JPH11306515A - Magneto-resistive magnetic head and magnetic recording and reproducing device, and manufacturing method of magnet-resistive magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a magnetic head more than a case where a magnetic head is individually formed by arranging plural magnetic head parts of magneto- resistance effect type at predetermined intervals in the direction of the film thickness of the magneto-resistive element so that a magnetic gap formed between a pair of soft magnetic materials becomes approximately parallel to each other. SOLUTION: A magnetic shield 12 forms a magnetic shield shared with a 1st MR head part 10 and a 2nd MR head part 11. The 1st MR head part 10 and the 2nd MR head part 11 are arranged at predetermined intervals in the thickness direction of the MR element part, and the 1st MR head part 10 and the 2nd MR head part 11 are set to form a predetermined azimuth angle to the sliding direction of MR head 6 with a magnetic tape. Moreover, the front and rear end sides in the sliding direction of the MR head 6 are guarded by a pair of guard members 22a, 22b. And, conductor parts 17a, 17b connected with permanent magnets 16a, 16b respectively form their end parts on a side of a magnetic shield 13, which are used as external terminals 23a, 23b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-resistance effect type magnetic head for reproducing information signals from a magnetic tape, a magnetic recording / reproducing apparatus, and a method of manufacturing a magneto-resistance effect type magnetic head.

[0002]

2. Description of the Related Art In a magnetic recording / reproducing apparatus such as a video tape recorder, an audio tape recorder, and a data storage system for a computer using a magnetic tape as a recording medium, in order to increase the recording density and increase the capacity,
Helical scan method is adopted.

In a magnetic tape used in the helical scan system, a recording track on which an information signal is recorded is formed so as to have a predetermined angle (azimuth angle) with respect to the longitudinal direction of the tape.

[0004] The magnetic head reproduces information signals from the magnetic tape by tracing the recording tracks. At this time, in order for the magnetic head to accurately reproduce the information signal from the magnetic tape, it is necessary to perform tracking control so that the magnetic head accurately traces the recording track.

[0005]

In order to accurately perform tracking, the running system of the magnetic tape, the rotation phase of the rotating drum, and the like must be precisely controlled, and the configuration of the apparatus has been complicated. Also, in the case of a magnetic tape, it is necessary to increase the recording track width to some extent in order for the magnetic head to accurately trace the recording track, which hinders an increase in recording density.

On the other hand, there has been proposed a so-called non-tracking type magnetic recording / reproducing apparatus capable of reproducing an information signal from a magnetic tape without performing tracking control.

In a non-tracking type magnetic recording / reproducing apparatus, a plurality of, for example, 2
Using one reproducing magnetic head, the information signal on the recording track is detected by tracing the recording track at double density, and the obtained signal is synthesized to reproduce the information signal from the magnetic tape.

In such a non-tracking type magnetic recording / reproducing apparatus, since a plurality of magnetic heads are mounted on different head bases and mounted on a rotating drum, it is necessary to mount a plurality of magnetic heads on the rotating drum. There was a problem that it was difficult. In addition, when mounting a plurality of magnetic heads on a rotating drum, there has been a problem that positional adjustment between the magnetic heads becomes complicated.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned conventional circumstances, and saves space for a magnetic head mounted on a rotating drum and facilitates mutual position determination of a plurality of magnetic heads. It is an object of the present invention to provide a magnetoresistive magnetic head, a magnetic recording / reproducing device, and a method of manufacturing a magnetoresistive magnetic head.

[0010]

According to the present invention, there is provided a magneto-resistance effect type magnetic head comprising a plurality of magneto-resistance effect type magnetic elements each having a thin film-shaped magneto-resistance effect element sandwiched between a pair of soft magnetic materials via an insulating layer. The head part is arranged and formed integrally,
The plurality of magnetoresistive heads are arranged at predetermined intervals in the thickness direction of the magnetoresistive element such that magnetic gaps formed between the pair of soft magnetic bodies are substantially parallel. It is characterized by having.

In the above-described magneto-resistance effect type magnetic head according to the present invention, since a plurality of magneto-resistance effect type magnetic head portions are integrally formed, a plurality of magnetic heads are formed separately. The magnetic head is downsized.

A magnetic recording / reproducing apparatus according to the present invention is a helical scan type magnetic recording / reproducing apparatus, wherein a substantially cylindrical rotating drum and a thin film-shaped magnetoresistive element mounted on the rotating drum have an insulating layer. A plurality of magneto-resistive magnetic heads sandwiched between a pair of soft magnetic materials are arranged side by side in the film thickness direction of the magneto-resistive element so as to have substantially the same azimuth angle, and are integrally formed. And a plurality of magnetoresistive heads mounted on the rotating drum and having a thin-film magnetoresistive element sandwiched between a pair of soft magnetic bodies via an insulating layer. And a second magneto-resistance effect type magnetic head which is arranged integrally in the film thickness direction of the magneto-resistance effect element so as to have substantially the same azimuth angle.

In the magnetic recording / reproducing apparatus according to the present invention as described above, a plurality of magneto-resistive magnetic heads are arranged integrally at predetermined intervals so as to have substantially the same azimuth angle. Since the apparatus includes the first magneto-resistance effect type magnetic head and the second magneto-resistance effect type magnetic head, information signals can be reproduced from the magnetic tape without performing tracking control. In this magnetic recording / reproducing apparatus, the first and second magnetoresistive heads are
Since a plurality of magnetoresistive heads are integrally formed, the size of the magnetic head can be reduced, and the mutual position of the magnetic head can be easily determined.

