JPH11195206A - Magnetoresistive thin film magnetic head and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a magnetoresistive combined head capable of performing a high desity and a high frequency recording by using a soft magnetic film having a highly saturated magnetic density on the front part magnetic pole of an upper part and using a soft magnetic film having a high resistivity on the rear part magnetic pole of the upper and a middle part magnetic pole. SOLUTION: Upper part magnetic poles of a thin film combined head are formed by joining the front part magnetic pole of an upper part 22 and the rear part magnetic pole of an upper part 21. At this time, at least the hickness of one side of the poles is gradually reduced in order to reduce leaches of magnetic fluxes of the joining area. Moreover, a soft magnetic plated film which is an Ni-Fe alloy, etc., and whose saturated magnetic flux density Bs is 1.4 to 2.2 T is formed on the front part magnetic pole 22 whose top end part is opposed to a recording gap and the rear part magnetic pole 21 is magnetically connected to the middle part magnetic pole 13 having a high resistivity ρ at its rear part and a soft magnetic sputtered film having the high ρ of not smaller than 80 μΩcm is formed on the pole 21. Thus, the overwriting characteristic of the head by a magnetic saturation is improved by providing the plated film having the high Bs on the front part magnetic pole 22 stipulating a recording with and also the high frequency characteristic of the head is improved by forming the film having the high ρ on the rear part magnetic pole 21.

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 having an MR element utilizing the magnetoresistance effect, and particularly to a thin film magnetic head having a small nonlinear magnetization transition point shift when used for high density high frequency digital recording. Regarding possible magnetic heads.

[0002]

2. Description of the Related Art In recent years, the recording density of a magnetic recording device has been remarkably improved, and in the field of magnetic disk devices for computers, the annual rate is 60%.
%, The recording density is increasing. In order to increase the recording density, in addition to the improvement of the magnetic recording medium, the development of a magnetic head having excellent recording / reproducing characteristics is progressing. 1
1 gigabit per square inch (1 Gb / inch2)
In order to achieve the above-mentioned high recording density, a thin film element (hereinafter referred to as an MR element) utilizing a magnetoresistance effect, which has a much higher reproduction output than the conventional inductive type, has been developed as a reproducing head. Uses a conventional inductive type thin film element utilizing electromagnetic induction.
In reality, the reproducing head and the recording head were formed integrally,
A combined head of inductive recording and MR reproduction is used.

FIG. 7 is a sectional view of a conventional MR compound head currently used. FIG. 8 is a top view of the same, and FIG. 7 shows the vicinity of the air bearing surface in the AA ′ section. FIG. 9 is a front view as viewed from the air bearing surface BB ′ in FIG. The conventional MR composite head of FIG.
0, a lower magnetic pole 111, an insulating layer 112, a middle magnetic pole 1
13 are formed, and a reproducing section 114 composed of an MR element is formed between the lower magnetic pole and the middle magnetic pole. A gap material 115 is formed on the central magnetic pole, and further a coil 116 is formed.
Are formed. Insulating layer 1 to insulate the coil
17, an upper magnetic pole 118 is formed, and a protective layer 119 for protecting them is formed on the uppermost layer.

In the present MR composite head, a recording current is applied to a coil 116 to induce a recording magnetic flux in an upper magnetic pole 118 and a central magnetic pole 113, and a magnetic field leaking from the upper magnetic pole and the central magnetic pole near the recording gap causes the air bearing surface 120 to rotate. The signal magnetization is recorded on a recording medium (not shown in the figure) placed in the vicinity of. At the time of reproduction, the magnetic field generated from the signal magnetization of the recording medium is detected by the MR element 114. In this MR composite head, as shown in FIG.
The width of the upper magnetic pole 118 is smaller than the width of the upper magnetic pole 13, and the width of the upper magnetic pole defines the recording track width Tw.

[0005]

In a magnetic disk drive for a computer, as the linear recording density increases, overwrite (O / W) and nonlinear magnetization transition point shift (Non-magnetic transition) occur.
Linear Transform Shift (hereinafter abbreviated as NLTS) has a problem with insufficient characteristics.
In order to increase the recording density in the future, improvement of O / W and NLTS has been an issue. The NLTS is a phenomenon in which a recorded signal deviates from a position to be originally recorded in recording a digital signal. Also, O /
W is a phenomenon in which, when a long wavelength signal is recorded and then a short wavelength signal is overwritten, the previously recorded long wavelength signal remains without being erased. O / W becomes a problem especially when the recording magnetic field strength and the recording magnetic field gradient are insufficient for a recording medium having a high coercive force. The NLTS is considered to be caused by the fact that the high frequency characteristics of the magnetic pole are insufficient at the time of high frequency and high density recording, and the change of the recording magnetic field is delayed.

