JP3056823B2 - Defect inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defect inspection apparatus,
For example, the present invention relates to a defect inspection device that inspects a liquid crystal display panel for defects.

[0002]

2. Description of the Related Art Recently, liquid crystal display panels have been widely used in various electronic devices. Moreover, the amount of information displayed on the liquid crystal display panel is increasing, and a liquid crystal display panel with a high display density is required. In order to increase the display density, it is necessary to make the wiring pattern between the liquid crystal display and the terminal thinner, and to make the interval between adjacent patterns narrower.

However, when the pattern density is increased, adjacent patterns may be electrically connected to each other due to insufficient etching in the pattern etching step.

[0004]

In order to inspect the above-mentioned defects, a prober type inspection apparatus is used. The prober type inspection apparatus performs an inspection between lines of a pattern, but has a problem that it is not possible to specify a position between the lines where a defect exists.

Therefore, in order to detect a defective portion, CC
A method of detecting defects by image processing using a D camera,
Alternatively, a method of detecting a defect position by measuring resistance between patterns has been considered. However, in the image processing method using the CCD camera, it is necessary to always detect the defect position while performing focusing, and there is a drawback that the inspection time becomes long. In addition, the method of measuring the resistance between patterns can detect the defect position when there is only one defect between the patterns, but cannot detect the defect position when there are a plurality of defect points. There is.

[0006] Therefore, a primary object of the present invention, can reduce the inspection time of the defects, yet even more defective locations is to provide an inspection apparatus that can detect.

[0007]

The invention according to claim 1 is
A defect inspection apparatus for inspecting a defect of a pattern on a workpiece, a table for moving the workpiece in XY directions,
Light source means for irradiating laser light along the pattern of the workpiece; light receiving means for receiving light reflected from the workpiece;
It is provided in front of the optical means and has a normal pattern on the workpiece.
Shields reflected reflected light and reduces scattered light from defect patterns.
The mask to be incident on the light receiving means and the scattering from the defect pattern
Detect defect size based on detection of irregular light
Image processing means and rotate the mask according to the direction of the pattern
And the light source means irradiates laser light along the pattern
Drive the table in such a way
The defect position is slightly moved to the repair center in accordance with
And control means for controlling the operation .

[0008] The invention according to claim 2 is the invention according to claim 1 .
In addition to the configuration, the work piece
Chuck table for determination and detected defects
The workpiece is irradiated with a correction laser beam for removal.
Fixed in the X and Y directions with the correction light source
A Z-axis table capable of moving the main light source means in the Z-axis direction;
It is configured with.

[0009]

[0010]

[0011]

SUMMARY OF defect inspection apparatus according to the present invention, path of the workpiece
Laser light is emitted along the turn and reflected from the workpiece
Light is incident on the mask to block the reflected light reflected by the normal pattern and guide the scattered light from the defective pattern to the light receiving means.
Can easily detect child scattered light the size of the defect in response to being detect <br/> from defect pattern based on the light reception output
Can be.

[0012]

FIG. 1 is an external perspective view of an embodiment of the present invention. Referring to FIG. 1, on a base 2 of a housing 1,
An XY stage 3 that is movable in a plane direction, that is, in the X and Y directions is arranged. On the XY stage 3, a workpiece chuck base 5 for positioning a liquid crystal panel as a workpiece is provided. In order to inspect a workpiece placed on the XY stage 3, a Z-axis table 4 is provided which is prohibited from moving in the XY directions and is movable only in the Z direction (vertical direction). The Z-axis table 4 is provided with an electric revolver 8, a light source 9 for illuminating a microscope, a CCD camera 10, and a laser light source 11 for correcting defects. The electric revolver 8 switches lenses having different magnifications according to the driving force of a built-in motor. The microscope illumination light source 9 illuminates the workpiece. The CCD camera 10 captures an image of the surface of the workpiece through the lens of the electric revolver 8. The defect correction laser light source 11 irradiates a defect on the surface of the workpiece with a correction laser beam to remove the defect portion. Further, a laser light source 6 for defect inspection is arranged on one side of the chuck base 5 to be inspected, and a light receiving section 7 for defect inspection is arranged on the other side.
The defect inspection laser light source 6 irradiates the workpiece with laser light for inspecting a defect of the inspection object, and a defect inspection light receiving unit 7.
Receives the reflected light. The defect inspection laser light source 6 and the defect inspection light receiving unit are fixed to a Z-axis mounting base.

