JPS5994218A - Recording and reproducing magnetic head - Google Patents

Abstract

PURPOSE:To obtain the titled magnetic head which can perform both recording and reproducing and suited especially to the vertically magnetized recording/ reproducing purpose, by using a magneto-resistance element, a current terminal made of a magnetic matter of high permeability and connected to the end part of said magneto-resistance element and a coil wound by the current terminal in a body. CONSTITUTION:A magneto-resistance element 17 is formed on the surface 16 of a nonmagnetic substrate 15a, and an insulated film 18 is formed on the surface 16 as well as the surface of the element 17. Then a current terminal 19a is connected to an end part 17a. Thus a magnetic head is obtained. An insulated film 20 is formed on the surface of the head, and a current terminal 19b is so formed as it covers the terminal 19a via the film 20. This terminal 19b is connected electrically only to the end part 17b of the element 17. The entire upper part is covered with a nonmagnetic substrate 15b, and furthermore both substrates 15a and 15b are held between protecting members 21a and 21b. A coil 22 is wound around the whole part of both substrates through a gap between members 21a and 21b. The recording and reproducing are performed by supplying a signal current to the coil 22 and flowing a fixed DC current to the terminals 19a and 19b respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a magnetic head for recording and reproducing that can be used for both recording and reproducing, and particularly to a magnetic bed for recording and reproducing that is suitable for perpendicular magnetization recording and reproducing.

[Technical background of the invention and its problems]

In recent years, perpendicular magnetization recording has attracted attention as a recording method that can significantly improve the recording density of magnetic recording. This method magnetizes signals in a direction perpendicular to the surface of the magnetic recording medium, and provides a higher recording density than the general recording method that magnetizes signals in the surface direction.

An outline of this perpendicular magnetization recording method will be explained using figures. FIG. 1 shows a method of perpendicular magnetization recording using a so-called main pole excitation type magnetic head. The main pole excitation type magnetic head (1) has a main pole (1) made of a high magnetic permeability magnetic material.
2), a side member (3), and a coil (4) wound integrally with these metal parts. The main pole (2) is attached to the side member (3) with its tip (5) fully protruding. This magnetic head (1) is
The tip (5) is the magnetic layer (7) of the magnetic recording medium (6).
is placed so as to face the In this state, coil (4)
By passing a signal current through, the side member (3) and the main pole (2) are fully excited, the generated magnetic field is concentrated on the tip (5), and the magnetic layer (7) is magnetized in the perpendicular direction.

By the way, if the magnetic head (1) is used to reproduce the magnetic recording medium (6) recorded with perpendicular magnetization in this manner, the output voltage is so small that reproduction is virtually impossible. . Therefore, for reproduction, a conventional ring-shaped reproduction head must be prepared separately from that for recording. In that case, the recording magnetic head (1)
The magnetic head for reproduction must be separated from the magnetic head in terms of position.

Therefore, in order to record and reproduce the same recording track with both magnetic heads, highly accurate alignment is required. Spatial space is also an issue. Additionally, providing separate magnetic heads for recording and reproduction is time-consuming, especially when using a multi-track head to reproduce a signal from one track and record it on another track. The problem is the misalignment.

Therefore, a single magnetic head for perpendicular magnetization recording and reproduction is required. As such a magnetic head for both recording and reproduction, the one shown in FIG. 2 is known. The recording/reproducing magnetic head (8) in FIG. 2 is a magnetoresistive element (9).
and a main magnetic pole (10), an insulating film (11) interposed between the two, and a coil (12) wound around the main magnetic pole (10).
It is composed of. The magnetoresistive element (9) is formed of, for example, a Ni-Fe alloy thin film, and has the property that its electrical resistance changes depending on the magnetic field. On one side of the magnetoresistive element (9), a main pole (10) made of a high magnetic permeability magnetic film is formed with an insulating film (11), which is a non-conductive thin film of 840 □, sandwiched therebetween. and the main magnetic pole (10)
A coil (12) is wound around. The magnetic head (8) configured in this manner is arranged such that the tip (13) of the layered film faces the magnetic layer (7) of the magnetic recording medium (6).

Perpendicular magnetization recording by this magnetic head (8) is performed by the main magnetic pole (1
This is done by passing a signal current through the coil (12) wound around the coil (12). That is, a signal current is passed through the coil (12) to excite the main magnetic pole (10), and the magnetic J@ (7) is magnetized in the vertical direction by the magnetic field generated from its tip.

On the other hand, signal reproduction is performed as follows. That is, when the magnetic recording medium (6) recorded with perpendicular magnetization is run,
The electrical resistance of the magnetoresistive element (9) changes in response to changes in the magnetic field applied from the magnetic layer (7).

Therefore, as shown in FIG. 3, a constant direct current (I) ffi is applied to the magnetoresistive element (9),
9) is detected as a voltage change (v) across the magnetoresistive element (9) to obtain a reproduced output. Note that this reproduction output is amplified by an amplifier (14) and extracted as a reproduction signal.

