KR20120031872A - Glass substrate defect inspection device and glass substrate defect inspection method - Google Patents

Abstract

PURPOSE: A glass substrate defect inspecting device and an inspection method thereof are provided to reduce or remove bouncing phenomenon and steadily perform an inspection by reducing the corrected amount during the inspection. CONSTITUTION: A glass substrate(100) comprises a lifting device, a transfer device, and an optical inspection device. The lifting device lifts up a glass substrate(P) using air. The transfer device transfers the glass substrate to an inspection area where the lifting device is absent. The optical inspection device takes a picture of the glass substrate, thereby performing an inspection. A glass substrate defect inspecting device comprises a reduction device. The reduction device reduces the displacement caused by the bouncing of an end part of the glass substrate toward a transferring direction.

Description

Glass substrate defect inspection apparatus and glass substrate defect inspection method {GLASS SUBSTRATE DEFECT INSPECTION DEVICE AND GLASS SUBSTRATE DEFECT INSPECTION METHOD}

This invention relates to a glass substrate defect inspection apparatus and a glass substrate defect inspection method, and relates to the glass substrate defect inspection apparatus and glass substrate defect inspection method which can be inspected with high precision.

Manufacture of a liquid crystal display panel and a solar cell panel is performed by forming a pattern on a glass substrate by photolithography technique etc. At that time, if defects such as scratches or foreign matter on the surface of the glass substrate exist, the pattern is not formed satisfactorily, which causes a defect. For this reason, the defect inspection of the surface of a glass substrate, a foreign material, etc. is conventionally performed using the defect inspection apparatus.

In order to perform defect inspection, it is necessary to convey a glass substrate to a defect inspection apparatus, and to test. Conventionally, robots, roller conveyors, and the like are used, but materials used for the adsorption pads of the robots and rollers of the roller conveyors are attached to the glass substrate at the time of conveyance or cause scratches and defects of foreign substances. For this reason, Patent Literature 1 discloses a configuration in which a glass substrate is conveyed in a non-contact manner, in which the end portion of the glass substrate is adsorbed and held, and the air is floated to convey the glass substrate. In addition, Patent Document 2 describes a method for inspecting scratches or foreign matter on a glass substrate.

Japanese Patent Application Publication No. 2006-188313 Japanese Patent Application Laid-open No. Hei 9-257642

In the method of conveying a glass substrate by the air floating mentioned above, the flatness of a conveyance direction is lost by generation | occurrence | production of the tip of a glass substrate by the inertia at the time of conveyance, etc. There is a problem. This problem becomes more remarkable with the thinning of the glass substrate of today.

Although the patent document 1 discloses conveying a glass substrate, stopping and processing, there is no recognition about the said subject at the time of the inspection during conveyance, and also there is no indication about the solution to a subject. Moreover, also about patent document 2, although the optical test | inspection apparatus is disclosed, there is no recognition about the said subject of inspecting during conveyance, and there is no indication about a solution.

This invention is made | formed in view of the said subject, and provides the glass substrate defect inspection apparatus or glass substrate defect inspection method which can ensure the flatness of the conveyance direction of a glass substrate, and can inspect with high precision.

The present invention has at least the following features in order to achieve the above object.

The present invention provides a glass substrate defect inspection apparatus or inspection method for generating a floating force by air and causing the floating of the glass substrate to be transported to the inspection area without the floating force, and imaging and inspecting the glass substrate in the inspection area. The first aspect of the present invention is to reduce the amount of displacement caused by jumping of an end portion of the glass substrate in the conveying direction in the inspection region, and to perform the inspection.

The present invention is also characterized in that the reduction measures the displacement amount of the glass substrate in the inspection area, and moves the imaging means for imaging based on the displacement amount measurement result.

The present invention is further characterized in that the speed pattern of the conveyance speed of the glass substrate in the inspection region is determined in advance, and the glass substrate is inspected based on the predetermined acceleration.

