KR100714879B1 - Hard disk drive, method for scanning defect of disk of the hard disk drive, and recording media for computer program therefor - Google Patents

Abstract

Disclosed are a hard disk drive, a defect detection method of a hard disk drive, and a recording medium on which a computer program for performing the method is recorded. The defect detection method of the hard disk drive of the present invention includes: (a) performing a defect scan on a disk to be inspected to determine whether the defect is based on a plurality of different defect reference values; (b) generating a plurality of temporary defect lists corresponding to the plurality of defect reference values based on the information of the sector detected as defect for each defect reference value; And (c) selecting, from the plurality of temporary defect lists, a temporary defect list suitable for a preset criterion as the final defect list. According to the present invention, by detecting defects with respect to a plurality of defect reference values, the defects of the disk can be detected more precisely than the conventional method without lowering the production efficiency, thereby improving the reliability of the hard disk drive. Can be improved.

Hard Disk Drive, Defect, Defect Threshold

Description

Hard disk drive, method for scanning defect of disk of the hard disk drive, and recording media for computer program therefor}

1 is an exploded perspective view illustrating a configuration of a hard disk drive according to an embodiment of the present invention.

FIG. 2 is a schematic diagram schematically showing a configuration of a disk included in the hard disk drive of FIG. 1.

3 is a schematic block diagram of a driving circuit of the hard disk drive of FIG. 1.

4 is a flowchart of a manufacturing process of the hard disk drive of FIG. 1.

5 is a flowchart illustrating a defect detection method of the hard disk drive of FIG. 1.

   5A illustrates a defect detection process.

   5B illustrates a final defect list selection process.

6 is a graph showing the number of defect detections according to the change of the defect reference value.

Explanation of symbols on the main parts of the drawings

110: disc 111: track

112: sector 120: spindle motor

131: magnetic head 135: actuator

170: controller 171: preamp

172: lead / light channel 173: host interface

174: buffer memory

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard disk drive, a method for detecting a defect of a hard disk drive, and a recording medium on which a computer program for performing the method is recorded. The present invention relates to a hard disk drive capable of detecting a defect and, accordingly, a method of detecting a defect of a hard disk drive and a recording medium on which a computer program for performing the method can be recorded.

A hard disk drive (HDD) is a data storage device that converts a digital electronic pulse including data information into a permanent magnetic field to record to or play back data recorded on the disk. Such a hard disk drive has been utilized as a representative auxiliary storage device of a computer system because of the advantage of being able to record and reproduce a large amount of data at high speed.

Generally, a disk of a hard disk drive has a defect in terms of material itself, or a defect may be generated by various factors during the production process of the hard disk drive. For example, during a process of assembling a hard disk drive, a disk may be damaged by a scratch during the loading of a head stack assembly onto a disk, or a servo pattern may be applied to a magnetic head. Defects may occur on the disk due to a defect in the servo pattern itself during the recording process.

In particular, in recent years, in order to realize high track per inch (TPI) and bit per inch (BPI), tracks and sectors are formed more densely, and thus the possibility of defects has become a negligible factor.

The defect of such a disk not only can not record data in the sector where the defect has occurred, but also causes a problem that even recorded data cannot be reproduced again.

As a solution to this, by storing information about the sector where the defect was detected and mapping the sector where the defect was detected, it prevents the user from using the sector and thus prevents valuable data from being lost. Therefore, during the manufacturing process of the hard disk drive, a process of detecting whether there is a defect in the sector of the disk and storing information on the sector where the defect is detected is essential.

The conventional defect detection method mainly uses a method of determining whether or not a defect exists in a corresponding sector by recording predetermined data on a disk and comparing the magnitude of a signal generated when the data is reproduced with a preset reference value. I use it.

