JP2005116101A - Magnetic head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic head which reduces both size of an upper core layer, and value of resistance and heat release by enlarging a cross section of a toroidal coil. <P>SOLUTION: A second coil segment 41 formed on top of the upper core layer 39 via an insulation layer 40 is also formed on top of a back gap layer 34. Thus, the value of resistance and the heat release and reduced by enlarging the size of width in height direction for the second coil segment 41 and enlarging the cross section, and the size of the upper core layer 39 and the lower core layer 29 is made equal to, or smaller than, the conventional one at the same time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a magnetic head for recording used in, for example, a floating magnetic head, and more particularly to a magnetic head excellent in heat dissipation by optimizing the shape of a toroidal coil layer.

  Thin-film magnetic heads for recording (inductive heads) having a core layer and a coil layer have been downsized with the recent increase in recording density, and the coil layer is wound in a very small space. It has to be formed. For this reason, a structure in which the core layer is wound around in a toroidal shape around the core layer is considered to be the mainstream in future inductive heads.

  For example, the following publicly known documents disclose the configuration of a coil layer wound around a core layer constituting an inductive head in a toroidal shape. By using such a toroidal coil layer, it was expected that the three-dimensional space around the core layer could be effectively utilized, thereby enabling the downsizing of the inductive head and improving the magnetization efficiency. .

  However, in the downsized inductive head using the toroidal-shaped coil layer, the following problems are particularly noticeable. In other words, Joule heat generated by the recording current flowing through the coil layer and heat due to eddy current generated in the core are not easily released from the inductive head, and as a result, the temperature inside the inductive head becomes very high. It has occurred.

  When the temperature inside the inductive head increases, the inductive head is formed due to the difference in thermal expansion coefficient between the coil layer or core layer formed of a metal material and the insulating material covering the periphery thereof. The portion that is present is more likely to protrude from the surface facing the recording medium as compared to other portions.

  In particular, in a thin film magnetic head capable of increasing the recording density, the frequency of the recording current applied to the toroidal coil is high, so the temperature inside the inductive head increases rapidly, and the amount of protrusion from the surface facing the recording medium increases. It gets bigger. When the inductive head protrudes from the surface facing the recording medium in this way, the frequency with which the inductive head collides with the recording medium increases, and the recording medium is damaged or the inductive head is easily damaged.

  10 and 11 show a conventional toroidal coil type magnetic head as disclosed in Patent Document 1. FIG. 10 is a cross-sectional view of the magnetic head, and FIG. 11 is a plan view of FIG. 10 as viewed from above.

  As shown in FIG. 10, a plurality of first coil pieces 3 constituting a toroidal coil are formed on the lower core layer 1 made of a magnetic material via an insulating layer 2. Is covered with an insulating layer 4. An upper core layer 5 made of a magnetic material is formed on the insulating layer 4. On the side of the lower core layer 1 facing the recording medium F, an upper magnetic pole layer 6 made of a magnetic material, a gap layer 7 made of a nonmagnetic material, and a magnetic pole portion 9 made of a lower magnetic pole layer 8 made of a magnetic material are formed. The track width dimension of the magnetic head is defined by the width dimension of the magnetic pole portion 9 in the X direction (track width direction).

  The upper magnetic pole layer 8 is connected to the upper core layer 5. The lower core layer 1 and the upper core layer 5 are connected via a back gap layer 10 made of a magnetic material at the rear in the Y direction in the figure.

  A plurality of second coil pieces 12 constituting a toroidal coil are formed on the upper core layer 5 via an insulating layer 11.

The upper part which has the 1st coil piece 3 and the 2nd coil piece 12 by electrically connecting the edge part in the track width direction of the 1st coil piece 3 and the edge part in the track width direction of the 2nd coil piece 12 A toroidal coil wound around the core layer 5 is formed.
JP 2001-76313 A JP-A-5-101337

  Here, as shown in FIGS. 10 and 11, in the conventional toroidal coil type magnetic head, the second coil piece 12 is closer to the surface F facing the recording medium than the front end face 10 a of the back gap layer 10. It was formed and was not formed on the back gap layer 10.

  Therefore, in order to form the toroidal coil excellent in heat dissipation, making the shape of the 2nd coil piece 12 suitable was restrict | limited.

  A magnetic head in which a lead layer 13 for supplying a recording current to the second coil piece 12 is formed on the back gap layer 10 as shown in FIG. .

  However, the lead layer 13 does not extend on the back gap layer 10 in a direction parallel to the extending direction (X direction in the drawing) of the second coil piece 12. That is, the magnetic flux generated from the lead layer 13 does not circulate in the same direction as the magnetic flux generated from the second coil piece, and does not function as the second coil piece that applies the magnetic flux to the upper core layer.

