JPH0636236A - Composite thin-film magnetic head - Google Patents

Abstract

PURPOSE:To provide a composite thin-film magnetic head wherein the peak shift of a reproduced waveform can be reduced. CONSTITUTION:A composite thin-film magnetic head is formed by combining an MR head part 10 for reproduction with an inductive head part 11, for recording, which has been laminated and formed on the MR head part 10. The MR head part 10 is constituted in such a way that it detects only a magnetic pole on a track on a magnetic medium and that it does not detect a track-side magnetic pole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductive head for recording on a magnetic medium such as a magnetic disk and a magnetoresistive head (Magneto R) for reproducing from the magnetic medium.
The present invention relates to a composite type thin film magnetic head which is a combination of an essential head (hereinafter referred to as an MR head).

[0002]

2. Description of the Related Art In recent years, MR heads utilizing the magnetoresistive effect have begun to be put into practical use as thin film magnetic heads for magnetic media such as magnetic disks. The MR head has an advantage that a large reproduction output can be obtained irrespective of the relative speed with respect to the magnetic medium. However, since the MR head is only for reproduction, it has a configuration combined with the recording head for use as a recording / reproducing head. There is a need.

FIG. 13 schematically shows a known composite type thin film magnetic head formed by combining an MR head and an inductive head for recording from the bottom side facing the magnetic medium.

In the figure, reference numeral 150 is a reproducing MR head portion, and 151 is a recording inductive head portion provided behind the MR head portion 150.

In this specification, the terms "front" and "rear" mean the front and the rear of the magnetic head relative to the magnetic medium in the traveling direction (see the arrow in the figure).

The MR head section 150 has an insulating base film 153 and a shield layer 15 on the rear end surface of the slider 152.
4, gap insulating film 155, MR element 156, lead 1
57, the gap insulating film 158, and the shield layer 159 are sequentially stacked.

A front magnetic layer 160 and a rear magnetic layer 161 are formed on the inductive head portion 151.
As is clear from the figure, the track width on the magnetic medium is determined by the width of the tip of the shorter magnetic layer, in this example, the width of the bottom surface of the rear magnetic layer 161.

The effective reproducing head width (MR head width) of the MR head section 150 is the lead 157 on the MR element 156.
In the conventional magnetic head, it is set to be substantially equal to or slightly shorter than the head width of the inductive head portion 151.

[0009]

According to the analysis of the inventors of the present application, according to the conventional composite type thin film magnetic head of this type, the following distortion (base line
It was found that transition noise = BLT noise) occurred. FIG. 14 is a diagram for explaining this reproduced waveform distortion, and FIG. 15 is an actual reproduced waveform diagram obtained by the conventional composite type thin film magnetic head having the structure shown in FIG.

In FIG. 14, 162 is a track formed on the magnetic medium by the recording operation of the inductive head section 151, 163 is a magnetization reversal position on the track 162, and 164 is a magnetization direction. This track 1
When the MR head section 150 is used to reproduce 62, ideally, a pulse-shaped reproduction waveform 165 that sharply rises from the ground level 166 at the magnetization reversal position 163 should be obtained. However, when recording / reproducing is performed with the conventional composite type thin film magnetic head, the reproduced waveform 167 becomes a disordered waveform in which the step 167b appears prior to the main pulse 167a. This disturbance of the reproduced waveform is also found from the actually measured waveform chart of FIG.

Since such a waveform disturbance is superposed on the next main pulse, the pulse amplitude is finally changed and the pulse position is changed, resulting in a deterioration of the error rate.

Therefore, the present invention provides a composite type thin film magnetic head capable of reducing the peak shift of the reproduced waveform.

[0013]

According to the present invention, a composite having a novel structure in which an MR head portion for reproduction and an inductive head portion for recording formed by being laminated on the MR head portion are combined with each other. A thin film magnetic head is provided. In this composite type thin film magnetic head, the MR head portion is configured to detect only the magnetic poles on the tracks on the magnetic medium and not the track / side magnetic poles.

It is preferable that the effective head width of the MR head portion is made narrower than the effective head width of the inductive head portion so that only the magnetic poles on the track can be detected.

It is also preferable that the MR head portion is shielded at a position corresponding to the lateral side of the track so as to detect only the magnetic pole on the track.