However, such a conventional defect detection method unilaterally applies only one reference value without considering the difference in the material of each disc, so that data stored in a sector that has not been detected as a defect may not be properly read in the future. There was a problem that the possibility of lowering the reliability. That is, some discs detect only a very small number of defects with respect to one reference value, and some discs detect a significantly larger number of defects with a reference value that is slightly more stringent than the reference value. There is a problem that the reliability of the disk may be degraded by detecting defects uniformly by applying only one reference value without considering the differences between the disks.

Accordingly, an object of the present invention is to detect the defect of a disc more precisely than before, without degrading the production efficiency, thereby improving the reliability of the hard disk drive and the hard disk drive. It is to provide a defect detection method and a recording medium on which a computer program for performing the method is recorded.

According to the present invention, (a) performing a defect scan on the disk of the inspection object to determine whether the defect based on a plurality of different reference values different from each other; (b) generating a plurality of temporary defect lists corresponding to the plurality of defect reference values based on the information of the sector detected as defect for each defect reference value; And (c) selecting, from among the plurality of temporary defect lists, a temporary defect list suitable for a predetermined criterion as a final defect list. This is achieved by a recording medium which records a computer program to be executed.

In this case, the plurality of defect reference values may be a drop out defect reference value for determining whether a signal detected during a defect scan is smaller than a predetermined reference.

Here, the plurality of defect reference values may include an upper reference value, an intermediate reference value, and a lower reference value divided according to the severity of the level recognized as the defect sector.

The step (c) is preferably a step of selecting, as a final defect list, a temporary defect list in which a plurality of defect sector information, which is smaller than a preset limit value, is stored among information of a plurality of temporary defect lists. .

Here, the threshold value is preferably a reference value for defective processing of the disk when the number of defect sectors as a result of defect detection of the disk is larger than the threshold value.

The plurality of temporary defect lists are preferably stored in the maintenance cylinder.

Also, the final defect list is preferably stored in the buffer memory.

On the other hand, the object is, according to the present invention, at least one disk; A magnetic head for detecting a signal by writing predetermined data to a disc and reading the data; And a defect scan of the disc to determine whether the defect is based on a plurality of different defect reference values, and a plurality of defects based on the information detected by the defect for each defect reference value. And a controller for creating a plurality of temporary defect lists corresponding to the reference value and selecting a temporary defect list suitable for a preset criterion among the plurality of temporary defect lists as the final defect list. Is also achieved.

In this case, the plurality of defect reference values may be a drop out defect reference value for determining whether a signal detected during a defect scan is smaller than a predetermined reference.

Here, the plurality of defect reference values may include an upper reference value, an intermediate reference value, and a lower reference value divided according to the severity of the level recognized as the defect sector.

The controller may select, from the plurality of temporary defect lists, a temporary defect list in which information of the largest number of defect sectors is stored as smaller than a preset limit value as the final defect list.

Here, the threshold value is preferably a reference value for defective processing of the disk when the number of defect sectors as a result of defect detection of the disk is larger than the threshold value.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing the present invention, description of already known functions or configurations will be omitted to clarify the gist of the present invention.

1 is an exploded perspective view showing the configuration of a hard disk drive according to an embodiment of the present invention, Figure 2 is a schematic diagram showing the configuration of a disk provided in the hard disk drive of Figure 1, Figure 3 4 is a schematic block diagram of a drive circuit of the hard disk drive of FIG. 1, FIG. 4 is a flowchart of a manufacturing process of the hard disk drive of FIG. 1, and FIG. 5 is a flowchart of a defect detection method of the hard disk drive of FIG. a) shows a defect scanning process, b) of FIG. 5 shows a final defect list selection process, and FIG. 6 is a graph showing the number of defect detections according to the change of the defect reference value.

As shown in FIG. 1, the hard disk drive 100 according to an exemplary embodiment of the present invention may include at least one disk 110 on which data is recorded, and a spindle motor configured to rotationally drive the disk 110. 120, a spindle motor, a head stack assembly (HSA) that moves on the disk 110 by pivoting the pivot shaft (130a) axially, and a controller as described below, most of the circuit components. A printed circuit board assembly (PCBA) 140 mounted on a printed circuit board (PCB) to control these components, and a base 150 on which these components are assembled. And a cover 160 covering the upper part of the base 150 to seal these components from external dust and foreign matters.