Heretofore, as a recording magnetic pole for a thin-film magnetic head, a plating film of an alloy mainly composed of an 83Ni-17Fe (wt%) alloy has been used. Since this material has excellent soft magnetic properties and can be produced by plating, it was suitable as a magnetic pole material for a thin film magnetic head having a narrow track width. However, higher density recording,
As the frequency increases, the following problems arise.

That is, in order to increase the recording density,
It is necessary to increase the coercive force of the recording medium to prevent demagnetization of the recording magnetization due to the demagnetizing field, and reduce the magnetization transition region to increase the output at a high recording density. When the coercive force of the medium is high, a strong recording magnetic field strength for sufficiently recording the signal magnetization is required. However, the above 83Ni-17F
The e (wt%) alloy plating film has a saturation magnetic flux density (hereinafter, referred to as Bs) of about 1 T, and has been used in recent years for a medium having a coercive force of 1.9 × 10E5 A / m (2400 Oe) or more. This causes a problem of magnetic pole saturation and a problem of insufficient recording magnetic field intensity. The lack of recording magnetic field strength
In particular, it appears as deterioration of the O / W characteristic and becomes necessary -30d.
There was a problem that the O / W characteristics below B became -26 dB or more.

On the other hand, the frequency of recording has been increasing at the same time as the recording density has been increased, and a magnetic disk device using a 3.5-inch diameter recording medium has been developed to have a maximum usable frequency exceeding 80 MHz. Is coming. When the operating frequency is increased as described above, the change in magnetic flux of the magnetic pole cannot follow the required change speed of the recording signal, and the change in the recording magnetic field is delayed, thereby deteriorating the NLTS characteristics. Came to occur.

As a means for solving the above problem, it is considered to use a material having high Bs in the recording magnetic pole and high specific resistance (hereinafter referred to as ρ). For example, in the upper magnetic pole, 83N where Bs is about 1T
Bs instead of i-17Fe (wt%) alloy plating film
It is thought that O / W can be improved by using a 45Ni-55Fe (wt%) alloy plating film of about 1.5T. Further, by using a CoTaZr amorphous alloy sputtered film having a high specific resistance for the central magnetic pole instead of the 83Ni-17Fe alloy plated film, high frequency characteristics are improved,
It is considered that the NLTS characteristics can be improved. However, there are the following problems in providing a thin-film magnetic head with improved O / W and NLTS for high frequency and high density recording.

That is, there is a problem that a magnetic material having an extremely high saturation magnetic flux density Bs has a low specific resistance ρ, and a material having a high specific resistance does not have a sufficiently high saturation magnetic flux density. Hereinafter, a state in which Bs is high is abbreviated as high Bs, and a state in which ρ is high is abbreviated as high ρ. In a conventional thin-film magnetic head, the upper magnetic pole basically needs to be formed in a very narrow dimension of about 3 μm or less in order to define the recording track width. A method for accurately forming a magnetic pole having such a shape is as follows. A plating method is suitable. However, a material having a high specific resistance is mainly a material formed by a sputtering method, and there is a problem that there is no magnetic material having a sufficiently high specific resistance, which is conventionally used for a recording magnetic pole and can be formed by a plating method. Was.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to improve the O / W and NLTS of a thin-film magnetic head in order to realize high-density, high-frequency recording. It is.

According to the present invention, a recording gap is provided at an end of a film-shaped middle magnetic pole and an upper magnetic pole magnetically connected at a rear portion, and a coil layer is provided around the rear portion. A magnetic head having an MR element and a lower magnetic pole on the anti-recording gap side, wherein the upper magnetic pole comprises an upper front magnetic pole and an upper rear magnetic pole joined to each other, and the upper front magnetic pole has a recording gap at a front end. And Bs is 1.4 to
A soft magnetic film having a specific resistance of 80 μΩcm or more, wherein the upper rear magnetic pole is magnetically connected to the middle magnetic pole at the rear. This is a magnetoresistive thin-film magnetic head. The larger the value of ρ of the central magnetic pole is, the better, but about 80 to 1500 μΩcm. Also,
Preferably, ρ is in the range of about 80 to 750 μΩcm, and more preferably, ρ is in the range of about 80 to 150 μΩcm. As the material of the central magnetic pole, a Co-based amorphous alloy is preferable, and CoNbZr, CoTaZr, or the like can be selected.

