JP2002280217A - Soft magnetic film and thin-film magnetic head using the same, and method for manufacturing soft magnetic film and method for manufacturing thin-film magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soft magnetic film, having a saturated magnetic flux density Bs higher than saturated magnetic flux density Bs of an Ni-Fe alloy and superior corrosion resistance by optimizing a composition ratio of a Co-Fe alloy, a thin-film magnetic head using the soft magnetic film and a method for manufacturing the soft magnetic film, and to provide a method for manufacturing the thin-film magnetic head. SOLUTION: A lower pole layer 19 and/or an upper pole layer 21 are formed of the Co-Fe alloy, containing Fe of 50 to 90 mass%. Thus, the saturated magnetic flux density can be set to 2.0 or higher. A centerline mean roughness Ra of the film surface can be set to 9 nm or smaller. An Fe amount of the Co-Fe alloy is set to 65 to 75 mass%, and thus the saturated magnetic flux density Bs can be set to 2.3 T or higher. Accordingly, recording density can be enhanced, and the thin-film magnetic head having superior corrosion resistance can be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can improve the saturation magnetic flux density Bs of a CoFe alloy used as a core material of a thin-film magnetic head, for example, as compared with the saturation magnetic flux density Bs of a NiFe alloy. The present invention relates to a soft magnetic film, a thin film magnetic head using the soft magnetic film, a method for manufacturing the soft magnetic film, and a method for manufacturing the thin film magnetic head.

[0002]

2. Description of the Related Art For example, a magnetic material having a high saturation magnetic flux density Bs is used for a core layer of a thin-film magnetic head, especially in connection with a higher recording density in the future, and a magnetic flux is concentrated near a gap of the core layer. It is necessary to improve the recording density.

Conventionally, NiFe alloys have been frequently used as the magnetic material. The NiFe alloy was formed by plating using an electroplating method using a direct current, and a saturation magnetic flux density Bs of about 1.8 T could be obtained.

[0004]

In order to further increase the saturation magnetic flux density Bs of the NiFe alloy, for example, an electroplating method using a pulse current is used instead of an electroplating method using a direct current.

This makes it possible to increase the Bs of the NiFe alloy. However, even in such a case, the saturation magnetic flux density Bs only increases to about 1.9 T at most,
It was very difficult to obtain a saturation magnetic flux density Bs higher than T.

[0006] When the saturation magnetic flux density Bs is increased, the surface roughness of the film surface becomes severe, and the NiFe alloy is eroded by various solvents used in the process of manufacturing the thin film magnetic head.

A magnetic material often used other than the NiFe alloy includes a CoFe alloy.
Conventionally, the Co content in the CoFe alloy is about 50% by mass, and in such a composition ratio, the saturation magnetic flux density Bs is small, and the surface roughness on the film surface is severe and the corrosion resistance is low. .

Accordingly, the present invention has been made to solve the above-mentioned conventional problems. By optimizing the composition ratio of the CoFe alloy, the saturation magnetic flux density Bs is higher than the saturation magnetic flux density Bs of the NiFe alloy, and corrosion resistance is improved. It is an object of the present invention to provide a soft magnetic film excellent in the above, a thin film magnetic head using the soft magnetic film, a method for manufacturing the soft magnetic film, and a method for manufacturing the thin film magnetic head.

[0009]

The composition of the first soft magnetic film according to the present invention is represented by Co _1-x Fe _X , and the composition ratio X of Fe is not less than 50% by mass and not more than 90% by mass. And are formed by plating.

[0010] Within the above composition range of the CoFe alloy, the saturation magnetic flux density Bs can be made 2.0T or more. In addition, coarsening of the crystal grain size is suppressed, and crystals are formed densely, and the surface roughness of the film surface can be reduced. Therefore, in the present invention, a high saturation magnetic flux density Bs of 2.0 T or more can be obtained, and at the same time, a soft magnetic film having excellent corrosion resistance can be manufactured.

In the present invention, the composition ratio of Fe is 6
It is preferable that the content be 0% by mass or more and 78% by mass or less.
Thereby, the saturation magnetic flux density Bs can be set to 2.25T or more.

Further, in the present invention, the composition ratio of Fe is as follows:
More preferably, it is 65% by mass or more and 75% by mass or less. Thereby, the saturation magnetic flux density Bs can be set to 2.3T or more.

In the present invention, the center line average roughness Ra of the film surface of the soft magnetic film can be set to 9 nm or less. In the present invention, the center line average roughness Ra is more preferably 5 nm or less.

Further, the coercive force Hc can be reduced by suppressing the increase in the crystal grain size and the surface roughness of the film surface.

The composition of the second soft magnetic film of the present invention is represented by Co _1-x Fe _x , and the composition ratio X of Fe is 68
It is not less than 80% by mass and not more than 80% by mass, and is formed by plating.

The saturation magnetic flux density Bs can be set to 2.0 T or more within the above-mentioned composition range of the CoFe alloy. In addition, coarsening of the crystal grain size is suppressed, and crystals are formed densely, and the surface roughness of the film surface can be reduced. Therefore, in the present invention, a high saturation magnetic flux density Bs of 2.0 T or more can be obtained, and at the same time, a soft magnetic film having excellent corrosion resistance can be manufactured. In the present invention, the saturation magnetic flux density Bs
Is preferably 2.25T or more.

In the present invention, the center line average roughness Ra of the film surface of the soft magnetic film can be set to 9 nm or less.

The present invention also provides a thin film having a lower core layer made of a magnetic material, an upper core layer formed on the lower core layer via a magnetic gap, and a coil layer for applying a recording magnetic field to both core layers. In the magnetic head, at least one of the core layers is formed of the soft magnetic film described above.

In the present invention, it is preferable that a lower magnetic pole layer is formed on the lower core layer so as to protrude at a surface facing the recording medium, and the lower magnetic pole layer is formed of the soft magnetic film.

Further, the thin film magnetic head according to the present invention comprises:
A lower core layer and an upper core layer, and a magnetic pole portion located between the lower core layer and the upper core layer and having a width dimension in the track width direction regulated to be shorter than that of the lower core layer and the upper core layer. The magnetic pole portion includes a lower magnetic pole layer continuous with the lower core layer, an upper magnetic pole layer continuous with the upper core layer, and a gap layer located between the lower magnetic pole layer and the upper magnetic pole layer. The portion is composed of an upper magnetic pole layer continuous with an upper core layer, and a gap layer located between the upper magnetic pole layer and the lower magnetic core layer, wherein the upper magnetic pole layer and / or the lower magnetic pole layer are as described above. Characterized by being formed of a soft magnetic film formed.

In the present invention, at least a portion of the core layer adjacent to the magnetic gap is composed of two or more magnetic layers, or the pole layer is composed of two or more magnetic layers. It is preferable that a magnetic layer in contact with a magnetic gap is formed by the soft magnetic film.

Further, in the present invention, the other magnetic layer other than the magnetic layer in contact with the magnetic gap is formed of a CoFe alloy, and the composition ratio of Fe in the other magnetic layer is determined by the magnetic ratio of the magnetic layer on the side in contact with the magnetic gap layer. It is preferable that the composition ratio of Fe in the layer is smaller than X.

As described above, the CoFe alloy as the soft magnetic film in the present invention has a high saturation magnetic flux density Bs of 2.0 T or more and a small surface roughness. By using such a soft magnetic film as the core material of the thin-film magnetic head, it is possible to concentrate the magnetic flux near the gap, promote high recording density, and provide a thin-film magnetic head with excellent corrosion resistance. It is possible to manufacture.

In the method for producing a soft magnetic film according to the present invention, the ratio of Fe ion concentration / Co ion concentration in a plating bath containing no saccharin sodium is set to 1.0 or more and 17.0 or less, Co _1-X Fe _X is formed by plating, wherein the composition ratio X of Fe is 50% by mass or more and 90% by mass or less by plating.

As described above, in the present invention, a CoFe alloy is formed by plating using an electroplating method using a pulse current. In the electroplating method using a pulse current, for example, ON / OFF of a current control element is repeated, and a time for flowing a current and a blank time for not flowing a current are provided during plating.
By providing a time during which no current flows, CoF
The e-alloy film is formed by plating little by little, and it is possible to alleviate the bias of the current density distribution during plating as compared with the electroplating method using a direct current. According to the electroplating method using a pulse current, the content of Fe contained in the soft magnetic film can be easily adjusted as compared with the electroplating method using a direct current, and a large amount of the Fe content can be incorporated into the film.

Next, in the present invention, the composition of the plating bath is optimized as described above. In the present invention, as described above, the ratio of Fe ion concentration / Co ion concentration in the plating bath is set to 1.0.
Above, it is defined as 17.0 or less. As a result, as shown in the experimental results described later, the composition ratio of the CoFe alloy can be set to 50% by mass or more and 90% by mass or less, the saturation magnetic flux density is as high as 2.0T or more, and the center line of the film surface is determined. It is possible to plate a CoFe alloy having an average roughness Ra as small as 9 nm or less.

In the present invention, saccharin sodium is not mixed in the plating bath. The saccharin sodium (C ₆ H ₄ CONNaSO ₂ ) has a role as a stress relaxing agent, and is generally mixed in a plating bath.

However, according to the present invention, this saccharin sodium is not mixed into the plating bath, so that
The Fe composition ratio of the soft magnetic film made of Fe is set to 2.0 over a very wide composition range of 50 mass% or more and 90 mass% or less.
This makes it possible to obtain a high saturation magnetic flux density Bs of T or more. It was also found that the center line average roughness Ra of the film surface could be suppressed to a low value of 9.0 nm or less over a wider composition range than that in the case where sodium saccharin was mixed.

As described above, according to the present invention, the soft magnetic film made of a CoFe alloy is formed so that the ratio of the Fe concentration in the plating bath to the Co ion concentration is within a predetermined range, and no saccharin sodium is mixed in the plating bath. By forming a CoFe alloy by plating using an electroplating method using a pulse current, a soft magnetic film having a high saturation magnetic flux density Bs and excellent corrosion resistance can be manufactured.

In the method for producing a soft magnetic film according to the present invention, the ratio of Fe ion concentration / Co ion concentration in a plating bath containing no saccharin sodium is adjusted to 1.0 or more and 10.0 or less, The plating method is characterized in that Co _1-x Fe _X whose Fe composition ratio X is 60% by mass or more and 78% by mass or less is formed by plating.

Alternatively, in the method of manufacturing a soft magnetic film according to the present invention, the ratio of Fe ion concentration / Co ion concentration in a plating bath containing no saccharin sodium is adjusted to 3.0 or more and 8.0 or less, The plating method is characterized in that Co _1-x Fe _X is formed by plating in which the composition ratio X of Fe is 65% by mass or more and 75% by mass or less by plating.