The method of manufacturing a magnetoresistive head according to the present invention is directed to a first magnetoresistive effect in which a magnetoresistive element is sandwiched between a pair of soft magnetic materials on one surface of a substrate via an insulating layer. Forming a second type magnetic head portion having a magnetoresistive element sandwiched between a pair of soft magnetic materials via an insulating layer on the other surface of the substrate. The first and second magnetoresistive magnetic heads are integrally formed by forming the first and second magnetoresistive magnetic heads by a thin film process.

In the above-described method of manufacturing a magnetoresistive head according to the present invention, since the magnetoresistive heads are formed on both sides of the substrate, two magnetoresistive heads are provided. The parts can be easily formed integrally.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

A magnetic recording / reproducing apparatus according to the present invention is a magnetic recording / reproducing apparatus using a magnetic tape as a recording medium,
For example, it is used as a video tape recorder, an audio tape recorder or a data storage system for a computer. The magnetic recording / reproducing apparatus according to the present invention is a helical scan type magnetic recording / reproducing apparatus for performing recording / reproducing using a rotating drum, and a magnetoresistive magnetic head as a reproducing magnetic head mounted on the rotating drum. (Hereinafter, referred to as an MR head).

FIG. 1 shows a configuration example of a rotary drum device mounted on a magnetic recording / reproducing apparatus to which the present invention is applied. In addition,
FIG. 1 is a perspective view schematically showing the rotary drum device 1. As shown in FIG. 1, the rotary drum device 1 includes a cylindrical fixed drum 2, a cylindrical rotary drum 3, a motor 4 for driving the rotary drum 3 to rotate, and a pair of inductive units mounted on the rotary drum 3. The magnetic heads 5a and 5b include a pair of MR heads 6a and 6b mounted on the rotary drum 3.

Here, a so-called upper drum type rotary drum device 1 in which a rotary drum 3 is disposed on a fixed drum 2 will be described as an example. However, the present invention relates to a helical scan type magnetic recording / reproducing device. The type of the rotary drum device 1 is not particularly limited. For example, a so-called middle drum type rotary drum device 1 in which a rotary drum 3 is sandwiched between a pair of fixed drums 2 may be used.

In the rotary drum device 1, the fixed drum 2 is a drum that is held without rotating. A lead guide portion 8 is formed on a side surface of the fixed drum 2 along a running direction of the magnetic tape 7. As will be described later, the magnetic tape 7 runs along the read guide portion 8 during recording and reproduction. The rotating drum 3 is arranged so that the center axis of the fixed drum 2 coincides with that of the fixed drum 2.

The rotary drum 3 is a drum that is driven to rotate at a predetermined rotation speed by the motor 4 during recording and reproduction on the magnetic tape 7. The rotating drum 3 is formed in a cylindrical shape having substantially the same diameter as the fixed drum 2.
And the central axes are aligned. A pair of inductive magnetic heads 5a, 5b and a pair of MRs are provided on the side of the rotary drum 3 facing the fixed drum 2.
Heads 6a and 6b are mounted.

Inductive magnetic heads 5a, 5b
Is a recording magnetic head in which a pair of magnetic cores are joined via a magnetic gap and a coil is wound around the magnetic core, and is used when recording data on the magnetic tape 7. The inductive magnetic heads 5 a and 5 b are mounted on the rotating drum 3 such that their magnetic gaps protrude from the outer periphery of the rotating drum 3. The inductive magnetic heads 5a and 5b are set so that the azimuth angles are opposite to each other so that guard bandless recording is performed on the magnetic tape 7 with a predetermined azimuth angle.

These inductive magnetic heads 5
A known recording magnetic head employed in a conventional helical scan type magnetic recording / reproducing apparatus can be used for a and 5b. Specifically, the magnetic core is composed of a soft magnetic material such as ferrite and a metal magnetic film formed on the soft magnetic material, and a pair of magnetic cores is formed by a metal magnetic film sandwiching a magnetic gap. A so-called MIG (Metal In Gap) type magnetic head which is joined so as to be opposed is particularly suitable.

The MR heads 6a and 6b are magnetic heads for detecting an information signal from the magnetic tape 7 by utilizing a magnetoresistance effect, and are reproducing magnetic heads. Generally, MR heads are more suitable for high-density recording because they have higher sensitivity and higher reproduction output than inductive magnetic heads that perform recording and reproduction using electromagnetic induction. Therefore, higher density recording can be achieved by using the MR heads 6a and 6b as the reproducing magnetic head.

Incidentally, these MR heads 6a and 6b
As in the inductive magnetic heads 5a and 5b, the azimuth angles are set to be opposite to each other so that a magnetic signal recorded guardlessly with a predetermined azimuth angle with respect to the magnetic tape 7 can be detected.

The MR heads 6a, 6b
Has an angle of 18 with respect to the center of the rotating drum 3.
0 °, and the MR element is mounted on the rotating drum 3 such that the MR element portion protrudes from the outer periphery of the rotating drum 3.

Hereinafter, the MR heads 6a and 6b will be described. The MR head 6a and the MR head 6b have substantially the same configuration. Therefore, in the following description, these MR heads 6a and 6b are collectively referred to as the MR head 6.

As shown in FIGS. 2 and 3, the MR head 6 has a first MR head section 10 and a second MR head section 11 arranged side by side and formed integrally. FIG. 2 is a perspective view showing an example of the configuration of the MR head 6, and FIG. 3 is an enlarged view of the first and second MR head sections 10, 11 and the vicinity thereof.

