New dfh bulge with heat sink design

Abstract

To provide a heat-assisted magnetic recording (HAMR) read / write head that enhances touchdown (TD) protection for a reader or writer element.SOLUTION: A perpendicular magnetic recording (PMR) read / write head configured for heat-assisted magnetic recording (HAMR) generates thermally active bump portions when current flows through a heater element 10 formed on a centrally recessed heat sink 20 mounted on a read shield. When a heater element is activated by the current, thermal expansion of the centrally recessed heat sink forms bump portions, forming a symmetrical bumper pad. These thermally activated bumper pads function like symmetrical-shaped nano bumpers, and a PMR read / write head is mounted on a slider and built into a hard disk drive (HDD).SELECTED DRAWING: Figure 2B

Description

[Technical Field]

[0001] The present disclosure relates to magnetic recording / reproducing heads that write to and read from magnetic recording media, and more particularly to magnetic recording / reproducing head designs that provide thermally activated protection against media damage during dynamic events such as operational shocks, load / unload processes, and emergency power-offs. [Background technology]

[0002] Hard disk drives (HDDs) are increasing the recording density of magnetic disks on which data is stored. This trend is driving demands for improved performance from the thin-film magnetic heads that record and read that data. The most commonly used thin-film read / write heads are hybrid types that combine a magnetic field detection element, such as a giant magnetoresistive (GMR) read sensor, with a magnetic recording element, such as an electromagnetic coil induction element. These two types of devices are stacked on top of each other and mounted on a rectangular parallelepiped device called a slider. The slider is aerodynamically lifted at a height called the fly height (FH) and literally flies over the rotating surface of the disk. The read / write head is mounted on the slider and operates to read and write data signals from and to the magnetic disk, the typical magnetic recording medium of HDDs. The magnetic recording portion of the read / write head is a tiny electrically activated coil that induces a magnetic field in the magnetic pole. This magnetic field is generated in a narrow write gap (WG) and can change the magnetic moment of small magnetic particles or groups of particles embedded in the surface of the magnetic disk. If the magnetic moments of the embedded magnetic particles are perpendicular to the surface of the magnetic disk and in a manner that can be switched between up and down relative to the surface of the magnetic disk, it is called perpendicular magnetic recording (PMR). Such a perpendicular arrangement creates a more densely packed area for magnetic recording.

[0003] Perpendicular magnetic recording (PMR) heads, which record perpendicular to the surface of the recording medium, have increased the recording density of hard disk drives (HDDs) to 100 Gb / in 2 However, even with a PMR head, the thermal stability and superparamagnetic limit of the medium make it impossible to achieve a data rate of 1 Tb / in 2 Recording densities beyond this are difficult to achieve. To achieve even higher recording densities, a new technology called thermally assisted magnetic recording (HAMR) has been developed. Simply put, media that can be effectively used for such ultra-high-density recording must have an extremely high coercivity so that recorded data remains stable even when subjected to heat. However, the high coercivity required to maintain recorded data makes it difficult for the limited magnetic flux density of a compact PMR head to actually create magnetic transitions and record data onto the media. One way to achieve this is to heat the recording medium during the recording process, temporarily reducing the coercivity of the magnetic recording medium and then record the data on the heated surface. When the surface cools, the coercivity of the magnetic recording medium returns to its ambient value, and the data recorded on the magnetic recording medium becomes stable.

[0004] As is well known, a typical HAMR is a read / write head (here, a PMR head mounted on a slider) that includes (1) a laser diode that provides photothermal energy via optical radiation, (2) an optical waveguide that transmits the optical radiation to the vicinity of the recording surface, and (3) a plasmon generator located near the recording surface.

[0005] A plasmon generator is a device that receives optical radiation, converts it into excitation of plasmon modes via electromagnetic coupling, and transfers energy from the plasmon near-field to a region of the recording medium. Because the near-field is not radiation, it is not subject to diffraction and is highly localized. The localized near-field energy manifests as a near-field spot at the tip of the air-bearing surface (ABS) of the plasmon generator. This small near-field spot appears at the ABS of the PMR read / write head, adjacent to the tip of the magnetic pole from which the PMR write portion emerges. The near-field spot generated during a write operation causes a highly localized temperature increase in the magnetic recording medium. This reduces the coercivity of the magnetic recording medium, facilitating magnetic recording. At the same time, the near-field energy can produce very sharp or localized thermally induced protrusions, which present numerous challenges. Because this disclosure is directed to a recording / reading head, and these HAMR components that generate the near-field spot are already known in the art, the features of the HAMR head where the near-field energy is stored and where the read / write operation occurs will not be further described. As a result, HAMR drives use glass substrate media to address this issue.