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a magnetic head that optimizes the shape of the toroidal coil layer and is excellent in heat dissipation.

A magnetic head according to the present invention includes a lower core layer formed extending in a first direction from a surface facing the recording medium, and a back gap layer made of a magnetic material at a predetermined distance from the lower core layer. A magnetic layer directly or indirectly connected to the lower core layer on the height side via,
The ends in the track width direction of the plurality of first coil pieces formed on the lower side of the magnetic layer and the ends in the track width direction of the plurality of second coil pieces formed on the upper side of the magnetic layer are electrically connected. Connected to each other, and a toroidal coil layer formed around the magnetic layer having the first coil piece and the second coil piece is formed,
A second coil piece similar in shape to the other second coil pieces is formed on the back gap layer.

  In the present invention, the second coil piece is not formed on the upper core layer only within the range of the surface facing the recording medium from the front end surface of the back gap layer. It is also formed on the top.

  Therefore, even if the size of the upper core layer and the lower core layer is the same as or smaller than the conventional size, the cross-sectional area of the second coil piece can be maintained large, so that the DC resistance value of the second coil piece can be reduced.

  As a result, the magnetic head of the present invention reduces Joule heat generated by the recording current flowing through the coil layer, can suppress the temperature rise inside the magnetic head, and even when the recording frequency is high, the magnetic head made of a metal material Protrusion of the front end portion from the surface facing the recording medium can be suppressed.

  That is, the frequency with which the magnetic head collides with the recording medium can be reduced, and damage to the recording medium and the magnetic head can be suppressed.

  In the present invention, all of the plurality of second coil pieces are rectangular and arranged so as to be parallel to each other, or all of the plurality of second coil pieces are V-shaped. The second coil pieces are preferably arranged so that the sides of the second coil pieces are parallel to each other.

  Since the second coil piece is formed across the upper core layer, the second coil piece straddles the step formed by the side surface of the upper core layer. When the second coil piece has a simple shape such as a rectangular shape or a plane-symmetric shape such as a V shape, the second coil piece is formed to have a predetermined shape and a uniform film thickness. Easy to do.

  In the present invention, when the second coil piece is formed to extend in a second direction orthogonal to the first direction, the magnetic field induction efficiency for the upper core layer and the lower core layer is increased. Is preferable.

  In addition, it is preferable that the plurality of first coil pieces overlap with the upper core layer or be arranged in parallel with each other because the efficiency of magnetic field induction with respect to the upper core layer and the lower core layer is improved. .

  In particular, it is more preferable that a portion overlapping the upper core layer of the first coil piece is formed so as to extend in a direction parallel to the second direction.

  Further, in the present invention, on the lower core layer, the lower magnetic pole layer, the gap layer, and the upper magnetic pole layer that is the magnetic layer are arranged in this order from the bottom, and the facing surface of the laminated structure The track width Tw can be determined by the width dimension in the track width direction.

  In the present invention, a laminated structure having a lower magnetic pole layer, a gap layer, and an upper magnetic pole layer is connected to the lower core layer on the side facing the recording medium and in the height direction, and the laminated structure is placed on the first coil piece. It can be formed flat.

  Alternatively, in the present invention, at least the lower magnetic pole layer, the gap layer formed of a nonmagnetic metal material, and the upper magnetic pole layer are sequentially formed on the lower core layer in order from the bottom, and the end surface on the side facing the recording medium is formed. A magnetic pole end layer whose track width Tw is defined by a width dimension in the track width direction may be provided, and the magnetic layer may be laminated on the magnetic pole end layer.

  In the present invention, the magnetic pole end layer is formed at an end of the lower core layer facing the recording medium, and the magnetic layer connects the height side of the lower core layer and the magnetic pole end layer. Become a layer. The first coil piece and the second coil piece are wound around the magnetic layer that is the upper core layer.

  In the present invention in which the magnetic layer is an upper core layer, the magnetic layer preferably has a lower saturation magnetic flux density than the upper magnetic pole layer in order to prevent magnetic recording outside the recording track width.

In the present invention, in order to reduce the heat generation of the toroidal coil layer, the length dimension in the third direction orthogonal to the direction in which the current of the second coil piece flows is the third dimension of the first coil piece. It is preferable that it is larger than the length dimension of this direction.
In the present invention, since the second coil piece can be formed also on the back gap layer, even if the length dimension in the third direction of the second coil piece is increased, the upper core layer and the lower core layer The size can be the same as or smaller than the conventional one, and the inductance of the magnetic head can be reduced.

  Moreover, it is preferable that the film thickness of the said 2nd coil piece is larger than the film thickness of the said 1st coil piece.