The present invention is also characterized by inspecting at least one of bubbles in the glass substrate and scratches present on the surface of the glass substrate.

The present invention is also characterized in that the displacement measuring means is a non-contact laser displacement meter.

Moreover, this invention is the 6th characteristic that the said test | inspection provided the imaging means to image the said imaging means to the lower part of the conveying apparatus which conveys the illumination means which illuminates the said glass substrate in the said conveyance means.

According to this invention, the glass substrate defect inspection apparatus or the glass substrate defect inspection method which can ensure the flatness of the conveyance direction of a glass substrate, and can inspect with high precision can be provided.

1 is a block diagram showing a first embodiment of a glass substrate defect inspection apparatus.
It is a figure which shows schematic structure which looked at the conveyance part of 1st Embodiment of the glass substrate defect inspection apparatus of this invention from the top.
3 is a diagram showing the configuration of the precision floating stage and the high injury stage.
4 shows measurement results of the amount of displacement of the tip of the glass substrate at the position from the end face of the precision stage.
It is a figure which shows the structure of the inspection part of 1st Embodiment of the glass substrate defect inspection apparatus of this invention.
FIG. 6 is a diagram showing a control method of a second embodiment of the present invention for securing flatness of a glass substrate in one glass substrate defect inspection apparatus. FIG.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of the glass substrate defect inspection apparatus of this invention is described based on drawing.

FIG. 1: is a block diagram which shows 1st Embodiment of the glass substrate defect inspection apparatus 100. As shown in FIG. The glass substrate defect inspection apparatus 100 is largely distinguished from the air floating stage by holding the inspection unit 10 for inspecting the glass substrate P and the air floating stage 20 and the glass substrate P while floating. 20) a conveying unit 40 having a drive unit 30 for conveying an image, a compressed air supply source 51 for supplying compressed air to the conveying unit 40, and a vacuum supply source 52 for inhaling air; The air supply intake part 50 and the whole control part 60 which monitors the state of each part, and controls each part are provided.

FIG. 2: is a figure which shows schematic structure which looked at the conveyance part 40 of 1st Embodiment of this invention from the top. The air floating stage 20 has a rectangular dividing stage 21 arranged in plural in the direction Y perpendicular to the conveyance X direction and the conveyance X direction. The dividing stage 21 has the precision floating stage 21S provided in both ends, and the high floating part stage 21H provided between them. R between the division stages 21 in the conveyance (X) direction is an inspection region for inspection described later.

The drive part 30 is provided to the linear guide 31 provided along the conveyance (X) direction of the air floating stage 20, the linear actuator 32 which runs along the linear guide 31, and the linear actuator 32. The gripper 33 is fixed and holds the glass substrate P, and the linear scale 34 which detects the position of the linear actuator 31 on the linear guide 31 (the conveyance (X) direction) is detected.

The overall control part 60 shown in FIG. 1 reads the positional information of the linear scale 34, and controls the conveyance speed and the gripper 33. As shown in FIG.

FIG. 3A shows the structure of the precision floating stage 21S, and FIG. 3B shows the structure of the high-lever stage 21H. As described above, the inspection is performed in the inspection region R having a width of about 40 mm between the adjacent dividing stages 21. Therefore, the precision floating stage 21 raises the glass substrate P so as to maintain the flatness of the glass substrate P with the inspection area R interposed therebetween. For this purpose, the precision floating stage 21S sucks air and a jet port PA (white circle) for blowing compressed air in order to float the glass substrate P, as shown in Fig. 3A. The suction port PV (black circle) which adsorb | sucks a glass substrate is alternately arrange | positioned. Then, the compressed air supply source 51 and the vacuum supply source 52 are controlled to balance both to obtain flatness of the glass substrate P. FIG. On the other hand, the high-lever part stage 21H has only the blowing port PA which blows out compressed air which raises the glass substrate P, as shown in FIG.3 (b), and stably sets the glass substrate P to it. It does not raise the load to lower the conveyance speed.

