KR100496180B1 - Defect Handling on Hard Disk Drives - Google Patents

Abstract

end. The technical field to which the invention described in the claims belongs:

It is a technology related to the hard disk drive manufacturing process.

I. The technical problem the invention is trying to solve:

It provides a way to handle radial defects in hard disk drives.

All. The gist of the solution of the invention:

According to the present invention, when a radial scratch along a sector boundary is detected, a sector having a large scratch density is first defected, and an adjacent sector having a low scratch density is also defected.

la. Important uses of the invention:

Defect Processing on Hard Disk Drives

Description

Defect Handling on Hard Disk Drives

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to magnetic disk drives, and more particularly, to a method of processing defecs generated on a disk during a manufacturing process of a hard disk drive (hereinafter referred to as "HDD").

These days, data storage and reading devices are rapidly increasing in capacity in response to the multimedia implementation of the system, and are being developed to enable high-speed data access. One example of such a data storage and reading device is a hard disk drive (HDD). The HDD is widely used as an auxiliary memory device of a computer system due to the advantage of enabling high-speed data access and high capacity.

The HDD is shipped as a complete product through a series of manufacturing process procedures as shown in FIG. 1 is a diagram illustrating a general main procedure in the HDD manufacturing process, which is divided into six stages.

Referring to each step with reference to Figure 1, first, the first step (I) of the manufacturing process HDA (Head Disk Assembly) assembly process is a process of assembling the head disk assembly (HDA) of the HDD of the manufacturing process clean ( in the room. In the second step (II) of the manufacturing process, a servo writer writes a servo pattern for servo control of a magnetic head that reads and writes data to a disk, which is a recording medium, by a servo writer. Is performed. The function test, which is the third step (III) of the manufacturing process, combines the HDA made in the HDA assembly process with the PCBA made in the printed circuited board assembly (PCBA) assembly process (usually performed after the HDA assembly process). This is the first test that is done to test if the HDA and PCBA work correctly. The burn-in test process, which is the fourth stage (IV) of the manufacturing process, takes the longest time (normally 8 hours to 16 hours) of the HDD manufacturing process. It is placed on a rack in a high humidity burn-in room and then performed according to its own program (firmware). In this burn-in test process, the defect part existing on the disk is found in advance in order to allow the consumer to use the HDD normally, and a process of preempting the defect part when the actual drive is used. The final test process, which is the fifth step (V) of the manufacturing process, is a process for checking whether the HDD set passed in the burn-in test process is normally defected. Test the defect state for each set. After the final test process, the HDD set is shipped as a finished product through the shipment inspection process, packaging and shipment process, which is the sixth step (VI) of the manufacturing process.

As mentioned with reference to FIG. 1, a HDD is produced in several steps, and a servo defect and a data defect are inspected through a process called a burn-in test. After this process, the system is reassigned for use and a series of tests related to the drive's performance is performed.

The burn-in test process defect processing in the prior art reduces defects in the radial direction of the disc by defecting a few pieces to each side of the defect sector detected using a predetermined algorithm or the like to reduce the occurrence of additional errors. In the case of circumferential defects, defected sectors are treated as defects to reduce the occurrence of additional errors. The reason why the defect in the circumferential direction is to defect only the defected sector is that if the defecting process is performed both before and after the defected sector, too many defects are generated on the disc.

However, in the conventional defect processing method, when a radial defect, particularly a radial scratch occurs at a sector and a sector boundary shown in FIG. 3, a defect may not be found during the defect scanning process. 3 shows that scratches 50 are generated in the radial direction along the boundary between the third sector 3S and the fourth sector 4S of the 1,2,3 track. In such a case, adjacent sectors may grow into defects due to scratches occurring radially along the sectors and sector boundaries in a later process or in a user environment.

Accordingly, an object of the present invention is to provide a method for dealing with a defect for a scratch occurring along a sector and a sector boundary in a hard disk drive.

In accordance with the above object, the present invention provides a method for processing a defect of a hard disk drive.

