JPH08153312A - Magnetic head and magnetic disk device - Google Patents

Abstract

(57) [Abstract] [Purpose] A magnetoresistive effect reproducing head part having a magnetoresistive effect element and a conductor layer for supplying a sense current to the magnetoresistive effect element, and reading information from a magnetic recording medium. The present invention relates to a composite type magnetic head and a magnetic disk device which have a pair of magnetic poles formed of thin films and are laminated with an induction type recording head section for recording information on a magnetic recording medium. An object of the present invention is to realize a magnetic head and a magnetic disk device which can reduce the curvature of a magnetic pole and the resistance of a conductor layer and can read information accurately and with high sensitivity in a range where the off-track is small. [Structure] As the conductor layer 6, a magnetic head and a magnetic disk device are formed by using a thin portion of a portion 6A near the magnetoresistive effect element portion 2A and a thick portion of another portion 6B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive effect reproducing head having a magnetoresistive effect element and a conductor layer for supplying a sense current to the magnetoresistive effect element and reading information from a magnetic recording medium. And a pair of magnetic poles formed of a thin film, and a composite type magnetic head in which an induction type recording head section for recording information on a magnetic recording medium is laminated, and a magnetoresistive effect type magnetic head. The present invention relates to a magnetic disk device that reads information from a magnetic recording medium by using a reproducing head unit and records information on the magnetic recording medium by using an inductive recording head unit.

In recent years, there has been a demand for a magnetic disk device having a large capacity and a small size, and the areal recording density has been increased.

[0003]

2. Description of the Related Art As a high-density magnetic head, a magnetoresistive head using a magnetoresistive element whose electric resistance changes according to the strength of a magnetic field is known. A magnetoresistive head is generally called an MR head (MR is an abbreviation for magnetoresistive), and an AMR head utilizing an anisotropic magnetoresistive effect (AMR is an abbreviation for anisotropic magnetoresistive).
And a GMR head (GMR head) that utilizes the giant magnetoresistive effect.
Is an abbreviation for giant magnetoresistive).

The AMR head is, for example, NiFeCr.
A soft adjusent layer made of a magnetized magnetic material such as (nickel-iron-chromium);
A non-magnetic intermediate layer such as (tantalum), a magnetoresistive layer (MR layer) such as NiFe (ferrite), and an antiferromagnetic material F
BCS (boundary control stabilizatio) formed of eMn (iron-manganese) and in a substantially magnetized state
n) layer and BC with a distance corresponding to the recording track width
A pair of conductor layers for supplying a sense current provided in parallel on the S layer are laminated in this order to form a magnetoresistive effect element portion, and the BCS layer causes the magnetoresistive layer to be magnetized in the width direction of the recording track. A bias is applied and a soft adjusting layer is applied to the magnetoresistive layer in a direction perpendicular to the magnetic bias of the BCS layer.

On the other hand, the GMR head makes possible a higher density than the AMR head by utilizing the giant magnetoresistive effect. The magnetoresistive effect element part of the GMR head also has a laminated structure in which a plurality of magnetic layers are laminated with a non-magnetic intermediate layer interposed therebetween, and a pair of sense current supply conductors juxtaposed at intervals corresponding to the recording track width. Layers
It is attached to this magnetoresistive effect element part, and both are common in this respect.

FIG. 9 shows a conventional example of a composite type magnetic head, in which a magnetoresistive effect reproducing head section is used for reading information and an inductive recording head section (thin film head) is used for recording information. FIG. 10 is a diagram showing the main part of the thing.
FIG. 3 is a plan view showing a magnetoresistive effect element portion and a conductor layer therein.

