KR100699884B1 - Method for adaptive processing defects and apparatus thereof - Google Patents

Abstract

An adaptive defect processing method and a device thereof are provided to perform a defect scanning process for all sections of a disk irrespective of whether an error is generated, and to apply different defect references to the sections of the disk having different degrees of importance, thereby obtaining reliability on defect processing. Defects are scanned for all sections of a disk surface, to generate defect information(500). Detailed defect information which includes defect positions is generated by using the generated defect information(520). It is determined whether to process the defects by applying different defect references to each section of the disk surface according to reliability requested by the detailed defect information(530).

Description

Method for adaptive processing defects and apparatus thereof

1 is a flowchart illustrating a manufacturing process of a hard disk drive.

2 is a graph showing an example of a conventional defect processing method.

3 is a block diagram of a hard disk drive to which the present invention is applied.

4 is a block diagram of an adaptive defect processing apparatus according to the present invention.

5 is a flowchart of an adaptive defect processing method according to the present invention.

6A is a detailed flowchart illustrating an embodiment of process 530 of FIG. 5.

6B is a detailed flowchart of another embodiment of step 530 of FIG. 5.

7 is a graph showing a section with many defects as a result of scanning a disk surface according to the present invention.

8 is a graph showing a section in which a softness error or an error recoverable to ECC has occurred as a result of scanning a disk surface according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard disk drive, and more particularly, to a method and apparatus for adaptive defect processing in a surface defect scanning process during a manufacturing process of a hard disk drive.

1 is a flowchart illustrating a manufacturing process of a hard disk drive.

Referring to each step with reference to Figure 1, first step 100 of the manufacturing process is a process of assembling a head disk assembly (HDA), which is a mechanical part of a hard disk drive (HDD) in a clean room (clean room) Is done. The second step 110 of the manufacturing process is a process of recording a servo pattern for servo control of a magnetic head that reads and writes to a disk, which is a data recording medium, on a disk. The third step 120 of the manufacturing process is performed after combining the HDA made in the HDA assembly process 100 and the PCBA made in the printed circuited board assembly (PCBA) assembly process (usually performed after the HDA assembly process). As a test, we test that the HDA and PCBA work properly. The fourth step 130 of the manufacturing process is a burn-in test process which takes the longest time (normally 8 hours to 16 hours) of the HDD manufacturing process, and requires high temperature and high humidity without a separate test system. It is placed on a rack in the burn-in room of and then performed according to its own program (firmware). This burn-in test process refers to a process of finding a defect portion existing on a disk in advance so that a consumer can use the HDD normally and preempting the defect portion when the actual drive is used. The fifth step 140 of the manufacturing process is a process for checking whether the HDD set passed in the burn-in test process is normally defected and tests the defect processing state for each HDD set using a specific test system. do. The sixth step 150 of the manufacturing process ships one finished product through a process of shipment inspection, packaging and shipment.

During this burn-in test process, servo defects and data defects are inspected to reassign the defects so that they cannot be used after this process. Go through a series of related tests.

However, the conventional defect processing method applies the same defect criteria to sections on discs of different importance. If such a defect standard is high, the error of the level recoverable by ECC will be treated as a defect, and the softness error cannot be reduced. In addition, if such a defect standard is low, the defect may not be properly detected for a section on the disk where high reliability is required.

2 is a graph showing an example of a conventional defect processing method.

2 is a graph showing a surface defect scan step during a burn-in process, and a result of scanning a high frequency (corresponding to 2T) pattern recorded during a gap filling step before the surface defect scan process. Shows.

In the graph, the green axis represents the sector number and the vertical axis represents the magnitude of the signal. In this case, 200 denotes a case where a signal is detected without interruption and there is no defect. By the way, the conventional defect processing method does not scan the section after that once a defect is detected. 210 shows that an error occurs in the lead gate, thus no longer scanning the disk surface.

Therefore, in the conventional defect processing method, scanning intervals are different depending on whether an error occurs, and the same defect criteria are applied to intervals on disks having different importance, so that softness errors cannot be reduced and reliability cannot be secured. There is a problem that can not be defect efficiently for different intervals.

