JPH0636218A - Magnetic head and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a magnetic head wherein a sliding noise is low, the head is excellent in wear resistance and the head can comply with a high-coercive- force recording medium. CONSTITUTION:In a magnetic head, a metal magnetic film 12 is formed in a recording track part on a ferrite 11a, by using a gap 15 as a boundary, on recording-medium opposite faces of ferrites 11a, 11b deposited by glasses 14a, 14b, a recording track part on the ferrite 11b is formed of the metal magnetic film 12 and of a metal oxide, and nonmagnetic ceramics 13a, 13b are formed on both sides of the recording track parts. The magnetic head is excellent in wear resistance, its rubbing noise is low and it is provided with excellent recording and reproduction performance with reference to a high-coercive-force recording medium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head suitable for use in a floppy disk device for recording and reproducing various kinds of information such as data, images and sounds, a video tape recorder (hereinafter referred to as VTR) and the like. The present invention relates to a manufacturing method thereof.

[0002]

2. Description of the Related Art FIG. 11 shows, for example, JP-A-60-9570.
FIG. 7 is a perspective view of a conventional magnetic head shown in Japanese Patent Publication No. 4).
In FIG. 11, 1 is ferrite such as Mn-Zn and Ni-Zn, 2 is sendust (Fe-Al-Si),
Permalloy (Fe-Ni), amorphous (Co type, F
(e) Metallic magnetic thin film made of alloy or the like, 4 is glass filled in the groove for track width regulation, and 5 is a gap for recording and reproduction.

In the conventional magnetic head having such a structure, in order to realize a magnetic head having excellent recording and reproducing characteristics with respect to a high coercive force medium, a gap is generated in order to generate a strong magnetic field in the gap. In the vicinity of 5, a metal magnetic film 2 having a saturation magnetic flux density higher than that of the ferrite 1 is formed as a thin film.

The first characteristic of this magnetic head lies in its processing process. That is, first, a ferrite 1 processed into a desired shape is prepared, and a metal magnetic film 2 is thinly formed on the ferrite 1, and then a glass 4 is formed.
The point is to move to the filling process.

The second characteristic is the structure of the tape sliding surface, in which only a small portion near the gap 5 is composed of the metal magnetic film 2 and the glass 4, and most of it is composed of the ferrite 1. That is the point.

[0006]

In the conventional magnetic head as described above, the glass 4 having a melting point of about 200 to 300 ° C. lower than the glass having a high melting point used for the magnetic head is used due to the restriction of the processing process. However, there is a problem that the manufacturing yield is remarkably deteriorated due to a decrease in the mechanical strength of the magnetic head.

Further, since most of the sliding surface is made of ferrite 1, the abrasion resistance is excellent, but there is a problem that sliding noise is high.

The present invention has been made to solve the above problems, and has wear resistance equal to or higher than that of a ferrite head, lower sliding noise than that of a ferrite head, and suitable for a medium having high coercive force. The purpose of the present invention is to obtain a magnetic head having excellent recording and reproducing performances. Further, the manufacturing yield can be improved, the manufacturing process is simple, and a magnetic head having a high recording density compatible with a high coercive force medium can be manufactured at low cost. An object of the present invention is to provide a method of manufacturing a magnetic head capable of manufacturing the magnetic head.

[0009]

SUMMARY OF THE INVENTION A magnetic head according to the present invention comprises a core half body pair made of a ferromagnetic metal oxide film integrally welded with a non-magnetic filling, and a core half body pair having a gap as a boundary. A recording track portion formed of a metal magnetic film on the recording medium contact surface side of one of the core halves, and the metal magnetic film and the metal oxide film on the recording medium contact surface side of the other core half. The formed recording track portion is provided.

As a method of manufacturing the magnetic head of the present invention, a ferromagnetic metal oxide is provided on the recording medium contact surface side of the core half body pair made of a ferromagnetic metal oxide film integrally welded with a non-magnetic filler. Forming a metal magnetic film with a higher saturation magnetic flux density,
A gap material is formed in the gap portion of the pair of core halves, and a non-magnetic ceramic is formed on both sides of the recording track portion of the pair of core halves.

