Thin film magnetic head including coil wound in toroidal shape and method for manufacturing the same

A thin film magnetic head and a method for manufacturing the same is provided, wherein first coil pieces and second coil pieces provided one above the other with a magnetic pole layer therebetween are electrically connected to each other with reliability and with ease, and the above-described magnetic pole layer can be provided on a flattened surface. A laminate provided on a coil insulation layer can be formed on a flattened surface and, therefore, the above-described magnetic pole layer can be formed into a predetermined shape. As a result, the track width can have a predetermined dimension, and the second coil pieces provided on the above-described laminate can be reliably, easily connected to the top surfaces of connection layers exposed at the top surface of the coil insulating layer.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a thin film magnetic head for recording used in, for example, a floating magnetic head. In particular, the present invention relates to a thin film magnetic head and a method for manufacturing the same, wherein first coil pieces and second coil pieces provided one above the other with a magnetic layer therebetween are electrically connected to each other with reliability and with ease, and the magnetic layer can be provided on a flattened surface.

2. Description of the Related Art

Each of known documents, Japanese Unexamined Patent Application Publication No. 11-273028, Japanese Unexamined Patent Application Publication No. 2000-311311, Japanese Unexamined Patent Application Publication No. 2002-170205, and U.S. Pat. No. 6,335,846 B1, discloses a configuration of a coil layer wound in a toroidal shape around a core constituting an inductive head (recording head).

Preferably, the above-described coil layer is allowed to have a toroidal shape in order to make full use of a three-dimensional space around the above-described core and, thereby, it is expected that miniaturization of the inductive head can be realized and the magnetization efficiency becomes excellent.

However, the toroidal coil structures described in the above-described patent documents have the following problems.

Each of these documents describes that lower coil layers provided under a core layer (for example, an upper core layer) and upper coil layers provided on the above-described core layer are electrically connected via connection layers, and this connection layer is formed by, for example, digging a through hole connected to the above-described lower coil layer in an insulating layer provided on the lower coil layer and, thereafter, growing a layer of plating from this through hole.

However, a plurality of lower coil layers, described above, are densely provided in a narrow region, and the two-dimensional size of the above-described connection layer is smaller than the width of the lower coil layer in each document. Consequently, it is practically difficult to form the through hole connected to each lower coil layer if significantly high-precise etching technique is not available. Furthermore, the above-described etching has a high risk of damaging the lower coil layer.

With respect to the growth of the connection layer by plating from the above-described through hole, if the above-described through hole is not properly dug to reach the top surface of the lower coil layer, growth of plating cannot be appropriately performed. If formation of the above-described connection layer by plating is terminated, for example, midway through the above-described through hole, electrical connection to the upper coil layer tends to become unstable.

The top surface of the insulating layer provided on the above-described lower coil layer is undulated due to, for example, height difference between the above-described lower coil layer and the lower core layer. Since the upper core layer must be formed on the top surface of the above-described insulation layer having such undulations, the above-described upper core layer cannot be patterned into a predetermined shape. In addition, it is essentially difficult to form the above-described through hole having a predetermined shape in the insulating layer having undulations. Furthermore, since the upper coil layers provided on the above-described upper core layer with another insulating layer therebetween are also provided on a surface having undulations, electrical connection between the above-described upper coil layers and the lower coil layers via the connection layers tends to become unstable.

SUMMARY OF THE INVENTION

Accordingly, the present invention is for overcoming the above-described known problems. In particular, it is an object of the present invention to provide a thin film magnetic head and a method for manufacturing the same, wherein first coil pieces and second coil pieces provided one above the other with a magnetic layer therebetween are electrically connected to each other with reliability and with ease, and the above-described magnetic layer can be provided on a flattened surface.

A thin film magnetic head according to an aspect of the present invention includes a protuberance layer having a predetermined length in the height direction from a surface facing a recording medium and a back gap layer located at a predetermined distance in the height direction from the rear end surface in the height direction of the above-described protuberance layer, each provided on a lower core layer extending in the height direction from the above-described facing-surface side, a magnetic layer connecting between the above-described protuberance layer and the back gap layer, and a coil layer wound in a toroidal shape around the above-described magnetic layer; wherein a plurality of first coil pieces extending in the direction intersecting the above-described magnetic layer are provided at predetermined spacings in the height direction in a space enclosed with the above-described lower core layer, the above-described protuberance layer, and the back gap layer, connection layers are provided while protruding from the end portions in the track-width direction of each first coil piece, and the above-described first coil pieces are covered with a coil insulating layer; all of the top surface of the above-described coil insulating layer, the top surface of the above-described protuberance layer, the top surface of the above-described back gap layer, and the top surfaces of the above-described connection layers are provided as the same flattened surface; the above-described magnetic layer is provided on the flattened surface of the above-described coil insulating layer, the protuberance layer, and the back gap layer; a plurality of second coil pieces crossing over the above-described magnetic layer are provided on the above-described magnetic layer with an insulating layer therebetween; and the end portions in the track-width direction of each second coil piece are electrically connected to the top surfaces of connection layers exposed at the above-described flattened surface, and the end portions of the above-described first coil pieces adjacent to each other are connected via the above-described second coil pieces, so that the above-described coil layer wound in a toroidal shape is provided.

In the above-described aspect, the above-described first coil pieces are provided in the space enclosed with the lower core layer, the protuberance layer, and the back gap layer, the top surface of the coil insulating layer covering the above-described first coil pieces is provided as a flattened surface, and the top surfaces of the connection layers protruding from the end portions of the above-described first coil pieces are exposed at surfaces flush with this flattened surface.

Therefore, the magnetic layer provided on the above-described coil insulating layer can be formed on the flattened surface, and the above-described magnetic layer can be thereby formed into a predetermined shape. As a result, the track width Tw can have a predetermined dimension, and the second coil pieces provided on the above-described magnetic layer and the top surfaces of the connection layers exposed at the top surface of the above-described coil insulating layer can be reliably, easily connected. Since the top surfaces of the coil insulating layer and the connection layers are flattened, slimming of the whole thin film magnetic head can be achieved.

In a thin film magnetic head according to another aspect of the present invention, a plurality of first coil pieces extending in the direction intersecting the above-described magnetic layer are provided in a space enclosed with the above-described lower core layer, the above-described protuberance layer, and the back gap layer, and the above-described first coil pieces are covered with a coil insulating layer; the above-described magnetic layer is provided on the above-described coil insulating layer, the protuberance layer, and the back gap layer, the above-described magnetic layer is covered with an insulating layer having the top surface provided as a flattened surface; a plurality of second coil pieces crossing over the above-described magnetic layer are provided on the flattened surface of this insulating layer; and the top surfaces of connection layers electrically connected to the end portions in the track-width direction of each first coil piece are exposed at surfaces flush with the above-described flattened surface, the end portions in the track-width direction of each second coil piece are electrically connected to the top surfaces of the above-described connection layers and, thereby, the end portions of the above-described first coil pieces adjacent to each other are connected via the above-described second coil pieces, so that the above-described coil layer wound in a toroidal shape is provided.

In the present aspect, the insulating layer covering the above-described magnetic layer is provided as a flattened surface, and the top surfaces of the connection layers electrically connected to the end portions in the track-width direction of each first coil piece are exposed at surfaces flush with this flattened surface.

Consequently, the second coil piece provided on the above-described insulating layer can be formed into a predetermined shape and, in addition, the second coil pieces and the first coil pieces can be electrically connected via the connection layers with reliability and with ease. In the present aspect, there is a further advantage in that insulation between the above-described second coil pieces and the above-described magnetic layer can be excellently maintained.

In a thin film magnetic head according to another aspect of the present invention, a plurality of first coil pieces extending in the direction intersecting the above-described magnetic layer are provided in a space enclosed with the above-described lower core layer, the above-described protuberance layer, and the back gap layer, lower connection layers are provided while protruding from the end portions in the track-width direction of each first coil piece, and the above-described first coil pieces are covered with a coil insulating layer; all of the top surface of the above-described coil insulating layer, the top surface of the above-described protuberance layer, the top surface of the above-described back gap layer, and the top surfaces of the above-described lower connection layers are provided as the same flattened surface; the above-described magnetic layer is provided on the above-described flattened surface of the above-described coil insulating layer, the protuberance layer, and the back gap layer, and upper connection layers electrically connected to the above-described lower connection layers are provided; the above-described magnetic layer is covered with an insulating layer having the top surface provided as a flattened surface, and the top surfaces of the above-described upper connection layers are exposed at surfaces flush with the above-described flattened surface; and a plurality of second coil pieces crossing over the above-described magnetic layer are provided on the flattened surface of the above-described insulating layer, the end portions in the track-width direction of each second coil piece are electrically connected to the upper connection layers exposed at the above-described flattened surface, and the end portions of the above-described first coil pieces adjacent to each other are connected via the above-described second coil pieces, so that the above-described coil layer wound in a toroidal shape is provided.

In the present aspect, the top surface of the coil insulating layer covering the above-described first coil pieces is provided as a flattened surface, the top surface of the lower connection layers electrically connected to the end portions of the above-described first coil pieces are exposed at surfaces flush with this flattened surface, the top surface of the insulating layer covering the top surface of the above-described magnetic layer is provided as a flattened surface, and the top surfaces of the upper connection layers electrically connected to the above-described lower connection layers are exposed at surfaces flush with this flattened surface.

Therefore, the magnetic layer provided on the above-described coil insulating layer can be formed on the flattened surface, and the above-described magnetic layer can be thereby formed into a predetermined shape. Consequently, the track width Tw can have a predetermined dimension. Since the second coil pieces provided on the above-described insulating layer can be formed on the flattened surface, the above-described second coil piece can be formed into a predetermined shape and, in addition, the above-described second coil pieces and the first coil pieces can be electrically connected via the connection layers with reliability and with ease.

In the present invention, a laminated structure composed of a lower magnetic pole layer, a gap layer, and an upper magnetic pole layer for serving as the above-described magnetic layer in that order from the bottom may be provided on the above-described protuberance layer, and a track width Tw may be determined by the width dimension in the track-width direction of the above-described laminated structure in the above-described facing-surface.

In the present invention, the laminated structure including a lower magnetic pole layer, a gap layer, and an upper magnetic pole layer may be connected to the lower core layer with the above-described protuberance layer therebetween in the side of the surface facing the recording medium and with the back gap layer therebetween in the height direction side. Therefore, the above-described magnetic layer may be formed into a planar shape on the above-described first coil pieces, the track width Tw may easily have a predetermined dimension, and reduction of the magnetic path length may be achieved.

In the present invention, the above-described protuberance layer may be a magnetic pole end layer in which at least a lower magnetic pole layer, a gap layer formed from a non-magnetic metal material, and an upper magnetic pole layer are provided by plating in that order from the bottom and in which a track width Tw may be regulated by the width dimension in the track-width direction in the facing-surface, and the above-described magnetic layer may be laminated on the above-described magnetic pole end layer.

In the present invention, the above-described magnetic pole end layer may be provided at the end portion of the above-described lower core layer in the side of the surface facing the recording medium, and the above-described magnetic layer may serve as the upper core layer connecting the height side of the above-described lower core layer and the above-described magnetic pole end layer. The above-described first coil pieces and the above-described second coil pieces may be wound around the above-described magnetic layer for serving as the upper core layer.

