Manufacturing method for disk device and disk device

Abstract

To provide a manufacturing method for a disk device suitable for improving yield at a self-servo write process, and a disk device.SOLUTION: According to one embodiment, a manufacturing method for a disk device is provided. The manufacturing method for the disk device includes acquiring information about a write width of a head. The manufacturing method for the disk device includes adjusting the seek speed of the head when writing a spiral pattern to a disk according to the acquired write width.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present embodiment relates to a method for manufacturing a disk device and a disk device. [Background technology]

[0002] Disk drives are often manufactured through a self-servo write process, in which a spiral pattern is written on the disk, and a servo pattern is written based on the spiral pattern. To reduce the manufacturing costs of disk drives, it is desirable to improve the yield of this self-servo write process. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 9,076,490 [Patent Document 2] U.S. Patent No. 8,514,510 [Patent Document 3] US Patent Application Publication No. 2012 / 0229930 [Patent Document 4] U.S. Patent No. 6,692,852 [Patent Document 5] U.S. Patent No. 7,054,090 [Patent Document 6] U.S. Patent No. 6,493,176 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of one embodiment is to provide a method for manufacturing a disk device suitable for improving the yield of the self-servo write process, and a disk device. [Means for solving the problem]

[0005] According to one embodiment, there is provided a method for manufacturing a disk drive, the method including acquiring information on a write width of a head, and adjusting a seek speed of the head when writing a spiral pattern to a disk, in accordance with the acquired write width. [Brief explanation of the drawings]

[0006] [Figure 1] 4 is a flowchart showing a method for manufacturing a disk device according to an embodiment. [Figure 2] FIG. 1 is a diagram showing the configuration of a disk device according to an embodiment. [Figure 3] 3A and 3B are diagrams showing the arrangement of guide spiral patterns on a disc according to an embodiment. [Figure 4] FIG. 3 is a diagram showing a format of control information according to an embodiment. [Figure 5] 10 is a flowchart showing an adjustment process in the embodiment. [Figure 6] 5A and 5B are diagrams showing the arrangement of adjustment patterns on a disk in the embodiment. [Figure 7] 5A and 5B are diagrams showing the configuration of adjustment patterns in the embodiment. [Figure 8] FIG. 10 is a diagram showing a read signal of an adjustment pattern with respect to an offset amount SA1 in the embodiment. [Figure 9] FIG. 10 is a diagram showing a read signal of an adjustment pattern with respect to an offset amount SA2 in the embodiment. [Figure 10] FIG. 10 is a diagram showing a read signal of an adjustment pattern with respect to an offset amount SA3 in the embodiment. [Figure 11] FIG. 10 is a diagram showing how to obtain a write width in the embodiment. [Figure 12] FIG. 4 is a diagram showing a method for determining a seek speed in an embodiment. [Figure 13] FIG. 10 is a diagram showing a spiral pattern written at a slow seek speed in an embodiment. [Figure 14] FIG. 10 is a diagram showing a spiral pattern written at a medium seek speed in an embodiment. [Figure 15] 10A and 10B are diagrams showing spiral patterns written at a high seek speed in an embodiment. [Figure 16] 3A and 3B are diagrams showing the layout of spiral patterns on a disk according to an embodiment. [Figure 17] FIG. 4 is a diagram showing a read signal of a spiral pattern in the embodiment. [Figure 18] 3A and 3B are diagrams showing the arrangement of servo patterns on a disk in the embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0007] A method for manufacturing a disk device according to an embodiment will be described in detail below with reference to the accompanying drawings, although the present invention is not limited to the embodiment.

[0008] (Embodiment) The manufacturing method of the disk device according to the embodiment includes a self-servo write process, and is devised to improve the yield of the self-servo write process. For example, the manufacturing method of the disk device 1 includes a blank disk write (BDW) process and a self-servo write (SSW) process, as shown in Fig. 1. Fig. 1 is a flowchart showing the manufacturing method of the disk device 1.

[0009] In the BDW process (S1), a guide spiral pattern is written on a blank disk, and a spiral pattern is written on the disk using the written guide spiral pattern. In the SSW process (S2), a servo pattern is written on the disk using the written spiral pattern. The spiral pattern is also called a final spiral pattern. The servo pattern is also called a product servo pattern.

[0010] In the BDW step (S1), a disk device 1 is prepared as shown in Fig. 2. Fig. 2 is a diagram showing the configuration of the disk device 1.

[0011] The disk device 1 is connected to a port PT of a manufacturing rack RC in the manufacturing system 100 and can communicate with a rack terminal RT via the manufacturing rack RC. The manufacturing system 100 may include a plurality of manufacturing racks RC. Each manufacturing rack RC has a rack interface (rack I / F) 101 and a plurality of pallets PL_1 to PL_k, where k is an integer of 2 or greater. Each pallet PL_1 to PL_k has a pallet interface (pallet I / F) 102 and a plurality of ports PT_1 to PT_n, where n is an integer of 2 or greater. Each port PL is connected to a connector 40 of the disk device 1.

[0012] The disk device 1 is connected to the port PT during the manufacturing process, but can be connected to the host 2 after the manufacturing process is completed. The standard of the communication path between the disk device 1 and the host 2 is not limited to a specific standard. As an example, SATA (Serial Advanced Technology Attachment) or SAS (Serial Attached SCSI) can be adopted. The connector 40 may include a SATA connector or a UART (Universal Asynchronous Receiver / Transmitter) connector. The disk device 1 functions as a storage medium for the host 2. The disk device 1 is, for example, a disk-type storage medium such as an HDD (Hard Disk Drive) or an optical disk drive.