The core of the inductive head portion is composed of a front magnetic layer (lower magnetic layer) and a rear magnetic layer (upper magnetic layer) located on the front side and the rear side with respect to the relative traveling direction of the magnetic head with respect to the magnetic medium. And
At least the tips of the front magnetic layer and the rear magnetic layer facing the magnetic medium may have a rectangular shape, and the width of the rear magnetic layer may be shorter than the width of the front magnetic layer.

It is more effective if the width of the rear magnetic layer is equal to or larger than the width of the front magnetic layer.

The shape of at least the tip of the rear magnetic layer facing the magnetic medium may be a shape in which two sides thereof are inclined so as to narrow the width toward the rear.

The shape of at least the tip of the front magnetic layer facing the magnetic medium may be a shape in which at least the rear portion of the side edge is inclined rearward so that the width becomes narrower.

[0020]

Since the MR head is configured to detect only the magnetic poles on the tracks on the magnetic medium and not the track-side magnetic poles, the magnetic medium generated by the fringing magnetic field of the inductive head during recording. The influence of the upper track side magnetic pole can be greatly reduced. As a result, as will be described later, the waveform distortion of the reproduced waveform (base line transition noise = BLT noise) is significantly reduced.

[0021]

The present invention will be described in detail with reference to the following examples.

FIG. 2 is a perspective view showing a flying type magnetic head unit having a composite type thin film magnetic head as an embodiment of the present invention.

As shown in the figure, the flying type magnetic head unit of this embodiment has a slider 20 and two composite type thin film magnetic heads 21 provided on the rear end face thereof and a protective film 2 thereof.
It is mainly composed of 2 and. The slider 20 is formed by sputtering a ceramic structure 23 made of a ceramic material such as Al ₂ O ₃ —TiC and an electrically insulating material such as Al ₂ O ₃ or SiO _{2 on} the rear end surface of the ceramic structure 23. And the ground film 24.

The composite type thin film magnetic head 21 is a thin film element formed on the base film 24, and these heads 21 have four electrodes 25 formed so as to be exposed on the surface of the protective film 22 and four leads 26. Are connected to each other.

The protective film 22 is formed by sputtering Al ₂ O ₃ or SiO ₂ or the like, a composite type thin film magnetic head 2
1, the base film 24, and the leads 26 are formed so as to cover the entire surfaces.

FIG. 3 is a partial sectional view taken along the line AA in FIG. 2 to show the structure of the composite type thin film magnetic head 21 in more detail.

On the base film 24 formed on the rear end face of the above-mentioned ceramic structure 23, Ni-containing permalloy or the like is formed.
The shield layer (lower shield layer) 30 is formed by plating an Fe alloy.

The MR element 31 is formed on the shield layer 30.
Are formed so as to be sandwiched between the gap insulating films 32.
That is, the MR element 31 is formed by sputtering and patterning a Ni—Fe alloy such as permalloy on the lower gap insulating film formed by sputtering Al ₂ O ₃ or the like on the shield layer 30. Leads 26 (FIG. 2) made of Cu or the like are formed on the MR element 31 by plating or the like. In addition, a shunt layer for applying a bias to the MR element, a soft film bias layer, and the like are provided as needed by sputtering or the like. MR element 31, lead 2
6 and the upper gap insulating film is formed on the lower gap insulating film by sputtering Al ₂ O ₃ or the like, whereby the gap insulating film 32 is formed.

A shield layer (upper shield layer) 33 is formed on the gap insulating film 32 by plating a Ni-Fe alloy such as permalloy.

The shield layer 30, the MR element 31, the lead 26, the gap insulating film 32, and the shield layer 33 form an MR head portion for reproduction. Shield layer 33
An insulating film 34 is formed on the upper surface by sputtering Al ₂ O ₃ or the like.

On the insulating film 34, Ni-- such as permalloy is formed.
A front magnetic layer (lower magnetic layer) 35 is formed by plating an Fe alloy, and Al ₂ O ₃ or S is formed on the front magnetic layer (lower magnetic layer) 35.
A coil conductor 37 made of Cu, Au, or the like is provided so as to be sandwiched by an insulating film 36 of iO ₂ or the like, and a Ni—Fe alloy such as permalloy is plated on the coil conductor 37 to form a rear magnetic layer (upper magnetic layer). 38 is formed.

The front magnetic layer 35 and the rear magnetic layer 38 are connected to each other at a portion 38a on the side opposite to the surface 39 facing the magnetic medium, thereby forming a core of the inductive head portion for recording. There is. The coil conductor 37 is formed so as to be wound around the coupling portion 38a of the front magnetic layer 35 and the rear magnetic layer 38 in a spiral shape.

The protective film 22 is formed on the rear magnetic layer 38.

It is obvious that the front magnetic layer 35 may be configured so as to also serve as the shield layer 33. In this case, as a matter of course, the insulating film 34
Is omitted.

FIG. 1 shows the composite type thin film magnetic head 21 of this embodiment on the bottom side (the surface 39 in FIG. 3) facing the magnetic medium.
Side).

In the figure, reference numeral 10 is a reproducing MR head portion, and 11 is a recording inductive head portion provided behind the MR head portion 10.

As described above, the MR head portion 10 includes the ceramic structure 23, the base film 24, the lower shield layer 30,
Lower gap insulating film 32a, MR element 31, lead 2
6, the upper gap insulating film 32b, and the upper shield layer 3
3, the inductive head portion 11 has a front magnetic layer 35 and a rear magnetic layer 38 having a width narrower than that (a width in the track width direction).

The effective head width (MR head width) for reproduction of the MR head portion 10 is determined by the interval between the leads 26 on the MR element 31, and the effective head width (track width) of the inductive head portion 11 is. , The narrower width of the rear magnetic layer 38. In the present embodiment, the MR head width is set narrower than the effective head width (track width) of the inductive head portion 11 so that only the magnetic poles on the track are detected.

As described above, by setting the MR head width so that only the magnetic poles on the tracks on the magnetic medium are detected and the track-side magnetic poles are not detected, the fringing magnetic field generated from the rear magnetic layer 38 during recording is set. The effect of can be greatly reduced.

The present inventors have found that by reducing the influence of the fringing magnetic field in this way, the waveform distortion (base line transition noise = BLT noise) of the reproduced waveform is significantly reduced. . This point will be described in detail below.

FIG. 4 is a diagram for explaining the magnetic field generated by the inductive head section 11 and the magnetic poles recorded on the magnetic medium by the magnetic field, and FIG. 5 shows the inductive head section 11 traveling relatively further for recording. FIG. 3 is a diagram illustrating a magnetic field generated by this head when a current is reversed, a magnetic pole recorded on a magnetic medium by this head, and a reproduced waveform when this track is read by a conventional MR head unit 10.

As is clear from FIG. 4, in the inductive head portion 11, the width of the bottom surface of the front magnetic layer 35 is considerably larger than the width of the bottom surface of the rear magnetic layer 35. , That gap when recording 4
In addition to the original magnetic field 41 generated at 0, a magnetic field (fringing magnetic field) 42 is also generated from the side portion of the rear magnetic layer 38. Due to this magnetic field 42, the outer portion of the edge of the track 43 on the magnetic medium is magnetized obliquely in the direction shown in FIG.
The side magnetic pole 44 is formed.

It is assumed that the inductive head further travels relatively and the recording current is reversed at the position shown in FIG. As a result, the magnetization direction is reversed, and the vicinity of the front surface 38a of the rear magnetic layer 38 at that time becomes the magnetization reversal position (bit position) 45 on the track 43, and the original magnetic pole 46 is formed on this track 43. At this time, at the same time, the rear magnetic layer 161
Since a fringing magnetic field 47 toward the side of
The outer portion of the edge of the track 43 is obliquely magnetized in the direction opposite to the front to form the track side magnetic pole 48.
In the figure, reference numeral 50 denotes a reversal region of the track-side magnetic pole, and the length of the reversal region 50 in the track direction is substantially equal to the length of the rear magnetic layer 38 in the front-rear direction (length in the track direction).

When the track 43 thus recorded is read by the conventional MR head, the reproduced waveform 49 is formed under the influence of the track side magnetic pole 44 and its reverse track side magnetic pole 48. The step 49b precedes the main pulse 49a at the magnetization reversal position 45 by an amount corresponding to the length of the reversal region 50, and the waveform is disturbed (base line transition).
Noise = BLT noise) occurs.

It should be noted that such a disturbance in the reproduction waveform is peculiar to the appearance when the recording inductive head and the reproduction MR head are used in combination. That is, what is recorded by the inductive head is M which is sensitive to the magnetic potential.
It occurs only when read with the R head,
Even if this is read by an inductive head that is sensitive to the magnetic differentiation, this kind of disturbance in the reproduced waveform hardly appears.

As in this embodiment, if the MR head width is narrowed and the track side magnetic pole 44 and its reverse track side magnetic pole 48 are not detected as much as possible, the reproduction waveform is disturbed (base line transition noise). = BLT noise) can be prevented. As a result, the peak shift of the reproduced waveform can be reduced,
The error rate can be improved.

FIG. 6 schematically shows a composite type thin film magnetic head according to another embodiment of the present invention from the bottom side facing the magnetic medium.

The MR head part is similar to the embodiment of FIG.
Ceramic structure 123, base film 124, lower shield layer 130, lower gap insulating film 132a, MR element 13
1, the lead 126, the upper gap insulating film 132b, and the upper shield layer 133 are sequentially stacked, and the MR head width is made narrower than the track width so that the track / side magnetic poles are not detected as much as possible. The head portion has a front magnetic layer 135 and a rear magnetic layer 138 having a configuration different from that of the embodiment of FIG.

That is, in this embodiment, the front magnetic layer 13
5 and the bottom surface of the rear magnetic layer 138 facing the magnetic medium are both rectangular, and the width of the rear magnetic layer 138 on the bottom surface is set to be substantially equal to the width of the front magnetic layer 135.

With this configuration, the fringing magnetic field itself generated from the rear magnetic layer 138 during recording can be significantly reduced.

As in the present embodiment, the width of the MR head is narrowed so that the track side magnetic pole 44 and its reverse track side magnetic pole 48 are not detected as much as possible, and fringing magnetic fields 42 and 47 are generated as much as possible. If it is configured so that it does not occur, it is possible to more effectively prevent the disturbance of the reproduced waveform. As a result, the peak shift of the reproduced waveform can be further reduced, and the error rate can be further improved.

FIG. 7 schematically shows a composite type thin film magnetic head according to still another embodiment of the present invention from the bottom side facing the magnetic medium.

The MR head part is similar to the embodiment of FIG.
Ceramic structure 223, base film 224, lower shield layer 230, lower gap insulating film 232a, MR element 23
1, the lead 226, the upper gap insulating film 232b, and the upper shield layer 233 are sequentially stacked, and the MR head width is made narrower than the track width so that the track / side magnetic poles are not detected as much as possible. The head portion has a front side magnetic layer 235 and a rear side magnetic layer 238 having a configuration different from that of the embodiment of FIG.

That is, in this embodiment, the front magnetic layer 23
5 and the bottom surface of the rear magnetic layer 238 facing the magnetic medium are both rectangular, and the width of the rear magnetic layer 238 on the bottom surface is longer than the width of the front magnetic layer 235 (length in the track width direction). It is set.

With this structure, the fringing magnetic field itself generated from the side portion of the rear magnetic layer 238 during recording can be greatly reduced. As a result, MR
Coupled with the effect of narrowing the head width and not detecting the track side magnetic poles as much as possible, the waveform distortion of the reproduced waveform can be greatly reduced for the same reason as in the embodiment of FIG.

Other constitutions and operational effects of this embodiment are the same as those of the embodiment of FIG.

FIG. 8 schematically shows a composite type thin film magnetic head according to still another embodiment of the present invention from the bottom side facing the magnetic medium.

The MR head part is similar to the embodiment of FIG.
Ceramic structure 323, base film 324, lower shield layer 330, lower gap insulating film 332a, MR element 33
1, the lead 326, the upper gap insulating film 332b, and the upper shield layer 333 are sequentially stacked, and the MR head width is made narrower than the track width so that the track / side magnetic poles are not detected as much as possible. The head portion has a front side magnetic layer 335 and a rear side magnetic layer 338 having a configuration different from that of the embodiment of FIG.

That is, in this embodiment, the front magnetic layer 33 is formed.
The bottom surface of the rear magnetic layer 338 facing the magnetic medium is trapezoidal, while the bottom surface of the rear magnetic layer 338 facing the magnetic medium is trapezoidal. Moreover, the front side 338a is set to be the base of the trapezoid.

In this embodiment, the rear magnetic layer 3
The width of the bottom surface of 38 (the length of the front side 338a) is the front magnetic layer 3
The width of the bottom surface of the rear magnetic layer 338 is smaller than the width of the bottom surface of the front magnetic layer 335, as in the embodiment of FIG. 6 or 7. May be set as follows.

By thus forming the trapezoidal shape having the front side 338a as the bottom side, the two side sides of the rear magnetic layer 338 are inclined rearward and inward, so that these side sides and the front magnetic layer 335 are formed. And the magnetic path length between the two becomes longer as the coupling with the direction magnetically weakens.
The fringing field itself resulting from 38 can be significantly reduced. As a result, in combination with the effect of narrowing the MR head width and not detecting the track side magnetic poles as much as possible, the waveform distortion of the reproduced waveform can be greatly reduced for the same reason as in the embodiment of FIG. Further, since the substantial length in the front-rear direction of the side portion of the rear magnetic layer 338 is sufficiently shortened, the length of the inversion region 50 is shortened, and the step 4 is formed.
Since 9b is absorbed by the main pulse 49a, the disturbance of the reproduced waveform can be prevented from this point as well.

Other constitutions and operational effects of this embodiment are the same as those of the embodiment of FIG.

FIG. 9 schematically shows a composite type thin film magnetic head according to still another embodiment of the present invention from the bottom side facing the magnetic medium.

The MR head portion is similar to the embodiment of FIG.
Ceramic structure 423, base film 424, lower shield layer 430, lower gap insulating film 432a, MR element 43
1, the lead 426, the upper gap insulating film 432b, and the upper shield layer 433 are sequentially stacked, and the MR head width is made narrower than the track width so that the track / side magnetic poles are not detected as much as possible. The head portion has a front magnetic layer 435 and a rear magnetic layer 438 having a configuration different from that of the embodiment of FIG.

That is, in this embodiment, the front magnetic layer 43 is formed.
The bottom surface of the back magnetic layer 438 facing the magnetic medium is triangular, while the bottom surface of the back magnetic layer 438 facing the magnetic medium is triangular. Moreover, the front side 438a is set to be the base of the triangle.

In this embodiment, the rear magnetic layer 4
The width of the bottom surface of 38 (the length of the front side 438a) is the front magnetic layer 4
The width of the bottom surface of the rear magnetic layer 438 is set to be smaller than the width of the bottom surface of the front magnetic layer 435 as in the embodiment of FIG. 6 or 7. May be set as follows.

By thus forming the triangular shape having the front side 438a as the bottom side, the two side sides of the rear side magnetic layer 438 are inclined rearward and inward, so that these side sides and the front side magnetic layer 435 are formed. As the coupling between the magnetic field and the magnetic field becomes weaker in direction and the magnetic path length between the two becomes longer, the fringing magnetic field itself generated from the rear magnetic layer 438 during recording can be considerably reduced. As a result, in combination with the effect of narrowing the MR head width and not detecting the track side magnetic poles as much as possible, the waveform distortion of the reproduced waveform can be greatly reduced for the same reason as in the embodiment of FIG. Further, since the substantial length in the front-rear direction of the side portion of the rear magnetic layer 438 is sufficiently shortened, the length of the inversion region 50 is shortened, and the step 49b is absorbed by the main pulse 49a. Also from this point of view, the disturbance of the reproduced waveform can be prevented.

Other constitutions and operational effects of this embodiment are the same as those of the embodiment of FIG.

The shape of the bottom surface of the rear side magnetic layer is not limited to the trapezoidal shape or the triangular shape as in the embodiments of FIGS. 8 and 9, and the widths of the two sides are narrowed rearward. Any shape may be used as long as it is inclined. Further, the side edge does not necessarily have to be a straight line, and may be a curved line.

FIG. 10 schematically shows a composite type thin film magnetic head according to still another embodiment of the present invention from the bottom side facing the magnetic medium.

The MR head part is similar to the embodiment of FIG.
Ceramic structure 523, base film 524, lower shield layer 530, lower gap insulating film 532a, MR element 53
1, the lead 526, the upper gap insulating film 532b, and the upper shield layer 533 are sequentially laminated, and the MR head width is made narrower than the track width so that the track / side magnetic poles are not detected as much as possible. The head portion has a front side magnetic layer 535 and a rear side magnetic layer 538 having a configuration different from that of the embodiment of FIG.

That is, in this embodiment, the rear magnetic layer 53 is formed.
8 has a rectangular bottom surface facing the magnetic medium, the front magnetic layer 535 has a trapezoidal bottom surface facing the magnetic medium. Moreover, the front side 535a is set to be the base of the trapezoid. The length of the rear side 535b of the bottom surface of the front magnetic layer 535 is substantially equal to the width of the bottom surface of the rear magnetic layer 538.

Thus, by making the shape of the bottom surface of the front magnetic layer 535 into a trapezoidal shape having the front side 535a as the base, the two side edges of the front magnetic layer 535 are inclined inwardly toward the rear. The coupling between the two side surfaces of the side magnetic layer 538 and the front magnetic layer 535 weakens directionally and the magnetic path length between them becomes long, so that the rear side magnetic layer 538 at the time of recording.
The fringing field itself resulting from can be significantly reduced. As a result, in combination with the effect of narrowing the MR head width and not detecting the track side magnetic poles as much as possible, the waveform distortion of the reproduced waveform can be greatly reduced for the same reason as in the embodiment of FIG.

Other constitutions and operational effects of this embodiment are the same as those of the embodiment of FIG.

FIG. 11 schematically shows a composite type thin film magnetic head according to still another embodiment of the present invention from the bottom side facing the magnetic medium.

The MR head part is similar to the embodiment of FIG.
Ceramic structure 623, base film 624, lower shield layer 630, lower gap insulating film 632a, MR element 63
1, the lead 626, the upper gap insulating film 632b, and the upper shield layer 633 are sequentially stacked, and the MR head width is made narrower than the track width so that the track / side magnetic poles are not detected as much as possible. The head portion has a front magnetic layer 635 and a rear magnetic layer 638 having a configuration different from that of the embodiment of FIG.

That is, in this embodiment, the rear magnetic layer 63
The bottom surface of the front magnetic layer 635 facing the magnetic medium has a rectangular shape, but the bottom surface of the front magnetic layer 635 facing the magnetic medium has a shape in which the rear portion of its side is obliquely cut. The length of the rear side 635b of the bottom surface of the front magnetic layer 635 is substantially equal to the width of the bottom surface of the rear magnetic layer 638.

As described above, by forming the rear portions of the side edges obliquely, the rear portions of the two side edges of the front magnetic layer 635 are inclined inwardly toward the rear, so that the rear magnetic layer 638 is formed. Coupling between the two side surfaces and the front magnetic layer 635 becomes weaker in direction and the magnetic path length between them becomes longer, so that the fringing magnetic field itself generated from the rear magnetic layer 638 during recording can be considerably reduced. As a result, M
Coupled with the effect of narrowing the R head width and not detecting the track side magnetic poles as much as possible, the waveform distortion of the reproduced waveform can be further reduced for the same reason as in the embodiment of FIG.

Other constitutions and operational effects of this embodiment are the same as those of the embodiment of FIG.

The shape of the bottom surface of the front magnetic layer is shown in FIG.
And not limited to the embodiment of FIG.
Any shape may be used as long as at least the rear part of one side is inclined rearward so that the width becomes narrower. Further, the side edge does not necessarily have to be a straight line, and may be a curved line.

FIG. 12 schematically shows a composite type thin film magnetic head according to still another embodiment of the present invention.
(A) is a bottom view schematically showing from the bottom side facing the magnetic medium, and (B) is a side view of the MR element portion viewed from the track direction.

In FIG. 9A, 710 is an M for reproduction.
The R head portion and 711 are recording inductive head portions provided behind the MR head portion 710, respectively.

The MR head portion 710 includes a ceramic structure 723, a base film 724, a lower shield layer 730, a lower gap insulating film 732a, an MR element 731, and leads 72.
6, the upper gap insulating film 732b, and the upper shield layer 733 are sequentially stacked, and the inductive head portion 711 includes the front magnetic layer 735 and the rear magnetic layer 735 having a narrower width (length in the track width direction). Magnetic layer 738
have.

In FIG. 7B, reference numeral 760 denotes the surface of the magnetic head facing the magnetic medium, and the MR element 731.
Is on this surface 760 at a position 761 corresponding to the side of the track.
The shape is bent in the direction away from. As a result, the MR element 731 appears on this surface 760 only in the portion 731a that substantially corresponds to the track. Then, outside the position 761 corresponding to the side of the track,
The non-magnetic material 762 separates the MR element 731 to form a shield material 763 for shielding.

As a result, the MR element 731 will detect the magnetic pole only in the portion 731a substantially corresponding to the track. In this way, by shielding only the magnetic pole on the track on the magnetic medium and not detecting the track / side magnetic pole, the rear magnetic layer 738 at the time of recording.
The influence of the fringing magnetic field generated from can be significantly reduced, and the disturbance of the reproduced waveform can be prevented.
As a result, the peak shift of the reproduced waveform can be reduced and the error rate can be improved.

The structure of the MR head is not limited to that of the embodiment shown in FIG. 12, but may be shielded at a position corresponding to the lateral side of the track so as to detect only the magnetic pole on the track.

The configuration of the embodiment of FIG. 12 and FIGS. 1 and 6 to 1
It is obvious that a more excellent effect can be obtained by combining with the configuration of any one of the embodiments.

In all of the above-mentioned embodiments, the shape of the bottom surface of the front magnetic layer and / or the rear magnetic layer which faces the magnetic medium has been described. However, in the magnetic medium of the front magnetic layer and / or the rear magnetic layer, It suffices that at least the tip end facing each other has a shape as described above, and therefore, the cross-sectional shape as described above may be provided over the entire length of the magnetic layer, or the cross section from the bottom surface facing the magnetic medium to a predetermined position as described above. It may have a shape.

Although the composite type thin film magnetic head of the present invention has been described by various embodiments, the present invention detects only the magnetic pole on the track on the magnetic medium by the MR head portion and does not detect the track side magnetic pole. Any structure may be used as long as it is configured as described above.

The magnetic head has been described above. However, if the magnetic medium is hard to be magnetized in the direction orthogonal to the track direction (orientated in the track direction), the fringing magnetic field can be further suppressed.

[0091]

As described in detail above, according to the present invention, the MR head unit is configured to detect only the magnetic poles on the tracks on the magnetic medium and not the track-side magnetic poles. The influence of the track / side magnetic poles on the magnetic medium generated by the fringing magnetic field of the inductive head during recording can be greatly reduced. As a result, the waveform distortion (base line transition noise = BLT noise) of the reproduced waveform is significantly reduced, and the peak shift of the reproduced waveform can be reduced.
The error rate can be improved.

[Brief description of drawings]

FIG. 1 is a bottom view schematically showing a composite type thin film magnetic head in the embodiment of FIG. 2 from the bottom side facing a magnetic medium.

FIG. 2 is a perspective view showing a flying type magnetic head unit including a composite type thin film magnetic head as one embodiment of the present invention.

FIG. 3 is a partial cross-sectional view taken along the line AA of FIG.

FIG. 4 is a diagram illustrating a magnetic field generated by an inductive head and a magnetic pole recorded on a magnetic medium by the magnetic field.

5 is a magnetic field generated by the inductive head of FIG. 4 when the recording current is further reversed and the recording current is reversed, the magnetic pole recorded on the magnetic medium by the head and the track are read by the MR head. It is a figure explaining the reproduction | regeneration waveform in the case.

FIG. 6 is a bottom view schematically showing a composite type thin film magnetic head according to another embodiment of the invention from the bottom side facing a magnetic medium.

FIG. 7 is a bottom view schematically showing a composite type thin film magnetic head in still another embodiment of the present invention from the bottom side facing a magnetic medium.

FIG. 8 is a bottom view schematically showing a composite type thin film magnetic head according to still another embodiment of the present invention from the bottom side facing the magnetic medium.

FIG. 9 is a bottom view schematically showing a composite type thin film magnetic head according to still another embodiment of the present invention from the bottom side facing a magnetic medium.

FIG. 10 is a bottom view schematically showing a composite type thin film magnetic head in still another embodiment of the present invention from the bottom surface side facing a magnetic medium.

FIG. 11 is a bottom view schematically showing a composite type thin film magnetic head according to still another embodiment of the present invention from the bottom side facing the magnetic medium.

12A and 12B schematically show a composite type thin film magnetic head according to still another embodiment of the present invention, FIG. 12A is a bottom view schematically showing the bottom surface side facing a magnetic medium, and FIG. It is the side view which looked at the MR element part from the track direction.

FIG. 13 is a bottom view schematically showing a conventional composite type thin film magnetic head from the bottom side facing a magnetic medium.

FIG. 14 is a diagram for explaining reproduced waveform distortion by a conventional composite type thin film magnetic head.

FIG. 15 is an actual reproduction waveform diagram by a conventional composite type thin film magnetic head.

[Explanation of symbols]

10, 710 MR head part 11, 711 Inductive head part 23, 123, 223, 323, 423, 523, 62
3,723 Ceramic structure 24,124,224,324,324,424,524,62
4,724 Base film 26, 126, 226, 326, 426, 526, 526, 62
6,726 Leads 30, 130, 230, 330, 430, 530, 63
0,730 Lower shield layer 33, 133, 233, 333, 433, 533, 63
3,733 Upper shield layer 31, 131, 231, 331, 431, 531, 63
1,731 MR elements 32a, 132a, 232a, 332a, 432a, 5
32a, 632a, 732a Lower gap insulating film 32b, 132b, 232b, 332b, 432b, 5
32b, 632b, 732b Upper gap insulating film 35, 135, 235, 335, 435, 535, 63
5,735 front magnetic layer 38, 138, 238, 338, 438, 538, 63
8,738 Rear magnetic layer 763 Shield material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazumasa Fukuda 1-13-1 Nihonbashi, Chuo-ku, Tokyo Tea Decay Co., Ltd. (72) Inventor Noboru Yamanaka 1-13-1 Nihonbashi, Chuo-ku, Tokyo DC Inc.

Claims (7)

[Claims] 1. A composite thin-film magnetic head having a reproducing magnetoresistive head portion and a recording inductive head portion formed on the magnetoresistive head portion.
A composite thin-film magnetic head, wherein the magnetoresistive head unit is configured to detect only magnetic poles on a track on a magnetic medium, and not detect track / side magnetic poles. 2. The effective head width of the magnetoresistive head portion is configured to be narrower than the effective head width of the inductive head portion so as to detect only the magnetic poles on the track. Composite thin film magnetic head. 3. The composite type thin film magnetic head according to claim 1, wherein the magnetoresistive head portion is shielded at a position corresponding to a lateral side of the track so as to detect only a magnetic pole on the track. 4. The core of the inductive head unit,
The magnetic head is composed of a front magnetic layer and a rear magnetic layer located on the front side and the rear side with respect to the relative traveling direction of the magnetic head with respect to the magnetic medium, and faces the magnetic medium of the front magnetic layer and the rear magnetic layer. 4. The composite thin film magnetic head according to claim 2, wherein at least the tip has a rectangular shape, and the width of the rear magnetic layer is shorter than the width of the front magnetic layer. 5. The core of the inductive head section,
The magnetic head is composed of a front magnetic layer and a rear magnetic layer located on the front side and the rear side with respect to the relative traveling direction of the magnetic head with respect to the magnetic medium, and faces the magnetic medium of the front magnetic layer and the rear magnetic layer. 4. The composite thin film magnetic head according to claim 2, wherein at least the tip has a rectangular shape, and the width of the rear magnetic layer is equal to or larger than the width of the front magnetic layer. 6. The core of the inductive head section,
The magnetic head is composed of a front magnetic layer and a rear magnetic layer located on the front side and the rear side with respect to the relative traveling direction with respect to the magnetic medium, and the shape of at least the tip of the rear magnetic layer facing the magnetic medium is at least 4. The composite thin film magnetic head according to claim 2, wherein the two side edges of the composite thin film magnetic head are inclined so that the width thereof becomes narrower toward the rear. 7. The core of the inductive head unit,
The magnetic head is composed of a front magnetic layer and a rear magnetic layer respectively located on the front side and the rear side with respect to the relative traveling direction of the magnetic medium, and the shape of at least the tip end of the front magnetic layer facing the magnetic medium is, 7. The composite thin-film magnetic head according to claim 2, wherein at least a rear portion of the side edge is formed so as to be inclined rearward so as to have a narrow width.