SUMMARY OF THE INVENTION The present invention provides an adaptive defect processing method which performs a defect scan on all sections of a disk regardless of whether an error occurs and applies different defect criteria to sections on disks having different importance. There is.

Another object of the present invention is to provide an adaptive defect processing apparatus to which the adaptive defect processing method is applied.

In order to solve the above technical problem, the present invention comprises the step of generating the defect information by scanning the defects for all sections of the disk surface, generating the detailed defect information including the position of the defect using the generated defect information And determining whether to defect the process by applying different defect criteria for each section of the disk surface according to the reliability required by the detailed defect information.

In order to solve the above other technical problem, the present invention provides a channel unit for generating the defect information using the result of scanning the defect for all the sections of the disk surface, the position of the defect using the defect information generated by the channel unit. Defect processing is performed by applying different defect criteria for each section of the disk surface according to a reliability required by the host unit for generating the detailed defect information including the detailed defect information and outputting the detailed defect information output by the host unit. It includes a code unit for determining.

Hereinafter, with reference to the drawings will be described a preferred embodiment of the present invention.

3 is a block diagram of a hard disk drive to which the present invention is applied.

The disks 310 are rotated by the spindle motor 334. Each of the heads 312 is located on the corresponding one of the disks 310, and the disks (from the E-block assembly 314 coupled with the rotary voice coil actuator 330). Corresponding to the support arms extending toward 310, respectively. In a read operation, the preamplifier 316 amplifies the signal picked up by either of the heads 312 and applies an analog read signal to the read / write channel circuit 318. In the write operation, the preamplifier 316 causes the coded write data applied from the read / write channel circuit 318 to be written onto the disc through the corresponding one of the heads 312. The read / write channel circuit 318 writes to or reads data from the disk through the preamplifier 316 and transmits the data to the host computer. The DDC 320 also interfaces the communication between the host computer and the microcontroller 324. The buffer RAM 322 temporarily stores data transmitted between the host computer and the microcontroller 324 and the read / write channel circuit 318. The microcontroller 324 controls track searching and track following in response to a read or write command received from the host computer. The memory 326 stores the execution program of the microcontroller 324 and various setting values. The servo driver 328 generates a driving current for driving the actuator 330 in response to a signal for position control of the heads 312 provided by the microcontroller 324 and applies it to the voice coil of the actuator 330. do. The actuator 330 moves the heads 312 on the disks 10 in response to the direction and level of the driving current applied from the servo driver 328. The spindle motor driver 332 rotates the disks 310 by driving the spindle motor 334 according to a control value for rotation control of the disks 310 generated from the microcontroller 324.

4 is a block diagram of an adaptive defect processing apparatus according to the present invention.

The disk 400 has recorded a predetermined test pattern for surface defect scan. This pattern can use a high frequency 2T pattern.

The recording / reading unit 410 reads a predetermined test pattern from the disc 400 and transmits the read result to the channel unit 420. In addition, when the record / reading unit 410 determines that the defect is to be processed by the code unit 410, the recording / reading unit 410 performs a predetermined recording operation at the corresponding position on the disc where the defect has occurred, thereby making the position inaccessible. In this case, preferably, the recording / reading unit 410 does not make the corresponding location inaccessible, but allows the location to be assigned to another location on the disc.

The channel unit 420 generates the defect information using the result of reading the test pattern received from the recording / reading unit 410. Defect information is information including the size, shape of the signal waveform, and the number of sectors accordingly as shown in FIG. 1.

The host unit 430 generates detailed defect information by using the defect information generated by the channel unit 420. At this time, the detailed defect information includes information regarding the position where the defect has occurred. Preferably, the detailed defect information includes information on the number of defects and the density of defects at the position where the defect is generated. When the detailed defect information is generated, the host unit 430 outputs it and transmits it to the code unit 440.

