SHINGLE MAGNETIC WRITER HAVING NONCONFORMAL SHIELDS
A shingle magnetic write apparatus is described. The shingle magnetic write apparatus includes a pole, a side gap, a write gap, a top shield and side shield(s). The pole has a pole tip region including a top wider than a bottom, and sides. The sides are at a sidewall angle from a down track direction. The write gap is adjacent to the pole top and between the top shield and the pole top. The side shield(s) are magnetically connected with the top shield and extend past the bottom of the pole. The side gap is between the side shield(s) and the pole. The side shield(s) have pole-facing surface(s) not more than a side shield angle from the down track direction. The side shield angle is less than the sidewall angle. The side gap width increases from the top near the gap to the bottom near the bottom of the pole.
In order to record data at higher areal densities, shingle magnetic recording may be used.
Although the conventional magnetic recording system 10 functions for shingle magnetic recording, there are drawbacks. In particular, the pole 20 may have stringent requirements for the track edge and reduced track curvature. Thus, side shields (not shown) separated from the pole 20 by small side gaps may be required. Issues such as wide area track erasure degradation, the concentration of magnetic flux at the side shields, write field loss due to the small side gap, and increased rise time may also adversely affect performance of the conventional magnetic recording system 20. Accordingly, what is needed is a system and method for improving the performance of a magnetic recording head, particularly for shingle magnetic recording.
While the various embodiments disclosed are applicable to a variety of data storage devices such as magnetic recording disk drives, solid-state hybrid disk drives, networked storage systems, for the purposes of illustration the description below uses disk drives as examples.
The disk drive 100 includes a media 102, and a slider 110 on which a transducer 120 has been fabricated. Although not shown, the slider 110 and thus the transducer 120 are generally attached to a suspension. In general, the slider 110 includes the write transducer 120 and a read transducer (not shown). However, for clarity, only the write transducer 120 is shown.
The transducer 120 includes coil(s) 122, a pole 130, optional bottom shield 140, side shields 150, top shield 160, write gap 170, side gap 180 and bottom gap 190. The pole 130 is magnetic and may have a high saturation magnetization greater than 2.0 T. The pole 130 has a pole tip region including bottom and a top wider than the bottom. A portion of the pole tip 130 occupies the ABS and is shown in
In the embodiment shown, a top shield 160 is separated from the pole 130 by the write gap 170. The side shields 150 are separated from the sidewalls of the pole 130 by side gaps 180. The bottom shield 140 is separated from the bottom of the pole 130 by a bottom gap 190. In embodiments in which the bottom shield 140 is omitted, the bottom gap 190 may separate the bottom of the pole tip 130 from underlying structures. The gaps 170, 180 and 190 are nonmagnetic. At least some of the gaps 170, 180 and 190 include nonmagnetic insulators. However, other materials may be used.
The side shields 150 are magnetically connected with the top shield 160 and extend past the bottom of the pole tip 130 by a distance, h. h is nonzero and substantially the height of the bottom gap 190 in the case where a bottom shield 140 is present. The side gap 180 is between the side shields 150 and the pole tip 130.
The side shields 150 have pole-facing surfaces 152 oriented at a side shield angle, β, from the down track direction. The side shield angle is less than the sidewall angle (β<α). The side shield angle is such that the spacing between the side shields at the bottom shield 140 is larger than at the top shield 160. Note that if the side shield angle was the same as the sidewall angle α, the spacing between the side shields 150 would be the same at the top shield 160 and bottom shield 140. Thus, the side shields 150 are not conformal with the pole 130 and are configured such that the bottom of the side shields 150 are further from the pole 130 than the top of the side shields 150. In some embodiments, the side shield angle is not more than one-half of the sidewall angle (β≦α/2). Thus, the width of the side gap 180 monotonically increases (increases without decreasing) from the top of the pole tip 130 toward the bottom of the pole top 130. In some such embodiments, the side shield angle is not more than one-third of the sidewall angle (β≦α/3). Thus, in some embodiments, the side shield angle is not more than five degrees from the down track direction. In some such embodiments, the side shield angle is not less than two degrees from the down track direction (2 degrees≦β≦5 degrees). Thus, the pole-facing surfaces 152 are close to or at vertical (close to or at parallel to the down track direction). Although the side shield angle is shown in a particular direction from the down track direction in
Because of the relationship between the sidewall angle, a, and the side shield angle, β, the side gap 180 has a varying width. Near the top of the pole tip 130, the side gap 180 has a width, w1. The width increases to a width w2. At the bottom of the pole tip 130, the width is the largest w3 (w1≦w2≦w3). Further, the side gap at the trailing edge (top) may be thin. In some embodiments, w1 is not more than one and one half multiplied by the thickness of the write gap 170. The side gap width w1 may be not more than forty nanometers. In the embodiment shown, w1 may be at least fifteen nanometers and not more than thirty-five nanometers. In some such embodiments, the side gap 180 is not larger than twenty-five nanometers at its top (w1≦25 nm). In addition to the increasing size of the side gaps 180 towards the bottom of the pole tip 130, the bottom gap 190 is larger than the bottom of the side gap (w3<h). In some embodiments, h is on the order of one hundred nanometers. Because of the geometry of the pole 130 and side shields 150, the side gap remains thin near the top of the pole tip 130/write gap 170. This is the region at which the transducer 120 writes to the media 102. Thus, the small side gap 180 for writing, which is desirable for shingle magnetic recording, is preserved.