When the above-described magnetic layer serves as the upper core layer in the present invention, preferably, the saturation magnetic flux density of the above-described magnetic layer is lower than that of the above-described upper magnetic pole layer in order to prevent magnetic recording outside the recording track width.

In the present invention, with respect to at least one pair of the above-described first coil pieces adjacent to each other, the distance between the end portions adjacent to each other in the height direction of the above-described first coil pieces is larger than a minimum distance between the above-described first coil pieces in the region overlapping the above-described magnetic layer.

With respect to an inductive thin film magnetic head, preferably, the volume of a magnetic circuit for flowing a magnetic flux is reduced and, thereby, inductance is reduced. Consequently, the length in the height direction of the above-described magnetic pole layer must be decreased, and the distance between the above-described first coil pieces in the region overlapping the above-described magnetic layer is also decreased. At this time, by increasing the distance between the end portions adjacent to each other in the height direction of the above-described first coil pieces, as in the present invention, the end portions of the above-described first coil pieces and the end portions of the above-described second coil pieces can be easily, reliably connected.

When the above-described plurality of first coil pieces include portions parallel to each other in the region overlapping the above-described magnetic layer, the magnetic field induced from the above-described coil layer to the above-described magnetic layer is preferably stabilized.

With respect to at least one pair of the above-described second coil pieces adjacent to each other, preferably, the distance between the end portions adjacent to each other in the height direction of the above-described second coil pieces is larger than a minimum distance between the above-described second coil pieces in the region overlapping the above-described magnetic layer for a similar reason.

In this case as well, preferably, the above-described plurality of second coil pieces include portions parallel to each other in the region overlapping the above-described magnetic layer.

In the present invention, preferably, the length dimension of the above-described second coil piece in a first direction orthogonal to the direction of a current flow is larger than the length dimension of the above-described first coil piece in the above-described first direction, and the film thickness of the above-described second coil piece is larger than the film thickness of the above-described first coil piece in order to reduce the heat generation of the above-described coil layer.

A method for manufacturing a thin film magnetic head according to another aspect of the present invention includes the steps of (a) forming a lower core layer extending in the height direction from the side of a surface facing a recording medium, (b) forming a coil insulating substrate layer on the above-described lower core layer and, thereafter, forming a plurality of first coil pieces extending in the direction intersecting the above-described height direction, at predetermined spacings in the height direction, on the above-described coil insulating substrate layer in a predetermined region, (c) forming a protuberance layer from the above-described facing-surface toward the height direction on the above-described lower core layer while the location of the protuberance layer is suitable for avoiding contact with the above-described first coil pieces, forming a back gap layer on the above-described lower core layer while the location of the back gap layer is at a distance in the height direction from the rear end surface in the height direction of the above-described protuberance layer and is suitable for avoiding contact with the above-described first coil pieces, and forming connection layers protruding from the end portions in the track-width direction of each first coil piece, (d) covering the above-described first coil pieces with a coil insulating layer and, thereafter, polishing the above-described coil insulating layer, the protuberance layer, the back gap layer, and the connection layers until the top surface of the above-described protuberance layer, the top surface of the above-described coil insulating layer, the top surface of the back gap layer, and the top surfaces of the connection layers are provided as the same flattened surface, (e) forming a magnetic layer on the above-described flattened surface of the above-described coil insulating layer, the protuberance layer, and the back gap layer to connect between the above-described protuberance layer and the back gap layer, and (f) forming an insulating layer on the above-described magnetic layer, forming a plurality of second coil pieces on this insulating layer while the second coil pieces cross over the above-described magnetic layer, connecting the end portions in the track-width direction of each second coil piece to the top surfaces of the connection layers exposed at the above-described flattened surface, and connecting the end portions of the above-described first coil pieces adjacent to each other via the above-described second coil pieces, so that a coil layer wound in a toroidal shape is provided.

According to the method for manufacturing a thin film magnetic head of the present aspect, the above-described first coil pieces are formed on the lower core layer with the coil insulating substrate layer therebetween in the above-described step (b), and the protuberance layer, the back gap layer, and the connection layers are formed in the above-described step (c). Consequently, after the above-described first coil pieces are covered with the coil insulating layer, a polishing step can be performed in order that the top surface of the above-described protuberance layer, the top surface of the above-described coil insulating layer, the top surface of the back gap layer, and the top surfaces of the connection layers are provided as the same flattened surface in the above-described step (d).

As a result, the magnetic layer can be formed on the above-described flattened coil insulating layer, protuberance layer, and back gap layer to connect between the protuberance layer and the back gap layer in the above-described step (e). Since the above-described magnetic layer can be formed into a predetermined shape and, in addition, the top surfaces of the above-described connection layers are exposed at the same flattened surface as the top surface of the above-described coil insulating layer, the end portions in the track-width direction of the above-described second coil pieces can be electrically connected to the top surfaces of the above-described connection layers with reliability and with ease in the above-described step (f).

In the present aspect, preferably, the above-described protuberance layer, the back gap layer, and the connection layers are simultaneously formed from the same material in the above-described step (c) in order to speed up the manufacturing process and facilitate the formation of the above-described connection layers.

In the present aspect, instead of the above-described step (f), the manufacturing method may include the steps of (g) forming upper connection layers on the above-described connection layers while the upper connection layers extend to the locations higher than the top surface of the above-described magnetic layer, (h) covering the above-described magnetic layer with an insulating layer and, thereafter, polishing the above-described insulating layer and the upper connection layers until the top surfaces of the above-described upper connection layers and the top surface of the above-described insulating layer are provided as the same flattened surface, and (i) forming a plurality of second coil pieces on the flattened surface of the above-described insulating layer while the second coil pieces cross over the above-described magnetic layer, connecting the end portions in the track-width direction of each second coil piece to the top surfaces of the upper connection layers exposed at the above-described flattened surface, and connecting the end portions of the above-described first coil pieces adjacent to each other via the above-described second coil pieces, so that a coil layer wound in a toroidal shape is provided.

In the present aspect, the polishing step is performed until the top surfaces of the above-described upper connection layers are provided as the same flattened surface as the top surface of the insulating layer covering the above-described magnetic layer. As a result, the above-described second coil pieces can be formed on the flattened surface and, in addition, the end portions of the above-described second coil pieces can be electrically connected to the end portions of the above-described first coil pieces via the upper connection layers and the connection layers with reliability and with ease.

According to the present invention described above in detail, the first coil pieces are provided in the space enclosed with the lower core layer, the protuberance layer, and the back gap layer, the top surface of the coil insulating layer covering the above-described first coil pieces is provided as a flattened surface, and the top surfaces of the connection layers protruding from the end portions of the above-described first coil pieces are exposed at surfaces flush with this flattened surface.

Therefore, the magnetic pole layer provided on the above-described coil insulating layer can be formed on the flattened surface, and the above-described magnetic pole layer can be thereby formed into a predetermined shape. As a result, the track width Tw can have a predetermined dimension, and the second coil pieces provided on the above-described magnetic pole layer and the top surfaces of the connection layers exposed at the top surface of the above-described coil insulating layer can be reliably, easily connected. Furthermore, the insulating layer can be provided as a flattened surface on the above-described magnetic pole layer, and the top surfaces of the upper connection layers electrically connected to the above-described connection layers (lower connection layers) can be exposed at this flattened surface. In such a case, the above-described second coil pieces can be formed on the flattened surface, the second coil piece can be formed into a predetermined shape and, in addition, the above-described second coil pieces can be further reliably, easily connected to the top surfaces of the above-described upper connection layers.

Furthermore, by increasing the distance between the end portions adjacent to each other in the height direction of the above-described first coil pieces and/or the above-described second coil pieces, as in the present invention, the end portions of the above-described first coil pieces and the end portions of the above-described second coil pieces can be easily, reliably connected.

When a plurality of the above-described first coil pieces and/or the above-described second coil pieces include portions parallel to each other in the region overlapping the above-described magnetic pole layer, the magnetic field induced from the above-described coil layer to the above-described magnetic pole layer is stabilized.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1is a partial vertical sectional view showing the structure of a thin film magnetic head according to the first embodiment of the present invention.FIG. 2is a partial front view of the thin film magnetic head shown inFIG. 1wherein a protuberance layer32, a protective layer60, an MR head, and the like are not shown in the diagram, and a first coil piece, a second coil piece, and the like provided at the locations closest to a surface facing a recording medium are viewed from the side of the surface facing the recording medium.FIG. 3is a partial plan view showing a coil structure of the thin film magnetic head shown inFIG. 1.FIG. 4is a partial perspective view of a magnified part of the structure of the thin film magnetic head shown inFIG. 1.

Hereafter the X direction shown in the drawing is referred to as the track-width direction, and the Y direction shown in the drawing is referred to as the height direction. The Z direction shown in the drawing is the direction of movement of the recording medium (magnetic disk). A front end surface (a leftmost surface shown inFIG. 1) of the thin film magnetic head is referred to as “a surface facing a recording medium”. With respect to each layer, “a front end surface” refers to a left-side surface shown inFIG. 1, and “a rear end surface” refers to a right-side surface shown inFIG. 1.

The thin film magnetic head described with reference to the drawings is a thin film magnetic head including a combination of a recording head (may be referred to as an inductive head) and a playback head (may be referred to as an MR head). However, the thin film magnetic head may be simply composed of the recording head.

Reference numeral20denotes a substrate formed from alumina-titanium carbide (Al2O3—TiC) or the like, and an Al2O3layer21is provided on the above-described substrate20.

A lower shield layer22formed from a NiFe-based alloy, sendust, or the like is provided on the above-described Al2O3layer21, and a lower gap layer23formed from Al2O3or the like is provided on the above-described lower shield layer22.

A magnetoresistance effect element24typified by a GMR element, e.g., a spin-valve type thin film element, having a predetermined length in the height direction (the Y direction shown in the drawing) from the surface facing the recording medium is provided on the above-described lower gap layer23. Electrode layers25long-extending in the height direction (the Y direction shown in the drawing) are provided in both sides of the above-described magnetoresistance effect element24in the track-width direction (the X direction shown in the drawing).

An upper gap layer26formed from Al2O3or the like is provided on the above-described magnetoresistance effect element24and the electrode layers25, and an upper shield layer27formed from a NiFe-based alloy or the like is provided on the above-described upper gap layer26.

The layers from the above-described lower shield layer22to the above-described upper shield layer27are referred to as the playback head (may be referred to as the MR head).

As shown inFIG. 1, a separation layer28formed from Al2O3or the like is provided on the above-described upper shield layer27. The above-described upper shield layer27and the separation layer28may not be provided, and a following lower core layer29may be provided on the above-described upper gap layer26. In such a case, the above-described lower core layer29doubles as the upper shield layer.

InFIG. 1, the lower core layer29is provided on the above-described separation layer28. The above-described lower core layer29is formed from a magnetic material, e.g., a NiFe-based alloy. The above-described lower core layer29has a predetermined length dimension in the height direction (the Y direction shown in the drawing) from the surface facing the recording medium. A non-magnetic insulating material layer31is provided at the rear in the height direction of the rear end surface29aof the above-described lower core layer29and in both sides of the above-described lower core layer29in the track-width direction (the X direction shown in the drawing). As shown inFIG. 1, the surface of each of the above-described lower core layer29and the non-magnetic insulating material layer31is a continuous flattened surface.