[0013] The host 2 is, for example, a processor, a personal computer, a server, etc. The disk device 1 can receive access commands (read commands and write commands) from the host 2.

[0014] The disk device 1 includes a plurality of disks 10 that rotate around a rotation axis 12 of a spindle motor (SPM) 11. As an example, the disk device 1 includes six disks 10-1, 10-2, 10-3, 10-4, 10-5, and 10-6. The six disks 10-1, 10-2, 10-3, 10-4, 10-5, and 10-6 are rotated together by the SPM 11.

[0015] The disks 10 are substantially disc-shaped media on which information is to be recorded. The disks 10 may be magnetic disks or magneto-optical disks. When the disks 10 are magnetic disks, the six disks 10 have recording surfaces on the front and back sides thereof on which data can be recorded. In other words, the six disks 10 have 12 recording surfaces. To access each of the 12 recording surfaces, the disk device 1 has 12 heads HD1 to HD12 corresponding to the 12 recording surfaces.

[0016] Head HD1 is provided to face the front surface of disk 10-1. Head HD2 is provided to face the back surface of disk 10-1. Head HD3 is provided to face the front surface of disk 10-2. Head HD4 is provided to face the back surface of disk 10-2. Head HD5 is provided to face the front surface of disk 10-3. Head HD6 is provided to face the back surface of disk 10-3. Head HD7 is provided to face the front surface of disk 10-4. Head HD8 is provided to face the back surface of disk 10-4. Head HD9 is provided to face the front surface of disk 10-5. Head HD10 is provided to face the back surface of disk 10-5. Head HD11 is provided to face the front surface of disk 10-6. Head HD12 is provided to face the back surface of disk 10-6.

[0017] Hereinafter, the 12 heads HD1 to HD12 may be collectively referred to as heads HD. Each head HD can access the recording surfaces of the six disks 10 facing it, that is, write information and read data. Each head HD includes a write element WE and a read element RE, and writes information to the disks 10 using the write element WE and reads information from the disks 10 using the read element RE.

[0018] The disk device 1 includes an actuator system 20 that moves the 12 heads HD as a unit. The actuator system 20 includes seven actuator arms 21, 12 suspensions 22, and a voice coil motor (VCM) 23. Each of the 12 suspensions 22 included in the actuator system 20 supports one of the heads HD1 to HD12. Each of the 12 suspensions 22 included in the actuator system 20 is attached to the tip of one of the seven actuator arms 21.

[0019] Actuator system 20 is rotatable about rotation axis 24. Rotation axis 24 is provided in a position parallel to and spaced apart from rotation axis 12. VCM 23 can rotate actuator system 20 within a predetermined range about rotation axis 24. Therefore, actuator system 20 can move heads HD1 to HD12 radially relative to the recording surfaces of disks 10-1 to 10-6.

[0020] The disk device 1 further includes an SVC (servo controller) 31, a head amplifier 32, a nonvolatile memory 33, a volatile memory 34, a processor 35, an RWC (read / write channel) 36, and an HDC (hard disk controller) 37.

[0021] The head amplifier 32 supplies a signal corresponding to the write data input from the RWC 36 to the head HD facing the recording surface to be written to. The head amplifier 32 also amplifies the signal output from the head HD facing the recording surface to be read and supplies it to the RWC 36.

[0022] The nonvolatile memory 33 is, for example, a flash memory. The nonvolatile memory 33 stores programs executed by the processor 35. In the manufacturing process of the disk device 1, the programs executed by the processor 35 include a BDW program, an SSW program, etc. After the manufacturing process of the disk device 1 is completed, the programs executed by the processor 35 include firmware for normal operation, etc.

[0023] The volatile memory 34 is configured by a volatile memory such as a DRAM (Dynamic Random Access Memory) or an SRAM (Static Random Access Memory). The volatile memory 34 is provided with an area for buffering write data received from the host 2 before being written to the disk 10, and read data read from the disk 10 before being sent to the host 2.

[0024] The RWC 36 modulates the write data buffered in the volatile memory 34 and outputs the modulated data to the head amplifier 32. The RWC 36 also demodulates the signal supplied from the head amplifier 32 and outputs the demodulated signal to the HDC 37.

[0025] In the manufacturing process of the disk device 1, the HDC 37 is a communication interface that enables communication with the port PT. Specifically, the HDC 37 can send a predetermined request to the rack terminal RT via the port PT, the pallet I / F 102, and the rack I / F 101. When the rack terminal RT receives the predetermined request, it sends response information in response to the predetermined request. The HDC 37 receives the response information from the rack terminal RT via the rack I / F 101, the pallet I / F 102, and the port PT.

[0026] After the manufacturing process of the disk device 1 is completed, the HDC 37 is a communication interface that enables communication with the host 2. Specifically, when the HDC 37 receives a write command from the host 2, it stores the write data in the volatile memory 34, and returns a response to the host 2 when writing of the write data to the disks 10 is completed. Furthermore, when the HDC 37 receives a read command from the host 2, it reads the data requested to be read by the read command (read data) from the disks 10 and buffers it in the volatile memory 34, and then returns the read data buffered in the volatile memory 34 to the host 2.

[0027] The SVC 31 supplies a control signal to the SPM 11 to rotate the SPM 11 at a predetermined frequency and phase. The control signal may be a control current or a control voltage.