The first MR head section 10 has a thin-film MR element section 15 sandwiched between a pair of magnetic shields 12 and 13 made of a soft magnetic material and a pair of magnetic shields 12 and 13 via an insulating film 14. And permanent magnet films 16a and 16b disposed on both sides of the MR element portion 15, and conductor portions 17 connected to the permanent magnet films 16a and 16b, respectively.
a, 17b.

The second MR head unit 11 includes a pair of magnetic shields 12 and 18 made of a soft magnetic material, an MR element unit 20 sandwiched between the pair of magnetic shields 12 and 18 via an insulating film 19, Permanent magnet films 21 a and 21 b disposed on both sides of the element portion 20;
a, 21b, respectively, and a conductor portion (not shown) connected to each of them.

In the MR head 6, the magnetic shield 12 is a magnetic shield shared by the first MR head unit 10 and the second MR head unit 11. Also,
In this MR head 6, the first MR head section 10 and the second
The MR head 11 is arranged at a predetermined interval k in the thickness direction of the MR element. Further, the first MR head unit 10 and the second MR head unit 11 correspond to FIGS.
As shown in the figure, a predetermined azimuth angle θ is set with respect to the sliding direction of the MR head 6 with respect to the magnetic tape 7 indicated by the arrow D. The front end side in the sliding direction and the rear end side in the sliding direction of the MR head 6 are defined as a pair of guard members 22a, 22a.
guarded by b. These guard materials 22
For a and 22b, a non-magnetic material having excellent wear resistance is used.

In the first MR head section 10, the MR element section 15 includes an MR element having a magnetoresistance effect and an SAL.
(Soft Adjacent Layer) film and an insulator film disposed between the MR element and the SAL film. The MR element is made of a soft magnetic material, such as Ni-Fe, whose resistance changes according to the magnitude of an external magnetic field due to the anisotropic magnetoresistance effect (AMR). In addition, the SAL film is a so-called SA
This is for applying a vertical bias magnetic field to the MR element by the L bias method, and is made of a magnetic material having a low coercive force and a high magnetic permeability such as permalloy. The insulator film is to insulate between the MR element and the SAL film and to prevent electrical shunt loss, and is made of an insulating material such as Ta.

The permanent magnet films 16a and 16b disposed on both sides of the MR element section 15 are for applying a horizontal bias magnetic field to the MR element, and are disposed so as to be in contact with both sides of the MR element. , A so-called abut structure. These permanent magnet films 16a and 16b are made of Co-N
It is made of a magnetic material having a large coercive force and conductivity, such as i-Pt or Co-Cr-Pt.

The conductors 17a and 17b connected to the permanent magnet films 16a and 16b are formed on the side surface of one magnetic shield 13 so that their ends are exposed to the outside. The ends of the conductors 17a and 17b are external terminals 23a and 23b for supplying a sense current from the outside to the MR element. That is, the MR elements formed in the MR element section 15 are connected to the conductor sections 17a, 17b from these external terminals 23a, 23b.
In addition, a sense current is supplied via the permanent magnet films 16a and 16b.

In the first MR head section 10, M
As shown in FIG. 4, the R element portion 15 is formed so that the planar shape is substantially rectangular, the short axis direction is substantially perpendicular to the sliding surface 24, and one side surface is A pair of magnetic shields 12 and 13 are exposed so as to be exposed on the sliding surface 24.
Is sandwiched via an insulator 14. And
In this MR head 6, the MR element section 15 is a magnetic sensing section for detecting a magnetic field from the magnetic tape 7, and the length t of the magnetic sensing section is larger than the track pitch Tp of the recording track, and is smaller than the track pitch Tp. It is made smaller than twice.

In the above description, the first MR head 10
Has been described, but the second MR head section 11 has the same configuration as the first MR head section 10, so that
The description of the second MR head unit 11 is omitted.

The MR head 6 is shown in FIGS.
As shown in (1), the first MR head unit 10 and the second MR head unit 11 are arranged in the film thickness direction of the MR element, so that the first MR head unit 10 and the second MR head unit Electrical connection between the external terminals 11 and the external electrodes can be easily performed.

The MR head 6 is mounted on the rotary drum 3 so that at least a part thereof protrudes from the outer peripheral portion of the rotary drum 3. Further, the MR head 6
The sliding surface 24 is cylindrically ground along the sliding direction of the MR head 6 with respect to the magnetic tape 7 as shown by an arrow D in FIGS. 2 and 3, and is orthogonal to the sliding direction. Cylindrical grinding along the direction you want.

As shown in FIG. 5, the magnetic recording / reproducing apparatus slides the magnetic tape 7 on such a rotary drum device 1 to record data on the magnetic tape 7 or to read data from the magnetic tape 7. Play data. Here, FIG. 5 is a plan view schematically showing the magnetic tape feed mechanism 30 including the rotary drum device 1. Specifically, at the time of recording / reproduction, the magnetic tape 7 is sent from a supply reel 31 through guide rollers 32 and 33 so as to be wound around the rotary drum device 1 as shown in FIG. Recording and reproduction are performed.

When recording data on the magnetic tape 7, a pair of inductive magnetic heads 5a, 5b and the magnetic tape 7 are slid, and guard bandless recording is performed by these inductive magnetic heads 5a, 5b. I do.

When reproducing data from the magnetic tape 7, the pair of MR heads 6a, 6b and the magnetic tape 7 are slid, and the pair of inductive magnetic heads 5a, 5b are moved.
b, the data recorded by these MR heads 6
Reproduce by a and 6b.

