JPH10269533A - Perpendicular magnetic recording composite head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a perpendicular magnetic recording composite head capable of suppressing deviation in recording tracks and reproducing tracks accompanying a skew angle change, improving high track density and reducing a cost with simple constitution. SOLUTION: A reproducing head 17 is arranged in the inside of a recording closed magnetic path 19 so that an upper part shield 3 is parallel to a main magnetic pole 23, and the upper part shield 3 and a lower part shield 1 are set to film thickness of 1-0.8 μm. Since a long distance between the recording head and reproducing head caused by a usual technique arranging the recording head and reproducing head side by side is shortened, even when the skew angle is changed, the matter that the deviation occurs between the tracks of the recording head 18 and reproducing head 17 is suppressed, and recording density in the track width direction and linear direction are improved, and high recording density is obtained. Since the upper part shield 3 and lower part shield 1 are thinned, manufacture is facilitated, and thereby a device is made at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin-film magnetic head for magnetic recording and reproduction, and more particularly to a composite head for perpendicular magnetic recording used for perpendicular recording.

[0002]

2. Description of the Related Art As an example of a conventional magnetic head, there is a thin film head of a longitudinal (in-plane) recording type. In the longitudinal recording type thin film head, a magnetic layer of a magnetic recording medium (hereinafter, referred to as a recording medium) is magnetized in parallel with its surface for recording, and reproduction is performed by using residual magnetization in this surface. However, this thin-film head of the longitudinal recording type has a problem that as the recording density increases, the demagnetizing field in the recording medium increases and the reproduction output decreases. In order to improve this problem, there is a perpendicular recording type thin film head.

In the perpendicular recording type thin film head, information is recorded by magnetizing a recording medium in a direction perpendicular to its surface. In this thin-film head, since the directions of magnetization of the recorded signals do not face each other, the reproduction output does not decrease due to the influence of the demagnetizing field, and the recording density can be increased as compared with the longitudinal recording method. It is known that a combination of a single-pole head for perpendicular recording and a two-layer recording medium exhibits excellent recording resolution (H. Muraoka and Y. Nakamura; IEEE T.
rans. Mag., vo130, p3900, 1994).

In the meantime, both the perpendicular recording type and longitudinal recording type thin film heads have conventionally used a reproducing method based on electromagnetic induction (inductive) for reproducing signals recorded on a recording medium. However, in recent years, with the progress of higher recording density and shorter wavelength of recording / reproducing, the reproducing method by electromagnetic induction,
It has become difficult to deal with high-density recording. For this reason, a magneto-resistance effect type reproducing head (hereinafter, referred to as an MR element) using a magneto-resistance effect element (hereinafter, referred to as an MR element) for reproduction.
(Abbreviated as MR head) has been used.

In the MR head, for example, a reproducing gap is formed at an end (hereinafter referred to as a front end) on the ABS side of a substrate facing a recording medium (hereinafter referred to as ABS) on a substrate serving as a magnetic head slider. It is used by arranging it in the reproduction gap in a longitudinal recording type magnetic head constituted by laminating two thin film magnetic cores (upper shield and lower shield). The MR head is of a type in which MR elements are arranged horizontally (horizontal type M).
R head) and a type in which the MR elements are arranged in an upright state (vertical MR head).

FIGS. 7 and 8 show an example of a longitudinal recording type magnetic head using a horizontal MR head. In FIG.
An upper shield (thin-film magnetic core) 3 is laminated in an insulating layer 2 formed on a lower shield (thin-film magnetic core) 1. In the insulating layer 2 on the upper shield 3, a recording magnetic pole (core) 4 is provided by lamination. Recording magnetic pole 4
Is connected to the upper shield 3 at one end (a side separated from the ABS 5 (hereinafter, appropriately referred to as a rear portion)), and the other end is curved and extends toward the ABS 5. Curved portion 4 of recording magnetic pole 4
A coil 6 is formed in the insulating layer 2 inside the coil a and the insulating layer 2 outside the curved portion 4a so as to wind one end side (connection side with the upper shield 3) of the recording magnetic pole 4.