[0028] The SVC 31 also drives the VCM 23 to move the head HD to a position specified by the processor 35 .

[0029] The processor 35 is, for example, a CPU (Central Processing Unit). The processor 35 executes various processes according to programs stored in a nonvolatile storage medium such as the nonvolatile memory 33 or the disk 10.

[0030] For example, the processor 35 controls the writing and reading of data by the head HD, determines the access position on the recording surface of the disk 10, and instructs the servo controller 31 on the access position.

[0031] The servo controller 31, head amplifier 32, nonvolatile memory 33, volatile memory 34, processor 35, RWC 36, and HDC 37 constitute the controller 30. However, the components of the controller 30 are not limited to these.

[0032] Returning to FIG. 1, in the BDW step (S1), the disc device 1 writes a guide spiral pattern 11 onto a blank disc 10 (S3).

[0033] The disk device 1 may use any one of the heads HD1 to HD12 to write a plurality of guide spiral patterns 11_1 to 11_3 as shown in FIG. 3 onto the corresponding recording surface of the disk 10. FIG. 3 is a diagram showing the arrangement of the guide spiral patterns 11 on the disk 10. In FIG. 3, the rotation direction of the disk 10 is indicated by a dashed arrow. Each guide spiral pattern 11 extends in a spiral shape from the inner periphery to the outer periphery of the disk 10. Although FIG. 3 illustrates an example in which three guide spiral patterns 11_1 to 11_3 are written, the number of guide spiral patterns 11 may be one or two, or may be four or more.

[0034] The disk device 1 rotates the disk 10 at a predetermined rotational speed and controls the positioning of the head HD to a first position on the inner periphery according to the predetermined rotational speed. While rotating the disk 10 at the predetermined rotational speed, the disk device 1 moves (seeks) the head HD from the inner periphery to the outer periphery of the disk 10 at a predetermined seek speed to a target position on the disk 10, and writes control information IF2 using the write element WE.

[0035] The disk device 1 may write control information IF2 as shown in FIG. 4 to the disk 10. FIG. 4 is a diagram showing the format of the control information IF2. The control information IF2 includes sync marks at a predetermined frequency, and includes basic dibits between each sync mark. The sync marks are used to adjust the seek speed, which will be described later. The basic dibits are used to adjust the amplitude of the read signal.

[0036] The disk device 1 writes the control information IF2 in a spiral shape on the disk 10. As a result, the guide spiral pattern 11_1 is written on the disk 10.

[0037] Similarly, the disk drive 1 controls the positioning of the head HD to a second position on the inner periphery side in accordance with a predetermined rotational speed. The second position is shifted a predetermined amount in the circumferential direction from the first position. While rotating the disk 10 at a predetermined rotational speed, the disk drive 1 causes the head HD to seek from the inner periphery side to the outer periphery side of the disk 10 at a predetermined seek speed, and writes control information IF2 with the write element WE. As a result, the guide spiral pattern 11_2 is written on the disk 10.

[0038] The disk device 1 controls the positioning of the head HD to a third position on the inner periphery side in accordance with a predetermined rotational speed. The third position is shifted a predetermined amount in the circumferential direction from the second position. While rotating the disk 10 at a predetermined rotational speed, the disk device 1 causes the head HD to seek from the inner periphery side to the outer periphery side of the disk 10 at a predetermined seek speed, and writes control information IF2 with the write element WE. As a result, the guide spiral pattern 11_3 is written on the disk 10.

[0039] In the BDW step (S1), the disk device 1 performs an adjustment process to adjust the seek speed for tracking the guide spiral pattern 11 and writing the spiral pattern 22 (S4).

[0040] In S4, the processes of S11 to S16 shown in Fig. 5 are carried out. Fig. 5 is a flowchart showing the adjustment process (S4).

[0041] In S11, the disk device 1 uses the head HD of S3 to perform tracking on the guide spiral pattern 11. The disk device 1 controls the positioning of the head HD to a predetermined cylinder on the inner periphery in accordance with the information read from the guide spiral pattern 11 by the head HD of S3, and performs tracking on the predetermined cylinder.

[0042] In S12, the disk device 1 writes the adjustment pattern 12 in the circumferential direction using a head HD different from the head HD in S3 (S12).

[0043] The disk device 1 may write an adjustment pattern 12 as shown in Fig. 6 onto the disk 10 using a head HD different from the head HD of S3 among the multiple heads HD1 to HD12. Fig. 6 is a diagram showing the arrangement of the adjustment pattern 12 on the disk 10. Fig. 6 shows an example of an adjustment pattern 12 that extends in a circular shape with a portion missing in the circumferential direction of the disk 10. In Fig. 6, the rotation direction of the disk 10 is indicated by a dashed line.

[0044] The disk device 1 rotates the disk 10 at a predetermined rotational speed, and controls the positioning of the head HD to a fourth position on the inner periphery according to information read from the guide spiral pattern 11. The fourth position may be a position slightly outer than the innermost position on the disk 10. While rotating the disk 10 at a predetermined rotational speed, the disk device 1 writes control information IF2 using the write element WE without causing the head HD to seek.

[0045] The disk device 1 controls the positioning of the head HD to a fourth position and writes the control information IF2 (see FIG. 4) in the circumferential direction on the disk 10. The disk device 1 may write the control information IF2 in the circumferential direction so that the write range of the control information IF2 is shorter than one revolution. As a result, the adjustment pattern 12 is written on the disk 10, as shown in FIG. 7. FIG. 7 is a diagram showing the configuration of the adjustment pattern 12. In FIG. 7, the vertical axis indicates the radial position, and the horizontal axis indicates the circumferential position. In FIG. 7, the rotation direction of the disk 10 is indicated by a dashed arrow, and the direction in which the write element WE moves relative to the disk 10 is indicated by a dotted arrow.