Now, this recording/reproducing magnetic head (8) has several problems as follows. First, this magnetic head (8)
This is simply a combination of a main magnetic pole (10), which is essentially for recording only, and a magnetoresistive element (9), which also has a function only for reading, in parallel.

Therefore, the distance between the positions of the recording and reproducing heads is much shorter than if they were provided separately, but recording and reproducing at the same point cannot be achieved, which is the essence of the problem mentioned earlier. This is not a practical solution. Also, related to this, when trying to improve recording efficiency using this magnetic head (8), one method is to move the winding position of the coil (12) as close to the tip (13) as possible. It is possible that it will come back. However, the coil (12) is too close to the tip (13).
When the t-turn is made, not only the main pole (10) but also the magnetoresistive element (9) itself is excited. Main magnetic pole (10)
and the magnetoresistive element (9) are located in parallel with each other with an insulating film (11)' interposed therebetween. Therefore, when recording is performed with the coil (12) wound near the tip (13) of the magnetic head (8), the main magnetic pole (10) and the magnetoresistive element (
9) are respectively opposed to the magnetic recording medium (6), recording is performed at two points. Therefore, the structure adopted by the magnetic head (8) is such that recording efficiency cannot be easily improved. Furthermore, in general, when the tip of a magnetic head has a multilayer structure, a new problem of peeling occurs when it comes into contact with and slides on a magnetic recording medium. Forming a strong multilayer structure to deal with this problem is extremely difficult in terms of manufacturing and difficult to realize. Therefore, the conventional recording/reproducing magnetic head (8) is difficult to put into practical use.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a magnetic head for recording and reproducing that is capable of both recording and reproducing, and is particularly suitable for perpendicular magnetization recording and reproducing.

[Summary of the invention]

The recording/reproducing magnetic head of the present invention is composed of a magnetoresistive element, two current terminals connected to the ends of the magnetoresistive element, and a coil integrally wound with these current terminals. This is a magnetic head whose current terminals are made of a high permeability magnetic material.

The magnetic head of the present invention can perform recording by excitation of the current terminal by passing a signal current through a coil around the current terminal, and by concentrating the generated magnetic field on the magnetoresistive element. Further, by supplying a direct current to the current terminal and using it, it also functions as a reproducing head like a normal magnetoresistive magnetic head.

[Embodiments of the invention]

Hereinafter, one embodiment of the recording/reproducing magnetic head of the present invention will be described in detail with reference to the drawings. First, the structure of the recording/reproducing magnetic head of the present invention will be explained with reference to FIG. 4, together with its manufacturing process.

First, a non-magnetic substrate (15a) made of sapphire, Zn ferrite, etc. is prepared. This non-magnetic substrate (15a
) After mirror polishing the surface (16), a magnetoresistive element (17) is formed on the surface (16). Magnetoresistive element (
17) is a ferromagnetic material having a magnetoresistive effect, for example, an alloy thin film (too much) of NiFe, N1-Co, etc.
It is formed with a thickness of approximately (Figure 1 (a))
Next, an insulating film (18) is formed on the surface (16) of the substrate (15a) and the surface of the magnetoresistive element (17). At this time, the end (17a) of the magnetoresistive element (17), (17
b) is left exposed without being covered with the insulating film (18). The insulating film (18) is a non-conductive thin film such as 5 in 1, and is formed by means such as sputtering. End (17a)
, (17b) may be exposed by once forming an insulating film and then removing that portion, or may be exposed by covering with a mask and performing sputtering.

(FIG. 1(b)) Next, proceed to electrode formation. The end (17a) of the magnetoresistive element (17) is exposed and not covered with the insulating film (18).

Current terminal (t9a) on each of (17b); (19
b) This process is carried out in two stages. First, a first current terminal (19a) is connected to the e-end (17a). The current terminal (19m) is formed by, for example, a Ni re alloy film (thickness of several μm>f: spark, vapor deposition, etc.) (see Fig. 1(C)
)) After forming the first current terminal (19a), 810. An insulating film (20) is formed by using a method such as the insulating film (20), and a second current terminal (19b) is further formed so as to cover the first current terminal (19a) via this insulating film (20). This second current terminal (19b) is electrically connected to a magnetoresistive element (
This means that it is connected only to the end (17b) of 17).

(Fig. 1(d)) By gauging the above process, a non-magnetic substrate (15a) is formed.
On top is a magnetoresistive element (17) and its end (17a).

(17b), respectively connected to current terminals (19a);
(19b) was formed, but after this, the entire upper part thereof was covered with the second non-magnetic substrate (15b), and further the inner substrate (1511), (tsb) t-protection member (
21a) and (21b). protection member (21a),
(21b) has a U-shape and is bonded to the substrates (15a) and (15b), respectively, with the concave portions facing each other. As a result, the substrates (15a), (15b)
A gap is created between the protective member (21a), (21b), and the substrate (15a), (15b) is passed through this gap.
) A carp, A= (22), is wound around the whole.