A reproducing gap 7 is formed between the lower shield 1 and the upper shield 3 in a portion facing the ABS 5 side, and the insulating layer 2 in the reproducing gap 7
A magnetic sensing part 9 having an R element 8 is interposed. Magnetic sensing part 9
Is a SAL film (Soft Adjacent Layer proximity soft magnetic layer, NiFeRh) for applying a magnetic bias in the height direction of the MR element 8 (indicated by the symbol M in FIG. 7), as shown in FIG.
10, an MSL film (current shunt film, Ta) 11, and a thin MR element 8 (NiFe) are laminated.
Above, F which applies a magnetic bias in the lateral direction of the MR element 8
eMn antiferromagnetic film 12 and Ta / W for MR element 8
/ Ta electrodes (leads) 13 are stacked with a gap 14 corresponding to the track width. Note that the magnetic sensing part 9 (MR element 8) has a substantially rectangular shape and extends in the front and back direction on the paper surface of FIG. 7 (horizontal arrangement, constituting a horizontal MR head). In FIG. 8, 14a indicates an optically required track width, and 14b indicates an effective track width that actually functions for reproduction. In FIG. 7, reference numeral 15 denotes a recording medium provided with a magnetic film 16.

In the magnetic head of the longitudinal recording type shown in FIG. 7, a reproducing head 17 is constituted by the lower shield 1, the upper shield 3 and the magnetic sensing part 9. And the reproducing head 1
The recording head 18 is provided so as to line up with the recording head 7 (in FIG. 7, on the upper side of the reproducing head 17). In the recording head 18, a closed magnetic path 19 for recording is formed from the recording magnetic pole 4 having a curved shape, the recording medium 15, and the upper shield 3, and the end of the recording magnetic pole 4 on the ABS 5 side and the upper shield 3.
A recording gap 20 is formed between the recording gap 20 and the end on the ABS 5 side.

At this time, a loop-shaped magnetic path (recording closed magnetic path 19) is formed via a portion of the recording medium 15 corresponding to the recording gap 20, and recording is performed in the surface direction of the recording medium 15 (reference D). ).
This type is called a ring type head. A main magnetic pole and a sub magnetic pole (not shown) are arranged on the ring type head with the recording medium 15 interposed therebetween to form a recording gap (not shown) in a direction perpendicular to the surface of the recording medium 15.
In addition, a type in which information is recorded on the recording medium 15 in a direction perpendicular to the surface without forming a loop-shaped magnetic path, or a loop-shaped magnetic path (a closed magnetic path for recording) is formed.
Type in which a recording gap is formed in a direction perpendicular to the surface of the recording medium 15 and a return magnetic path is formed at a predetermined distance from the recording gap in parallel with the surface of the recording medium 15 (type of FIG. 1 described later). Is called a so-called single pole head, and is distinguished from the ring type head.

In a longitudinal recording type magnetic head using a horizontal type MR head shown in FIG. 7, a recording head 8 is composed of a recording magnetic pole 4, a coil 6, and an upper shield 3, thereby performing recording on a recording medium 15. It is. The upper shield 3 functions as a shield for the MR element 8 and
Plays the role of recording core. For this reason, in order to perform recording efficiently, the thickness of the upper shield 3 is set to a relatively thick 2 μm.
m or more. For this reason, there was a disadvantage that the process cost was high.

The magnetic head shown in FIG.
8 and the reproducing head 17 are arranged side by side, and the recording head 18 and the reproducing head 17 are separated from each other by the thickness of the upper shield 3 (2 μm or more) as shown in FIG. Therefore, when the skew angle (the angle between the tangential direction J of the disk and the center line C of the magnetic head in a swing arm type hard drive) α changes, the track deviation Ls of both the recording head 18 and the reproducing head 17 is changed. There is a problem that occurs.

The vertical type M different from the horizontal type MR head shown in FIG.
FIG. 10 shows an example of a magnetic head using an R head. In FIG. 10, an insulating layer 2 formed on a lower shield 1 is shown.
The upper shield 3 is provided in the inside. A magnetic sensing part 9 is interposed in a portion of the insulating layer 2 between the lower shield 1 and the upper shield 3 on the ABS 5 side. The magneto-sensitive section 9 (MR element 8) has a substantially rectangular shape and extends in the left-right direction on the paper of FIG. 7 (a vertical arrangement, which constitutes a vertical MR head).