[0046] The period of the Sync marks in the adjustment pattern 12 may be equal to the period of the Sync marks in the guide spiral pattern 11. The format of the adjustment pattern 12 may be equal to the format of the guide spiral pattern 11.

[0047] In S13, the disk device 1 performs a partial read with the head HD of S12, changes the tracking position, and finds the adjustment pattern 12. While tracking the guide spiral pattern 11, the disk device 1 performs a partial read with the read element RE of the head HD of S12, changes the tracking cylinder, and finds the adjustment pattern 12. The read time width can be set by the time width during which the read gate is at an active level. The time width during which the read gate is at an active level is set, for example, to a range in which a predetermined number or more of Sync numbers can be detected consecutively. The predetermined number corresponds to the maximum amplitude of the read signal, and may be, for example, 10. The number of reads is, for example, 10 to 30 locations per rotation.

[0048] In S14, the readable offset range (=write width) is measured for the adjustment pattern 12 found in S13. The readable offset range can also be rephrased as the radial position range in which the adjustment pattern 12 can be read. Whether or not it is readable is determined, for example, when the number of Syncs detected is equal to or greater than the slice level on average. The slice level is a number between 0 and a predetermined number, which may be, for example, 5.

[0049] For example, the disk device 1 controls the positioning of the read element RE of the head HD to a radial position by an offset amount SA0 (see FIG. 11) in the radial direction from the track center TC. The offset amount SA0 corresponds to the read element RE passing through the radially inner side of the adjustment pattern 12. The disk device 1 reads the adjustment pattern 12 with the read element RE, but because it passes through the radially inner side of the adjustment pattern 12, the level of the obtained read signal is almost zero, and the number of Syncs in the read signal is detected as almost zero.

[0050] As shown in Fig. 8, the disk device 1 controls the positioning of the read element RE of the head HD to a radial position offset by an offset amount SA1 in the radial direction from the track center TC. Fig. 8 is a diagram showing the read signal of the adjustment pattern 12 with respect to the offset amount SA1. The offset amount SA1 is larger than the offset amount SA0, and corresponds to the read element RE passing near the edge on the inner periphery side of the adjustment pattern 12. When the disk device 1 reads the adjustment pattern 12 with the read element RE, as shown in Fig. 8, the obtained read signal has a predetermined amplitude or more in the positive and negative directions, and the number of Syncs in the read signal is detected to be equal to or greater than the slice level (for example, 10).

[0051] As shown in Fig. 9, the disk device 1 controls the positioning of the read element RE of the head HD to a radial position offset by an offset amount SA2 in the radial direction from the track center TC. Fig. 9 is a diagram showing the read signal of the adjustment pattern 12 with respect to the offset amount SA2. The offset amount SA2 is larger than the offset amount SA1, and corresponds to the read element RE passing near the center of the adjustment pattern 12 in the radial direction. When the disk device 1 reads the adjustment pattern 12 with the read element RE, as shown in Fig. 9, the obtained read signal has a predetermined amplitude or more in the positive and negative directions, and the number of Syncs in the read signal is detected to be equal to or greater than the slice level (for example, 10).

[0052] As shown in Fig. 10, the disk device 1 controls the positioning of the read element RE of the head HD to a radial position offset by an offset amount SA3 in the radial direction from the track center TC. Fig. 10 is a diagram showing the read signal of the adjustment pattern 12 with respect to the offset amount SA3. The offset amount SA3 is larger than the offset amount SA2, and corresponds to the read element RE passing near the edge on the outer periphery of the adjustment pattern 12. When the disk device 1 reads the adjustment pattern 12 with the read element RE, as shown in Fig. 10, the obtained read signal has a predetermined amplitude or more in the positive and negative directions, and the number of Syncs in the read signal is detected to be equal to or greater than the slice level (for example, 10).

[0053] The disk device 1 controls the positioning of the read element RE of the head HD to a radial position by an offset amount SA4 (see FIG. 11) in the radial direction from the track center TC. The offset amount SA4 corresponds to the read element RE passing on the radial outside of the adjustment pattern 12. The disk device 1 reads the adjustment pattern 12 with the read element RE, but because it passes on the radial outside of the adjustment pattern 12, the level of the obtained read signal is almost zero, and the number of Syncs in the read signal is detected as almost zero.

[0054] According to the measurement results shown in Figures 8 to 10, the readable offset range (=write width) can be obtained as shown in Figure 11. Figure 11 is a diagram showing how to obtain the write width.

[0055] Whether or not reading is possible is determined, for example, when the number of Syncs detected is equal to or greater than the slice level (for example, 5) on average. To measure the readable offset range, an offset amount from the reference position is given in increments of a predetermined width (for example, 1 / 20 of the track width), and it is measured whether or not the adjustment pattern 12 can be read. The offset range (= write width W WE ) is calculated. WE corresponds to the radial width of the write element WE. In the case of FIG. 11, the maximum and minimum values ​​of the readable offset are SA3 and SA1, respectively, and the write width W of the head HD is WE can be calculated by the following formula 1. W WE =SA3-SA1 Formula 1

[0056] In S15, the disk device 1 writes the data with a write width W WE Depending on the size of the write width W, one of a plurality of seek speeds prepared in advance is selected so that the width of the spiral pattern 13 (see FIG. 17) can secure an appropriate number of syncs. The appropriate number of syncs is the number of syncs that allows the head HD to be positioned with the required precision, and can be set to a slice level (for example, 5) or more. The disk device 1 selects one of the plurality of seek speeds that is suitable for the write width W. WEAccording to the size, the fastest seek speed among the seek speeds at which the Sync number is equal to or greater than the slice level may be selected.

