JP3694471B2 - Thin film magnetic head and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a piggyback type thin film magnetic head comprising a recording head and a reproducing head formed on the recording head via an insulating layer, and in particular, to increase the recording density. The present invention also relates to a thin film magnetic head capable of suppressing magnetic interference between the recording head and the reproducing head and improving corrosion resistance, and a method of manufacturing the same.
[0002]
[Prior art]
FIG. 17 is a partial longitudinal sectional view of the structure of a conventional thin film magnetic head. Here, the longitudinal section means a section obtained by cutting the thin film magnetic head in the height direction (Y direction in the drawing) and parallel to the film thickness direction. The meaning of the longitudinal section is the same below.
[0003]
Reference numeral 1 shown in FIG. 17 denotes alumina-titanium carbide (Al₂O_Three-TiC), and on this slider 1, Al₂O_ThreeA thin film magnetic head 3 is formed through the film 2.
[0004]
The thin-film magnetic head 3 shown in FIG. 17 has a structure in which a reproducing MR head h1 and a recording inductive head h2 are laminated. The MR head h2 has a lower shield layer 4 made of a magnetic material such as a giant magnetoresistive element. The magnetoresistive effect element 5 utilizing the effect (GMR effect), the gap layer 6 made of an insulating material formed on the lower shield layer 4 and above and below the magnetoresistive effect element 5, and the gap layer 6 are formed. The upper shield layer 7 is made of a magnetic material.
[0005]
In the thin film magnetic head 3 of the type shown in FIG. 17, the upper shield layer 7 also functions as a lower core layer of the inductive head h2. That is, the upper shield layer 7 has both a function as a shield of the MR head h1 and a function as a core of the inductive head h2.
[0006]
The inductive head h2 includes a lower core layer 7, Al₂O_ThreeThe magnetic gap layer 8, the coil layer 9, the insulating layer 10 formed above and below the coil layer 9, and the upper core layer 11 are formed.
[0007]
As shown in FIG. 17, the front end portion 11a of the upper core layer 11 is opposed to the front end surface of the thin film magnetic head 3 (the surface facing the recording medium D) on the lower core layer 7 with the magnetic gap layer 8 interposed therebetween. The base end portion 11b of the upper core layer 11 is magnetically connected to the surface of the lower core layer 7 at the rear in the height direction (Y direction in the drawing).
[0008]
On the upper core layer 11 is Al.₂O_ThreeIt is covered with the protective layer 12 formed by the above.
[0009]
As shown in FIG. 17, a protective layer 13 made of, for example, DLC (diamond-like carbon) having a predetermined thickness is formed on the front end surface (the surface facing the recording medium D) of the thin-film magnetic head 3. Is formed.
[0010]
However, the structure of the thin film magnetic head shown in FIG. That is, in the thin film magnetic head shown in FIG. 17, since the upper shield layer 7 functioning as a shield of the MR head h1 also functions as a lower core layer of the inductive head h2, for example, the magnetic action of the lower core layer 7 during recording is Even when switched to playback, it remains a little, resulting in a reduction in the function of the upper shield during playback of the lower core layer 7, and the problem of magnetic interference particularly during switching between recording and playback is the problem. It became more and more noticeable as the recording density increased.
[0011]
Therefore, the structure of the thin film magnetic head shown in FIG. 17 is improved as shown in FIG. In FIG. 18, the same reference numerals as those in FIG. 17 indicate the same layers as in FIG. In FIG. 18, the upper shield layer 14 and the lower core layer 15 are separately formed. Between the upper shield layer 14 and the lower core layer 15, for example, Al₂O_ThreeAn insulating layer 16 such as is interposed.
[0012]
As shown in FIG. 18, the thin film magnetic head in which the MR head h1 and the inductive head h2 are completely separated without using the same layer is called a piggy back type thin film magnetic head. .
[0013]
With a piggyback thin film magnetic head, magnetic interference between the MR head h1 and the inductive head h2 can be suppressed even when the recording density is increased, and both the recording and reproducing characteristics can be improved appropriately. it was thought.
[0014]
[Problems to be solved by the invention]
However, when the lower core layer 15 and the upper shield layer 14 are separated as in the thin film magnetic head having the structure shown in FIG. 18, the lower core layer 15 and the upper shield layer 14 are easily corroded. . This problem becomes more pronounced as the recording density increases.
[0015]
In order to achieve higher recording density more effectively, it is necessary to reduce the spacing loss. In order to reduce the spacing loss, the flying distance H1 from the front end surface (surface facing the recording medium D) of the thin film magnetic head 3 shown in FIG. 18 to the surface of the recording medium D may be shortened.
[0016]
In order to shorten the flying distance H1, the flying height when the thin film magnetic head 3 floats on the recording medium D is reduced, and the film of the protective layer 13 formed on the front end surface of the thin film magnetic head 3 is reduced. It is necessary to reduce the thickness T1.
[0017]
However, when the thickness T1 of the protective layer 13 is reduced, defects such as pinholes are formed in the protective layer 13, and for example, the solvent used in the process of manufacturing the magnetic head 3 and the moisture in the air It penetrates into the protective layer 13 and easily reaches the lower core layer 15 and the upper shield layer 14. At this time, since a potential difference is generated between the lower core layer 15 and the upper shield layer 14, both the lower core layer 15 and the upper shield layer 14 are caused by a battery effect due to the potential difference between the lower core layer 15 and the upper shield layer 14. There was a problem that either one of them was corroded.
[0018]
In the case of the piggyback type as shown in FIG. 18, since the lower core layer 15 and the upper shield layer 14 are formed separately, the lower core layer 15 and the upper shield layer 14 are formed of different magnetic materials. In this case, since the potential difference between the lower core layer 15 and the upper shield layer 14 is further increased, the layer on the side having a high ionization tendency corrodes violently due to the battery effect, and the recording characteristics and the reproduction characteristics are large. It tends to decline.
[0019]
Further, solving the above-mentioned corrosion problem is important for achieving a high recording density, but at the same time improving the corrosion resistance and at the same time the advantage of the piggyback type, that is, the MR head h1 and the inductive head. The effect of appropriately reducing the magnetic interference between h2 must not be lowered.
[0020]
Accordingly, the present invention is to solve the above-described conventional problems, and in particular, while maintaining the effect of reducing magnetic interference between the inductive head and the MR head, the conductive layer is provided between the lower core layer and the upper shield layer. A thin-film magnetic head and a method of manufacturing the same, which can be electrically connected to each other so that the lower core layer and the upper shield layer have the same potential, and the corrosion resistance of the lower core layer and the upper shield layer can be appropriately improved. It is intended to provide.
[0021]
[Means for Solving the Problems]
  The present invention relates to a reproducing head having a lower shield layer, a magnetoresistive effect element, and an upper shield layer, a lower core layer facing the upper shield layer via an insulating layer, a magnetic gap layer, an upper portion In a thin film magnetic head comprising a core layer and a recording head having a coil layer formed between the lower core layer and the upper core layer,
  A portion between the upper shield layer and the lower core layer isFormed of magnetic materialConductive connection with conductive layerThe base end portion of the upper core layer is magnetically connected to the lower core layer on the rear side in the height direction, and the front end surface of the conductive layer is formed on the rear side in the height direction with respect to the front end surface of the base end portion. BeenIt is characterized by being.