The magnetic sensing portion 9 is made of an insulating material made of a non-magnetic material (Al ₂ O ₃ ) between the upper and lower NiFe MR elements 8 (the upper and lower MR elements are shown as 8a and 8b, respectively). Layer 2
A is interposed. ABS5 in insulating layer 2
An electrode 13 (conductive thin film) for the MR element 8 is provided on the side and on the side separated from the ABS 5 (each of the electrodes 13 is hereinafter referred to as a front electrode 13a and a rear electrode 13b). Furthermore, a bias conductor 21 is interposed in the insulating layer 2 between the magnetic sensing part 9 and the upper shield 3 so that the MR element 8 has linear characteristics and good sensitivity.

On the upper shield 3, a recording magnetic pole (not shown) is laminated. The recording magnetic pole and the upper shield 3 are partially connected, and an insulating layer 2 is interposed between the two. The recording magnetic pole and upper shield 3
A coil (not shown) is formed in the insulating layer 2 so as to wind a portion to which is connected.

In the magnetic head using the vertical type MR head shown in FIG. 10, a reproducing head 17 is composed of the upper shield 3, the lower shield 1, the magnetic sensing part 9 and the like. A recording head 18 composed of the recording magnetic pole, the coil and the upper shield 3 is provided alongside the reproducing head 17 (upper side in FIG. 10). The upper shield 3 is composed of the MR element 8
It functions as a shield and also serves as a recording core. For this reason, in order to perform recording efficiently, the thickness of the upper shield 3 is set to a relatively thick film thickness of 2 μm or more. For this reason, there was a disadvantage that the process cost was high.

Also, in the magnetic head of FIG. 10, similarly to the magnetic head of FIG. 7, a recording head 18 and a reproducing head 17 are arranged side by side, and as shown in FIG. 17 are separated by the thickness of the upper shield 3 (2 μm or more). Therefore, similarly to the magnetic head of FIG. 7, when the skew angle α changes, the track of the recording head 18 and the reproducing head 17
There is a problem that the track is shifted.

Another example of a magnetic head having an upper shield 3 and a lower shield 1 is shown in FIG. 11, similarly to the magnetic head of FIG. This magnetic head is of a type having an MR element 8, a so-called composite type (MR / interactive type), and is used for perpendicular recording. Less than,
This type of magnetic head is called a composite head for perpendicular recording. Further, when the head is provided with the upper shield 3 and the lower shield 1 and is distinguished from a yoke system to be described later, this type is referred to as a shield type perpendicular recording composite head.

In FIG. 11, an insulating layer 2 is provided on a substrate 22 serving as a magnetic head slider. Insulating layer 2
On the ABS 5 side, a lower shield 1 and an upper shield 3 constituting a reproducing gap 7 are interposed at a predetermined distance.

Between the lower shield 1 and the upper shield 3, a magneto-sensitive section 9 including a thin-film MR element 8 and a bias conductor 21 is interposed. On the insulating layer 2 on the upper shield 3, a recording main magnetic pole 23 and a thick auxiliary yoke 24 connected to the recording main magnetic pole 23 are arranged.
4, the magnetic resistance of the magnetic circuit is reduced. A return yoke (referred to as a recording return yoke) 25 is connected to the auxiliary yoke 24. The recording return yoke 25 extends to the ABS 5 side. In the insulating layer 2 between the ABS 5 side portion of the recording return yoke 25 and the auxiliary yoke 24, the coil 6 is arranged so as to wind around the connection portion of the recording return yoke 25 with the auxiliary yoke 24. .

This shield type perpendicular recording composite type head has a thick upper shield 3 as shown in FIG.
As with the longitudinal recording magnetic head, the process cost is high. Also, in the magnetic head of FIG. 11, similarly to the magnetic head of FIG. 7 or FIG. 10, the recording head 18 and the reproducing head 17 are arranged side by side, and as shown in FIG. 17 are separated by the thickness of the shield (upper shield 3). Therefore, as in the case of the magnetic head of FIG. 7 or FIG.
8 and the track of the reproducing head 17 are displaced.