The code unit 440 determines whether or not to perform the defect processing by applying different defect criteria according to the detailed defect information output by the host unit 430. Preferably, the code unit 440 applies a high level of predetermined defect reference to the corresponding defect location when the defect location output by the host unit 430 corresponds to a data address section requiring high reliability. If the Defect position output by the host unit 430 corresponds to the data section, it is determined whether the Defect process is performed according to the Defect number and the Defect density for the Defect position. At this time, a section requiring high reliability is illustrated as a data address, but according to the needs of those skilled in the art, another sector section on the disk may be defined as a section requiring high reliability.

Preferably, a high level of predetermined defect standard may be defined as a criterion for determining that the defect is processed even if only one defect is detected at the corresponding defect location.

Preferably, the operation of determining whether or not the defect process is performed according to the number of defects and the density of the defects does not simply determine that the defects are to be processed only by detecting the defects once, but when the number of defects is high and the defect density is above a certain standard. This may be an operation of determining that only the corresponding defect is to be processed.

If the code unit 440 determines to process the corresponding defect, the recording / reading unit 410 is controlled to perform the defect processing operation at the corresponding defect position. As described above, the defect processing operation may be an operation of making the corresponding defect location inaccessible or allowing the corresponding defect location to be allocated to another location on the disk.

Preferably, the write / reader 410 of FIG. 4 may be implemented by the preamplifier 316 and the read / write channel circuit 318 of FIG. 3.

Preferably, the host unit 430 and the code unit 440 of FIG. 4 may be implemented by the microcontroller 324 of FIG. 3. In this case, the microcontroller 324 should have built-in firmware for the adaptive defect processing according to the present invention. Also, preferably, the host unit 430 and the code unit 440 of FIG. 4 may be implemented by the microcontroller 324, the DDC 320, and the host computer of FIG. 3. In this case, the host computer may perform an operation of generating the detailed defect information as described above.

5 is a flowchart of an adaptive defect processing method according to the present invention.

First, the defect is scanned for all sections on the disk to generate the defect information (step 500).

Next, the detailed defect information is generated using the generated defect information (S520). At this time, the detailed defect information includes information regarding the position where the defect has occurred. Preferably, the detailed defect information includes information on the number of defects and the density of defects at the position where the defect is generated.

Finally, different defect criteria are applied according to the detailed defect information to determine whether or not the defect process is to be performed (step 530).

6A is a detailed flowchart illustrating an embodiment of process 530 of FIG. 5.

First, it is determined whether the defect position corresponds to a section requiring high reliability (step 631). In this case, if the defect location does not correspond to a section requiring high reliability, a low level defect criterion is applied (step 633). The low-defect standard is a more relaxed criterion than the above-described high-defect predetermined defect standard, and is a criterion for deciding not to process the defect for the defect that is recoverable by ECC.

In this case, if the defect location corresponds to a section requiring high reliability, a predetermined level of defect is applied at a high level (step 632). Preferably, a high level of predetermined defect standard may be defined as a criterion for determining that the defect is processed even if only one defect is detected at the corresponding defect location.

Finally, it is determined whether or not the defect process is applied by applying an appropriate defect criterion according to the defect position as described above, and accordingly the defect process is performed on the disc (step 634). As described above, the defect processing operation may be an operation of making the corresponding defect location inaccessible or allowing the corresponding defect location to be allocated to another location on the disk.

6B is a detailed flowchart of another embodiment of step 530 of FIG. 5.

First, it is determined whether the defect position corresponds to a data section (step 635). In this case, if the defect location does not correspond to the data section, it is determined whether or not the defect is to be processed according to the reliability required by the defect location (step 637). At this time, the reliability required by the location of the defect is required by the skilled person, such as a section in which only one defect is not allowed, a section in which a small number of defects are allowed, and a section in which a large number of defects or dense defects are not allowed. You can decide by creating a table.

In this case, if the defect position corresponds to the data section, it is determined whether or not the defect process is performed according to the number of defects and the density of the defects at the corresponding defect position (step 636). Preferably, the operation of determining whether or not the defect process is performed according to the number of defects and the density of the defects does not simply determine that the defects are to be processed only by detecting the defects once, but when the number of defects is high and the defect density is above a certain standard. This may be an operation of determining that only the corresponding defect is to be processed.