Alternatively, the method for producing a soft magnetic film according to the present invention is characterized in that F in a plating bath mixed with saccharin sodium.
The ratio of e ion concentration / Co ion concentration is set to 1.5 or more and 2.5 or less, and Co _1-X is used in which the Fe composition ratio X becomes 68% or more and 80% or less by electroplating using a pulse current. It is characterized in that Fe _X is formed by plating.

In the present invention, saccharin sodium is mixed in the plating bath. When saccharin sodium is mixed in, the saturation magnetic flux density Bs tends to decrease as compared with the case where saccharin sodium is not mixed. This makes it possible to produce a soft magnetic film having a saturation magnetic flux density Bs of 2.0 T or more and excellent corrosion resistance.

In the present invention, the plating bath contains
It is preferable to mix butyne-1,4 diol. As a result, coarsening of the crystal grain size of the plated CoFe alloy is suppressed, and since the crystal grain size is reduced, voids are less likely to be generated between the crystals, and the surface roughness of the film surface is suppressed. Since the surface roughness can be suppressed, the coercive force Hc can be reduced.

In the present invention, it is preferable that sodium 2-ethylhexyl sulfate is mixed in the plating bath. As a result, hydrogen generated in the plating bath is removed by sodium 2-ethylhexyl sulfate, which is a surfactant, and surface roughness due to the adhesion of the hydrogen to the plating film can be suppressed.

Although sodium lauryl sulfate may be used in place of the sodium 2-ethylhexyl sulfate, the use of sodium 2-ethylhexyl sulfate is more preferable.
There is little bubbling when mixed into the plating bath, so that a large amount of the sodium 2-ethylhexyl sulfate can be mixed into the plating bath, and the hydrogen can be more appropriately removed.

According to the present invention, there is provided a lower core layer made of a magnetic material, an upper core layer facing the lower core layer via a magnetic gap on a surface facing the recording medium, and a recording magnetic field is induced in both core layers. In a method of manufacturing a thin-film magnetic head having a coil layer, at least one of the core layers is formed by plating with a soft magnetic film by the manufacturing method described above.

Further, in the present invention, it is preferable that a lower magnetic pole layer is formed so as to protrude on the lower core layer at a surface facing the recording medium, and the lower magnetic pole layer is formed by plating with the soft magnetic film.

Further, in the method of manufacturing a thin film magnetic head according to the present invention, the lower core layer and the upper core layer may be located between the lower core layer and the upper core layer and have a width dimension in the track width direction. And a magnetic pole portion regulated to be shorter than the upper core layer, wherein the magnetic pole portion is a lower magnetic pole layer continuous with the lower core layer, an upper magnetic pole layer continuous with the upper core layer, and the lower magnetic pole layer and the upper magnetic layer. Formed with a gap layer located between the pole layers, or the magnetic pole portion is formed of an upper pole layer continuous with the upper core layer, and a gap layer located between the upper pole layer and the lower core layer, At this time, the upper magnetic pole layer and / or the lower magnetic pole layer is formed by plating with a soft magnetic film by the manufacturing method described above.

In the present invention, the core layer may be formed of two or more magnetic layers at least in a portion adjacent to the magnetic gap, or the pole layer may be formed of two or more magnetic layers. It is preferable that a magnetic layer in contact with the magnetic gap among the layers is formed by plating with the soft magnetic film.

In the present invention, the magnetic layer other than the magnetic layer in contact with the magnetic gap is formed of a CoFe alloy,
At this time, it is preferable that the composition ratio of Fe in the other magnetic layer is smaller than the composition ratio X of Fe in the magnetic layer on the side in contact with the magnetic gap layer.

As described above, the ratio of Fe ion concentration / Co ion concentration in a plating bath containing no saccharin sodium was determined by electroplating a soft magnetic film according to the present invention as a soft magnetic film using a pulse current. By performing plating by setting the value to 1.0 or more and 17.0 or less, the Fe composition ratio of the CoFe alloy can be set to 50% to 90% by mass.

By using such a soft magnetic film as a core material of a thin-film magnetic head, the saturation magnetic flux density Bs is as high as 2.0 T or more, and a high recording density can be achieved, and the corrosion resistance is excellent. It is possible to manufacture a thin film magnetic head with good yield.

[0044]

FIG. 1 is a partial front view of a thin-film magnetic head according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view of the thin-film magnetic head shown in FIG. It is a longitudinal cross-sectional view.

The thin-film magnetic head according to the present invention is formed on the trailing end face 11a of the slider 11 made of a ceramic material constituting a floating head. The MR head h1 and the inductive head h2 for writing are laminated. Thus, a combined MR / inductive thin film magnetic head (hereinafter simply referred to as a thin film magnetic head) is obtained.

The MR head h1 uses the magnetoresistance effect to detect a leakage magnetic field from a recording medium such as a hard disk and read a recording signal.

As shown in FIG. 2, an N ₂ film is formed on the trailing side end surface 11a of the slider 11 via an Al ₂ O ₃ film 12.
A lower shield layer 13 made of a magnetic material made of iFe or the like is formed, and a lower gap layer 1 made of an insulating material is further formed thereon.
4 are formed.

On the lower gap layer 14, an anisotropic magnetoresistive (AMR) element and a giant magnetoresistive effect (G) are arranged in the height direction (Y direction in the figure) from the surface facing the recording medium.
MR) element or tunnel type magnetoresistive effect (TMR)
A magnetoresistive element 10 such as an element is formed, and an upper gap layer 15 made of an insulating material is formed on the magnetoresistive element 10 and the lower gap layer 14. Further, an upper shield layer 16 made of a magnetic material such as NiFe is formed on the upper gap layer 15.
The MR head h1 is composed of a laminated film from the lower shield layer 13 to the upper shield layer 16.

Next, in the embodiment shown in FIGS. 1 and 2, the upper shield layer 16 is also used as a lower core layer of the inductive head h2, and a Gd determining layer 17 is formed on the lower core layer 16. The gap depth (Gd) is regulated by the length from the surface facing the recording medium to the tip of the Gd determining layer 17. The Gd determining layer 17
Is formed of, for example, an insulating material.

As shown in FIG. 1, the upper surface 16a of the lower core layer 16 is formed as an inclined surface that inclines toward the lower surface as the distance from the base end of the magnetic pole portion 18 in the track width direction (X direction in the drawing) increases. Thus, it is possible to suppress the occurrence of side fringing.

As shown in FIG. 2, a magnetic pole portion 18 is formed from the surface facing the recording medium to the Gd determining layer 17.

The magnetic pole portion 18 includes a lower magnetic pole layer 19 from below.
A non-magnetic gap layer 20 and an upper magnetic pole layer 21 are stacked.

The lower magnetic pole layer 19 is formed by plating directly on the lower core layer 16. The lower magnetic pole layer 19
It is preferable that the gap layer 20 formed thereon is formed of a non-magnetic metal material that can be formed by plating. Specifically, NiP, NiPd, NiW, NiMo, Au,
It is preferably selected from one or more of Pt, Rh, Pd, Ru, and Cr.

As a specific embodiment of the present invention, NiP is used for the gap layer 20. NiP
This is because the gap layer 20 can be appropriately brought into a non-magnetic state by forming the gap layer 20 in this manner.

Further, the upper magnetic pole layer 21 formed on the gap layer 20 has the upper core layer 2 formed thereon.
2 is magnetically connected.

When the gap layer 20 is formed of a non-magnetic metal material which can be formed by plating as described above, the lower magnetic pole layer 1
9, the gap layer 20 and the upper magnetic pole layer 21 can be formed by continuous plating.

The magnetic pole portion 18 may be composed of two layers, a gap layer 20 and an upper magnetic pole layer 21.

As shown in FIG. 1, the magnetic pole portion 18 has a track width Tw in the track width direction (X direction in the drawing).

As shown in FIG. 1 and FIG.
An insulating layer 23 is formed on both sides in the track width direction (X direction in the drawing) and behind the height direction (Y direction in the drawing). The upper surface of the insulating layer 23 is flush with the upper surface of the magnetic pole portion 18.

As shown in FIG. 2, a coil layer 24 is spirally patterned on the insulating layer 23. The coil layer 24 is covered with an insulating layer 25 made of organic insulation.

As shown in FIG. 2, the upper core layer 22 is patterned from the magnetic pole portion 18 to the insulating layer 25 by, for example, frame plating. As shown in FIG. 1, the leading end 22a of the upper core layer 22 has a width T1 in the track width direction on the surface facing the recording medium, and the width T1 is larger than the track width Tw. Have been.

As shown in FIG. 2, the upper core layer 2
The second base end 22 b is directly connected to a connection layer (back gap layer) 26 made of a magnetic material and formed on the lower core layer 16.

In the present invention, the upper magnetic pole layer 21 and / or the lower magnetic pole layer 19 are formed of a soft magnetic film having the following composition ratio. (1) The composition formula is represented by Co _1-x Fe _x , and the Fe composition ratio X
Is a soft magnetic film which is not less than 50% by mass and not more than 90% by mass and is formed by plating.

As described above, in the present invention, the Fe content X is set to 50% by mass or more and 90% by mass or less.

The reason why the Fe content X is set within the above range is that the saturation magnetic flux density Bs can be set to 2.0 T or more. Preferably, the composition ratio of the Fe is 60% by mass or more and 78% by mass or less, and in such a case, the saturation magnetic flux density Bs can be set to 2.25T or more. More preferably, the composition ratio of Fe is not less than 65% by mass and not less than 75% by mass.
In such a case, the saturation magnetic flux density Bs is set to 2.3T.
More than that.

The value of the above-mentioned saturation magnetic flux density is larger than that of the NiFe alloy, and in the present invention, a high saturation magnetic flux density can be stably obtained.

Incidentally, as described later in detail, the soft magnetic film described above does not contain sodium saccharin (C ₆ H ₄ CONNaSO ₂ ) as a stress relaxing agent in the plating bath, and the Fe ion concentration in the plating bath is reduced. Is set within a predetermined range, and the plating bath is formed by electroplating using a pulse current.

According to the experiment described later, the saturation flux density Bs of CoFe can be improved as compared with the case where the saccharin sodium is not mixed in the plating bath, and especially by optimizing the composition ratio of Fe. It is possible to obtain a very high saturation magnetic flux density Bs of 2.3T or more.

It is considered that the reason why the saturation magnetic flux density Bs is improved by not mixing the saccharin sodium is that Fe ions enter and exit from the plating surface and a dense film can be formed.

When saccharin sodium is not mixed in the plating bath, the film stress and the like tend to be larger than in the case where saccharin is mixed, but the value of the film stress is in a range that cannot be used as the pole layers 19 and 21 shown in FIG. On the other hand, on the other hand, the saturation magnetic flux density Bs required to promote a higher recording density in the future can be 2.0 T or more over a wide composition range of Fe, or 2.3 T or more depending on the Fe composition.