  In the present invention, by forming the second coil piece also on the back gap layer, the second coil piece can be formed even if the size of the upper core layer and the lower core layer is the same as or smaller than the conventional one. Since the cross-sectional area of the second coil piece can be maintained large, the DC resistance value of the second coil piece can be reduced. Therefore, the Joule heat generated by the recording current flowing through the coil layer can be reduced, the temperature rise inside the magnetic head can be suppressed, and the recording medium at the tip of the magnetic head made of a metal material can be controlled even when the recording frequency is increased. Protrusion from the facing surface can be suppressed. That is, the frequency with which the magnetic head collides with the recording medium can be reduced, and damage to the recording medium and the magnetic head can be suppressed.

  FIG. 1 is an overall perspective view showing a magnetic head device in which the magnetic head of the present invention is mounted on a slider, FIG. 2 is a partial vertical view showing the structure of the magnetic head according to the first embodiment of the present invention, and FIG. FIG. 3 is a partial plan view of the magnetic head shown in FIG. 2.

  In the following, the X direction shown in the figure is called the track width direction, and the Y direction shown in the figure is called the height direction. The height direction corresponds to the first direction of the present invention, and the track width direction corresponds to the second direction of the present invention.

  The Z direction shown in the figure is the traveling direction of the recording medium (magnetic disk). Further, the front end surface (the leftmost surface shown in FIG. 2) of the magnetic head is referred to as “a surface facing the recording medium”. Further, in each layer, “front end surface (front end portion)” refers to the left surface in FIG. 2 and “rear end surface (rear end portion)” refers to the right surface in FIG.

  The magnetic head described with reference to the drawings is a magnetic head in which a recording head (also referred to as an inductive head) and a reproducing head (also referred to as an MR head) are combined, but a magnetic head composed only of the recording head. It may be a head.

Reference numeral 20 denotes a slider formed of alumina titanium carbide (Al ₂ O ₃ —TiC) or the like, and its facing surface 20a faces the recording medium. As shown in FIG. 1, a magnetic head H, terminal portions P1, P1, and terminal portions P2, P2 are formed on an end portion 20b of the slider 20 on the trailing side. The toroidal coil layer 42 of the inductive head constituting the magnetic head H is connected to the terminal portions P1 and P1 through the lead layer. When the MR head magnetoresistive effect element is provided, a detection current is applied to the magnetoresistive effect element from the terminal portions P2 and P2, and a reproduced magnetic signal is obtained from the terminal portions P2 and P2.

As shown in FIG. 2, an Al ₂ O ₃ layer 21 is formed on the slider 20.
A lower shield layer 22 made of NiFe alloy or sendust is formed on the Al ₂ O ₃ layer 21, and a lower gap layer or upper gap made of Al ₂ O ₃ or the like is formed on the lower shield layer 22. A gap layer 23 composed of layers is formed.

  A magnetoresistive element 24 typified by a GMR element such as a spin valve thin film element is formed in the gap layer 23, and the front end face of the magnetoresistive element 24 is exposed from the surface facing the recording medium. .

  An upper shield layer 25 made of NiFe alloy or the like is formed on the gap layer 23.

  The portion from the lower shield layer 22 to the upper shield layer 25 is called a reproducing head (also referred to as an MR head).

As shown in FIG. 2, a separation layer 28 made of Al ₂ O ₃ or the like is formed on the upper shield layer 25. The upper shield layer 25 and the separation layer 28 may not be provided, and the next lower core layer 29 may be provided on the upper gap layer 26. In such a case, the lower core layer 29 also serves as an upper shield layer.

  In FIG. 2, a lower core layer 29 is formed on the separation layer 28. The lower core layer 29 is made of a magnetic material such as a NiFe alloy. The lower core layer 29 is formed with a predetermined length dimension in the height direction (Y direction in the drawing) from the surface facing the recording medium.

  On the lower core layer 29, a magnetic pole end layer (raised layer) 30 formed with a predetermined length dimension is formed from the surface facing the recording medium in the height direction (Y direction in the figure).

  The pole end layer 30 is formed with a track width Tw in the track width direction (X direction in the drawing). For example, the track width Tw is 0.5 μm or less.

  In the embodiment shown in FIG. 2, the magnetic pole end layer 30 has a laminated structure of a three-layer film of a lower magnetic pole layer 31, a gap layer 32, and an upper magnetic pole layer 33.

  On the lower core layer 29, a lower magnetic pole layer 31 which is the lowest layer of the magnetic pole end layer 30 is formed by plating. The lower magnetic pole layer 31 is formed using a magnetic material and is magnetically connected to the lower core layer 29. The lower magnetic pole layer 31 may be formed of the same material as or different from the lower core layer 29. Good. Either a single layer film or a multilayer film may be used.