FIG. 1 shows a composite type head for perpendicular recording of a type (yoke type) different from the type (shield type) of FIG.
It is shown in FIG. In FIG. 12, a base layer 26 made of alumina is provided on a substrate 22. The insulating layer 2 is provided on the underlayer 26. A main magnetic pole for recording 23 and a thick auxiliary yoke 24 connected to the main magnetic pole for recording 23 are disposed on the insulating layer 2. The provision of the auxiliary yoke 24 reduces the magnetic resistance of the magnetic circuit. I have to. A recording return yoke 25 is connected to the auxiliary yoke 24. The recording return yoke 25 is A
It extends to BS5 side. A of the recording return yoke 25
In the insulating layer 2 between the BS5 side portion and the auxiliary yoke 24, the coil 6 is arranged so as to wind around the connection portion of the recording return yoke 25 with the auxiliary yoke 24.

A reproducing head 17 is disposed in the insulating layer 2 between the recording main magnetic pole 23 and the underlayer 26. The reproducing head 17 has a reproducing main magnetic pole 27 having a substantially U-shaped bent shape.
And a reproducing return yoke 28 connected to the reproducing main magnetic pole 27 and a magneto-sensitive portion 9 including the MR element 8 disposed in the insulating layer 2 in the U-shaped portion 27a of the reproducing main magnetic pole 27. Have been.

In the composite head for perpendicular recording of the yoke type shown in FIG. 12, when the skew angle α is changed, there is no problem that the track of the recording head 18 and the track of the reproducing head 17 are displaced. When the data recorded on the recording medium 15 is reproduced, the reproduction main magnetic pole 27 → the MR element 8 → the return yoke 28 for reproduction → the soft magnetic layer (backing layer) of the recording medium 15 (FIG. 1, backing layer 2)
9) constitutes a closed magnetic circuit for reproduction. For this reason, noise caused by the movement of the magnetic domain of each magnetic material of the reproducing main magnetic pole 27, the reproducing return yoke 28, and the soft magnetic layer (backing layer) of the recording medium 15 appears in the reproduced waveform of the MR element 8. In addition, in the yoke type perpendicular recording composite type head, there is another problem that the magnetic domain structure of the reproducing main magnetic pole 27 must be controlled in order to efficiently reproduce the data.

[0024]

In a magnetic head, it is desired to increase the reproduction sensitivity regardless of perpendicular recording or longitudinal recording. In this case, however, it is necessary to bring the MR element as close as possible to the ABS side, and it is necessary to improve the reproduction resolution. In order to increase the distance, a shield film is required, and the distance between the shields is becoming increasingly smaller.

As shown in FIG. 7, since the magnetic head for longitudinal recording uses the upper shield 3 as a part of the recording head 18, a thick shield film is required, and the process cost is accordingly increased. There are drawbacks.

In the magnetic head shown in FIG. 7, FIG. 10, or FIG. 11, as described above, the recording head 18 and the reproducing head 17 are arranged side by side, and the recording head 18 and the reproducing head 17 are shielded ( When the skew angle α changes, the track of the recording head 18 and the reproducing head 1 are separated by the thickness of the upper shield 3).
The track 7 is shifted. As a countermeasure, there is a method of offsetting the recording head 18 and the reproducing head 17 so that the track deviation between the recording head 18 and the reproducing head 17 is minimized within the range of the skew angle used for the drive, and a method of correcting the recording head 18. For example, the track width may be made larger than the track width of the reproducing head 17. In this case, a wide guard band (a non-recording area between magnetic recording tracks) is required, and the recording track width is set to be larger than necessary than the reproduction track width. It will be.

In the case of the yoke type perpendicular recording composite type head shown in FIG.
Must be minimized to make the MR element 8 as close to the ABS 5 as possible. However, in this case, the MR element 8 is affected by the magnetization of the adjacent bits (bits before and after the bit to be reproduced), and the reproduction resolution is deteriorated (reproduction output at high recording density is reduced, making it unsuitable for high-density recording). ).

