JPH1131311A - Shield type magneto-resistive effect thin film magnetic head and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cope with both improvement in an overwrite characteristic and the improvement in a servo characteristic. SOLUTION: A reproducing head 26 is constituted so that an MR element 24 is arranged on a position facing onto a recording medium opposite surface 16 in a reproducing gap 20 between a lower shield 18 and an upper shield 22. The upper shield 22 is shared as a lower core, and a coil 28 is arranged between the lower core 22 and an upper core 32, and a write-in gap 34 is formed between the upper pole 32a of the tip of the upper core 32 and the lower pole 22a of the tip of the lower core 22 on the position facing onto the recording medium opposite surface 16, and a recording head 36 is constituted. The upper shield- cum-lower core 22 is constituted of a thin plate part 22b formed in a thin planar shape on the position facing onto the record medium opposite surface 16 and a thick plate part 22c formed in a thick planar shape on the position secluded from the record medium opposite surface 16 succeeding to this thin plate part 22b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield type magnetoresistive thin-film magnetic head used in a hard disk drive or the like (a magnetic head using various magnetoresistive elements such as a GMR element in addition to an ordinary MR element). (Hereinafter referred to as “shield type MR head”), and write characteristics and rewrite (overwrite) for the magnetic recording medium.
The characteristics are improved and servo errors are less likely to occur.

[0002]

2. Description of the Related Art A shield type MR head used in a hard disk drive includes a reproducing head in which an MR element is disposed at a position facing a recording medium facing surface within a reproducing gap between a lower shield and an upper shield, and an upper shield. Is also used as a lower core, a coil is arranged between the lower core and the upper core, and a recording head having a write gap formed at a position facing the recording medium facing surface between the upper core and the lower core is laminated. Placed MR
It is configured as a combined type and induction type magnetic head.

Conventional shield type MR for hard disk
FIG. 2 is a sectional view of the center of the head. A nonmagnetic insulating layer 14 is coated on the substrate 12 constituting the slider. A lower shield 18 is embedded at a position facing the recording medium facing surface 16 above the non-magnetic insulating layer 14. On the lower shield 18, an upper shield 22 having a constant thickness is disposed so as to face the reproduction gap 20. An MR element 24 is embedded at a position facing the recording medium facing surface 16 in the reproduction gap 20. Leads (not shown) for flowing a sense current to the MR element 24 are connected to both left and right ends of the MR element 24. With the above, the reproducing head 2
1 (MR type head).

The upper shield 22 also serves as a writing lower core, and a coil 28 is disposed on the upper shield 22 so as to be embedded in an insulating layer 30. An upper core 32 is disposed on the insulating layer 30. The lower pole 22a of the tip of the upper shield and lower core 22 and the upper pole 32a of the tip of the upper core 32 face each other across the write gap 34 at a position facing the recording medium facing surface 16. Thus, the recording head 36 (induction type head) is configured. Then, the entirety of the shield type MR head 10 is formed by covering the entire surface with the protective film 38.

[0005]

In a shield type MR head, it is necessary to immediately read a written signal before the position is changed in order to perform servo of a track position. To do so, the write gap 34
It is necessary to shorten the interval Srw between the read gap 20 and the read gap 20.
That is, as the interval Srw becomes longer, servo errors are more likely to occur. In particular, servo errors are more likely to occur as the relative speed between the head and the magnetic recording medium, which can be accessed at high speed, is higher. This point will be described in more detail.

In a hard disk drive in which the shield type MR head 10 is mounted on a rotary type head positioner and is moved in the radial direction of the disk, a recording head 36 is provided.
The case where the signal written in step (1) is reproduced by the reproducing head 21 in the next round is considered. Recording head 36 and reproducing head 2
Assuming that 1 is tracing on the same track, this signal can be picked up by the reproducing head 21 immediately after completing one round of writing. However, the recording head 36
If the trace position of the read head 21 deviates from that of the read head 21, the written servo signal may not be immediately read.

