JPH06274813A - Method of manufacturing magnetic head - Google Patents

Abstract

(57) [Summary] [Object] To provide a manufacturing method of a magnetic head having good reproduction efficiency and small variation by removing a processing strain and an altered layer induced in a core material by machining. [Structure] In the manufacturing process of the magnetic head, cutting, cutting,
After completion of a machining process such as polishing, the machined surface is subjected to ion beam etching. [Effect] In the magnetic head manufacturing process, the so-called work-affected layer in which the work strain and the contamination layer are induced by the machining such as the head chip cutting process is removed by the ion beam etching method. As a result, it is possible to obtain a magnetic head having a good reproduction efficiency and a small variation, without substantially changing the conventional magnetic head manufacturing method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a magnetic head such as a VTR, and more particularly to a method for manufacturing a magnetic head having good reproduction efficiency.

[0002]

2. Description of the Related Art Conventionally, bulk magnetic materials such as single crystal ferrite have been mainly used for magnetic heads used in VTRs and the like. FIG. 11 shows a ferrite head described in JP-A-56-68914. Figure 11
In, the core pieces 3 and 3 ′ are made of MnZn ferrite or the like, and are joined to the working gap shown by 5 through the gap material such as SiO ₂ by the filled glass shown by 4 and 4 ′. Reference numeral 6 is a window for winding the signal coil. The manufacturing process will be described below.

First, as shown in FIG. 12, core blocks 11 and 11 'having a predetermined shape in which a window 13 for a winding is formed are made of MnZn ferrite or the like, and the core blocks 11 and 11' are formed on the respective gap abutting surfaces. After forming the groove 12 that regulates the track width t in the direction perpendicular to the longitudinal direction of the above and mirror-polishing the gap abutting surface, the pair of core blocks 11 and 11 'are joined and integrated by glass fusion, Obtain the core block 14. Next, the core block 14 is cut along the vertical plane indicated by the alternate long and short dash line in FIG. 13 to obtain a head chip as shown in FIG.

The above process is a method generally used for manufacturing a magnetic head, and the manufacturing process for other magnetic heads is also similar to the manufacturing method shown in FIGS.

[0005]

In the conventional manufacturing method,
Machining strain is induced in the core material when performing machining such as the process of forming the groove that regulates the track width, the process of forming the winding window groove, the process of cutting out the magnetic head chip, and the process of mirror polishing the gap abutting surface. However, there is a problem in that the magnetic permeability of the magnetic core is reduced due to the inverse magnetostriction effect, the performance of the magnetic head is degraded, and its variation is increased. This situation is particularly remarkable in a magnetic head using a single crystal ferrite having a large magnetostriction constant, which has been a serious problem. Further, also in a magnetic head having a main magnetic path formed of a metal magnetic material, an altered layer is generated in the metal magnetic material due to contamination due to machining, resulting in deterioration of the performance of the magnetic head and an increase in its variation width. There was such a problem.

According to the present invention, the work-affected layer is removed without changing the conventional manufacturing method, and the magnetic core has a high magnetic permeability, and thus has a good reproducing efficiency and a small variation width. The purpose is to provide a method.

[0007]

According to the present invention, a processing strain caused by machining in a conventional manufacturing method,
Also, attention was paid to contamination on the processed surface, and countermeasures were taken.

That is, in the method of manufacturing a magnetic head of the present invention, a so-called work-affected layer in which a working strain and a contamination layer are induced by machining is removed by an ion beam etching method.

[0009]

The work-affected layer formed on the magnetic core by the mechanical work is removed by etching the work surface with an ion beam, and the decrease in the magnetic permeability of the magnetic core can be prevented. As a result, it is possible to obtain a magnetic head with less variation in performance and good reproduction efficiency. According to the method of manufacturing a magnetic head of the present invention, it is possible to obtain a magnetic head having a small variation in performance and excellent performance, with almost no change in the conventional manufacturing method.

[0010]

EXAMPLES The present invention will be described below with reference to examples.

(First Embodiment) FIG. 2 shows a ferrite head to which the present invention is applied. In FIG. 2, the core piece 3,
3'is made of single crystal ferrite, and is joined to the working gap shown by 5 via a gap material such as SiO ₂ by the filled glass shown by 4, 4 '. Reference numeral 6 is a window for winding the signal coil. The upper surface a of the ferrite head shown in FIG. 2 is a sliding surface with the magnetic tape. As shown in FIG. 2, the sliding width w1 is smaller than the width w2 on the rear side, which improves the contact state between the magnetic tape and the magnetic head.
In addition, the regeneration efficiency and chip strength are secured.

