JP2012073036A - Glass substrate defect checkup device and glass substrate defect checkup method - Google Patents

Abstract

【Task】
An object of the present invention is to provide a glass substrate defect inspection apparatus or a glass substrate defect inspection method capable of ensuring flatness in the conveyance direction of a glass substrate and inspecting with high accuracy.
[Solution]
The present invention relates to a glass substrate defect inspection apparatus or inspection method in which a glass substrate is levitated by generating a levitating force with air, transported to the inspection region without the levitating force, and imaging and inspecting the glass substrate in the inspection region. In the inspection area, the amount of displacement due to the jumping of the end portion of the substrate glass in the transport direction is reduced, and the inspection is performed. Further, the reduction is characterized in that the displacement amount of the glass substrate in the inspection region is measured, and the imaging means for imaging is moved based on the displacement amount measurement result.
[Selection] Figure 5

Description

  The present invention relates to a glass substrate defect inspection apparatus and a glass substrate defect inspection method, and more particularly to a glass substrate defect inspection apparatus and a glass substrate defect inspection method that can be inspected with high accuracy.

  Manufacture of a liquid crystal display panel and a solar cell panel is performed by forming a pattern on a glass substrate by a photolithography technique or the like. At that time, if there are defects such as scratches or foreign matter on the surface of the glass substrate, the pattern is not formed satisfactorily, causing a defect. For this reason, conventionally, a defect inspection apparatus has been used to inspect defects such as scratches and foreign matter on the surface of a glass substrate.

  In order to carry out the defect inspection, it is necessary to transport the glass substrate to a defect inspection apparatus for inspection. Conventionally, robots, roller conveyors, etc. are used, but the materials used for the robot's suction pad and rollers of the roller conveyor adhere to the glass substrate during transport, and cause damage and foreign matter defects. Become. For this purpose, Patent Document 1 discloses a configuration in which an end portion of a glass substrate is sucked and held and air-lifted to convey the glass substrate as a technique for conveying the glass substrate in a non-contact manner. Patent Document 2 describes a method for inspecting scratches or foreign matters on a glass substrate.

JP 2006-188313 A Japanese Patent Laid-Open No. 9-257642

  In the above-described method of transporting a glass substrate by air levitation, there is a problem that the flatness in the transport direction is lost due to the occurrence of jumping of the front end portion of the glass substrate due to inertia during transport, and inspection cannot be performed with high accuracy. This problem has become more prominent with the recent thinness of glass substrates.

  Patent Document 1 discloses that a glass substrate is transported, stopped, and processed, but there is no recognition of the above problems when inspecting during transport, and there is no disclosure of solutions to the problems. . Also, Patent Document 2 discloses an optical inspection device, but there is no recognition of the above-mentioned problem of inspection during conveyance, and there is no disclosure of a solution.

  This invention is made | formed in view of said subject, and it is providing 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 test | inspect accurately.

In order to achieve the above object, the present invention has at least the following features.
The present invention relates to a glass substrate defect inspection apparatus or inspection method in which a glass substrate is levitated by generating a levitating force with air, transported to the inspection region without the levitating force, and imaging and inspecting the glass substrate in the inspection region. The first feature is that the inspection is performed by reducing the amount of displacement due to the jumping of the end portion in the transport direction of the substrate glass in the inspection region.

According to a second aspect of the present invention, the reduction is to measure the amount of displacement of the glass substrate in the inspection region and to move the imaging means for imaging based on the displacement amount measurement result.
Furthermore, the present invention has a third feature that a 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.

Furthermore, the present invention is characterized in that at least one of bubbles in the glass substrate and scratches present on the surface of the glass substrate are inspected.
The fifth feature of the present invention is that the displacement measuring means is a non-contact type laser displacement meter.

  Furthermore, the present invention is characterized in that the inspection is characterized in that the illumination means for illuminating the glass substrate is provided at a lower part of the conveying device for conveying, and the imaging means for imaging is provided at the upper part of the conveying means. .

  ADVANTAGE OF THE INVENTION 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 test | inspect accurately can be provided.

It is a block diagram which shows 1st Embodiment of a glass substrate defect apparatus. It is the figure which showed schematic structure which looked at the conveyance part of 1st Embodiment of the glass substrate defect apparatus of this invention from the upper part. It is the figure which showed the structure of the precision levitation stage and the high floating part stage. It is the figure which showed the measurement result of the displacement amount of the front-end | tip of the glass substrate in the position from the end surface of a precision stage. It is a figure which shows the structure of the test | inspection part of 1st Embodiment of the glass substrate defect apparatus of this invention. It is a figure which shows the control method of the 2nd Embodiment of this invention which ensures the flatness of a glass substrate in one glass substrate test | inspection apparatus.

Hereinafter, an embodiment of a glass substrate defect apparatus of the present invention will be described based on the drawings.
FIG. 1 is a block diagram showing a first embodiment of a glass substrate defect apparatus 100. The glass substrate inspection apparatus 100 is broadly divided into an inspection unit 10 that inspects the glass substrate P, and a conveyance unit that includes an air levitation stage 20 and a drive unit 30 that conveys the air levitation stage 20 while holding and floating the glass substrate P. An air supply intake section 50 comprising a section 40, a compressed air supply source 51 that supplies compressed air to the transport section 40, and a vacuum supply source 52 that sucks air, and the whole that controls the state of each section And a control unit 60.

  FIG. 2 is a diagram illustrating a schematic configuration of the transport unit 40 according to the first embodiment of the present invention as viewed from above. The air levitation stage 20 includes a plurality of rectangular divided stages 21 arranged in a transport (X) direction and a direction Y perpendicular to the transport (X) direction. The split stage 21 has a precision levitation stage 21S provided at both ends and a high levitation stage 21H provided therebetween. R between the division stages 21 in the transport (X) direction is an inspection area for inspection described later.