The protuberance layer32having a predetermined length L1(refer toFIG. 4) in the height direction (the Y direction shown in the drawing) from the surface facing the recording medium is provided on the above-described lower core layer29. A back gap layer33is provided on the above-described lower core layer29while the location of the back gap layer is at a predetermined distance in the height direction (the Y direction shown in the drawing) from the rear end surface32ain the height direction of the above-described protuberance layer32.

The above-described protuberance layer32and the back gap layer33are formed from a magnetic material, and these may be formed from the same material as that for the above-described lower core layer29or be formed from another material. Each of the above-described protuberance layer32and the back gap layer33may be a single layer or may has a multilayer laminated structure. The above-described protuberance layer32and the back gap layer33are magnetically connected to the above-described lower core layer29.

As shown inFIG. 1, a coil insulating substrate layer34is provided between the above-described protuberance layer32and the back gap layer33on the lower core layer29, and a plurality of first coil pieces55parallel to each other are provided on the above-described coil insulating substrate layer34while the first coil pieces55are extended parallel to the track-width direction (the X direction shown in the drawing) and are arranged side by side in the height direction, as shown inFIG. 3. Each of the first coil pieces55may be extended in the track-width direction (the X direction shown in the drawing) while being inclined toward the height direction.

The above-described first coil pieces55are covered with a coil insulating layer36formed from an inorganic insulating material, e.g., Al2O3. As shown inFIG. 1, the top surface of the above-described protuberance layer32, the top surface of the coil insulating layer36, and the top surface of the back gap layer33are a continuous flattened surface along the reference surface A shown inFIG. 1.

As shown inFIG. 2andFIG. 3, connection layers61having electrical conductivity are provided as protrusions in the track-width direction (the X direction shown in the drawing) on the end portions55aof the above-described first coil pieces55. The two-dimensional shape (that is, the shape of a surface cut from the direction parallel to the X-Y plane) of the above-described connection layer61can be selected from various shapes, e.g., an ellipse as shown inFIG. 3, a circle, a square, a rectangle, and a rhombus. Preferably, the above-described connection layer61is formed from the same material as that for the above-described protuberance layer32and the back gap layer33from the viewpoint of the manufacturing process, as described below. However, the material may be different from that for the above-described protuberance layer32and the back gap layer33. The above-described connection layer61may have a single-layer structure or a multilayer laminated structure. The above-described connection layers61are in the condition of being electrically connected to the end portions55aof the above-described first coil pieces55. The term “electrically connected” refers to a condition in which there is electrical continuity between two layers regardless of direct connection or indirect connection. Hereafter the same holds true.

with respect to the above-described connection layers61, as is clear fromFIG. 3, the first coil piece55provided at the location closest to the surface facing the recording medium is provided with the above-described connection layer61simply on the upper-side end portion shown in the drawing, and other first coil pieces55are provided with the above-described connection layers61on both end portions in the track-width direction (the X direction shown in the drawing).

As shown inFIG. 2, the top surfaces61aof the connection layers61provided on the end portions55ain the track-width direction (the X direction shown in the drawing) of each first coil piece55are flush with the above-described reference surface A. That is, with respect to the thin film magnetic head shown inFIG. 1, all of the top surface of the above-described protuberance layer32, the top surface of the coil insulating layer36, the top surface of the back gap layer33, and the top surfaces61aof the connection layers61are provided as the same flattened surface.

As shown inFIG. 1, a Gd-determining layer38is provided from the location at a predetermined distance in the height direction (the Y direction shown in the drawing) from the above-described surface facing the recording medium toward the height direction on the flattened surface of the above-described protuberance layer32and the coil insulating layer36.

In the embodiment shown inFIG. 1, the front end surface38aof the above-described Gd-determining layer38is located on the protuberance layer32, and the rear end surface38bof the above-described Gd-determining layer38is located on the coil insulating layer36.

As shown inFIG. 1, a lower magnetic pole layer39and a gap layer40are provided in that order from the bottom on the protuberance layer32from the surface facing the recording medium to the above-described front end surface38aof the above-described Gd-determining layer38, on the coil insulating layer36from the rear end surface38bof the above-described Gd-determining layer38toward the height direction, and on the above-described back gap layer33. The above-described lower magnetic pole layer39and the gap layer40are provided by plating.

As shown inFIG. 1, an upper magnetic pole layer41for serving as a magnetic layer in the present invention is provided by plating on the above-described gap layer40and the Gd-determining layer38, and an upper core layer42is provided by plating on the above-described upper magnetic pole layer41. The above-described upper magnetic pole layer41is directly or indirectly connected to the above-described lower core layer29with the above-described back gap layer33therebetween. The above-described lower magnetic pole layer39, the gap layer40, and the upper magnetic pole layer41constitute a laminated structure of the present invention.

In the present embodiment, a laminate62is composed of four layers of the above-described lower magnetic pole layer39, the gap layer40, the upper magnetic pole layer41, and the upper core layer42.

As shown inFIG. 1andFIG. 2, an insulating layer58formed from an insulating material, e.g., Al2O3, is provided on the above-described upper core layer42. Preferably, the above-described insulating layer58is formed from an inorganic insulating material. This insulating layer58is also provided on the coil insulating layer36extending in both sides of the above-described laminate62in the track-width direction (the X direction shown in the drawing). As shown inFIG. 2, insulating layers63formed from an organic insulating material, e.g., a resist, are provided over both end portions in the track-width direction (the X direction shown in the drawing) of the above-described insulating layer58and both sides in the track-width direction of the above-described laminate62. The insulating layer58formed from the inorganic insulating material is provided by a sputtering method or the like. Since the above-described insulating layer58can have a film thickness smaller than that of the insulating layer63formed from the organic insulating material, the laminate62and the second coil pieces56described below can be brought close to each other, and the magnetization efficiency can be increased. In addition, insulation between the above-described laminate62and the second coil pieces56can be excellently maintained in both sides of the above-described laminate62in the track-width direction.

As shown inFIG. 1toFIG. 3, a plurality of second coil pieces56parallel to each other are provided on the above-described insulating layers58and63while being arranged side by side in the height direction. The second coil pieces56are extended in the track-width direction (the X direction shown in the drawing) while being inclined toward the height direction (the Y direction shown in the drawing). Each of the second coil pieces56may be provided while being extended in the direction parallel to the track-width direction (the X direction shown in the drawing).

As shown inFIG. 3, the above-described first coil pieces55and the second coil pieces56are non-parallel to each other. As shown inFIG. 2andFIG. 3, the left end portion55ain the track-width direction of the first coil piece55and the left end portion56ain the track-width direction of the second coil piece56face each other in the film thickness direction (the Z direction shown in the drawing) of the laminate62, and the left end portion55aand the left end portion56aare electrically connected to each other via the connection layer61. The right connection layer61indicated by a dotted line shown inFIG. 2electrically connects the right end portion of the first coil piece55located at the back (the Y direction shown in the drawing) of the first coil piece55visible in the drawing and the right end portion56bof the second coil piece56visible in the drawing.

As described above, in the thin film magnetic head shown inFIG. 1, the end portion in the track-width direction of the first coil piece55and the end portion in the track-width direction of the second coil piece56facing one above the other in the film thickness direction of the above-described laminate62are electrically connected to each other via the connection layer61and, thereby, a toroidal coil structure57is provided.

A layer denoted by reference numeral60shown inFIG. 1is a protective layer formed from Al2O3or the like, and a layer denoted by reference numeral59shown inFIG. 1andFIG. 3is a lead layer. The above-described lead layer59is integrally formed with the second coil piece56located at the front end in the height direction.

The features of the thin film magnetic head shown inFIG. 1will be described below.

In the thin film magnetic head shown inFIG. 1, the plurality of first coil pieces55are provided in the space enclosed with the above-described lower core layer29, the protuberance layer32, and the back gap layer33. The space in which the above-described first coil pieces55can be provided is appropriately formed by protruding the protuberance layer32and the back gap layer33on the above-described lower core layer29. In particular, when the above-described protuberance layer32and the back gap layer33are provided by plating, the above-described protuberance layer32and the back gap layer33can have large thicknesses. Consequently, the space enclosed with the above-described lower core layer29, the protuberance layer32, and the back gap layer33is allowed to become wide, and the above-described first coil pieces55having predetermined film thicknesses are easily provided.

The connection layers61are protruded from the end portions55ain the track-width direction of each first coil piece55. The top surfaces of the connection layers61are flush with the top surface of the above-described protuberance layer32, the top surface of the back gap layer33, and the top surface of the coil insulating layer36and, therefore, the top surfaces of the above-described connection layers61are in the condition of being exposed at the above-described flattened surface.

Consequently, in the thin film magnetic head shown inFIG. 1, the laminate62provided on the above-described protuberance layer32, the coil insulating layer36, and the back gap layer33can be formed on the above-described flattened surface, and the above-described laminate62can be formed into a predetermined shape. Therefore, the track-width dimension Tw determined by the width dimension in the track-width direction (the X direction shown in the drawing) of the upper magnetic pole layer41of the above-described laminate62in the surface facing the recording medium can be highly precisely adjusted at a predetermined dimension. In the present embodiment, the above-described track width Tw can be adjusted at within the range of 0.1 μm to 0.3 μm.

In the thin film magnetic head shown inFIG. 1, since the top surfaces61aof the above-described connection layers61are exposed at the same flattened surface as the above-described coil insulating layer36, the end portions in the track-width direction (the X direction shown in the drawing) of the above-described second coil pieces56can be electrically connected onto the above-described connection layers61with reliability and with ease. Consequently, poor electrical contact between the above-described first coil pieces55and the second coil pieces56can be prevented.

Since all of the top surfaces of the coil insulating layer36, the top surface of the protuberance layer32, the top surface of the back gap layer33, and the top surfaces of the connection layers61are provided as the same flattened surface, the slimming of the whole thin film magnetic head can be facilitated.

Since the above-described laminate62having a linear shape parallel to the layer surface connects between the above-described protuberance layer32and back gap layer33and, thereby, the magnetic path is provided, reduction of the magnetic path length can be realized. Since the magnetic path length can be reduced, the speed of magnetic field reversal can be increased, and a thin film magnetic head having excellent high-frequency characteristics can be provided.

The above-described first coil piece55and the second coil piece56are formed from Cu or Au having excellent electrical conductivity. The above-described connection layer61may not be formed from the same material as that for the above-described first coil piece55and the second coil piece56, and may be formed from a magnetic material or the like, as long as the material has electrical conductivity. Preferably, the above-described connection layer61is formed from the same magnetic material as that for the protuberance layer32. As a result, the above-described connection layers61can be formed in the same step as that of the above-described protuberance layer32and the back gap layer33and, therefore, speedup of the manufacturing process can be achieved.

As described above, the top surface of the above-described coil insulating layer36is provided as a flattened surface. Preferably, the above-described coil insulating layer36is formed from an inorganic insulating material, e.g., Al2O3or SiO2, in order to realize this.