That is, when positioning the shield type MR head 10 with a rotary type head positioner, a large skew angle (an angle in the center line direction of the shield type MR head 10 with respect to the track tangential direction) on the innermost side or the outermost side of the disk. If the shift occurs, the trace positions of the recording head 36 and the reproducing head 21 shift. At the same skew angle, as the distance Srw between the recording head 36 and the reproducing head 21 increases, the shift amount of the trace position increases. If the amount of deviation is small, the servo is immediately applied, so that the servo is applied after moving at most one track. However, if there is a deviation of one track or more, the operation shifts to an operation of searching for servo signals one by one. Assuming that the search operation is to search in the direction opposite to the target track position, the shield type MR head 10 moves to the inner side or outer side of the disk and continues to search until it returns again. Such an operation significantly reduces the access speed of writing and reading. In particular, a fatal response delay occurs in a model in which the access speed is increased by increasing the rotation speed of the disk.

Therefore, the fact that the reproducing head 21 is located at a position where the signal can be picked up immediately after one round of writing,
This is the most important thing to increase the access speed.
That is, the interval S between the recording head 36 and the reproducing head 21
The shorter rw, the better the high-speed access performance. Interval Srw
Is determined by the thickness of the upper shield and lower core 22,
In order to shorten the interval Srw, the upper shield and lower core 22 needs to be formed thin.

On the other hand, in order to perform high-density recording with a shield type MR head, it is necessary to increase the coercive force (Hc) of the magnetic recording medium. However, when the coercive force of the magnetic recording medium increases, a large magnetic flux leakage from the write gap 34 is required to write a signal to the magnetic recording medium (
When the amount of the leakage magnetic flux is not sufficient, the overwrite characteristics deteriorate and cause an error. ). Shield type MR
In the recording head 36, a magnetic flux leakage occurs between the upper and lower cores 32, 22 during writing. This leakage flux increases as the core thickness decreases as the magnetic resistance of the core increases, and the leakage flux from the write gap 34 decreases accordingly (see FIG. 3). Therefore, in order to improve the overwrite characteristics, it is necessary to increase the core thickness. In this case, the upper core 32 can be easily made thicker by stacking core layers, but the lower core 22 also serves as an upper shield.
, The interval Srw between the read gap 20 and the read gap 20 becomes longer, and the servo characteristics deteriorate.

As described above, in the conventional shield type MR head, it has not been possible to achieve both the improvement of the overwrite characteristic and the improvement of the servo characteristic.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art and to provide a shield type MR head which achieves both improvement of overwrite characteristics and improvement of servo characteristics, and a method of manufacturing the same.

[0012]

SUMMARY OF THE INVENTION A shield type M according to the present invention.
In the R head, the thickness of the upper shield and lower core is formed thinner at a position facing the recording medium facing surface and thicker at a position deeper than the recording medium facing surface. According to this, the thickness of the upper shield / write lower core is formed thinner at the position facing the recording medium facing surface, so that the interval between the write gap and the read gap can be shortened, thereby reducing the servo error. And the servo characteristics are improved. In addition, the thickness of the upper shield and lower core is increased at a position deeper than the recording medium facing surface, so that the increase in the magnetic resistance of the core can be suppressed, and the magnetic flux leakage between the upper and lower cores can be reduced. The leakage magnetic flux from the gap can be increased, and the overwrite characteristics are improved.

The upper shield / lower core of the shield type MR head according to the present invention has, for example, a thin plate-like thin plate portion formed at a portion exposed to the recording medium facing surface, and a thin plate portion formed at a portion recessed from the recording medium facing surface. Subsequently, a thick flat plate-shaped thick plate portion can be formed. In this case, when the step forming the boundary between the thin plate portion and the thick plate portion is close to the recording medium facing surface, the anisotropy energy due to the shape anisotropy of the upper shield and lower core is reduced by the write magnetic field. As a result, a magnetic domain division occurs, so that noise (Barkhausen noise) is generated particularly in the reproduced waveform when the mode is switched from the recording mode to the reproduction mode. Therefore, by forming the step at a distance of 10 μm or more from the surface facing the recording medium, magnetic domain division can be substantially prevented, and generation of noise when switching from the recording mode to the reproduction mode can be prevented.

Further, the track width direction of the thin plate portion is formed so as to be limited to the center portion of the entire width of the upper shield / lower core, and the thick plate portion is formed so as to surround the thin plate portion. The ratio of the area of the thick plate portion to the total area of the core can be increased, the increase in the magnetic resistance of the core can be further suppressed, and the leakage magnetic flux between the upper and lower cores can be further reduced. And the overwrite characteristic can be further improved.