Accordingly, the lower magnetic pole layer 19 and / or the upper magnetic pole layer 21 with the above composition ratio of CoF
By using an e-alloy, magnetic flux can be concentrated near the gap, and a thin-film magnetic head capable of coping with high recording density can be obtained.

In addition, when the composition is within the above range, the crystals are formed densely, so that the surface roughness of the film surface can be suppressed and the corrosion resistance can be improved. Therefore, it is possible to prevent corrosion of various solvents used in manufacturing the thin-film magnetic head. In the present invention, the center line average roughness (Ra) of the film surface of the CoFe alloy film can be set to 9 nm or less. Preferably, the center line average roughness (Ra)
Can be set to 5 nm or less.

The reason why the center line average roughness Ra can be suppressed to a small value is that the saccharin sodium is not mixed in the plating bath, and the plated CoFe
It is considered that the element S, which lowers the corrosion resistance, does not enter the inside, and the crystal grain size becomes small and a dense film is formed. The average roughness Ra can be reduced, and the corrosion resistance can be appropriately improved.

In the present invention, the coercive force Hc is set to 237
0 (A / m) or less.

In the present invention, the specific resistance is 17 (μΩ · c).
m) or more. The film stress is 1200M
Pa or less, preferably 400 MPa or less. Further, with respect to the anisotropic magnetic field Hk, an anisotropic magnetic field Hk comparable to that of a NiFe alloy conventionally generally used as a soft magnetic material can be obtained. (2) A soft magnetic film characterized in that the composition formula is represented by Co _1-x Fe _x , the composition ratio X of Fe is not less than 68% by mass and not more than 80% by mass, and is formed by plating.

This soft magnetic film is different from the soft magnetic film of (1) in that saccharin sodium (C ₆ H ₄ CONNaSO ₂ ) serving as a stress relaxing agent is mixed in the plating bath to reduce the Fe ion concentration in the plating bath. The ratio to the Co ion concentration is set within a predetermined range, and plating is performed from this plating bath by electroplating using a pulse current.

According to the experiment described later, even when saccharin sodium is mixed in the plating bath, the composition ratio of Fe is adjusted to be 2.0 T or more, preferably 2.25 T.
The above high saturation magnetic flux density Bs can be obtained.

When saccharin sodium is mixed in the plating bath, the Fe composition range in which a saturation magnetic flux density Bs of 2.0 T or more can be obtained is smaller than in the case where saccharin sodium is not mixed, but the saturation magnetic flux is higher than that of the conventional NiFe alloy The use of the CoFe alloy according to the present invention makes it possible to manufacture a thin-film magnetic head that can appropriately cope with a future increase in recording density.

Further, by mixing saccharin sodium into the plating bath, the film stress can be effectively reduced as compared with the case where it is not mixed.

Further, when the composition is within the above range, the crystals are formed densely, so that the surface roughness of the film surface can be suppressed and the corrosion resistance can be improved. Therefore, it is possible to prevent corrosion of various solvents used in manufacturing the thin-film magnetic head. In the present invention, the center line average roughness (Ra) of the film surface of the CoFe alloy film can be set to 9 nm or less.

In the present invention, the coercive force Hc is set to 158
0 (A / m) or less.

In the present invention, the specific resistance is 25 (μΩ · c).
m) or more. In addition, the film stress is 400MP.
a. Further, with respect to the anisotropic magnetic field Hk, an anisotropic magnetic field Hk comparable to that of a NiFe alloy conventionally generally used as a soft magnetic material can be obtained.

The CoFe alloy (1) or (2) can be used for other types of thin-film magnetic heads.

FIG. 3 is a partial front view showing the structure of a thin-film magnetic head according to a second embodiment of the present invention. FIG. 4 is a longitudinal section of the thin-film magnetic head taken along line 4-4 shown in FIG. FIG.

In this embodiment, the structure of the MR head h1 is the same as in FIGS. As shown in FIG. 3, on the lower core layer 16, an insulating layer 31 is formed. In the insulating layer 31, a track width forming groove 31a having a predetermined length is formed rearward in the height direction (Y direction in the drawing) from the surface facing the recording medium. The track width forming groove 31a has a track width Tw on the surface facing the recording medium.
(See FIG. 3).

In the track width forming groove 31a, a magnetic pole portion 30 in which a lower magnetic pole layer 32, a nonmagnetic gap layer 33, and an upper magnetic pole layer 34 are laminated from below is formed.

The lower magnetic pole layer 32 is formed by plating directly on the lower core layer 16. The lower magnetic pole layer 32
The gap layer 33 formed thereon is preferably formed of a non-magnetic metal material that can be formed by plating. Specifically, NiP, NiPd, NiW, NiMo, Au,
It is preferably selected from one or more of Pt, Rh, Pd, Ru, and Cr.

As a specific embodiment of the present invention, NiP is used for the gap layer 33. NiP
This is because the gap layer 33 can be appropriately brought into a non-magnetic state by forming the gap layer 33.

The magnetic pole portion 30 may be composed of two layers, a gap layer 33 and an upper magnetic pole layer 34.

On the gap layer 33, a Gd determining layer 37 is formed from a position away from the surface facing the recording medium by a gap depth (Gd) and onto the insulating layer 31.

Further, the upper pole layer 34 formed on the gap layer 33 is formed on the upper core layer 4 formed thereon.
0 and magnetically connected.

As described above, when the gap layer 33 is formed of a non-magnetic metal material that can be formed by plating, the lower magnetic pole layer 3
2. The gap layer 33 and the upper pole layer 34 can be formed by continuous plating.

As shown in FIG. 4, a coil layer 38 is spirally patterned on the insulating layer 31. The coil layer 38 is made of an insulating layer 3 made of an organic insulating material or the like.
9.

As shown in FIG. 3, the track width regulating groove 31
On both side end surfaces in the track width direction (X direction in the drawing) of FIG. , 31c are formed.

As shown in FIG. 3, the tip portion 40a of the upper core layer 40 is formed in a direction away from the lower core layer 16 from the upper surface of the upper magnetic pole layer 34 to the inclined surfaces 31c, 31c.

As shown in FIG. 4, the upper core layer 40
The base end portion 40b of the upper core layer 40 is formed directly on the lower core layer 16 from the surface facing the recording medium in the height direction (Y direction in the drawing).

In the second embodiment shown in FIGS. 3 and 4, the lower magnetic pole layer 32 and / or the upper magnetic pole layer 34 are formed of the above-mentioned (1) or (2) CoFe alloy.

The lower magnetic pole layer 32 and the upper magnetic pole layer 34 are formed of the above-mentioned CoFe alloy having a high saturation magnetic flux density Bs of 2.0 T or more, preferably 2.25 T or more, more preferably 2.3 T or more. As a result, the magnetic flux can be concentrated near the gap, and the recording density can be improved. Therefore, it is possible to manufacture a thin-film magnetic head excellent in increasing the recording density.

The CoFe alloy is formed within the above composition range, so that the crystals are formed densely, the surface roughness on the film surface can be suppressed, and the corrosion resistance can be improved. In the present invention, the center line average roughness Ra of the film surface can be set to 9 nm or less. More preferably, it is 5 nm or less. Further, the coercive force Hc can be reduced.

In the embodiments shown in FIGS. 1 to 4, each of the magnetic heads has the magnetic pole portions 18 and 30 between the lower core layer 16 and the upper core layers 22 and 40. 19, 32 and / or upper pole layer 21, 34
Is formed of the CoFe alloy of the above (1) or (2), but in the present invention, the lower magnetic pole layers 19, 3
The two and / or upper magnetic pole layers 21 and 34 may be configured by laminating two or more magnetic layers. In such a configuration, it is preferable that the magnetic layer in contact with the gap layers 20 and 33 be formed of a CoFe alloy having the above composition range. As a result, the magnetic flux can be more concentrated in the vicinity of the gap, and it is possible to manufacture a thin-film magnetic head capable of coping with a future increase in recording density.

The magnetic layers other than the magnetic layers in contact with the gap layers 20 and 33 are formed of a CoFe alloy.
Is preferably smaller than the Fe composition ratio of the magnetic layer in contact with the magnetic layer. As a result, the saturation magnetic flux density Bs of the magnetic layer in contact with the gap layers 20 and 33 can be higher than that of the other magnetic layers, and the magnetic flux can be more appropriately concentrated near the gap. The other magnetic layer need not be formed of a CoFe alloy, but may be formed of, for example, a NiFe alloy. In such a case, the Fe content of the NiFe alloy is
The amount of CoFe of the magnetic layer on the side in contact with the gap layers 20 and 33 may be larger than the Fe amount. As will be shown in an experiment described later, in the case of a NiFe alloy, the saturation magnetic flux density Bs is about 1.9 T at most even when the Fe content is about 73% by mass, and does not exceed 2.0 T.
This is because Bs of the magnetic layer on the 0,33 side can be made higher.

It is preferable that the saturation magnetic flux density Bs of the lower magnetic pole layers 19 and 32 is high. However, by lowering the saturation magnetic flux density Bs of the upper magnetic pole layers 21 and 34, the gap between the lower magnetic pole layer and the upper magnetic pole layer is reduced. If the leakage magnetic field is easily inverted, the writing density of signals on the recording medium can be further increased.

The lower core layer 16 and the upper core layer 22,
40 may be formed of a CoFe alloy having the above composition range, but in such a case, the saturation magnetic flux density Bs of the upper magnetic pole layers 21 and 34 and the lower magnetic pole layers 19 and 32 is higher than that of the lower core layer 16.
And CoF so as to be higher than the upper core layers 22 and 40.
It is preferable to appropriately adjust the Fe composition ratio of the e alloy.

FIG. 5 is a longitudinal sectional view of a thin-film magnetic head according to a third embodiment of the present invention. In this embodiment, the MR head h1 is the same as in FIG. As shown in FIG. 5, a magnetic gap layer (nonmagnetic material layer) 41 made of alumina or the like is formed on the lower core layer 16. Further, on the magnetic gap layer 41, there is provided a coil layer 44 patterned so as to be spiral in a plane via an insulating layer 43 made of polyimide or a resist material. The coil layer 44 is formed of a non-magnetic conductive material having a small electric resistance such as Cu (copper).

Further, the coil layer 44 is surrounded by an insulating layer 45 made of polyimide or a resist material, and an upper core layer 46 made of a soft magnetic material is formed on the insulating layer 45.

As shown in FIG. 5, the tip 46a of the upper core layer 46 faces the lower core layer 16 via the magnetic gap layer 41 on the surface facing the recording medium. A magnetic gap of Gl1 is formed, and the base end 46b of the upper core layer 46 is magnetically connected to the lower core layer 16, as shown in FIG.

