JP2001343907A - Laser repair device and production method for display cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser repair device which can reduce tact time and can improve the manufacturing number of sheet per unit time. SOLUTION: The laser repair device is provided with a YAG laser device 2 which processes an object O disposed on a stage 11 by a laser beam, a microscope 4 with which processing work by the laser device 2 can be observed, and a detection function which detects a pixel showing abnormal display from the pixel of the object by image processing, and can perform detection for specifying a prescribed position and area. The designation of the position of detection in the detection function can be performed by a pixel block unit including at least two or more pixels, and the detection is performed for a detection objective area by a pixel block unit including at least two or more pixels.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser repair device for normalizing a pixel having a display pixel defect by operating a redundant circuit inside a glass substrate such as a liquid crystal display device or a PDP device.

[0002]

2. Description of the Related Art A laser repair device cuts and joins a re-circuit pattern by laser processing, and uses a liquid crystal display device, a PD.
By operating a redundant circuit inside a glass substrate such as a P device, a display panel having a display defect can be relieved.

[0003] Liquid crystal display devices have significant advantages of high image quality, thinness and light weight, and low power consumption, and are being marketed in notebook computers, portable devices, and the like, and are being improved in performance and manufacturing technology. Is desired.

In the liquid crystal display device, if the insulating property of the capacitor insulating film becomes insufficient due to foreign matter entering the auxiliary capacitor electrode during the manufacturing process, the voltage of the auxiliary capacitor power supply line is written to the pixel electrode. In addition, a display pixel defect occurs, and a problem that manufacturing yield is reduced occurs.

[0005] In order to remedy the problem of insulation failure of the auxiliary capacitance electrode, a laser beam such as a YAG laser is applied to the wiring between the auxiliary capacitance electrode and the pixel electrode to increase the resistance of the wiring. There is known a laser repair method of preventing writing of a voltage of an auxiliary capacitance power supply line and normalizing a display pixel defect.

[0006] Such a defect can usually be determined at the time of an array tester inspection and a cell process inspection. However, when a display pixel defect is found by the array tester, it is usually possible to obtain coordinate information, and the repair device side can use such an electronic device. If the information can be handled, it is possible to easily move to the target pixel.

However, if a defect is found during the inspection in the cell process, the repair device cannot obtain the coordinates of the display pixel defect. There is a problem that it takes time to detect the position of the target pixel for laser repair, and it is difficult to determine an abnormal image. In the inspection process of the cell process, the case where the laser repair device cannot acquire the coordinates of the display pixel defect generally means that a low-cost laser repair device is used, when product shipment is started or when a production line is started up, or when the process is started. This is when trouble occurs.

For example, when an inspection is performed on a display device that performs XGA display, usually, a cursor capable of displaying position coordinates is moved to obtain position coordinates by superimposing the cursor on an abnormal image. There are 3072 lines, and even if one line moves for 0.1 second, it takes 307 seconds in total, and the tact time of the inspection process is significantly reduced.

Further, as the display pixel pitch becomes narrower, it becomes more difficult to see abnormal pixels, and there is a problem that the work of superimposing the abnormal pixels on the cursor becomes more difficult.
This problem is particularly noticeable in a liquid crystal panel using a polysilicon TFT having a narrow pixel pitch and a large number of pixels.

A known laser repair device will be described with reference to FIG.

A laser beam 103 having a wavelength of 532 nm oscillated from a YAG laser device 102 having a laser source (not shown) passes through a microscope 104 of an infinite system, and
The light passes through the objective lens 104b having a magnification of 0 and is irradiated on the liquid crystal display device O to be subjected to laser repair.

In the laser repair processing, for example, when a short circuit occurs in the capacitance electrode of the pixel of the liquid crystal display device O, the laser beam 103 from the YAG laser device 102 is transmitted through the glass substrate of the liquid crystal display device O to the shorted capacitance electrode. By irradiating and processing the display pixel defect, a state in which the display pixel defect is driven only by the liquid crystal capacitance is realized and the bright spot defect is improved.

In general, the liquid crystal display O often has n defective pixel defects.
Is fixed to the stage 111 which is moved in the two X-Y directions by the control computer 121, and is sequentially moved for each pixel defect defect. The control computer 121 moves the stage 111 to arbitrary positions (coordinates) in the X-axis direction and the Y-axis direction by using a JOY stick (not shown) provided on a control panel (not shown).
Can be moved.

The stage 111 is covered with a stainless steel casing (not shown), and the casing is provided with a cover 113 for taking in and out a sample O such as a liquid crystal display device.

The microscope 104 is provided with a dichroic mirror (not shown) that transmits the laser beam 103 and reflects visible light in a predetermined direction.
For example, the short-circuit defective pixel A on the liquid crystal display device O is projected.