One or more disks 110 may be provided. When a plurality of disks 110 are provided, the disks 110 are stacked on the base 150 spaced apart from each other by a predetermined distance. Both sides of the disk 110 are coated with a thin film of magnetic material, where data is stored. The magnetic material is coated on the face of the disk 110 by methods such as electroplating, sputtering, chemical vapor deposition, physical vapor deposition, and the like.

The size of the disk 110 may be 1.0 inch, 1.8 inch, 2.5 inch, 3.5 inch, 5.25 inch, 8 inch and 14 inch, but the scope of the present invention is not limited thereto. The material of the disk 110 may be aluminum alloy, glass, glass composite and magnesium alloy, but the scope of the present invention is not limited thereto.

The disk 110 has a large number (substantially hundreds of thousands) of tracks 111 formed of a plurality of concentric circles, as shown in FIG. The track 111 refers to concentric circles formed on one disk 110. Since the hard disk drive 100 is generally used by stacking a plurality of disks 110, the tracks formed on each of the plurality of disks 110 are used. It is often convenient to use the term cylinder 111 to mean a set of tracks 111 having the same radius among the 111. That is, the cylinder 111 may be interpreted as connecting virtual tracks 111 having the same radius to a plurality of disks 110, but may have the same physical meaning as the track 111. FIG. have.

Each track 111 has a plurality of sectors 112, including a servo sector 112a and a data sector 112b. The servo sector 112a includes servo information including a gray code that is unique information for each track 111 of the disc 110 and a burst that is comparison information for an on track of the magnetic head 131. The data sector 112b includes 512 bytes of substantial user data and an error correction code (ECC) for correcting minute errors of the data.

As illustrated in FIG. 2, the disk 110 may be largely divided into a system area A, a data area B, and a parking area C. As shown in FIG.

The system area A refers to a maintenance area, and includes various system information and information for maintenance of the hard disk drive 100. More specifically, in the system area A, a defect list in which the unique number of the hard disk drive 100, the relevant information during the manufacturing process, the information on the defect sector detected by the defect scan, and the like are recorded. List) and SMART (Self Monitoring Analysis Reporting Technology) information.

The data area B occupies most of the surface of the disk 110 and records servo information (for example, a servo pattern), substantial user data information, and the like.

As illustrated in FIG. 3, the hard disk drive 100 according to the exemplary embodiment of the present invention may include a preamplifier 171, a read / write channel 172, a host interface 173, and the like. , The buffer memory 174, the voice coil motor driver 136, the spindle motor driver 122, and the controller 170 controlling them.

The controller 170 controls the mechanical and electrical operations of the hard disk drive 100, and may be a digital signal processor (DSP), a microprocessor, a microcontroller, or the like. It may also be implemented in software or firmware. In addition, the controller 170 includes a buffer memory 174 such as a read only memory (ROM) or a random access memory (RAM) such as a flash memory. This buffer memory 174 records the final defect list as described below, so as not to access the defect sectors when using the hard disk drive.

The controller 170 adaptively detects defect sectors based on a plurality of defect reference values in detecting defects of the disc 110 in a burn-in process as will be described later. By storing a temporary defect list corresponding to the defect reference value, selecting a temporary defect list including the largest number of defect sectors as the final defect list while satisfying a preset criterion among the temporary defect lists. Therefore, the reliability of defect detection can be improved. A detailed description thereof will be described later in parallel with the description of a defect detection method S100 of a hard disk drive according to an exemplary embodiment.