In the MR combined head of the present invention, the upper front magnetic pole can be a plating film and the upper rear magnetic pole can be a sputtered film. Further, it is preferable to use a plating film having Bs of 1.4 T or more in the vicinity of the air bearing surface of the upper magnetic pole that defines the recording track width. On the other hand, it is preferable to use a sputtered film having a high ρ and magnetic permeability for the other portions of the upper magnetic pole and the middle magnetic pole.

In the MR composite head of the present invention, the thickness of at least one of the upper front magnetic pole and the upper rear magnetic pole is gradually reduced in a region where the upper front magnetic pole and the upper rear magnetic pole are joined. It can be a head. By forming the joining region in this way, the magnetic flux leaking from the joining region between the upper front magnetic pole and the upper rear magnetic pole can be reduced.
Examples of this structure include two types of structures. First
Is a structure in which an inclined surface is provided by gradually reducing the thickness of the end of the upper front magnetic pole, and the upper rear magnetic pole is laminated on the inclined surface. The second structure is a structure in which an inclined surface is provided by gradually reducing the thickness of the end of the upper rear magnetic pole, and the upper front magnetic pole is laminated on the inclined surface. In order to improve the adhesion on the inclined surface, the angle of the inclined surface is preferably set to about 15 ° to 45 °. Further, in order to improve the magnetic characteristics, the angle of the inclined surface is set to 2
It is preferable to set the angle to about 0 ° to 30 °.

Further, in the MR composite head of the present invention, the portion of the upper magnetic pole plating film close to the recording gap may be made of a sputtering film having a Bs higher than or equal to the plating film. Further, a soft magnetic film may be disposed between the middle magnetic pole and the recording gap, and the soft magnetic film may be formed of a sputtered film or a plated film having a high Bs.

Further, in the MR composite head of the present invention, the upper front magnetic pole has a base film in contact with the recording gap and a plating film laminated on the base film, and Bs of the base film is the plating film. A thin film magnetic head larger than Bs can be obtained. Further, a thin film magnetic head may be provided in which a middle magnetic pole upper layer film is provided between the middle magnetic pole and the recording gap, and Bs of the middle magnetic pole upper layer film is larger than Bs of the middle magnetic pole.

Further, in the MR composite head of the present invention, an FeC alloy film and a NiFe alloy film are used as a base film of the upper front magnetic pole, a soft magnetic film provided between the middle magnetic pole and the recording gap, or an upper magnetic film of the middle magnetic pole. A thin film magnetic head using a multilayer sputtered film made of Here, as the FeC-based alloy film, a film mainly composed of FeC and the remainder being an additive such as Cr or an FeC film is used. Also, NiF
The e-based alloy film is mainly composed of NiFe and the remainder is Cr.
And the like, or a NiFe film. Further, F is obtained by alternately stacking FeC alloy films and NiFe alloy films.
An e-C / Ni-Fe multilayer sputtered film may be used.

Further, in the MR composite head of the present invention, the upper front magnetic pole has a base film in contact with the recording gap and a plating film laminated on the base film, and Bs of the base film is the plating film. A middle magnetic pole upper layer film is provided between the middle magnetic pole and the recording gap, and the Bs of the middle magnetic pole upper layer film is larger than the Bs of the middle magnetic pole.

Further, in the MR composite head of the present invention, the high Bs plating film used for the upper magnetic pole has Bs of about 1.4.
From T to 1.8T, Ni composition is 40 to 48wt%
Can be used. Alternatively, Co-F with Bs of about 1.4T to about 1.8T
An e-Ni alloy plating film can be used. In addition, when the Ni—Fe-based alloy plating film or the Co—Fe—Ni-based alloy plating film is formed, Bs can be improved from 2.0 T to about 2.2 T by increasing the ratio of Fe. .

In the MR composite head of the present invention, for example, a Co-based amorphous alloy sputtered film can be used as the high ρ sputtered film used for the upper rear magnetic pole or the middle magnetic pole. By selecting the composition of these films,
With 0.8T to 1.5T Bs, 80 to 150μ
It shows a high ρ of Ωcm. In addition, Fe-Hf-N, Fe-
A film made of an Fe-based microcrystalline material such as Ta-C can be used. Furthermore, Fe-Al-O-based, Co-Al
A high ρ sputtered film made of a material in the range of 1000 to 1400 μΩcm, such as an -N type, can be used.