The shape of the above-described laminate62will be described.FIG. 4is a perspective view showing an example of the above-described laminate62. InFIG. 4, the two-dimensional shape of each of the lower magnetic pole layer39, the gap layer40, the upper magnetic pole layer41, and the upper core layer42is composed of a front-end portion B and a rear-end portion C. The front-end portion B has a predetermined width dimension in the track-width direction (the X direction shown in the drawing) in the surface facing the recording medium, and extends in the height direction (the Y direction shown in the drawing) while keeping this width dimension. The rear-end portion C has a width in the track-width direction gradually increasing from both base ends B1and B1of the front-end portion B toward the height direction (the Y direction shown in the drawing). As described above, the track width Tw is regulated by the width dimension in the track-width direction (the X direction shown in the drawing) of the upper magnetic pole layer41in the surface facing the recording medium.

The above-described front-end portion B may take on a shape having a width dimension in the track-width direction gradually increasing from the surface facing the recording medium toward the height direction. In such a case, the rear-end portion C has a width dimension in the track-width direction further increasing from both base ends B1and B1of the above-described front-end portion B toward the height direction.

As shown inFIG. 4, a gap depth (Gd) is determined by the length in the height direction (the Y direction shown in the drawing) of the top surface40aof the above-described gap layer40from the surface facing the recording medium to the above-described Gd-determining layer38.

The materials for the lower magnetic pole layer39and the upper magnetic pole layer41will be described. Preferably, the above-described lower magnetic pole layer39and the upper magnetic pole layer41have saturation magnetic flux densities Bs higher than those of the upper core layer42, the lower core layer29, the protuberance layer32, and the back gap layer33. When the lower magnetic pole layer39and the upper magnetic pole layer41facing the gap layer40have high saturation magnetic flux densities, the recording magnetic field can be concentrated in the vicinity of the gap and, thereby, the packing density can be improved.

As shown inFIG. 1, the above-described lower magnetic pole layer39and the upper magnetic pole layer41further extend rearward of the Gd-determining layer38in the height direction (the Y direction shown in the drawing) and, therefore, a region exhibiting a high saturation magnetic flux density Bs can be provided at the location close to the first coil pieces55and the second coil pieces56. Consequently, the magnetic flux efficiency can be improved, and a thin film magnetic head having excellent recording characteristics can be prepared.

The gap layer40shown inFIG. 1is formed from a non-magnetic metal material, and is provided on the lower magnetic pole layer39by plating. Preferably, the above-described non-magnetic metal material is at least one selected from the group consisting of NiP, NiReP, NiPd, NiW, NiMo, NiRh, Au, Pt, Rh, Pd, Ru, and Cr. The gap layer40may have a single-layer structure or a multilayer structure.

The laminate62shown inFIG. 1has a four-layer structure composed of the lower magnetic pole layer39, the gap layer40, the upper magnetic pole layer41, and the upper core layer42. However, the laminate62may have a three-layer structure composed of the lower magnetic pole layer39, the gap layer40, and the upper magnetic pole layer41.

Each ofFIG. 5toFIG. 7shows a form different from that indicated by the partial front view of the thin film magnetic head shown inFIG. 2.FIG. 5toFIG. 7are partial front views showing a first coil piece, a second coil piece, and the like provided at the locations closest to a surface facing a recording medium while an MR head, a protuberance layer32, a protective layer60, and the like constituting the thin film magnetic head are not shown in the drawing.

In the thin film magnetic head shown inFIG. 5, in contrast to that shown inFIG. 2, an insulating layer63formed from an organic insulating material is provided over the top surface and the side surfaces of the above-described laminate62and, in contrast to that shown inFIG. 2, the insulating layer58formed from inorganic insulating material is not provided by sputtering on the top surface of the above-described laminate62. The other parts are the same as those shown inFIG. 2and, therefore, the top surfaces61aof the above-described connection layers61are flush with the top surface of the above-described protuberance layer32, the top surface of the back gap layer33, and the top surface of the coil insulating layer36in the thin film magnetic head shown inFIG. 5as well. As a result, the above-described laminate62can be provided on the above-described flattened surface, and the above-described laminate62can be formed into a predetermined shape.

Since the top surfaces61aof the above-described connection layers61are exposed at the same flattened surface as the above-described coil insulating layer36, the end portions in the track-width direction (the X direction shown in the drawing) of the above-described second coil pieces56can be electrically connected onto the above-described connection layers61with reliability and with ease.

In the thin film magnetic head shown inFIG. 6, the configuration of the layers under the reference surface A is the same as that shown inFIG. 2. That is, a plurality of first coil pieces55are provided in a space enclosed with a lower core layer29, a protuberance layer32, and a back gap layer33, and the top surfaces61aof connection layers (hereafter referred to as lower connection layers)61protruding from the end portions55ain the track-width direction (the X direction shown in the drawing) of the first coil pieces55are flush with the top surface of the above-described protuberance layer32, the top surface of the coil insulating layer36, and the top surface of the back gap layer33.

InFIG. 6, the above-described laminate62having a predetermined shape is highly precisely provided on the flattened surface of the top surface of the protuberance layer32, the top surface of the coil insulating layer36, and the top surface of the back gap layer33, and first lifting layers70electrically connected to the above-described lower connection layers61are provided in both sides of the above-described laminate62in the track-width direction (the X direction shown in the drawing).

For example, this first lifting layer70is formed by plating from the same material as that for the above-described laminate62simultaneously with the formation of the above-described laminate62. Consequently, the top surfaces70aof the above-described first lifting layers70are provided at the same height as that of the top surface62aof the above-described laminate62. Since the above-described laminate62has the four-layer structure composed of the lower magnetic pole layer39, the gap layer40, the upper magnetic pole layer41, and the upper core layer42, the above-described first lifting layer70also has the four-layer structure composed of them. In the present embodiment, since the above-described gap layer40is formed by plating from electrically conductive NiP, the first lifting layer70can be formed by plating from the same material as that for the above-described laminate62simultaneously with the formation of the above-described laminate62.

Electrically conductive second lifting layers71made of Cu or the like are provided on the above-described first lifting layers70, and the above-described second lifting layers71and the first lifting layers70are electrically connected. In the present embodiment, the area of the above-described first lifting layer70in a plane flush with the X-Y plane shown in the drawing is larger than the area of the above-described lower connection layer61in a plane flush with the X-Y plane shown in the drawing and the area of the second lifting layer71in a plane flush with the X-Y plane shown in the drawing. However, the relationship among the values of above-described areas of these layers is not specifically limited.

InFIG. 6, an upper connection layer72is composed of two layers of the above-described first lifting layer70and the second lifting layer71.

As shown inFIG. 6, the top surface and the side surfaces in the track-width direction of the above-described laminate62are covered with an insulating layer73formed from an inorganic insulating material, e.g., Al2O3, and this insulating layer73is also provided around the above-described upper connection layers72.

As shown inFIG. 6, the top surface73aof the above-described insulating layer73and the top surfaces72aof the above-described upper connection layers72are provided as the same flattened surface along the reference surface A.

A plurality of second coil pieces56parallel to each other are provided on the above-described flattened insulating layer73and upper connection layers72while being non-parallel to the above-described first coil pieces55and being arranged side by side in the height direction. The second coil pieces56are extended in the direction parallel to the track-width direction (the X direction shown in the drawing), or are extended in the track-width direction while being inclined toward the height direction (the Y direction shown in the drawing).

As shown inFIG. 6, the end portions56aand56bin the track-width direction (the X direction shown in the drawing) of the above-described second coil pieces56are electrically connected to the top surfaces72aof the above-described upper connection layers72and, thereby, a toroidal coil structure composed of the first coil pieces55, the lower connection layers61, the upper connection layers72, and the second coil pieces56is constructed.

In the form shown inFIG. 6, the above-described upper connection layers72electrically connected to the above-described lower connection layers61are provided, the top surface73aof the insulating layer73covering the above-described laminate62is provided as a flattened surface, and the top surfaces72aof the above-described upper connection layers72are exposed at surfaces flush with this flattened surface.

Consequently, the above-described second coil pieces56can be formed on the flattened insulating layer73and, thereby, the above-described second coil piece56can be formed into a predetermined shape. In addition, the above-described connection layers are lifted to the same level as that of the locations where the above-described second coil pieces56are provided, the top surfaces72aof the above-described upper-connection layers72are exposed at a reference surface F and, thereby, the end portions56aand56bin the track-width direction of the above-described second coil pieces56can be electrically connected to the above-described upper connection layers72with further reliability and with ease compared with that in the case where both sides in the track-width direction of the above-described second coil pieces56are bended downward and, thereby, the above-described second coil pieces56are connected to the top surfaces of the connection layers (lower connection layers)61exposed at the reference surface A, as shown inFIG. 2andFIG. 5. Furthermore, insulation between the above-described second coil pieces56and the laminate62becomes more desirable by adopting the form shown inFIG. 6.

FIG. 7shows a modified example of the coil structure shown inFIG. 6. InFIG. 7, an upper connection layer72electrically connected to the above-described lower connection layer61has a single-layer structure. The above-described upper connection layer72is formed from a conductive material, e.g., Cu. In thisFIG. 7as well, in a manner similar to that shown inFIG. 6, the top surfaces72aof the above-described upper connection layers72are provided as the same flattened surface as the top surface73aof the insulating layer73covering the top surface of the above-described laminate62, and the top surfaces72aof the above-described upper connection layers72are exposed at the above-described flattened surface. Consequently, the second coil piece56can be formed into a predetermined shape and, in addition, the end portions56aand56bin the track-width direction of the above-described second coil pieces56can be electrically connected to the above-described upper connection layers72with further reliability and with ease.

The structure of the above-described upper connection layer72is not limited to the laminated structure of two layers as shown inFIG. 6or a single-layer structure as shown inFIG. 7, and may be a laminated structure of at least three layers.

In the embodiments shown inFIG. 6andFIG. 7, both of the top surface of the insulating layer36and the top surfaces of the lower connection layers61under the laminate62are provided as the same flattened surface along the reference surface A. However, with respect to the configuration, the relationship between the locations of the top surface of the above-described insulating layer36and the top surfaces of the lower connection layers61may not be limited, while at least the top surface73aof the insulating layer73covering the above-described laminate62and the top surfaces72aof the above-described upper connection layers72are provided as the same flattened surface.

A method for manufacturing the thin film magnetic head shown inFIG. 1will be described below with reference to the manufacturing step diagrams shown inFIG. 8toFIG. 16. A method for forming each layer of the lower core layer29to the second coil pieces56shown inFIG. 1will be described. Each of the manufacturing step diagrams shown inFIG. 8toFIG. 16is a vertical sectional view (that is, a sectional view showing a cross section parallel to the X-Z plane shown in the drawing) of the thin film magnetic head at some midpoint in manufacture.

In the step shown inFIG. 8, the lower core layer29made of a NiFe-based alloy or the like is formed by plating, and a portion from the rear-end surface in the height side of the above-described lower core layer29toward the height direction (the Y direction shown in the drawing) and both sides in the track-width direction (the X direction shown in the drawing) of the above-described lower core layer29are covered with a non-magnetic insulating material layer31made of Al2O3or the like. Subsequently, the surface of the above-described lower core layer29and the surface of the non-magnetic insulating material layer31are polished by using a CMP technology or the like, so that a flattened surface is provided.