[0022]
When a part of the upper shield layer and the lower core layer are electrically connected by a conductive layer as in the present invention, the upper shield layer and the lower core layer have the same potential, so that the front end surface of the thin film magnetic head (opposite the recording medium) Even if the protective layer formed on the surface to be thinned is thinned to reduce the spacing loss, the battery effect caused by the permeation of moisture in the solvent or air is reduced compared to the conventional case, and the upper shield layer is reduced. And the corrosion resistance of the lower core layer can be improved.
[0023]
Further, even if the upper shield layer and the lower core layer are electrically connected by a conductive layer as in the present invention, the conductive layer is provided only in a part between the upper shield layer and the lower core layer. Magnetic interference between the lower core layer and the upper shield layer at the time of reproduction and reproduction can be reduced as compared with the conventional case (conventional example in FIG. 17) in which the lower core layer and the upper shield layer are combined in the same layer. It is possible to maintain the superiority as a piggyback type.
[0024]
  In the present invention, the conductive layer is formed of a magnetic material.CageThe conductive layer is preferably formed of the same material as the lower core layer. Thereby, the manufacturing process of the said conductive layer can be simplified.
[0026]
  In the present invention, the base end portion of the upper core layer is magnetically connected to the lower core layer at the rear in the height direction, and the front end surface of the conductive layer is in the height direction than the front end surface of the base end portion. Formed backwardsing.
[0027]
  Alternatively, in the present invention, the upper core layer and the lower core layer are magnetically connected via a back gap layer at the rear in the height direction, and the front end surface of the conductive layer is higher than the front end surface of the back gap layer. Formed in the rear directionHaveThe
[0028]
As described above, when the front end surface of the conductive layer is formed on the height side of the front end surface of the base end portion of the upper core layer or the front end surface of the back gap layer, the conductive layer is made of a magnetic material. However, the recording magnetic field passing through the lower core layer and the upper core layer has little or no influence on the upper shield layer through the conductive layer. Magnetic interference between the core layer and the upper shield layer can be suppressed.
[0029]
In the present invention, the cross-sectional area in the direction parallel to the film surface of the conductive layer is 1 μm.²Above 500μm²It is preferably formed as follows. Thereby, the magnetic interference between the lower core layer and the upper shield layer at the time of recording and reproduction can be more appropriately suppressed.
[0030]
In the present invention, the lower core layer and the upper shield layer are preferably formed of different magnetic materials. The magnetic characteristic required for the lower core layer is particularly a high saturation magnetic flux density Bs. On the other hand, the magnetic characteristics required for the upper shield layer are particularly high permeability and low magnetostriction constant, and the saturation magnetic flux density Bs does not need to be as high as that of the lower core layer. Since the magnetic properties required for the lower core layer and the upper shield layer are different from each other, the lower core layer and the upper shield layer are formed of different magnetic materials, respectively, and the core function and the upper shield layer of the lower core layer are formed. It is preferable to improve the shielding function.
[0031]
In the present invention, a protective layer is preferably formed on the front end surface of the thin film magnetic head, and the thickness of the protective layer is preferably 0.5 nm or more and 5 nm or less. As a result, a spacing loss can be appropriately reduced, and a thin film magnetic head that can cope with a higher recording density can be manufactured. In the present invention, the protective layer is preferably formed of one or more of DLC (diamond-like carbon) and ta-C (Tetrahedral Amorphous Carbon).
[0032]
  The present invention relates to a method of manufacturing a thin film magnetic head,
(A) forming a read head having a lower shield layer, a magnetoresistive element, and an upper shield layer;
(B) Part of the upper shield layerMade of magnetic materialForming a conductive layer and forming an insulating layer around the conductive layer;
(C) forming a lower core layer from above the insulating layer to the conductive layer;
(D) forming a coil layer and an upper core layer on the lower core layer, and forming a recording head having the lower core layer, the coil layer, and the upper core layer;
  The front end surface of the base end portion of the upper core layer that is magnetically connected to the lower core layer in the step (d), or the base end portions of the lower core layer and the upper core layer in the step (d). The front end surface of the back gap layer formed therebetween is formed so as to be positioned closer to the recording medium than the front end surface of the conductive layer.
[0033]
  According to the method of manufacturing a thin film magnetic head in the present invention, a conductive layer can be formed appropriately and easily in part between the lower core layer and the upper shield layer, and the lower core layer and the upper shield layer are conductively connected. Since the lower core layer and the upper shield layer can be at the same potential, a thin film magnetic head having excellent corrosion resistance can be manufactured.
In the present invention, the front end surface of the base end portion of the upper core layer that is magnetically connected to the lower core layer is formed in the step (d), or the lower core layer and the upper core are formed in the step (d). The front end surface of the back gap layer formed between the base end portions of the layers is formed so as to be positioned closer to the recording medium than the front end surface of the conductive layer. This makes it possible to manufacture a thin film magnetic head that can more appropriately suppress magnetic interference between the lower core layer and the upper shield layer during recording and reproduction.
[0034]
Moreover, in this invention, it is preferable to have the following processes instead of the said (b) process and (c) process.
(E) forming an insulating layer on the upper shield layer, forming a hole portion penetrating to the upper shield layer in the insulating layer, and forming a plating base layer from the hole portion to the insulating layer; ,
(F) A step of plating a lower core layer on the plating base layer and forming a conductive layer integrated with the lower core layer in the hole.
[0035]
Thereby, the lower core layer and the conductive layer can be formed simultaneously in the same process. Therefore, it is preferable because the production of the conductive layer can be facilitated.
[0037]
In the present invention, it is preferable that the lower core layer is formed of a magnetic material different from that of the upper shield layer in the steps (c) and (f).
[0038]
Since the thin film magnetic head of the present invention is a piggyback type, the lower core layer and the upper shield layer can be formed of different magnetic materials. At this time, it is preferable to select a material having magnetic characteristics necessary for improving the core function of the lower core layer and magnetic characteristics necessary for improving the shield function of the upper shield layer.
[0039]
In the present invention, after the step (d), a protective layer is formed on the surface facing the recording medium, and at this time, the protective layer is preferably formed with a thickness of 0.5 nm to 5 nm. . As a result, it is possible to reduce the spacing loss and manufacture a thin film magnetic head that can appropriately cope with an increase in recording density.
[0040]
In the present invention, the protective layer is preferably formed of one or more of DLC (diamond-like carbon) and ta-C (Tetrahedral Amorphous Carbon).
[0041]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a partial longitudinal sectional view of a thin film magnetic head according to a first embodiment of the present invention. In the following, the X direction shown in FIG. 1 is called the track width direction, and the Y direction shown is called the height direction. The Z direction shown in the figure is the moving direction of the recording medium D.
[0042]
The thin film magnetic head shown in FIG. 1 is a type of thin film called a piggy back type in which the reproducing MR head h1 and the recording inductive head h2 are separately formed without having a dual layer. It is a magnetic head.
[0043]
Reference numeral 20 shown in FIG. 1 denotes alumina-titanium carbide (Al₂O_Three-TiC) or the like. The thin film magnetic head 21 in the present invention has an Al on the slider 20.₂O_ThreeAnd SiO₂And the like through the insulating layer 22.