In the MR composite head of the present invention, the high Bs sputtered film used in the vicinity of the recording gap of the upper front magnetic pole or the middle magnetic pole is made of Fe-Hf-N, Fe-Hf-N or Fe-Hf-N.
A film composed of an Fe-based microcrystalline material such as Ta-C;
N-based sputtered films, Fe-C-based sputtered films, and the like are preferable. Further, the high Bs sputtered film includes a main magnetic film such as an Fe—N based sputtered film or an Fe—C based sputtered film,
It can be composed of a multilayer film in which an intermediate film such as i-Fe or Ta is laminated.

Further, in the MR composite head of the present invention, a thin film magnetic head having an upper rear auxiliary magnetic pole having the same composition as the upper front magnetic pole between the upper rear magnetic pole and the middle magnetic pole can be provided. Here, the upper rear auxiliary magnetic pole is a part of the magnetic pole provided at the same time as forming the upper front magnetic pole,
The upper rear magnetic pole and the middle magnetic pole are connected by a magnetic circuit. The upper rear magnetic pole can be flattened by filling the step created by providing the coil with the upper front magnetic pole and the upper rear auxiliary magnetic pole.

When manufacturing the MR composite head of the present invention,
MR on the substrate between the lower magnetic pole and the middle magnetic pole via an insulating layer
A reproducing head having an element is provided, a gap material constituting a recording gap is provided on the middle magnetic pole, a coil wrapped with an insulating material is provided on the gap material, and a slope and a floating surface of the insulating material are provided. An upper front magnetic pole is provided on the gap material near the surface, and an inclined surface is provided by etching an end of the upper front magnetic pole on a side not facing the air bearing surface. In addition, an upper rear magnetic pole is provided, and the inclined surface and the end of the upper rear magnetic pole are joined to each other, and a protective film for protecting these is formed on the uppermost layer to finish the element portion.

In the case of manufacturing the MR composite head of the present invention, an MR element is provided on a substrate between a lower magnetic pole and a middle magnetic pole via an insulating layer, and a gap material for forming a recording gap on the middle magnetic pole is provided. And a coil wrapped with an insulating material is provided on the gap material. Further, an upper rear magnetic pole is formed on the insulating material, and then the end of the upper rear magnetic pole on the air bearing surface side is etched to form a slope. A protective film for providing an upper front magnetic pole on the inclined surface, the insulating material, and the gap material, joining the inclined surface and an end of the upper front magnetic pole, and protecting them on the uppermost layer Can be formed to finish the element portion. The above-described etching may be any of a physical method such as ion milling or a chemical method using an acid solution or the like.

(Function) In the MR composite head of the present invention, as described above, a plating film having a Bs of 1.4 T or more is used in the vicinity of the air bearing surface of the upper front magnetic pole that defines the recording track width. By setting Bs to 1.4 T or more, the problem of magnetic saturation can be solved and O / W characteristics can be greatly improved. Also, by using a plating film for the upper front magnetic pole near the air bearing surface that defines the recording track width, a narrow track width of 3 μm or less can be manufactured with high productivity.

Further, by forming the upper rear magnetic pole and the middle magnetic pole other than the vicinity of the air bearing surface with a sputtered film having a high specific resistance, high frequency characteristics can be improved and NLTS characteristics can be improved. Further, by forming a sputtered film having a higher Bs than the material of the upper front magnetic pole or the middle magnetic pole near the recording gap of the upper front magnetic pole or the middle magnetic pole or both of them, it is possible to reduce the O.S.
/ W can be improved to improve NLTS.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments. FIG. 1 is a sectional view of an MR composite head according to an embodiment of the present invention. In this embodiment, a high ρ is applied to the upper rear magnetic pole 21 and the middle magnetic pole 13 in portions other than the vicinity of the air bearing surface 20.
And a high Bs plating film was used for the upper front magnetic pole 22 near the air bearing surface. Although not shown in FIG. 1, the upper rear magnetic pole 21 extends to the right side of the drawing.
It joins with the middle magnetic pole 13 while bending like the upper front magnetic pole. It is better to join directly between the upper rear magnetic pole 21 and the middle magnetic pole 13 without using the gap material 15.
This is desirable because leakage magnetization can be suppressed. Further, the upper front magnetic pole 22 rides on the upper surface from the inclined surface of the upper rear magnetic pole 21, but the less the degree of the climb, the less the magnetic field leaks from the joint.

FIG. 2 is a sectional view of an MR composite head according to another embodiment of the present invention. In this embodiment, similarly to the embodiment of FIG. 1, a high ρ sputtered film is used for the middle magnetic pole 13 and the upper rear magnetic pole 21 in a portion other than the vicinity of the air bearing surface 20, and the upper front magnetic pole 22 near the air bearing surface is used. A high Bs plating film was used. The upper front magnetic pole 22, which is a plated film, was formed on a base film 23, which was a sputtered film having a larger Bs than the plated film.