Finally, the defect is processed according to the decision of whether or not to process the defect as described above (step 638). If it is determined in the above process that the defects are not processed, the defects at the corresponding defect positions correspond to the defects that can be recovered by soft defects or ECC. Such a defect is a level of defect that can be recovered even without a separate defect process. On the contrary, if it is determined that the corresponding defect is to be processed, the defect processing operation is performed on the disk (step 638). As described above, the defect processing operation may be an operation of making the corresponding defect location inaccessible or allowing the corresponding defect location to be allocated to another location on the disk.

7 is a graph showing a section with many defects as a result of scanning a disk surface according to the present invention.

In the graph, the green axis represents the sector number, and the vertical axis represents the magnitude of the signal.

The section 700 in which the amplitude is largely changed is a section in which the test pattern is not normally recorded or read normally, and a defect is generated. In the graph, since the amplitude has changed greatly many times, this section 700 corresponds to a section having many defects. At this time, according to the present invention, by referring to the sector number, track number, etc. of the corresponding defect position, it is determined whether the section is a section requiring high reliability or a data section, and an appropriate defect process is performed.

8 is a graph showing a section in which a softness error or an error recoverable to ECC has occurred as a result of scanning a disk surface according to the present invention.

In the graph, the green axis represents the sector number and the vertical axis represents the magnitude of the signal.

The period 800 in which the amplitude is largely changed is a section in which the test pattern is not normally recorded or read normally, and a defect has occurred. In the graph, since the amplitude changes only once, this section 800 is a section in which a soft error or an error recoverable by ECC has occurred. Therefore, no need for a separate defect process. However, according to the needs of those skilled in the art, if this section is a section requiring extremely high reliability, it is possible to perform a separate defect process for this section.

Preferably, a program for executing the adaptive defect processing method of the present invention on a computer can be recorded on a computer-readable recording medium.

The invention can be implemented via software. When implemented in software, the constituent means of the present invention are code segments that perform the necessary work. The program or code segments may be stored on a processor readable medium or transmitted by a computer data signal coupled with a carrier on a transmission medium or network.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary and will be understood by those of ordinary skill in the art that various modifications and variations can be made therefrom. However, such modifications should be considered to be within the technical protection scope of the present invention. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, according to the present invention, a defect scan is performed on all sections of a disc regardless of whether or not an error occurs, and different defect criteria are applied to sections on discs having different levels of importance, thereby determining whether to process a defect. It is possible to reduce errors that can be recovered by ECC or softness errors, to ensure the reliability of the defect processing, and to perform the defect processing efficiently.

Claims (5)

Generating defect information by scanning the defect for all sections of the disk surface; Generating detailed defect information including a defect location using the generated defect information; And And determining whether or not to perform the defect processing by applying different defect criteria for each section of the disk surface according to the reliability required by the detailed defect information. The method of claim 1, Determining whether or not the defect process is And if the defect location corresponds to a data address section requiring high reliability, determining whether to process the defect by applying a predetermined high level of defect standard to the defect location. The method of claim 1, Generating the detailed defect information Using the defect information to generate detailed defect information including a defect position, a defect number, and a defect density. Determining whether or not the defect process is And determining whether or not a defect process is to be performed according to the number of defects and the density of defects with respect to the defect position, when the defect position corresponds to a data section. A channel unit generating the defect information by using the result of scanning the defect for all sections of the disk surface; A host unit generating detailed defect information including a defect location using the defect information generated by the channel unit and outputting the detailed defect information; And And a code unit configured to determine whether or not to perform the defect processing by applying different defect criteria for each section of the disk surface according to the reliability required by the detailed defect information output by the host unit. The method of claim 4, wherein The detailed defect information further includes a defect number, a defect density, The code section If the defect location output by the host unit corresponds to a data address section requiring high reliability, it is determined whether or not the defect processing is applied by applying a predetermined high level of defect standard to the defect location, and outputted by the host unit. And if the defect location corresponds to a data section, it is determined whether or not the defect is to be processed according to the number of defects and the density of defects with respect to the defect location.

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