The present invention has been made in view of the above circumstances, and it is possible to suppress a shift of a recording track and a reproduction track due to a change in a skew angle, to improve a high track density, and to reduce the cost with a simple configuration. It is an object of the present invention to provide a composite type head for perpendicular magnetic recording capable of performing the following.

[0029]

According to the first aspect of the present invention,
An inductive type comprising a magnetoresistive effect type reproducing head in which an upper shield and a lower shield for a magnetic shield are arranged with a magnetoresistive effect element interposed therebetween, a main magnetic pole of a soft magnetic thin film, and a coil for forming a magnetic path in the main magnetic pole. In the composite type head for perpendicular magnetic recording provided with the recording head described above, the reproducing head is arranged inside the closed magnetic path for recording formed by the recording head so that the upper shield is aligned with the main pole. In addition, the upper shield and the lower shield are set to have a thickness of 0.1 μm to 0.8 μm. According to a second aspect of the present invention, in the configuration of the first aspect, the recording head has an auxiliary magnetic pole connected to the main magnetic pole to prevent magnetic saturation of the main magnetic pole. According to a third aspect of the present invention, in the configuration according to the first or second aspect, the recording head is connected to the main magnetic pole and the leading end side is arranged so as to surround the reproducing head together with the main magnetic pole. It is characterized by having a forming return yoke.

[0030]

FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIG.

In FIG. 1, reference numeral 22 denotes Al ₂ O ₃ —TiC.
And a substrate made of a nonmagnetic material such as Al ₂ O.
_An underlayer 26 made of a nonmagnetic and insulating material such as ₃ is provided. Further, a recording return yoke (return yoke) 25 made of a magnetic material such as NiFe is formed on the substrate 22 having improved planar smoothness by mechanical polishing by plating or the like.
Has been created. The recording return yoke 25 has a substantially L-shape in cross section.
a, a portion orthogonal to and connected to the yoke main body 25a is referred to as a yoke sub-portion 25b. The yoke subportion 25b extends in a direction away from the yoke main body portion 25a, and a main magnetic pole for recording (main magnetic pole) 23 is connected to an end thereof.

The recording main magnetic pole 23 is formed extending from the portion connected to the yoke sub-portion 25b to the ABS 5 side.
The end faces the ABS5. The recording main magnetic pole 23 is formed of a soft magnetic film of NiFe, CoZrNb, FeZrN or the like into a predetermined shape by using ion milling or the like. On the recording main magnetic pole 23, the recording main magnetic pole 2 is placed.
3, a thick film-like auxiliary yoke (auxiliary magnetic pole) 24 is formed. The auxiliary yoke 24 prevents magnetic saturation of the recording main magnetic pole 23. In addition, 2 in FIG.
Is an insulating layer formed using a nonmagnetic insulating material such as Al ₂ O ₃ .

The yoke sub-portion 25b is wound (inserted into the insulating layer 2 in a region surrounded by the recording return yoke 25 and the recording main magnetic pole 23 and the insulating layer 2 outside the region) to form a coil. 6 are provided. The coil 6
It is produced by Cu plating or the like. Between the coil 6 and the recording main magnetic pole 23, the upper shield 3 and the lower shield 1 constituting the reproducing head 17 together with the magneto-sensitive portion 9 are arranged in the insulating layer 2 at a predetermined distance. As shown in FIG. 2, the width H of the upper shield 3 and the width H of the lower shield 1 are set to about 100 μm. Also, upper shield 3
And the thickness of the lower shield 1 are from 0.1 μm to 0.8 μm.
The size is set to μm. In the insulating layer 2 between the upper shield 3 and the lower shield 1, M
A magnetic sensing unit 9 including an R element 8 is provided.

The magnetic sensing part 9 is similar to that shown in FIG.
A non-magnetic material (Al ₂ O) is provided between the upper and lower MR elements 8a and 8b.
₃ ) and a structure in which an insulating layer 2A is interposed. A bias conductor 21 is interposed in the insulating layer 2 between the magnetic sensing part 9 and the upper shield 3, and by giving magnetization in a predetermined direction to the magnetic sensing part 9, the MR element 8 has a linear characteristic and excellent characteristics. I am trying to have sensitivity. The recording main magnetic pole 2
The distance between 3 and the lower shield 1 is the gap length that determines the resolution.