In these figures, 10 is a track of a magnetic recording medium, 20 is an inductive recording head section for recording information on the magnetic recording medium, and 30 is a magnetoresistive effect reproducing head section for reading information. Is. Recording head unit 20
Is a lower magnetic pole (upper shield layer) 21 made of NiFe or the like.
The upper magnetic pole 22 made of NiFe or the like and the magnetic poles 21 and 22 which are opposed to the lower magnetic pole 21 at a constant distance from the track are excited, and information is recorded on the recording track 10 of the magnetic recording medium at the recording gap portion. It is composed of a coil 23 and the like for recording A non-magnetic insulating layer 24 made of Al ₂ O ₃ or the like is provided in the space around the coil 23 without any gap.

The reproducing head unit 30 is an AMR head or a GMR.
The magnetoresistive effect element section 30A has a pair of conductor layers 31 for supplying a sense current to the magnetoresistive effect element section 30A with an interval corresponding to the recording track width. It is provided.

The laminated state of the recording head section 20 and the reproducing head section 30 will be described with reference to FIG. FIG. 11 is a cross-sectional view showing the laminated structure near the recording gap when the magnetic head in FIG. 9 is viewed from the magnetic recording medium side. In FIG. 11, reference numeral 25 denotes a ceramic substrate on which a non-magnetic insulating layer 26 made of Al ₂ O ₃ or the like, a lower shield layer 27 made of NiFe or the like, or a non-magnetic layer made of Al ₂ O ₃ or the like. The insulating layer 28 is formed in this order, and the reproducing head unit 3 is formed.
The magnetoresistive effect element portion 30A of 0 has the nonmagnetic insulating layer 2
8 is formed. If the magnetoresistive effect element section 30A of the reproducing head section 30 is composed of an AMR head, for example, a soft adjusting layer, a nonmagnetic intermediate layer such as Ta, a magnetoresistive layer such as NiFe, and a BC such as FeMn.
The S layer is sequentially formed on the nonmagnetic insulating layer 28. The magnetoresistive effect element section 30A is provided on the magnetoresistive effect element section 30A.
In order to supply the sense current to A, a pair of conductor layers 31 having a constant film thickness (conventionally, this film thickness is 1000 to 1200Å) are formed at intervals corresponding to the recording track width.

Further, a nonmagnetic insulating layer 32 is formed on the magnetoresistive effect element section 30A and the conductor layer 31, and the above-mentioned recording head section 20 is formed on this. That is, Ni
A lower magnetic pole (upper shield layer) 21 made of Fe or the like, a coil 23 (not shown in FIG. 11), a nonmagnetic insulating layer 24 made of Al ₂ O ₃ or the like, and an upper magnetic pole 22 made of NiFe or the like are arranged in this order. Has been formed. Finally, the recording head unit 20
A protective layer 33 made of Al ₂ O ₃ or the like is formed outside the upper magnetic pole 22 to cover the surface of the above.

[0011]

However, in the magnetic head having the above structure, as is apparent from FIG. 11, due to the existence of the conductor layers 31 arranged in parallel at intervals, the formation after the conductor layers 31 are formed. The upper layer film to be formed will be formed in a corrugated form. In particular, the lower magnetic pole (upper shield layer) 21 near the conductor layer 31 is greatly curved. When the magnetic poles 21 and 22 are curved, the shape of the recording gap facing the magnetic recording medium is also curved, and the recording shape (magnetic pattern) at the end of the recording gap on the magnetic recording medium is considerably distorted. Therefore, if there is a deviation between the position on the track of the magnetic head at the time of recording information and the position on the track of the magnetic head at the time of reading, the recording information at the end of the recording gap on the magnetic recording medium will be recorded in the reproducing head section. Will also read
The magnetic disk device cannot read information accurately. That is, the conventional magnetic head of this type has a problem that a read error occurs even though the off-track amount is small.

In order to solve this problem, it is conceivable to form the conductor layer 31 thinly.
The resistance of the conductor layer 31 increases and the voltage drop there increases, which makes it difficult to detect the resistance change of the magnetoresistive element portion with high sensitivity. As a result, a new problem arises that the S / N becomes worse. In addition, the heat generated in the conductor layer 31 causes a new problem that noise is generated.

