JPH05298616A - Magnetic head and its manufacture - Google Patents

Abstract

PURPOSE:To prevent magnetic mutual interference between core chips and to obtain stable recording and reproducing characteristics. CONSTITUTION:The magnetic head is constituted by arranging core chips 12 for low recording density and high recording density, which are formed by integrally joining cores made of ferromagnetic bodies such as ferrite, and have magnetic gaps g1, gu1', and g2 formed on their medium slide surface 10 and correspond to different recording density, opposite each other in parallel at a specific interval; and a thin shield film 12 formed of a metallic magnetic body such as 'Sendust(R)' sandwiched between 1st and 2nd nonmagnetic bodies 14 and 15 is arranged between both the core chips 1 and 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head and a method of manufacturing the same, and more specifically, it is used in an FDD (floppy disk drive) device and has a plurality of recording densities, for example, a low recording density and a high recording density. A magnetic head in which two core chips are integrated.

[0002]

2. Description of the Related Art A magnetic head used in an FDD device is
There is one that integrates two core chips with different recording densities. This is a single FDD for writing and reading information to and from a floppy disk, which is a recording medium, at a normal low recording density of 1 to 2 megabytes and at a high recording density of 10 to 12 megabytes. This is a device that can be used for both.

A conventional example of a magnetic head in which two core chips having different recording densities are integrated will be described below with reference to FIGS. 10 to 13.

In FIGS. 10 and 11, (1) is a lead /
A tunnel erase type low recording density core chip having two magnetic gaps, a write gap g ₁ and an erase gap g ₁ ′ (hereinafter, referred to as “first core chip”), and a pair of cores made of ferromagnetic ferrite are joined together. The read / write gap g ₁ and the erase gap g ₁ ′ are integrally formed on the top surface thereof. Although not shown, a closed magnetic circuit is formed by mounting a coil formed by winding a wire on a bobbin under the first core chip (1) and then fixing the back core by bridging.

(2) is one read / write gap g ₂
In a MIG [Metal In Gap] type high recording density core chip [hereinafter referred to as a second core chip], a pair of cores made of ferromagnetic ferrite are joined and integrated, and a read / write gap is formed on the top end face thereof. g ₂ is formed, and a metal magnetic film (3) such as sendust having a high saturation magnetic flux density is arranged in the vicinity of the read / write gap g ₂ .
Although not shown, as in the case of the first core chip (1), a coil formed by winding a wire around a bobbin is attached to the lower part of the second core chip (2), and then the back core is fixed by bridging. A closed magnetic circuit is formed.

(4) and (5) are sliders made of a non-magnetic ceramic adhered and fixed to the outside of the first and second core chips (1) and (2). The write gap g ₁ and the erase gap g ₁ ′ and the read / write gap g ₂ of the second core chip (2) are protected from the outside. Further, (6) is a slider adhered and fixed to the inner sides of the first and second core chips (1) and (2), and a shield plate (7) made of ferromagnetic ferrite is provided on both sides with a non-magnetic material. It has a structure sandwiched between ceramic plates (8) and (9). This shield plate (7) is the first
And the second core chips (1) and (2) are arranged between the read / write gaps g ₁ and g ₂ to prevent leakage of magnetic flux at both read / write gaps g ₁ and g ₂ during recording and reproduction of information. The magnetic mutual interference due to is blocked to prevent the deterioration of characteristics.

The first and second core chips (1) and (2) are integrated with the sliders (4), (5) and (6) in a state where they are arranged in parallel to each other in the medium running direction, and their top ends are integrated. A medium sliding contact surface (10) is formed on the surface. The medium sliding surface (10) is provided with an air bleeding groove (11) near the first core chip (1) along the medium running direction to maintain the medium sliding contact state well. There is. When low density recording is performed by sliding the floppy disk on the medium sliding contact surface (10) thus formed, the read / write gap g ₁ and the erase of the first core chip (1) are erased. Information is written and read with the gap g ₁ ′, and when high density recording is performed, information is written and read with the read / write gap g ₂ of the second core chip (2).

[0008]

By the way, as described above, at the time of recording and reproducing information, magnetic interference due to leakage of magnetic flux in both the read / write gaps g ₁ and g ₂ is blocked. Lead of the second core chip (1) (2) /
A shield plate (7) is arranged between the write gaps g ₁ and g ₂ .