The thin plate portion and the thick plate portion of the upper shield / upper core of the shield type MR head of the present invention are formed, for example, in a first step of forming a flat lower layer with the thickness of the thin plate portion, and on the lower layer portion. Forming a thick plate portion by laminating a plate-shaped upper layer portion at a position corresponding to a thickness difference between the thin plate portion and the thick plate portion at a position where the thick plate portion is to be formed. Can be. Alternatively, a first step of forming a flat lower layer portion at a position corresponding to the thickness of the thin plate portion at a position where the thick plate portion is to be formed, and forming the thin plate portion and the thick plate portion. And a second step of laminating the upper portion with the thickness of the thin plate portion over the entire position. Alternatively, a first step of forming a plate-like layer with the thickness of the thick plate portion over the entire position where the plate portion and the thick plate portion are formed, and a position where the thin plate portion of this layer is formed by the thin plate portion and the thick plate portion And a second step of forming a thin plate portion by digging in a thickness corresponding to the difference in thickness.

[0016]

Embodiments of the present invention will be described below. FIG. 1 shows a center sectional view of a shield type MR head 40 for a hard disk according to the present invention. The same reference numerals are used for the portions common to the conventional shield type MR head 10 of FIG.

A nonmagnetic insulating layer 14 is coated on the substrate 12 constituting the slider. The lower shield 1 is located at a position facing the recording medium facing surface 16 above the nonmagnetic insulating layer 14.
8 is embedded. On the lower shield 18, an upper shield 22 having a constant thickness is disposed so as to face the reproduction gap 20. An MR element 24 is embedded at a position facing the recording medium facing surface 16 in the reproduction gap 20.
Leads (not shown) for flowing a sense current to the MR element 24 are connected to both left and right ends of the MR element 24. Thus, the reproducing head 21 (MR type head) is configured.

The upper shield 22 also serves as a writing lower core, and the coil 28 is disposed thereon with the coil 28 embedded in the insulating layer 30. An upper core 32 is disposed on the insulating layer 30. The lower pole 22a of the tip of the upper shield and lower core 22 and the upper pole 32a of the tip of the upper core 32 face each other across the write gap 34 at a position facing the recording medium facing surface 16. Thus, the recording head 36 (induction type head) is configured. Then, the entirety of the shield type MR head 10 is formed by covering the entire surface with the protective film 38.

The upper shield / lower core 22 has a thin plate portion 22 formed in a thin plate shape at a position facing the recording medium facing surface 16.
b, and a thick plate portion 22c formed into a thick flat plate at a position recessed from the recording medium facing surface 16 following the thin plate portion 22b. On the upper surface of the upper shield / lower core 22, a step 22d is formed at the boundary between the thin plate portion 22b and the thick plate portion 22c. The lower surface of the upper shield and lower core 22 is flat. The distance from the recording medium facing surface 16 to the step portion 22d (that is, the length of the thin plate portion 22b in the depth direction) is set to 10 μm or more.
2 can be substantially prevented from being set.

According to the structure of the upper shield / lower core 22, the thin plate portion 22 is located at a position facing the recording medium facing surface 16.
b, the write gap 34 and the read gap 2
The interval Srw of 0 can be shortened, and the servo error can be reduced. Further, since the thick plate portion 22c is formed at a position deeper than the recording medium facing surface 16, the magnetic resistance of the upper shield and lower core 22 is reduced, and the upper and lower cores 32,
Leakage magnetic flux between the magnetic heads 22 can be reduced, thereby increasing the magnetic flux leakage from the write gap 34 and improving the overwrite characteristics.

Here, the conventional shield type MR head 10 of FIG. 2 and the shield type MR head 4 of the present invention of FIG.
The overwrite characteristics of 0 are compared. FIG. 4 shows the measurement results of the thickness dependence of the upper shield / lower core 22 of the overwrite characteristic in the conventional shield type MR head 10. Shield type MR head 10 used for measurement
The dimensions of each part are shown in FIG. FIG. 6 shows a measurement result of the dependence of the overwrite characteristic on the thickness of the upper shield / lower core 22 in the shield type MR head 40 according to the present invention. FIG. 7 shows dimensions of each part of the shield type MR head 40 used for the measurement. In FIG. 7, the difference between the thickness of the thin plate portion 22b and the thick plate portion 22c of the upper shield / lower core 22 (the height of the step portion 22d) is 0.2 μm, and the length of the thin plate portion 22b in the depth direction (the recording medium facing surface). The length of the MR element 24 in the depth direction is 1 to 20 μm.
2 μm. The interval Srw between the write gap 34 and the reproduction gap 20 is: Srw = thickness of thin plate portion 22b + (write gap length + reproduction gap length) / 2.