The present invention has been made in view of the above problems, and an object of the present invention is to reduce the curvature of the magnetic pole of the recording head portion, reduce the resistance of the conductor layer, and accurately in the range where the off-track is small. Moreover, it is to realize a magnetic head and a magnetic disk device capable of reading information with high sensitivity.

[0014]

SUMMARY OF THE INVENTION The present invention relates to a magnetic head, which has a magnetoresistive effect element and a conductor layer for supplying a sense current to the magnetoresistive effect element, and which reads information from a magnetic recording medium. An effective playback head section,
A composite type magnetic head having a pair of magnetic poles formed of a thin film, and an induction type recording head portion for recording information on a magnetic recording medium, is laminated, It is characterized in that a portion near the resistance effect element portion is formed thin and other portions are formed thick.

Here, in addition to reducing the thickness of the conductor layer, not only the thickness of the conductor layer but also the portion other than the vicinity of the magnetoresistive effect element portion should be made wider to reduce the curvature of the magnetic pole and reduce the thickness of the conductor layer. It is preferable from the viewpoint of lowering the resistance.

In order to form a thick portion of the conductor layer other than the vicinity of the magnetoresistive effect element portion, it is effective to form the conductor layer into multiple layers. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device, a magnetoresistive effect reproducing head having a magnetoresistive effect element and a conductor layer for supplying a sense current to the magnetoresistive effect element, and an inductive type having a pair of magnetic poles formed of a thin film. A magnetic head of the composite type in which the recording head section of the above is laminated, the information is read from the magnetic recording medium by using the magnetoresistive head, and the magnetic recording medium by using the inductive thin film head. In a magnetic disk device for recording information on a recording medium, the film thickness of the conductor layer is characterized in that a portion near the magnetoresistive effect element portion is formed thin and other portions are formed thick.

Further, the laminated structure of the recording head portion and the reproducing head portion in the magnetic head and the magnetic disk device of the present invention will be described with reference to the drawings. 1 is a principle view of a magnetic head and a magnetic disk device according to the present invention. FIG. 1 is a sectional view showing main parts of a recording head and a reproducing head, and FIG.
It is a -B sectional view.

In FIGS. 1 and 2, reference numeral 1 is an inductive recording head section for recording information on a magnetic recording medium, and 2 is a magnetoresistive reproducing head section for reading information. The recording head unit 1 includes a lower magnetic pole (upper shield layer) 3 made of NiFe or the like, an upper magnetic pole 4 made of NiFe or the like facing the lower magnetic pole 3 at a constant interval, and these magnetic poles 3, 3.
4 is excited to form a coil 5 for recording information on the magnetic recording medium in the recording gap portion.

The reproducing head section 2 is composed of an AMR head, a GMR head or the like, and on the magnetoresistive effect element section 2A, a pair of sense currents is supplied to the magnetoresistive effect element section 2A. The conductor layers 6 are provided at intervals corresponding to the recording track width. Here, the film thickness of the conductor layer 6 is 6A near the magnetoresistive effect element portion 2A.
Is formed thin, and the other portion 6B is formed thick.

[0020]

In the structure shown in FIGS. 1 and 2, the thickness of the conductor layer 6 is
Since the portion 6A near the magnetoresistive effect element portion 2A is thin, the curvature of the lower magnetic pole (upper shield layer) 3 and the like is small. Therefore, the shape of the recording gap facing the magnetic recording medium does not curve so much, and even if the position of the magnetic head on the track during recording of information and the position of the magnetic head on the track during reading slightly deviate,
The magnetic disk drive can read information accurately,
It is possible to avoid a situation where a reading error occurs even if the off-track amount is small.