In the step shown inFIG. 9, the coil insulating substrate layer34made of Al2O3or the like is formed by sputtering or the like on the surface of the above-described lower core layer29and the surface of the non-magnetic insulating material layer31. The first coil pieces55are formed by patterning on the above-described coil insulating substrate layer34. The above-described first coil pieces55are formed by plating from a non-magnetic conductive material, e.g., Cu.

A plurality of first coil pieces55are provided parallel to each other. Each first coil piece55is extended parallel to the track-width direction (the X direction shown in the drawing) or is extended in the track-width direction (the X direction shown in the drawing) while being inclined toward the height direction (the Y direction shown in the drawing). Subsequently, the coil insulating substrate layer34is removed from the region where the protuberance layer32and the back gap layer33are to be provided in the following step.

In the step shown inFIG. 10, a resist layer75is applied to the above-described coil insulating substrate layer34, and hole portions75aand75bare formed in this resist layer75by an exposure phenomenon. The above-described hole portion75ais provided in the region from the surface facing the recording medium to the vicinity of the front-end portion of the above-described first coil piece55provided at the location closest to the surface facing the recording medium among the above-described first coil pieces55, and the above-described hole portion75bis provided in the vicinity of the base end portion of the above-described lower core layer29. The protuberance layer32is formed by plating on the above-described lower core layer29exposed at the hole portion75a, and in the same step, the back gap layer33is formed by plating on the base end portion of the above-described lower core layer29exposed at the hole portion75b. The coil insulating substrate layer34is not present between the above-described protuberance layer32and the lower core layer29and between the back gap layer33and the lower core layer29. Consequently, these layers are magnetically connected to each other.

FIG. 11is a partial vertical sectional view of the thin film magnetic head, showing a cross section different from that shown inFIG. 10.FIG. 11is the partial vertical sectional view showing, for example, a cross section parallel to the X-Z plane in the vicinity of the right end portion in the track-width direction (the X direction shown in the drawing) of the above-described first coil piece55.

The step shown inFIG. 11is performed simultaneously with the step shown inFIG. 10while a coil plating seed film remains. As shown inFIG. 11, each hole portion75creaching the end portion in the track-width direction of the above-described first coil piece55is provided by the exposure phenomenon in the above-described resist layer75, and the top surface of the end portion in the track-width direction of the above-described first coil piece55is exposed at the above-described hole portion75c.

The connection layers61are provided by plating in the hole portions75cshown inFIG. 11through the use of Cu, Au, Ni, Cu/Ni, or NiFe. Subsequently, the coil plating seed film is removed.

In this manner, the above-described protuberance layer32, the back gap layer33, and the connection layers61can be formed through the use of the coil plating seed film by the steps shown inFIG. 10andFIG. 11. Consequently, the speedup of the manufacturing process can be achieved, and the formation of the above-described connection layers61can be facilitated. The above-described connection layers61may be formed by another step before or after the above-described protuberance layer32and the back gap layer33are formed.

The resist layer75is removed. In the step shown inFIG. 12, the above-described first coil pieces55, the above-described protuberance layer32, and the back gap layer33are covered with the coil insulating layer36made of Al2O3or the like. The above-described coil insulating layer36is formed by sputtering or the like. At this time, as shown inFIG. 13, the connection layers61provided on the end portions in the track-width direction of the above-described first coil pieces55are also covered with the above-described coil insulating layer36.

The above-described coil insulating layer36, the protuberance layer32, the back gap layer33, and the connection layers61are cut up to a line D—D shown inFIG. 12andFIG. 13from the direction parallel to the X-Y plane by using a CMP technology or the like.FIG. 14shows the condition in which the cutting is completed.

InFIG. 14, the top surface of the protuberance layer32, the top surface of the coil insulating layer36, the top surface of the back gap layer33, and the top surfaces of the above-described connection layers61not shown in the drawing are provided as a flattened surface along the reference surface A. As shown inFIG. 14, the first coil pieces55are in the condition of being completely covered with the above-described coil insulating layer36. In order to appropriately perform the above-described polishing, the above-described coil insulating layer36must be formed from an inorganic insulating material, e.g., Al2O3. For example, in the case where the above-described coil insulating layer36is formed from an organic insulating material, appropriate cutting cannot be performed by even the above-described polishing because of stickiness of the above-described organic insulating material and, therefore, it is difficult to flatten.

In the step shown inFIG. 15, the Gd-determining layer38is formed in the location at a predetermined distance in the height direction (the Y direction shown in the drawing) from the surface facing the recording medium. The above-described Gd-determining layer38is formed from an inorganic insulating material or an organic insulating material.

In the step shown inFIG. 16, the plating seed film (not shown in the drawing) required for plating is formed from a NiFe alloy, a FeCo alloy, or the like. Subsequently, a resist layer65provided with a pattern65ahaving, for example, a two-dimensional shape composed of the front-end portion B and the rear-end portion C shown inFIG. 4is formed, and the lower magnetic pole layer39, the gap layer40, the upper magnetic pole layer41, and the upper core layer42are continuously formed by plating in that order from the bottom in this pattern65a.

The two-dimensional shape of each of the above-described lower magnetic pole layer39, the gap layer40, the upper magnetic pole layer41, and the upper core layer42is composed of the front-end portion B and the rear-end portion C. The front-end portion B has a slim shape from the surface facing the recording medium toward the height direction (the Y direction shown in the drawing), and the rear-end portion C has the width in the track-width direction (the X direction shown in the drawing) increasing from both base ends BI of the front-end portion B toward the height direction. At this time, the track width Tw is regulated by the width dimension in the track-width direction (the X direction shown in the drawing) of the above-described upper magnetic pole layer41in the above-described facing-surface. Subsequently, the above-described resist layer65is removed.

The step shown inFIG. 16has the effect that the laminate62composed of the above-described lower magnetic pole layer39, the gap layer40, the upper magnetic pole layer41, and the upper core layer42can be formed on the flattened coil insulating layer36, protuberance layer32, and back gap layer33. That is, the above-described laminate62can be highly precisely formed into a predetermined shape on the above-described coil insulating layer36, the protuberance layer32, and the back gap layer33and, thereby, the above-described track width Tw can have a predetermined dimension.

Following the completion of the step shown inFIG. 16, the insulating layers58and63shown inFIG. 2are formed, and hole portions are formed in the insulating layer63formed from an organic insulating material by the exposure phenomenon, so that the top surfaces61aof the above-described connection layers61are exposed at the above-described hole portions. Subsequently, the second coil pieces56are formed by patterning over the above-described insulating layers58and63and the top surfaces61aof the above-described connection layers61. The above-described second coil pieces56are formed by plating from a non-magnetic conductive material, for example, Cu. A plurality of second coil pieces56parallel to each other are provided while being non-parallel to the above-described first coil pieces55. Each of the above-described second coil pieces56is extended in the direction parallel to the track-width direction (the X direction shown in the drawing), or is extended in the track-width direction while being inclined toward the height direction (the Y direction shown in the drawing).

According to the above-described manufacturing method, the top surfaces of the coil insulating layer36, the protuberance layer32, the back gap layer33, and the connection layers61are provided as the same flattened surface along the reference surface A by using the CMP technology or the like in the steps shown inFIG. 12andFIG. 13. Consequently, the top surfaces61aof the above-described connection layers61are in the condition of being exposed at the above-described flattened surface and, thereby, the end portions56aand56bin the track-width direction (the X direction shown in the drawing) of the above-described second coil pieces56are reliably, easily connected to the top surfaces61aof the above-described connection layers61.

Each ofFIG. 17toFIG. 19is a diagram showing a step of a method for manufacturing the thin film magnetic head shown inFIG. 6, and is a partial front view wherein the protuberance layer32and the like are not shown in the drawing.

The manufacturing steps up to the reference surface A are as described above. In the step shown inFIG. 17, the laminate62is formed by plating on the top surface of the coil insulating layer36, the top surface of the protuberance layer32, and the top surface of the back gap layer33while each top surface is flattened, and the first lifting layers70are simultaneously formed by plating from the same material on the top surfaces61aof the connection layers61exposed at the above-described reference surface A. Although not shown inFIG. 17, hole portions for forming the above-described first lifting layers70are formed by the exposure phenomenon in the resist layer65provided in the step shown inFIG. 16, and the above-described first lifting layers70are formed by plating in the resulting hole portions.

The above-described resist layer65is removed, and another resist layer76is applied onto the above-described laminate62, the coil insulating layer36, and the first lifting layers70. Subsequently, hole portions76apenetrating up to the top surfaces of the above-described first lifting layers70are provided in the above-described resist layer76by the exposure phenomenon, and the second lifting layers71are formed by plating in the resulting hole portions.

The first lifting layer70may not be formed in the step shown inFIG. 17, hole portions penetrating up to the top surfaces61aof the above-described connection layers (lower connection layers)61may be provided in the above-described resist layer76in the step shown inFIG. 18, and a single layer of the upper connection layer72may be formed by plating in each of the resulting hole portions. In such a case, the partial front view of the completed thin film magnetic head is the same asFIG. 7.

At least the top surfaces of the above-described upper connection layers72must be provided at the location higher than the top surface of the above-described laminate62.

The resist layer76shown inFIG. 18is removed. In the step shown inFIG. 19, the top surface of the above-described laminate62, the top surface of the coil insulating layer36, and the top surfaces of the upper connection layers72are covered with the insulating layer73made of an inorganic insulating material, e.g., Al2O3, the above-described insulating layer73and the upper connection layers72are cut up to a line E—E shown in the drawing by using a CMP technology or the like, so that the top surface of the above-described insulating layer73and the top surfaces of the upper connection layers72are processed into the same flattened surface. The top surface of the above-described laminate62must not be exposed by this polishing step. In order to appropriately perform the above-described polishing, the above-described insulating layer73must be formed from an inorganic insulating material, e.g., Al2O3. For example, in the case where the above-described insulating layer73is formed from an organic insulating material, appropriate cutting cannot be performed by even the above-described polishing because of stickiness of the above-described organic insulating material and, therefore, it is difficult to flatten.

In the step shown inFIG. 19, the above-described laminate62becomes in the condition of being completely covered with the above-described insulating layer73and, in addition, the top surfaces72aof the above-described upper connection layers72are exposed at surfaces flush with the flattened surface of the above-described insulating layer73.

The above-described second coil pieces56are formed by patterning on the above-described insulating layer73and the top surfaces72aof the above-described upper connection layers72. The insulating layer73covering the above-described laminate62is provided as a flattened surface in the step shown inFIG. 19and, thereby, the above-described second coil pieces56provided thereon can be formed on the flattened surface. Consequently, the above-described second coil piece56can be formed into a predetermined shape. Furthermore, the top surfaces72aof the upper connection layers72are exposed at the same surface as the above-described insulating layer73and, thereby, the end portions in the track-width direction of the above-described second coil pieces56can be provided on the top surfaces72aof the above-described upper connection layers72without bending the end portions in the track-width direction of the above-described second coil pieces56, in contrast to the manner shown inFIG. 2andFIG. 5. Consequently, the end portions in the track-width direction of the above-described second coil pieces56can be electrically connected to the top surfaces72aof the above-described upper connection layers72with further reliability and with ease.