However, as shown in FIG. 4, the flatness of the glass substrate P falls by various factors.

FIG. 4: is a figure which shows the measurement result of the displacement amount (1 mm / 1 scale) of the tip Pt (refer FIG. 2) of the glass substrate P from the end surface of the precision stage 21S. Fig. 4A shows the measurement results of a glass substrate with an area of 880 mm × 680 mm and a thickness of 0.7 mm, and Fig. 4B shows the measurement results of a glass substrate with the same area and thickness of 0.4 mm. One division of the displacement amount of the vertical axis is 1 mm and is shown based on the measurement result at the position of the end surface of the precision stage 21S. In addition, as shown later, in order to show the measurement result in three positions, the position on a chart is shifted | shifted and the absolute value is meaningless. The measurement is performed by a non-contact laser displacement meter, and the measurement conditions are a conveyance speed of 250 mm / s and a sampling time of 1 ms on a glass substrate. The measurement position is the position Ia spaced 10 mm from the end Ps (see FIG. 2) of the glass substrate in the Y direction perpendicular to the conveying direction, and the positions Ib and Ic further spaced 310 mm and 610 mm from the position of the 10 mm. 3 places in total.

As can be seen from FIG. 4, the following three kinds are mentioned as general trends. First, the displacement amount is large in the central portion Ib, and relatively small at the ends Ia and Ic in the Y direction. Second, the change of the displacement amount is large at the position about 10 mm from the end face of the precision stage 21S in the center part Ib. Third, the thinner the thickness of the glass substrate, the larger the displacement amount. In the glass of thickness 0.4mm shown in FIG.4 (b), the largest displacement amount is 100 micrometers.

Thereafter, in the glass substrate defect inspection apparatus for inspecting bubbles and scratches described as an embodiment of the present invention, the allowable flatness needs to fall within the range of, for example, ± 50 µm.

FIG. 5: is a figure which shows the structure of the inspection part 10 of 1st Embodiment of the glass substrate defect inspection apparatus of this invention which can implement this. In this embodiment, the amount of jumping (displacement amount) of the glass substrate P at the inspection position is measured using a line sensor as the image pickup means to be inspected, and the image pickup means is always focused on the basis of the displacement amount. The following control is performed to follow the position of, so that the flatness is secured in the sense that the distance is kept constant from the inspection unit, although it is not actually flat.

The inspection unit 10 includes a scratch inspection unit 10A for inspecting scratches of the glass substrate P, and a bubble inspection unit 10B for inspecting bubbles.

The scratch inspection part 10A is divided into the imaging unit 11A and the light source unit 16A. The imaging unit 11A is fixed to the housing of the image sensor unit 11A and the line sensor 12A which detects scattered light through the light receiving lens 13A from the surface or the back surface of the glass substrate P, and the glass substrate P An imaging unit driver for raising and lowering the imaging unit including the line sensor 12A and the light receiving lens 13A based on the distance detection sensor 14A for measuring the displacement amount G with respect to the detection result of the distance detection sensor 14A. Has 15A. In this embodiment, a line CCD is used as the line sensor 12A for imaging a predetermined line-shaped range, and a non-contact laser displacement meter is used as the distance detection sensor 14A.

In addition, the imaging unit driver 15A includes the motor 15Aa fixed to the housing of the imaging unit 11A, the ball joint 15Ab rotated by the drive motor 15Aa, and the ball joint 15Ab. 15 A of support parts provided in both ends fixed to 11 A of housings, and the nut 15Ac fixed to the imaging part and moving up and down by rotation of the ball joint 15Ab are included.

On the other hand, the light source unit 16A includes a laser light source 17A, a mirror 18A for illuminating the laser light in all directions, and a condenser lens 19A in order to detect scratches on the order of 10 μm.