The image captured by the CCD 105 is transmitted to a monitor 106 via a video cable (not shown).
07 is displayed.

FIG. 6 (a) explains the inspection process of the liquid crystal cell, and shows a state where the state of the sample O set on the stage is captured by the CCD 105 and displayed on the monitor 106.

As shown in FIG. 6A, the liquid crystal display O
Is turned on entirely in an arbitrary color, and the horizontal cursor 152 and the vertical cursor 15 move one by one to the abnormal pixel 151.
3, the position coordinates 154 are obtained. The obtained position coordinates 154 are usually displayed on the liquid crystal display device O.

FIG. 6B illustrates the repair process of the abnormal pixel 151. The position coordinates 1 obtained in the inspection process are shown in FIG.
With 54, a defect location is performed.

Next, the main flow of the normal inspection process and the laser repair process will be described.

*** Inspection process *** A1) Set cell in inspection machine R A2) Cell alignment S A3) Cell lighting T A4) Change display pattern U A5) Find defect position coordinates W A6) Cell removal X ++ Laser repair process +++ 1) Place target cell on stage A 2) Turn on target cell B 3) Input defect position coordinates C 4) Auto alignment D 5) Auto focus E 6) 5 × objective lens field of view Automatic adjustment F 7) Search in 5x objective lens field of view G 8) Positioning H 9) Autofocus I 10) Automatic adjustment in 50x objective lens field of view J 11) Search in 50x objective lens field of view K 12) Position Take out L 13) Laser processing M 14) Replace objective lens N 15) Return to 4) O 16) Take out target cell from stage P 17) End

The character string in the above-mentioned flow indicates the work, and when a numerical value is substituted, the tact time is represented.

[0023]

In the conventional inspection process and laser repair process, when obtaining detailed defect coordinates, the tact is reduced for the above-described reason, and when the pitch becomes narrow, an abnormal pixel is difficult to see. There is a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and a defect position is designated by a pixel block having a number of pixels as a basic unit. To provide a laser repair device having a defect detection function in a range specified by (1).

[0025]

SUMMARY OF THE INVENTION The present invention has been made based on the above problems, and comprises a laser device for oscillating a laser beam, a stage arranged perpendicular to the laser beam and movable in a plane direction, A converging optical system that processes an object placed on the stage with the laser beam, an observation system that can observe the laser processing operation by the converging optical system, the object has pixels in a matrix, In a laser repair device having a detection function of detecting a pixel indicating an abnormal display from the pixel by image processing and specifying a predetermined position and a range, at least two pixels are specified in the detection position in the detection function. A laser which can be specified in units of pixel blocks including the above and is performed in units of pixel blocks whose detection target range includes at least two pixels. A pair devices.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic diagram illustrating a laser repair apparatus to which an embodiment of the present invention is applied.

As shown in FIG. 1, a laser repair device 1
A YAG laser beam 3 oscillated from a YAG laser device 2 having a YAG laser source (not shown), and a liquid crystal display device O for laser repair fixed on a stage
And a fisheye microscope 4 for irradiating a predetermined position.
The microscope 4 is provided with an epi-illumination system (not shown), and the position where the illumination light is applied to the sample O and the position of the marking can be confirmed through the window 14. In addition,
The microscope 4 can provide two-stage magnification, for example, 20 times and 50 times by switching or exchanging.

The microscope 4 also has a YAG laser beam 3
And a dichroic mirror (not shown) that reflects visible light, which is reflected light from a sample (liquid crystal display device) O illuminated by light from a lighting device (not shown), in a predetermined direction.

The stage 11 has two X-axis directions orthogonal to the YAG laser beam 3 and two orthogonal directions to the Y-axis direction.
It is movable in the axial direction, for example, at a pitch of 0.5 μm,
The movement is controlled by the control computer 21. A JOY stick (not shown) is used to input a movement instruction to the control computer 21, that is, movement information. At this time, the JOY stick indicates the current position of the stage 11 to the control computer with reference to a predetermined origin of the stage 11 as a reference.

The control computer 21 can move the stage 11 to arbitrary coordinates on a coordinate file in a memory (not shown) in response to an input from an operation panel (not shown) or a JOY stick (not shown). have. In the laser repair device 1 described above, under the control of the control computer 21, the display pixel defect occurring in the sample (liquid crystal display device) O, that is, the position of the pixel displaying the abnormal display is set to a plurality of pixels as a basic unit. It can be specified by a pixel block, and a defect at the position and range specified by the block can be detected.

The stage 11 is made of, for example, stainless steel.
It is covered by a housing 12 located between the microscope 4 and the stage 11.

A cover 13 for covering a sample O such as a liquid crystal display device fixed to the stage 11 is disposed on the housing 12.

The cover 13 is provided with a window 14 for observing the surface of the liquid crystal display device O fixed to the stage 11, and is provided on a sample O illuminated by a lighting device (not shown) provided in the housing 12. Pre-drawn markings can be checked.

The window 14 is, for example, a 5 mm-thick vinyl chloride plate. The window 14 has a light intensity of 532 nm, which is the wavelength of the YAG laser beam 3 oscillated from the YAG laser device 2.
An unillustrated film (filter) capable of attenuating to an intensity of / 20 or less is provided integrally. Thus, when the YAG laser beam 3 applied to the liquid crystal display device O in the housing 12 is reflected by the liquid crystal display device O, it is prevented from leaking outside through the housing 12 and the window 14. Therefore, even in the operating state in which the sample O in the housing is irradiated with the YAG laser beam 3, the worker (observer) can be protected at the class 1 level.

At the position where the visible light reflected by the dichroic mirror reaches, the reflected light from the sample O mounted on the stage 11 in the housing 12 is received, and the image corresponding to the sample O is received. Is provided. Therefore, for example, when a short-circuit defective pixel A exists on the liquid crystal display device O, the image A
Is enlarged at a predetermined magnification through the microscope 4 and guided to the CCD sensor 5 to be converted into an image signal.

This image signal is supplied to the monitor 6 via a video cable (not shown), and is displayed as a video 7.
Note that the display section of the monitor 6 is provided with a marker 6a that substantially indicates the center of the image area when the microscope 4 captures an image of an arbitrary position of the sample O. The stage precision is 0.5 μm, and the pixel pitch is 200 μm × 2.
By displaying the 00 μm pixels on a monitor with a 640 × 400 dot pitch, it is possible to realize the alignment of the marker 6a and the marking position of the sample O with a detailed accuracy of 1 μm.

At this time, the image captured by the CCD 5 is displayed, for example, as shown in FIG. 2A by turning on the entire surface of the liquid crystal display device O in an arbitrary color. By aligning the horizontal pixel block cursor 52 including the pixels for the frame with the vertical pixel block cursor 53 including the pixels for the m frames, the coordinates of the pixel block can be obtained. The obtained coordinates 54 of the pixel block are usually displayed on the liquid crystal display device O.

Next, a description will be given of a laser repair for a display pixel defect of a liquid crystal display device using the laser repair device shown in FIG. The laser repair device shown in FIG.
It is used in a process of repairing the detected image after the detection of the defect image.

FIG. 2B is a schematic diagram for explaining a defective pixel search step in the repair step, in which a defective pixel is searched from a pixel block composed of m × n pixels. This search is
The display gradation data of the target pixel block is digitized, captured as a pixel on the monitor 6, and subjected to image processing for difference from the image data of the normal pixel block to specify a defective pixel, but is not limited thereto. Not something.

FIG. 3 is a flowchart for explaining the main flow of the inspection process and the laser repair process using the laser repair device of the present invention shown in FIG.

<<<< Inspection Step >>>> A1) Set the cell in the inspection machine R A2) Cell alignment S A3) Cell lighting T A4) Change display pattern U A5) Obtain pixel block coordinates Y A6) Cell take-out X (((laser repair process))) 1) Place target cell on stage A 2) Turn on cell B 3) Input pixel block coordinate of defective pixel of target cell C 4) Auto alignment D 5) Auto focus E 6 ) Automatic adjustment in the field of view of the 5 × objective lens F 7) Search in the field of view of the 5 × objective lens Z 8) Positioning H 9) Autofocus I 10) Automatic adjustment in the field of view of the 50 × objective lens J 11) 50 × objective lens Search in the field of view K 12) Positioning L 13) Laser processing M 14) Objective lens replacement N 15) Return to 6) O 16) Remove the target substrate from the stage P 17) is the end.

Assuming that the character example in FIG. 3 is the tact time, if the difference in the tact between the conventional manufacturing method described above and the manufacturing method of the present invention described above is formed, the difference in the tact becomes (W −Y) + (G−Z).

As described above, in the laser repair apparatus of the present invention, the step of obtaining the position of a defective pixel is performed in units of pixel blocks in units of an arbitrary number of pixels.
Compared with the conventional process, the tact time of the inspection process is reduced. Further, it is only necessary to find a search tact of the laser repair process, which is deteriorated by a wide range in which the defect is detected in the laser repair process.

As shown in FIG. 4, the inventors changed the size of the pixel block and measured the working time of the pixel block coordinate acquisition tact including the defective pixel in the cell inspection process and the defect in the repair process. The image processing time of pixel detection was derived by calculation and actual measurement, and the total tact was derived. That is,
FIG. 4 shows the total tact “C” by summing each of the inspection tact “A” and the search tact “B” of the cell with respect to the number of the pixels in the pixel block, and the total tact “C”.
By determining the size of the pixel block so as to minimize the size, it is possible to know the size of the pixel block that maximizes the work efficiency.

In FIG. 4, the conventional example is when the number of pixels in the pixel block = 1, that is, the position on the Y axis. As is clear from FIG. 4, since the inspection tact decreases and the search tact increases as the number of pixels in the pixel block increases, the total value is better when the number of pixels in the pixel block is two or more. Is shown.

From these results, in the inspection step, the defect position is located in units of pixel blocks composed of at least two or more pixels, and this range is searched in the defect detection step in the laser repair step to obtain the coordinates of the defect position. It is recognized that the tact time can be reduced as compared with the tact time in the inspection process.

Further, in the inspection step, the defect position is located in units of blocks, and in the defect detection step in the repair step, all the search within this range is performed, so that a defective pixel that was overlooked during the inspection may be found. It becomes possible.

When a plurality of defective pixels are matched in one pixel block, the input of the pixel block coordinates only needs to be performed once, so that the input time can be reduced as compared with the conventional case.

Further, since the image processing performs detailed positioning, it has been confirmed that even if the pixel pitch becomes narrower, it can be detected without any problem.

In the above-described embodiment, the case where the detection mechanism of the pixel block including the defective pixel in the cell inspection is provided separately from the repair device is described. However, the present invention is not limited to this. It may be configured in a typical manner.

[0052]

As described above, according to the present invention, in the conventional inspection process and laser repair process, the problem that tact and abnormal pixels which are reduced by acquiring detailed defect coordinates are difficult to see is solved. Therefore, it is possible to shorten the processing tact time per sheet,
The number of sheets manufactured per unit time can be doubled.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an example of a laser repair device with an abnormal display pixel detection mechanism according to an embodiment of the present invention.

FIGS. 2A and 2B show an example of a display of a defective pixel in a cell inspection step and a repair step of the present invention, wherein FIG. 2A shows an example of a display in which a defect is detected, and FIG. The schematic diagram which shows the example of a display of time.

FIG. 3 is a flowchart illustrating each of a cell inspection process and a repair process according to the present invention.

FIG. 4 is a schematic diagram for explaining the relationship between the size of a pixel block and the operation time of searching for a cell inspection and a repair process.

FIG. 5 is a schematic diagram illustrating a known laser repair device.

6A and 6B are examples of display of defective pixels in a well-known cell inspection process and a repair process, in which FIG. 6A shows an example of a display in which a defect is detected, and FIG. The schematic diagram which shows the example of a display of.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Laser repair apparatus, 2 ... YAG laser apparatus, 3 ... YAG laser beam, 4 ... Microscope, 4a ... First magnifying lens (20 times), 4b ... Second 5 ... CCD sensor, 6 ... Monitor, 6a ... Marker, 11 ... Stage, 12 ... Housing, 13 ... Cover, 14 ... Window, 21 ... control computer.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // B23K 101: 36 B23K 101: 36 F term (Reference) 2H088 FA12 FA15 FA16 FA17 FA30 MA16 2H092 JB71 JB77 MA47 MA52 MA57 NA25 NA27 NA29 PA06 4E068 CA09 CA17 CA18 CC02 DA09 5G435 AA17 BB06 BB12 EE33 HH12 KK05 KK10

Claims (5)

[Claims] 1. A laser device for oscillating a laser beam, a stage arranged perpendicular to the laser beam and movable in a plane direction, and a focusing optics for processing an object arranged on the stage by the laser beam. System, an observation system that can observe the laser processing operation by the converging optical system,
A laser repair device having a detection function in which the object has pixels in a matrix shape, a pixel indicating an abnormal display is detected from the pixels by image processing, and a detection function capable of specifying a predetermined position and range is provided; A laser repair apparatus characterized in that the detection position in the function can be specified in pixel block units including at least two pixels, and the detection target range is specified in pixel block units including at least two pixels. 2. The converging optical system receives data relating to the position and range of a pixel indicating the abnormal display from the detecting function, and sends a laser beam to the pixel indicating the abnormal display detected in block units by the detecting function. The laser repair device according to claim 1, wherein the laser repair device can irradiate the laser beam. 3. The laser repair device according to claim 1, wherein the detection function is formed integrally with or independent of the laser repair device. 4. A method for manufacturing a display cell in which a light modulation layer is held between two substrates, comprising: detecting a defect position coordinate and a range in a pixel block unit including a plurality of pixels including a defective pixel of the display cell. A method for manufacturing a display cell, comprising: a step of searching for a defective pixel in the pixel block based on the position coordinates and the range of the pixel block. 5. The method according to claim 4, further comprising the step of repairing said defective pixel.