Data is reproduced and recorded by the data reproduction mode and the data recording mode. In the data read mode, the data signal reproduced from the disc 110 by the magnetic head 131 is amplified by the preamplifier 171 and converted into a digital signal by the read / write channel 172. Thereafter, the controller 170 is transmitted to the host interface 172 through the controller 170 and output to the host device (not shown). In the data write mode, the user's input data input from the host device and received by the host interface 173 is input to the read / write channel 172 through the controller 170 to facilitate recording. The data is converted into a full data stream, and amplified to a write current by the preamplifier 171 and recorded on the disc 110 by the magnetic head 131.

On the other hand, the manufacturing process of the hard disk drive according to an embodiment of the present invention, as shown in Figure 4, the mechanism assembly process (S10), the servo write (Servo Write) process (S20), function test (Function Test) The process (S30), burn-in (Burn-in) (S40), the final test (Final Test) process (S50) and shipping inspection, packaging and shipping process (S60).

The instrument assembly process S10 refers to a process of assembling a head disk assembly (HDA), which is an assembly of components of the hard disk drive 100.

The servo write process S20 refers to a process of recording servo information (eg, a servo pattern) for servo control of the actuator 135 by a servo writer.

The functional test process (S30) is a process performed after coupling the head disk assembly (HDA) and the printed circuit board assembly (PCBA) to each other. The function test process (S30) is a process of testing whether the hard disk drive 100 is mechanically and electrically operated normally. it means.

Burn-in process (S40) is the longest process in the manufacturing process of the hard disk drive 100, and itself on a rack in a burn-in room without a separate test system The process of detecting the defect of the disk 110 by a program (software or firmware). Defect detection method (S100) of the hard disk drive 100 according to an embodiment of the present invention, in the burn-in process (S40) in accordance with a plurality of defect reference values to create a plurality of temporary defect list In this case, the reliability of the defect detection is improved by selecting a temporary defect list that meets a preset criterion among the temporary defect lists and stores the largest number of defect sectors as the final defect list. It will be described later.

The burn-in process S40 performs a recording and reproducing test with the magnetic head 131 on the entire area of the disk 110 surface in order to detect the defect of the disk 110 surface. In this recording and reproducing test process, the magnitude of the signal detected during reproducing is compared with a preset defect reference value to determine whether the corresponding sector is a defect sector. Defect sectors detected corresponding to a plurality of defect reference values are temporarily stored in the maintenance cylinder A as a temporary defect list, and as described below, a list meeting the criteria is selected as the final defect list. The hard disk drive 100 is provided which is stored in the buffer memory 174 and is subsequently deemed virtually defect free to the user, thereby avoiding accessing the address of the defect sector in the user environment.

The final test process S50 refers to a process of finally checking whether the defect of the disk 110 is normally processed and the hard disk drive 100 is normally operated.

After completion of the final test process (S50), the hard disk drive is shipped as a finished product through the shipment inspection, packaging and shipping process (S60).

Hereinafter, a defect detection method of a hard disk drive according to an embodiment of the present invention will be described in detail.

First, the concept of the defect in the hard disk drive 100 will be briefly described as follows. The defect is generally due to the difference in thickness of the thin film or the influence of particles of the material of the disk 110 when the magnetic material is applied to the disk 110 of the hard disk drive 100. If the signal detected during playback of the data after recording the data on the computer is too small (Drop Out), the signal is too large (Drop In), and the signal detected during playback due to thermodynamic problems has a predetermined offset. As such, it may be classified into a case detected in the eccentric region (Thermal Aspect).

In all three cases, it can be seen that there is a defect in the sector. First, when the signal is too small (Drop Out), the defect means when the signal to be detected is smaller than the preset Drop Out Defect Criteria. When the signal is too large (Drop In), the defect means when the signal to be detected is larger than the preset Drop In Defect Criteria, and when the signal is detected in the eccentric region (Thermal Aspect) Defect of means when the average value of the detected signal is detected in the eccentric region by an offset larger than the preset offset reference value (Offset Criteria). Hereinafter, a method of detecting a defect when the signal is too small (Drop Out) among the three cases of defects will be described as an example. That is, if the magnitude of the signal detected in the sector is larger than the dropout defect reference value, the sector is a good sector. If the signal is smaller than or equal to the dropout defect reference value, the sector is determined to be a defect sector.