[0044]
As shown in FIG. 1, a lower shield layer 23 made of a magnetic material such as permalloy (NiFe alloy) or sendust (Fe—Al—Si alloy) is formed on the insulating layer 22.
[0045]
A magnetoresistive element 25 is formed on the lower shield layer 23 via a gap layer 24. The front end surface of the magnetoresistive effect element 25 is formed on the same plane as the front end surface of the thin film magnetic head 21 (the surface facing the recording medium D) as shown in FIG. The magnetoresistive effect element 25 is, for example, a giant magnetoresistive effect element represented by a spin valve thin film element utilizing a giant magnetoresistive effect (GMR effect), or a tunnel magnetoresistive effect type utilizing a tunnel effect (TMR effect). An element is an anisotropic magnetoresistive element utilizing an anisotropic magnetic effect (AMR effect).
[0046]
As shown in FIG. 1, the gap layer 24 is also formed on the magnetoresistive effect element 25, and the upper and lower sides (Z direction in the drawing) of the magnetoresistive effect element 25 are surrounded by the gap layer 24. Normally, the gap layer 24 formed on the lower side of the magnetoresistive effect element 25 is called a lower gap layer, and the gap layer 24 formed on the upper side of the magnetoresistive effect element 25 is called an upper gap layer. The lower gap layer and the upper gap layer are simplified in the drawing and are shown as one gap layer 24.
[0047]
As shown in FIG. 1, an upper shield layer 26 made of a magnetic material such as permalloy is formed on the gap layer 24.
[0048]
As shown in FIG. 1, the front end surfaces of the lower shield layer 23 and the upper shield layer 26 are the front end surface of the thin film magnetic head 21 (the surface facing the recording medium D) together with the front end surface of the magnetoresistive effect element 25. It is formed on the same plane.
[0049]
From the lower shield layer 23 to the upper shield layer 26 shown in FIG. 1 is a reproducing head, that is, an MR head h1.
[0050]
As shown in FIG. 1, Al is formed on the upper shield layer 26.₂O_ThreeAnd SiO₂An insulating layer (separation layer) 27 made of an insulating material such as is formed.
[0051]
As shown in FIG. 1, a lower core layer 28 made of a magnetic material such as a NiFe alloy (permalloy) is formed on the insulating layer 27.
[0052]
A Gd determining layer 29 made of, for example, an organic material is formed on the lower core layer 28 at a position away from the front end face of the thin film magnetic head 21 in the height direction (Y direction in the drawing). A back gap layer 30 made of a magnetic material is formed behind the Gd determining layer 29 in the height direction (Y direction in the drawing). The back gap layer 30 is magnetically connected to the lower core layer 28.
[0053]
As shown in FIG. 1, from the bottom to the front end surface (the surface facing the recording medium D) of the thin film magnetic head 21 from above the Gd determining layer 29, the bottom pole layer 31, the magnetic gap layer 32, and the top pole layer 33 A magnetic pole layer 34 is formed. The lower magnetic pole layer 31 and the upper magnetic pole layer 33 are formed of a magnetic material such as a NiFe alloy, a CoFe alloy, or a CoFeNi alloy. Meanwhile, the magnetic gap layer 32 is formed of a nonmagnetic conductive material such as NiP that can be plated.
[0054]
As shown in FIG. 1, between the pole layer 34 and the back gap layer 30 and on the lower core layer 28, Al₂O_ThreeA first coil layer 36 made of a nonmagnetic conductive material such as Cu is wound around an insulating base layer 35 such as.
[0055]
The conductor portions of the first coil layer 36 are filled with an organic insulating material layer 37 such as a resist, and the first coil layer 36 and the organic insulating material layer 37 are made of Al.₂O_ThreeIt is covered with an inorganic insulating material layer 38 or the like. The surfaces of the inorganic insulating material layer 38, the pole layer 34, and the back gap layer 30 are planarized by using a CMP technique or the like.
[0056]
As shown in FIG. 1, a second coil layer 39 is wound on the inorganic insulating material layer 38. As shown in FIG. 1, the second coil layer 39 is covered with an organic insulating material layer 40 such as a resist, and an upper core made of a magnetic material such as a NiFe alloy is further formed on the organic insulating material layer 40. The layer 41 is formed by frame plating, for example. As shown in FIG. 1, the tip 41 a of the upper core layer 41 is magnetically connected to the upper magnetic pole layer 33. In this embodiment, the front end surface of the tip portion 41a is not formed on the same plane as the front end surface (the surface facing the recording medium D) of the thin film magnetic head 21, but recedes in the height direction (Y direction in the drawing). However, the front end surface of the tip portion 41 a may be formed on the same plane as the front end surface of the thin film magnetic head 21.
[0057]
The base end portion 41 b of the upper core layer 41 is magnetically connected to the back gap layer 30.
[0058]
A recording head, i.e., an inductive head h <b> 2 is configured by each layer from the lower core layer 28 to the upper core layer 41 shown in FIG. 1.
[0059]
In the inductive head h2, when a recording current flows through the first coil layer 36 and the second coil layer 39, a recording magnetic field is generated, and the upper magnetic pole layer 33-the upper core layer 41-the back gap layer 30-the lower core layer 28-the lower part. A magnetic path passing through the pole layer 31 is formed. A signal is recorded on the recording medium D by a leakage magnetic field from between the lower magnetic pole layer 31 and the upper magnetic pole layer 33 sandwiching the magnetic gap layer 32.
[0060]
As shown in FIG. 1, the upper core layer 41 is made of Al.₂O_ThreeThe protective layer 42 is covered. As shown in FIG. 1, a protective layer 44 is formed on the front end surface (the surface facing the recording medium D) of the thin film magnetic head 21. The protective layer 44 is preferably formed of one or more of DLC (diamond-like carbon) and ta-C (Tetrahedral Amorphous Carbon).
[0061]
The characteristic part of the thin film magnetic head in the present invention will be described below. A part between the upper shield layer 26 and the lower core layer 28 is conductively connected by a conductive layer 43. When the upper shield layer 26 and the lower core layer 28 are conductively connected by the conductive layer 43, the upper shield layer 26 and the lower core layer 28 can have the same potential.
[0062]
Therefore, when the thin film magnetic head is immersed in a solvent during the manufacturing process of the thin film magnetic head 21, the solvent penetrates from the protective film 43 formed on the front end surface of the thin film magnetic head 21, and During driving, moisture in the air permeates from the protective film 43 formed on the front end surface of the thin film magnetic head 21, and the solvent and moisture reach the upper shield layer 26 and the lower core layer 28. However, an electrical effect is hardly generated or does not occur between the upper shield layer 26 and the lower core layer 28, and corrosion of the upper shield layer 26 and the lower core layer 28 can be appropriately suppressed as compared with the conventional case. .
[0063]
Further, even if the upper shield layer 26 and the lower core layer 28 are electrically connected by the conductive layer 43 as in the present invention, the conductive layer 43 is provided only in a part between the upper shield layer 26 and the lower core layer 28. Therefore, the magnetic interference between the lower core layer 28 and the upper shield layer 26 is the same as that of the prior art in which the lower core layer 28 and the upper shield layer 26 are formed of the same layer (conventional in FIG. 17). Compared to example), it is possible to keep the superiority as a piggyback type appropriately. Further, when the conductive layer 43 is formed of a nonmagnetic conductive material, magnetic interference between the lower core layer 28 and the upper shield layer 26 is caused by the conventional structure in which the conductive layer 43 is not formed (the conventional structure in FIG. 18). It can be mitigated in the same way as in Example), and it becomes possible to maintain the superiority as a piggyback type more appropriately.