A nonmagnetic gap layer 32 is stacked on the bottom pole layer 31.
The gap layer 32 is preferably made of a nonmagnetic metal material and is plated on the lower magnetic pole layer 31. As the nonmagnetic metal material, it is preferable to select one or more of NiP, NiReP, NiPd, NiW, NiMo, NiRh, NiRe, Au, Pt, Rh, Pd, Ru, Cr, and the gap layer 32 is Either a single layer film or a multilayer film may be used.

  On the gap layer 32, an upper magnetic pole layer 33 is formed by plating. In the present embodiment, the upper magnetic pole layer 33 has a laminated structure of a lower layer 33a and an upper layer 33b. The lower layer 33a and the upper layer 33b are made of a magnetic material, and the saturation magnetic flux density of the lower layer 3a is larger than the saturation magnetic flux density of the upper layer 33b.

  As described above, if the gap layer 32 is formed of a nonmagnetic metal material, the lower magnetic pole layer 31, the gap layer 32, and the upper magnetic pole layer 33 can be continuously formed by plating.

  Further, a back gap layer 34 is formed on the lower core layer 29 at a position away from the rear end face in the height direction of the magnetic pole end layer 30 in the height direction (Y direction in the drawing).

  The back gap layer 34 is made of a magnetic material and may be made of the same material as the lower core layer 29 or may be made of a different material. Further, the back gap layer 34 may be a single layer or may be formed in a multilayer structure. The back gap layer 34 is magnetically connected to the lower core layer 29.

  A coil insulating base layer 35 is formed on the lower core layer 29 between the pole end layer 30 and the back gap layer 34, and a portion overlapping the upper core layer 39 on the coil insulating base layer 35 is in the track width direction (illustrated). A plurality of first coil pieces 36 extending in parallel with each other in the X direction and formed in parallel with each other are formed side by side in the height direction.

The first coil piece 36 is filled with a coil insulating layer 37 made of an inorganic insulating material such as Al ₂ O ₃ . As shown in FIG. 2, the top surface of the pole tip layer 30, the top surface of the coil insulating layer 37, and the top surface of the back gap layer 34 are continuous flat surfaces.

  On the lower core layer 29, a Gd determining layer 38 is formed from the position facing the recording medium in the height direction (Y direction in the drawing) from the position away from the surface in the height direction. The rear end portion of the upper magnetic pole layer 33 is placed on the Gd determining layer 38. The gap depth (Gd) is determined by the length in the height direction (Y direction in the drawing) from the surface of the gap layer 32 facing the recording medium until it hits the Gd determining layer 38.

  An upper core layer (magnetic layer) 39 is formed on the upper magnetic pole layer 33 and the back gap layer 34 by plating. The upper core layer 39 connects the height side of the lower core layer 29 and the pole tip layer 30 via the back gap layer 34, and the upper core layer 39 corresponds to the magnetic layer of the present invention.

  The upper magnetic pole layer 33 and the upper core layer 39 may be formed of the same material, but are preferably formed of different materials. In particular, it is more preferable that the upper core layer 39 has a lower saturation magnetic flux density than the upper layer 33 b of the upper magnetic pole layer 33. The saturation magnetic flux density of the upper core layer 39 is, for example, 1.4T to 1.9T, and the saturation magnetic flux density of the upper magnetic pole layer 33 is, for example, 1.9T to 2.4T for the lower layer and 1.4T to 1.9T for the upper layer.

  When the saturation magnetic flux density of the upper core layer 39 is lower than the saturation magnetic flux density of the upper magnetic pole layer 33, it becomes easy to prevent magnetic recording by a leakage magnetic field from the upper core layer 39.

As shown in FIG. 2, an insulating layer 40 made of an insulating material such as Al ₂ O ₃ is formed on the upper core layer 39. The insulating layer 40 is preferably formed of an inorganic insulating material.

As shown in FIG. 2, a plurality of second coil pieces 41 are formed on the insulating layer 40.
The ends of the first coil piece 36 and the second coil piece 41 in the track width direction are electrically connected to each other via a connection layer 42a shown in FIG. A toroidal coil layer 42 having a coil piece 41 and wound around the upper core layer 39 is formed.

A protective layer 43 made of an insulating material such as Al ₂ O ₃ or AlSiO is formed on the toroidal coil layer 42. Note that an insulating layer 44 is behind the lower core layer 29 and the back gap layer 34 in the height direction.

  When a recording current is applied to the coil layer 42, a recording magnetic field is induced in the lower core layer 29 and the upper core layer 39, and a leakage magnetic field is generated between the lower magnetic pole layer 31 and the upper magnetic pole layer 33 facing each other through the gap layer 32. However, a magnetic signal is recorded on a recording medium such as a hard disk by the leakage magnetic field.