As shown in FIG. 5A, in order to detect a defect of the hard disk drive 100 according to an exemplary embodiment of the present invention, the magnetic head 131 may include a disk 110 of the hard disk drive 100. In step S120, signals are detected (S110), and an average value Avg of the detected signals is obtained (S120). The average value Avg of the signals is compared with the upper reference value Max among the plurality of defect reference values (S130). The upper reference value Max corresponds to the strictest degree among the upper reference value Max, the middle reference value Med, and the lower reference value Min obtained by dividing a plurality of defect reference values according to the severity of defect detection.

If the average value Avg of the signals is larger than the upper reference value Max (Y), the sector is regarded as a sector where no defect is detected because it is a very good sector, and the defect scan of the next sector is performed (S170). ). On the other hand, if the average value Avg of the signals is less than or equal to the upper reference value Max (N), the information of the corresponding sector (for example, the address of the sector) is recorded in the first cylinder of the maintenance cylinder A, A first temporary defect list is created (S131). In this case, it is preferable to repeat the test S132 several times in order to increase the reliability of the result, whether the average value Avg of the signals is less than or equal to the upper reference value Max.

After recording the information of the sector (S131), the average value (Avg) of the signals in the sector is compared with the intermediate reference value (Med) among the plurality of defect reference values (S140). This intermediate reference value Med has a medium stringency among the plurality of defect reference values.

If the average value Avg of the signals is greater than the intermediate reference value Med (Y), the process proceeds to the defect scan of the next sector (S170). On the other hand, if the average value (Avg) of the signals is less than or equal to the intermediate reference value (Med) (N), the information of the sector is recorded in the second cylinder of the maintenance cylinder to create a second temporary defect list (S141). . In this case, it is preferable to repeat the test S142 several times in order to increase the reliability of the result, whether the average value Avg of the signals is less than or equal to the intermediate reference value Med.

After the information of the sector is recorded (S141), the average value Avg of the signals in the sector is compared with the lower reference value Min among the plurality of defect reference values (S150). This lower reference value Min has a low degree of stringency among the plurality of defect reference values.

If the average value Avg of the signals is greater than the lower reference value Min (Y), the process proceeds to the defect scan of the next sector (S170). On the other hand, if the average value Avg of the signals is less than or equal to the lower reference value Min (N), the information of the corresponding sector is recorded in the third cylinder of the maintenance cylinder A, and a third temporary defect list is created. (S151). In this case, it is preferable to repeat the test S152 several times in order to increase the reliability of the result, whether the average value Avg of the signals is less than or equal to the lower reference value Min.

This process is described as an example. Assuming that the average value Avg of the signals of the first sector is 71.5%, the upper reference value Max is 73.4%, the intermediate reference value Med is 72.0%, and the lower reference value Min is 70.3%, Since the average value Avg of the signals of S is smaller than the upper reference value Max, the information of the first sector is recorded in the first temporary defect list (S131). In addition, since the average value Avg of the signals of the first sector is smaller than the intermediate reference value Med, the information of the first sector is also recorded in the second temporary defect list (S141). Since the average value Avg of the signals of the first sector is larger than the lower reference value Min, the average value Avg is not recorded in the third temporary defect list, and the defect scan for the second sector is performed 170.

Assuming that the average value Avg of the signals of the second sector is 69%, the information of the second sector is written to the first temporary defect list because the average value Avg of the signals of the second sector is smaller than the upper reference value Max. (S131). Further, since the average value Avg of the signals of the second sector is smaller than the intermediate reference value Med, the information of the second sector is also recorded in the second temporary defect list (S141). Finally, since the average value Avg of the signals of the second sector is smaller than the lower reference value Min, it is also recorded in the third temporary defect list (S151).