[0064]
In the present invention, the thickness of the protective layer 44 formed on the front end face of the thin film magnetic head 21 is preferably 0.5 nm or more and 5 nm or less. As a result, the flying distance H2 between the front end face of the thin film magnetic head 21 and the recording medium D can be shortened, and the spacing loss can be reduced. In the present invention, since the protective layer 44 is formed in such a thin film, defects such as pinholes are formed in the protective layer 44, and the solvent or air used in the manufacturing process of the thin film magnetic head 21 is formed. Even if the moisture therein is more easily penetrated into the lower core layer 28 and the upper shield layer 26, in the present invention, as described above, the lower core layer 28 and the upper shield layer 26 are set to the same potential. A battery effect is unlikely to occur between the lower core layer 28 and the upper shield layer 26, and the lower core layer 28 and the upper shield layer 26 are less likely to be corroded than in the prior art, and a thin film magnetic head having excellent reproduction characteristics and recording characteristics. Can be manufactured.
[0065]
Next, the material of the conductive layer 43 will be described below. The conductive layer 43 may be formed of a magnetic material. In the present invention, even if the conductive layer 43 is formed of a magnetic material, the conductive layer 43 is formed only in a part between the lower core layer 28 and the upper shield layer 26. Compared with the case where the core layer 28 and the upper shield layer 26 are formed of the same layer, magnetic interference between the lower core layer 28 and the upper shield layer 26 can be appropriately suppressed during recording and reproduction. It is possible to maintain the superiority as a piggyback type.
[0066]
In particular, when the conductive layer 43 is formed of a magnetic material, the conductive layer 43 can be formed of the same material as the lower core layer 28, and the formation of the conductive layer 43 can be facilitated.
[0067]
FIG. 2 is a partially enlarged longitudinal sectional view showing a state in which the lower core layer 28 and the conductive layer 43 are formed of the same material and integrated.
[0068]
As shown in FIG. 2, an insulating layer 27 is formed on the upper shield layer 26, and a hole 27 a penetrating to the upper surface of the upper shield layer 26 is formed in the insulating layer 43. A plating base layer 45 is formed from the insulating layer 27 to the upper shield layer 26 exposed from the hole 27a. The plating base layer 45 is a NiFe alloy or the like, and is formed by sputtering, for example. Then, the lower core layer 28 is formed on the plating base layer 45 by electroplating. At this time, a plating layer is also formed in the hole portion 27a formed in the insulating layer 27, and this plating layer functions as a conductive layer 43 that electrically connects the lower core layer 28 and the upper shield layer 26.
[0069]
Alternatively, in the present invention, the conductive layer 43 may be formed separately from the lower core layer 28. This state is shown in the partially enlarged sectional view of FIG.
[0070]
A conductive layer 43 is formed on the upper shield layer 26 shown in FIG. The conductive layer 43 may be formed of a magnetic material or a nonmagnetic conductive material.
[0071]
As shown in FIG. 3, the periphery of the conductive layer 43 is covered with the insulating layer 27. As shown in FIG. 3, the upper surface of the conductive layer 43 and the upper surface of the insulating layer 27 are preferably formed in the same plane, but this need not be the case. A plating base layer 46 is formed from the upper surface of the conductive layer 43 to the upper surface of the insulating layer 27, and the lower core layer 28 is formed on the plating base layer 46 by plating.
[0072]
When the conductive layer 43 is formed of a nonmagnetic conductive material, as described above, the magnetic interference between the lower core layer 28 and the upper shield layer 26 during recording and reproduction is reduced by the conventional piggyback type thin film. It can be suppressed to the same extent as a magnetic head, and the superiority as a piggyback type can be effectively maintained.
[0073]
In the present invention, the nonmagnetic conductive material is preferably selected from one or more of NiP, Cu, Al, Cr, and Au.
[0074]
Next, the formation position of the conductive layer 29 will be described below. FIG. 4 is a partial plan view of the thin film magnetic head 21 as viewed from above. In order to make the formation position of the conductive layer 29 easier to see, the upper shield layer 26, the conductive layer 43, and the lower core constituting the thin film magnetic head 29 are shown. Only the layer 28 and the back gap layer 30 are mainly shown.
[0075]
As shown in FIG. 4, the front end face 43 a of the conductive layer 29 is preferably formed so as to recede backward in the height direction (Y direction in the drawing) from the front end face 30 a of the back gap layer 30.
[0076]
In the inductive head h2 of the thin film magnetic head 21 in the present invention, a magnetic path passing through the upper magnetic pole layer 33-upper core layer 41-back gap layer 30-lower core layer 28-lower magnetic pole layer 31 is formed during recording.
[0077]
At this time, if the conductive layer 43 is a magnetic material and the front end surface 43a of the conductive layer 43 is closer to the recording medium D than the front end surface 30a of the back gap layer 30 (the direction opposite to the Y direction in the drawing) A part of the recording magnetic field is easily guided from the back gap layer 30 to the upper shield layer 26 through the lower core layer 28 and the conductive layer 43.
[0078]
Therefore, in order to prevent a part of the recording magnetic field from being guided to the upper shield layer 26 through the conductive layer 43, the front end face 43a of the conductive layer 43 is formed on the front end face 30a of the back gap layer 30. It is preferable to be formed so as to recede backward in the height direction (Y direction in the drawing). This makes it difficult for the recording magnetic field to be guided to the upper shield layer 26 via the conductive layer 43, and at the time of recording and reproduction, the lower core layer 28 is the same as in the conventional piggyback thin film magnetic head (see FIG. 18). And a thin film magnetic head capable of reducing the magnetic interference between the upper shield layer 26 and the upper shield layer 26.
[0079]
More preferably, when the front end surface 43a of the conductive layer 43 is formed behind the rear end surface 30b of the back gap layer 30 in the height direction (Y direction in the drawing), the recording magnetic field is more effective. The thin film magnetic head can be more effectively suppressed from being guided to the upper shield layer 26 through the magnetic recording medium, and can reduce the magnetic interference between the lower core layer 28 and the upper shield layer 26 during recording and reproduction. can do.
[0080]
The conductive layer 43 is preferably formed in the middle of the lower core layer 28 and the upper shield layer 26 in the track width direction (X direction in the drawing). The influence of an external magnetic field on the lower core layer 28 and the upper shield layer 26 can be weakened, and a thin film magnetic head excellent in reproducing characteristics and recording characteristics can be manufactured.
[0081]
When the conductive layer 43 is formed of a nonmagnetic conductive material, a recording magnetic field is not guided from the lower core layer 28 to the upper shield layer 26 via the conductive layer 43. Even when the front end face 43a is located closer to the recording medium D than the front end face 30a of the back gap layer 30, the lower core layer 28 and the upper shield layer 26 are compared to the case where the conductive layer 43 is made of a magnetic material. It is considered that there is no problem such as an increase in magnetic interference.