FIG. 3 shows an MR according to an embodiment of the present invention.
FIG. 2 shows a cross-sectional view of the composite head. In this embodiment, similarly to FIG. 2, a high ρ sputtered film is used for the middle magnetic pole 13 and the upper rear magnetic pole 21 other than the vicinity of the air bearing surface 20, and the high Bs is applied to the upper front magnetic pole 22 near the air bearing surface. Using a plating film of
Under the plating film that is the upper front magnetic pole 22, a base film 23 that is a sputtered film having a larger Bs than the plating film.
Was formed. Further, on the recording gap side of the middle pole film 13 (on the side of the gap member 15), a middle pole upper layer film 24 having a higher Bs than the middle pole film 13 or a sputtered film was disposed. In the embodiment of FIG. 3, when the base film 23 is not used, or when the Bs of the base film 23 is equal to or less than the Bs of the upper front magnetic pole, the NLTS is almost the same as the embodiment of FIG.
And O / W characteristics are improved. However, it is not improved as much as the embodiment of FIG.

FIG. 4 shows an MR according to an embodiment of the present invention.
FIG. 2 shows a cross-sectional view of the composite head. In this embodiment, the central magnetic pole 1
3, and a high ρ sputtered film was used for the upper rear magnetic pole 21 in a portion other than the vicinity of the air bearing surface 20, and a high Bs plating film was used for the upper front magnetic pole 22 near the air bearing surface. At the end of the upper front magnetic pole 22 not facing the air bearing surface, an inclined surface having a tip angle of about 30 ° was provided to gradually reduce the thickness of the upper front magnetic pole. By directly joining the upper rear magnetic pole 21 on the inclined surface, magnetic field leakage at the joint can be suppressed. In order to most effectively suppress the leakage of the recording magnetic field, it is desirable that the inclined surfaces be joined to each other as shown in FIG.

FIG. 5 shows an MR according to an embodiment of the present invention.
FIG. 2 shows a cross-sectional view of the composite head. In this embodiment, the central magnetic pole 1
3 and a high ρ sputtered film is used for the upper rear magnetic pole 21, and a high Bs is used for the upper front magnetic pole 22 and the upper rear auxiliary magnetic pole 25.
Was used. Further, the undercoat films 23 and 26 having Bs larger than the plating film are formed on the upper front magnetic pole 22 respectively.
And below the upper rear auxiliary magnetic pole 25. Here, the upper rear auxiliary magnetic pole 25 is a portion provided at the same time when the upper front magnetic pole 22 is formed, and connects the upper rear magnetic pole and the middle magnetic pole in a magnetic circuit. The upper rear magnetic pole 21 can be flattened by filling the step created by providing the coil 16 and the insulating material 17 with the upper front magnetic pole 22 and the upper rear auxiliary magnetic pole 25. In FIG. 5, the gap material 15 extends between the upper rear auxiliary magnetic pole 25 and the middle magnetic pole 13. However, the gap material is removed only in this region, and the upper rear auxiliary magnetic pole 25 and the middle magnetic pole 13 are separated. Direct bonding reduces the leakage magnetic field.

FIGS. 1 to 5 described above show the middle magnetic pole 1.
3, the MR element 14 and the lower magnetic pole 11
This is an MR composite head provided with: In these magnetic heads, noise is likely to occur due to the movement of magnetic domains in the magnetic poles unless at least one of the upper front magnetic pole and the upper rear magnetic pole is provided with an inclined surface and joined. Therefore, when an MR element is provided, it is desirable to provide a junction via an inclined surface so that this noise does not propagate from the central magnetic pole to the MR element.

The method for manufacturing the MR composite head of the present invention will be described below. In the embodiment shown in FIG. 1, Al2O3-TiC is used as the substrate 10, and an amorphous alloy sputtered film having a composition of Co83Ta12.2Zr4.8 (at%) to be the lower magnetic pole 11 is formed thereon by a magnetron sputtering apparatus. Formed. The film thickness is 2 μm, and Bs is 0.9
T and ρ were 145 μΩcm. Next, a portion to be left as the lower magnetic pole was protected with a resist, and an unnecessary portion was removed by chemical etching. For the chemical etching, a mixed solution of nitric acid, cobalt sulfate and hydrofluoric acid was used. When the chemical etching is performed, the edge of the soft magnetic film as the lower magnetic pole is etched so as to be inclined with respect to the substrate. The inclination angle between the end face of the soft magnetic film and the substrate was set to about 20 ° to 45 °.