In the present invention, the lower core layer 16 and / or the upper core layer 46 may be made of the above-mentioned (1) or (2) Co.
It is formed of an Fe alloy. C formed at this composition ratio
The oFe alloy can obtain a saturation magnetic flux density Bs of 2.0 T or more, preferably 2.25 T or more, more preferably 2.3 T or more.

Upper core layer 46 and / or lower core layer 1
6 is made of the above-mentioned CoFe alloy having a high saturation magnetic flux density Bs of 2.0 T or more, the magnetic flux can be concentrated near the gap, and the recording density can be improved. This makes it possible to manufacture a thin-film magnetic head that is excellent in structure.

Further, when the CoFe alloy is formed within the above composition range, crystals are formed densely, surface roughness on the film surface can be suppressed, and corrosion resistance can be improved. In the present invention, the center line average roughness Ra of the film surface can be set to 9 nm or less. Preferably, it can be set to 5 nm or less. Further, the coercive force Hc can be reduced.

When the CoFe alloy is within the above composition range, it is 17 (μΩ · cm) or more, preferably 25 (μΩ · cm).
cm) or more. Further, the film stress can be made 1200 MPa or less, preferably 400 MPa or less. Further, with respect to the anisotropic magnetic field Hk, an anisotropic magnetic field Hk comparable to that of a NiFe alloy conventionally generally used as a soft magnetic material can be obtained.

FIG. 6 is a longitudinal sectional view of a thin-film magnetic head according to a fourth embodiment of the present invention. The difference from FIG. 5 is that the upper core layer 46 is formed by laminating two magnetic layers.

The upper core layer 46 is composed of a high Bs layer 47 having a high saturation magnetic flux density Bs and an upper layer 4 laminated thereon.
8.

The high Bs layer 47 is formed of the CoFe alloy (1) or (2).

As a result, the saturation magnetic flux density Bs of the high Bs layer 47 can be set to 2.0 or more, preferably 2.25 T or more, and more preferably 2.3 T or more.

The above (1) or (2) CoFe
In the high Bs layer 47 made of an alloy, since the crystal is formed densely, the surface roughness of the film surface of the high Bs layer 47 can be reduced, and therefore, the corrosion resistance can be improved, and the coercive force Hc can be reduced. Can be smaller. Specifically, the center line average roughness Ra of the film surface can be made 9 nm or less, preferably 5 nm or less, and the coercive force Hc becomes 2370 (A /
m) or less, and preferably 1580 (A / m) or less. Further, when a CoFe alloy is used, the specific resistance is 17 (μΩ · cm) or more, preferably 25 (μΩ · cm).
(ΜΩ · cm) or more. The film stress is 1200M
Pa or less, and preferably 400 MPa or less.

An upper layer 48 constituting the upper core layer 46
Although the saturation magnetic flux density Bs is smaller than that of the high Bs layer 47, the specific resistance is higher than that of the high Bs layer 47. The upper layer 48 is formed of a CoFe alloy,
In this case, the Fe content of the upper layer 48 is
Is preferably smaller than the amount of Fe. Thereby, the high Bs layer 47 has a higher saturation magnetic flux density Bs than the upper layer 48, and the magnetic flux can be concentrated near the gap to improve the recording resolution. The upper layer 48
Need not be formed of a CoFe alloy, for example, NiF
It may be formed of an e-alloy. In such a case, the Fe amount of the NiFe alloy may be larger than the Fe amount of CoFe of the high Bs layer 47. As shown in the experiments described below, Ni
In the case of an Fe alloy, the saturation magnetic flux density Bs is about 1.9 T at most even when the Fe content is about 73% by mass, and does not exceed 2.0 T. Therefore, Bs on the high Bs layer 47 side can be made higher. Because it is possible.

Further, since the upper core layer 46 is provided with the upper layer 48 having a high specific resistance, it is possible to reduce the loss due to the eddy current generated by the increase in the recording frequency. A compatible thin film magnetic head can be manufactured. As shown in the experimental results described later, the NiFe alloy can have a higher specific resistance than the CoFe alloy. Therefore, it is preferable to use the NiFe alloy for the upper layer 48 rather than the CoFe alloy.

In the present invention, as shown in FIG.
It is preferable that the layer 47 is formed on the lower layer side facing the gap layer 41. Further, the high Bs layer 47 is provided at the tip end 46 a of the upper core layer 46 directly in contact with the gap layer 41.
Only it may be formed.

The lower core layer 16 may also be composed of two layers, a high Bs layer and a high resistivity layer. In such a configuration, a high Bs layer is laminated on the high resistivity layer, and the high Bs layer is formed.
The layer faces the upper core layer 46 via the gap layer 41.

In the embodiment shown in FIG. 6, the upper core layer 46 has a two-layer structure, but may have three or more layers. In the case of such a configuration, the high Bs layer 47 is preferably formed on the side in contact with the magnetic gap layer 41.

FIG. 7 is a longitudinal sectional view of a thin-film magnetic head according to a fifth embodiment of the present invention. In the embodiment of FIG.
The configuration of the head h1 is the same as that of FIG. As shown in FIG. 7, a lower magnetic pole layer 50 is formed on the lower core layer 16 so as to protrude from the surface facing the recording medium. An insulating layer 51 is formed behind the lower magnetic pole layer 50 in the height direction (Y direction in the drawing). The upper surface of the insulating layer 51 has a concave shape, and a coil forming surface 51a is formed.

From above the lower magnetic pole layer 50, the insulating layer 51
A gap layer 52 is formed upward. Further, a gap layer 5 is formed on the coil forming surface 51a of the insulating layer 51.
2, a coil layer 53 is formed. The coil layer 53 is covered with an insulating layer 54 made of organic insulation.

As shown in FIG. 7, the upper core layer 55 is patterned from the gap layer 52 to the insulating layer 54 by, for example, frame plating.

The tip 55a of the upper core layer 55 is formed on the gap layer 52 so as to face the lower magnetic pole layer 50. A base end 55b of the upper core layer 55 is magnetically connected to the lower core layer 16 via a lifting layer 56 formed on the lower core layer 16.

In this embodiment, the upper core layer 55
And / or the lower magnetic pole layer 50 is formed of the CoFe alloy (1) or (2) described above.

In FIG. 7, when the lower magnetic pole layer 50 is formed and the lower magnetic pole layer 50 is formed of the CoFe alloy having a higher saturation magnetic flux density Bs than the lower core layer 16, the magnetic flux is concentrated near the gap. Thus, the recording density can be improved.

Further, the upper core layer 55 is entirely
The upper core layer 55 may have a laminated structure of two or more magnetic layers as in FIG. 6, and the side facing the gap layer 52 may serve as a high Bs layer as in the case of FIG. May be formed. In such a case, only the tip portion 55a of the upper core layer 55 is formed in a laminated structure of two or more magnetic layers, and the gap layer 5
It is preferable that the high Bs layer is formed in contact with the upper surface 2 in order to concentrate the magnetic flux near the gap and improve the recording density.

In the present invention, in each of the embodiments shown in FIGS. 1 to 7, the CoFe alloy film is formed by plating. In the present invention, the CoFe alloy can be formed by electroplating using a pulse current.

Further, by forming the CoFe alloy by plating, the CoFe alloy can be formed to have an arbitrary thickness, and can be formed to have a larger thickness than that formed by sputtering.

In each embodiment, the layer denoted by reference numeral 16 is a layer that is used as both a lower core layer and an upper shield layer. However, the lower core layer and the upper shield layer may be formed separately. In such a case, an insulating layer is interposed between the lower core layer and the upper shield layer.

Next, a general method of manufacturing the thin film magnetic head shown in FIGS. 1 to 7 will be described below.

In the thin-film magnetic head shown in FIGS. 1 and 2, after forming the Gd determining layer 17 on the lower core layer 16, the lower magnetic pole layer 19 and the non-magnetic layer are formed in the height direction from the surface facing the recording medium by using a resist. Magnetic gap layer 20 and upper pole layer 21
Is formed by continuous plating. Next, after the insulating layer 23 is formed behind the magnetic pole portion 18 in the height direction, the upper surface of the magnetic pole portion 18 and the upper surface of the insulating layer 23 are flattened using, for example, a CMP technique.
After spirally patterning the coil layer 24 on the insulating layer 23, an insulating layer 25 is formed on the coil layer 24. Then, the upper core layer 22 is formed, for example, by frame plating from the magnetic pole portion 18 to the insulating layer 25.

In the thin-film magnetic head shown in FIGS. 3 and 4, after the insulating layer 31 is formed on the lower core layer 16, the resist is used to direct the insulating layer 31 rearward in the height direction from the surface of the insulating layer 31 facing the recording medium. Then, a track width forming groove 31a is formed.
Further, inclined surfaces 31c, 31c shown in FIG. 3 are formed in the track width forming groove 31a.

A lower magnetic pole layer 32 and a non-magnetic gap layer 33 are formed in the track width forming groove 31a. After a Gd determining layer 37 is formed on the insulating layer 31 from above the gap layer 33, an upper magnetic pole layer 34 is formed on the gap layer 33 by plating. Next, after the coil layer 38 is spirally patterned on the insulating layer 31, an insulating layer 39 is formed on the coil layer 38. Then, the upper core layer 40 is formed from the upper magnetic pole layer 34 to the insulating layer 39 by, for example, a frame plating method.

In the thin-film magnetic head shown in FIGS. 5 and 6, first, a gap layer 41 is formed on the lower core layer 16, an insulating layer 43 is formed, and a coil layer 44 is patterned on the insulating layer 43. Form. After forming the insulating layer 45 on the coil layer 44, the insulating layer 45 is removed from the gap layer 41.
The upper core layer 46 is patterned upward by frame plating.

In the thin-film magnetic head shown in FIG. 7, a lower magnetic pole layer 50 is first formed on the lower core layer 16 using a resist, and an insulating layer 51 is formed behind the lower magnetic pole layer 50 in the height direction. The lower magnetic pole layer 50 and the insulating layer 5
1 is flattened once by a CMP technique, and then the coil forming surface 51a having a concave shape is formed on the upper surface of the insulating layer 51.
To form Next, after a gap layer 52 is formed on the insulating layer 51 from above the lower magnetic pole layer 50, a coil layer 53 is spirally patterned on the gap layer 52, and an insulating layer 54 is formed on the coil layer 53. To form Then, the upper core layer 55 is patterned from the gap layer 52 to the insulating layer 54 by, for example, frame plating.

Next, the method of plating a CoFe alloy in which the composition ratio of Fe is 50% by mass or more and 90% by mass or less in the present invention will be described below.

In the present invention, the CoFe alloy is formed by electroplating using a pulse current.