[0006] To solve the temperature problem of the reader, a read heater heat sink is added between the read heater and the read shield, creating a read heater bulge. Summary of the Invention

[0007] The primary objective of this disclosure is to provide touchdown (TD) protection to various portions of a HAMR write head by adding "active" bumper pads that are generated by the thermal expansion of a central recessed heat sink, the shape of which is thermally altered by the effects of heat already generated within the write head.

[0008] A second objective of this disclosure is to provide a bumper pad that protrudes (from the area of ​​thermal expansion) due to the effects of heat already generated by elements within the HAMR head. This protrusion increases the TD contact area and improves reliability by controlling the location of the minimum point (closest to the disk) away from the sensor location.

[0009] A third objective of the present disclosure is to provide a bumper pad whose global and local protrusion effect shifts the TD contact points to the shield and other areas designed to absorb the contact, thereby avoiding contact with more sensitive areas of the write head.

[0010] A fourth object of the present disclosure is to provide a bumper pad whose shape can be controlled to create thermal protrusion asymmetry that may be beneficial to the performance of a HAMR recording head.

[0011] The objectives of the present disclosure are realized by the design of a HAMR read / write head configured for perpendicular magnetic recording (PMR). The HAMR read / write head includes a magnetically shielded GMR read head and a separate magnetically shielded inductive write head driven by a write current. These elements protrude from the ABS of the PMR. The PMR also includes independently operating heater elements Hr and Hw. These heater elements are positioned adjacent to the read and write heads, respectively, but are closely spaced from the ABS. The PMR also includes at least one head-disk interference sensor (HDI), which is mounted on the read / write head. To utilize the HAMR system, the write head forms a narrow write region at the ABS, where magnetic flux emanates from a protruding pole tip and near-field plasmon energy is emitted from the trailing edge of the pole tip to enable writing to the magnetic recording medium. Finally, a pair of thermally activated bumper pads, whose shape changes due to localized thermally induced protrusions, are positioned on either side of the narrow write region of the write element to protect the write region by shifting the potential point of disk contact away from the write head and toward the magnetic shield in the event of touchdown (TD) or other forms of head-disk interference (HDI). [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram of a conventional HAMR head, showing a heat sink between the lead heater and the read shield. [Figure 2A] FIG. 2A is a conventional heat sink and lead heater. [Figure 2B] FIG. 2B is a central recessed heat sink for the DFH bulge of the present disclosure. [Figure 3A] FIG. 3A shows the lead heater bulge in the center of the slider above the conventional DFH bulge in the down-track direction. [Figure 3B]FIG. 3B shows a read heater bulge in the center of the slider above a conventional DFH bulge in the cross-track direction. [Figure 3C] FIG. 3C shows the lead heater bulge in the center of the slider above the novel DFH bulge in the down-track direction. [Figure 3D] FIG. 3D shows the lead heater bulge in the center of the slider above the novel DFH bulge in the cross-track direction. [Figure 4A] FIG. 4A shows the read flying height (FH) profile at read touchdown in the down-track direction for a conventional bulge. [Figure 4B] FIG. 4B shows the read flying height (FH) profile at read touchdown in the cross-track direction for a conventional bulge. [Figure 4C] FIG. 4C shows the read flying height (FH) profile at read touchdown in the down-track direction of the bulge of the present disclosure. [Figure 4D] FIG. 4D shows the read flying height (FH) profile at read touchdown in the cross-track direction of the bulge of the present disclosure. [Figure 5A] Figure 5A shows the touchdown region produced by a conventional bulge. [Figure 5B] FIG. 5B shows the touchdown region created by the bulge of the present disclosure. [Figure 6] FIG. 6 shows a head gimbal assembly (HGA) on which the PMR head of the present disclosure is flexibly mounted. [Figure 7] FIG. 7 shows a side view of the pair of HGAs shown in FIG. [Figure 8] FIG. 8 is a top view of the HGA shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] To reduce the temperature rise of the reader caused by the activated read heater, a heat sink is placed between the reader shield S1 and the read heater. The read element (GMR element) is placed between the read shield S1 and the read shield S2A. Figure 1 shows the structure of the read heater 10, shields 30, 35, and heat sink 20. Also shown is a portion of the write coil 100, which will not be described.