The disk drive 100 may have improved performance in shingle magnetic recording. The configuration of the pole 130 and side shields 150 may enhance shingle writing. For example, a small side gap (w1) at the trailing edge (top) of the pole 130 may improve track edge writing and erasing. Thus, writer flux leakage may be mitigated. Use of the bottom (leading) shield 140 may reduce flux shunting, thereby improving writeability. Wide area track erasure (WATER) may also be improved. The field rise time, data rate and field gradient may also be improved. Performance of the disk drive 100 may thus be improved.
The pole 130 has a pole tip region including bottom and a top wider than the bottom and which may occupy part of the ABS as shown in
The side shields 150′ have pole-facing surfaces 152′ oriented at a side shield angle, β, from the down track direction. The side shield angle is less than the sidewall angle (β<α). The side shields 150′ are not conformal with the pole 130. The bottom of the side shields 150′ are further from the pole 130 than the top of the side shields 150′. For the side shields 150′, the sidewall angle is in the opposite direction from the down track direction than for the side shields 150. Thus, the spacing between the side shields 150′ at the bottom shield is greater than at the top shield. The relationship between the sidewall angle and the side shield angle may be the same for the transducer 120′ as for the transducer 120. For example, in some embodiments, the side shield angle is not more than one-half of the sidewall angle (β≦α/2). The width of the side gap 180′ may also monotonically increase from the top of the pole tip 130 toward the bottom of the pole top 130. In some such embodiments, the side shield angle is not less than two degrees from the down track direction (2 degrees≦β≦5 degrees). Thus, the pole-facing surfaces 152′ are close to or at vertical (close to or at parallel to the down track direction). The side shields 150′ are also magnetically coupled with the top shield 160.
Because of the relationship between the sidewall angle, a, and the side shield angle, β, the side gap 180 has a varying width. Near the top of the pole tip 130, the side gap 180 has a width, w1′ which may be almost the same as the width w1 in
The disk drive 100′ may share the benefits of the disk drive 100. The configuration of the pole 130 and side shields 150′ may improve track edge writing and erasing, may reduce writer flux leakage, may reduce flux shunting, may thereby improving writeability and improve WATER. The field rise time, data rate and field gradient may also be improved. Performance of the disk drive 100′ may thus be improved for shingle recording.
The disk drive 100″ may be a PMR disk drive. However, in other embodiments, the disk drive 100″ may be configured for other types of magnetic recording. The disk drive 100″ may also use a shingle magnetic recording scheme. However, in other embodiments, other recording schemes may be used. The disk drive 100″ typically includes the write transducer 120″ and a read transducer. However, only the write transducer 120″ is depicted. The disk drive 100″ and transducer 120″ correspond to the disk drives 100/100′ and transducer 120/120′, respectively. Consequently, analogous components are labeled similarly. For example, the transducer 120″ includes a write pole 130, bottom shield 140, side shields 150″, top shield 160, write gap 170, side gap 180″ and bottom gap 190. The structure and function of the components 130, 140, 150″, 160, 170, 180″ and 190 are analogous to those of the components 130, 140, 150/150′, 160, 170, 180/180′ and 190, respectively, of the write transducer 120/120′.
The pole 130 has a pole tip region including bottom and a top wider than the bottom. Thus, the sides of the pole tip 130 are at a sidewall angle, a, from a down track direction. In the embodiment shown, the bottom of pole tip is an edge. Thus, the pole tip 130 forms a triangle at the ABS. Other shapes are possible having a top wider than the bottom are possible. In some embodiments, the sidewall angle is at least twelve degrees and not more than fifteen degrees. In other embodiments, the sidewall angle is at least four degrees and not more than nine degrees. Other sidewall angles are possible.