Due to these configurations, at least the tip portion Ptb (the constant range from the tip portion Pt shown in FIG. 2) of the glass substrate P comes to the displacement such as jumping (injury) when it comes to the inspection region R. By following the image pickup section, scratches can be detected reliably. Of course, not only the tip part Ptb but also the other part may detect the displacement amount similarly, and may control an imaging part. In particular, the flatness is also lost in the rear end portion Pbb of the glass substrate (a constant range from the rear end portion Pb of the glass shown in Fig. 2), and the effect is high.

On the other hand, the bubble inspection section 10B basically has the same configuration as the scratch inspection section 10A. The bubble inspection unit 10B detects bubbles by the luminance non-uniformity of the imaging result by the imaging means 12B. For that purpose, LED or fluorescent lamp which can irradiate extensively is used as the light source 17B. The other structure is the same, and the imaging means also uses the line CCD in order to image efficiently with the movement of the glass substrate P. FIG.

Therefore, also in the bubble inspection part 10B, a bubble can be detected reliably by following an imaging part to the displacement, such as a spring when the tip part Ptb of the glass substrate P came to the inspection area | region R. As shown in FIG.

In the above embodiment, the scratch inspection unit 10A and the bubble inspection unit 10B are provided in different inspection regions, but may be provided adjacent to the same inspection region.

In addition, although the inspection part 10 was provided in the above-mentioned embodiment in the direction perpendicular | vertical to the conveyance (X) direction, you may provide in several places. According to the measurement result of FIG. 4, since the loss of flatness is few in the edge part parallel to the conveyance direction of the glass substrate P, you may arrange | position many test | inspection parts 10 in the center part side with a large loss of flatness.

In the said embodiment, the case where the line was comprised with the some test | inspection apparatus or the processing apparatus was demonstrated to the example. Of course, the above embodiment is effective also in one inspection apparatus. It is a figure which shows the control method of 2nd Embodiment of this invention which ensures the flatness of a glass substrate in one glass defect inspection apparatus. In one glass defect inspection apparatus, after loading a glass substrate on a stage, it accelerates | examines and inspects and decelerates. This acceleration and deceleration destroys the flatness of the glass substrate P, in particular, the front end portion Ptb and the rear end portion Pbb. FIG. 6A illustrates that the front end Pt of the glass substrate P rapidly accelerates before entering the inspection region R (time Tt) and is imaged at a predetermined speed at a predetermined speed. The glass substrate P It shows the case where the rear end Pbb of) decelerates after passing the inspection area R (time Tb). 6B relaxes the acceleration deceleration time and accelerates until the tip Pt of the glass substrate P enters the inspection region R or passes through the inspection region R. The case where a predetermined speed is obtained and after which the rear end Pbb of the glass substrate P enters the test | inspection area | region R or after passing through the test | inspection area | region R is shown is the case where it test | inspects while decelerating. In the case of FIG. 6B, since the conveyance speed changes during the inspection, the position is detected by the linear scale 34 shown in FIG.

6 (c) and 6 (d) show the amount of springing up, that is, the displacement amount of the glass substrate P at the time of inspection for FIGS. 6 (a) and 6 (b), respectively. If the acceleration is large, the springing of the front end portion Ptb and the rear end portion Pbb of the glass substrate P increases. Although it depends also on the thickness of the glass substrate P, as can be seen from FIG.6 (c), FIG.6 (d), when acceleration is large generally, in the front-end | tip part, rear end part, especially front end part of glass substrate P, , The amount of springing up.

Therefore, the displacement amount (spread amount) is measured in advance with respect to the thickness in the glass substrate P, the speed pattern which falls into the displacement amount of an allowable range is calculated | required, and is used for actual inspection. If the displacement amount does not fall within the allowable range, it is performed in combination with the method shown in the first embodiment to reduce the correction amount at the time of inspection and to perform the inspection more stably.