However, for example, when writing information on the floppy disk by the read / write gap g ₂ of the second core chip (2), as shown in FIG. 11, the second core chip (2) to the first core chip (2) The magnetic flux trying to interfere toward 1) is once absorbed by the shield plate (7),
Since the magnetic flux that has passed through the shield plate (7) returns to the second core chip (2) again, the above-mentioned second
However, there is a problem that the leakage flux in the read / write gap g ₂ of the core chip (2) is reduced and the overwrite characteristic is deteriorated.

This can be suppressed by making the shield plate (7) thinner, but making the shield plate (7) thinner makes the slider (6) including the shield plate (7) thinner. It was very difficult to make. That is,
The slider (6) is manufactured by sticking a shield plate (7) sandwiched between two non-magnetic ceramic plates (8) and (9) as shown in FIG. Therefore, it is very difficult to attach the thin shield plate (7) to the ceramic plates (8) and (9), and the distance between the first and second core chips (1) and (2) is about 0.3 mm in the past. The current situation was that there was no choice but to do so.

As a result, when the magnetic head is mounted on the FDD device as shown in FIG. 13 [in the figure, two magnetic heads are provided above and below the medium (m) so that recording and reproduction can be performed on both sides of the medium (m). Is arranged], the distance between the first and second core chips (1) and (2) is large, so that the medium sliding contact surface (10)
However, the contact area between the medium (m) and the gaps g ₁ and g ₂ becomes unstable and it is difficult to obtain good recording and reproducing characteristics.

Therefore, the present invention has been proposed in view of the above problems, and an object thereof is to prevent magnetic mutual interference between core chips and to obtain a stable recording / reproducing characteristic. It is to provide a head and a manufacturing method thereof.

[0013]

As a technical means for achieving the above object, in a magnetic head according to the present invention, a core made of a ferromagnetic material is joined and integrated, and a magnetic gap is formed on the medium sliding contact surface. In a magnetic head in which a plurality of formed core chips corresponding to different recording densities are arranged in parallel and opposed to each other at a predetermined interval, a metal magnetic body sandwiched by first and second non-magnetic bodies is provided between the core chips. It is characterized in that a thin film-shaped shield film is formed.

In the above magnetic head, the shield film may be linear, sawtooth or wavy along the medium running direction, or a plurality of shield films may be arranged between core chips, or
It is desirable that the length of the shield film along the medium running direction be equal to or less than the length of the core chip along the medium running direction.

Further, in the method of manufacturing a magnetic head according to the present invention, a plurality of core chips corresponding to different recording densities in which cores made of a ferromagnetic material are joined and integrated and a magnetic gap is formed on the medium sliding contact surface are provided. The manufacturing process and the first non-magnetic material plate is coated with a metal magnetic material to form a thin shield film, and the second non-magnetic material is deposited thereon to form a thin plate slider. The method is characterized by including a manufacturing step and a step of integrally disposing the core chip and the slider by interposing the core chips in parallel at a predetermined interval and interposing a slider therebetween.

[0016]

In the magnetic head of the present invention, between the core chips,
By arranging a thin shield film made of a metal magnetic material, the leakage of magnetic flux from one core chip to the other core chip is absorbed by the shield film during recording and reproduction of information, and the absorbed magnetic flux is shielded. Since the film is thin, it can be reduced, and the reduction of the leakage of the magnetic flux in the magnetic gap can be suppressed as much as possible to stabilize the recording / reproducing characteristics.

In the method of manufacturing a magnetic head according to the present invention, the thin shield film is formed between the core chips by forming the thin shield film by depositing the metal magnetic material on the first non-magnetic material plate. -Shaped slider can be easily manufactured, the distance between core chips can be made as small as possible without impairing the shield effect, and the medium sliding contact surface can be reduced,
It is possible to stabilize the contact state between the medium and the magnetic gap.

[0018]

Embodiments of a magnetic head and a method of manufacturing the same according to the present invention will be described with reference to FIGS. The same parts as those in FIGS. 10 to 13 are designated by the same reference numerals, and the duplicated description will be omitted.

A feature of the present invention is that a thin film shield film (12) made of a magnetic metal material such as sendust is arranged between the first and second core chips (1) and (2).