The side shields 150″ have pole-facing surfaces 152″ oriented at a side shield angle, β, from the down track direction. In the embodiment shown in
Because of the relationship between the sidewall angle, a, and the side shield angle, β, the side gap 180″ has a varying width. Near the top of the pole tip 130, the side gap 180 has a width, w1″ which may be almost the same as the width w1 in
The disk drive 100″ may share the benefits of the disk drive(s) 100 and 100′. The configuration of the pole 130 and side shields 150″ may improve track edge writing and erasing, may reduce writer flux leakage, may reduce flux shunting, may thereby improving writeability and improve WATER. The field rise time, data rate and field gradient may also be improved. Performance of the disk drive 100′ may thus be improved for shingle recording.
The disk drive 100′″ may be a PMR disk drive. However, in other embodiments, the disk drive 100′″ may be configured for other types of magnetic recording. The disk drive 100′″ may also use a shingle magnetic recording scheme. However, in other embodiments, other recording schemes may be used. The disk drive 100′″ typically includes the write transducer 120′″ and a read transducer. However, only the write transducer 120′″ is depicted. The disk drive 100′″ and transducer 120′″ correspond to the disk drives 100/100′/100″ and transducer 120/120′/120″, respectively. Consequently, analogous components are labeled similarly. For example, the transducer 120′″ includes a write pole 130, bottom shield 140, side shields 150″, top shield 160, write gap 170′, side gap 180″ and bottom gap 190. The structure and function of the components 130, 140, 150″, 160, 170, 180″ and 190 are analogous to those of the components 130, 140, 150/150′, 160, 170, 180/180′ and 190, respectively, of the write transducer 120/120′/120″.
The pole 130 has a pole tip region including bottom and a top wider than the bottom. Thus, the sides of the pole tip 130 are at a sidewall angle, a, from a down track direction. In the embodiment shown, the bottom of pole tip is an edge. Thus, the pole tip 130 forms a triangle at the ABS. Other shapes are possible having a top wider than the bottom are possible. In some embodiments, the sidewall angle is at least twelve degrees and not more than fifteen degrees. In other embodiments, the sidewall angle is at least four degrees and not more than nine degrees. Other sidewall angles are possible.
The side shields 150′″ have pole-facing surfaces 152′″. In the embodiment shown, the pole-facing surfaces 152′″ are in the down track direction (vertical as seen in
In addition, the write gap 170′, side shields 150′″ and top shield 160 are configured such that the write gap 170′ has an overhang of length t. In some embodiments, the overhang may be small, for example at least twenty nanometers and not more than forty nanometers. In other embodiments, the overhang may be large. For example, the overhang may be at least ninety nanometers and not more than one hundred twenty nanometers. However, other sizes for the overhang are possible.
Because of the relationship between the sidewall angle, a, and the side shield angle, β, the side gap 180″ has a varying width. Near the top of the pole tip 130, the side gap 180 has a width, w1″ which may be almost the same as the width w1 in
The disk drive 100′″ may share the benefits of the disk drive(s) 100, 100′ and 100″. The configuration of the pole 130 and side shields 150′″ may improve track edge writing and erasing, may reduce writer flux leakage, may reduce flux shunting, may thereby improving writeability and improve WATER. The field rise time, data rate and field gradient may also be improved. Performance of the disk drive 100′ may thus be improved for shingle recording.
The transducer 220 is most analogous to the transducer 120 depicted in
In lieu of a bottom shield, the side shields 250 extend past the bottom of the pole tip 230. In some embodiments, the side shields 250 extend past the bottom of the pole tip 230 by a distance, I, that is at least twice the pole tip height at the ABS and not more than five times the pole tip height at the ABS. In some embodiments, the height of the pole tip 230 is ninety nanometers and the side shields 250 extend past the bottom of the pole tip 230 at the ABS by at least three hundred nanometers and not more than four hundred nanometers.
The disk drive 200 may share the benefits of the disk drives 100, 100′, 100″ and/or 100′″. The configuration of the pole 230 and side shields 250 may improve track edge writing and erasing, may reduce writer flux leakage, may reduce flux shunting, may thereby improving writeability and improve WATER. The field rise time, data rate and field gradient may also be improved. Performance of the disk drive 200 may thus be improved for shingle recording. In the disk drive 200, one or more of these benefits may be realized even though the transducer 220 does not include a bottom shield. Instead, the side shield 250 extend a sufficient distance in the down track direction below the bottom of the pole tip 230 that the benefit(s) described herein may be realized.