In the electroplating method using a pulse current, for example, ON / OFF of a current control element is repeated, and a time for flowing a current and a blank time for not flowing a current are provided at the time of plating. By providing a time period in which no current is supplied, the CoFe alloy film is formed by plating little by little, and even if the concentration of Fe ions in the plating bath is increased, compared with the case of using a direct current as in the past, It is possible to alleviate the bias of the current density distribution during plating.

The pulse current is repeatedly turned ON / OFF in a cycle of several seconds, for example, so that the duty ratio is 0.1 to 0.5.
It is preferable to set the degree. The condition of the pulse current is Co
Average grain size and center line average roughness Ra of Fe alloy
Affect.

As described above, in the electroplating method using a pulse current, the bias of the current density distribution during plating can be reduced, and therefore, the Fe content in the CoFe alloy is smaller than that in the electroplating method using a direct current. Can be increased more than before.

Further, in the present invention, the plating bath composition used for forming the CoFe alloy plating is set as follows. In the present invention, the ratio of Fe ion concentration / Co ion concentration is set to 1.0 or more and 17.0 or less. By setting the ratio of the Fe ion concentration to the Co ion concentration in the plating bath to this level, a stirring effect can be obtained and the Fe composition ratio can be increased.

Further, in the present invention, saccharin sodium (C ₆ H ₄ CONNaSO ₂ ) is not mixed in the plating bath. Saccharin sodium is a stress relieving agent and is generally mixed in the plating bath. However, in the present invention, the above-mentioned saccharin sodium is not mixed, so that the entrance and exit of Fe ions can be improved on the plating surface.
The e composition ratio can be increased and a dense film can be formed.

As shown in the experimental results described later, in the case of a CoFe alloy formed under the above conditions, the Fe composition ratio was 50%.
Mass% or more and 90 mass% or less, and the saturation magnetic flux density Bs
Can be set to 2.0T or more, and a high saturation magnetic flux density Bs can be stably obtained.

The center line average roughness Ra of the film surface of the CoFe alloy formed at the above ion concentration ratio can be reduced to 9 nm or less, preferably 5 nm or less, and a soft magnetic film having excellent corrosion resistance can be manufactured. It is possible. In particular, by not mixing saccharin sodium in the plating bath as in the above-described production method, the element S that reduces corrosion resistance is not mixed in the CoFe alloy film, and the crystal grain size is further reduced, and thus the center line of the film surface is reduced. Average roughness Ra is effectively 9 nm
Or less, preferably 5 nm or less.

On the other hand, if the ratio of the ion concentration deviates from the above ratio, that is, if the ratio of Fe ion concentration / Co ion concentration is smaller than 1.0 or larger than 17.0, the saturation magnetic flux density of 2.0 T or more is obtained. May not be obtained, and a high saturation magnetic flux density Bs cannot be obtained stably. Further, the center line average roughness Ra of the film surface is larger than 9 nm, and only a soft magnetic film having poor corrosion resistance can be manufactured.

Further, in the present invention, the Fe ion concentration is as follows.
It is preferably set at 0 g / l or more and 7.5 g / l or less. In the present invention, by setting the Fe ion concentration within this range, the stirring effect can be improved, and the Fe content of the CoFe alloy can be more appropriately increased.

As described above, in the present invention, the electroplating method using a pulse current is used, and the Fe ion concentration in the plating bath /
By setting the ratio of the Co ion concentration to 1.0 or more and 17.0 or less and not mixing saccharin sodium in the plating bath, C having a higher saturation magnetic flux density Bs than before can be obtained.
An oFe alloy can be manufactured. Specifically, B
s can be set to 2.0T or more. Further, the CoFe alloy formed in the above composition range has a dense crystal and a small surface roughness of the film surface, and therefore has a high corrosion resistance and a high coercive force Hc.
A plating film having a small size can be formed.

In the present invention, the ratio of Fe ion concentration / Co ion concentration in the plating bath containing no saccharin sodium is adjusted to 1.0 or more and 10.0 or less, and the composition of Fe is determined by electroplating using a pulse current. Ratio X is 60
It is preferable to form a Co _1-x Fe _x which is not less than 78% by mass but not less than 78% by mass. This makes it possible to effectively obtain a saturation magnetic flux density of 2.25 T or more.

Alternatively, according to the present invention, the Fe ion concentration in the plating bath containing no saccharin sodium / Co
The ratio of the ion concentration is set to 3.0 or more and 8.0 or less, and the Fe composition ratio X is set to 6 by an electroplating method using a pulse current.
It is more preferable to form Co _1-X Fe _X by plating at 5% by mass or more and 75% by mass or less. This makes it possible to effectively obtain a saturation magnetic flux density of 2.3 T or more.

Using a plating bath in which saccharin sodium is not mixed, a CoF
Fe ion concentration / Co
By gradually narrowing the ion concentration ratio as described above, the saturation magnetic flux density Bs is increased to 2.25 T higher than 2.0 T.
It is possible to set the above value or a very high value of 2.3T or more.

The above-mentioned soft magnetic film (1) can be obtained by the method for producing a soft magnetic film without mixing saccharin sodium in the plating bath.

Next, in the present invention, the ratio of Fe ion concentration / Co ion concentration in the plating bath mixed with sodium saccharin was set to 1.5 or more and 2.5 or less, and the Fe composition ratio was determined by electroplating using a pulse current. Co _1-X Fe _{X in} which X is 68% by mass or more and 80% by mass or less can be formed by plating.

The soft magnetic film of the above (2) can be manufactured by this manufacturing method. In this manufacturing method, saccharin sodium is mixed in the plating bath. Saccharin sodium is a stress relieving agent, so that the film stress can be reduced as compared with the case where saccharin sodium is not mixed.

However, when saccharin sodium is mixed in the plating bath, the saturation magnetic flux density Bs tends to be lower than when no saccharin is mixed. However, even when saccharin sodium is mixed in the plating bath, the saturation magnetic flux density Bs becomes 2.0T or more by optimizing the ratio of the Fe ion concentration to the Co ion concentration in the plating bath and the plating method using a pulse current. C having the composition
It becomes possible to form an oFe alloy by plating.

The saturation magnetic flux density Bs is preferably at least 2.25T. Further, the CoFe alloy formed within the above composition range can form a plated film having high corrosion resistance and low coercive force Hc, because the crystal is formed densely and the surface roughness of the film is small. According to the present invention, the center line average roughness Ra of the film surface of the CoFe alloy can be reduced to 9 nm or less, and a soft magnetic film excellent in corrosion resistance can be manufactured.

Next, it is preferable that the following materials are contained in both the plating bath in which sodium saccharin is not mixed and the plating bath in which sodium saccharin is mixed.

In the present invention, in a CoFe alloy plating bath,
It is preferable to mix 2-butyne-1,4 diol. As a result, the crystal grain size of the CoFe alloy can be prevented from becoming coarse, and the coercive force Hc can be reduced.

In the present invention, it is preferable to mix sodium 2-ethylhexyl sulfate in the CoFe alloy plating bath.

The above-mentioned sodium 2-ethylhexyl sulfate is a surfactant. By the incorporation of the sodium 2-ethylhexylsulfate, hydrogen generated at the time of plating of the CoFe alloy can be removed, and the adhesion of the hydrogen to the plating film can be prevented. When hydrogen adheres to the plating film, crystals are not formed densely, and as a result, the surface roughness of the film surface is seriously reduced.Therefore, by removing the hydrogen as in the present invention, the plating film is removed. The surface roughness of the film surface can be reduced, and the coercive force Hc can be reduced.

Although sodium lauryl sulfate may be mixed in place of the sodium 2-ethylhexyl sulfate, the sodium lauryl sulfate is more likely to foam when placed in a plating bath than the sodium 2-ethylhexyl sulfate. It is difficult to mix the sodium lauryl sulfate to such an extent that hydrogen can be effectively removed.
Therefore, in the present invention, sodium 2-ethylhexyl sulfate, which is less liable to foam than sodium lauryl sulfate, can be mixed to the extent that hydrogen can be effectively removed, which is preferable.

Preferably, boric acid is mixed in the plating bath. Boric acid serves as a pH buffering agent on the electrode surface and is effective in providing a glossy plating film.

In the present invention, the thin film magnetic head shown in FIGS. 1 to 7 has been proposed as the use of the CoFe alloy (1) or (2), but the present invention is not limited to this use. For example, the CoFe alloy can be used for a planar magnetic element such as a thin film inductor.

[0164]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a CoFe alloy is formed by plating from a plating bath by using an electroplating method using a pulse current, and the composition ratio is changed while changing the ratio of Fe ion concentration / Co ion concentration in the plating bath. CoFe with different
The alloy was plated.

First, the plating bath composition when the ratio of the Fe ion concentration / Co ion concentration is smaller than 1.5 (Comparative Example 1) is shown in Table 1 below. In addition, saccharin sodium is mixed in the plating bath.

[0166]

[Table 1]

As shown in Table 1, the Fe ion concentration was 4 g /
l. In the experiment, the Fe ion concentration was fixed and the Co ion concentration was 3.0 g / l, 3.4 g / l, and 4.1 g / l.
The CoFe alloy was produced from each plating bath composition while changing the composition to l.

Next, when the ratio of Fe ion concentration / Co ion concentration is 1.5 or more and 2.5 or less (Example), the plating bath composition is shown in Table 2 below. In addition, saccharin sodium is mixed in the plating bath.

[0169]

[Table 2]

As shown in Table 2, the Fe ion concentration was 1.2
It is 3 g / l or 4.0 g / l. In the experiment, the Fe ion concentration was fixed and the Co ion concentration was 0.57 g / l.
(Fe ion is 1.23 g / l), 0.69 g / l (F
e ion is 1.23 g / l) or 1.6 g / l
(In this case, the Fe ion was changed to 4.0 g / l) to produce a CoFe alloy from each plating bath composition.

Finally, when the ratio of Fe ion concentration / Co ion concentration is larger than 2.5 (Comparative Example 2), the plating bath composition ratio is shown in Table 3 below. In addition, saccharin sodium is mixed in the plating bath.

[0172]

[Table 3]

As shown in Table 3, the Fe ion concentration was 4 g /
l. In the experiment, the Fe ion concentration was fixed and the Co ion concentration was 0.11 g / l, 0.34 g / l, 0.57 g / l.
g / l, 0.91 g / l and 1.26 g / l were used to produce CoFe alloys from each plating bath composition.

As shown in Tables 1 to 3, in addition to Fe ions and Co ions, the plating baths contained sodium saccharin, sodium lauryl sulfate, 2-butyne-1,
4-diol, boric acid, and sodium chloride were incorporated in the amounts listed in each table.

Further, from the plating bath compositions shown in Tables 1 to 3, C
When the oFe alloy was formed by plating, the following film forming conditions were used in common.