Next, the insulating layer 12 serving as a reproducing gap and the reproducing element 1 comprising the MR element, the electrode, the bias film, etc.
4 was formed. Next, CoTa is formed in the same manner as the lower magnetic pole.
A central magnetic pole 13 made of a Zr amorphous alloy sputtered film was formed. However, the composition of the middle magnetic pole is Co88Ta8Zr4.
(At%), and a film with Bs improved to 1.3T was used. ρ was 120 μΩcm and the thickness was 3 μm. Next, an insulating material 15, a coil 16, and a coil insulating material 17 to be a recording gap were formed. Further, as the upper rear magnetic pole 21, a CoTaZr amorphous alloy sputtered film having the same composition as the middle magnetic pole was formed using a magnetron sputtering apparatus, and the shape of the upper rear magnetic pole was formed by chemical etching in the same manner as described above. The thickness was 3.5 μm. At this time, the air bearing surface side end of the upper rear magnetic pole 21 becomes an inclined surface,
A shape whose thickness was gradually reduced was obtained. This inclined surface was a region where a part of the upper front magnetic pole 22 was laminated.

Next, 45Ni is used as the upper front magnetic pole 22.
A -55Fe (wt%) alloy film was formed by a plating method. The Bs of this film was 1.6 T and the thickness was 3.5 μm. In the plating method, a base film for flowing a plating current is formed in advance by a 45 μm-thick 45Ni-55Fe alloy sputtered film, and a frame-shaped resist is formed thereon so as to surround the periphery of the shape of the upper front magnetic pole. Formed and then plated. As a result, a plating film was formed inside and outside the frame, and an unnecessary underlayer and plating film were removed by ion milling or chemical etching to obtain an upper front magnetic pole having a desired shape. Furthermore, Al
An MR composite head was manufactured by forming a protective material 19 made of 2O3 and processing it into a predetermined shape.

On the other hand, as a manufacturing method in which the order of lamination and the side on which the inclined surface is provided are reversed, a process of forming an upper front magnetic pole, and a method of forming an inclined front end on an end opposite to the air bearing surface. The structure shown in FIG. 4 may be obtained by using a method of manufacturing an MR composite head having a process of providing a surface and a process of joining an upper rear magnetic pole on the inclined surface. That is, a reproducing head having an MR element is provided on a substrate between a lower magnetic pole and a middle magnetic pole with an insulating layer interposed therebetween, and a gap material for forming a recording gap is further provided on the middle magnetic pole. A coil wrapped with an insulating material is provided thereon, and further, an upper front magnetic pole is provided on the slope of the insulating material and on the gap material near the air bearing surface, and the end of the upper front magnetic pole on the side not facing the air bearing surface A manufacturing method in which an inclined surface is provided by etching a portion by ion milling, an upper rear magnetic pole is provided on the inclined surface and the gap material, and the inclined surface and an end of the upper rear magnetic pole are joined.

To form an inclined surface by etching the end of the upper rear magnetic pole or the end of the upper front magnetic pole by ion milling, a method of covering the upper surface with a photoresist mask and side-etching the end is used. Can be used.
At this time, the mask has a two-layer structure consisting of an upper layer and a lower layer,
When the area of the lower layer mask bonded to the upper surface is smaller than the area of the upper layer mask, a smoother inclined surface can be obtained by the ion sneaking effect. The angle of the tip of the inclined surface is in the range of 15 ° to 45 °, but is in the range of 15 ° to 35 ° to maximize the adhesion, and 25 ° to suppress the leakage magnetic field. ~ 28 ° is desirable

FIG. 6, which is another embodiment of the present invention shown in FIG. 2, uses an Fe--C / Ni--Fe multilayer sputtered film as the under film 23 for the upper front magnetic pole.
This film is 90Fe-10C (at%) having a thickness of 45 nm.
The sputtered film 28 is made of 5 nm thick 83Ni-17Fe.
(Wt%) This is a multilayered film with the alloy film 27 interposed therebetween. Although a four-layer film is shown in FIG. 6, when the number of laminations is further increased, the thickness of the entire multilayer film is set to 0.5 μm. This multilayer film has a low ρ, but has a high Bs of 1.9T. Other configurations and manufacturing methods were the same as those of the MR composite head of FIG. The thickness of the plating film of the upper front magnetic pole 22 was 3 μm.