The transducer 220′ is most analogous to the transducers 120′ and 220 depicted in
In lieu of a bottom shield, the side shields 250′ extend past the bottom of the pole tip 230. In some embodiments, the side shields 250′ extend past the bottom of the pole tip 230 by a distance, I, that is at least twice the pole tip height at the ABS and not more than five times the pole tip height at the ABS. In some embodiments, the height of the pole tip 230 is ninety nanometers and the side shields 250′ extend past the bottom of the pole tip 230 at the ABS by at least three hundred nanometers and not more than four hundred nanometers.
The disk drive 200′ may share the benefits of the disk drives 100, 100′, 100″, 100′″ and/or 200. The configuration of the pole 230 and side shields 250′ may improve track edge writing and erasing, may reduce writer flux leakage, may reduce flux shunting, may thereby improving writeability and improve WATER. The field rise time, data rate and field gradient may also be improved. Performance of the disk drive 200′ may thus be improved for shingle recording. In the disk drive 200′, one or more of these benefits may be realized even though the transducer 220′ does not include a bottom shield.
The transducer 220″ is most analogous to the transducers 120″, 220 and 220′ depicted in
In lieu of a bottom shield, the side shields 250″ extend past the bottom of the pole tip 230. In some embodiments, the side shields 250″ extend past the bottom of the pole tip 230 by a distance, I, that is at least twice the pole tip height at the ABS and not more than five times the pole tip height at the ABS. In some embodiments, the height of the pole tip 230 is ninety nanometers and the side shields 250″ extend past the bottom of the pole tip 230 at the ABS by at least three hundred nanometers and not more than four hundred nanometers.
The disk drive 200″ may share the benefits of the disk drives 100, 100′, 100″, 100′″, 200 and/or 200′. The configuration of the pole 230 and side shields 250″ may improve track edge writing and erasing, may reduce writer flux leakage, may reduce flux shunting, may thereby improving writeability and improve WATER. The field rise time, data rate and field gradient may also be improved. Performance of the disk drive 200″ may thus be improved for shingle recording. In the disk drive 200″, one or more of these benefits may be realized even though the transducer 220″ does not include a bottom shield.
The transducer 220′″ is most analogous to the transducers 120′″, 220, 220′ and 220″ depicted in
In lieu of a bottom shield, the side shields 250′″ extend past the bottom of the pole tip 230. In some embodiments, the side shields 250′″ extend past the bottom of the pole tip 230 by a distance, I, that is at least twice the pole tip height at the ABS and not more than five times the pole tip height at the ABS. In some embodiments, the height of the pole tip 230 is ninety nanometers and the side shields 250′″ extend past the bottom of the pole tip 230 at the ABS by at least three hundred nanometers and not more than four hundred nanometers.
The disk drive 200′″ may share the benefits of the disk drives 100, 100′, 100″, 100′″, 200, 200′ and/or 200″. The configuration of the pole 230 and side shields 250′″ may improve track edge writing and erasing, may reduce writer flux leakage, may reduce flux shunting, may thereby improving writeability and improve WATER. The field rise time, data rate and field gradient may also be improved. Performance of the disk drive 200′″ may thus be improved for shingle recording. In the disk drive 200′″, one or more of these benefits may be realized even though the transducer 220′″ does not include a bottom shield.
Various configurations of the disk drives 100, 100′, 100″, 100′″, 200, 200′, 200″ and 200′″ are shown in
A bottom shield 140 may optionally be provided, via step 302. Step 302 may include providing a multilayer or monolithic (single layer) magnetic shield. In other embodiments, step 302 may be omitted.
The bottom gap 190 may be provided, via step 304. Step 304 may include depositing a nonmagnetic layer. In some embodiments, the bottom gap and the side gap 180 are formed from a single layer and are provided together. In embodiments in which the bottom shield 140 is omitted, the bottom gap 190 provided in step 304 is desired to be thick as described above. Thus, the side shields extend well below the bottom of the pole tip 130. The pole 130 is provided, via step 306. Step 306 provides the pole such that the top is wider than the bottom. Thus, the sidewall angle, a, is formed. The side gap 180 is formed, via step 308. At least part of step 308 may be combined with step 304 if the side gap 180 and bottom gap 190 are formed together.
The side shields 150 are provided, via step 310. Thus, side shields 150 having pole-facing surfaces 152 that are close to (or at) vertical may be fabricated. The top shield 160 is provided, via step 312. The top shield 190 is magnetically coupled with the side shields 150. Thus, the side shields 150 may physically contact the top shield 160. Fabrication of the disk drive 100 may then be completed.
Using the method 300, the transducer 120 may be provided. Transducers 120′, 120″, 120′″, 220, 220′, 220″ and/or 220′″ may be fabricated in a similar fashion. Thus, the benefits described above for shingle recording may be achieved.