FIG. 3 shows a partial plan view of the magnetic head shown in FIG. 2 as viewed from above.
In the magnetic head shown in FIG. 3, all of the plurality of second coil pieces 41 are rectangular and are arranged in parallel to each other.

  A second coil piece 41 is also formed on the back gap layer 34, and the second coil piece 41 has a similar shape to the other second coil pieces 41. The direction of the induction magnetic field generated from the same direction is the same.

  The “similar shape” in the present invention means that the sides facing each other of the two second coil pieces 41 adjacent to each other are in a parallel state. In other words, the interval between a certain second coil piece 41 and the adjacent second coil piece 41 may be a constant value S1 at all positions, and the width dimension W1 in the height direction of each second coil piece 41 is equal to each second. Each coil piece 41 may be different.

  The second coil piece 41 is not formed on the upper core layer 39 only within the range of the front surface 34a facing the recording medium from the front end surface 34a of the back gap layer 34, but on the back gap layer 34. Also formed.

  Therefore, even if the size of the upper core layer 39 and the lower core layer 29 is the same as or smaller than the conventional size, the cross-sectional area of the second coil piece 41 can be maintained large, so that the DC resistance value of the second coil piece 41 is reduced. it can.

  As a result, the magnetic head of the present embodiment can reduce Joule heat generated by the recording current flowing through the coil layer 42, suppress the temperature rise inside the magnetic head, and can be made of a magnetic material made of a metal material even when the recording frequency increases. Protrusion of the head tip portion from the surface facing the recording medium can be suppressed.

  That is, the frequency with which the magnetic head collides with the recording medium can be reduced, and damage to the recording medium and the magnetic head can be suppressed.

  In the present embodiment, each second coil piece 41 is formed so as to extend in the track width direction (second direction) orthogonal to the height direction (Y direction in the figure) that is the first direction. As a result, an induced magnetic field in the height direction can be applied to the upper core layer 39 formed to extend in the height direction, and the recording efficiency can be increased.

  Further, the first coil pieces 36 of the portion C overlapping the upper core layer 39 (hatched with hatching in FIG. 3) are arranged parallel to each other. Further, the first coil piece 36 of the portion C overlapping with the upper core layer 39 is formed to extend in the track width direction (second direction). As a result, an induced magnetic field in the height direction can be applied to the upper core layer 39 formed to extend in the height direction, and the recording efficiency can be increased.

  As shown in FIG. 3, the second coil piece 41 extending in the track width direction and the toroidal portion C are extended in the track width direction (second direction) while overlapping the upper core layer 39 of the first coil piece 36. In order to form a coil, the first coil piece 36 of the portion S extending on both sides of the upper core layer 39 is bent in the height direction.

  Since the first coil piece 36 is formed on the coil insulating base layer 35 that is a flat surface, even if both sides are bent, a pattern can be formed with an accurate shape and a uniform film thickness.

  The length dimension W1 in the third direction orthogonal to the direction in which the current of the second coil piece 41 flows is larger than the length dimension W2 in the third direction of the first coil piece 36. In FIG. 3, the third direction is the height direction and is the same direction as the second direction.

  In the present embodiment, since the second coil piece 41 can also be formed on the back gap layer 34, even if the length dimension W1 in the height direction (third direction) of the second coil piece 41 is increased, The size of the core layer 39 and the lower core layer 29 can be made the same as or smaller than the conventional one, and the inductance of the magnetic head can be made smaller.

  As shown in FIG. 2, the DC resistance value of the coil layer 42 is reduced by making the film thickness t1 of the second coil piece 41 larger than the film thickness t2 of the first coil piece 36, and the amount of heat generated. And the protrusion amount of the magnetic pole end layer 30 can be reduced.

  FIG. 4 is a plan view of the magnetic head according to the second embodiment of the present invention. This embodiment is different from the magnetic head of the first embodiment shown in FIGS. 2 and 3 in that the shape of all the second coil pieces 51 is V-shaped. Other components such as the piece 36 are the same as those of the magnetic head of the first embodiment. The second coil piece 51 and the first coil piece 36 are connected to each other through the connection layer 42 a at the end, and a toroidal coil layer wound around the upper core layer 39 is formed.

  As shown in FIG. 4, the side 51 a and the side 51 b of the second coil piece 51 are arranged so as to be parallel to each other. Further, the length dimension W3 in the third direction orthogonal to the direction in which the current of the second coil piece 51 flows is larger than the length dimension W2 of the first coil piece 36 in the third direction.