In the rotary drum device 1, the MR head 6
a and 6b are provided with a plurality of MR heads and a pair of MR heads 6a and 6b having different azimuth angles are mounted. It is possible to reproduce an information signal from the tape 7.

For example, as shown in FIG.
At the recording tracks TA1, TB1,
TA2, TB2,... Are formed. Here, tracks TA1, TA2, TA3,...
Azimuth angle that can be played back on the track TB
1, TB2 and TB3 are azimuth angles that can be reproduced by the MR head 6b.

Here, the track TA2 having a recording azimuth angle that can be reproduced by the MR head 6a will be described as an example. M
The R head 6a has two MR heads, and one of the MR heads first scans the magnetic tape 7 with a locus, and then after one rotation of the rotating drum, the magnetic tape 7
Suppose that the top is scanned with a locus. Hereafter, after one rotation,
One of the MR heads scans the track on the magnetic tape 7. At this time, each trajectory,
For example, it is shifted by one track pitch Tp.

By performing such a scan, one of the MR heads 6a is scanned by each of the trajectories.
7 (a), (b), (c), (d)
The reproduction output shown in FIG. Here, FIG.
Is a reproduction output in scanning the trajectory. FIG. 7 (b)
Is a reproduction output in scanning the trajectory. FIG. 7 (c)
Is a reproduction output in scanning the trajectory. FIG.
(D) is a reproduction output in scanning the trajectory.

That is, in the scanning of the trajectory, FIG.
As shown in the figure, first, the signal of the track TA2 is reproduced a little, and the signal of the track TA1 is reproduced in the remaining portion. In the scanning of the trajectory, as shown in FIG. 7B, the signal of the track TA2 is reproduced first, and the signal of the track TA1 is reproduced slightly in the latter half. In the scanning of the trajectory, as shown in FIG. 7 (c), the signal of the track TA3 is first reproduced a little, and the signal of the track TA2 is reproduced in the remaining portion. In scanning the trajectory, as shown in FIG. 7D, the signal of the track TA3 is reproduced first, and the signal of the track TA2 is reproduced only slightly in the latter half.

The signal recorded on the track TA2 is
As described above, it is divided into several parts and reproduced. Then, by performing predetermined signal processing on the divided and reproduced signal, the signal recorded on the track TA2 can be reproduced.

The other MR head of the MR head 6a also scans the magnetic tape 7 in the same manner. At this time, MR
In the head 6a, when the interval between the two MR heads is k, and the azimuth angle of the MR head 6a is θ,
(K × sin θ) is an integral multiple of the track pitch Tp n ×
The distance k between the two MR heads is set to be equal to Tp.
Is preferably determined. For example, (k × sin
When θ) = Tp, one MR head portion and the other MR head portion of the MR head 6a scan at locations separated by about one track pitch. In other words, when one MR head scans along the trajectory, the other MR head moves about the same trajectory II as the trajectory.
Scan with. When one of the MR heads scans along the locus, the other MR head scans along the locus III substantially the same as the locus.

Therefore, for example, even if a signal is missed when one of the MR heads scans along the trajectory, the trajectory of the other MR head is substantially the same as the trajectory after one rotation of the rotating drum. To scan with III, one M
Signals not detected by the R head can be detected by the other MR head.

As described above, the two MRs of the MR head 6a are
By determining the distance k between the heads as described above, the MR
When a signal is reproduced from the magnetic tape 7 without tracking using the head 6a, the signal from the magnetic tape 7 can be reproduced without leakage. Specifically, for example, Tp
Is 5 μm and θ is 20 °, k is 14.
It is determined to be 6 μm.

As for the MR head 6b, the MR head 6
The signal from the magnetic tape 7 can be reproduced in the same manner as in a. Therefore, in the rotating drum device 1, the information signal can be reproduced from the magnetic tape 7 as described above without performing the tracking control.

Recording and reproduction by the rotary drum device 1 will be described with reference to FIG. 8, which shows a schematic circuit configuration of the rotary drum device 1 and its peripheral circuits.

When data is recorded on the magnetic tape 7 using the rotary drum device 1, first, a current is supplied to the drive coil of the motor 4, whereby the rotary drum 3 is driven to rotate. Then, while the rotary drum 3 is rotating, a recording signal from the external circuit 40 is supplied to the encoder 41 as shown in FIG.

The encoder 41 supplied with the recording signal from the external circuit 40 encodes the recording signal and adds a predetermined error correction code. That is, the encoder 41 functions as an error correction code adding unit that encodes a recording signal from the external circuit 40 and adds an error correction code to data recorded on the magnetic tape 7. The data to which the error correction code has been added by the encoder 41 is supplied to the modulation circuit 42.

The modulation circuit 42 modulates the data sent from the encoder 41 into data comprising, for example, a DC-free code sequence.

The DC output from the modulation circuit 42
Data consisting of a free code string is stored in a recording amplifier 43a.
Alternatively, it is supplied to the recording amplifier 43b. Here, the modulation circuit 42 supplies data to the recording amplifier 43a or the recording amplifier 43b in synchronization with the rotation of the rotating drum 3. That is, the modulation circuit 42 supplies the data to the recording amplifier 43a corresponding to the inductive magnetic head 5a at the time of recording the data by the one inductive magnetic head 5a, and the other inductive magnetic head 5a. At the time of recording data at 5b, the data is supplied to the recording amplifier 43b corresponding to the inductive magnetic head 5b.