Claims
1. A shingle magnetic write apparatus comprising:
- a pole having a pole tip region including a bottom, a top wider than the bottom, a first side and a second side at a sidewall angle from a down track direction;
- a side gap adjacent to at least the first side and the second side;
- a write gap adjacent to the top of the pole;
- a top shield, the write gap being between the top shield and the top of the pole; and
- at least one side shield being magnetically connected with the top shield and extending past the bottom of the pole tip region, the side gap being between the at least one side shield and the pole, the at least one side shield having at least one pole-facing surface at a side shield angle from the down track direction, the side shield angle being less than the sidewall angle, being not more than five degrees, and being not less than two degrees from the down track direction.
2. The shingle magnetic write apparatus of claim 1 wherein the side gap has a width and wherein the side shield angle is not more than one-half of the sidewall angle such that the width of the side gap monotonically increases from the top of the pole toward the bottom of the pole.
3. The shingle magnetic write apparatus of claim 2 wherein the side shield angle is not more than one-third of the sidewall angle.
4. (canceled)
5. (canceled)
6. The shingle magnetic write apparatus of claim 1 wherein the sidewall angle is not more than fifteen degrees and at least four degrees.
7. The shingle magnetic write apparatus of claim 6 wherein the sidewall angle is not more than nine degrees.
8. The shingle magnetic write apparatus of claim 6 wherein the sidewall angle is at least twelve degrees.
9. The shingle magnetic write apparatus of claim 2 further comprising:
- a bottom shield; and
- a bottom gap residing between the bottom shield and the bottom of the pole, the bottom gap having a height greater than the width of the side gap.
10. The shingle magnetic write apparatus of claim 9 wherein the bottom shield is magnetically coupled with the at least one side shield.
11. A data storage device comprising:
- a media;
- a slider having an air-bearing surface (ABS) and a shingle magnetic write transducer, the shingle magnetic write transducer including a pole, a side gap, a write gap, a top shield and at least one side shield magnetically connected with the top shield, the pole having a pole tip region including a bottom, a top wider than the bottom, a first side and a second side at a sidewall angle from a down track direction, the side gap being adjacent to at least the first side and the second side, the write gap being adjacent to the top of the pole, the write gap being between the top shield and the top of the pole, the at least one side shield being magnetically connected with the top shield and extending past the bottom of the pole tip region, the side gap being between the at least one side shield and the pole, the at least one side shield having at least one pole-facing surface at a side shield angle from the down track direction, the side shield angle being not more than one-third of the sidewall angle, being not less than two degrees and being not more than five degrees.
12. The data storage device of claim 11 wherein the side gap has a width and wherein the shingle magnetic write transducer further includes:
- a bottom shield; and
- a bottom gap residing between the bottom shield and the bottom of the pole, the bottom gap having a height greater than the width of the side gap.
13. A method for fabricating a magnetic write apparatus comprising:
- providing a pole having a pole tip region including a bottom, a top wider than the bottom, and a plurality of sides comprising a first side and a second side at a sidewall angle from a down track direction;
- providing a side gap adjacent to at least the first side and the second side;
- providing a write gap adjacent to the top of the pole;
- providing a top shield, the write gap being between the top shield and the top of the pole; and
- providing at least one side shield magnetically connected with the top shield and extending past the bottom of the pole tip region, the side gap being between the at least one side shield and the pole, the at least one side shield having at least one pole-facing surface at a side shield angle from the down track direction, the side shield angle being less than the sidewall angle, being not less than two degrees and being not more than five degrees.
14. The method of claim 13 wherein the side gap has a width and wherein the side shield angle is not more than one-half of the sidewall angle such that the width of the side gap monotonically increases from the top of the pole toward the bottom of the pole.
15. The method of claim 14 wherein the side shield angle is not more than one-third of the sidewall angle.
16. (canceled)
17. (canceled)
18. The method of claim 14 further comprising:
- providing a bottom shield; and
- providing a bottom gap between the bottom shield and the bottom of the pole, the bottom gap having a height greater than the width of the side gap.
19. The method of claim 18 wherein the bottom shield is magnetically coupled with the at least one side shield.
Type: Application
Filed: Sep 30, 2015
Publication Date: Mar 30, 2017
Inventors: FENG LIU (SAN RAMON, CA), ZHIGANG BAI (FREMONT, CA), JINQIU ZHANG (FREMONT, CA), ZHANJIE LI (PLEASANTON, CA), YI WANG (MOUNTAIN VIEW, CA)
Application Number: 14/871,763