FIG. 20is a partial vertical sectional view showing the structure of a thin film magnetic head according to the fifth embodiment of the present invention. The thin film magnetic head shown inFIG. 20has substantially the same structure as that of the thin film magnetic head shown inFIG. 1. Therefore, constituents of the thin film magnetic head shown inFIG. 20similar to those of the thin film magnetic head shown inFIG. 1are indicated by the same reference numerals as inFIG. 1, and detailed explanations thereof will not be provided.

In the thin film magnetic head shown inFIG. 20, the top surfaces of first coil pieces455are flush with a reference surface A, and the top surface of a protuberance layer32, the top surfaces of the first coil pieces455, the top surface of a coil insulating layer36, and the top surface of a back gap layer33are a continuous flattened surface along the above-described reference surface A.

A Gd-determining layer438is provided from the location at a predetermined distance in the height direction (the Y direction shown in the drawing) from the surface facing the recording medium toward the height direction. The front end surface438aof the above-described Gd-determining layer438is located on the above-described protuberance layer32, as in the thin film magnetic head shown inFIG. 1, and the rear end surface438bof the above-described Gd-determining layer438is located on the above-described back gap layer33. Alternatively, the rear end surface438bof the above-described Gd-determining layer438may be located on the boundary portion33bbetween the top surface of the above-described back gap layer33and a front-end portion33a.

In the thin film magnetic head shown inFIG. 20, the above-described Gd-determining layer438is provided on the first coil pieces455, and this Gd-determining layer438is formed from an organic insulating material or an inorganic insulating material. Consequently, even if the top surfaces of the first coil pieces455are extended to the above-described reference surface A and, therefore, are in contact with the bottom surface of the Gd-determining layer438, the first coil pieces455can be insulated from the laminate62. Therefore, the cross-sectional area of the first coil pieces455can be increased, and the resistance can be reduced.

FIG. 21is a front view of the thin film magnetic head shown inFIG. 20, viewed from the side of the surface facing the recording medium. This front view is similar to the front view of the thin film magnetic head shown inFIG. 7. InFIG. 21, the above-described protuberance layer32is not shown in the drawing, but the first coil piece455located rearward of the above-described protuberance layer32is shown in the drawing.

In the present embodiment, the top surfaces of the first coil pieces455are located on the flattened surface along the above-described reference surface A while the flattened surface is flush with the top surface of the protuberance layer32, the top surface of the coil insulating layer36, and the top surface of the back gap layer33and, thereby, the first coil pieces455can be directly connected to the upper connection layers72. Therefore, the connection layers61for connecting the first coil pieces34to the upper connection layers72may become unnecessary and the number of connection portions is decreased in the thin film magnetic head shown inFIG. 7, so that the value of resistance of the total coil layer is decreased. Consequently, the amount of heat generation is decreased, the amount of thermal expansion and the amount of protrusion of the surface facing the recording medium of the thin film magnetic head can be decreased, and a magnetic head having a small amount of floating can be provided.

InFIG. 21, the shape of the upper connection layer72is similar to that of the thin film magnetic head shown inFIG. 7. However, the upper connection layer72may be similar to that of the thin film magnetic head shown inFIG. 6. The first coil pieces455may be directly connected to the second coil pieces56without provision of the upper connection layers72.

The coil layer of the present invention is not limited to that shown inFIG. 3in which a plurality of first coil pieces55are parallel to each other, and a plurality of second coil pieces56are also parallel to each other.

That is, in the present invention, it is essential only that the first coil pieces extending in the direction intersecting the laminate62are provided in the space enclosed with the lower core layer29, the protuberance layer32, and the back gap layer33, the second coil pieces are provided while crossing over the laminate62, end portions of the above-described first coil pieces adjacent to each other are connected via the second coil pieces and, thereby, the above-described coil layer wound in a toroidal shape is provided.

FIG. 22toFIG. 26are plan views showing the two-dimensional structures of first coil pieces and second coil pieces capable of being applied to the thin film magnetic head of the present invention.

FIG. 22simply shows a laminate62and a coil layer90of a thin film magnetic head. The thin film magnetic head shown inFIG. 22has substantially the same structure as that of the thin film magnetic head shown inFIG. 1except that only the coil layer has a different structure.

That is, the plurality of first coil pieces80constituting the coil layer90of the thin film magnetic head shown inFIG. 22are not parallel to each other. With respect to the plurality of second coil pieces81, the portions81boverlapping the laminate62are parallel to each other, but the distance in the height direction (the Y direction shown in the drawing) between portions in both sides in the track-width direction (the X direction shown in the drawing) of the laminate62increases with increasing proximity to the end portions81a.

InFIG. 22, the above-described first coil pieces80provided under the laminate62are indicated by dotted lines, and the above-described second coil pieces81provided above the laminate62are indicated by solid lines.

In a manner similar to that in the structure shown inFIG. 2toFIG. 4, electrically conductive lifting layers82are connected to the end portions81ain the track-width direction (the X direction shown in the drawing) of the above-described second coil pieces81, and the lifting layers82are electrically connected to the end portions of the above-described first coil pieces80. The end portions of the above-described first coil pieces80are provided at the locations overlapping the end portions81aof the above-described second coil pieces81, although not shown inFIG. 22. The lifting layer82has a structure similar to that of the upper connection layer72shown inFIG. 2, and is in the condition of being connected to the end portion of the above-described first coil piece80via a connection layer similar to the above-described connection layer61. The coil layer90shown inFIG. 22also has a toroidal structure wound around the laminate62. Reference numerals83and84denote lead layers for connecting both end portions of the coil layer90to electrode layers.

InFIG. 22, for example, the distance S1a between the end portion81aof the leftmost second coil piece81in the drawing and the end portion81aof the second coil piece81on the right side thereof is larger than a minimum distance L1a between the above-described second coil pieces in the region overlapping the above-described laminate62.

The distances S1b and S1c between the end portions81aof the second coil piece81which is the second from the left in the drawing and the end portions81aof the second coil piece81on the right side thereof are larger than a minimum distance L1b between the above-described second coil pieces in the region overlapping the above-described laminate62. The distance S1d between the end portion81aof the rightmost second coil piece81in the drawing and the end portion81aof the second coil piece81on the left side thereof is larger than a minimum distance L1c between these second coil pieces in the region overlapping the above-described laminate62.

In the above description, the distance between the end portion81aand another end portion81arefers to the distance between the center of the end portion81aand the center of the other end portion81a. The minimum distance between the above-described second coil pieces in the region overlapping the above-described laminate62refers to a minimum distance between straight lines dividing the above-described respective second coil pieces into equal parts in the width direction.

With respect to an inductive thin film magnetic head, preferably, the volume of a magnetic circuit for flowing a magnetic flux is reduced and, thereby, inductance is reduced. Consequently, the length in the height direction of the above-described laminate62must be decreased, and the distances L1a, L1b, and L1c between the above-described second coil pieces81in the region overlapping the above-described laminate62are also decreased. At this time, by increasing the distance between the end portion81aof the above-described second coil piece81and the end portion81aof another second coil piece81adjacent to each other in the height direction, as in the present invention, the end portions81aare easily formed, and the end portions of the above-described first coil pieces80and the end portions81aof the second coil pieces81can be easily, reliably connected.

The above-described plurality of second coil pieces81include portions81bparallel to each other in the region overlapping the above-described laminate62, and the portions81bextend in the track-width direction shown in the drawing. Consequently, the magnetic field induced from the above-described coil layer90to the above-described laminate62is stabilized.

In the structure of the coil layer90shown inFIG. 22, the above-described plurality of second coil pieces81are parallel to each other all over the region overlapping the above-described laminate62. However, even the above-described plurality of second coil pieces81including portions81bparallel to each other in a part of the region overlapping the above-described laminate62, as shown inFIG. 23, can exert the effect of stabilizing the magnetic field induced from the above-described coil layer90to the above-described laminate62.

In the present invention, it is only essential that, with respect to at least one pair of the above-described second coil pieces81, the distance between the end portion81aand another end portion81aadjacent to each other in the height direction is larger than a minimum distance between the above-described second coil pieces81in the region overlapping the above-described laminate62.

For example, the structure of the coil layer shown inFIG. 24is also included within the scope of the present invention. InFIG. 24, only the distance S1d between the end portion81aof the rightmost second coil piece81in the drawing and the end portion81aof the second coil piece81on the left side thereof is larger than a minimum distance L1c between the above-described second coil pieces81in the region overlapping the above-described laminate62. However, with respect to each of other combinations of the above-described second coil pieces81, the distance between the end portion81aand another end portion81aadjacent to each other in the height direction is equal to the minimum distance between the above-described second coil pieces81in the region overlapping the above-described laminate62.

In the description with respect toFIG. 22toFIG. 24, the distance between the above-described second coil pieces81is increased from the region overlapping the above-described laminate62toward the end portions81a. A similar configuration can also be applied to the above-described first coil pieces80.

FIG. 25shows a coil layer91having a configuration in which the distance between the above-described first coil pieces80is also increased from the region overlapping the above-described laminate62toward the end portions of the above-described first coil pieces80.

The structure of second coil pieces81of the coil layer91shown inFIG. 25is the same as the structure of the second coil pieces81of the coil layer90shown inFIG. 23.FIG. 25shows the end portions80aof the first coil pieces80which are not shown inFIG. 23, but the end portions81aof the second coil pieces81are not shown in the drawing.

InFIG. 25, for example, the distances S2a and S2b between the end portion80aof the leftmost first coil piece80in the drawing and the end portion80aof the first coil piece80on the right side thereof (center) are larger than a minimum distance L2a between the above-described first coil pieces in the region overlapping the above-described laminate62.

The distances S2c and S2d between the end portion80aof the first coil piece80which is the second from the left (center) in the drawing and the end portion80aof the first coil piece80on the right side thereof (rightmost) are larger than a minimum distance L2b between the above-described first coil pieces in the region overlapping the above-described laminate62.

In the above description as well, the distance between the end portion80aand another end portion80arefers to the distance between the center of the end portion80aand the center of the other end portion80a. The minimum distance between the above-described first coil pieces in the region overlapping the above-described laminate62refers to a minimum distance between straight lines dividing the above-described respective first coil pieces into equal parts in the width direction.

The above-described plurality of first coil pieces80include portions80bparallel to each other in the region overlapping the above-described laminate62, and the portions80bextend in the track-width direction shown in the drawing. Consequently, the magnetic field induced from the above-described coil layer91to the above-described laminate62is stabilized.

The structure of the first coil pieces80may be different from that shown inFIG. 25. For example, the first coil pieces80may have a shape similar to the structure of the second coil pieces81shown inFIG. 22orFIG. 24.

A coil layer in which only the first coil pieces80have the structure of the present invention, that is, the distance between at least one combination of the above-described first coil pieces80is increased from the region overlapping the above-described laminate62toward the end portions of the above-described first coil pieces80, is included within the scope of the present invention.

The portions parallel to each other may not be provided in the region overlapping the above-described laminate62, as that in a coil layer92shown inFIG. 26.

FIG. 27is a partial vertical sectional view showing the structure of a thin film magnetic head according to the sixth embodiment of the present invention.FIG. 28is a partial front view of the thin film magnetic head shown inFIG. 27wherein an MR head, an insulating layer536, a protective layer564, and the like are not shown in the drawing, and a structure composed of a magnetic pole end layer, a first coil piece and a second coil piece provided at the locations closest to a surface facing a recording medium, and each layer facing these layers in the film thickness direction is viewed from the side of the surface facing the recording medium.