A method of manufacturing this ferrite head will be described below.

(First Step) As shown in FIG. 4, a core piece 11 made of ferrite is prepared, and a track width regulating groove 12 is formed in the core piece 11 by dicing or the like. When forming this groove, the front 11a side is inclined upward by an appropriate angle, and the track width regulating groove 12 is cut so as to gradually become shallower from the front 11a side toward the rear 11b side.

(Second step) As shown in FIG. 5, the core piece 1
First, the winding window groove 13 is cut in a direction parallel to the surface a which is a sliding surface with respect to the magnetic medium.

(Third step) The core gap piece 11 formed by the first step and the core gap piece 11 'formed by the second step are mirror-finished on the surfaces facing the operating gap.

[0016] (fourth step) core piece 11 and 11 made by the third step ', the working gap facing surfaces is faced each other via a gap material such as SiO _2, as shown in FIG. 6, a glass melting The core piece 14 is joined and integrated by wearing.
To get

(Fifth step) As shown in FIG. 7, a groove 15 for narrowing the sliding width is formed on the core piece 14 formed in the third step by dicing or the like in a direction perpendicular to the gap abutting surface.
To a predetermined depth d.

(Sixth Step) After the sliding surface of the core piece 14 obtained by the fourth step with the magnetic medium is rounded, a surface perpendicular to the gap abutting surface, that is, ghij surface or g ′ in FIG. A head chip is obtained by cutting along the h'i'j 'plane.

(Seventh step) The side face b of the ferrite head chip 2 shown in FIG. 2 is placed on the tray 1 as shown in FIG. 1, and the side face b is etched by, for example, an Ar ion beam. Next, the ferrite head chip 2
The other side surface b is arranged on the tray 1 as shown in FIG. 1, and the side surface c is etched by, for example, an Ar ion beam.

According to the above method, it is possible to remove the processing strain generated in the ferrite by the mechanical processing, with almost no change in the conventional method of manufacturing the magnetic head.

With respect to the ferrite head thus obtained, the sliding surface was subjected to circular polishing to obtain a predetermined gap depth, the signal coil was wound for a predetermined number of turns, and the reproduction output was measured. The relationship between the variation width of the reproduction output and that of the reproduction output is as shown in FIG. The reproduction output is improved as the etching amount is increased, and is saturated when the etching amount is 1 μm or more. Further, the variation width of the reproduction output of the conventional head not subjected to etching by Ar ion beam is about 3 dB.
On the contrary, the variation width of the ferrite head according to the present invention which was etched by Ar ion beam was about 1 dB. Further, the average value of the reproduction output of the ferrite head according to the present invention was about 1.5 dB higher than that of the conventional ferrite head.

As described above, the ferrite head manufactured by applying the manufacturing method of the present invention is better than the ferrite head obtained by the conventional manufacturing method.

(Second Embodiment) A method of manufacturing a ferrite head as shown in FIG. 2 was introduced in the first embodiment. The core pieces 11 and 11 'produced by the third step in this manufacturing method are arranged on the tray 1 as shown in FIG.
The e-plane of 1 and the f-plane of the core piece 11 'are etched by, for example, an Ar ion beam. After this, the fourth to sixth steps in the method of manufacturing the magnetic head introduced in the first embodiment are performed. According to the above-described method, similarly to the first and second embodiments, it is possible to remove the processing strain generated in the ferrite by machining without changing the conventional magnetic head manufacturing method, and the core portion can be further removed. Pieces 11 and 11 '
It is possible to eliminate the processing strain that occurs on the mating surfaces of.

With respect to the head thus obtained, the sliding surface was also rounded to obtain a predetermined gap depth, the signal coil was wound for a predetermined number of turns, and the reproduction output was measured. A good head could be obtained as in the first embodiment.

(Third Embodiment) FIG. 3 is an external perspective view of a composite head of ferrite and a metal magnetic film to which the present invention is applied. In FIG. 3, the core pieces 3 and 3'are made of ferrite and are joined to the working gap shown by 5 through a gap material such as SiO ₂ by the filled glass shown by 4 and 4 '. Reference numeral 6 is a window for winding the signal coil. Reference numeral 7 is a metal magnetic film such as CoNbZr. Also for a composite type head of ferrite and a metal magnetic film as shown in FIG.
Etching by Ar ion beam was performed as in the second embodiment. According to the above method, it is possible to remove the processing strain generated in ferrite by mechanical processing and the contamination layer generated in the metal magnetic material of the gap abutting surface by the mirror polishing step without changing the conventional magnetic head manufacturing method. it can.