The recording medium 15 includes a backing layer 29 made of a soft magnetic material such as NiFe (permalloy).
It has a two-layered shape formed of a magnetic layer 16 made of a CoCr-based magnetic material and formed on the backing layer 29, and is suitable for perpendicular recording. Note that M
The R element 8 may be of a structure arranged horizontally instead of the type arranged vertically (see FIG. 7).

In the first embodiment, the recording main magnetic pole 23, the auxiliary yoke 24, and the recording return yoke 25
And the coil 6 constitute a recording head 18. The recording head 18 includes an auxiliary yoke 24,
A recording closed magnetic path 19 is formed from the recording main magnetic pole 23 to the recording return yoke 25 via the recording medium 15. The reproducing head 17 is arranged inside the closed magnetic path for recording 19. Also, the recording medium 1
5, a recording gap 20 (between the main recording magnetic pole 23 and the backing layer 29) is formed in a direction orthogonal to the plane of FIG. 5, and information is recorded as shown by an arrow E in FIG. Is a single pole head type.

In this embodiment, since information is recorded in the recording gap 20 between the recording main magnetic pole 23 and the backing layer 29, the upper shield 3 does not function for recording, and the above-described FIG. This is different from the magnetic head shown in FIG. Since the upper shield 3 does not function for recording, the film thickness can be made smaller than that of the prior art.

In this embodiment, the reproducing head 17 is arranged so as to be inside the closed magnetic path for recording 19, and the film thickness of the upper shield 3 and the lower shield 1
Is set to a size of 0.1 μm to 0.8 μm, which is thinner than the conventional technology (for example, the thickness of the shield is 2 μm or more in the magnetic head of FIG. 10). I have to. For this reason, even when the skew angle α changes, it is possible to suppress the occurrence of deviation in the tracks of both the recording head 18 and the reproducing head 17. further,
As described above, the thickness of the upper shield 3 and the lower shield 1
By setting the film thickness to be thinner than that of the prior art, it becomes possible to manufacture the device more easily and the process cost and the cost of the device can be reduced accordingly.

Further, in the above embodiment, since the recording return yoke 25 is arranged so as to cover the upper shield 3 and the lower shield 1, the recording return yoke 25 is provided with the magnetic sensing part 9 (MR). The magnetic shielding function for the element 8) is exhibited, and the shielding property is further improved.

The thickness of the upper shield 3 and the thickness of the lower shield 1 are set to be less than 0.1 μm, and the magnetic sensing part 9 (MR element 8) of the upper shield 3 and the lower shield 1 is set.
As a result of examining the magnetic shielding property of the magnetic recording medium, it was found that the magnetic shielding function deteriorated and the reproduction resolution deteriorated. The reason for setting the thickness of the upper shield 3 and the thickness of the lower shield 1 to 0.1 μm or more as described above is based on this verification result.

As described above, the film thickness of the upper shield 3 and the film thickness of the lower shield 1 are set to 0.8 μm or less.
This is based on the following comparison results. The comparison result will be described below.

For the MR head of the type having a thick shield and the magnetic head of FIG. 1, the state of the track shift Ls that occurs when the skew angle α changes is illustrated.
9 and 3 respectively. Here, assuming that the distance between the recording head 18 and the reproducing head 17 is Lh, Ls = Lh × tanα (1).

Here, for example, in the case of a longitudinal recording MR head, if the length Gr of the reproducing gap 7, the film thickness Ts of the upper shield 3, and the recording gap length Gw, the recording head 18 is used.
Lh = Gr / 2 + Gw + Ts (2) In the MR head actually used, the distance Lh is about 3 μm. At this time, assuming that the skew angle α is 20 °, Ls in Expression (2) is about 1 μm,
A large track deviation Ls will occur.