4 and 6, the upper shield / lower core 22 of the shield type MR head 40 according to the present invention is formed with the thick plate portion 22c to reduce the magnetic resistance. In spite of the fact that the interval of the reproducing gap 20 is the same as that of the conventional shield type MR head 10, the leakage magnetic flux between the upper and lower cores 32, 22 is small, and a large leakage magnetic flux is effectively generated in the write gap 34 with a small write current. As a result, the overwrite characteristics are significantly improved.

FIG. 8 shows a measurement result of the write current dependency of the overwrite characteristic in the conventional shield type MR head 10 of FIG. FIG. 9 shows a measurement result of the write current dependence of the overwrite characteristic in the shield type MR head 40 according to the present invention of FIG. The interval Srw between the write gap 34 and the reproduction gap 20 is set equal for both heads 10 and 40. According to this, in the case of the conventional shield type MR head 10, when the holding power Hc of the magnetic disk is 2000 Oe, the write current is 30 m.
At A, the overwrite characteristics are saturated, but Hc = 250.
At 0 Oe, it is not saturated even at 50 mA. The overwrite value at a write current of 30 mA is as low as about 30 dB.
On the other hand, in the shield type MR head 40 according to the present invention shown in FIG. 1, even at Hc = 2500 Oe, it is saturated at about 30 mA. The overwrite value is as high as about 39 dB.

As described above, by increasing the thickness of the rear end in the depth direction without changing the thickness (lower pole length) of the tip of the pole of the upper shield / lower core 22, the write gap 34 and the reproduction gap 20 are formed. Overwrite characteristics can be greatly improved without increasing the interval Srw. In addition, even if the lower pole length is slightly shortened, the overwrite value does not significantly decrease, so that the yield is less likely to decrease due to variations in the lower pole length. Further, since it has an excellent writing capability even for a magnetic recording medium having a high coercive force Hc for a high recording density, a hard disk device having a high recording density can be realized.

The thin plate portion 22b of the shield type MR head 40 shown in FIG. 1 can extend over the entire width of the upper shield / lower core 22 in the track width direction, or can be formed only on a part of the track width direction. it can. FIGS. 10A and 10B show examples of the planar shapes of the upper and lower cores 32 and 22 and the end surface shapes of the upper and lower poles 32a and 22a when formed only in a part of the track width direction. The track width direction of the thin plate portion 22b is formed to be limited to the central portion of the entire width of the upper shield and lower core 22, and the thick plate portion 22c is formed by the thin plate portion 22b.
Is formed so as to surround the three sides (step 22d).
Are also formed so as to surround the thin plate portion 22b from three sides. ). Therefore, when viewed from the end face of the pole, the thin plate portion 22b forms a recess 42 that opens upward as shown in FIG. 10B. In the recess 42, the upper pole 32a is accommodated and arranged at the center in the track width direction.

According to the structure of the upper shield / lower core 22 as shown in FIG. 10, a large area of the thick plate portion 22c can be secured, so that an increase in the magnetic resistance of the upper shield / lower core 22 can be further suppressed. , The leakage magnetic flux between the upper and lower cores 32 and 22 can be further reduced.
And the overwrite characteristics can be further improved. By forming the length of the thin plate portion 22b in the track width direction to be at least 20 times the length of the upper pole 32a in the track width direction, the magnetic domain of the upper shield / lower core 22 at the step portion 22d due to the write magnetic field is formed. Splitting can be substantially prevented.

Next, a method of manufacturing the shield type MR head 40 shown in FIG. 1 will be described. FIG. 11 shows various methods for making the upper shield / lower core 22. FIG.
(A) shows the thickness of the thin plate portion 22b and the flat lower layer portion 22-.
1 at the position where the thick plate portion 22c is to be formed on the lower layer portion 22-1 at a position corresponding to the difference in thickness between the thin plate portion 22b and the thick plate portion 22c (eg, 2 μm). -2 is formed by forming a thick plate portion 22c by raising the laminate.