[0082]
Further, in the present invention, as shown in FIG. 5 (second embodiment of the thin film magnetic head of the present invention, which is a partial longitudinal sectional view of the thin film magnetic head), the upper core layer 41 and the back gap layer 30 are integrated. The base end portion 41 b of the upper core layer 41 may be magnetically connected to the upper surface of the lower core layer 28.
[0083]
Even in such a case, it is preferable that the front end surface 43a of the conductive layer 43 is formed so as to recede backward in the height direction (Y direction in the drawing) from the front end surface 41c of the base end portion 41b. That is, it is formed behind the rear end surface 41d of the end portion 41b in the height direction. As a result, even when the conductive layer 43 is formed of a magnetic material, it is possible to appropriately prevent the recording magnetic field from being guided from the lower core layer 28 to the upper shield layer 26 via the conductive layer 43, and to increase the future recording density. It is possible to form the thin-film magnetic head 21 having excellent recording characteristics and reproducing characteristics even in the case of manufacturing. 5 is different from FIG. 1 only in the structure of the base end portion 41b of the upper core layer 41, and the other structures are the same as those in FIG.
[0084]
The cross-sectional area in the direction parallel to the film surface of the conductive layer 43 (the surface formed by the X direction and the Y direction in the drawing) is 1 μm.²Above 500μm²It is preferably formed as follows. The cross-sectional area in the direction parallel to the film surface of the conductive layer 43 is 1 μm.²If it is smaller than this, it is difficult to form the conductive layer 43 in a predetermined shape, and it is not preferable because the lower core layer 28 and the upper shield layer 26 are not easily conductively connected.
[0085]
On the other hand, the cross-sectional area in the direction parallel to the film surface of the conductive layer 43 is 500 μm.²If the conductive layer 43 is made of a magnetic material, the lower core layer 28 and the upper shield layer 26 are more likely to interfere magnetically during recording and reproduction, and a piggyback type is obtained. It is not preferable because the superiority cannot be maintained.
[0086]
In the present invention, the cross-sectional area in the direction parallel to the film surface of the conductive layer 43 is 0.1% or more and 60% or less with respect to the cross-sectional area in the direction parallel to the film surface of the lower core layer 28. preferable. The cross-sectional area in the direction parallel to the film surface of the conductive layer 43 is preferably 0.05% or more and 30% or less with respect to the cross-sectional area in the direction parallel to the film surface of the upper shield layer 26. The reason is the same as the reason for limiting the numerical value of the cross-sectional area of the conductive layer 43 described above.
[0087]
Next, the shape of the conductive layer 43 will be described below. As shown in FIG. 4, the shape of the cross section in the direction parallel to the film surface of the conductive layer 43 is substantially square, but the shape of the cross section may be substantially round or the like. Further, the shape of the longitudinal section of the conductive layer 43 is a substantially rectangular shape in FIG. 1, but it may be another shape such as a substantially trapezoidal shape.
[0088]
Next, characteristic portions of the thin film magnetic head 21 of FIG. 1 other than the conductive layer 43 will be described below.
[0089]
As shown in FIG. 1, a conductive layer 47 is also formed in a part between the lower shield layer 23 and the upper shield layer 26, and the lower shield layer 23 and the upper shield layer 26 are conductively connected. The conductive layer 47 may be formed of a nonmagnetic conductive material or a magnetic material, but is preferably formed of a nonmagnetic conductive material.
[0090]
As described above, the lower shield layer 23 and the upper shield layer 26 are conductively connected by the conductive layer 47, so that the lower shield layer 23 and the upper shield layer 26 have the same potential, and the lower shield layer 23 and the upper shield layer 26 are connected to each other. The corrosion resistance of the shield layer 26 can be improved, the shield function of the shield layers 23 and 26 can be maintained appropriately, and the reproduction characteristics can be improved.
[0091]
Next, materials for the lower core layer 28 and the upper shield layer 26 will be described below. The lower core layer 28 is preferably formed of a magnetic material having a high saturation magnetic flux density Bs in order to appropriately cope with an increase in recording density. On the other hand, the upper shield layer 26 is preferably formed of a magnetic material having a high magnetic permeability and a low magnetostriction constant in order to improve the shielding function. Since the magnetic properties required for the lower core layer 28 and the upper shield layer 26 are different as described above, the lower core layer 28 and the upper shield layer 26 are preferably formed of different materials having necessary magnetic properties.
[0092]
The upper shield layer 26 is made of NiFe alloy (Permalloy), Sendust (Fe—Al—Si alloy), or the like. Further, it may be formed of a Co—Zr—Nb (cobalt-zirconium-niobium) amorphous alloy, a Co—Hf—Ta (cobalt-hafnium-tantalum) amorphous alloy, or the like.
[0093]
The upper shield layer 26 is formed by plating, vapor deposition or sputtering.
The lower core layer 28 is made of a NiFe alloy (permalloy), a CoFe alloy, a CoFeNi alloy, or the like. The lower core layer 28 formed of these materials is formed by electroplating. Alternatively, the lower core layer 28 has a composition formula of Fe-MO, where M is one of Al, Si, Hf, Zr, Ti, V, Nb, Ta, W, Mg, or a rare earth element. You may form with the soft magnetic material etc. which are comprised with an element or 2 or more types of elements. The lower core layer 28 made of the soft magnetic material is formed by sputtering or vapor deposition.
[0094]
In the present invention, when the lower core layer 28 and the upper shield layer 26 are both formed of a magnetic material containing Fe and a magnetic element other than Fe, the lower core layer 28 and the upper shield layer 26 are, for example, When both are made of NiFe-based alloy (permalloy), the Fe composition ratio is preferably larger on the lower core layer 28 side than on the upper shield layer 26 side. As a result, the lower core layer 28 has a high saturation magnetic flux density, while the upper shield layer 26 has a low saturation magnetic flux density, but can have a high magnetic permeability and a low magnetostriction constant.
[0095]
In the present invention, as described above, even if the lower core layer 28 and the upper shield layer 26 are formed of different materials, a part between the lower core layer 28 and the upper shield layer 26 is conductively connected by the conductive layer 43. As a result, the lower core layer 28 and the upper shield layer 26 can be set to the same potential, so that the corrosion resistance of the lower core layer 28 and the upper shield layer 26 can be improved as compared with the prior art. The thin film magnetic head 21 having excellent recording density can be formed.
[0096]
The lower core layer 28 and the upper shield layer 26 may be formed of the same magnetic material.
[0097]
A method for manufacturing the thin film magnetic head 21 shown in FIGS. 1 and 2 will be described below. First, the reproducing MR head h1 including the lower shield layer 23, the magnetoresistive effect element 25, the gap layer 24, and the upper shield layer 26 is formed on the slider 20 shown in FIG.
[0098]
Next, as shown in FIG. 6 (partially enlarged longitudinal sectional view of the thin film magnetic head during the manufacturing process), Al is formed on the upper shield layer 26.₂O_ThreeAnd SiO₂The insulating layer 27 formed by, for example, is formed by sputtering or vapor deposition. At this time, the insulating layer 27 is preferably formed with a thickness of 500 to 10,000 mm.