[0014] During the operation of the lead heater, the lead heater transfers heat to the heat sink, which then transfers the heat to the lead shield S1. Thermal expansion of the heat sink and lead shield results in a bulge in the heater. Because the lead heater is not directly heated by the shield S1, inserting the heat sink effectively reduces the temperature of the lead. However, the shape of the heater bulge is independent of the shape of the lead heater. We propose a heat sink design that achieves a novel bulge to protect the lead. Figure 2A shows a conventionally shaped heat sink and lead heater, while Figure 2B shows the heat sink and lead heater of the present disclosure.

[0015] The lead heater protrusion adjusts the reader spacing and ensures sufficient TD area to induce vibration of the lead heater TD. Figures 3A and 3B show the conventional lead heater protrusion as viewed from the down-track and cross-track directions, respectively. Figures 3C and 3D show the novel lead heater protrusion as viewed from the down-track and cross-track directions, respectively. The maximum protrusion point of the conventional heater is at the center of the slider, very close to the reader element. However, the protrusion of the present disclosure has two peaks that function like nanobumpers, dividing the maximum protrusion points so that they are separated by ±6 μm from the center in the cross-track direction. To protect the reader element from HDI / TD wear, the reader is located at the center (not the protruding peak) and the two peaks (nanobumpers).

[0016] Figures 4A and 4B show the read flying height (FH) profile during read touchdown in the down-track direction for a conventional ridge, respectively. Figures 4C and 4D show the read flying height (FH) profile during read touchdown in the down-track direction for a ridge of the present disclosure, respectively. The reader spacing of a conventional read heater is less than 0.1 nm (nanometer) (Figure 1A). The DFH bulge design of the present disclosure protects the reader element during RTD (read touchdown) with a "nano-bumper." When using the heat sink of the present disclosure and a conventional read heater, the reader spacing is 0.3 nm during RTD (reader touchdown). By fine-tuning the shape of the heat sink according to the wear of the HDI / TD by the HDD, the reader spacing can be adjusted in the range of 0 to 1 nm.

[0017] Furthermore, the DFH bulge designed this time has a wider bulge width than the conventional bulge. This increases the TD area, enabling sufficient TD vibration to be generated in the drive. As shown in Figure 5A, the conventional reader TD area is 108 (micrometers squared), but with the proposed bulge, the reader TD area is increased to 122 (micrometers squared), as shown in Figure 5B. The bulge width and maximum protrusion position can be adjusted by fine-tuning the heat sink design.

[0018] Based on the modeling results shown in the figures, the disclosed design has many advantages, including: (1) By adjusting the dimensions and protrusion of the bumper, the contact area can be controlled to prevent TD “overpush” (excessive compensation of heater power due to TD detection failure). (2) The minimum point shift from the sensor to the bumper pad can be controlled to improve head reliability. (3) The local protrusion height and shape of the bumper can be adjusted by selecting the bumper dimensions to suit different wafer designs, head processes, and writing conditions. (4) The DFH bulge described here has two peaks. (5) By adjusting the dimensions and protrusion of the bumper, the contact area can be controlled to prevent TD “overpush” (excessive compensation of heater power due to TD detection failure). (6) To improve head reliability, it is possible to control the minimum point shift from the sensor to the bumper pad. (7) The local protrusion height and shape of the bumper can be adjusted by selecting the bumper dimensions to suit different wafer designs, head processes, and writing conditions. (8) DFH Double peak functions as a "nano bumper" that protects the reader from HDI / TD wear by moving the TD point from the center to the nano bumper (S1 lead shield side). (9) In the disclosed design, the leader spacing @TD is 0.3 nm. By fine-tuning the heater design according to the HDI / TD wear conditions of the HDD, it is possible to adjust the wear from 0nm to 1nm. (10) The DFH bulge disclosed this time reduces the TD area to 55 μm 2 to 88 μm 2 and sufficient TD vibration can be obtained.