First, the plating bath temperature was set to 30 ° C. The pH of the electrode was set to 2.8. When the current density is 4
It was set to 6.8 mA / cm2. Furthermore, the duty ratio (ON / OFF) of the pulse current is set to 400/1000 ms.
ec. An Fe electrode was used as the anode electrode.

The soft magnetic properties and film properties of the CoFe alloys formed by plating in the respective plating bath compositions shown in Tables 1 to 3 were as follows.

[0178]

[Table 4]

Table 4 shows the experimental results of Table 1, that is, the experimental results of Comparative Example 1 in which the ratio of the Fe ion concentration / Co ion concentration was smaller than 1.5. As shown in Table 4, the composition ratio of Fe was 59% by mass or more and 67% by mass or less, and the saturation magnetic flux density Bs was 2.25T or less. The saturation magnetic flux density Bs may or may not exceed 2.0T, and the saturation magnetic flux density Bs was unstable. Further, the center line average roughness Ra of the film surface became larger than 9 nm, and the surface roughness became severe.

There are several possible causes of the surface roughness, but the ratio of Fe ion concentration / Co ion concentration is set to 1.
If it is smaller than 5, the amount of Co in the plating solution that touches the cathode (plated side) surface during film formation increases, and the agitation effect decreases, so that the Fe content in the CoFe alloy decreases and the crystal grain size increases. Is likely to be remarkable, and it is expected that the surface roughness will be severe.

[0181]

[Table 5]

Table 5 shows the experimental results of Table 2, that is, the experimental results of Examples in which the ratio of Fe ion concentration / Co ion concentration was 1.5 or more and 2.5 or less. As shown in Table 5, the composition ratio of Fe is not less than 68% by mass and not more than 80% by mass, and the saturation magnetic flux density Bs is 2.3% at not less than 2.25T.
T or less. As described above, when the ratio of the Fe ion concentration / Co ion concentration is set to 1.5 or more and 2.5 or less, the saturation magnetic flux density Bs can always be made larger than 2T. Thus, a saturation magnetic flux density Bs of 2.0 T or more can be obtained stably.

Further, the center line average roughness Ra of the film surface was 9 nm or less, and it was found that surface roughness could be effectively suppressed.

As described above, by setting the ratio of Fe ion concentration / Co ion concentration to 1.5 or more and 2.5 or less, Fe in the plating solution that touches the cathode surface during film formation is smaller than that in Comparative Example 1. Contains a lot, increases the stirring effect, CoF
It is expected that the e-alloy contains a large amount of Fe, the crystal grain size becomes small, a dense film can be formed, and a CoFe alloy having a small saturation magnetic flux density Bs and a small surface roughness can be formed by plating.

[0185]

[Table 6]

Table 6 shows the experimental results of Table 3, that is, the experimental results of Comparative Example 2 in which the ratio of the Fe ion concentration / Co ion concentration was larger than 2.5. As shown in Table 6, the composition ratio of Fe was 83% by mass or more, and the saturation magnetic flux density Bs was 2.2T or less. The saturation magnetic flux density Bs may or may not exceed 2.0T, and the saturation magnetic flux density Bs was unstable. Further, the center line average roughness Ra of the film surface became 10 nm or more, and the surface roughness became severe.

When the ratio of Fe ion concentration / Co ion concentration is larger than 2.5, abnormal precipitation occurs in which Fe is deposited more predominantly than Co. In such a case, the coarsening of the crystal grain size tends to be remarkable. As a result, it is expected that the surface roughness of the film surface becomes severe as well as the saturation magnetic flux density.

Whether the surface roughness can be suppressed or not depends not only on the ratio of the Fe ion concentration / Co ion concentration but also on the magnitude of the Fe ion concentration itself. In the present invention, the Fe ion concentration is 1.0 g / l to 1.5 g / l.
g / l. Conventionally, the Fe ion concentration was about 4.0 g / l. As in the present invention, Fe
By making the ion concentration lower than before, the stirring effect can be increased, the amount of Fe contained in the CoFe alloy can be increased, the crystal grain size can be reduced, and a dense film can be formed. It is possible to suppress surface roughness.

In the case of the examples shown in Table 2, 2-butyne-1,4 diol was mixed in some samples. As a result, coarsening of the crystal grain size of the plated CoFe alloy can be suppressed, and since the crystal grain size is reduced, voids are less likely to be generated between crystals, and the surface roughness of the film surface can be suppressed.

Next, a NiFe alloy is formed by plating from a plating bath having Ni ions and Fe ions by an electroplating method using a pulsed current.
The Ni composition and the soft magnetic properties and film properties of the NiFe alloy were examined.

Further, a CoFe alloy was formed by plating from a plating bath containing Co ions and Fe ions and further containing no saccharin sodium by an electroplating method using a pulse current, and the Fe ion concentration, the Co ion concentration, The ion concentration / Co ion concentration, the Fe composition ratio in the plated CoFe alloy, the Co composition ratio, and the soft magnetic properties and film properties of the CoFe alloy were examined.

In the plating bath, sodium chloride (5 g) was used.
/ L), boric acid (25 g / l) and sodium lauryl sulfate (0.02 g / l). As the film forming conditions, the plating bath temperature was set at 30 ° C., and the pH of the electrode was set at 2.35. The current density was set to 430 mA / cm ² . Furthermore, the duty ratio of pulse current (ON / OF
F) was set to 200/800 msec. In addition, a Co electrode was used for the electrode on the anode side.

Further, among CoFe alloys formed by plating saccharin sodium into the plating baths already described in Tables 1 to 6, some CoFe alloys were selected, and the soft magnetic properties and film properties of these CoFe alloys were determined. It was measured. In addition, a CoFe alloy was formed by plating from a plating bath having a new Fe ion concentration and a new Co ion concentration, not shown in Tables 1 to 6, and mixed with sodium saccharin, and the soft magnetic properties and film properties of these CoFe alloys were also measured. did. Table 7 shows the experimental results.

The "CoFe" column in Table 7 shows the experimental results of the CoFe alloy formed by plating from the plating bath containing saccharin sodium. The "CoFe-N" column shows the results from the plating bath containing no saccharin sodium. It is an experimental result of the CoFe alloy formed by plating.

[0195]

[Table 7]

Based on Table 7, the Fe of each CoFe alloy was
The relationship between the quantity and the soft magnetic properties and film properties is summarized below.
Also for NiFe alloys, the relationship between the amount of Fe contained in the NiFe alloy and the soft magnetic properties and film properties was examined.

FIG. 8 is a graph showing the relationship between the amount of Fe contained in the CoFe alloy or the NiFe alloy and the saturation magnetic flux density Bs.

As shown in FIG. 8, in the case of the NiFe alloy, the Fe content X is about 73% by mass at the maximum,
No more Fe can be contained in the plating film. The saturation magnetic flux density Bs is as high as about 1.9T,
A saturation magnetic flux density Bs of 2.0 T or more cannot be obtained.

On the other hand, in the case of a CoFe alloy, Fe can be contained in the plating film in an amount of 73% by mass or more. Here, as can be seen from FIG. 8, “CoFe” plated from a plating bath mixed with saccharin sodium was used.
It was found that “CoFe—N” formed by plating from a plating bath into which sodium saccharin was not mixed could increase the saturation magnetic flux density Bs.

8 and 9 (FIG. 9 is a graph showing the relationship between the Fe composition ratio of “CoFe—N” and the saturation magnetic flux density Bs in FIG. 8 in which the range of the vertical axis is particularly enlarged). As described above, a CoFe alloy (CoFe-) plated from a plating bath into which sodium saccharin is not mixed is used.
In the case of N), it was found that the saturation magnetic flux density Bs was 2.0 T or more when the Fe composition ratio was set to 50 mass% or more and 90 mass or less.

Further, a CoFe alloy (C) formed by plating from a plating bath into which saccharin sodium was not mixed was used.
oFe-N), when the Fe composition ratio is 60% by mass or more, 7
If it is set to 8% by mass or less, the saturation magnetic flux density Bs becomes 2.2
It turned out that 5T or more can be obtained.

Further, a CoFe alloy (C) plated from a plating bath containing no saccharin sodium was used.
oFe-N), when the Fe composition ratio is 65% by mass or more, 7
If it is set to 5% by mass or less, the saturation magnetic flux density Bs becomes 2.3
It was found that T or more could be obtained.

Therefore, the CoFe alloy formed by plating from a plating bath containing no saccharin sodium has an Fe composition ratio of 50% by mass or more and 90% by mass or less, preferably 60% by mass or more and 78% by mass or less. And more preferably 65% by mass or more and 75% by mass or less.

Next, a CoFe alloy formed by plating from a plating bath mixed with sodium saccharin (Co in FIG. 8)
Fe), the Fe content is increased from about 60% by mass or more to about 90% by mass.
It has been found that the saturation magnetic flux density Bs can be set to 2.0 T or more if the content is not more than the mass%. Thus, CoFe
It can be seen that the Bs can be higher in the alloy than in the NiFe alloy.

However, the F of the CoFe alloy formed by plating from the plating bath into which saccharin sodium was mixed.
When the e content is within the above range, there is a problem that in a part of the range, the crystal grain size is coarsened, and mainly the accompanying deterioration of the surface roughness is caused.

FIG. 10 is a graph showing the relationship between the Fe content in the CoFe alloy and the center line average roughness Ra of the film surface. As shown in FIG. 9, a CoFe alloy plated from a plating bath containing sodium saccharin (FIG. 9)
It can be seen that the center line average roughness Ra can be minimized when the Fe content of the graph (CoFe) is about 75% by mass.

As shown in FIG. 10, the Fe content was 68% by mass.
It can be seen that when the content is 80% by mass or less, the center line average roughness Ra of the film surface can be 9 nm or less.

When the Fe content is 68% by mass or more and 80% by mass or less, it can be seen from the graph of FIG. 8 that the saturation magnetic flux density Bs can be increased to 2.25T or more.

As described above, according to the present invention, CoFe plated from a plating bath mixed with sodium saccharin was used.
The Fe content of the alloy (the graph of CoFe in FIG. 8) was 68% by mass.
It can be seen that when the above is 80% by mass or less, the saturation magnetic flux density Bs can be made 2.0T or more, specifically 2.25T or more, and the center line average roughness Ra of the film surface can be made 9 nm or less.

As described in Tables 2 and 5 above, F
By setting the ratio of e ion concentration / Co ion concentration to 1.5 or more and 2.5 or less, the stirring effect is improved, so that
The amount of Fe contained in the Fe alloy can be set to be not less than 68% by mass and not more than 80% by mass, the crystal grain size can be suppressed from being coarsened, a dense film can be formed, and the saturation magnetic flux density can be reduced to 2.0T.
With the above, the center line average roughness can be reduced to 9 nm or less, and a CoFe alloy with less surface roughness can be manufactured.