The recording amplifier 43a to which data comprising a DC-free code string is supplied from the modulation circuit 42.
Amplifies the recording signal corresponding to the data to a predetermined level and supplies the signal to the signal transmission ring 44a. Similarly,
The recording amplifier 43b to which the data composed of the DC-free code string is supplied from the modulation circuit 42 amplifies the recording signal corresponding to the data to a predetermined level and supplies the signal to the signal transmission ring 44b.

The recording signal supplied to the signal transmission ring 44a corresponding to the one inductive magnetic head 5a is transmitted to the signal transmission ring 43a in a non-contact manner. Then, the recording signal transmitted to the signal transmission ring 45a is supplied to the inductive magnetic head 5a, and data is recorded on the magnetic tape 7 by the inductive magnetic head 5a.

Similarly, the recording signal supplied to the signal transmission ring 44b corresponding to the other inductive magnetic head 5b is transmitted to the signal transmission ring 45b in a non-contact manner. Then, the recording signal transmitted to the signal transmission ring 45b is supplied to the inductive magnetic head 5b, and data is recorded on the magnetic tape 7 by the inductive magnetic head 5b.

On the other hand, when data is reproduced from the magnetic tape 7 by using the rotary drum device 1, first, a current is supplied to the driving coil of the motor 4 in the same manner as when recording data. The drum 3 is driven to rotate. Then, while the rotary drum 3 is rotating, a high-frequency current is supplied from the oscillator 46 to the power drive 47 as shown in FIG. The high-frequency current from the oscillator 46 is converted into a predetermined alternating current by a power drive 47 and then supplied to a power transmission ring 48.

The alternating current supplied to the power transmission ring 48 is transmitted to the power transmission ring 49 in a non-contact manner. The AC current transmitted to the power transmission ring 49 is rectified by the rectifier 50 to be converted into a DC current and supplied to the regulator 51, and the DC current is set to a predetermined voltage by the regulator 51.

The current set to a predetermined voltage by the regulator 51 is applied to the pair of MR heads 6a and 6b.
Is supplied as a sense current.

A reproduction amplifier 52a for detecting a signal from the MR head 6a is connected to the MR head 6a, and a current from the regulator 51 is also supplied to the reproduction amplifier 52a. The MR head 6b has M
Reproduction amplifier 52b for detecting a signal from R head 6b
Is connected, and the current from the regulator 51 is also supplied to the reproducing amplifier 52b.

Here, the MR head 6a has two MR heads 10a and 11a.
Reference numerals 0a and 11a each include an MR element whose resistance value changes according to the magnitude of an external magnetic field. Then, the MR head unit 1
0a and 11a are M due to the signal magnetic field from the magnetic tape 7.
The resistance value of the R element changes, so that a voltage change appears in the sense current. Then, the reproduction amplifier 52a detects this voltage change and outputs a signal corresponding to the voltage change as a reproduction signal.

The reproduction signal from the reproduction amplifier 52a is supplied to a signal transmission ring 53a, and the reproduction signal is transmitted to the signal transmission ring 54a in a non-contact manner.

The reproduction signal transmitted to the signal transmission ring 54a is supplied to the reproduction amplifier 55a, amplified by the reproduction amplifier 55a, and then supplied to the detection circuit 56a. Then, the detection circuit 56a detects data composed of a code string from the reproduction signal supplied from the reproduction amplifier 55a. Here, the data recorded on the magnetic tape 7 is data converted into a DC-free code string. Therefore, the data detected by the detection circuit 56a is data composed of a DC-free code string.

Then, the data detected by the detection circuit is supplied to the signal processing circuit 57 as reproduced data A, where the data is subjected to processing such as error correction processing.

The same applies to the MR head 6b.
It has two MR heads 10b and 11b,
Each of the R head units 10b and 11b includes an MR element whose resistance value changes according to the magnitude of an external magnetic field. And M
The R head portions 10b and 11b are configured so that a voltage change appears in the sense current due to a change in the resistance value of the MR element due to a signal magnetic field from the magnetic tape 7. Then, the reproduction amplifier 52b detects this voltage change and outputs a signal corresponding to the voltage change as a reproduction signal.

The reproduction signal from the reproduction amplifier 52b is supplied to the signal transmission ring 53b, and the reproduction signal is transmitted to the signal transmission ring 54b in a non-contact manner.

The reproduction signal transmitted to the signal transmission ring 54b is supplied to the reproduction amplifier 55b, amplified by the reproduction amplifier 55b, and then supplied to the detection circuit 56b. Then, the detection circuit 56b detects data composed of a code string from the reproduction signal supplied from the reproduction amplifier 55b.

The data detected by the detection circuit 56b is supplied as reproduction data B to the signal processing circuit 57, and is subjected to processing such as error correction processing together with the reproduction data A.

By performing the error correction processing in this manner, even if a reproduced signal is lost, the original data can be reproduced if there is not too much loss in the reproduced signal.

When the circuit configuration is as shown in FIG. 8, a pair of inductive magnetic heads 5a, 5b,
The pair of MR heads 6a and 6b, the rectifier 50, the regulator 51, and the reproducing amplifiers 52a and 52b are mounted on the rotating drum 3 and rotate together with the rotating drum 3. On the other hand, the encoder 41, the modulation circuit 42, the recording amplifiers 43a and 43
b, the oscillator 46, the power drive 47, the reproducing amplifiers 55a and 55b, the detection circuits 46a and 56b, and the signal processing circuit 57 are arranged on a fixed portion of the rotary drum device 1 or separately from the rotary drum device 1. The configured external circuit.