On the other hand, since the thickness of the conductor layer 6 is thicker in the portion 6B other than the vicinity of the magnetoresistive effect element portion 2A, the resistance of the conductor layer 6 can be reduced as a whole. It becomes possible to detect the resistance change of the magnetoresistive element portion 2A with high sensitivity, and the S / N is improved. or,
It is possible to avoid heat generation in the conductor layer 6, and it is possible to prevent generation of noise due to heat generation.

[0022]

3 is a sectional view showing an embodiment of the present invention relating to a magnetic head, and FIG. 4 is a perspective view showing a magnetoresistive effect element portion and a conductor layer in FIG. In these figures, FIG.
1 and parts corresponding to those in FIG. 12 are denoted by the same reference numerals, and description of overlapping parts will be omitted.

The difference between this embodiment and the structures of FIGS. 11 and 12 is the structure of the conductor layer 31 and the structure associated therewith. That is, in this embodiment, the conductor layer 31 is thinly formed in the portion 31A in the vicinity of the magnetoresistive effect element portion 30A (for example, 1200 Å or less; thinner is better) and thicker in the other portion 31B ( For example, 3000 to 400
0Å or a portion 31 near the magnetoresistive effect element portion 30A
2 to 4 times that of A).

To form a thick portion 31B of the conductor layer 31 other than the vicinity of the magnetoresistive effect element portion 30A, the conductor layer 31
It is effective to form a multi-layer by film formation. In this embodiment, as shown in FIG. 4, the conductor layer 31 formed of two layers is used. First, the first layer 31-1 (for example, a film thickness 1200) is used.
Å or less), and then, only in the 31B portion of the first layer 31-1, the second layer 31-2 (for example, a film thickness of 1800 to 220)
0Å) is laminated.

The information recording / reproducing operation in the above embodiment is as follows.
It is exactly the same as the conventional one. That is, when recording information on the magnetic recording medium, a current is passed through the coil of the recording head unit to generate magnetic flux in the magnetic poles 21 and 22. As a result, a leakage magnetic flux is generated in the recording gap portion of the magnetic poles 21 and 22, and information is recorded on the magnetic recording medium.

On the other hand, the reading of information from the magnetic recording medium is carried out by utilizing the difference in the electric resistance of the magnetoresistive element section 30A when an external magnetic field is applied from the magnetic recording medium and when it is not applied. Specifically, the resistance change in the magnetoresistive element section 30A is detected via the conductor layers 35 and 36, and the magnetic head outputs it as a reproduction signal.

In this embodiment, since the conductor layer 31 is thin in the portion 31A near the magnetoresistive effect element portion 30A, the curvature of the lower magnetic pole (upper shield layer) 21 and the like is small. Therefore, the shape of the recording gap facing the magnetic recording medium does not curve so much, and even if the position of the magnetic head on the track during recording of information and the position of the magnetic head on the track during reading slightly deviate, The magnetic disk device can read information accurately, and can avoid a situation where a reading error occurs even if the off-track amount is small.

Further, since the conductor layer 31 is thick and wide in the portion 31B other than the vicinity of the magnetoresistive effect element portion 30A, the resistance of the conductor layer 31 can be reduced as a whole ( According to the experiments conducted by the inventor of the present application, it is easy to reduce the resistance of about 10Ω conventionally to about 7 to 8Ω), and as a result, it is possible to detect the resistance change of the magnetoresistive element section 30A with high sensitivity. Enabled, S / N
Also improves. Further, heat generation in the conductor layer 31 can be avoided, and generation of noise due to heat generation can be prevented.

In the above embodiment, the conductor layer 31 is formed thick and wide in the portion 31B other than the vicinity of the magnetoresistive effect element portion 30A, but it may be thickened. Further, the connecting position of the conductor layer 31 is not limited to the position shown in FIG. 4 as long as the sense current can flow in a predetermined direction.