Shield film (12) in the embodiment shown in FIG.
Is a linear shape along the medium running direction as shown in the figure, and the slider (13) including the shield film (12) is manufactured as follows. That is, as shown in FIGS. 2A to 2C, the first non-magnetic plate (1
4) A thin magnetic shield film (12) is formed by depositing a metallic magnetic material such as sendust by sputtering or vapor deposition, and a second non-magnetic material plate (15) made of ceramic or the like is formed thereon. A thin slider (13) is obtained by adhesive fixing. Then, the slider (13) is bonded and fixed while being sandwiched between the first and second core chips (1) and (2). Instead of adhering and fixing the second non-magnetic material plate (15), it is also possible to perform glass molding as described later.

In the magnetic head of this embodiment, the first and second magnetic heads
Thin film shield film (12) between core chips (1) (2)
Since it is arranged, when recording and reproducing information, for example, the second
When writing information to the floppy disk by the read / write gap g ₂ of the core chip (2), the second core chip (2) to the first core chip (1) as shown in FIG.
The magnetic flux attempting to interfere with the magnetic field is once absorbed by the shield film (12), and the magnetic flux passing through the shield film (12) returns to the second core chip (2) again. At this time, The magnetic flux absorbed by the shield film (12) is reduced, the leakage magnetic flux in the read / write gap g ₂ of the _second core chip (2) is not reduced, and the overwrite characteristic is not deteriorated.

Further, the shield film (12) in the embodiment shown in FIG. 3 has a saw-tooth shape along the medium traveling direction as shown in FIG. 3, and the slider (13) including this shield film (12).
Is manufactured as follows. That is, FIG.
As shown in (d), the surface of the first non-magnetic plate (14) made of ceramic or the like is cut into a sawtooth shape by a dicer (A) or the like, and a metallic magnetic material such as sendust is sputtered or vapor-deposited thereon. Thin film shield film (1
2) is formed, a second non-magnetic material (15) made of glass or the like is glass-molded thereon, and the glass-molded second non-magnetic material (15) is polished to form a thin slider. Get (13).

Further, the shield film (12) in the embodiment shown in FIG. 5 is a corrugated one along the medium traveling direction as shown in FIG. 5, and the slider (13) including this shield film (12) is as follows. It is manufactured as follows. That is, as shown in FIG. 6, the surface of the first non-magnetic plate (14) made of ceramic or the like is cut with a wire saw (B) or the like in a corrugated manner while being shifted by a constant pitch, and a metal magnetic material such as sendust is formed on the surface. A thin film shield film (12) is formed by depositing the body by sputtering or vapor deposition, and a second non-magnetic body (15) made of glass or the like is glass-molded on the shield film (12), and the glass-molded second film is formed. By polishing the non-magnetic material (15), the thin plate slider (13) is obtained.

The shield films (12) in the two embodiments shown in FIGS. 3 and 5 are locally close to the first and second core chips (1) and (2) as shown in FIG. Inflection point (1
6) exists. When recording or reproducing information, for example, the second
At the time of writing information by the core chip (2) of the above, at the inflection point (16) near the second core chip (2), it leaks from the second core chip (2) to the shield film (12) and is absorbed. Since the magnetic flux immediately returns to the second core chip (1), the reduction of the leakage magnetic flux in the read / write gap g ₂ can be further suppressed, and the overwrite characteristic can be improved.

In each of the embodiments described above, the shield film (12)
Since it is a thin film, the distance between the first and second core chips (1) and (2) can be reduced to about 0.05 to 0.25 mm. As a result, when the magnetic head is mounted on the FDD device as shown in FIG. 7, since the distance between the first and second core chips (1) and (2) is small, the area of the medium sliding contact surface (10) can be reduced. It can be made as small as possible, and the contact state between the medium (m) and the gaps g ₁ and g ₂ is stable, and good recording / reproducing characteristics can be obtained.

In the embodiment shown in FIG. 8, a plurality of layers (two layers in the figure) of shield films (12) and (12) are arranged between the first and second core chips (1) and (2). The shield film (12) can be not only linear, but also sawtooth or corrugated. By disposing the plurality of layers of the shield film (12) in this way, the effect of blocking the magnetic flux leaking from the first or second core chips (1) and (2) is further improved. In this embodiment, since the shield film (12) itself is a thin film, the thickness of the slider (13) does not increase even if a plurality of layers of shield film (12) are arranged. The area of (10) does not become large and the contact state with the medium (m) can be maintained in good condition.