[0057] The width of the spiral pattern 13 in the circumferential direction that can ensure an appropriate Sync number is obtained by calculating the 1-frame length (for 1 Sync) of the spiral pattern 13 × the appropriate Sync number. Hereinafter, the write width W WE The width of the spiral pattern 13 in the circumferential direction corresponding to twice the write width W will be referred to as the spiral width SP.

[0058] A plurality of candidate seek speeds and the corresponding write widths can be determined experimentally in advance. As shown in FIG. 12, at a certain seek speed, as the write width of the write element WE increases, the number of Syncs that can be read by the read element RE during demodulation tends to increase. FIG. 12 is a diagram showing how to determine the seek speed. In FIG. 12, the vertical axis represents the number of frames of the spiral width SP, and the horizontal axis represents the write width. The time for 1-frame length (Sync + basic Dibit) is T (sec), the seek speed during writing is V (m / sec), and the write width is W WE (nm), then the number of frames F (count) of the spiral width is obtained by the following formula 2. F=(2×W WE ×10 -9 ) / V / T ··· Formula 2

[0059] For example, prepare three types of seek speeds V1, V2, V3 that satisfy the following formula 3. V1<V2<V3 ··· Formula 3

[0060] At a relatively slow seek speed V1, as shown by the dashed line L1 in FIG. 12, as the write width W of the write element WE WE increases, the number of Syncs that can be read by the read element RE during demodulation can increase linearly.

[0061] At a relatively fast seek speed V3, as shown by the dotted line L3 in FIG. 12, the write width W WE changes in a wider range, and the write width W of the write element WEWE As the [parameter] increases, the number of Syncs that can be read by the read element RE during demodulation can increase linearly.

[0062] At a medium seek speed V2, as shown by the solid line L2 in FIG. 12, the write width W WE changes in a region where it is medium, and as the write width W WE of the write element WE increases, the number of Syncs that can be read by the read element RE during demodulation can increase linearly.

[0063] When setting the appropriate number of Syncs to be greater than or equal to the slice level, prepare three types of write widths W1, W2, W3 that satisfy the following mathematical formula 4, corresponding to the intersections of the straight lines L1 to L3 in FIG. 12 and the straight line L0 indicating the slice level. W1 < W2 < W3 ··· Mathematical formula 4

[0064] For a head HD having a relatively narrow write width W WE (for example, W1 ≤ W WE < W2), as shown by the dashed line in FIG. 12, set the seek speed when writing with the write element WE of the head HD to be a relatively slow V1, and as shown in FIG. 13, reduce the inclination angle θ1 with respect to the circumferential direction of the spiral pattern 13. The spiral width SP1 corresponding to twice the write width W [[ID=​​​​​​​​​​​​​​​​​​For the head HD having , when writing with the write element WE of the head HD, the seek speed is set to a relatively high V3, and as shown in FIG. 15, the inclination angle θ3 with respect to the circumferential direction of the spiral pattern 13 is increased. The spiral width SP3 corresponding to twice the write width W WE satisfies the following formula 6. SP3 = 2×W WE ×1 / (tanθ3) ··· Formula 6

[0067] As shown in Formula 6, by increasing the inclination angle θ3 in the case of a wide write width W WE , the length of the appropriate spiral width SP3 can be set. Thereby, it is possible to suppress deterioration of the positioning accuracy due to a decrease in the number of spiral patterns that can be demodulated when the width in the time direction of the spiral pattern demodulated by the read element RE of the head HD is too long.

[0068] For the head HD having a medium write width W WE (for example, W2 ≤ W WE < W3), when writing with the write element WE of the head HD, the seek speed is set to a medium V2, and as shown in FIG. 14, the inclination angle θ2 with respect to the circumferential direction of the spiral pattern 13 is set to medium. The spiral width SP2 corresponding to twice the write width W WE satisfies the following formula 7. SP2 = 2×W WE ×1 / (tanθ2) ··· Formula 7

[0069] As shown in Formula 7, by setting the inclination angle θ2 to medium in the case of a medium write width W WE , the length of the appropriate spiral width SP3 can be set. Thereby, an appropriate number of syncs can be ensured, and the yield of the SSW process can be improved. Also, it is possible to suppress deterioration of the positioning accuracy due to a decrease in the number of spiral patterns that can be demodulated.

[0070] Each of the spiral widths SP1 to SP3 shown in FIGS. 13 to 15 satisfies the following formula 8. SP1 ≒ SP2 ≒ SP3 ··· Formula 8 Each spiral width SP1 to SP3 becomes approximately the same by selecting seek speeds V1 to V3 according to the write width W WE and setting them as tilt angles θ1 to θ3.

[0071] Note that for a head HD having an overly narrow write width W WE (for example, 0 ≤ W WE < W1), it may be processed as an error. This can avoid writing of the spiral pattern 13 with insufficient Sync numbers.