 In this way, the first to third temporary defect lists are generated by comparing the average value Avg of the signals for all sectors of the disk 110 with the upper reference value Max, the middle reference value Med, and the lower reference value Min. It is.

After the defect sector is recorded up to the third temporary defect list (S151), before the defect scan of the next sector is performed (S170), the threshold number of defect sectors recorded in the third temporary defect list is preset. It is compared with (Criteria) (S160). When the number of defect sectors recorded in the third temporary defect list is larger than the preset threshold (Y), the disc 110 performs a defective process (S161). That is, if there are more defect sectors than the preset limit even when compared to the lower reference value Min applied the lowest degree of severity, a much larger number of defect sectors will be applied if the higher degree of severity is applied. Will be found, so it is determined that the disk 110 is not reliable.

In this case, the threshold is a value that is optimized to adequately satisfy the yield and reliability of the hard disk drive 100, and different values are generally applied as necessary for each production company. That is, in order to increase the output of the hard disk drive 100, the lower limit may be lowered, so that the reliability may be slightly reduced, but a large amount of the disk 110 may be produced, and the upper limit may be increased in order to increase the reliability of the hard disk drive 100. By doing so, the output is slightly reduced, but the disk 110 can be produced with high reliability. Therefore, regardless of the numerical value of the limit value, all kinds of limit values will be said to belong to the scope of the present invention.

By repeating the above processes S110 to S170 for all sectors of the disc 110, after the first temporary defect list to the third temporary defect list are created, as shown in FIG. 5B. As shown, the process proceeds to the defect free process. Defect-free process is to select the final defect list to be finally stored in the buffer memory 174, so that when the user uses the hard disk drive 100, the defect sector is considered intact to the user by not accessing the defect sector. It means a process to be able to provide the hard disk drive 100.

Accordingly, the number of defect sectors recorded in each temporary defect list is compared with a preset limit value (S180), so that the largest number of defects among the temporary defect lists in which the number of defect sectors not exceeding the limit value are recorded. The temporary defect list in which the sector is recorded is selected as the final defect list (S190). For example, assume that 3000 defect sectors are recorded in the first temporary defect list, 2,000 defects in the second temporary defect list, and 1,000 defect sectors in the third temporary defect list, and the limit is 2,500 defect sectors. If the second temporary defect list and the third temporary defect list do not exceed the limit, the number of defect sectors is recorded. Among them, the second temporary defect list in which the larger number of defect sectors is recorded is recorded. The final defect list is selected.

With reference to FIG. 6 and Table 1, it demonstrates in detail as follows.

Threshold Temporary Defect List 2nd temporary defect list Third Temporary Defect List  8,000 4,715 (selected)  2,104  1,273  4,000  4,715 2,104 (choice)  1,273  2,000  4,715  2,104 1,273 (choice)

As compared to FIG. 6 and Table 1, if the upper reference value is set to 73.4%, the middle reference value to 72.0%, and the lower reference value to 70.3% in advance, the defect is detected with respect to the upper reference value and recorded in the first temporary defect list. 4,715 detected defects are detected as defects on the intermediate reference value and recorded in the second temporary defect list. 2,104 defect sectors are detected as defects on the intermediate reference value and recorded in the third temporary defect list. The number of defect sectors added is 1,273.

At this time, if the threshold for determining whether the disk 110 is defective is set to 8,000 in advance, since the first to third temporary defect lists all satisfy the threshold, the largest number of defect sectors among them are determined. If the recorded first temporary defect list is selected as the final defect list, the highest reliability can be obtained within a range that does not lower the output of the hard disk drive.

If the threshold value is preset to 4,000, the second temporary defect list will be selected as the final defect list, and if the threshold value is preset to 2,000, the third temporary defect list will be selected as the final defect list.

That is, according to the defect detection method (S100) of the hard disk drive according to an embodiment of the present invention, the threshold value may be adjusted to suitably satisfy two factors, namely, production and reliability, as necessary. Since the defect list can be determined, reliability can be improved without lowering the process efficiency.