As described above, according to the second embodiment described above, the popping phenomenon can be reduced or eliminated, so that the flatness of the glass substrate in the conveying direction can be ensured, and the glass substrate can be inspected with high accuracy.

In the embodiment described above, inspection at the front end or the rear end of the glass substrate is mainly described. Along with the thinning of the glass substrate, in some other areas, the substrate may also spring up (injury) or upset. In that case, the displacement may be measured over the entire area to control the flatness.

10: inspection unit
10A: scratch inspection unit
10B: Bubble Inspection Department
11A, 11B: Imaging Unit
12A, 12B: line sensor (imaging means)
13A, 13B: Light receiving lens
14A, 14B: distance detection sensor (non-contact laser displacement meter)
15A, 15B: Imaging unit driver
16A, 16B: Light Source Unit
17A: Laser Light Source
18A: Mirror
19A: Condensing Lens
20: air floating stage
21: split stage
21S: Precision Flotation Stage
21H: high-float stage
30: drive unit
31: linear guide
32: linear actuator
33: Gripper
34: linear scale
40: conveying unit
50: air supply intake
51: compressed air source
52: vacuum source
60: total control unit
100: glass substrate defect inspection device
P: glass substrate
PA: Blowing Air Outlet
PV: suction port of air
Pb: rear end of glass substrate
Pbb: rear end of glass substrate
Pt: tip of glass substrate
Ptb: tip of glass substrate
R: inspection area

Claims (10)

Glass substrate which has a floating apparatus which floats a glass substrate by air, the conveying apparatus which conveys the said glass substrate to the test | inspection area | region without the said floating apparatus, and the optical inspection apparatus which image-captures and inspects the said glass substrate in the said test | inspection area | region. In the defect inspection apparatus,
The glass substrate defect inspection apparatus characterized by including the reducing means which reduces the displacement amount by the spring of the edge part of the conveyance direction of the said glass substrate in the said inspection area | region. The said reducing means is a movement which moves the imaging means for imaging based on the displacement amount measuring means which measures the said displacement amount of the said glass substrate in the said inspection area | region, and the detection result of the said displacement amount measurement means. The glass substrate defect inspection apparatus characterized by having a means. The glass substrate defect inspection apparatus according to claim 2, wherein the displacement amount measuring means is a non-contact laser displacement meter. The glass pattern of Claim 1 or 2 WHEREIN: The speed pattern of the conveyance speed of the said glass substrate in the said inspection area | region is predetermined, and the said glass substrate is inspected based on the said predetermined speed pattern. Board defect inspection device. The glass substrate defect inspection according to any one of claims 1 to 3, wherein the optical inspection device inspects at least one of bubbles in the glass substrate and scratches present on the surface of the glass substrate. Device. The said optical inspection apparatus provided the illumination means which illuminates the said glass substrate in the lower part of the said conveyance apparatus, and the said imaging means in the upper part of the said conveyance means, The glass substrate defect inspection apparatus of Claim 5 characterized by the above-mentioned. . In the glass substrate defect inspection method, the glass substrate is generated by floating by air and floated, conveyed to the inspection region without the floating force, and the glass substrate is imaged and inspected in the inspection region.
A glass substrate defect inspection method, characterized in that the amount of displacement due to springing of an end portion in the conveyance direction of the glass substrate in the inspection region is reduced to perform the inspection. 8. The glass substrate defect inspection according to claim 7, wherein the reduction measures the displacement amount of the glass substrate in the inspection area and moves the imaging means for imaging based on the displacement amount measurement result. Way. The glass substrate defect according to claim 7 or 8, wherein an acceleration of a conveyance speed of the glass substrate in the inspection region is determined in advance, and the glass substrate is inspected based on the predetermined acceleration. method of inspection. The glass substrate defect inspection method according to claim 7 or 8, wherein at least one of bubbles in the glass substrate and scratches present on the surface of the glass substrate is inspected.

Images