The magnetic tape 7 recorded and reproduced by the rotary drum device 1 is fed to a take-up roll 38 via guide rollers 34 and 35, a capstan 36, and a guide roller 37, as shown in FIG. Can be That is, the magnetic tape 7 is fed at a predetermined tension and speed by the capstan 36 driven to rotate by the capstan motor 39, and the inductive magnetic heads 5a and 5b mounted on the rotary drum 3 driven to rotate and the MR tape Head 6
After contacting with a and 6b at a predetermined contact pressure and sliding, the roll is wound on a winding roll.

As described above, in the rotary drum device 1,
A capstan 38 driven to rotate by a capstan motor 39 functions as contact pressure control means for controlling the contact pressure between the inductive magnetic heads 5a and 5b and the MR heads 6a and 6b and the magnetic tape 7. .

When the magnetic tape 7 is fed in this manner, the rotating drum 3 moves as shown by an arrow A in FIG.
The motor 4 is driven to rotate. On the other hand, the magnetic tape 7
Is sent along the lead guide portion 8 of the fixed drum 2 so as to slide obliquely with respect to the fixed drum 2 and the rotating drum 3. That is, the magnetic tape 7 is fed along the tape guide direction along the lead guide portion 8 so as to slide on the fixed drum 2 and the rotating drum 3 from the tape entrance side as shown by an arrow B in FIG. The tape is sent to the tape exit side as shown by arrow C in FIG.

As described above, the magnetic recording / reproducing apparatus uses the pair of MR heads 6a and 6b in which a plurality of MR heads are integrally formed.
The information signal can be reproduced by the non-tracking method.

Hereinafter, a method for manufacturing such an MR head 6 will be described.

First, a disk-shaped first substrate 12 is prepared. As will be described later, since a large number of MR heads are formed on both surfaces of the first substrate 12, a mirror surface treatment is performed on the surface in order to improve the surface roughness. The first substrate 12 serves as a lower shield of the MR head, and is made of a hard soft magnetic material. Specific examples of the hard soft magnetic material include Ni-Zn polycrystalline ferrite.

Next, as shown in FIGS. 9 and 10, an insulating film 14 serving as a lower gap is formed on the first substrate 12 having a mirror-finished surface by sputtering or the like. As a material of the insulating film 14, for example, Al ₂ O ₃ or the like is preferable in consideration of insulating characteristics, wear resistance, and the like.

Next, as shown in FIG. 11 and FIG. 12, on the first insulating film, a thin film 15a for the MR element section to be the MR element section 15 is formed. As described above, the MR element section 15 includes an MR element for applying a bias magnetic field to the MR element by a so-called SAL bias method, and a soft magnetic film (so-called SAL film) for applying a bias magnetic field to the MR element. Are laminated via an insulating film. As a material of the MR element having a magnetoresistance effect, for example, Ni—F
e and the like. As a material of the soft magnetic film for applying a bias magnetic field to the MR element, for example, NiFeNb
And the like. The bias method of the MR element section 15 and the material of each film constituting the MR element section 15 are not limited to these, and can be arbitrarily changed according to the requirements of the system and the like.

Next, as shown in FIG. 13, FIG. 14, and FIG. 15, permanent magnet films 16a and 16b are formed on both ends of a portion to be the MR element portion 15. This permanent magnet film 16a, 1
6b magnetically stabilizes the MR element. 14 and 15 and FIGS. 16 to 2 described later.
In FIG. 1, a portion corresponding to one MR head unit 10, that is, a portion indicated by a circle A in FIG.

To form the permanent magnet films 16a and 16b, first, a resist is applied on the MR element portion thin film 15a, and the permanent magnet films 1a and 1b are formed by photolithography.
A resist pattern is formed in which the resist is removed only at the portions 6a and 16b. Specifically, a resist pattern having two substantially rectangular openings arranged in the longitudinal direction for one MR head is used. Next, etching is performed using the resist pattern as a mask, and the portion of the thin film 15a for the MR element that is exposed from the mask is removed.

Next, the permanent magnet films 16a and 16b are formed on the entire surface by sputtering or the like while the resist pattern remains. As a material of the permanent magnet films 16a and 16b, for example, Co-Ni-Pt, Co-Cr-
A magnetic material having a large coercive force such as Pt and having conductivity is used. Finally, the resist is removed together with the permanent magnet films 16a and 16b formed on the resist, so that the permanent magnet films 16a and 16b having a predetermined pattern are embedded in the MR element portion thin film 15a.

Next, as shown in FIG. 16 and FIG.
Conductor portions 17a and 17b for supplying a sense current to the R element portion 15 and the MR element portion 15 are formed. Specifically, in order to form the conductor portions 17a and 17b, first, a resist is applied on the MR element portion thin film 15a, and the portion that will eventually become the MR element portion 15 and the conductor portion 17a are formed by photolithography. , 17b and the permanent magnet film 16
A resist pattern is formed in which the resist remains only in the portions where a and 16b are formed. The portions to be the conductor portions 17a and 17b have a substantially rectangular shape, and one end in the longitudinal direction is connected to the permanent magnet films 16a and 16b. Also,
The portion between the permanent magnet film 16a and the permanent magnet film 16b is a portion to be an MR element. Next, etching is performed using the resist pattern as a mask to remove the MR element portion thin film 15a exposed from the mask.