FIG. 2 is a schematic block diagram of one embodiment of the present invention. Next, an electrical configuration of an embodiment of the present invention will be described with reference to FIG. The CPU 21 performs overall control according to a program stored in a built-in memory. That is, the CPU 21 sets the XY stage 3 to X
A command signal for moving in the direction is given to the X pulse controller 23 via the I / O 22. The X-pulse controller 23 generates an X-pulse according to the command signal, and gives it to the X-motor driver 24. The X motor driver 24 rotates the X motor 25 by the number of times corresponding to the given number of pulses. For this purpose, a DC servomotor is used as the X motor 25. The X motor 25 moves the XY table 3 in the X direction. The rotation angle of the X motor 25 is detected by an X encoder 26, which generates a pulse signal in accordance with the rotation of the X motor 25 and
Give 7 The X counter 27 counts the pulse signal and supplies the count output to the CPU 21 via the X counter circuit 28 and the I / O 22.

Similarly, the CPU 21 controls the XY stage 3
To the Y pulse controller 30 via the I / O 29. The Y pulse controller 30 generates a Y pulse according to the command signal,
Give to Y motor driver 31. Y motor driver 31
Rotates the Y motor 32 by the number of times corresponding to the number of Y pulses. The Y motor 32 is provided to move the XY stage 3 in the Y direction. The rotation speed of the Y motor 32 is detected by a Y encoder 33, and a pulse signal corresponding to the rotation speed is supplied to a Y counter. Y counter 34 counts the pulse signal, and provides the count output to CPU 21 via Y counter circuit 35 and I / O 29. The CPU 21 determines the positions of the XY stage 3 in the X and Y directions based on the count outputs of the X counter circuit 28 and the Y counter circuit 35. The CCD camera 10 captures an image of the surface of the workpiece, and outputs the captured output to the image processing circuit 3.
Give to 6. The image processing circuit 36 performs image processing on the output of the CCD camera 10 and outputs a defective image to the CPU via the I / O 37.
Give to 21. The CPU 21 stores the defective image in the storage device 3
8 and display it on the monitor 41.

The optical sensor 70 is included in the light receiving section 7 for defect inspection shown in FIG. 1, and the laser light source 6 for defect inspection shown in FIG.
When the laser light is applied to the surface of the workpiece from, the scattered light is received. The light receiving output of the optical sensor 70 is supplied to a signal processing circuit 39, where the signal is processed, and a defect signal is output to an I / O circuit.
It is provided to the CPU 21 via 40.

FIGS. 3 and 4 are detailed views of the defect inspection optical system shown in FIG. 2, and FIG. 5 is a view showing scattered light when a normal pattern and a defect pattern are detected.

As shown in FIG. 3, a condenser lens 51 is provided in front of the defect inspection laser light source 6, and the laser light from the defect inspection laser light source 6 is condensed to form a glass substrate as a workpiece. 52 is irradiated. A parallel pattern 53 is formed on the glass substrate 52. The laser light reflected by the pattern 53 enters a mirror 54. Mirror 5
4 deflects the reflected light toward the optical sensor 70. A mask 55 and a condenser lens 56 are provided between the mirror 54 and the optical sensor 70. The mask 55 is rotatably provided to block the reflected light of the normal pattern from the pattern 53 and to pass only the scattered light from the defective pattern. The optical sensor 70 detects only the scattered light from the defect pattern.

As shown in FIG. 5A, the scattered light reflected by the normal pattern 53 has an oval shape.
As shown in (b), if there is a defect pattern that short-circuits between the patterns 53, the scattered light pattern has a protruding defect portion. The scattered light of the normal portion of the pattern 53 is blocked by the mask 55, and only the scattered light of the defective portion passes through the mask 55 and is received by the optical sensor 70. Since the mask 55 is rotatably provided,
As shown in FIG. 4, the reflected light from the normal pattern 53 can be shielded even when the pattern 53 is in the horizontal direction.

FIGS. 6 and 7 are flow charts for explaining the specific operation of the embodiment of the present invention.

Next, with reference to FIG. 6 and FIG. 7, a description will be given of a defect inspection of a workpiece and an operation of correcting the defect according to one embodiment of the present invention. First, the workpiece is fixed to the workpiece chuck base 5 on the XY stage 3 shown in FIG. The XY stage 3 is moved to move the workpiece to the defect inspection start position based on the inter-defect pattern position data from the preceding inspection apparatus by the prober. At this time, X is parallel to the pattern 53 on the glass substrate 52.
The Y stage 3 is moved. Then, as shown in FIG. 3 described above, the pattern 53 is irradiated with laser light from the defect inspection laser light source 6 on the pattern 53, and whether or not scattered light from the defect pattern is detected by the optical sensor 70. Is detected whether or not there is a defect. Pattern 53
XY stage 3 until pattern 53 is found
And move it in the parallel direction.