[0019] FIG. 6 shows a head gimbal assembly (HGA) 1200 including a PMR writer 1100 mounted on a slider. The slider provides aerodynamic support for the writer as it moves above or below a disk recording medium 1140 during operation. Also shown is a suspension 1220 that resiliently supports the writer 1100 mounted on the slider. The suspension 1220 includes a spring-like load beam 1230 made of a thin, corrosion-resistant, elastic material such as stainless steel. The load beam has a flexure 1230 at its distal end and a base plate 1240 at its proximal end. The slider-mounted TAMR writer 1100 is attached to the load beam 1230 by a flexure 1231, which provides the TAMR with an appropriate degree of freedom of movement. The portion of the flexure 1231 where the TAMR 1100 is mounted has a gimbal section to maintain the PMR read / write head at the appropriate height.

[0020] The member in which the HGA 1200 is attached to the arm 1260 is called the head arm assembly 1220. The arm 1260 moves the read / write head 1100 in the cross-track direction (arrow) over the medium 1140 (here, a hard disk). One end of the arm 1260 is attached to the base plate 1240. A coil 1231, which is part of a voice coil motor (not shown), is attached to the other end of the arm 1260. A bearing 1233 is provided in the middle of the arm 1260. The arm 1260 is rotatably supported by a shaft 1234 attached to the bearing 1233. The arm 1260 and the voice coil motor that drives the arm 1260 form an actuator.

[0021] 7 and 8, there is shown a head stack assembly 1250 and a magnetic recording device incorporating a slider-mounted TAMR writer 1100. The head stack assembly is an element in which the HGA 1200 is attached to the arm of a carriage having multiple arms for engaging multiple disks 1140. The disks are mounted on a spindle 1261. FIG. 5 is a side view of this assembly, and FIG. 6 is a plan view of the entire magnetic recording device.

[0022] Finally, referring to FIG. 8, the head stack assembly 1250 is shown incorporated into a magnetic recording device 1290. The magnetic recording device 1290 includes multiple magnetic recording media 1114 mounted on a spindle motor 1261. Each recording medium 1114 is provided with two TAMR elements 1100 positioned opposite each other across the magnetic recording medium 1114 (as clearly shown in FIG. 5). The head stack assembly 1250 and actuator (excluding the write head itself) function as a positioning device to support the PMR head 1100 and, in response to electronic signals, position the PMR head correctly facing the media surface. The read / write head uses its internal magnetic poles to record information on the magnetic media surface.

[0023] As will be appreciated by those skilled in the art, the present disclosure is illustrative rather than limiting. Modifications and variations can be made to the methods, materials, structures, and dimensions used in forming and providing a PMR recording head mounted on an HDD slider configured for HAMR. The slider has an ABS topography including a symmetrically arranged central concave heater bulge and an active bumper pad formed from a central concave heat sink, symmetrically surrounding a narrow write area configured to operate in conjunction with a plasmonic near-field spot. The thermally active bulge undergoes a shape change due to thermal protrusion effects occurring within the PMR, which protects portions of the PMR head during intentional and unintentional TD events while allowing for the formation and provision of such a device and its method of operation within the spirit and scope of the present disclosure, as defined by the appended claims.

Claims

1. a perpendicular magnetic recording (PMR) read / write head for HAMR; The PMR read / write head includes a giant magnetoresistive (GMR) read head exposed to the ABS of the PMR and magnetically shielded, and a separate, magnetically shielded, inductive write head exposed to the ABS of the PMR and activated by a write current. a heater element Hr and a heater element Hw disposed adjacent to the read head and the write head, respectively, and spaced apart from the ABS, and operating independently; the read heater mounted on a centrally recessed heat sink which itself is mounted on the heater shield, the resulting structure producing a double-peaked dynamic flying height (DFH) bulge, or a multi-recessed heat sink producing a multi-peaked DFH bulge; Equipped with The bumps create a pair of thermally activated nano-bumper pads, the shape of which is altered by the localized heat-induced protrusions formed by the bumps, positioned on either side of the narrow write area of ​​the write element to protect the area in the event of read touchdown (RTD) or other forms of head-disk interference (HDI) by shifting potential points of disk contact toward the protrusions. Heat-assisted magnetic recording (HAMR) read / write head.

2. The pair of thermally active bumper pads formed from the protuberances extend proximally from the ABS and are configured to absorb thermal energy generated by the heater, the write current, and the HAMR device, thereby thermally protruding the bumper pads and increasing the surface area of ​​the write head for added protection during intentional or accidental read touchdown (RTD) or other forms of head-disk interference (HTI). The heat-assisted magnetic recording (HAMR) read / write head of claim 1 .