Next, the portions to be the conductor portions 17a and 17b are replaced with conductive films having lower electric resistance. First, a resist is applied, and a resist pattern is formed by photolithography in which the resist is removed from only the portions to be the conductor portions 17a and 17b. Next, etching is performed using this resist pattern as a mask, and the thin film 15a for the MR element portion that is to be the conductor portions 17a and 17b exposed from the mask is removed. After removing the MR element portion thin film 15a at the portions to be the conductor portions 17a and 17b, a conductive film is formed with the resist pattern remaining. Examples of the material of the conductive film include Ti and Cu. Next, by removing the resist together with the conductive film formed on the resist, the conductor portions 17a and 17a are removed.
A state in which a conductive film is formed on the portion b is obtained.

Next, as shown in FIGS. 18 and 19, an insulating film 14 to be an upper gap is formed by sputtering or the like.

Next, as shown in FIGS. 20 and 21, external terminals 23a and 23b for establishing electrical connection with the outside are formed at the ends of the conductors 17a and 17b. Specifically, in order to form the external terminals 23a and 23b, first, a resist is applied, and a resist pattern is formed by photolithography in which the resist is removed only from the portions that become the external terminals 23a and 23b. External terminals 23a, 23
The portion where b is formed is the end of the conductor portions 17a and 17b which is not connected to the permanent magnet films 16a and 16b in the longitudinal direction. Next, using the resist as a mask, the second insulating film 14b exposed from the mask is removed by etching.

Next, a conductive film for external terminals is formed with the resist pattern remaining. In particular,
For example, a conductive film for external terminals is formed by depositing Cu and Au in this order by sputtering or the like. Next, the resist is removed together with the conductive film for external terminals formed on the resist, so that the external terminals 23a and 23b are formed at the ends of the conductors 17a and 17b.

In the above steps, as shown in FIG.
A large number of MR heads 10 are formed on one surface of the substrate 12.

Then, as shown in FIG. 23, the MR head 11 is formed on the other surface of the first substrate 12 in the same manner as when the MR head 10 is formed. In this case, the position of the MR head 10 formed on one surface of the first substrate 12 and the position of the MR head 11 formed on the other surface of the first substrate 12 are the same. In addition, it is necessary to sufficiently perform positioning and the like.

With the above steps, the thin film process for forming the MR head on both surfaces of the first substrate 12 is completed.

Next, the substrate is cut in the horizontal direction for each MR head portion, and a plurality of MR head portions are arranged in a horizontal line on the substrate as shown in FIGS. 24 and 25. Hereinafter, a structure in which a plurality of MR heads are arranged in a row on the substrate in this manner is referred to as an MR head array.

Then, as shown in FIG. 26, a second substrate is cut on one surface of the first substrate 12 cut into the MR head row.
And a third substrate 18 on the other surface of the first substrate 12. A hard soft magnetic material is used for the second substrate 13 and the third substrate 18. Specific examples of the hard soft magnetic material include Ni—Zn polycrystalline ferrite. Here, the second substrate 13 serves as an upper layer shield of the MR head unit 10, and the third substrate 18 serves as an upper layer shield of the MR head unit 11. Second substrate 1
An adhesive such as a resin is used for attaching the third and third substrates 18, for example. At this time, as shown in FIG. 26, the lengths of the second substrate 13 and the third substrate 18 are made shorter than the length of the first substrate 12, so that the external terminals 23a and 23b of the MR head unit 10 are exposed. External terminals 23a, 23
b.

Next, as shown in FIG. 27, in order to divide the MR head array, the MR head array is cut for each MR head. The cutting direction is not perpendicular to the surface on which the MR head is formed as shown in FIG. 27, but is cut at a predetermined angle θ. The cutting angle may be changed according to the system used.

Next, as shown in FIG. 28, a pair of guard members 22a and 22b are attached to the individually cut MR head portions. The guard member 22a is attached to the front end side in the sliding direction of the MR head 6, and the guard member 22b is attached to the rear end side in the sliding direction of the MR head 6. A non-magnetic material having excellent wear resistance is used for the guard members 22a and 22b. Specific examples of the magnetic material having excellent wear resistance include alumina-titanium-carbide.

Finally, the surface to be the sliding surface was subjected to grinding. By making the shape of an arc, the MR head 6 as shown in FIGS. 2 and 3 is completed. At this time, MR
The side surface on the sliding surface side of the element portion is exposed on the sliding surface 24.

[0098]

In the magnetoresistive head according to the present invention, since a plurality of MR heads are integrally formed,
The size of the magnetic head can be reduced.

Further, in the magnetic recording / reproducing apparatus of the present invention, since the MR head in which a plurality of MR heads are integrally formed is mounted, the space of the apparatus can be saved. Further, in this magnetic recording / reproducing apparatus, since a pair of MR heads having different azimuth angles are mounted, information signals can be reproduced from the magnetic tape by non-tracking. Further, in this magnetic recording / reproducing apparatus, since an MR head is used as a reproducing magnetic head, high-density recording can be achieved.

In the method of manufacturing a magnetoresistive head according to the present invention, a plurality of MR heads can be easily formed integrally, and the manufacturing cost can be reduced as compared with the case of manufacturing a plurality of MR heads individually. it can.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a configuration example of a rotary drum device mounted on a magnetic recording / reproducing apparatus to which the present invention is applied.

FIG. 2 is a perspective view showing an example of an MR head mounted on the rotating drum.

FIG. 3 is a plan view of the MR head viewed from a magnetic tape sliding surface side.

FIG. 4 is a diagram schematically showing how data is reproduced from a magnetic tape using an MR head.

FIG. 5 is a plan view schematically showing a configuration example of a magnetic tape feed mechanism including the rotary drum device.