[0011]

In the magnetic head constructed as described above, only the portion corresponding to the track width of the recording track portion is the metal magnetic film on the recording medium facing surface side of the core half body pair, and most of the rest is non-magnetic. By using ceramic, the exposed portion of the core half pair on the contact surface side of the recording medium becomes small or nonexistent, and sliding noise is suppressed, and the non-magnetic ceramic prevents the sliding surface portion from the contact surface side of the recording medium. By occupying the most part, it improves the wear resistance.

In the method of manufacturing the magnetic head,
The high melting point non-magnetic filler can be used by the steps of sequentially forming the metal magnetic film and the non-magnetic ceramic, the mechanical strength is increased, the manufacturing process is simplified, and the manufacturing yield is improved. .

[0013]

【Example】

Example 1. FIG. 1 is a perspective view showing an embodiment of a magnetic head of the present invention. In FIG. 1, 11a and 11b are ferromagnetic metal oxides represented by Mn-Zn and Ni-Zn, respectively, and have a high transparency. Magnetic susceptibility single crystal and polycrystalline ferrite (hereinafter, simply referred to as ferrite). Each of the ferrites 11a and 11b forms a core half body, and both of them form a core half body pair.

Further, 12 is sendust (Fe-Al-Si) having a higher saturation magnetic flux density than the ferrites 11a and 11b,
Permalloy (Fe-Ni), amorphous (Fe-based, C
o)), metal magnetic films such as alloys, 13a and 13b are high-hardness non-magnetic ceramics such as barium tannate and calcium titanate, and 14a and 14b are ferrites 11a and 11
Reference numeral 15 is a non-magnetic filling material such as lead-based glass for integrally welding b, and 15 is a gap for operating the magnetic head.

FIG. 2 is an enlarged cross-sectional view of the gap portion cut along the line AA of FIG. In this FIG.
The same parts as those in FIG. 1 are designated by the same reference numerals. When a magnetic head is actually used, the side where the metal magnetic film 12 of FIG. 2 is located is arranged on the side where the recording medium such as a disk or tape flows out. This is because the recording magnetization in the recording medium due to the head magnetic field strongly depends on the gap magnetic field on the recording medium outflow side.

Next, a method of manufacturing the magnetic head of the present invention will be described with reference to FIGS. First, FIG. 3 and FIG. 4 are perspective views showing a ferrite piece which is a base of a constituent member of a pair of core halves of a magnetic head. Figure 3
Shows the ferrite piece 11a1 of the ferrite 11a, and FIG. 4 shows the ferrite piece 11b of the ferrite 11b.
1 is shown.

These ferrite pieces 11a1 and 11
Both b1 are finished to a predetermined size by grinding, lapping or the like. Particularly, the gap surface and the surface on which the thin metal magnetic film 12 is formed are mirror-finished without processing distortion. In addition, each ferrite piece 11a1, 11b1
The width dimensions H1 and H2 of are set to H2> H1.

Next, as shown in FIG. 5, the glass piece 11a2 and the winding window 11a3 are processed in the ferrite piece 11a1, and the glass piece 11b2 is processed in the ferrite piece 11b1 as shown in FIG. To do. These processes are performed by, for example, grinding using a diamond wheel. Regarding the processing of the winding window 11a3, the winding window 11a3 may be provided only on the ferrite piece 11b1 or on both ferrite pieces 11a1 and 11b1.

After that, although not shown here, SiO ₂ , Al ₂ O is formed on the processed surface of the glass groove 11a2 of the ferrite piece 11a1, the winding window 11a3 and the glass groove 11b2 of the ferrite piece 11b1. A non-magnetic member having a high melting point such as _{3 is} formed into a thin film by sputtering and ion plating. It is desirable that the film thickness is approximately the same as that of the gap material described later.