FIG. 11B shows a flat lower layer portion 22-11 having a thickness (2 μm or the like) corresponding to the difference in thickness between the thin plate portion 22b and the thick plate portion 22c at the position where the thick plate portion 22c is formed. And the upper portion 22-12 is laminated with the thickness of the thin plate portion 22b over the entire position where the thin plate portion 22b and the thick plate portion 22c are formed.

FIG. 11C shows the thin plate portion 22 b and the thick plate portion 2.
A plate-like layer 22 'is formed with the thickness of the thick plate portion 22c over the entire position where the 2c is formed, and the thin plate portion 22 of this layer 22' is formed.
The position where b is formed is dug by a thickness (eg, 2 μm) corresponding to the thickness difference between the thin plate portion 22b and the thick plate portion 22c (digging 44) to form the thin plate portion 22b.

[Manufacturing process of the structure of FIG. 11A] FIG.
An example of a manufacturing process of the shield type MR head 40 having the structure shown in FIG. 12A is shown in FIGS. 12 to 15 by processes (1) to (14). Each step will be described. (1) A nonmagnetic insulating layer 14 such as Al ₂ O ₃ (alumina) is formed on a substrate 12 made of Al ₂ O ₃ —TiC (altic) or the like, and a nonmagnetic insulating layer 14 such as NiFe is plated thereon. A base film 46 is formed. A frame 48 for forming the lower shield 18 is formed of a resist on the plating base film 46. (2) A soft magnetic material such as NiFe is electroplated to form the lower shield 18 on the plating base film 46 to form a plating film 50. After forming the plating film 50, the frame resist 48 is removed. A concave portion 52 is formed in a portion where the frame resist 48 is removed.

(3) The whole is subjected to ion milling to remove the plating base film 46 exposed at the bottom of the concave portion 52. (4) A portion of the plating film 50 to be left as the lower shield 18 is covered with a protective resist 56. (5) Exposed portions of the plating film 50 are removed by etching. After the etching, the protective resist 56 is removed. (6) A protective film 58 such as Al ₂ O ₃ is deposited on the entire surface by sputtering or the like. (7) The surface is polished and flattened. Polishing is plating film 5
0 is performed until the thickness of the lower shield 18 becomes a specified thickness.
Thus, the lower shield 18 is completed.

(8) To form the reproducing gap 20, Al ₂ O ₃ or the like is deposited to a half of a specified thickness of the reproducing gap layer 60, and a lead film is laminated thereon and cut into a predetermined lead pattern. I do. Further, an MR element film is laminated and cut into a predetermined MR element pattern to form an MR element 24. The other half of the reproducing gap layer 60 is deposited thereon, thereby completing the reproducing gap layer 60 with the MR element 24 and the lead interposed therebetween.

(9) A plating underlayer is formed on the entire pattern of the upper shield / lower core 22 with a soft magnetic material such as NiFe, and a soft magnetic material such as NiFe is formed on the thin plate portion of the upper shield / lower core 22 thereon. Electroplating to a thickness of 22b and lower part 2
2-1 is formed. (10) The portion forming the thin plate portion 22b is covered with a frame resist, and a soft magnetic material such as NiFe is electroplated by an amount corresponding to the difference in thickness between the thin plate portion 22b and the thick plate portion 22c. Form 2 This is the upper shield and lower core 2
2 is completed.

(11) A write gap layer 62 such as Al ₂ O ₃ is deposited to form the write gap 34. (12) After cutting the rear portion of the write gap layer 62, the coil 28 and the insulating layer are alternately laminated to form the coil 28 in the insulating layer 30. (13) An underlayer is formed of a soft magnetic material such as NiFe in a pattern of the upper core 32, and a soft magnetic material such as NiFe is electroplated thereon to form the upper core 32.

(14) Finally, a protective film 38 of Al ₂ O ₃ or the like
To complete.

[Manufacturing process of the structure of FIG. 11B]
One example of the manufacturing process of the shield type MR head 40 having the structure shown in FIG. 16B is shown in FIGS. 16 to 17 by processes (9) to (14). Steps (1) to (8) are the same as steps (1) to (8) in FIGS. Step (9)
(14) will be described.