When the film thickness of the upper shield 3, the lower shield 1, and the recording main magnetic pole 23 was 0.4 μm, it was verified by a separate test that a sufficient shielding effect was obtained. In the case of the present embodiment (FIG. 1), recording is performed at the trailing edge (outflow end; TE portion in FIG. 3) of the recording main magnetic pole 23, so that the film thickness of the recording main magnetic pole 23 is Tm, and the recording is performed. Assuming that the distance between the main magnetic pole 23 and the upper shield 3 is Lm,
The distance Lh between the recording head 18 and the reproducing head 17 is Lh = Gr / 2 + Tm + Lm + Ts (3) where the thickness Ts of the upper shield 3 is 0.4 μm, the thickness of the lower shield 1 is 0.4 μm, and The thickness Tm of the main magnetic pole 23 is 0.4 μm, and the length Gr of the reproducing gap 7 is 0.3.
μm, distance L between the main recording pole 23 and the upper shield 3
If m is 0.2 μm, Lh = 1.15 μm. At this time, assuming that the skew angle α is 20 °, Ls in the equation (2)
Is 0.38 μm, and the track deviation Ls has a small value.

On the other hand, in the structure shown in FIG.
When the thickness of the recording main magnetic pole 23 is set to 1 μm, the recording main magnetic pole 2
Although the recording characteristics of No. 3 were good, the result was that the track shift Ls at this time was 0.6 μm or more, that is, a large track shift occurred. Based on this result, the thickness of the upper shield 3 and the thickness of the lower shield 1 were set to 0.8 μm or less, which is a value less than 1 μm.

Next, the second embodiment of the present invention will be described with reference to FIGS.
An embodiment will be described.

The second embodiment differs from the first embodiment (FIGS. 1 and 2) in that a return yoke 25 for recording is used.
Omitted is different. In the second embodiment, the recording head 18 is composed of the recording main magnetic pole 23, the auxiliary yoke 24, and the coil 6. In this case, when the coil 6 generates a magnetic field, a closed magnetic path 19 for recording is formed, which corresponds to the center of the coil 6 and has the portion where the yoke sub-portion 25b of FIG. Is done. In this case as well, the reproducing head 17 is arranged so as to be inside the closed magnetic path 19 for recording, and the upper shield 3 and the lower shield 1 have a thickness of 0.1 μm to 0.8 μm. Coupled with the fact that the skew angle α is changed in comparison with the prior art, it is possible to suppress the occurrence of deviations in the tracks of both the recording head 18 and the reproducing head 17 even when the skew angle α changes.

Further, the magnetic head of the second embodiment comprises a recording main magnetic pole 23, an auxiliary yoke 24 and a coil 6
And has a relatively flat and simple structure. Therefore, the number of manufacturing steps can be reduced, the manufacturing cost can be reduced, and the yield can be improved since the thick films are stacked and the number of connection portions is small. Further, by setting the film thickness of the upper shield 3 and the film thickness of the lower shield 1 to be smaller than those of the conventional technology, it becomes possible to easily manufacture the same as in the first embodiment,
Accordingly, the process cost and the cost of the apparatus can be reduced.

The current saturation characteristics of the magnetic heads of the first and second embodiments (the horizontal axis represents the product of the recording current and the number of turns of the coil 6;
That is, when the magnetomotive force is obtained), the result shown in FIG. 6 was obtained. In the case of the second embodiment (the magnetic head of FIG. 4), the reproduction output and the O / W value (the erasure rate of the remaining portion of the previous signal when another recording is performed on the signal after recording). In both cases, the magnetomotive force leading to saturation is 1.5 times that of the first embodiment (the magnetic head of FIG. 1), and the O / W value is the same as that of the first embodiment (the magnetic head of FIG. 1). In that case-
40 dB, and in the case of the second embodiment (the magnetic head of FIG. 4), it is -36 dB, and the recording performance is slightly inferior. Judging from the fact that the second embodiment is almost equivalent to the first embodiment, the recording ability of the second embodiment does not pose any problem in practical use.

In each of the above embodiments, the case where the auxiliary yoke 24 is provided has been described as an example. However, if the magnetic saturation of the main magnetic pole does not interfere with recording, the auxiliary yoke 24 may be omitted. With such a configuration, the configuration of the recording head and, consequently, the entire apparatus can be simplified, so that the number of manufacturing steps can be reduced, the manufacturing cost can be reduced, and the yield can be improved.