A large number of magnetic heads are formed on a ceramic head substrate by using a thin film technique. After that, the head substrate is cut into individual heads and processed into a predetermined shape to obtain the slider with the magnetic head shown in FIG. 5, on the surface of the slider 40 facing the magnetic recording medium, levitation force generating rails 41 and 42 are provided along the direction of the air flow generated by the rotation of the magnetic recording medium. Slopes 41a and 42a are formed on the air inflow side portions of the air bearing surfaces of the rails 41 and 42.
Then, on the rear end surface of the rail 42 of the slider 40,
The magnetic head 45 shown in FIG. 3 is formed.

An embodiment of the present invention relating to a magnetic disk device is constructed using the magnetic head and slider of FIG. Embodiments of the present invention relating to a magnetic disk device will be described below.

FIG. 6 is a plan view of a magnetic disk device using the slider with the magnetic head of FIG. 5 (state where the cover is removed), FIG. 7 is a sectional view taken along line AA in FIG. 6, and FIG. 8 is a suspension in FIG. FIG.

In these figures, reference numeral 50 designates a plurality of magnetic disks (three in this embodiment) as magnetic recording media which are rotationally driven by a spindle motor 52 provided on a base plate 51.

Reference numeral 53 is an actuator rotatably provided on the base plate 51. A plurality of head arms 54 extending in the recording surface direction of the magnetic disk 50 are formed at one rotating end of the actuator 53. A spring arm 55 is attached to the rotating end of the head arm 54, and the slider 40 is attached to the flexure portion of the spring arm 55 so as to be tiltable via an insulating film (not shown). On the other hand, a coil 57 is provided at the other rotating end of the actuator 53.

A magnetic circuit 58 composed of a magnet and a yoke is provided on the base plate 51, and the coil 57 is arranged in the magnetic gap of the magnetic circuit 58. The magnetic circuit 58 and the coil 57 constitute a moving coil type linear motor (VCM: voice coil motor). The upper portion of these base plates 51 is covered with a cover 59.

Next, the operation of the magnetic disk device having the above structure will be described. When the magnetic disk 50 is stopped,
The slider 40 is in contact with the retreat zone of the magnetic disk 50 and is stopped.

Next, when the magnetic disk 50 is rotationally driven at high speed by the spindle motor 52, the airflow generated by the rotation of the magnetic disk 50 causes the slider 40 to fly above the disk surface with a minute interval.
When a current is applied to the coil 57 in this state, a thrust is generated in the coil 57 and the actuator 53 rotates. As a result, the head (slider 40) can be moved onto a desired track of the magnetic disk 50 to read / write data.

In this magnetic disk device, since the conductor layer of the magnetic head has a thin portion in the vicinity of the magnetoresistive effect element portion and a thick portion in the other portion, the magnetic pole of the recording head portion is curved. Information can be read accurately and with high sensitivity in a range where the off-track is small and the resistance of the conductor layer is reduced while the resistance is reduced.

[0039]

As described above, according to the present invention relating to the magnetic head, since the film thickness of the conductor layer is thin in the vicinity of the magnetoresistive effect element portion, the lower magnetic pole (upper shield layer), etc. The curvature of becomes smaller. Therefore, the shape of the recording gap facing the magnetic recording medium does not curve so much. Moreover, since the thickness of the conductor layer is formed thicker except the portion in the vicinity of the magnetoresistive effect element portion, the resistance of the conductor layer is reduced as a whole.

Here, the resistance of the conductor layer can be further reduced not only by reducing the thickness of the conductor layer but also by forming a wide portion in the width other than the vicinity of the magnetoresistive effect element portion.

Further, if the conductor layer is formed into a multi-layered structure, the work of forming the conductor layer thicker than the vicinity of the magnetoresistive effect element portion becomes easy. On the other hand, also in the present invention relating to the magnetic disk device, since the conductor layer of the magnetic head, which is thinly formed in the vicinity of the magnetoresistive effect element portion, is used, the position on the track of the magnetic head during recording of information is Even if the position of the magnetic head on the track at the time of reading is slightly deviated, information can be accurately read, and it is possible to avoid a situation where a reading error occurs even if the off-track amount is small.