3. both of the active bumper pads have the same shape and are symmetrically arranged, whereby each of the active bumper pads, when thermally activated, produces a protrusion similar to that of the other active bumper pad, symmetrically changing the response of the slider in the cross-track direction under TD conditions; The heat-assisted magnetic recording (HAMR) read / write head of claim 1 .

4. Both active bumper pads are identical in shape and function like identical nano-bumpers, with surfaces extending proximally rearward from the ABS and passing over an inductive magnetic coil element, such that each active bumper pad absorbs heat generated by the magnetic coil element during the write process. The heat-assisted magnetic recording (HAMR) read / write head of claim 1 .

5. each active bumper pad is the same shape as the other active bumper pads, and when the pads are thermally activated, each active bumper pad generates a similarly shaped protrusion from the other active bumper pads, thereby symmetrically changing the response of the slider under TD conditions; and the dual peak DFH protuberance can protect a read transducer, a write transducer, or a HAMR near-field transducer. The heat-assisted magnetic recording (HAMR) read / write head of claim 1 .

6. The shape of the thermally active bumper pad is adjusted by the bulge shape, which is the height of the nano-bumper, and the bulge shape is adjusted by fine-tuning the heat sink according to the HDI / TD wear conditions in the HDI. The heat-assisted magnetic recording (HAMR) read / write head of claim 1 .

7. During touchdown (TD), the thermally activated bumper pad moves the slider ABS's closest point to the disk media from the HDI to the activated bumper pad, improving both TD detection and head reliability. The heat-assisted magnetic recording (HAMR) read / write head of claim 1 .

8. By adjusting the size and shape of each active bumper pad and the distance between the two bumper pads, the active bumper pads can be adapted to different head designs, writing conditions, and head manufacturing processes. The heat-assisted magnetic recording (HAMR) read / write head of claim 1 .

9. The HAMR read / write head of claim 1 is mounted on a slider; the slider is aerodynamically configured to maintain the HAMR read / write head at a predetermined flying height when the slider is flying above a rotating magnetic-recording disk, and a thermal protrusion on the active bumper pad controls the minimum flying height point of the slider during a touchdown (TD) event. head.

10. the thermal protrusion caused by the active bumper pad increases the area of ​​the slider ABS closest to the disk media during a touchdown (TD) event, thereby allowing the HDI to more uniformly approach the disk media and making the TD event more easily detected by the HDI; 10. The slider-mounted HAMR read / write head of claim 9.

11. The active bumper pad shifts the point of minimum approach at touchdown (TD) of the slider ABS to a larger shield away from the exposed sensitive areas on the ABS, thereby improving head reliability.

10. The slider-mounted HAMR read / write head of claim 9.

12. The active bumper pad shifts the point of minimum approach at touchdown (TD) of the slider ABS from the exposed sensitive area on the ABS to a larger shield, thereby improving head reliability.

10. The slider-mounted HAMR read / write head of claim 9.

13. The disclosed design has a 0.3 nm leader spacing in the TD, but the spacing can be adjusted from 0 nm to 1 nm by fine-tuning the heater design depending on HDI / TD wear.

10. The slider-mounted HAMR read / write head of claim 9.

14. The DFH bulge reduces the TD area to 108 μm for sufficient TD vibration. ２ to 122 μm ２ Increase to.

10. The slider-mounted HAMR read / write head of claim 9.

15. The DFH bulge is characterized by controlling the size of the contact area by the size and protrusion of the bumper to prevent "over-pressure" of the TD, i.e., over-compensation of heater power due to TD detection failure.

10. The slider-mounted HAMR read / write head of claim 9.

16. Minimizing point shift from the sensor to the bumper pad reduces wear and improves head reliability.

10. The slider-mounted HAMR read / write head of claim 9.

17. (a) a HAMR device according to claim 1; (b) a suspension that elastically supports the HAMR device and includes a flexure to which the HAMR device is joined, and a load beam that is connected to the flexure at one end and to a base plate at the other end; A head gimbal assembly (HGA) comprising:

18. (a) the HGA of claim 17; (b) a magnetic recording medium disposed opposite to a slider on which the magnetic reproducing head structure is formed; (c) a spindle motor that rotates the magnetic recording medium; and (d) a device for supporting the slider and positioning the slider relative to the magnetic recording medium; A magnetic recording device comprising:

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