When the optical sensor 70 detects a defect in the pattern 53, the movement of the XY stage 3 is temporarily stopped. Then, an image of the defective portion is captured by the CCD camera 10, and an image processing inspection is performed. This image processing inspection is performed according to the flowchart shown in FIG. That is, the XY stage 3 is minutely moved in the direction parallel to the pattern 53, the image of the defective portion is captured by the CCD camera head 10, and focusing is performed. The image processing circuit 36 processes an image signal from the CCD camera 10 and
This is given to the CPU 21 via O37. The CPU 21 calculates the size of the defect and moves the XY stage 3 so as to move the defect position to the correction position. When the defective portion is extracted by the image processing in this manner, the image processing inspection ends, and the repairing shown in FIG. 6 is performed.
That is, the defect correction laser light source 11 shown in FIG. 1 irradiates the defect portion with laser light to remove an unnecessary pattern. When the correction is completed, the defect inspection is performed again to the inspection end position. During this time, if a defect is detected again, the above-described defect correction operation is performed each time. When the inspection and correction are completed, the XY stage 3 moves to the workpiece removal position, and the inspection object chuck base 5 The work piece is released from being fixed.

[0022]

As described above, according to the present invention, a laser beam is irradiated along a pattern of a workpiece, and
The size of the defect is inspected by guiding the reflected light to the mask, blocking the reflected light reflected by the normal pattern of the workpiece, and detecting the scattered light from the defect pattern. The defect inspection time can be reduced as compared with the image processing method using a CCD. Further, the problem that the defect position cannot be detected when a plurality of defective portions exist as in the conventional resistance measurement method can be solved.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an embodiment of the present invention.

FIG. 2 is a schematic block diagram of one embodiment of the present invention.

FIG. 3 is a detailed view of a defect inspection optical system shown in FIG. 2;

FIG. 4 is a view for explaining a method of inspecting a defect by rotating the mask shown in FIG. 3;

FIG. 5 is a diagram showing scattered light when a normal pattern and a defective pattern are detected.

FIG. 6 is a flowchart for explaining the operation of one embodiment of the present invention.

FIG. 7 is a specific flowchart of the image processing inspection shown in FIG. 6;

[Explanation of symbols]

 Reference Signs List 1 housing 2 base 3 XY stage 4 Z-axis table 5 chuck base for inspection object 6 laser light source for defect inspection 7 light receiving unit for defect inspection 8 electric revolver 9 light source for microscope illumination 10 CCD camera 11 laser light source for defect correction 21 CPU 22 , 29,37,40 I / O 23 X pulse controller 24 X motor driver 25 X motor 26 X encoder 27 X counter 28 X counter circuit 30 Y pulse controller 31 Y motor driver 32 Y motor 33 Y encoder 34 Y counter 35 Y counter Circuit 36 Image processing circuit 39 Signal processing circuit 51, 56 Condensing lens 52 Glass substrate 53 Pattern 54 Mirror 55 Mask 70 Optical sensor

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01N 21/956 G01B 11/24 G02F 1/13 101

Claims (2)

(57) [Claims] 1. A defect inspection apparatus for inspecting a defect of a pattern on a workpiece , a table for moving the workpiece in XY directions, and a light source for irradiating a laser beam along the pattern of the workpiece. hand stage, the light receiving means for receiving reflected light from the workpiece, is provided in front of said light receiving means, the normal path of the workpiece
Shields the reflected light from the turn, from the defect pattern
A mask that causes the scattered light to enter the light receiving unit, and the scattered light from the defect pattern is reduced by the light receiving unit.
Image that detects the size of the defect according to the detection
Processing means, and the mask according to the direction of the pattern.
The light source is rotated along the pattern.
The table is driven to irradiate laser light,
Repair defect position according to detection of defect pattern
A defect inspection apparatus including a control unit for minutely moving the ring to the center of the ring . 2. A further disposed on the table, corrected for irradiating the chuck table for positioning a workpiece, the modified laser beam for removing the defects detected by the image processing unit Light source means,
And said fixed relative to the XY directions, the modified light source means includes a Z-axis table movable in the Z-axis direction, a defect inspection apparatus according to claim 1.