Next, the glass bonding process shown in FIG. 7 is started. The ferrite piece 11a1 of FIG. 5 and FIG.
As shown in FIG. 7, the ferrite piece 11b1 of
Although not shown, a glass rod is inserted into the glass grooves 11a2 and 11b2 and the winding window 11a3 by joining the processed surfaces to raise the temperature, and both ferrite pieces 11a1 and 11b are heated.
1 is fused and integrated.

In this case, in a conventional composite magnetic head composed of a metal magnetic film and ferrite, a glass having a low melting point of about 600 ° C. or lower is used to prevent the film from peeling due to thermal stress during glass bonding. To be In particular, when an amorphous magnetic film is used, there is a restriction on the crystallization temperature, and glass of 500 ° C. or lower is used.
In the magnetic head of the present invention, a non-magnetic filling material such as glass at 700 ° C. to 900 ° C. used in a ferrite head is used. Lead-based glass is used for the magnetic head, and the higher the working temperature of this glass, the better the mechanical properties.

After the above-mentioned glass bonding, groove processing for track width regulation shown in FIG. 8 is performed. This FIG. 8 shows ferrite pieces 11a1 and 11b integrated by glass fusion.
FIG. 1 is a perspective view showing a state in which the grooved surface of No. 1 is on the upper side.
The track width regulating groove 11a4 is formed in the ferrite piece 11a1 and the track width regulating groove 11b3 is also formed in the ferrite piece 11b1 by using the same machining method as the machining of 1a2, 11b2 and the winding window 11a3.

These track width regulating grooves 11a4, 11
The depth D of b3 is formed to be deeper than the gap depth Gd shown in the enlarged cross-sectional view of the gap portion in FIG.

After this, although not shown, from the SiO ₂ and Al ₂ O ₃ etc. corresponding to the gap length formed in the exposed portion of the gap surface of height h with respect to the ferrite piece 11a1 of the ferrite piece 11b1 of FIG. Since the non-magnetic film is cracked or partially peeled due to thermal stress during glass bonding, it is removed by chemical or physical etching.

After removing the non-magnetic film, a mask is applied to the surface on which the thin metal magnetic film is formed, and a new non-magnetic film of SiO ₂ , Al ₂ O ₃ or the like having a thickness corresponding to the gap length is deposited, sputtered, or ion-deposited. A gap material is formed by forming a thin film by plating or the like.

After forming the gap material, as shown in FIG. 9, the metal magnetic thin film 12 and the non-magnetic ceramic 13a,
The process proceeds to the film forming process of 13b. 9 is a side view of FIG. 8 and shows a state in which the metal magnetic thin film 12 and the nonmagnetic ceramics 13a and 13b (13b is not shown in FIG. 9) are sequentially formed.

Next, the nonmagnetic ceramics 13a, 13
When the film forming step of b is completed, as shown in FIG. 10, the ferrite piece disk and the recording medium contact surface such as data are lapped. Wrapping amount is 1 winding window
The metal magnetic film 12 of the ferrite piece 11a1 on the 1a3 side
Keep it to the extent that it will not be ground.

After that, if cutting is performed along the cutting lines B and C in FIG. 10, the magnetic head of the present invention as shown in FIG. 1 is obtained. When the height h shown in FIG. 8 is larger than the film thickness of the metal magnetic film 12, the magnetic head of the present invention shown in FIG. 1 is obtained, and the height h shown in FIG.
When the film thickness is smaller than 2, the magnetic head shown in FIG. 11 is obtained.

Since ferrite is superior to the metal magnetic film 12 in wear resistance, when the wear resistance is prioritized, the magnetic head of FIG. 1 is used and the recording performance and the sliding noise characteristic are prioritized. In this case, the height h in FIG.
A magnetic head having a thickness smaller than 2 may be used.

[0030]

Since the present invention is constructed as described above, it has the following effects.