[0099]
Next, as shown in FIG. 7 (partially enlarged longitudinal sectional view of the thin film magnetic head during the manufacturing process), a resist layer 51 is formed on the insulating layer 27, and a hole 51a is formed in the resist layer 51 by exposure and development. To do. Then, the insulating layer 27 exposed from the hole 51a is shaved using an RIE method or an ion milling method to expose the upper surface of the upper shield layer 26 from the hole 51a. Then, the resist layer 51 is removed.
[0100]
Next, as shown in FIG. 8 (partially enlarged longitudinal sectional view of the thin film magnetic head during the manufacturing process), plating is performed from above the insulating layer 27 to the upper shield layer 26 exposed from the hole 27a formed in the insulating layer 27. The underlayer 45 is formed by sputtering or vapor deposition. The plating base layer 45 may be formed of a magnetic material such as a NiFe-based alloy, or may be formed of a nonmagnetic conductive material such as Cu.
[0101]
In the step shown in FIG. 9 (partially enlarged longitudinal sectional view of the thin film magnetic head during the manufacturing process), the lower core layer 28 is formed on the plating base layer 45 by plating. At this time, the plating layer is formed not only on the insulating layer 27 but also on the upper shield layer 26 exposed from the hole 27a of the insulating layer 27. The plating layer formed on the upper shield layer 26 via the plating base layer 27 functions as a conductive layer 43 that electrically connects the lower core layer 28 and the upper shield layer 26.
[0102]
Next, in the process shown in FIG. 10 (partial longitudinal sectional view of the thin film magnetic head during the manufacturing process), a Gd determining layer 29 made of, for example, an organic material, a lower magnetic pole layer 31, a magnetic gap layer 32, and the like are formed on the lower core layer 28. After forming the magnetic pole layer 34 composed of the upper magnetic pole layer 33, a resist layer 48 is formed on the magnetic pole layer 34 to the lower core layer 28, and then the resist layer 48 formed on the lower core layer 28 is exposed. A hole 48a is formed by development to expose the surface of the lower core layer 28.
[0103]
At this time, the front end surface 48b on the recording medium D side of the hole 48a is formed on the recording medium side (the direction opposite to the Y direction in the drawing) from the front end surface 43a on the recording medium D side of the conductive layer 43. The hole 48a is preferably provided in the resist layer 48.
[0104]
Then, as shown in FIG. 11 (partial longitudinal sectional view of the thin film magnetic head during the manufacturing process), a back gap layer 30 made of a magnetic material is formed in the hole 48a formed in the resist layer 48 by plating.
[0105]
Before the back gap layer 30 is formed, a plating base layer may be formed in the hole 48a by sputtering or the like, but even if it is not formed, the lower gap layer 30 is under the back gap layer 30. The back gap layer 30 can be appropriately grown on the lower core layer 28 by plating. Then, the resist layer 48 is removed. The front end surface 48b of the hole 48a formed in the resist layer 48 is formed closer to the recording medium than the front end surface 43a of the conductive layer 43, so that the front end surface 30a of the back gap layer 30 is formed on the conductive layer 43. It can be formed on the recording medium side (the direction opposite to the Y direction in the drawing) from the front end face 43a. Then, the resist layer 48 is removed.
[0106]
Next, after forming the insulating base layer 35 shown in FIG. 1 over the pole layer 34, the lower core layer 28, and the back gap layer 30, the first coil layer 36 is patterned on the insulating base layer 35, Further, between the conductor portions constituting the first coil layer 36 is filled with an organic insulating material layer 37 made of an organic insulating material, and then an inorganic insulating material layer 38 made of an inorganic insulating material is formed on the organic insulating material layer 37. To do. Next, the inorganic insulating material layer 38 is planarized using a CMP technique or the like, and the upper surface of the inorganic insulating material layer 38, the upper surface of the pole layer 34, and the upper surface of the back gap layer 30 are flush with each other. A second coil layer 39 is patterned on 38, and the second coil layer 39 is covered with an organic insulating material layer 40 formed of an organic material. A hole is formed on the back gap layer 30 of the organic insulating material layer 40, and then the upper core layer 41 is frame-plated from the back gap layer 30 exposed from the hole to the organic insulating material layer 40. Thus, the thin film magnetic head having the structure shown in FIG. 1 is completed.
[0107]
Next, a method in which the conductive layer 43 is formed of a magnetic material or a nonmagnetic conductive material different from the lower core layer 28 as shown in FIG. 3 will be described with reference to FIG. FIG. 12 is a partially enlarged longitudinal sectional view in the manufacturing process of the thin film magnetic head in the present invention.
[0108]
In the step shown in FIG. 12, first, a conductive layer 43 is formed on the upper shield layer 26 using a resist layer (not shown), and the resist layer is removed. Next, an insulating layer 27 is formed on the upper shield layer 26 and the conductive layer 43 by sputtering or vapor deposition. Then, the insulating layer 27 and the conductive layer 43 are etched using a CMP technique or the like until the upper surface of the insulating layer 27 and the upper surface of the conductive layer 43 are flush with each other. As a result, the upper surface of the conductive layer 43 is exposed, and then, as shown in FIG. 3, a plating base layer 46 is formed from above the insulating layer 27 to the conductive layer 43 by sputtering or vapor deposition. The lower core layer 28 is plated on the ground layer 46. Thereafter, the same steps as those shown in FIGS. 10 and 11 are performed.
[0109]
In order to form the conductive layer 43 and the insulating layer 27 on the upper shield layer 26 without using a CMP process or the like as in the process of FIG. 12, for example, the processes shown in FIGS. 13 and 14 are used. The conductive layer 43 and the insulating layer 27 may be formed.
[0110]
In the step of FIG. 13, first, a conductive layer 43 is formed on the entire surface of the upper shield layer 26. Next, a resist layer 49 is formed on the conductive layer 43 by exposure and development. The resist layer 49 may be a lift-off resist layer. Then, the conductive layer 43 not covered with the resist layer 49 is scraped off by ion etching or RIE (the dotted line portion of the conductive layer 43 shown in FIG. 13 is scraped off).
[0111]
As a result, the conductive layer 43 and the resist layer 49 are left in a part on the upper shield layer 26. Here, without removing the resist layer 49, in the step of FIG. 14, the insulating layer 27 is formed on the upper shield layer 26 where the conductive layer 43 is not formed by sputtering or vapor deposition. The insulating material layer 27 b constituting the insulating layer 27 is also formed on the upper surface of the resist layer 49. At this time, the insulating layer 27 is formed until the position of the upper surface 27 a of the insulating layer 27 is the same as the position of the upper surface 43 b of the conductive layer 43. As a result, the upper surface 43b of the conductive layer 43 and the upper surface 27a of the insulating layer 27 are flush with each other. However, the upper surface 27a of the insulating layer 27 is not necessarily flush with the position of the conductive layer 43. It may be located slightly above or below the position of the upper surface 43b. That is, even if there is a slight difference between the upper surface 43a of the conductive layer 43 and the upper surface 27a of the insulating layer 27, there is no problem as long as the lower core layer 28 can be appropriately formed on the insulating layer 27 and the conductive layer 43 by plating.
[0112]
After the insulating layer 27 is formed, the resist layer 49 is removed, and a plating base layer 46 is formed on the insulating layer 27 to the conductive layer 43. Then, the lower core layer 28 is plated on the plating base layer 46. Form.