  If the second coil piece 51 has a plane-symmetrical shape with respect to a vertical plane passing through the alternate long and short dash line M, such as a V shape, the second coil piece 51 straddles the step formed by the side surface of the upper core layer 39. It becomes easy to form the second coil piece 51 having a predetermined shape and a uniform film thickness.

  Also in the present embodiment, the second coil piece 51 is formed on the back gap layer 34. The second coil piece 51 has a similar shape to the other second coil pieces 51, and the direction of the induction magnetic field generated from each second coil piece 51 is the same direction.

  Therefore, even if the size of the upper core layer 39 and the lower core layer 29 is the same as or smaller than the conventional size, the cross-sectional area of the second coil piece 51 can be maintained large, so that the DC resistance value of the second coil piece 51 is reduced. In addition, the heat generation of the magnetic head can be suppressed and the protrusion of the tip portion of the magnetic head from the surface facing the recording medium can be suppressed. That is, the frequency with which the magnetic head collides with the recording medium can be reduced, and damage to the recording medium and the magnetic head can be suppressed.

  The “similar shape” in the present invention means that the sides 51 a and 51 b facing each other of the two adjacent second coil pieces 51 are in a parallel state. That is, the interval between a certain second coil piece 51 and the adjacent second coil piece 51 only needs to be a constant value S2 at all positions, and the width dimension in the height direction of each second coil piece 51 is equal to each second coil piece. Each piece 51 may be different.

  In the present invention, if the second coil piece has a plane-symmetric shape, the second coil piece straddles the step formed by the side surface of the upper core layer. It becomes easy to form the second coil piece having a predetermined shape and a uniform film thickness.

  Here, as shown in FIG. 5, when the second coil piece 50 is curved in the height direction (Y direction), the second coil piece starts from the end point 50 b of the rear end side 50 a of the second coil piece 50. The angle θ formed by the perpendicular line drawn to the 50 symmetry plane (in the vertical plane passing through the alternate long and short dash line M) and the straight line connecting the end point 50b and the center point 50c of the rear end side 50a is 0 ° or more and 30 ° or less. preferable.

  FIG. 6 is a plan view of a magnetic head according to a third embodiment of the present invention. In the present embodiment, the second coil piece 52 has a rectangular shape and extends in an acute angle direction with respect to the track width direction (second direction: X direction in the figure), and the first coil piece 53 It differs from the magnetic head of the first embodiment shown in FIGS. 2 and 3 in that it has a rectangular shape extending in the track width direction. Other components such as the upper core layer 39 are the same as those of the first embodiment. It is the same as the magnetic head of the form.

  In the present invention, a second coil piece similar in shape to the other second coil pieces may be formed on the back gap layer. As shown in FIG. 6, the second coil piece is formed on the back gap layer 34. All of the second coil pieces 52 including the second coil pieces 52 may be inclined at an equal acute angle with respect to the track width direction.

  This is because if all the second coil pieces 52 are inclined at the same acute angle with respect to the track width direction, an induced magnetic field is generated from all the second coil pieces 52 in the same direction.

  In the present invention, each first coil piece may be inclined and extended in the height direction from the track width direction (X direction in the drawing).

In the present invention, the second coil piece is formed on the back gap layer means that at least a part of the second coil piece is formed behind the front end face of the back gap layer in the height direction. means. Therefore, as shown in FIG. 6, at least one part of the second coil piece 52 only needs to overlap the back gap layer 34.
Alternatively, two or more second coil pieces may overlap the back gap layer 34.

  Further, as shown in FIG. 7, the second coil piece 41a located on the back side in the most height direction (the Y direction in the drawing; the first direction) formed on the back gap layer 34 is the rear end face 34b of the back gap layer 34. Further, it may be formed so as to extend deeper in the height direction. In the magnetic head shown in FIG. 7, the width dimension W4 in the height direction of the second coil piece 41a is larger than the width dimension W1 in the height direction of the other second coil pieces 41.

  As described above, the “similar shape” in the present invention means that the opposite sides of two adjacent second coil pieces 41 are in a parallel state, and the second coil piece 41 and the second coil piece 41a. The interval may be a constant value at all positions.

  The magnetic head shown in FIG. 2 to FIG. 7 is formed by plating a lower magnetic pole layer 31, a gap layer 32 made of a nonmagnetic metal material, and an upper magnetic pole layer 33 in this order on the lower core layer 29 from the bottom. The magnetic pole end layer 30 defining the width Tw is provided, and the upper core layer 39 that is a magnetic layer is laminated on the magnetic pole end layer 30.