With respect to the head thus obtained, the sliding surface was subjected to circular polishing to obtain a predetermined gap depth, the signal coil was wound for a predetermined number of turns, and the reproduction output was measured. A good head could be obtained as in the first and second embodiments.

(Fourth Embodiment) The present invention can be applied to a magnetic head whose main magnetic path is made of a magnetic metal material.
That is, in the manufacturing process of the magnetic head, similarly to the second embodiment, after the mirror-polishing process of the gap abutting surface, the gap abutting surface is etched by the Ar ion beam. This makes it possible to remove the contaminated layer generated in the metallic magnetic material.

With respect to the head thus obtained, the sliding surface was also rounded to obtain a predetermined gap depth, the signal coil was wound for a predetermined number of turns, and the reproduction output was measured. It was possible to obtain a good head as in the first, second, and third embodiments.

Although Ar ions are used as the ion beam in the first, second, third, and fourth embodiments described above, Ar + O ₂ or the like may be used instead of Ar ions.

In addition to the heads described in the first, third, and fourth embodiments, the present invention also employs various ferrite heads, various composite heads made of ferrite and a metallic magnetic material, and metallic magnets. It can be applied to various head manufacturing methods using a material as a main magnetic path.

[0031]

As described above, according to the present invention, a so-called work-affected layer in which a working strain and a contaminated layer are induced by machining is induced is removed by an ion beam etching method. A magnetic head with good reproduction efficiency can be obtained. Further, according to the present invention, a good magnetic head can be obtained with almost no modification of the conventional method of manufacturing a magnetic head.

[Brief description of drawings]

FIG. 1 is an external perspective view showing a step of subjecting a head chip to ion beam etching in a first embodiment of a method of manufacturing a magnetic head according to the present invention.

FIG. 2 is an external perspective view showing a ferrite head to which the present invention is applied.

FIG. 3 is an external perspective view showing an example of a composite head of ferrite and a magnetic metal material.

FIG. 4 is an external perspective view showing a step of inserting a track width regulating groove into a ferrite substrate in a method of manufacturing a ferrite head to which the present invention is applied.

FIG. 5 is an external perspective view showing a step of inserting a winding groove.

FIG. 6 is an external perspective view showing a step of joining the left and right cores.

FIG. 7 is an external perspective view showing a step of narrowing the sliding width.

FIG. 8 is an external perspective view showing a head chip cutting step.

FIG. 9 is an external perspective view showing a step of performing ion beam etching on the core block in the third embodiment of the magnetic head manufacturing method according to the present invention.

FIG. 10 is a graph showing a relationship between an ion beam etching amount of a ferrite head and a reproduction output variation width according to a method of manufacturing a magnetic head of the present invention.

FIG. 11 is an external perspective view showing an example of a conventional ferrite head.

FIG. 12 is an external perspective view showing a step of joining the left and right cores in the conventional magnetic head manufacturing step.

FIG. 13 is an external perspective view showing a head chip cutting step in the conventional magnetic head manufacturing step.

[Explanation of symbols]

1 ... Tray, 2 ... Head chip, 3, 3 ', 11, 1
1 ', 14 ... Core piece, 5 ... Working gap, 6 ... Coil winding window, 7 ... Metal magnetic film.

Claims (4)

[Claims] 1. A method of manufacturing a magnetic head having a main magnetic path formed of magnetic ferrite, wherein the manufacturing step of the magnetic head is completed by an ion beam on the machined surface after completion of machining steps such as cutting, cutting and polishing. A method of manufacturing a magnetic head, comprising a step of performing etching. 2. The method of manufacturing a magnetic head according to claim 1, wherein the machining is a chip cutting step, and the side surface of the head chip is subjected to ion beam etching. 3. A method of manufacturing a magnetic head according to claim 1, wherein the main magnetic path of the magnetic head is made of magnetic ferrite and a metal magnetic material. 4. A method of manufacturing a magnetic head according to claim 1, wherein a main magnetic path of the magnetic head is made of a magnetic metal material.