Moreover, since the thickness of the conductor layer is thicker in portions other than the vicinity of the magnetoresistive effect element portion, the resistance of the conductor layer can be reduced as a whole, and as a result, the magnetoresistive element portion can be reduced. It becomes possible to detect the resistance change of 1 with high sensitivity, and the S / N is improved. Further, it is possible to avoid heat generation in the conductor layer, and it is possible to prevent generation of noise due to heat generation.

[Brief description of drawings]

FIG. 1 is a principle diagram of a magnetic head and a magnetic disk device of the present invention.

FIG. 2 is a sectional view taken along line BB in FIG.

FIG. 3 is a sectional view showing an embodiment of the present invention.

4 is a perspective view showing a magnetoresistive effect element portion and a conductor layer in FIG.

FIG. 5 is an explanatory diagram of a slider with a magnetic head.

FIG. 6 is a plan view of a magnetic disk device using the slider with the magnetic head shown in FIG.

7 is a cross-sectional view taken along the line AA in FIG.

FIG. 8 is a perspective view of the suspension shown in FIG.

FIG. 9 is a diagram showing a main part of a conventional example relating to a composite type magnetic head.

10 is a plan view showing a magnetoresistive effect element portion and a conductor layer in FIG.

11 is a cross-sectional view showing a laminated structure in the vicinity of the recording gap of the magnetic head shown in FIG.

[Explanation of symbols]

 1, 20: recording head part 2, 30: reproducing head part 2A, 30A: magnetoresistive effect element part 3, 21: lower magnetic pole (upper shield layer) 4, 22: upper magnetic pole 5, 23: coil 6, 31: conductor Layer 10: Track 24: Insulating Layer 25: Head Substrate 27: Lower Shield Layer 40: Slider 45: Magnetic Head 50: Magnetic Disk 51: Base Plate 52: Spindle Motor 53: Actuator 54: Head Arm 55: Spring Arm 57: Coil 58 : Magnetic circuit 59: Cover

Claims (4)

[Claims] 1. A magnetoresistive effect reproducing head portion having a magnetoresistive effect element and a conductor layer for supplying a sense current to the magnetoresistive effect element, for reading information from a magnetic recording medium, and formed of a thin film. A magnetic head of a composite type having a pair of magnetic poles that are formed, and an inductive recording head portion for recording information on a magnetic recording medium, and a magnetoresistive effect element with respect to the film thickness of the conductor layer. A magnetic head characterized in that a portion near the portion is formed thin and other portions are formed thick. 2. A magnetoresistive effect reproducing head portion for reading information from a magnetic recording medium, which has a magnetoresistive effect element and a conductor layer for supplying a sense current to the magnetoresistive effect element, and is formed of a thin film. A magnetic head of a composite type having a pair of magnetic poles that are formed, and an inductive recording head portion for recording information on a magnetic recording medium, and a magnetic resistance in relation to the thickness and width of the conductor layer. A magnetic head characterized in that a portion in the vicinity of the effect element portion is formed thin and the other portion is formed thick and wide. 3. The multilayer structure according to claim 1, wherein the conductive layer is formed into a multi-layered structure to thicken a portion of the conductive layer other than a portion in the vicinity of the magnetoresistive effect element portion. Magnetic head. 4. An inductive recording head having a magnetoresistive effect element and a magnetoresistive effect reproducing head section having a conductor layer for supplying a sense current to the magnetoresistive effect element, and a pair of magnetic poles formed of a thin film. A magnetic head of the composite type in which a magnetic field is read from the magnetic recording medium using the magnetoresistive head, and information to the magnetic recording medium is recorded using the inductive thin film head. The magnetic disk device for performing the recording according to claim 1, wherein, with respect to the film thickness of the conductor layer, a portion in the vicinity of the magnetoresistive effect element portion is formed thin and another portion is formed thick.