On the other hand, in the case of a CoFe alloy plated from a plating bath containing no saccharin sodium,
As can be seen from the graph of “CoFe—N” in FIG. 10, even when the composition ratio of Fe is higher than 50% by mass and equal to or lower than 90% by mass, the center line average roughness Ra of the film surface can be easily suppressed to 9 nm or less. Depending on the composition ratio, the center line average roughness Ra is 5 nm.
The following can be suppressed.

The reason why the center line average roughness Ra of the film surface of the CoFe alloy plated from a plating bath containing no saccharin sodium is small is that the film does not contain the element S which lowers the corrosion resistance, and the crystal grain size is low. Effective miniaturization of the diameter is conceivable.

FIG. 11 is a graph showing the relationship between the Fe content of the CoFe alloy and the NiFe alloy and the coercive force Hc. As shown in FIG. 11, in the case of a CoFe alloy which is higher than the coercive force Hc of the NiFe alloy but is formed by plating from a plating bath composition in which sodium saccharin is not mixed (graph of “CoFe-N” shown in FIG. 11), F
By setting the composition ratio of e to 50% by mass or more and 90% by mass or less, it becomes possible to suppress the coercive force Hc to 2370 (A / m) or less. It is also found that the coercive force Hc can be reduced to 1580 (A / m) or less when the composition ratio of Fe is 70% by mass or more.

Further, as shown in FIG. 11, in the case of a CoFe alloy formed by plating from a plating bath composition containing sodium saccharin (graph “CoFe” shown in FIG. 11), the Fe composition ratio was 68% by mass or more. It is understood that the coercive force Hc can be reduced to 1580 (A / m) or less when the content is 80% by mass or less.

FIG. 12 is a graph showing the relationship between the Fe content of the CoFe alloy and the NiFe alloy and the specific resistance.
It is preferable that the specific resistance is large to some extent in order to suppress eddy current loss with a higher recording frequency in the future. Figure 1
As shown in FIG. 2, the CoFe alloy has a lower specific resistance than the NiFe alloy, but a CoFe alloy formed by plating from a plating bath in which sodium saccharin is not mixed in the plating bath ("CoFe-N" shown in FIG. 12). In the case of graph (1), the specific resistance can be increased to 17 (μΩ · cm) or more by setting the composition ratio of Fe to 50% by mass or more and 90% by mass or less.

In the case of a CoFe alloy formed by plating from a plating bath mixed with sodium saccharin (the graph of “CoFe” shown in FIG. 12), the Fe content is set to be 68% by mass or more and 80% by mass or less. The CoFe
25 (μΩ · cm) or more can be secured for the alloy.

Next, FIG. 13 is a graph showing the relationship between the Fe content of the CoFe alloy and the NiFe alloy and the film stress.
It is preferable that the film stress is small to some extent in order to suppress film peeling and cracking of the plating film. As shown in FIG. 13, in the case of CoFe plated from a plating bath mixed with sodium saccharin (graph of “CoFe—N” shown in FIG. 13), the composition ratio of Fe is 50% by mass or more and 90% by mass or less. By doing so, the film stress can be suppressed to 1200 (MPa) or less. When the Fe composition ratio is gradually increased, the film stress becomes smaller. When the Fe composition ratio becomes about 75% by mass or more, the film stress becomes 400 (MP).
a) It can be seen that it can be suppressed to the following.

Since saccharin sodium is a stress relieving agent, a CoFe alloy plated from a plating bath containing no saccharin sodium (“CoFe” in FIG. 13)
In the graph of “Fe—N”, the film stress tends to be larger than that of the CoFe alloy (graph of “CoFe” in FIG. 13) formed by plating from a plating bath mixed with sodium saccharin. However, the film stress was 1200 (MPa).
The CoFe can be used as a magnetic pole or a core material of the thin-film magnetic head if it can be suppressed below. Further, depending on the composition ratio of Fe, the film stress of the CoFe
Thus, CoFe can be more effectively used as the magnetic pole and core material of the thin-film magnetic head.

A CoFe alloy formed by plating from a plating bath mixed with sodium saccharin (“CoFe” in FIG. 13)
In the graph “Fe”), when the Fe content is in the range of 68% by mass or more and 80% by mass or less, although the film stress is larger than that of the NiFe alloy, the film stress is 400 MPa.
It is possible to suppress the following.

FIG. 14 is a graph showing the relationship between the Fe content of the CoFe alloy and the NiFe alloy and the anisotropic magnetic field Hk. As shown in FIG. 14, CoFe plated from a plating bath containing no saccharin sodium was used.
In the alloy ("CoFe-N" graph shown in FIG. 14),
It can be seen that when the composition ratio of Fe is set to 50% by mass or more and 90% by mass or less, an anisotropic magnetic field Hk comparable to or higher than that of the NiFe alloy can be obtained. In the case of a CoFe alloy formed by plating from a plating bath mixed with saccharin sodium (the graph of “CoFe” shown in FIG. 14), when the Fe composition ratio is 68% by mass or more and 80% by mass or less, the same as the NiFe alloy is obtained. It can be seen that an anisotropic magnetic field Hk can be obtained.

FIG. 15 is a graph showing the relationship between the Fe content of the CoFe alloy and the NiFe alloy and the crystal grain size. As shown in FIG. 15, a CoFe alloy formed by plating from a plating bath containing no saccharin sodium (graph of “CoFe—N” shown in FIG. 15)
When the composition ratio is 50% by mass or more and 90% by mass or less,
The crystal grain size can be made smaller than that of a CoFe alloy formed by plating from a plating bath mixed with sodium saccharin (the graph of “CoFe” shown in FIG. 15). Specifically, the crystal grain size can be suppressed to 250 ° or less. As described above, when the saccharin sodium is not mixed in the plating bath, a dense film can be formed as compared with the case where the saccharin sodium is mixed. This is because the center line average roughness of the film surface described in FIG. This is one of the reasons that Ra can be reduced.

In the case of a CoFe alloy formed by plating from a plating bath mixed with sodium saccharin (the graph of “CoFe” shown in FIG. 14), if the Fe composition ratio is 68% by mass or more and 80% by mass or less, the crystal grain size is reduced. 350 mm diameter
It can be reduced to the following.

FIG. 16 shows the Fe composition ratio when a CoFe alloy was formed by plating from a plating bath containing no saccharin sodium, the Fe ion concentration (g / l) and the Co ion concentration (g / l) in the plating bath. 4) and a graph showing the relationship between the ratio of Fe ion concentration / Co ion concentration.

As described above, in the present invention, the Fe composition ratio of the CoFe alloy formed by plating from the plating bath containing no saccharin sodium is set to be 50% by mass or more and 90% by mass or less. Considering the ratio of each Fe ion concentration / Co ion concentration in this graph and the “CoFe-N” column shown in Table 7, if the ratio of the Fe ion concentration / Co ion concentration is 1.0 or more and 17 or less, , Co
It is considered that the Fe composition ratio of the Fe alloy can be set to 50% by mass or more and 90% by mass or less. Therefore, in the present invention,
The ratio of the Fe ion concentration / Co ion concentration was set to 1.0 or more and 17 or less. At this time, the Co ion concentration is preferably approximately 0.2 g / l or more and 1.4 (g / l) or less, and the Fe ion concentration is approximately 1.0 g / l.
It is preferably at least g / l and at most 7.5 (g / l).

Next, a CoFe alloy plated from a plating bath containing no saccharin sodium was used.
A preferable Fe composition ratio is set to be not less than 60% by mass and not more than 78% by mass. “CoFe-N” shown in FIG. 16 and Table 7
Considering the ratio of each Fe ion concentration / Co ion concentration in the column, if the ratio of the Fe ion concentration / Co ion concentration is set to 1.0 g / l or more and 10 g / l or less, CoFe
It is considered that the Fe composition ratio of the alloy can be set at not less than 60% by mass and not more than 78% by mass. Therefore, in the present invention, the preferable range of the ratio of the Fe ion concentration / Co ion concentration is set to 1.0 g / l or more and 10 g / l or less. At this time, the Co ion concentration is preferably about 0.2 g / l or more and 1.4 (g / l) or less.
The ion concentration is approximately 1.0 g / l or more and 7.5 (g / g).
l) The following is preferred.

Next, the CoFe alloy formed by plating from a plating bath containing no saccharin sodium was used.
The preferred Fe composition ratio was set to 65% by mass or more and 75% by mass or less. “CoFe-N” shown in FIG. 16 and Table 7
Considering the ratio of each Fe ion concentration / Co ion concentration in the column, if the ratio of the Fe ion concentration / Co ion concentration is set to 3.0 or more and 8 or less, the Fe composition ratio of the CoFe alloy is 65% by mass or more. It is considered that it can be set to 75% by mass or less. Therefore, in the present invention, the preferable range of the ratio of the Fe ion concentration / Co ion concentration is set to 3.0 or more and 8 or less. At this time, the Co ion concentration is preferably about 0.2 g / l or more and 1.4 (g / l) or less, and the Fe ion concentration is about 1.0 g / l.
It is preferably 7.5 (g / l) or less.

[0227]

According to the present invention described in detail above, the saturation magnetic flux density Bs of 2.0 T or higher, which is higher than that of the NiFe alloy, can be stabilized by setting the Fe content of the CoFe alloy to 50 mass% to 90 mass%. Can be obtained. Further, by making the amount of Fe not less than 60% by mass and not more than 78% by mass, 2.2 is obtained.
A saturation magnetic flux density Bs of 5T or more can be obtained, and a saturation magnetic flux density of 2.3T or more can be obtained by setting the Fe content to 65% by mass or more and 75% by mass or less.

Further, in the present invention, when the content is within the above-mentioned composition range, a coarse film can be formed by suppressing the crystal grain size from being coarsened.
The center line average roughness Ra of the film surface can be set to 9 nm or less. Since the surface roughness can be suppressed as described above, a soft magnetic film having excellent corrosion resistance can be manufactured.

In the present invention, it is possible to optimize the Fe ion concentration in the plating bath with respect to the Co ion concentration and to obtain the above-described Fe composition ratio and saturation magnetic flux density by pulse plating without mixing saccharin sodium in the plating bath. Will be possible.

In the present invention, the above-mentioned CoFe alloy can be used, for example, as a core material of a thin-film magnetic head. This makes it possible to manufacture a thin-film magnetic head which is excellent in high recording density and excellent in corrosion resistance.