The final defect list selected through the above process is recorded in the buffer memory 174 so that the corresponding sector may not be accessed when the hard disk drive is used, so that the hard disk may be regarded as a defect to the user. It is possible to provide the drive 100.

In the above-described embodiment, only the process of comparing the defect when the detected signal is too small (Drop Out) with the dropout defect reference value is described as an example. However, when the detected signal is too large (Drop In), The same applies to the case where the defect is compared with the drop in defect reference value or when the defect is detected in an area eccentric by an offset that is too large. That is, when the detected signal is too large (Drop In), when the average value of the detected signal is greater than or equal to the plurality of defect reference values, the defect is detected and stored in the temporary defect lists, and the offset is too large. When detected in an area eccentric by (Offset) (Thermal Aspect), the temporary defect lists are detected by detecting a case where the average values of the detected signals are offset by an offset larger than a plurality of defect reference values. Just save it to.

In the above, the preferred embodiments of the present invention have been described by way of example, but the scope of the present invention is not limited to the specific embodiments as described above, the present invention by those skilled in the art to which the present invention pertains Changes may be made as appropriate within the scope of the contents as set forth in the claims.

As described above, according to the present invention, by detecting defects with respect to a plurality of defect reference values, the defects of the disc can be detected more precisely than before without reducing the production efficiency. It can improve the reliability of hard disk drive.

Claims (13)

(a) performing a defect scan on the disk to be inspected to determine whether the defect is defective based on a plurality of different defect reference values; (b) generating a plurality of temporary defect lists corresponding to the plurality of defect reference values based on information of a sector detected as defect for each of the defect reference values; And and (c) selecting, from among the plurality of temporary defect lists, a temporary defect list that meets a predetermined criterion as a final defect list. The method of claim 1, The plurality of defect reference values, A defect detection method of a hard disk drive, characterized in that a Drop Out Defect Criteria for determining whether a signal detected during a defect scan is smaller than a predetermined reference. The method of claim 1, The plurality of defect reference values, A method of detecting a defect of a hard disk drive, comprising: an upper reference value, an intermediate reference value, and a lower reference value divided according to a degree of strictness recognized as a defect sector. The method of claim 3, wherein In step (c), Defect of the hard disk drive, characterized in that the temporary defect list of the plurality of temporary defect list, which is smaller than the predetermined threshold value and stored the information of the largest number of defect sectors as the final defect list Detection method. The method of claim 4, wherein The threshold is Defect detection method of a hard disk drive, characterized in that the reference value for poor processing of the disk when the number of defect sectors as a result of the defect detection of the disk is larger than the threshold. The method of claim 1, And a plurality of temporary defect lists are stored in a maintenance cylinder. The method of claim 1, And the final defect list is stored in a buffer memory. A recording medium having recorded a computer program for performing the method according to any one of claims 1 to 7. At least one disk; A magnetic head for recording a predetermined data on the disc and detecting a signal by reading the data; And Defect scan is performed on the disc to determine whether the defect is based on a plurality of different defect reference values, and the plurality of defects are determined based on information of a sector detected as defect for each of the defect reference values. And a controller for creating a plurality of temporary defect lists corresponding to the defect reference values, and selecting a temporary defect list suitable for a preset criterion from among the plurality of temporary defect lists as the final defect list. drive. The method of claim 9, The plurality of defect reference values, And a Drop Out Defect Criteria for determining whether a signal detected during a defect scan is smaller than a predetermined criterion. The method of claim 9, The plurality of defect reference values, A hard disk drive comprising an upper reference value, an intermediate reference value, and a lower reference value divided according to a degree of strictness recognized as a defect sector. The method of claim 11, The controller, And selecting a temporary defect list in which the information of the largest number of defect sectors is stored as a final defect list among the plurality of temporary defect lists, which is smaller than a preset limit value. The method of claim 12, The threshold is And a reference value for failing the disk when the number of defect sectors is greater than the threshold as a result of the defect detection of the disk.

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