[0051]

According to the first aspect of the present invention, the thickness of the upper shield and the thickness of the lower shield are set to 0.1 μm to 0.1 μm.
A reproducing head is arranged so as to have a size of 8 μm, which is thinner than the prior art, and is arranged inside the closed magnetic path for recording, and a prior art in which a recording head and a reproducing head are arranged side by side. Since the long distance generated between the recording head and the reproducing head caused by the above becomes short, even when the skew angle changes, it is possible to suppress the occurrence of the deviation of the tracks of both the recording head and the reproducing head, and Along with the improvement of the recording density in the width direction and the improvement of the recording density in the linear direction, it is possible to increase the recording density of magnetic recording. Further, since the recording head is composed of the main magnetic pole and the coil and is composed of a limited number of members, a simple configuration is realized, so that the number of manufacturing steps can be reduced, the manufacturing cost can be reduced, and the yield can be improved.

According to the second aspect of the present invention, the recording head is composed of the main magnetic pole, the coil, and the auxiliary magnetic pole, and is composed of a relatively limited number of members, so that a simple configuration is realized and the number of manufacturing steps is reduced. The production cost can be reduced and the yield can be improved. In addition, the provision of the auxiliary magnetic pole can prevent the magnetic saturation of the main magnetic pole and improve the recording efficiency.

According to the third aspect of the present invention, since the return yoke is arranged so as to surround the magnetoresistive read head, the return yoke surrounds the magnetoresistive element provided in the magnetoresistive read head. Since the magnetoresistive effect element is magnetically shielded, the shielding performance can be improved accordingly.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a composite head for perpendicular recording according to a first embodiment of the present invention.

FIG. 2 is a diagram of the composite head of FIG. 1 as viewed from a surface facing a recording medium.

FIG. 3 is a diagram showing that track deviation is reduced in the composite type head of FIG. 1;

FIG. 4 is a sectional view showing a composite head for perpendicular recording according to a second embodiment of the present invention.

FIG. 5 is a view of the composite head of FIG. 2 as viewed from a recording medium facing surface.

FIG. 6 is a diagram showing magnetomotive force-reproduction output and O / W value characteristics of the first and second composite heads.

FIG. 7 is a sectional view showing a longitudinal recording type magnetic head using a conventional horizontal MR head.

8 is a cross-sectional view showing the magnetic sensing unit in FIG. 7 (a view as seen from the direction of arrow A in FIG. 7).

FIG. 9 is a diagram for illustrating a state of occurrence of track deviation of a magnetic head.

FIG. 10 is a sectional view showing a magnetic head using a horizontal MR head.

FIG. 11 is a sectional view showing an example of a shield type magnetic head.

FIG. 12 is a cross-sectional view illustrating an example of a yoke type perpendicular recording composite head.

[Explanation of symbols]

 Reference Signs List 1 lower shield 3 upper shield 17 reproducing head 18 recording head 23 main pole for recording 24 auxiliary yoke 25 return yoke for recording

Claims (3)

[Claims] 1. A magnetoresistive read head in which an upper shield and a lower shield for a magnetic shield are disposed with a magnetoresistive effect element interposed therebetween, a main pole of a soft magnetic thin film, and a magnetic path formed in the main pole. A composite head for perpendicular magnetic recording comprising an inductive recording head comprising a coil,
The reproducing head is arranged inside the closed magnetic path for recording formed by the recording head so that the upper shield is aligned with the main pole, and the upper shield and the lower shield are set to 0.1 μm to 0.1 μm. A composite head for perpendicular magnetic recording, wherein the thickness is set to 8 μm. 2. The composite type head for perpendicular magnetic recording according to claim 1, wherein the recording head has an auxiliary magnetic pole connected to the main magnetic pole to prevent magnetic saturation of the main magnetic pole. 3. The recording head has a return yoke for forming the closed magnetic path for recording, which is connected to the main magnetic pole and has a distal end arranged so as to surround the reproducing head together with the main magnetic pole. Item 3. The composite head for perpendicular magnetic recording according to item 1 or 2.