In another embodiment of the present invention shown in FIG. 3, an Fe—C / Ni—Fe multi-layer sputtered film having the same thickness as that described above is formed between the middle magnetic pole and the gap material as the middle magnetic pole upper film 24. Formed at 0.5 μm. CoT, the central magnetic pole
The thickness of the aZr film was 2.5 μm. Other configurations and manufacturing methods were the same as those of the MR composite head of FIG. The results of comparing the recording characteristics of the MR composite head of the present invention produced as described above with those of the conventional MR composite head are described below.

For the measurement of recording characteristics, a 3.5-inch recording medium was used, and the recording characteristics were measured at 5400 rpm. p. m. The measurement was performed on the middle circumference and the outer circumference at the rotation speed of. The recording density at the middle circumference is 175k
FCI, the recording density at the outer periphery is 160 kFCI. The recording medium has a coercive force of 2.0 × 10E5 A / m (2500
Oe), the flying height was about 45 nm. O / W is LF
HF (High Frequency) after recording with LF with respect to the reproduction output when recording with (Low Frequency)
The ratio of the residual power of the LF when it was recorded in the frequency range was measured. NLTS was measured by the fifth harmonic extraction method. The middle LF is 13 MHz, the HF is 65 MHz, the outer LF is 16 MHz, and the HF is 80 MHz.

As a conventional MR composite head for comparison, an MR composite head having a central magnetic pole made of an 83Ni-17Fe (wt%) alloy plated film and an upper magnetic pole made of an 83Ni-17Fe (wt%) alloy plated film, 83Ni
The upper magnetic pole is 4 as a -17Fe (wt%) alloy plating film.
An MR composite head with a 5Ni-55Fe (wt%) alloy plating film, and a 45Ni-55Fe (wt) upper magnetic pole with a central magnetic pole made of a CoTaZr amorphous alloy sputtered film.
%) An MR composite head having an alloy plating film was used. In addition, the recording track width was 2 μm, the recording gap length was 0.3 μm, and the thickness of the lower magnetic pole was 2.5 μm. Table 1 shows the recording characteristics at the middle and outer circumferences when the recording current was 30 mA.

[0042]

[Table 1]

As shown in Table 1, Comparative Example 1 in which the 83Ni-17Fe (wt%) alloy plating film was used for the upper magnetic pole and the middle magnetic pole had a large O / W of -30 dB or more.
The NLTS is also a large value of 30% or more. In Comparative Example 2 using a 45Ni-55Fe (wt%) alloy plating film having high Bs for the upper magnetic pole, the O / W characteristics were improved,
The value was -30 dB or less. However, NLTS is 40
It showed a large value in the% range. Further, in Comparative Example 3 in which a CoTaZr amorphous alloy film having a high
Although both / W and NLTS characteristics were improved, NLTS was still insufficient.

The upper front magnetic pole is made of 45Ni-55Fe (wt
%) In Example 1 using an alloy plating film and a CoTaZr amorphous alloy film for the upper rear magnetic pole, the NLTS was significantly reduced. Further, the underlayer of the upper front magnetic pole is made of Fe-C / Ni-
In Example 2 using the Fe multilayer film and Example 3 using the Fe—C / Ni—Fe multilayer film as the upper layer of the middle magnetic pole,
The O / W and NLTS characteristics were further improved, and an MR composite head suitable for high recording density and high frequency recording was obtained.

In another embodiment having the same composition as in the first embodiment, and having the structure shown in FIG. 4 for the junction between the upper front magnetic pole and the upper rear magnetic pole, the same O / W and NLTS characteristics as in the first embodiment are obtained. Was completed. Further, since the recording magnetic field did not leak from the joint, the magnitude of noise in the reproduction output of the MR element was suppressed as compared with the first embodiment.

In another embodiment in which the same composition as that of the third embodiment is applied to the structure shown in FIG. 5, the NLTS characteristics are different from those of the second embodiment.
And the O / W characteristics were almost the same as in Example 3. This is probably because the recording magnetic field leaked between the upper rear auxiliary magnetic pole and the middle magnetic pole.

[0047]

As described above, the high Bs soft magnetic film is used for the upper front magnetic pole, and the high ρ is used for the upper rear magnetic pole and the middle magnetic pole.
M having excellent O / W and NLTS characteristics under high recording density and high frequency conditions by using a soft magnetic film having
An R composite head was obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of an MR composite head according to the present invention.

FIG. 2 is a cross-sectional view of the MR composite head of the present invention.

FIG. 3 is a cross-sectional view of the MR compound head of the present invention.

FIG. 4 is a cross-sectional view of the MR compound head of the present invention.

FIG. 5 is a cross-sectional view of the MR composite head of the present invention.

FIG. 6 is a cross-sectional view of the MR compound head of the present invention.

FIG. 7 is a sectional view of a conventional MR compound head.