[0072] As shown in FIG. 12, a range for determining the write width W WE may be provided. Corresponding to a relatively narrow write width W WE , a range WR1 where W1 ≤ W WE < W2 is defined. Corresponding to a medium write width W WE , a range WR2 where W2 ≤ W WE < W3 is defined. Corresponding to a relatively wide write width W WE , a range WR3 where W3 ≤ W WE is defined. Corresponding to an overly narrow write width W WE , a range WR0 where 0 ≤ W WE < W1 is defined.

[0073] If the write width W WE measured in S15 is included in the range WR1, the disk device 1 selects the seek speed V1 from among the plurality of seek speeds V1 to V3. If the write width W WE measured in S15 is included in the range WR2, the disk device 1 selects the seek speed V2 from among the plurality of seek speeds V1 to V3. If the write width W WE measured in S15 is included in the range WR3, the disk device 1 selects the seek speed V3 from among the plurality of seek speeds V1 to V3. Thereby, the seek speed can be appropriately adjusted according to the write width.

[0074] Note that if the write width W WE measured in S15 is included in the range WR0, the disk device 1 may notify it as an error and end the process.

[0075] In S16, the adjustment pattern 12 is erased. While tracking the guide spiral pattern 11, an offset is applied from the cylinder on which the adjustment pattern 12 was written, and an erase pattern is written. The frequency of the erase pattern is, for example, an AC erase pattern with a frequency four times the basic dibit of the adjustment pattern 12. The write range of the erase pattern is, for example, written 10 times in the circumferential direction. In the radial direction, an offset is applied in 0.5 track increments from the written cylinder, and a range of ±2 cylinders is written, erasing almost all of the adjustment pattern.

[0076] Returning to FIG. 1, in the BDW step (S1), tracking is performed on the guide spiral pattern 11, and a spiral pattern 13 is written at the seek speed adjusted in S4 (S5). The disk drive 1 may write a plurality of spiral patterns 13_1 to 13_6 as shown in FIG. 16 to the corresponding recording surface of the disk 10 using the head HD. FIG. 16 is a diagram showing the arrangement of the spiral patterns 13 on the disk 10. In FIG. 16, the rotation direction of the disk 10 is indicated by a dashed arrow. Each spiral pattern 13 extends in a spiral shape from the inner periphery to the outer periphery of the disk 10. Although FIG. 16 illustrates an example in which six spiral patterns 13_1 to 13_6 are written, the number of spiral patterns 13 may be one to five, or seven or more.

[0077] The disk device 1 rotates the disk 10 at a predetermined rotational speed and controls the positioning of the head HD to a fifth position on the inner periphery according to the information read from the guide spiral pattern 11_1. While rotating the disk 10 at a predetermined rotational speed, the disk device 1 causes the head HD to seek from the inner periphery to the outer periphery of the disk 10 at a seek speed of S4 and writes control information IF2 with the write element WE. As a result, the spiral pattern 13_1 is written on the disk 10 as shown in FIG.

[0078] The disk device 1 rotates the disk 10 at a predetermined rotational speed and controls the positioning of the head HD to a sixth position on the inner periphery according to the information read from the guide spiral pattern 11_1. While rotating the disk 10 at the predetermined rotational speed, the disk device 1 causes the head HD to seek from the inner periphery to the outer periphery of the disk 10 at a seek speed of S4 and writes control information IF2 with the write element WE. As a result, the spiral pattern 13_2 is written on the disk 10 as shown in FIG.

[0079] The disk device 1 rotates the disk 10 at a predetermined rotational speed, and controls the positioning of the head HD to a seventh position on the inner periphery according to the information read from the guide spiral pattern 11_2. While rotating the disk 10 at a predetermined rotational speed, the disk device 1 causes the head HD to seek from the inner periphery to the outer periphery of the disk 10 at a seek speed of S4, and writes control information IF2 with the write element WE. As a result, the spiral pattern 13_3 is written on the disk 10, as shown in FIG.

[0080] The disk device 1 rotates the disk 10 at a predetermined rotational speed, and controls the positioning of the head HD to an eighth position on the inner periphery side according to the information read from the guide spiral pattern 11_2. While rotating the disk 10 at a predetermined rotational speed, the disk device 1 causes the head HD to seek from the inner periphery side to the outer periphery side of the disk 10 at a seek speed of S4, and writes control information IF2 with the write element WE. As a result, the spiral pattern 13_4 is written on the disk 10, as shown in FIG.

[0081] The disk device 1 rotates the disk 10 at a predetermined rotational speed, and controls the positioning of the head HD to a ninth position on the inner periphery side according to the information read from the guide spiral pattern 11_3. While rotating the disk 10 at a predetermined rotational speed, the disk device 1 causes the head HD to seek from the inner periphery side to the outer periphery side of the disk 10 at a seek speed of S4, and writes control information IF2 with the write element WE. As a result, the spiral pattern 13_5 is written on the disk 10, as shown in FIG.

[0082] The disk device 1 rotates the disk 10 at a predetermined rotational speed, and controls the positioning of the head HD to a tenth position on the inner periphery side according to the information read from the guide spiral pattern 11_3. While rotating the disk 10 at a predetermined rotational speed, the disk device 1 causes the head HD to seek from the inner periphery side to the outer periphery side of the disk 10 at a seek speed of S4, and writes control information IF2 with the write element WE. As a result, the spiral pattern 13_6 is written on the disk 10, as shown in FIG.