A first step of detecting a defect in which a radial scratch along a sector boundary is generated during the defect scanning;

A second process of defecting a sector having a high specific gravity of the scratch;

And a third process of defecting an adjacent sector having a low specific gravity after the second process.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same elements in the figures are denoted by the same numerals wherever possible. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

FIG. 2 shows a general block diagram of a HDD completed through the manufacturing process of FIG. 1. Referring to FIG. 2, the disks 10 are rotated by a spindle motor 34. Each of the heads 12 is located on the corresponding one of the disks 10, and the disks 10 from the E-block assembly 14 coupled with the rotary voice coil actuator 30. It is installed to correspond to each of the support arms extending to the side. The preamplifier 16 preamplifies the signal picked up by one of the heads 12 at the time of read, and applies the analog read signal to the read / write channel circuit 18. The coded write data applied from the read / write channel circuit 18 is written onto the disc through the corresponding one of the heads 12. The read / write channel circuit 18 detects and decodes a data pulse from the read signal applied from the preamplifier 16 and applies the read / write channel circuit 18 to the DDC (Disk Data Controller) 20, and writes the write data applied from the DDC 20. Decode and apply to preamplifier 16. The DDC 20 writes data received from the host computer via the read / write channel circuit 18 and the preamplifier 16 to the disk or reads data from the disk and transmits the data to the host computer. The DDC 20 also interfaces the communication between the host computer and the microcontroller 24. The buffer RAM 22 temporarily stores data transmitted between the host computer and the microcontroller 24 and the read / write channel circuit 18. The microcontroller 24 controls track search and track following in response to a read or write command received from the host computer. The memory 26 stores the execution program of the microcontroller 24 and various setting values. The servo driver 28 generates a driving current for driving the actuator 30 in response to a signal for controlling the position of the heads 12 provided by the microcontroller 24 and applies it to the voice coil of the actuator 30. do. The actuator 30 moves the heads 12 on the disks 10 in correspondence with the direction and level of the drive current applied from the servo driver 28. The spindle motor driver 32 rotates the disks 10 by driving the spindle motor 34 according to a control value for the rotation control of the disks 10 generated from the microcontroller 24.

The burn-in test process in the HDD manufacturing process is implemented using test equipment to be configured as the HDD of the finished product as shown in FIG. Therefore, an embodiment of the burn-in test process according to the embodiment of the present invention will be described with reference to the HDD general block configuration of FIG. 2.

FIG. 4 is a flowchart of a defect processing according to an embodiment of the present invention, and when detecting a radial scratch along a sector boundary, it is summarized that the sector having a large scratch weight is first defected and the adjacent sector having a low scratch weight is also defected. .

Hereinafter, a method for processing a defect in accordance with an embodiment of the present invention will be described in more detail with reference to FIGS. 2 to 4. When the microcontroller 24 of FIG. 2 detects a radial scratch along a sector boundary in step 100 of FIG. 4 during the de-scan during the burn-in test process, the microcontroller 24 proceeds to step 102 and first defects a sector having a large scratch density. The process proceeds to step 104 and defects adjacent sectors with a low scratch ratio and ends the process. For example, in FIG. 3, when the third sector 3S of the 1,2,3 track has a large scratch ratio, the third sector 3S is defected first, and then the adjacent sector having the low scratch ratio, that is, the fourth sector 4S, is also defected.

As described above, in the present invention, when a radial scratch along a sector boundary is detected, a sector having a large scratch density is first defected and an adjacent sector having a low scratch density is also defected.

1 is a manufacturing process flow chart for explaining the manufacturing process steps of a conventional hard disk drive (Hard Disk Drive),

2 is a block diagram of a hard disk drive for explaining an embodiment of the present invention;

3 is a diagram showing radial scratches generated along a sector and a sector boundary;

4 is a defect processing flowchart according to an embodiment of the present invention.

Claims (1)

In the method for processing a defect in a hard disk drive, A first step of detecting a defect in which a radial scratch along a sector boundary is generated during the defect scanning; A second process of defecting a sector having a high specific gravity of the scratch; And a third process of defecting an adjacent sector having a low specific gravity after the second process.

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