[Brief description of the drawings]

FIG. 1 is a partial front view of a thin-film magnetic head according to a first embodiment of the present invention;

2 is a longitudinal sectional view of FIG. 1,

FIG. 3 is a partial front view of a thin-film magnetic head according to a second embodiment of the present invention;

FIG. 4 is a longitudinal sectional view of FIG. 3;

FIG. 5 is a longitudinal sectional view of a thin-film magnetic head according to a third embodiment of the present invention,

FIG. 6 is a longitudinal sectional view of a thin-film magnetic head according to a fourth embodiment of the present invention,

FIG. 7 is a longitudinal sectional view of a thin-film magnetic head according to a fifth embodiment of the present invention;

FIG. 8 shows a CoFe alloy (CoFe—N) plated from a plating bath containing no saccharin sodium using electroplating using a pulse current and a CoFe plated from a plating bath mixed with saccharin sodium. Alloy (CoFe) and NiFe alloy F
a graph showing the relationship between the amount of e and the saturation magnetic flux density,

FIG. 9 shows a CoFe alloy (C) formed by plating from a plating bath not containing saccharin sodium shown in FIG. 8;
oFe-N) is a graph showing the relationship between the Fe amount and the saturation magnetic flux density.

FIG. 10 shows a CoFe alloy (CoFe—N) plated from a plating bath containing no saccharin sodium using electroplating using a pulse current and CoFe plated from a plating bath mixed with sodium saccharin. A graph showing the relationship between the Fe content of the alloy (CoFe) and the NiFe alloy and the center line average roughness Ra of the film surface;

FIG. 11 shows a CoFe alloy (CoFe—N) formed by plating from a plating bath containing no saccharin sodium using electroplating using a pulse current, and a CoFe alloy formed by plating from a plating bath mixed with sodium saccharin. A graph showing the relationship between the Fe content of the alloy (CoFe) and the NiFe alloy and the coercive force Hc;

FIG. 12 shows a CoFe alloy (CoFe—N) plated from a plating bath containing no saccharin sodium using electroplating using a pulse current and a CoFe plated from a plating bath mixed with sodium saccharin. A graph showing the relationship between the Fe content and the specific resistance of the alloy (CoFe) and the NiFe alloy,

FIG. 13 shows a CoFe alloy (CoFe-N) formed by plating from a plating bath containing no saccharin sodium using electroplating using a pulse current, and a CoFe alloy formed by plating from a plating bath mixed with sodium saccharin. A graph showing the relationship between the Fe content of the alloy (CoFe) and the NiFe alloy and the film stress;

FIG. 14 shows a CoFe alloy (CoFe—N) plated from a plating bath containing no saccharin sodium using electroplating using a pulse current and a CoFe alloy plated from a plating bath containing saccharin sodium. A graph showing the relationship between the Fe content of the alloy (CoFe) and the NiFe alloy and the anisotropic magnetic field Hk;

FIG. 15 shows a CoFe alloy (CoFe—N) plated from a plating bath containing no saccharin sodium using electroplating using a pulse current and a CoFe plated from a plating bath mixed with saccharin sodium. A graph showing the relationship between the Fe content and the crystal grain size of the alloy (CoFe) and the NiFe alloy,

FIG. 16 shows the amount of Fe in a CoFe alloy plated from a plating bath in which electroplating using a pulse current was used and in which saccharin sodium was not mixed, and the ratio of Fe ion concentration / Co ion concentration in the plating bath and Fe ions. A graph showing a relationship between the concentration (g / l) and the Co ion concentration (g / l);

[Description of Signs] 11 Slider 10 Magnetoresistive element 16 Lower core layer (upper shield layer) 18, 30 Magnetic pole portion 19, 32, 50 Lower magnetic pole layer 20, 33 Gap layer 21, 34 Upper magnetic pole layer 22, 40, 46 55 upper core layer 41 magnetic gap layer 47 high Bs layer 48 upper layer

Claims (28)

[Claims] 1. The composition formula is represented by Co _1-x Fe _X , and the composition ratio X of Fe is not less than 50% by mass and not more than 90% by mass;
A soft magnetic film characterized by being formed by plating. 2. The soft magnetic film according to claim 1, wherein the composition ratio of Fe is not less than 60% by mass and not more than 78% by mass. 3. The soft magnetic film according to claim 1, wherein the composition ratio of Fe is 65% by mass or more and 75% by mass or less. 4. The soft magnetic film has a saturation magnetic flux density Bs of 2.
4. The soft magnetic film according to claim 1, which has a temperature of 0 T or more. 5. The soft magnetic film according to claim 2, wherein the saturation magnetic flux density Bs is 2.25 T or more. 6. The soft magnetic film according to claim 3, wherein said saturation magnetic flux density Bs is 2.30 T or more. 7. A center line average roughness R of a surface of the soft magnetic film.
7. The soft magnetic film according to claim 1, wherein a is 9 nm or less. 8. A center line average roughness R of a surface of the soft magnetic film.
The soft magnetic film according to claim 7, wherein a is 5 nm or less. 9. The composition formula is represented by Co _1-x Fe _X , and the composition ratio X of Fe is 68% by mass or more and 80% by mass or less,
A soft magnetic film characterized by being formed by plating. 10. The soft magnetic film according to claim 9, wherein the soft magnetic film has a saturation magnetic flux density Bs of 2.0 T or more. 11. The soft magnetic film according to claim 10, wherein said saturation magnetic flux density Bs is 2.25 T or more. 12. The soft magnetic film according to claim 9, wherein a center line average roughness Ra of the film surface of the soft magnetic film is 9 nm or less. 13. A thin-film magnetic head comprising: a lower core layer made of a magnetic material; an upper core layer formed on the lower core layer via a magnetic gap; and a coil layer for applying a recording magnetic field to both core layers. A thin-film magnetic head, wherein at least one of the core layers is formed of the soft magnetic film according to any one of claims 1 to 12. 14. The thin-film magnetic head according to claim 13, wherein a lower magnetic pole layer is formed on the lower core layer at a surface facing the recording medium, and the lower magnetic pole layer is formed of the soft magnetic film. 15. A lower core layer and an upper core layer, and a width dimension between the lower core layer and the upper core layer in the track width direction is regulated to be shorter than the lower core layer and the upper core layer. A magnetic pole portion, wherein the magnetic pole portion includes a lower magnetic pole layer continuous with the lower core layer, an upper magnetic pole layer continuous with the upper core layer, and a gap layer located between the lower magnetic pole layer and the upper magnetic pole layer. And
Alternatively, the magnetic pole portion includes an upper magnetic pole layer continuous with an upper core layer, and a gap layer located between the upper magnetic pole layer and the lower core layer. The upper magnetic pole layer and / or the lower magnetic pole layer includes: A thin-film magnetic head formed of the soft magnetic film according to claim 1. 16. The core layer, wherein at least a portion adjacent to the magnetic gap is formed of two or more magnetic layers, or the pole layer is formed of two or more magnetic layers. The thin-film magnetic head according to any one of claims 13 to 15, wherein the magnetic layer in contact is formed by the soft magnetic film. 17. The magnetic layer other than the magnetic layer in contact with the magnetic gap is formed of a CoFe alloy, and the composition ratio of Fe in the other magnetic layer is determined by adjusting the Fe composition ratio of the magnetic layer on the side in contact with the magnetic gap layer. 17. The thin-film magnetic head according to claim 16, wherein the composition ratio X is smaller than X. 18. The ratio of Fe ion concentration / Co ion concentration in a plating bath containing no saccharin sodium to 1.0 or more and 17.0 or less, and the Fe composition ratio X is determined by an electroplating method using a pulse current. A method for producing a soft magnetic film, comprising plating a Co _1-x Fe _x film having a content of 50% by mass or more and 90% by mass or less. 19. The ratio of Fe ion concentration / Co ion concentration in a plating bath into which sodium saccharin is not mixed is set to 1.0 or more and 10.0 or less, and the Fe composition ratio X is determined by an electroplating method using a pulse current. A method for producing a soft magnetic film, comprising plating a Co _1-x Fe _{x material} having a content of 60% by mass or more and 78% by mass or less. 20. The ratio of Fe ion concentration / Co ion concentration in a plating bath into which sodium saccharin is not mixed is adjusted to 3.0 or more and 8.0 or less, and the Fe composition ratio X is determined by an electroplating method using a pulse current. 7 at 65% by mass or more
A method for producing a soft magnetic film, comprising forming a plating of Co _1-x Fe _x of 5 mass% or less. 21. The ratio of Fe ion concentration / Co ion concentration in a plating bath mixed with saccharin sodium is set to 1.
A soft coating characterized by forming a Co _1-x Fe _X having a Fe composition ratio X of 68% by mass or more and 80% by mass or less by an electroplating method using a pulse current with a value of 5 or more and 2.5 or less. Manufacturing method of magnetic film. 22. In the plating bath, 2-butyne-1,
21. The method for producing a soft magnetic film according to claim 18, wherein 4-diol is mixed. 23. The method for producing a soft magnetic film according to claim 18, wherein sodium 2-ethylhexyl sulfate is mixed into the plating bath. 24. A lower core layer made of a magnetic material, an upper core layer facing the lower core layer via a magnetic gap on a surface facing the recording medium, and a coil layer for inducing a recording magnetic field in both core layers. A method for manufacturing a thin-film magnetic head comprising: forming at least one core layer by plating with a soft magnetic film according to the manufacturing method according to any one of claims 18 to 23. . 25. The method of manufacturing a thin-film magnetic head according to claim 24, wherein a lower magnetic pole layer is protruded on the lower core layer at a surface facing a recording medium, and the lower magnetic pole layer is formed by plating with the soft magnetic film. . 26. A lower core layer and an upper core layer, and a width dimension between the lower core layer and the upper core layer in a track width direction is regulated to be shorter than the lower core layer and the upper core layer. A magnetic pole portion, wherein the magnetic pole portion is formed of a lower magnetic pole layer continuous with the lower core layer, an upper magnetic pole layer continuous with the upper core layer, and a gap layer located between the lower magnetic pole layer and the upper magnetic pole layer. Alternatively, the magnetic pole portion is formed of an upper magnetic pole layer continuous with an upper core layer, and a gap layer located between the upper magnetic pole layer and the lower core layer. A method for manufacturing a thin-film magnetic head, comprising: forming a magnetic pole layer by plating with a soft magnetic film according to the manufacturing method according to claim 18. 27. The core layer is formed of two or more magnetic layers at least at a portion adjacent to a magnetic gap, or the magnetic pole layer is formed of two or more magnetic layers. 27. The magnetic layer in contact with the magnetic gap is formed by plating with the soft magnetic film.
The method for manufacturing a thin-film magnetic head according to any one of the above. 28. A magnetic layer other than the magnetic layer in contact with the magnetic gap is formed of a CoFe alloy, and the composition ratio of Fe of the other magnetic layer at this time is determined by the magnetic layer on the side in contact with the magnetic gap layer. 28. The method of manufacturing a thin film magnetic head according to claim 27, wherein the composition ratio of Fe is smaller than X.