FIG. 6 is a diagram illustrating a scanning locus of an MR head during non-tracking reproduction.

FIG. 7 is a diagram showing a reproduction output during non-tracking reproduction.

FIG. 8 is a diagram schematically illustrating a circuit configuration of the rotary drum device and its peripheral circuits.

FIG. 9 is a diagram for explaining the method for manufacturing the MR head, and is a plan view showing a state where a first insulating film is formed on a first substrate.

FIG. 10 is a sectional view taken along line X ₁ -X ₂ in FIG. 9;

FIG. 11 is a diagram for explaining a method of manufacturing an MR head.
It is a top view showing the state where the thin film for MR elements was formed.

FIG. 12 is a sectional view taken along line X ₃ -X ₄ in FIG. 11;

FIG. 13 is a diagram illustrating a method of manufacturing an MR head.
It is a top view showing the state where a resist pattern was formed on the thin film for MR elements.

FIG. 14 is a diagram illustrating a method for manufacturing an MR head.
It is a top view showing the state where the permanent magnet film was formed.

FIG. 15 is a sectional view taken along line X ₅ -X ₆ in FIG. 14;

FIG. 16 is a diagram illustrating a method of manufacturing the MR head,
It is a top view showing the state where the MR element part and the lead conductor were formed.

FIG. 17 is a sectional view taken along line X ₇ -X ₈ in FIG. 16;

FIG. 18 is a diagram for explaining a method of manufacturing an MR head.
FIG. 3 is a plan view showing a state where an insulating film is formed on an MR head.

19 is a sectional view taken along line X ₉ -X ₁₀ in FIG. 18.

FIG. 20 is a diagram illustrating a method of manufacturing the MR head,
FIG. 3 is a plan view showing a state where external terminals are formed.

[21] In FIG. 20 is a sectional view of X ₁₁ -X ₁₂ line.

FIG. 22 is a diagram illustrating a method of manufacturing an MR head.
FIG. 4 is a plan view showing a state where a number of MR heads are formed on one surface of a first substrate.

FIG. 23 is a diagram illustrating a method of manufacturing the MR head.
FIG. 4 is a plan view showing a state where a number of MR heads are formed on the other surface of the first substrate.

FIG. 24 It is a diagram for explaining a method of manufacturing an MR head,
A state in which the first substrate is cut into an MR head array.
It is a top view showing a state.

FIG. 25 is a sectional view taken along line X ₁₃ -X ₁₄ in FIG. 24;

FIG. 26 It is a diagram for explaining a method of manufacturing an MR head,
A second substrate is cut on the first substrate cut into MR head rows.
FIG. 4 is a perspective view showing a state where a substrate and a third substrate are attached.
You.

FIG. 27 is a diagram illustrating a method of manufacturing an MR head.
FIG. 3 is a plan view showing a cutting direction when an MR head section row is cut for each MR head section.

FIG. 28 It is a diagram for explaining a method of manufacturing an MR head,
Guard material on first substrate cut for each MR head
It is a perspective view which shows the state which stuck.

[Explanation of symbols]

1 rotating drum device, 2 fixed drum, 3 rotating drum, 4 motor, 5a, 5b inductive magnetic head, 6a, 6b MR head, 7 magnetic tape

Claims (6)

[Claims] 1. A plurality of magnetoresistive heads each having a thin-film magnetoresistive element sandwiched between a pair of soft magnetic materials with an insulating layer interposed therebetween. Are arranged at predetermined intervals in the thickness direction of the magnetoresistive element so that the magnetic gap formed between the pair of soft magnetic bodies is substantially parallel. A magnetoresistive magnetic head comprising: 2. The magnetoresistive head according to claim 1, wherein the plurality of magnetoresistive heads are arranged at intervals of an integral multiple of a track pitch. 3. A magnetic recording / reproducing apparatus of a helical scan type, comprising: a substantially cylindrical rotating drum; and a thin film-shaped magnetoresistive element mounted on the rotating drum sandwiched between a pair of soft magnetic materials via an insulating layer. A plurality of magnetoresistive effect type magnetic head sections formed at predetermined intervals in the film thickness direction of the magnetoresistive element so as to have substantially the same azimuth angle. A resistance effect type magnetic head and a plurality of magnetoresistive effect type magnetic head units mounted on the rotating drum and having a thin film-shaped magnetoresistive element sandwiched between a pair of soft magnetic materials via an insulating layer are substantially the same. And a second magneto-resistance effect type magnetic head formed integrally with the magneto-resistance effect element so as to have a certain azimuth angle in the thickness direction of the magneto-resistance effect element. Dress Place. 4. The magnetic recording / reproducing apparatus according to claim 3, wherein said plurality of magnetoresistive heads are arranged at intervals of an integral multiple of a track pitch. 5. A first magnetoresistive head having a magnetoresistive element sandwiched between a pair of soft magnetic materials via an insulating layer on one surface of a substrate by a thin film process, On the other surface of the substrate, a second magnetoresistive head having a magnetoresistive element sandwiched between a pair of soft magnetic materials with an insulating layer interposed therebetween is formed by a thin film process, thereby forming the first magnetoresistive head. A magneto-resistance effect type magnetic head and the second
A method for manufacturing a magneto-resistance effect type magnetic head, wherein the magneto-resistance effect type magnetic head portion is integrally formed. 6. The substrate is made of a soft magnetic material, and is made of a soft magnetic material shared by the first magnetoresistive head and the second magnetoresistive head. 6. The method for manufacturing a magnetoresistive head according to claim 5, wherein: