007]

[Problems to be Solved by the Invention] As shown in FIG.
In the conventional parallel type MIG head, the thin reaction preventive film 4 is also present in the track width regulating groove 5, and the reaction preventive film 4 has a thickness of several tens.
The thickness is extremely thin, such as about angstrom, and depending on the material selection and the film thickness, there are cases where sufficient adhesion strength cannot be obtained at the interface between the ferromagnetic metal thin film 1 or the ferrite substrates 2a and 2b. When the magnetic core having the reaction preventing film 4 having a weak adhesion strength is processed into a magnetic head as described above, a step for performing width regulation is performed in the step of step for regulating the width of the sliding surface or the step of tape-polishing the front surface of the head. The ferromagnetic metal thin film 1 and the reaction preventive film 4 are peeled off in the vicinity of the processed surface, and the substrates 2a and 2b and the ferromagnetic metal thin film 1 or the reaction preventive film 4 are removed.
There is a problem that a gap is created between the two and foreign matter tends to be clogged there, and tape powder, etc., may cause demagnetization in the actual operating environment, or may cause dust clogging and head clogging. .

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a magnetic head capable of improving the peeling strength between a substrate and a ferromagnetic metal thin film and improving the manufacturing yield and quality, and a manufacturing method thereof.

[0009]

A magnetic head according to the present invention comprises a pair of magnetic core halves which are joined and integrated so that a magnetic gap is formed. The groove is formed and the ferromagnetic metal thin film is deposited, and the reaction prevention film is interposed between the ferromagnetic metal thin film and the substrate only on the opposing surface of the magnetic gap where the track width regulating groove is not formed. It is what

A method of manufacturing a magnetic head according to the present invention comprises a step of depositing a reaction preventive film on a pair of substrates made of an oxide magnetic material, and a track width regulating groove for determining a track width on the substrate. Forming step, forming a ferromagnetic metal thin film on the substrate to form a pair of magnetic core halves, and joining the pair of magnetic core halves by abutting the ferromagnetic metal thin films to form a magnetic gap The process of integrating
And cutting the integrated magnetic core half into individual magnetic heads.

[0011]

According to the structure of the present invention, in the magnetic head having this structure, since the reaction preventing film is provided at the boundary between the substrate and the ferromagnetic metal thin film facing the gap, no pseudo gap is generated, which is caused by the pseudo signal. Noise can be suppressed. Further, since the reaction preventive film does not exist in the track width regulating groove, diffusion of oxygen in the substrate and diffusion of elements in the ferromagnetic metal thin film occur at the interface between the ferromagnetic metal thin film and the substrate at this portion. Sufficient adhesion strength can be obtained. For this reason,
The peel strength at the boundary surface portion is improved, and peeling does not occur due to a step processing step of regulating the width of the sliding surface, a step of tape polishing the front surface of the head, and the like, so that quality improvement and good manufacturing yield can be realized.

According to the structure of claim 2, in addition to the operation of claim 1, it is possible to easily manufacture a magnetic head having a structure in which the reaction preventing film is interposed only on the gap facing surface of the substrate.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a state in which a pair of magnetic core halves are joined and integrated. Each of the magnetic core halves has a track width regulating groove 5 and a ferromagnetic metal thin film 1 formed on the opposing surfaces of the substrates 2a and 2b made of an oxide magnetic material. As the ferromagnetic metal thin film 1, for example, an iron-based nitride alloy film, a Co-based superstructure nitride alloy thin film, a sendust alloy thin film, a Co-based amorphous thin film, or another soft magnetic metal having a saturation magnetic flux density higher than that of ferrite is used. Further, the reaction prevention film 4 is interposed between the ferromagnetic metal thin film 1 and the substrate 2 only on the opposing surface of the magnetic gap where the track width regulating groove 5 is not formed. As the reaction preventing film 4, a metal thin film such as Pt, an oxide thin film such as SiO ₂ , Al ₂ O ₃ or a nitride thin film such as CrN is desirable. The winding groove 6 and the back glass groove 7 are formed in one magnetic core half body. A magnetic head is obtained by cutting this integrated magnetic core half into individual magnetic heads.

Next, a method of manufacturing this magnetic head will be described. In FIG. 2, the surfaces of the bar-shaped single crystal ferrite substrates 2a and 2b corresponding to the magnetic gap opposing surfaces are mirror-finished by polishing or the like, and the work-affected layer on the ferrite surface is removed by phosphoric acid etching or the like, and then the opposing surfaces are removed. The reaction preventing film 4 made of the above material is formed to a desired thickness by a sputtering method or the like. Since there is a relationship as shown in FIG. 6 between the film thickness of the reaction preventive film 4 and the waviness of the frequency characteristic due to the pseudo gap, the thickness of the reaction preventive film 4 is 1
It is necessary to select about 0 to 100 angstroms.

Next, as shown in FIG. 3, the reaction preventive film 4
The track width regulating groove 5 for determining the track width is formed on the substrates 2a and 2b on which the groove has been formed by machining using a dicing saw or the like. At this time, the winding groove 6 and the back glass groove 7 for filling the back gap portion with glass are also machined so as to be orthogonal to the track regulating groove 5.

Subsequently, as shown in FIG. 4, the opposing surfaces of the substrates 2a and 2b on which the reaction preventing film 4 has already been formed are sufficiently washed, and then the ferromagnetic metal thin film 1 is formed by the sputtering method or the like. The film thickness of the ferromagnetic metal thin film 1 depends on the track width, the thickness of the recording medium used and the coercive force, but is practically about several μm. At this time, since the reaction preventing film 4 has already been applied to the magnetic gap facing surfaces of the substrates 2a and 2b, the substrates 2a and 2b and the ferromagnetic metal thin film 1 directly react with each other at the boundary surface, and the substrate 2a , 2b does not diffuse into the ferromagnetic metal thin film 1 and the elements in the ferromagnetic metal thin film 1 do not diffuse into the substrates 2a and 2b, so that the formation of the pseudo gap is suppressed. However, the track width regulation groove 5
Since the track width regulating groove 5 is processed after forming the reaction preventive film 4, the reaction preventive film 4 does not exist therein. For this reason, reaction between the ferromagnetic metal thin film 1 and the substrates 2a and 2b, oxygen in the substrates 2a and 2b diffuses into the ferromagnetic metal thin film 1, and elements in the ferromagnetic metal thin film 1 are transferred to the substrate 2a. , 2b
Diffusion occurs inside and a stronger bond occurs at the interface.
After that, a gap material for forming a magnetic gap is formed on the surface of the ferromagnetic metal thin film 1 by a sputtering method or the like to form a magnetic core half body.

Next, as shown in FIG. 1, the magnetic core halves are made to face each other so that a magnetic gap is formed, glass is flowed into the track width regulating groove 5 to integrate the glass, and then the chain line is formed. A magnetic head is obtained by cutting each magnetic head as shown in FIG. FIG. 5 is a view of the magnetic head according to the above-described manufacturing method as viewed from the sliding surface. By using this manufacturing method, the adhesion strength of the ferromagnetic metal thin film 1 in the track regulating groove 5 which has been a problem in the past is improved, and the overall manufacturing yield of the magnetic head is improved.

Table 1 is a table comparing the occurrence frequency of film peeling between the conventional magnetic head manufacturing method and the magnetic head manufacturing method of the embodiment of the present invention. In the method of manufacturing the magnetic head according to this embodiment, the peel strength at the boundary surface portion is improved, and a good manufacturing yield can be realized.

[0019]

[Table 1]

[0020]

According to the magnetic head of the present invention, in the magnetic head having this structure, since the reaction preventing film is provided at the boundary surface between the substrate and the gap facing the ferromagnetic metal thin film, the pseudo gap does not occur and the pseudo signal is generated. It is possible to suppress noise caused by. Further, since the reaction preventive film does not exist in the track width regulating groove, diffusion of oxygen in the substrate and diffusion of elements in the ferromagnetic metal thin film occur at the interface between the ferromagnetic metal thin film and the substrate at this portion. Sufficient adhesion strength can be obtained.
Therefore, the peel strength at the boundary surface portion is improved, and peeling does not occur due to the step processing step of regulating the width of the sliding surface or the step of tape-polishing the front surface of the head, improving quality and improving the manufacturing yield. It can be realized and production efficiency can be improved.

According to the method of manufacturing a magnetic head of claim 2, in addition to the effect of claim 1, it is possible to easily manufacture a magnetic head having a structure in which the reaction preventing film is interposed only on the gap facing surface of the substrate.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which a pair of magnetic core halves are joined and integrated in one embodiment of the present invention.

FIG. 2 is an explanatory diagram of a process in which a reaction preventive film is adhered and formed on a substrate.

3 is a process explanatory view in which a track width regulating groove, a winding groove and a back glass groove are formed from the state of FIG.

FIG. 4 is an explanatory view of a process of forming a ferromagnetic metal thin film from the state of FIG.

FIG. 5 is a front view of a sliding surface of a magnetic head according to an embodiment of the present invention.

FIG. 6 is a graph showing the relationship between the film thickness of the reaction preventive film and the waviness of frequency characteristics.

FIG. 7 is a perspective view of a conventional magnetic head.

FIG. 8 is a process explanatory view in which a track width regulating groove, a winding groove and a back glass groove are formed in a conventional example.

9A to 9C are process explanatory views in which a reaction preventing film and a ferromagnetic metal thin film are formed from the state of FIG.

FIG. 10 is a perspective view showing a state in which a pair of magnetic core halves in a conventional example are joined and integrated.

FIG. 11 is a front view of a sliding surface of a conventional magnetic head.

[Explanation of symbols]

 1 ferromagnetic metal thin film 2a, 2b substrate 4 reaction preventive film 5 track width regulating groove

Claims (2)

[Claims] 1. A track width regulating groove is formed on a surface of a pair of magnetic core halves, which are joined and integrated so as to form a magnetic gap, of a substrate made of an oxide magnetic material and facing each other, and a ferromagnetic metal thin film is formed. A magnetic head characterized in that a reaction prevention film is interposed between the ferromagnetic metal thin film and the substrate only on the opposing surface of the magnetic gap which is formed by deposition and in which the track width regulating groove is not formed. 2. A step of depositing a reaction preventive film on a pair of substrates made of an oxide magnetic material, a step of forming a track width regulating groove for determining a track width on the substrate, and the substrate. Forming a pair of magnetic core halves by forming a ferromagnetic metal thin film thereon, and joining and joining the pair of magnetic core halves by abutting the ferromagnetic metal thin films to form a magnetic gap. And a step of cutting the integrated magnetic core half into individual magnetic heads.