A playback head (may be referred to as an MR head) from the above-described lower shield layer22to the above-described upper shield layer27is the same as that in the thin film magnetic head according to any one of the first embodiment to the fifth embodiment.

As shown inFIG. 27, a separation layer28formed from Al2O3or the like is provided on the above-described upper shield layer27. The above-described upper shield layer27and the separation layer28may not be provided, and a following lower core layer529may be provided on the above-described upper gap layer26. In such a case, the above-described lower core layer529doubles as the upper shield layer.

InFIG. 27, the lower core layer529is provided on the above-described separation layer28. The above-described lower core layer529is formed from a magnetic material, e.g., a NiFe-based alloy. The above-described lower core layer529has a predetermined length dimension in the height direction (the Y direction shown in the drawing) from the surface facing the recording medium. A non-magnetic insulating material layer31is provided at the rear in the height direction of the rear end surface529aof the above-described lower core layer529and in both sides of the above-described lower core layer529in the track-width direction (the X direction shown in the drawing). As shown inFIG. 27, the surface of each of the above-described lower core layer529and the non-magnetic insulating material layer31is a continuous flattened surface.

As shown inFIG. 27, a magnetic pole end layer (protuberance layer)548having a predetermined length dimension rearward in the height direction from the surface facing the recording medium is provided on the lower core layer529. The magnetic pole end layer548has a width dimension in the track-width direction (the X direction shown in the drawing) of a track width Tw. The track width Tw is, for example, 0.5 μm or less.

In the embodiment shown inFIG. 28, the magnetic pole end layer548is configured to have a three-layer laminated structure composed of a lower magnetic pole layer549, a gap layer550, and an upper magnetic pole layer551. The magnetic pole layers549and551and the gap layer550will be described below.

The lower magnetic pole layer549for serving as a lowermost layer of the magnetic pole end layer548is provided by plating on the lower core layer529. The lower magnetic pole layer549is formed from a magnetic material, and is magnetically connected to the lower core layer529. The lower magnetic pole layer549may be formed from the same material as that for the lower core layer529or from a different material. The lower magnetic pole layer549may be composed of a single layer film or a multilayer film.

A non-magnetic gap layer550is laminated on the lower magnetic pole layer549.

Preferably, the gap layer550is formed from a non-magnetic metal material, and is provided on the lower magnetic pole layer549by plating. Preferably, the non-magnetic metal material is at least one selected from the group consisting of NiP, NiReP, NiPd, NiW, NiMo, NiRh, NiRe, Au, Pt, Rh, Pd, Ru, and Cr. The gap layer550may be composed of a single-layer film or a multilayer film.

The upper magnetic pole layer551magnetically connected to the upper core layer560described below is provided by plating on the gap layer550. In the present embodiment, the upper magnetic pole layer551has a laminated structure composed of a lower layer551aand an upper layer551b. The lower layer551aand the upper layer551bare formed from magnetic materials, and the saturation magnetic flux density of the lower layer551ais larger than the saturation magnetic flux density of the upper layer551b.

When the gap layer550is formed from a non-magnetic metal material, as described above, the lower magnetic pole layer549, the gap layer550, and the upper magnetic pole layer551can be continuously formed by plating.

A back gap layer533is provided on the above-described lower core layer529while being located at a predetermined distance in the height direction (the Y direction shown in the drawing) from the rear-end surface548ain the height direction of the above-described magnetic pole end layer548.

The back gap layer533is formed from a magnetic material. The back gap layer533may be formed from the same material as that for the above-described lower core layer529, or be formed from a different material. The back gap layer533may be a single layer, or may have a multilayer laminated structure. The back gap layer533is magnetically connected to the above-described lower core layer529.

A coil insulating substrate layer534is provided between the magnetic pole end layer548and the back gap layer533on the lower core layer529, and a plurality of first coil pieces555parallel to each other are provided on the above-described coil insulating substrate layer534while the first coil pieces555are extended parallel to the track-width direction (the X direction shown in the drawing) and are arranged side by side in the height direction. Each of the first coil pieces555may be extended in the track-width direction (the X direction shown in the drawing) while being inclined toward the height direction.

The above-described first coil pieces555are covered with a coil insulating layer536formed from an inorganic insulating material, e.g., Al2O3. As shown inFIG. 27, the top surface of the above-described magnetic pole end layer548, the top surface of the coil insulating layer536, and the top surface of the back gap layer533are provided as a continuous flattened surface along a reference surface A shown inFIG. 27.

As shown inFIG. 28, electrically conductive connection layers561are provided as protrusions on the end portions555ain the track-width direction (the X direction shown in the drawing) of the above-described first coil pieces555. The two-dimensional shape (that is, the shape of a surface cut from the direction parallel to the X-Y plane) of the above-described connection layer561can be selected from various shapes, e.g., an ellipse, a circle, a square, a rectangle, and a rhombus. Preferably, the above-described connection layer561is formed from the same material as that for the back gap layer533from the viewpoint of the manufacturing process. However, the material may be different from that for the back gap layer533. The above-described connection layer561may have a single-layer structure or a multilayer laminated structure. The above-described connection layers561are in the condition of being electrically connected to the end portions555aof the above-described first coil pieces555. The term “electrically connected” refers to a condition in which there is electrical continuity between two layers regardless of direct connection or indirect connection. Hereafter the same holds true.

As shown inFIG. 28, the top surfaces561aof the connection layers561provided on the end portions555ain the track-width direction (the X direction shown in the drawing) of each first coil piece555are flush with the above-described reference surface A. That is, with respect to the thin film magnetic head shown inFIG. 27, all of the top surface of the above-described magnetic pole end layer548, the top surface of the coil insulating layer536, the top surface of the back gap layer533, and the top surfaces561aof the connection layers561are provided as the same flattened surface.

As shown inFIG. 27, a Gd-determining layer538is provided from the location at a predetermined distance in the height direction (the Y direction shown in the drawing) from the above-described surface facing the recording medium toward the height direction on the lower core layer529. As shown inFIG. 27, the rear-end portion of the upper magnetic pole layer551is provided on the Gd-determining layer538. A gap depth (Gd) is determined by the length in the height direction (the Y direction shown in the drawing) of the above-described gap layer550from the surface facing the recording medium to the above-described Gd-determining layer538.

An upper core layer (magnetic layer)560is provided by plating on the above-described upper magnetic pole layer551and the back gap layer533. The above-described upper core layer560connects the height side of the above-described lower core layer529and the above-described magnetic pole end layer548via the back gap layer533, and the upper core layer560corresponds the magnetic layer of the present invention.

The upper magnetic pole layer551and the upper core layer560may be formed from the same material. However, preferably, these are formed from different materials. In particular, it is more preferable that the upper core layer560has a saturation magnetic flux density lower than that of the upper layer551bof the above-described upper magnetic pole layer551. The saturation magnetic flux density of the upper core layer560is, for example, 1.4 T to 1.9 T, the saturation magnetic flux densities of the lower layer and the upper layer of the above-described upper magnetic pole layer551are, for example, 1.9 T to 2.4 T and 1.4 T to 1.9 T, respectively.

When the saturation magnetic flux density of the above-described upper core layer560is lower than the saturation magnetic flux density of the above-described upper magnetic pole layer551, magnetic recording due to a leak magnetic field from the upper core layer560can easily be prevented.

As shown inFIG. 27andFIG. 28, an insulating layer558formed from an insulating material, e.g., Al2O3, is provided on the above-described upper core layer560. Preferably, the above-described insulating layer558is formed from an inorganic insulating material. This insulating layer558is also provided on the coil insulating layer536extending in both sides of the above-described upper core layer560in the track-width direction (the X direction shown in the drawing). As shown inFIG. 28, insulating layers563formed from an organic insulating material, e.g., a resist, are provided over both end portions in the track-width direction (the X direction shown in the drawing) of the above-described insulating layer558and both sides in the track-width direction of the above-described upper core layer560.

The insulating layer558formed from the inorganic insulating material is provided by a sputtering method or the like. Since the above-described insulating layer558can have a film thickness smaller than that of the insulating layer563formed from the organic insulating material, the upper core layer560and second coil pieces556described below can be brought close to each other, and the magnetization efficiency can be increased. In addition, insulation between the above-described upper core layer560and the second coil pieces556can be excellently maintained in both sides of the above-described upper core layer560in the track-width direction.

As shown inFIG. 27andFIG. 28, a plurality of second coil pieces556parallel to each other are provided on the above-described insulating layers558and563while being arranged side by side in the height direction. The second coil pieces556are extended in the track-width direction (the X direction shown in the drawing) while being inclined toward the height direction (the Y direction shown in the drawing). Each of the second coil pieces556may be extended in the direction parallel to the track-width direction (the X direction shown in the drawing).

The above-described first coil pieces555and the second coil pieces556are non-parallel to each other, and, as shown inFIG. 28, the left end portion555ain the track-width direction of the first coil piece555and the left end portion556ain the track-width direction of the second coil piece556face each other in the film thickness direction (the Z direction shown in the drawing) of the magnetic layer560, and the left end portion555aand the left end portion556aare electrically connected to each other via the connection layer561. The right connection layer561indicated by a dotted line shown inFIG. 28electrically connects the right end portion of the first coil piece555located at the back (the Y direction shown in the drawing) of the first coil piece555visible in the drawing and the right end portion556bof the second coil piece556visible in the drawing.

As described above, in the thin film magnetic head shown inFIG. 27andFIG. 28, the end portion in the track-width direction of the first coil piece555and the end portion in the track-width direction of the second coil piece556facing one above the other in the film thickness direction of the above-described magnetic layer560are electrically connected to each other via the connection layer561and, thereby, a toroidal coil structure557is provided.

A layer denoted by reference numeral564shown inFIG. 27is a protective layer formed from Al2O3or the like, and a layer denoted by reference numeral559shown inFIG. 27is a lead layer. The above-described lead layer559is integrally formed with the second coil piece556located at the front end in the height direction.

When a recording current is applied to the coil layer557, a recording magnetic field is induced in the lower core layer529and the upper core layer560, a leakage magnetic field is generated between the lower magnetic pole layer549and the upper magnetic pole layer551facing each other with the gap layer550, and a magnetic signal is recorded on the recording medium, e.g., hard disk, due to this leakage magnetic field.

In the thin film magnetic head shown inFIG. 27, the plurality of first coil pieces555are provided in the space enclosed with the above-described lower core layer529, the magnetic pole end layer548, and the back gap layer533. The space in which the above-described first coil pieces555can be provided is appropriately formed by protruding the magnetic pole end layer548and the back gap layer533on the above-described lower core layer529. In particular, since the above-described magnetic pole end layer548and the back gap layer533are provided by plating, the above-described magnetic pole end layer548and the back gap layer533having large thicknesses can be formed. Consequently, the space enclosed with the above-described lower core layer529, the magnetic pole end layer548, and the back gap layer533is allowed to become wide, and the above-described first coil pieces555having predetermined film thicknesses are easily provided.

The connection layers561are protruded from the end portions555ain the track-width direction of each first coil piece555. The top surfaces of the connection layers561are flush with the top surface of the above-described magnetic pole end layer548, the top surface of the back gap layer533, and the top surface of the coil insulating layer536and, therefore, the top surfaces of the connection layers561are in the condition of being exposed at the above-described flattened surface.