[0113]
If the manufacturing process shown in FIGS. 13 and 14 is used, a grinding process using a CMP technique or the like can be omitted as in the process of FIG. 12, and the manufacturing process can be simplified.
[0114]
15 and 16 are process diagrams showing another method for manufacturing the conductive layer 43. 15 and 16 are partially enlarged longitudinal sectional views of the thin film magnetic head during the manufacturing process according to the present invention.
[0115]
In the process shown in FIG. 15, after the upper shield layer 26 is formed by plating, for example, a resist layer 50 is formed on the upper shield layer 26 by exposure and development. Next, the surface of the upper shield layer 26 that is not covered with the resist layer 50 is cut to a predetermined depth by ion milling, RIE, or the like (the dotted line portion shown in FIG. 15 is a portion cut away). As a result, a protrusion integrated with the upper shield layer 26 is formed from the surface of the upper shield layer 26 under the resist layer 50, and this protrusion functions as the conductive layer 43.
[0116]
Next, in the step shown in FIG. 16, an insulating layer 27 is formed on the upper shield layer 26 not covered with the resist layer 50 in the present invention by sputtering or vapor deposition. At this time, the insulating material layer 27 b constituting the insulating layer 27 is also formed on the resist layer 50. It is preferable to form the insulating layer 27 until the position of the upper surface of the insulating layer 27 is the same as the position of the upper surface of the conductive layer 43, but the upper surface of the insulating layer 27 is slightly higher than the upper surface of the conductive layer 43. It may be located above or below. Then, the resist layer 50 is removed, a plating base layer is formed on the insulating layer 27 and the conductive layer 43, and then the lower core layer 28 is formed on the plating base layer by plating.
[0117]
In the manufacturing process shown in FIGS. 15 and 16, the conductive layer 43 can be formed of the same material as the upper shield layer 26 in the same process, and the manufacturing process can be simplified.
[0118]
In order that the back gap layer 30 as shown in FIG. 5 is not formed and the base end portion 41b of the upper core layer 41 is magnetically connected to the upper surface of the lower core layer 28, first, FIG. The first coil layer 36 and the organic insulating material layer 37 and the inorganic insulating material layer 38 that cover the first coil layer 36 are formed on the lower core layer 28 without using the eleventh process, and the second coil layer is formed on the inorganic insulating material layer 38. 39 and the organic insulating material layer 40 are formed. Next, a hole that penetrates to the surface of the lower core layer 28 is formed in the organic insulating material layers 37 and 40 and the inorganic insulating material layer 38. Then, when the upper core layer 41 is formed by frame plating from above the organic insulating material layer 40 into the hole, a thin film magnetic head having the structure shown in FIG. 5 is completed.
[0119]
As shown in FIG. 5, the upper core layer 41 is patterned so that the front end surface 41c of the base end portion 41b of the upper core layer 41 is located closer to the recording medium D than the front end surface 43a of the conductive layer 43. It is preferable to form. In the present invention, by appropriately adjusting the formation position of the conductive layer 43 and the formation position of the base end portion 41b of the upper core layer 41 during each manufacturing process, the base end portion 41b of the upper core layer 41 can be easily adjusted. The front end surface 41 c of the conductive layer 43 can be positioned closer to the recording medium D than the front end surface 43 a of the conductive layer 43.
[0120]
In the present invention, the lower core layer 28 and the upper shield layer 26 can be formed of different materials. A material having a high saturation magnetic flux density Bs is selected for the magnetic material used for the lower core layer 28, and a material having a high magnetic permeability and a low magnetostriction constant is selected for the magnetic material used for the upper shield layer 26. Is preferred.
[0121]
In the present invention, Al is formed on the upper core layer 41 shown in FIGS.₂O_ThreeAfter the protective layer 42 is formed, the front end face of the thin film magnetic head 21 and the protective layer 42 is protected by one or more of DLC (diamond-like carbon) and ta-C (Tetrahedral Amorphous Carbon). The layer 44 is formed. At this time, the protective layer 44 is preferably formed with a thickness of 0.5 nm or more and 5 nm or less. This makes it possible to form a thin film magnetic head with little spacing loss and high recording density. Even if the protective layer 44 is thinly formed within the above numerical range, in the present invention, the upper shield layer 26 and the lower core layer 28 are conductively connected by the conductive layer 43, and the upper shield layer 26 and the lower core layer 28 are connected. Are made to have the same electric potential, so that a solvent used in the manufacturing process of the thin film magnetic head, moisture in the air, etc. penetrates into the protective layer 44, and the solvent and moisture penetrate the upper shield layer 26 and the lower part. Even when the core layer 28 is reached, it is possible to appropriately prevent the upper shield layer 26 and the lower core layer 28 from being corroded as compared with the conventional case.
[0122]
As described above, according to the present invention, in the so-called piggyback thin film magnetic head in which the lower core layer 28 and the upper shield layer 26 are separately formed, a single gap is provided between the lower core layer 28 and the upper shield layer 26. And the conductive layer 43 is formed, and the lower core layer 28 and the upper shield layer 26 are electrically connected to each other, whereby the lower core layer 28 and the upper shield layer 26 can be made to have the same potential, and the manufacturing process of the thin film magnetic head Even if the solvent or moisture in the air penetrates the protective layer 44 and the solvent or moisture reaches the lower core layer 28 and the upper shield layer 26, the lower core layer 28 and the upper shield layer It can suppress appropriately that 26 is corroded compared with the past.
[0123]
In the present invention, since only a part of the lower core layer 28 and the upper shield layer 26 is electrically connected by the conductive layer 43, the magnetic field between the lower core layer 28 and the upper shield layer 26 at the time of recording and reproduction is obtained. The interference is appropriately suppressed as compared with the case where the lower core layer 28 and the upper shield layer 26 are formed of the same layer, and the superiority of the piggyback type can be appropriately maintained.
[0124]
In order to keep the superiority of the piggyback type more appropriately, particularly when the conductive layer 43 is formed of a magnetic material, the front end surface 43a of the conductive layer 43 is replaced with the front end surface 30a of the back gap layer 30, or The upper core layer 41 is formed behind the front end surface 41 c of the base end portion 41 b in the height direction, whereby the recording magnetic field is guided to the upper shield layer 26 via the conductive layer 43. In other words, it is possible to more appropriately suppress magnetic interference between the lower core layer 28 and the upper shield layer 26 during recording and reproduction.
[0125]
In the present invention, the conductive layer 43 is preferably formed of the same material as that of the lower core layer 28 in the same process, whereby the process of forming the conductive layer 43 can be simplified.
[0126]
In the present invention, the lower core layer 28 and the upper shield layer 26 can be formed of different materials, thereby increasing the saturation magnetic flux density Bs of the lower core layer 28 and improving the core function. It is possible to increase the magnetic permeability of the upper shield layer 26 to enhance the shield function.
[0127]
Even when the lower core layer 28 and the upper shield layer 26 are formed of different materials, a conductive layer 43 is formed between the lower core layer 28 and the upper shield layer 26, so that the lower core layer 28 and the upper shield layer 26 are formed. The shield layer 26 can be at the same potential, and even if the protective layer 44 is formed thin to reduce the spacing loss, the corrosion resistance of the lower core layer 28 and the upper shield layer 26 can be improved, and the recording density can be increased. It is possible to manufacture a suitably excellent thin film magnetic head.