Finally, a seal is formed as in the embodiment shown in FIG.
The film (12) is not always the first and second core chips.
(1) It must be the same as the length of (2) along the medium running direction.
Not the length of the first and second core chips (1) (2)
May be below. Thus the length of the shield film (12)
From the second core chip (2) by shortening
The amount of absorption of magnetic flux leakage can be further reduced,
Read / write gap g ₂Further reduce the leakage flux at
It is possible to suppress and improve the overwrite characteristics.
Be done. The shield film (12) is the same as in the previous embodiment.
In addition to the linear shape as shown, it may be serrated or wavy.
Of course.

In each of the above-described embodiments, the writing of information by the read / write gap g ₂ of the second core chip (2) has been described, but the reading of information by the second core chip (2) is explained. The same applies to the writing / reading of information by the read / write gap g ₁ and the erase gap g ₁ ′ of the first core chip (1).

[0029]

According to the present invention, since the thin shield film is arranged between a plurality of core chips, magnetic mutual interference between the core chips can be prevented in advance, and sufficient leakage in the magnetic gap can be prevented. Magnetic flux can be obtained,
Since the contact surface between the medium and the magnetic gap can be made smaller and the contact state between the medium and the magnetic gap is improved, stable recording / reproducing characteristics can be easily realized. Further, since the shield film can be formed into a thin film by a simple means to manufacture a slider, its practical value is great without increasing the cost.

[Brief description of drawings]

FIG. 1 is an enlarged plan view of an essential part showing a first embodiment of the present invention.

2A to 2C are process diagrams showing a procedure for manufacturing a slider including the shield film of FIG.

FIG. 3 is an enlarged plan view of an essential part showing a second embodiment.

4A to 4D are process diagrams showing a procedure for manufacturing a slider including the shield film of FIG.

FIG. 5 is an enlarged plan view of an essential part showing a third embodiment.

6 (a) to 6 (d) are process diagrams showing a procedure for manufacturing a slider including the shield film of FIG.

FIG. 7 is a front view showing a state in which the magnetic head of the present invention is mounted on an FDD device.

FIG. 8 is an enlarged plan view of an essential part showing a fourth embodiment.

FIG. 9 is an enlarged plan view of an essential part showing a fifth embodiment.

FIG. 10 is an overall perspective view showing a conventional example of a magnetic head.

FIG. 11 is an enlarged plan view of an essential part of FIG.

FIG. 12 is an assembly diagram showing a procedure for manufacturing a slider including the shield plate of FIG. 11.

FIG. 13 is a front view showing a state in which a conventional magnetic head is mounted on an FDD device.

[Explanation of symbols]

1, 2 Core chip 10 Medium sliding contact surface 12 Shield film 14 First non-magnetic material plate 15 Second non-magnetic material g ₁ , g ₁ ′, g ₂ Magnetic gap

Claims (5)

[Claims] 1. A magnetic head in which cores made of a ferromagnetic material are joined and integrated, and a plurality of core chips corresponding to different recording densities, each having a magnetic gap formed on a medium sliding contact surface, are arranged parallel to each other at predetermined intervals. 2. A magnetic head, wherein a thin film-shaped shield film made of a metal magnetic material sandwiched by first and second non-magnetic materials is arranged between the core chips. 2. The magnetic head according to claim 1, wherein the shield film has a linear shape, a sawtooth shape, or a wavy shape along the medium traveling direction. 3. A magnetic head in which a plurality of layers of the shield film according to claim 1 are arranged between core chips. 4. A magnetic head, wherein the length of the shield film according to claim 1, 2 or 3 along the medium running direction is equal to or less than the length of the core chip along the medium running direction. 5. A step of manufacturing a plurality of core chips corresponding to different recording densities in which cores made of a ferromagnetic material are joined and integrated, and a magnetic gap is formed in a medium sliding contact surface, and a first non-magnetic material. A step of producing a thin plate-like slider by forming a thin film-like shield film by applying a metal magnetic material to the plate, and forming a thin plate-like slider on the shield film; In parallel with each other, and interposing a slider between them to integrate the core chip and the slider, and a method of manufacturing a magnetic head.