Consequently, in the thin film magnetic head shown inFIG. 27, the above-described upper core layer560provided on the above-described magnetic pole end layer548, the coil insulating layer536, and the back gap layer533can be formed on the above-described flattened surface, and the above-described upper core layer560can be formed into a predetermined shape. Therefore, the resulting upper core layer560can have a predetermined dimension with high precision.

In the thin film magnetic head shown inFIG. 27, since the top surfaces561aof the above-described connection layers561are exposed at the same flattened surface as the above-described coil insulating layer536, the end portions in the track-width direction (the X direction shown in the drawing) of the above-described second coil pieces556can be electrically connected onto the above-described connection layers561with reliability and with ease. Consequently, poor electrical contact between the above-described first coil pieces555and the second coil pieces556can be prevented.

Since all of the top surface of the coil insulating layer536, top surface of the magnetic pole end layer548, the top surface of the back gap layer533, and the top surfaces of the connection layers561are provided as the same flattened surface, the slimming of the whole thin film magnetic head can be facilitated.

Since the above-described upper core layer560having a linear shape parallel to the layer surface connects between the above-described magnetic pole end layer548and the back gap layer533and, thereby, the magnetic path is provided, reduction in the magnetic path length can be realized. Since the magnetic path length can be reduced, the speed of magnetic field reversal can be increased, and a thin film magnetic head having excellent high-frequency characteristics can be provided.

The above-described first coil piece555and the second coil piece556are formed from Cu, Au, or the like having excellent electrical conductivity. The above-described connection layer561may not be formed from the same material as that for the above-described first coil piece555and the second coil piece556, and may be formed from a magnetic material or the like, as long as the material has electrical conductivity. Preferably, the above-described connection layer561is formed from the same magnetic material as that for the magnetic pole end layer548. As a result, the above-described connection layers561can be formed in the same step as that of the above-described magnetic pole end layer548and the back gap layer533and, therefore, speedup of the manufacturing process can be achieved.

As described above, the top surface of the above-described coil insulating layer536is provided as a flattened surface. In order to realize this, preferably, the above-described coil insulating layer536is formed from an inorganic insulating material, e.g., Al2O3or SiO2.

The two-dimensional shape of the above-described upper core layer560is similar to that of the upper core layer42shown inFIG. 4.

In the present embodiment, the material for the upper core layer560is differentiated from that for the upper magnetic pole layer551of the magnetic pole end layer548. Consequently, only the upper magnetic pole layer551can be formed from a material having a high saturation magnetic flux density, and the upper core layer560can be formed from a material having a saturation magnetic flux density lower than that of the upper magnetic pole layer551. Since the upper magnetic pole layer551and the lower magnetic pole layer549having high saturation magnetic flux densities are not formed at the rear of the Gd-determining layer538, the magnetic flux density can be appropriately controlled, leakage of the magnetic flux from both sides of the magnetic pole end layer548is reduced, and an S/N ratio of the magnetic head is improved.

Leakage of the magnetic flux from the upper core layer560can be further reduced by moving the front-end portion560aof the upper core layer560from the surface facing the recording medium backward in the height direction.

In the present embodiment, the value of resistance can be reduced by allowing the film thickness t1of the second coil piece556on the upper core layer560to be larger than the film thickness t2of the first coil piece555, and allowing the length dimension W2of the above-described second coil piece in a first direction orthogonal to the direction of a current flow to be larger than the length dimension W1of the above-described first coil piece in the first direction. That is, the heat generation of the above-described coil layer557can be reduced, and protrusion of the magnetic pole end layer548and the vicinity thereof toward the recording medium side can be reduced.

In the magnetic head shown inFIG. 27andFIG. 28, since the upper core layer560having a flat shape connects between the magnetic pole end layer548and the back gap layer533and, thereby, the magnetic path is provided, the magnetic path length can be reduced compared with that in the magnetic head including a protuberant upper core layer. When the upper core layer560has the flat shape, Joule heat generated from the coil layer557can be efficiently dissipated to the outside of the magnetic head.

The coil layer557has a toroidal coil structure wound around the upper core layer560.

Consequently, even when the number of turns of the coil layer557constituting the magnetic head is decreased, a predetermined recording time can be maintained. Since the number of turns can be decreased, the coil resistance can be reduced and, thereby, heat generation of the magnetic head can be reduced even when the magnet head is driven.

The reduction of the heat generation of the magnetic head leads to reduction of problems, for example, that the magnetic pole end layer548and the vicinity thereof protrude from the surface F facing the recording medium.

The thermal expansion coefficient of the magnetic head can be reduced by the use of an inorganic insulating material for the coil insulating layer536covering the coil layer557.

FIG. 29is a partial front view showing a thin film magnetic head according to the seventh embodiment of the present invention. An MR head, a protective layer561, and the like constituting the thin film magnetic head are not shown in the drawing, and a structure composed of a first coil piece, a second coil piece, a magnetic pole end layer, and each of layers facing these layers in the film thickness direction is shown, wherein the structure is provided at the location closest to the side of a surface facing a recording medium.

In the thin film magnetic head shown inFIG. 29, the configuration of the layers under the reference surface A is the same as that shown inFIG. 28. That is, a plurality of first coil pieces555are provided in the space enclosed with a lower core layer529, a magnetic pole end layer548, and a back gap layer533. The top surfaces561aof connection layers561protruding from the end portions555ain the track-width direction (the X direction shown in the drawing) of the first coil pieces555are flush with the top surface of the above-described magnetic pole end layer548, the top surface of the coil insulating layer536, and the top surface of the back gap layer533.

InFIG. 29, the above-described upper core layer560having a predetermined shape with high precision is provided on the flattened surface of the top surface of the magnetic pole end layer548, the top surface of the coil insulating layer536, and the top surface of the back gap layer533, and lifting layers572electrically connected to the above-described lower connection layers561are provided in both sides in the track-width direction (the X direction shown in the drawing) of the above-described upper core layer560.

As shown inFIG. 29, the above-described lifting layer572has a configuration in which two lifting layers are laminated with a step height. A lower lifting layer570of the above-described lifting layer572is formed by plating from the material constituting the above-described upper core layer560. Alternatively, the above-described lower lifting layer570may have a laminated structure in which at least one layer of protective film selected from the group consisting of Ni, CuNi, and NiP is provided on at least one layer selected from the group consisting of Cu, FeNi, Ni, Au, FeCo, FeCoRh, and FeCoNi.

An upper lifting layer571(hereafter referred to as a lifting-adjusting layer) laminated on the above-described lower lifting layer570with a step height has a function of adjusting the total height of the above-described lifting layer572. As shown inFIG. 29, the lifting-adjusting layer571is provided on the lower lifting layer570and, thereby, the top surface572aof the above-described lifting layer572is allowed to become higher than the top surface562aof the above-described upper core layer560.

The above-described lifting-adjusting layer571has electrical conductivity, and is formed from a material which can be applied by plating. Preferably, the above-described lifting-adjusting layer571is at least one layer selected from the group consisting of Cu, FeNi, Ni, Au, FeCo, FeCoRh, and FeCoNi. Alternatively, the above-described lifting-adjusting layer571may have a structure in which at least one layer of protective film selected from the group consisting of Ni, CuNi, and NiP is provided on a primary layer containing Cu, Co, or Ni.

The bottom surface of the above-described lower lifting layer570and the top surface of the above-described connection layer561are in the condition of being electrically connected to each other, and the top surface570aof the lifting layer570and the bottom surface of the lifting-adjusting layer571are also electrically connected to each other.

The advantage of the two-stage structure of the lifting layer572, as shown inFIG. 29, is that the top surface572aof the above-described lifting layer572is easily allowed to become higher than the top surface560aof the above-described upper core layer560. After the above-described lower lifting layer570is provided, the above-described lifting-adjusting layer571is provided by plating on the above-described lower lifting layer570through a different step.

Since the top surface572aof the above-described lifting layer572is allowed to become higher than the top surface560aof the above-described upper core layer560, the top surface573aof the insulating layer573(preferably, formed from an inorganic insulating material) covering the top surface and the side surfaces of the above-described upper core layer560can be provided as a flattened surface parallel to the X-Y plane shown in the drawing and, thereby, the above-described second coil pieces556can be provided on the above-described flattened surface. As a result, the above-described second coil pieces can highly precisely formed by patterning, and the end portions556aand556bof the above-described second coil piece556can be electrically connected with reliability and with ease to the top surfaces572aof the above-described lifting layer572exposed at the above-described flattened surface. Since the lifting layer572higher than the top surface560aof the above-described upper core layer560is provided, insulation between the above-described second coil pieces556and the above-described upper core layer560can be further improved.

A structure shown inFIG. 30, instead of the structure shown inFIG. 29, allows the top surface572aof the above-described lifting layer572to become higher than the top surface560aof the above-described upper core layer560.

In the structure of the thin film magnetic head shown inFIG. 30, lifting layers572are provided on the coil insulating layer536in both sides of the above-described upper core layer560in the track-width direction (the X direction shown in the drawing), and the area of the lifting layer572in the film surface direction (a direction parallel to the X-Y plane shown in the drawing) is constant from the bottom surface to the top surface572a. The lifting layer572has a single-layer structure or a multilayer structure of an electrically conductive material, and the top surface572aof the above-described lifting layer572is higher than the top surface560aof the above-described upper core layer560, as shown inFIG. 30. Preferably, the lifting layer572shown inFIG. 30is provided by plating, and is at least one layer selected from the group consisting of Cu, FeNi, Ni, Au, FeCo, FeCoRh, and FeCoNi. More preferably, the above-described lifting layer572has a laminated structure in which at least one layer of protective film selected from the group consisting of Ni, CuNi, and NiP is provided on at least one primary layer selected from the group consisting of Cu, FeNi, Ni, Au, FeCo, FeCoRh, and FeCoNi.

Consequently, in the thin film magnetic head shown inFIG. 30as well, the above-described second coil pieces556can be provided on the above-described flattened surface. As a result, the above-described second coil pieces556can highly precisely formed by patterning, and the end portions556aand556bof the above-described second coil piece556can be electrically connected with reliability and with ease to the top surfaces572aof the above-described lifting layers572exposed at the above-described flattened surface. Since the lifting layer572higher than the top surface560aof the above-described upper core layer560is provided, insulation between the above-described second coil pieces556and the above-described upper core layer560can be further improved.

Method for manufacturing the thin film magnetic heads shown inFIG. 27toFIG. 30are similar to the methods for manufacturing the thin film magnetic heads shown inFIG. 8toFIG. 19. The magnetic pole end layer548is formed by plating instead of the protuberance layer32, and the upper core layer560is formed instead of the laminate62.

Methods for manufacturing the above-described lifting layers572shown inFIG. 29andFIG. 30are the same as the methods for manufacturing the above-described lifting layers72shown inFIG. 6andFIG. 7, respectively.

The thin film magnetic head according to the present invention described above in detail is built in a magnetic head device mounted on, for example, a hard disk device. The above-described thin film magnetic head is built in either floating magnetic head or contact magnetic head. The above-described thin film magnetic head can be used for a magnetic sensor and the like in addition to the hard disk device.