FIG. 8 is a top view of a conventional MR compound head.

FIG. 9 is a front view of a conventional MR compound head.

[Explanation of symbols]

Reference Signs List 10 substrate, 11 lower magnetic pole, 12 insulating layer, 13 middle magnetic pole, 14 reproducing element, 15 gap material, 16 coil, 17 insulating material, 19 protective material, 20 floating surface, 2
1 upper rear magnetic pole, 22 upper front magnetic pole, 23 base film, 24 middle magnetic pole upper layer film, 25 upper rear auxiliary magnetic pole,
26 base film, 2783Ni-17Fe alloy film, 28
90Fe-10C sputtered film.

Claims (11)

[Claims] 1. A recording gap is provided at an end of a film-shaped middle magnetic pole and an upper magnetic pole magnetically connected at a rear portion, and a coil layer is provided around the rear portion. A magnetic head having an MR element and a lower magnetic pole on a gap side, wherein the upper magnetic pole comprises an upper front magnetic pole and an upper rear magnetic pole joined to each other, and the upper front magnetic pole faces a recording gap at a front end. And Bs is set to 1.4 to 2.2T.
Wherein the upper rear magnetic pole is magnetically connected to the middle magnetic pole at the rear, and the upper rear magnetic pole and the middle magnetic pole are soft magnetic films having a specific resistance of 80 μΩcm or more. Magnetoresistive thin film magnetic head. 2. The method according to claim 1, wherein a thickness of at least one of the upper front magnetic pole and the upper rear magnetic pole gradually decreases in a region where the upper front magnetic pole and the upper rear magnetic pole are joined. Magnetoresistive thin film magnetic head. 3. The magnetoresistive thin film magnetic head according to claim 1, wherein the upper front magnetic pole is a plating film, and the upper rear magnetic pole is a sputtered film. 4. The upper front magnetic pole has a base film in contact with a recording gap and a plating film laminated on the base film, wherein Bs of the base film is larger than Bs of the plating film. 4. A magnetoresistive thin film magnetic head according to claim 1, 2 or 3. 5. The magnetoresistive effect according to claim 4, wherein said underlayer is composed of a (Fe—C / Ni—Fe) multilayer sputtered film composed of an FeC-based alloy film and a NiFe-based alloy film. Type thin film magnetic head. 6. A soft magnetic film is provided between the middle magnetic pole and the recording gap, and Bs of the soft magnetic film is larger than Bs of the middle magnetic pole. A thin film magnetic head according to any one of the above. 7. The soft magnetic film is made of an FeC alloy film and NiFe.
7. The magnetoresistive thin-film magnetic head according to claim 6, wherein the magnetoresistive thin-film magnetic head is constituted by a multilayer sputtered film made of a system alloy film. 8. The upper front magnetic pole has a base film in contact with a recording gap and a plating film laminated on the base film, wherein Bs of the base film is larger than Bs of the plating film. 4. The magnetoresistive thin film according to claim 1, wherein a middle magnetic pole upper layer film is provided between the recording gaps, and Bs of the middle magnetic pole upper layer film is larger than Bs of the middle magnetic pole. Magnetic head. 9. An upper rear auxiliary magnetic pole having the same composition as the upper front magnetic pole is provided between the upper rear magnetic pole and the middle magnetic pole. , 7 or 8. 10. A reproducing head provided with an MR element between a lower magnetic pole and a middle magnetic pole via an insulating layer on a substrate, and a gap material forming a recording gap is provided on the middle magnetic pole. A coil wrapped with an insulating material is provided on the gap material, and further, an upper front magnetic pole is provided on the slope of the insulating material and on the gap material near the floating surface, and the upper front portion on a side not facing the floating surface. An inclined surface is provided by etching the end of the magnetic pole, an upper rear magnetic pole is provided on the inclined surface and the insulating material, and the inclined surface and an end of the upper rear magnetic pole are joined. A method for manufacturing a magnetoresistive thin-film magnetic head. 11. An MR element is provided on a substrate between a lower magnetic pole and a middle magnetic pole via an insulating layer, a gap material forming a recording gap is provided on the middle magnetic pole, and an insulating material is formed on the gap material. After providing the coil wrapped in, furthermore, after forming the upper rear magnetic pole on the insulating material, by etching the end of the upper rear magnetic pole on the floating surface side, to provide an inclined surface, the inclined surface and the insulating material A method for manufacturing a magnetoresistive thin-film magnetic head, comprising: providing an upper front magnetic pole on the gap material; and joining the inclined surface and an end of the upper front magnetic pole.