[0128]
【The invention's effect】
According to the present invention described in detail above, in a piggyback type thin film magnetic head in which a reproducing MR head and a recording inductive head are completely formed separately, a portion between the lower core layer and the upper shield layer is electrically conductive. The lower core layer and the upper shield layer can be made to have the same potential by conducting conductive connection in layers, and the solvent and moisture in the air during the manufacturing process pass through the protective layer formed of DLC or the like. Even when reaching the lower core layer or the upper shield layer, the lower core layer and the upper shield layer are hardly corroded by the battery effect, and a thin film magnetic head having superior corrosion resistance compared to the conventional one can be manufactured.
[0129]
In particular, in the present invention, the above-described corrosion problem is appropriately solved even when the protective layer is formed thin to reduce spacing loss and the solvent or the like easily reaches the lower core layer or the upper shield layer. Thus, it is possible to manufacture a thin film magnetic head that can appropriately cope with an increase in recording density.
[0130]
In the present invention, even when a conductive layer is formed between the lower core layer and the upper shield layer, magnetic interference between the lower core layer and the upper shield layer can be appropriately suppressed during recording and reproduction, and the piggyback type is achieved. It is possible to maintain an advantage.
[Brief description of the drawings]
FIG. 1 is a partial longitudinal sectional view of a thin film magnetic head according to a first embodiment of the present invention as viewed from a surface facing a recording medium;
FIG. 2 is a partially enlarged longitudinal sectional view of a thin film magnetic head in the present invention in which only the structure near the conductive layer is enlarged;
FIG. 3 is a partially enlarged longitudinal sectional view of a thin film magnetic head according to the present invention in which only the structure in the vicinity of a conductive layer different from that in FIG. 2 is enlarged;
4 is a partial plan view of the thin film magnetic head shown in FIG.
FIG. 5 is a partial longitudinal sectional view of a thin film magnetic head according to a second embodiment of the present invention as viewed from the side facing the recording medium;
FIG. 6 is a process diagram showing a manufacturing process of the thin film magnetic head in the present invention of FIGS. 1 and 2;
FIG. 7 is a process diagram performed next to FIG.
FIG. 8 is a process chart following FIG.
FIG. 9 is a process chart subsequent to FIG.
FIG. 10 is a process diagram performed subsequent to FIG.
FIG. 11 is a process diagram performed subsequent to FIG.
12 is a process diagram showing a manufacturing process of the conductive layer of the form shown in FIG.
FIG. 13 is a process diagram showing a manufacturing process of a conductive layer formed by a method different from FIG.
FIG. 14 is a process chart subsequent to FIG.
FIG. 15 is a process diagram showing another method for producing a conductive layer in the present invention;
FIG. 16 is a process chart subsequent to FIG.
FIG. 17 is a partial longitudinal sectional view of a conventional thin film magnetic head;
FIG. 18 is a partial longitudinal sectional view of a conventional piggyback thin film magnetic head;
[Explanation of symbols]
21 Thin film magnetic head
26 Upper shield layer
27 Insulating layer
28 Lower core layer
30 Back gap layer
30a Front end face (back gap layer)
41 Upper core layer
41c Front end face (of upper core layer)
43, 47 Conductive layer
43a Front end face (of conductive layer)
44 protective layer
48, 49, 50, 51 resist layer
D Recording medium
h1 MR head
h2 inductive head

Claims (12)

A reproducing head having a lower shield layer, a magnetoresistive effect element, and an upper shield layer, a lower core layer facing the upper shield layer via an insulating layer, a magnetic gap layer, and an upper core layer, In a thin film magnetic head comprising a recording head having the lower core layer and a coil layer formed between the upper core layers,
A part between the upper shield layer and the lower core layer is conductively connected by a conductive layer formed of a magnetic material, and a base end portion of the upper core layer is magnetically formed on the lower core layer at the rear in the height direction. The thin-film magnetic head is connected, and the front end surface of the conductive layer is formed behind the front end surface of the base end portion in the height direction. A reproducing head having a lower shield layer, a magnetoresistive effect element, and an upper shield layer, a lower core layer facing the upper shield layer via an insulating layer, a magnetic gap layer, and an upper core layer, In a thin film magnetic head comprising a recording head having the lower core layer and a coil layer formed between the upper core layers,
A part of the upper shield layer and the lower core layer is electrically connected by a conductive layer formed of a magnetic material, and the upper core layer and the lower core layer are magnetically connected via a back gap layer at the rear in the height direction. And the front end surface of the conductive layer is formed behind the front end surface of the back gap layer in the height direction.   3. The thin film magnetic head according to claim 1, wherein the conductive layer is made of the same material as the lower core layer. 4. The thin film magnetic head according to claim 1, wherein a cross-sectional area in a direction parallel to the film surface of the conductive layer is 1 μm ² or more and 500 μm ² or less.   5. The thin film magnetic head according to claim 1, wherein the lower core layer and the upper shield layer are formed of different magnetic materials.   The thin film magnetic head according to claim 1, wherein a protective layer is formed on a front end surface of the thin film magnetic head, and the thickness of the protective layer is 0.5 nm or more and 5 nm or less.   7. The thin film magnetic head according to claim 6, wherein the protective layer is formed of one or more of DLC (Diamond Like Carbon) and ta-C (Tetrahedral Amorphous Carbon). In the method of manufacturing a thin film magnetic head,
(A) forming a read head having a lower shield layer, a magnetoresistive effect element, and an upper shield layer;
(B) forming a conductive layer made of a magnetic material on a part of the upper shield layer, and forming an insulating layer around the conductive layer;
(C) forming a lower core layer from above the insulating layer to the conductive layer;
(D) forming a coil layer and an upper core layer on the lower core layer, and forming a recording head having the lower core layer, the coil layer, and the upper core layer;
The front end surface of the base end portion of the upper core layer magnetically connected to the lower core layer in the step (d), or the base end portions of the lower core layer and the upper core layer in the step (d) A method of manufacturing a thin film magnetic head, comprising forming a front end face of a back gap layer formed therebetween so as to be positioned closer to a recording medium than a front end face of the conductive layer. 9. The method of manufacturing a thin film magnetic head according to claim 8, comprising the following steps instead of the steps (b) and (c).
(E) forming an insulating layer on the upper shield layer, forming a hole penetrating to the upper shield layer in the insulating layer, and forming a plating base layer from the inside of the hole to the insulating layer; ,
(F) A step of plating a lower core layer on the plating base layer and forming a conductive layer integrated with the lower core layer in the hole.   10. The method of manufacturing a thin film magnetic head according to claim 8, wherein the lower core layer is formed of a magnetic material different from that of the upper shield layer in the steps (c) and (f).   The protective layer is formed on the surface facing the recording medium after the step (d), and the thickness of the protective layer is 0.5 nm or more and 5 nm or less. A manufacturing method of the thin film magnetic head according to 1. 12. The method of manufacturing a thin film magnetic head according to claim 11, wherein the protective layer is formed of one or more of DLC (diamond-like carbon) and ta-C (Tetrahedral Amorphous Carbon).

Images