[0083] Returning to FIG. 1, in the SSW step (S2), tracking is performed on the spiral pattern 13, and servo patterns 14 are written (S6). As shown in FIG. 17, the disk device 1 reads the spiral pattern 13 with the read element RE of the head HD, and controls the positioning of the write element WE of the head HD to an eleventh position according to the information read from the spiral pattern 13. FIG. 17 is a diagram showing a read signal of the spiral pattern 13. While rotating the disk 10 at a predetermined rotational speed, the disk device 1 writes servo patterns 14_1 to 14_7 distributed concentrically as shown by dotted lines in FIG. 18 with the write element WE of the head HD. FIG. 18 is a diagram showing the arrangement of the servo patterns 14 on the disk 10. While FIG. 18 illustrates an example in which seven servo patterns 14_1 to 14_7 are written, the number of servo patterns 14 may be one to six, or eight or more.

[0084] As a result, a plurality of concentric tracks are defined corresponding to the plurality of servo patterns 14_1 to 14_7, and the disk device 1 is manufactured on which the disk 10 including the plurality of tracks is mounted.

[0085] As described above, in the embodiment, the disk device 1 acquires information about the write width of the head HD, adjusts the seek speed of the head HD when writing a spiral pattern to the disk 10 according to the write width, and writes the spiral pattern to the disk 10 at the adjusted seek speed. This allows the tilt angle of the written spiral pattern relative to the circumferential direction to be set to an appropriate angle according to the write width, improving the manufacturing yield in the SSW process.

[0086] For example, a relatively narrow light width W WE For a head HD having this configuration, the seek speed during writing is set to a relatively slow V1, and the inclination angle θ1 is reduced to set an appropriate spiral width SP1. This ensures an appropriate number of Syncs while increasing the number of Syncs when the spiral pattern 13 is demodulated by the read element RE of the head HD (see Figure 17), improving the yield of the SSW process.

[0087] Relatively wide light width W WE For a head HD having this configuration, the seek speed during writing is set to a relatively high V3 and the inclination angle θ3 is increased to set an appropriate spiral width SP3. This prevents deterioration of positioning accuracy due to a decrease in the number of spirals that can be demodulated when the width in the time direction of the spiral pattern demodulated by the read element RE of the head HD is too long.

[0088] Medium light width W WE For a head HD with this characteristic, the appropriate spiral width SP3 can be set by setting the seek speed V2 during writing to a medium value and the tilt angle θ2 to a medium value. This ensures an appropriate number of syncs and improves the yield of the SSW process. It also prevents deterioration of positioning accuracy due to a decrease in the number of spirals that can be demodulated.

[0089] The manufacturing information IF1 held in the rack terminal RT may include information on the write width of the head HD in association with identification information of the disk device 1. In this case, the disk device 1 may obtain the information on the write width of the head HD by receiving the information on the write width of the head HD from the rack terminal RT via a communication line.

[0090] Specifically, in the disk device 1 shown in FIG. 2, the HDC 37 can send an acquisition request for acquiring information on the write width of the head HD to the rack terminal RT via the port PT, the pallet I / F 102, and the rack I / F 101. The acquisition request includes identification information for the disk device 1 and a request to acquire information on the write width of the head HD. When the rack terminal RT receives the acquisition request, it references the manufacturing information IF1 in response to the acquisition request and extracts information on the write width of the head HD from the manufacturing method IF1 using the identification information included in the acquisition request as a key. The rack terminal RT then transmits the information on the write width of the head HD. When the HDC 37 receives information on the write width of the head HD from the rack terminal RT via the rack I / F 101, the pallet I / F 102, and the port PT, it stores the information on the write width of the head HD in the nonvolatile memory 33.

[0091] In this case, in S4 of Fig. 1, instead of S11 to S14 of Fig. 5, the disk device 1 receives information about the write width of the head HD from the rack terminal RT via a communication line, and then performs the process of S15. Also, the process of S16 is omitted.

[0092] This simplifies the seek speed adjustment process (S4), and reduces the time required to manufacture the disk device 1.

[0093] Alternatively, the write width of the head HD may change depending on the write conditions. In this case, the disk drive 1 may write the adjustment pattern 12 under different write conditions, and select a combination of write conditions and seek speed that results in an appropriate number of Sync detections.

[0094] Specifically, in S12 of FIG. 5, the disk drive 1 writes a plurality of adjustment patterns 12 corresponding to a plurality of write conditions onto the disk 10. The plurality of write conditions may have different overshoots of the write current. The overshoot indicates the magnitude of the current amplitude that swings beyond the steady-state amplitude (DC amplitude) in the waveform of the write current. The plurality of adjustment patterns 12 may be written on different recording surfaces by different heads HD.

[0095] After S13 in FIG. 5 is performed in the same manner as in the embodiment, in S14 in FIG. 5, the disk device 1 measures the readable offset range (=write width) for each of the multiple adjustment patterns 12 corresponding to the multiple write conditions. The readable offset range can also be rephrased as the radial position range in which the adjustment pattern 12 can be read. In S14, measurement results are obtained for multiple combinations of write conditions and seek speeds. The number of combinations is equal to (the number of write conditions) x (the number of types of seek speeds).

[0096] In S15 of FIG. 5, the disk device 1 selects the write width W WE Depending on the size of the sync, a combination of write conditions and seek speed is selected that will result in a width of spiral pattern 13 (see FIG. 16) that can ensure an appropriate number of syncs. From among the multiple combinations, the disk device 1 may select the fastest seek speed that results in the number of sync detections equal to or greater than the slice level.

[0097] This allows the angle of inclination of the spiral pattern to the circumferential direction to be set to an appropriate angle depending on the write width and write conditions, further improving the manufacturing yield in the SSW process.

[0098] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0099] 1 disk device, 10 disk, 11, 11_1 to 11_3 guide spiral patterns, 12 adjustment pattern, 13, 13_1 to 13_6 spiral patterns, 14, 14_1 to 14_7 servo patterns.

Claims

1. Acquiring head write width information; adjusting a seek speed of the head when writing a spiral pattern onto a disk in accordance with the obtained write width; A method for manufacturing a disk device comprising:

2. Obtaining the information includes: receiving information about the write width of the head from a system that manages the disk device via a communication line. The method for manufacturing the disk device according to claim 1 .

3. Obtaining the information includes measuring a write width of the head. The method for manufacturing the disk device according to claim 1 .

4. adjusting the seek speed setting a seek speed of the head during writing to a first speed in response to the acquired write width being a first write width; setting a seek speed of the head during writing to a second speed slower than the first speed in response to the acquired write width being a second write width narrower than the first write width; Contains The method for manufacturing the disk device according to claim 1 .

5. The measuring step comprises: writing an adjustment pattern in a circumferential direction on the disk; checking a radial position range in which the adjustment pattern can be read; Contains The method for manufacturing the disk device according to claim 3 .

6. the adjustment pattern includes a plurality of sync marks, examining the range of locations The adjustment pattern is read while offsetting the radial position of the second head relative to the disk from the track center, and an offset range in which the number of sync marks included in the read signal exceeds a first threshold is obtained. The method for manufacturing the disk device according to claim 5 .

7. adjusting the seek speed and determining a width of a spiral pattern corresponding to a distance twice the offset range for a plurality of candidate seek velocities, and selecting a seek velocity from the plurality of candidate seek velocities such that the number of frames included in the width is greater than a second threshold value. The method for manufacturing the disk device according to claim 6 .

8. Selecting the candidate seek speeds includes: and selecting the fastest seek speed from one or more seek speed candidates among the plurality of seek speed candidates, the number of frames included in the width being greater than a second threshold value. The method for manufacturing the disk device according to claim 7 .

9. The measuring step comprises: and further comprising erasing the adjustment pattern. The method for manufacturing the disk device according to claim 5 .

10. The measuring step comprises: writing adjustment patterns in a circumferential direction of the disk under a plurality of write conditions; checking a radial position range in which the adjustment pattern can be read for each of the plurality of write conditions; Including, examining the range of locations reading the adjustment pattern while offsetting a radial position of a second head from a track center with respect to the disk, and determining an offset range in which the number of sync marks included in a read signal exceeds a first threshold for each of the plurality of write conditions; adjusting the seek speed and determining a width of a spiral pattern corresponding to a distance twice the offset range for a plurality of candidate seek speeds, and selecting a combination of a seek speed and a write condition from the plurality of candidate seek speeds such that the number of frames included in the width is greater than a second threshold value. The method for manufacturing the disk device according to claim 3 .

11. The disk and an actuator for causing a head to seek relative to the disk; a controller that acquires information about the write width of the head and adjusts the seek speed of the head when writing the spiral pattern to the disk according to the acquired write width; A disk device comprising:

12. The controller The information on the write width of the head is received from a system that manages the disk device via a communication line. The disk device according to claim 11.

13. The controller The information is obtained by measuring the write width of the head. The disk device according to claim 11.

14. The controller The seek speed of the head during writing is set to a first speed when the acquired write width is a first write width, and the seek speed of the head during writing is set to a second speed slower than the first speed when the acquired write width is a second write width narrower than the first write width, thereby adjusting the seek speed. The disk device according to claim 11.

15. The controller An adjustment pattern is written in the circumferential direction of the disk, and the write width of the head is measured by checking the radial position range in which the adjustment pattern can be read. The disk device according to claim 13.

16. the adjustment pattern includes a plurality of sync marks, The controller The adjustment pattern is read while offsetting the radial position of the second head relative to the disk from the track center, and the position range is determined by determining the offset range in which the number of sync marks included in the read signal exceeds a first threshold value.

16. The disk device according to claim 15.

17. The controller The width of a spiral pattern corresponding to a distance twice the offset range is obtained for a plurality of seek speed candidates, and a seek speed candidate from the plurality of seek speed candidates in which the number of frames included in the width is greater than a second threshold is selected and set as the seek speed, thereby adjusting the seek speed.

17. The disk device according to claim 16.

18. The controller The seek speed candidate is selected by selecting the fastest seek speed candidate from one or more seek speed candidates that make the number of frames included in the width greater than a second threshold value and setting the fastest seek speed candidate as the seek speed.

18. The disk device according to claim 17.

19. The controller erases the adjustment pattern.

16. The disk device according to claim 15.

20. The controller writing an adjustment pattern in a circumferential direction of the disk under a plurality of write conditions, and measuring a write width of the head by examining a radial position range in which the adjustment pattern can be read for each of the plurality of write conditions; the adjustment pattern is read while offsetting the radial position of the second head from a track center with respect to the disk, and the position range is determined by determining an offset range in which the number of sync marks included in the read signal exceeds a first threshold value for each of the plurality of write conditions; A width of a spiral pattern corresponding to a distance twice the offset range is obtained for a plurality of candidate seek speeds, and a combination of a seek speed and a write condition is selected from the plurality of candidate seek speeds such that the number of frames included in the width is greater than a second threshold value. The disk device according to claim 13.

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