  In the magnetic head of the present invention, as shown in FIGS. 8 and 9 below, a raised layer 60 made of a magnetic material is formed on the lower core layer 29, and on the raised layer 60 and the back gap layer 34. And a bottom pole layer 61, a gap layer 62, and a top pole layer 63, which is a magnetic layer according to the present invention, in this order, and a track width at a surface F facing the recording medium of the laminate structure 64. Including those in which the track width Tw is determined by the width dimension in the direction (X direction).

8 and 9 are a sectional view and a plan view of the magnetic head according to the fifth embodiment of the present invention.
In the magnetic head of the present embodiment, a raised layer 60 made of a magnetic material is formed on the lower core layer 29, and a lower magnetic pole layer 61 and a gap layer are formed on the raised layer 60 and the back gap layer 34 from below. 62 and the upper magnetic pole layer 63 are different from the magnetic head shown in FIGS. 2 and 3 in that the laminated structure 64 and the upper core layer 65 are laminated in this order. This is the same as the magnetic head shown in FIG. For example, the configuration of the first coil piece 36 formed on the lower core layer 29 via the coil insulating base layer 35 and the second coil piece 41 formed on the upper core layer 65 via the insulating layer 40, The structure of the toroidal coil layer formed by connecting the first coil piece 36 and the second coil piece 41 via the connection layer 42a is the same as that of the magnetic head shown in FIGS. The second coil piece 41 at the end in the direction is formed on the back gap layer 34.

The magnetic head described in FIGS. 8 and 9 will be described in detail.
On the lower core layer 29, a raised layer 60 having a predetermined length dimension is formed from the surface facing the recording medium to the height direction (Y direction in the drawing). Further, a back gap layer 34 is formed on the lower core layer 29 at a position away from the rear end surface 60 a in the height direction of the raised layer 60 in the height direction (Y direction in the drawing).

  The raised layer 60 and the back gap layer 34 are formed of a magnetic material, and may be formed of the same material as the lower core layer 29 or may be formed of a different material. Further, the raised layer 60 and the back gap layer 34 may be a single layer or may be formed of a multilayer structure. The raised layer 60 and the back gap layer 34 are magnetically connected to the lower core layer 29.

  As shown in FIG. 8, a plurality of first coil pieces 36 are formed on the coil insulating base layer 35.

The first coil piece 36 is filled with a coil insulating layer 37 made of an inorganic insulating material such as Al ₂ O ₃ . As shown in FIG. 8, the upper surface of the raised layer 60, the upper surface of the coil insulating layer 37, and the upper surface of the back gap layer 34 are continuous flat surfaces.

  As shown in FIG. 8, on the planarized surfaces of the raised layer 60 and the coil insulating layer 37, Gd from the position facing the recording medium in the height direction (Y direction shown in the drawing) from the position in the height direction toward the height direction. A determining layer 66 is formed.

  Further, as shown in FIG. 8, on the raised layer 60 from the surface facing the recording medium to the front end surface 66a of the Gd determining layer 66, on the coil insulating layer 37 in the height direction from the rear end surface 66b of the Gd determining layer 66, and back A lower magnetic pole layer 61 and a gap layer 62 are formed on the gap layer 34 from below. The bottom pole layer 61 and the gap layer 62 are formed by plating. The dimension of the gap layer 62 in the height direction is determined by the Gd determining layer 66.

  Further, as shown in FIG. 8, an upper magnetic pole layer 63, which is a magnetic layer of the present invention, is formed on the gap layer 62 and the Gd determining layer 66, and further, an upper core layer 65 is plated on the upper magnetic pole layer 63. Is formed. The upper magnetic pole layer 63 is directly or indirectly connected to the lower core layer 29 through the back gap layer 34. The lower magnetic pole layer 61, the gap layer 62, and the upper magnetic pole layer 63 are the laminated structure 64 of the present invention.

  In this embodiment, the laminated body 70 is composed of four layers of the lower magnetic pole layer 61, the gap layer 62, the upper magnetic pole layer 63, and the upper core layer 65.

  The lower magnetic pole layer 61, the upper magnetic pole layer 63, and the upper core layer 65 are made of a magnetic material, and the gap layer 62 is made of a nonmagnetic material such as NiP or NiReP.

  When viewed from directly above, the laminated body 70 has a form as shown in FIG. 9, for example. The front end region 70b on the side facing the recording medium of the stacked body 70 is formed with a narrow width dimension in the track width direction (X direction in the figure), and the front end region 70b in the track width direction on the surface facing the recording medium. The track width Tw is determined by the dimensions. The track width Tw is, for example, 0.7 μm or less, and preferably 0.5 μm or less. Further, the rear end region 70c of the stacked body 70 is formed such that the width in the track width direction from the base end of the front end region 70b extends in the height direction (Y direction in the drawing), and the area of the rear end region 70c is the front end region 70b. The area is sufficiently larger than the area.