Therefore, this coil (22) is connected to the substrate (15a),
(15b) to the current terminal (19a), (19b
) 'Fr is wound integrally. lastly,
A recording/reproducing magnetic head (24) is completed by polishing the surface (23) facing the magnetic recording medium into a t-circular shape. (FIG. 5) Now, a recording and reproducing method using the magnetic head for recording and reproducing (24) of the present invention obtained according to the above manufacturing procedure will be explained with reference to FIG. 6, taking perpendicular magnetization recording as an example. FIG. 6 schematically shows the recording/reproducing magnetic head (24). First, record the coil (22
) by passing a signal current through. That is, by passing current through the coil (22) every time, the coil (22)
2) The current terminal (19a) is wound by the current terminal (19a).

(19b) is excited and generates a magnetic field. Current terminal (1
9al, (19b) is connected to the magnetoresistive element (17).

Therefore, the generated magnetic field is focused by this magnetoresistive element (17) K placed opposite the magnetic recording medium (6), and recording is performed by magnetizing the magnetic layer (7) in the perpendicular direction. be.

On the other hand, reproduction is performed as follows. That is, as mentioned earlier, when the recorded magnetic recording medium (6) is run t, the electrical resistance of the magnetoresistive element (17) changes due to the magnetic layer (
7) changes according to changes in the magnetic field.

Therefore, a constant DC current (I) is fully passed through the magnetoresistive element (17) through the current terminals (19a) and (19b), and the change in electrical resistance of the magnetoresistive element (17) is controlled by the magnetoresistive element (17). The reproduction output value is detected as a voltage change (v) across both ends of the signal, and reproduction is thereby performed.

Note that a bias current magnetic field is often required to improve the nonlinearity of the magnetoresistive element (17) with respect to the magnetic field. In this case, the coil (22) also receives direct current during playback.
By passing a current, the required bias current magnetic field can be obtained.

In addition, in Fig. 6, (19c) and (19d) indicate lead wires connected to the current terminals (19a) and (19b), respectively, and the direct current (I) is transmitted through these lead wires (19c) and (19d).
19c).

(19d) k through, current terminal (19a), (19b
).

〔Effect of the invention〕

According to the magnetic head of the present invention having the above configuration, both recording and reproduction can be performed using a single magnetic head.

Furthermore, this recording and reproducing is performed at exactly the same point using a magnetoresistive element (one force).A magnetic head that utilizes the property of a magnetoresistive element, whose resistance changes according to changes in the magnetic field, usually Although it is only used as a head, the present invention has succeeded in overcoming this conventional wisdom.

Since the recording and reproducing magnetic head of the present invention can perform recording and reproducing at the same point, there is no positional deviation between the recording position and the reproducing position. Therefore, especially when the magnetic head of the present invention is used as a multi-trunk head and information reproduced from one track is recorded on another track, no time lag t of information occurs.

Furthermore, since the tip of the magnetic head of the present invention does not have a multilayer structure unlike the conventional magnetic head (8), when used in contact with a magnetic recording medium, there is no problem of peeling of the tip. .

Furthermore, the magnetic head of the present invention has a simple structure and is easy to manufacture.

In addition, in the above embodiment, the current terminal (19b) which is an electrode
covers the current terminal (19a) via an insulating film (20). By adopting such a structure, the current terminal (19al+ (t9b), which is the excited body) is integrated and has sufficient thickness.Thereby, the excitation field focused by the magnetoresistive element (17) The strength of the current terminal (19a) increases, and the recording efficiency improves.Of course, the current terminal (19a).

(19b) is not limited to this, and may be provided in parallel instead of being integrated.

Furthermore, since the magnetic head of the present invention has a thin-film magnetoresistive element that focuses the magnetic field during recording, it is suitable as a magnetic head for perpendicular magnetization recording and reproducing to achieve high-density recording. There is no problem in using it when recording in the plane direction.

[Brief explanation of drawings]

Fig. 1 is a basic configuration diagram of a conventional magnetic head for perpendicular magnetization recording, Fig. 2 is a basic configuration diagram of a conventional magnetic head for perpendicular magnetization recording/reproduction, and Fig. 3 is a reproduction method using a magnetoresistive element. 4 is a perspective view showing the manufacturing process of the magnetic head for recording and reproducing of the present invention, FIG. 5 is a completed diagram of the magnetic head of the present invention, and FIG. 6 is a schematic circuit diagram for explaining the present invention. FIG. 1 is a basic configuration diagram of a magnetic head of the present invention. 17... Magnetoresistive element, 17a,
17b...Track/end. 19a, 19b... Current terminal, 20.
・・・・・・Insulating film. 22...Coyle agent Patent attorney Noriyuki Chika (and 1 other person) No. ! Figure 1 Figure 2 Special opening H59-94218 (5) Figure 4

Claims (2)

[Claims] (1) A first magnetoresistive element made of a ferromagnetic material and a high magnetic permeability magnetic material connected to an end of the magnetoresistive element.
A magnetic head for recording and reproducing is characterized in that it is composed of a second current terminal and a coil that revolves around the current terminal 1. (2) A magnetic head for recording and reproducing according to claim 1, wherein the first current terminal is covered with a second current terminal via an insulating film.