(9) On the read gap layer 60, the thin plate portion 22b of the entire pattern of the upper shield and lower core 22
A soft magnetic material such as NiFe is
The lower portion 22-11 is formed by electroplating to a thickness corresponding to the difference between the thickness of 2b and the thickness of the thick plate portion 22c.

(10) In the entire pattern of the upper shield / lower core 22, a soft magnetic material such as NiFe is electroplated with a thickness of the thin plate portion 22b to form an upper layer portion 22-12.
The upper shield and lower core 22 is completed.

(11) A write gap layer 62 such as Al ₂ O ₃ is deposited to form the write gap 34. (12) After cutting the rear part of the write gap layer 62, the coil 28 is formed in the insulating layer 30. (13) An underlayer is formed of a soft magnetic material such as NiFe in a pattern of the upper core 32, and a soft magnetic material such as NiFe is electroplated thereon to form the upper core 32.

(14) Finally, a protective film 38 of Al ₂ O ₃ or the like
To complete.

[Manufacturing process of the structure of FIG. 11C] FIG.
An example of the manufacturing process of the shield type MR head 40 having the structure of FIG. 18C is shown in FIGS. 18 to 19 by processes (9) to (16). Steps (1) to (8) are the same as steps (1) to (8) in FIGS. Step (9)
(16) will be described.

(9) A soft magnetic material such as NiFe is electroplated on the reproducing gap layer 60 with the entire pattern of the upper shield / lower core 22 to a thickness of the thick plate portion 22c.
Form 2 '. (10) A resist pattern for digging is formed leaving a position where the thin plate portion 22b is formed.

(11) The whole is ion-milled to form a layer 2
The exposed portion 2 ′ is connected to the thin plate portion 22b and the thick plate portion 22.
Excavate by the amount corresponding to the thickness difference of c. (12) When the resist pattern 64 is removed after the formation of the digging 44, the upper shield / lower core 22 having the thin plate portion 22b and the thick plate portion 22c is completed.

(13) Al constituting the write gap 34
A write gap layer 62 such as ₂ O ₃ is deposited. (14) After cutting the rear part of the write gap layer 62, the coil 28 is formed in the insulating layer 30. (15) A plating underlayer is formed of a soft magnetic material such as NiFe in a pattern of the upper core 32, and a soft magnetic material such as NiFe is electroplated thereon to form the upper core 32.

(16) Finally, a protective film 38 of Al ₂ O ₃ or the like
To complete.

[Brief description of the drawings]

FIG. 1 shows a shield type MR showing an embodiment of the present invention.
FIG. 3 is a sectional view taken along a center line of the head.

FIG. 2 is a sectional view taken along a center line of a conventional shield type MR head.

FIG. 3 is a diagram showing a difference in magnetic flux due to a write current when the thickness of an upper shield and lower core is thin and thick in a conventional shield type MR head.

FIG. 4 is a characteristic diagram showing the thickness dependence of an upper shield / lower core of overwrite characteristics in a conventional shield type MR head.

FIG. 5 shows a conventional shield type MR measuring the characteristics of FIG.
FIG. 3 is a diagram illustrating dimensions of each part of a head.

FIG. 6 is a characteristic diagram showing the dependence of the overwrite characteristic on the thickness of the upper shield and lower core in the shield type MR head according to the present invention of FIG. 1;

7 shows the shield type MR of FIG. 1 obtained by measuring the characteristics of FIG.
FIG. 3 is a diagram illustrating dimensions of each part of a head.

8 is a characteristic diagram showing a write current dependency of an overwrite characteristic in the conventional shield type MR head of FIG.

9 is a characteristic diagram showing a write current dependency of an overwrite characteristic in the shielded MR head of the present invention in FIG. 7;

FIG. 10 is a diagram showing an example of a planar shape and a pole front shape of upper and lower cores in the shield type MR head of FIG. 1;

FIG. 11 is a view showing a difference in structure of the shield type MR head of FIG. 1 by various manufacturing methods of an upper shield and a lower core.

FIG. 12 is a sectional view taken along a center line showing an example of a manufacturing process of the structure of FIG. 11A.

FIG. 13 is a process drawing showing a continuation of FIG. 12;

FIG. 14 is a process drawing showing a continuation of FIG. 13;

FIG. 15 is a process drawing showing a continuation of FIG. 14;

FIG. 16 is a cross-sectional view taken along a center line showing an example of a manufacturing process of the structure of FIG. 11B, and is a process drawing continued from FIG.

FIG. 17 is a process drawing showing a continuation of FIG. 16;

FIG. 18 is a cross-sectional view taken along a center line showing an example of a manufacturing process of the structure of FIG. 11C, and is a process drawing continued from FIG.

FIG. 19 is a process drawing illustrating a sequel to FIG. 18;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 16 Recording medium facing surface 18 Lower shield 20 Reproducing gap 21 Reproducing head 22 Upper shield and lower core 22a Lower pole 22b Thin plate portion 22c Thick plate portion 22d Step portion 22-1, 22-11 Lower layer portion 22-2, 22-12 Upper part 22 'layer 24 MR element 26 Reproducing head 28 Coil 32 Upper core 32a Upper pole 34 Write gap 36 Recording head 40 Shield type MR head (shield type magnetoresistive thin film magnetic head) 44 Digging

Claims (8)

[Claims] A reproducing head in which an MR element is arranged at a position facing a recording medium facing surface in a reproducing gap between a lower shield and an upper shield; and the lower core and the upper core using the upper shield as a lower core. A recording head having a coil disposed between the core and a write gap formed between an upper pole of the tip of the upper core and a lower pole of the tip of the lower core at a position facing the recording medium facing surface; In the shield type magnetoresistive thin-film magnetic head, the thickness of the upper shield / lower core is formed thin at a position facing the recording medium facing surface and thick at a position recessed from the recording medium facing surface. Shielded magnetoresistive thin film magnetic head. 2. A reproducing head in which an MR element is arranged at a position facing a recording medium facing surface in a reproducing gap between a lower shield and an upper shield, and the lower core and the upper core using the upper shield as a lower core. A recording head having a coil disposed between the core and a write gap formed between an upper pole of the tip of the upper core and a lower pole of the tip of the lower core at a position facing the recording medium facing surface; Wherein the upper shield and lower core are formed in a thin plate shape at a position facing the recording medium facing surface, and the recording medium follows the thin plate portion. A shield-type magnetoresistive thin-film magnetic head comprising: a thick plate portion formed in a thick flat shape at a position recessed from an opposing surface. 3. A step forming a boundary between the thin plate portion and the thick plate portion, the step portion having a depth of 10 μm in a depth direction from the recording medium facing surface.
3. The shielded magnetoresistive thin-film magnetic head according to claim 2, wherein said shielded magnetoresistive thin-film magnetic head is formed at a position separated by at least m. 4. The thin plate portion is formed such that a track width direction is limited to a central portion of the entire width of the upper shield and lower core,
4. A shield type magnetoresistive thin film magnetic head according to claim 2, wherein said thick plate portion is formed so as to surround said thin plate portion. 5. A length of the thin plate portion in a track width direction at a position exposed to the recording medium facing surface is formed to be at least 20 times a length of the upper pole in a track width direction. The shield-type magnetoresistive thin-film magnetic head as described in the above. 6. A method of manufacturing a shielded magnetoresistive thin-film magnetic head according to claim 2, wherein the step of forming the upper shield and lower core comprises the step of: A first step of forming a plate-shaped lower layer portion at a position where the thick plate portion is formed on the lower layer portion, with a thickness corresponding to a difference between the thickness of the thin plate portion and the thickness of the thick plate portion. A second step of forming the thick plate portion by laminating the upper layer portion of the shield type magnetoresistive thin film magnetic head. 7. A method of manufacturing a shielded magnetoresistive thin-film magnetic head according to claim 2, wherein said step of forming said upper shield and lower core includes forming said thick plate portion. A first step of forming a flat lower layer portion at a position corresponding to the thickness difference between the thin plate portion and the thick plate portion, and over the entire position where the thin plate portion and the thick plate portion are formed. And a second step of laminating an upper layer portion with the thickness of the thin plate portion. 8. A method of manufacturing a shield type magnetoresistive thin film magnetic head according to claim 2, wherein said step of forming said upper shield and lower core comprises the step of forming said thin plate portion and said thickness. A first step of forming a flat layer with the thickness of the thick plate portion over the entire position where the plate portion is formed, and the position of the layer where the thin plate portion is formed is determined by the thickness of the thin plate portion and the thickness of the thick plate portion. A second step of forming the thin plate portion by digging a thickness corresponding to the difference in height.