A recording formed by a metal magnetic film on the contact surface side of the recording medium with one core half of a core half composed of a ferromagnetic metal oxide film integrally welded with a non-magnetic filling material as a gap. By forming a recording track part with a metal magnetic film and a metal oxide film on the contact surface side of the track part and the other half of the recording medium, and by providing a non-magnetic ceramic on both sides of the recording track part, the conventional metal magnetic Compared to a magnetic head that uses a film, the ferrite surface on the sliding surface side is minimal or absent, sliding noise is extremely low, and a high hardness non-magnetic ceramic is used for most of the sliding surface side. , Wear resistance is equal to or higher than that of ferrite head.

As a method of manufacturing a magnetic head, a metal magnetic film having a saturation magnetic flux density higher than that of a ferromagnetic metal oxide is formed on the contact surface side of a recording medium of a pair of ferromagnetic core halves integrally welded with a nonmagnetic filler. The high melting point non-magnetic filler can be used by forming a gap material in the gap part of the core half pair and depositing the non-magnetic ceramic on both sides of the recording track part of the core half pair. In addition, the mechanical strength is high, the manufacturing yield is good, and the head with high recording density corresponding to the recording medium with high coercive force can be manufactured at low cost by a simple manufacturing process.

[Brief description of drawings]

FIG. 1 is a perspective view of a magnetic head according to a first embodiment of the invention.

FIG. 2 is an enlarged cross-sectional view of a gap portion shown by cutting along the line AA in FIG.

FIG. 3 is a perspective view of one ferrite piece applied to the method of manufacturing a magnetic head of the present invention.

FIG. 4 is a perspective view of another ferrite piece applied to the above manufacturing method.

5 is a perspective view for explaining a step of processing a glass groove and a winding groove in the ferrite piece of FIG.

FIG. 6 is a perspective view for explaining a step of processing a glass groove in the ferrite piece of FIG.

7 is a front view for explaining a glass welding process of the ferrite piece of FIG. 5 and the ferrite piece of FIG.

FIG. 8 is a perspective view of a pair of core halves for explaining a process of processing a track width regulating groove in the manufacturing method of the above.

FIG. 9 is a side view of a ferrite piece for explaining a film forming process of a metal magnetic film and a non-magnetic ceramic in the above manufacturing method.

FIG. 10 is a side view for explaining the steps of grinding, polishing, and cutting the head chip of the non-magnetic ceramic in the above manufacturing method.

FIG. 11 is a perspective view of a conventional magnetic head.

[Explanation of symbols]

 11a ferrite 11b ferrite 11a1 ferrite piece 11a2 glass groove 11a3 winding window 11a4 track width regulating groove 11b1 ferrite piece 11b2 glass groove 11b3 regulating groove 12 metal magnetic film 13a non-magnetic ceramic 13b non-magnetic ceramic 14a glass 14b glass 15 gap

Claims (2)

[Claims] 1. A pair of core halves made of a ferromagnetic metal oxide fused with a pair of non-magnetic fillers, and one of the pair of core halves at a recording medium contact surface side with a gap as a boundary. A recording track portion formed of a metal magnetic film on the core half body, and a recording track portion formed of the metal magnetic film and a metal compound on the other core half body on the recording medium contact surface side. A magnetic head comprising: a non-magnetic ceramic formed on both sides of each of the recording track portions of the surface of the pair of core halves facing the recording medium; and a gap material formed at a portion of the gap. 2. A metal magnetic film having a saturation magnetic flux density higher than that of a ferromagnetic metal oxide is formed on an upper surface of a pair of core halves made of a ferromagnetic metal oxide which are integrally welded with a non-magnetic filling and which is in contact with a recording medium. And forming a gap material at the gap portion of the pair of core halves on the contact surface side of the recording medium, and forming a non-magnetic ceramic on both sides of the recording track portion on the contact surface of the recording medium of the pair of core halves. A method of manufacturing a magnetic head, which comprises forming a film.