As shown in FIG. 8, an insulating layer 43 made of an insulating material such as Al ₂ O ₃ is formed on the upper core layer 65. The insulating layer 43 is preferably formed of an inorganic insulating material.

Also in the present embodiment, the second coil piece 41 is formed on the back gap layer 34. The second coil piece 41 has a similar shape to the other second coil pieces 41, and the direction of the induction magnetic field generated from each second coil piece 41 is the same direction.
Therefore, even if the size of the upper core layer 39 and the lower core layer 29 is the same as or smaller than the conventional size, the cross-sectional area of the second coil piece 41 can be increased, so that the DC resistance value of the second coil piece 41 can be reduced. Further, the heat generation of the magnetic head can be suppressed, and the protrusion of the tip portion of the magnetic head from the surface facing the recording medium can be suppressed. That is, the frequency with which the magnetic head collides with the recording medium can be reduced, and damage to the recording medium and the magnetic head can be suppressed.

An overall perspective view of a slider on which the magnetic head of the present invention is formed, 1 is a longitudinal sectional view showing the structure of a magnetic head according to a first embodiment of the invention, FIG. 1 is a partial plan view of the thin film magnetic head shown in FIG. A partial plan view showing the structure of a magnetic head according to a second embodiment of the present invention, The fragmentary top view which shows other embodiment of the 2nd coil piece of this invention, FIG. 7 is a partial plan view showing the structure of a magnetic head according to a third embodiment of the invention. A longitudinal sectional view showing the structure of a magnetic head according to a fourth embodiment of the present invention, A longitudinal sectional view showing a structure of a magnetic head according to a fifth embodiment of the present invention, FIG. 9 is a partial plan view of the thin film magnetic head shown in FIG. A longitudinal sectional view showing the structure of a conventional magnetic head, FIG. 10 is a partial plan view of the thin film magnetic head shown in FIG. A partial plan view showing the structure of a conventional magnetic head,

Explanation of symbols

29 Lower core layer 30 Magnetic pole end layer 34 Back gap layer 36 First coil piece 39 Upper core layers 41, 51, 52 Second coil piece 64 Laminated structure

Claims (11)

A lower core layer formed extending in the first direction from the surface facing the recording medium, and the lower core via a back gap layer made of a magnetic material at a predetermined distance from the lower core layer. Having a magnetic layer connected directly or indirectly to the layer at the height side,
The ends in the track width direction of the plurality of first coil pieces formed on the lower side of the magnetic layer and the ends in the track width direction of the plurality of second coil pieces formed on the upper side of the magnetic layer are electrically connected. Connected to each other, and a toroidal coil layer formed around the magnetic layer having the first coil piece and the second coil piece is formed,
A magnetic head, wherein a second coil piece similar in shape to another second coil piece is formed on the back gap layer.   The magnetic head according to claim 1, wherein all of the plurality of second coil pieces have a rectangular shape and are arranged in parallel to each other.   The magnetic head according to claim 2, wherein the second coil piece is formed to extend in a second direction orthogonal to the first direction.   2. The magnetic head according to claim 1, wherein all of the plurality of second coil pieces are V-shaped, and are arranged so that the sides of the second coil pieces are parallel to each other.   5. The magnetic head according to claim 1, wherein the plurality of first coil pieces are arranged so as to overlap with an upper core layer or to be parallel to each other.   6. The magnetic head according to claim 5, wherein a portion of the first coil piece that overlaps the upper core layer is formed to extend in a direction parallel to the second direction orthogonal to the first direction.   A width in the track width direction on the facing surface of the stacked structure having a stacked structure in which a lower magnetic pole layer, a gap layer, and an upper magnetic pole layer, which is the magnetic layer, are formed in order from the bottom on the lower core layer 7. The magnetic head according to claim 1, wherein the track width Tw is determined by the dimension.   On the lower core layer, at least the lower magnetic pole layer, the gap layer formed of a nonmagnetic metal material, and the upper magnetic pole layer are plated in this order, and the end surface on the side facing the recording medium in the track width direction is plated. The magnetic head according to claim 1, wherein a magnetic pole end layer whose track width Tw is defined by a width dimension is provided, and the magnetic layer is laminated on the magnetic pole end layer.   The magnetic head according to claim 8, wherein the magnetic layer has a saturation magnetic flux density lower than that of the upper magnetic pole layer.   The length dimension in the third direction orthogonal to the direction in which the current of the second coil piece flows is larger than the length dimension in the third direction of the first coil piece. The magnetic head described.   The magnetic head according to claim 1, wherein a film thickness of the second coil piece is larger than a film thickness of the first coil piece.

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