The drive unit 30 includes a linear guide 31 provided along the conveyance (X) direction of the air levitation stage 20, a linear actuator 32 that travels along the linear guide 31, and a glass substrate P that is fixed to the linear actuator 32. And a linear scale 34 for detecting the position of the linear actuator 32 on the linear guide 31 (in the conveyance (X) direction).
The overall control unit 60 shown in FIG. 1 reads the position information of the linear scale 34 and controls the conveyance speed and the gripper 33.

  3A shows the configuration of the precision levitation stage 21S, and FIG. 3B shows the configuration of the high levitation upper stage 21H. As described above, the inspection is performed in the inspection region R having a width of about 40 mm between the adjacent divided stages 21. Therefore, the precision levitation stage 21 levitates the glass substrate P so that the flatness of the glass substrate P is maintained across the inspection region R. Therefore, as shown in FIG. 3 (a), the precision levitation stage 21S has a spout PA (white circle) that ejects compressed air to float the glass substrate P and a suction port that sucks the air and adsorbs the glass substrate. Alternating with PV (black circles). And the compressed air supply source 51 and the vacuum supply source 52 are controlled, and both are balanced so that the flatness of the glass substrate P may be obtained. On the other hand, as shown in FIG. 3 (b), the high flying height stage 21H has only a spout PA that ejects compressed air for levitating the glass substrate P, and stably floats the glass substrate P to increase the conveyance speed. The load is not reduced.

However, as shown in FIG. 4, the flatness of the glass substrate P collapses due to various factors.
FIG. 4 is a diagram showing the measurement result of the displacement amount (1 mm / 1 scale) of the tip Pt (see FIG. 2) of the glass substrate P from the end face of the precision stage 21S. FIG. 4A shows the measurement result of a glass substrate having an area of 880 mm × 680 mm and a thickness of 0.7 mm, and FIG. 4B shows the measurement result of a glass substrate having the same area and a thickness of 0.4 mm. . The scale of the amount of displacement on the vertical axis is 1 mm, and the measurement result at the position of the end face of the precision stage 21S is shown as a reference. Further, as will be described later, in order to show the measurement results at three positions, the positions on the chart are shifted and the absolute value is meaningless. The measurement is performed with a non-contact laser displacement meter, and the measurement conditions are a glass substrate transport speed of 250 mm / s and a sampling time of 1 ms. The measurement position is a position Ia 10 mm away from the end Ps (see FIG. 2) of the glass substrate in the Y direction perpendicular to the transport direction, and Ib and Ic further 3 mm away from the 10 mm position at a total of 3 k locations. is there.

  As can be seen from FIG. 4, there are the following three points as general trends. First, the amount of displacement is large at the central portion (Ib) and relatively small at the end portions (Ia, Ic) in the Y direction. Second, the change in displacement is large at a position about 10 mm from the end face of the precision stage 21S in the central portion (1b). Third, the thinner the glass substrate, the greater the displacement. In the glass having a thickness of 0.4 mm shown in FIG. 4B, the maximum displacement is 100 μm.

  Hereinafter, in the glass substrate defect apparatus for inspecting bubbles and scratches described as an embodiment of the present invention, the allowable flatness is, for example, about ± 50 μm and needs to be within that range.

  FIG. 5 is a diagram showing the configuration of the inspection unit 10 of the first embodiment of the glass substrate defect apparatus of the present invention that can realize this. In the present embodiment, a line sensor is used as the imaging means to be inspected, the amount of jump (displacement) of the glass substrate P at the inspection position is measured, and the position of the imaging means is always adjusted based on the amount of displacement so as to be in focus. Follow-up control to follow is performed, and although it is not actually flat, flatness is ensured in the sense that the distance is kept constant from the viewpoint of inspection.

  The inspection unit 10 includes a flaw inspection unit 10A that inspects a flaw on the glass substrate P and a bubble inspection unit 10B that inspects bubbles.

The wound inspection unit 10A is divided into an imaging unit 11A and a light source unit 16A. The imaging unit 11A measures the amount of displacement G between the line sensor 12A that detects scattered light from the front or back surface of the glass substrate P via the light receiving lens 13A and the glass substrate P that is fixed to the housing of the imaging unit 11A. 14 A of detection sensors, and the imaging part drive part 15A which raises / lowers the imaging part which comprises the line sensor 12A and the light reception lens 13A based on the detection result of the distance detection sensor 14A. In the present embodiment, a line CCD is used as the line sensor 12A for imaging a predetermined line-shaped range, and a non-contact type laser displacement meter is used as the distance detection sensor 14A.
The imaging unit driving unit 15A is provided at both ends of the motor 15Aa fixed to the housing of the imaging unit 11A, the ball joint 15Ab rotated by the driving motor 15Aa, and the ball joint 15Ab fixed to the housing of the imaging unit 13. And a nut 15Ac that is fixed to the imaging unit and moves up and down by the rotation of the ball joint 15Ab.

On the other hand, the light source unit 16A includes a laser light source 17A, a mirror 18A for obliquely irradiating laser light, and a condenser lens 19A in order to detect a scratch of about 10 μm.
With these configurations, at least the distal end portion Ptb of the glass substrate P (a certain range from the distal end Pt shown in FIG. 2) causes the imaging unit to follow displacement such as jumping (lifting) when the inspection region R is reached. By doing so, it is possible to reliably detect a flaw. Of course, not only the front end portion Ptb but also other portions may be similarly detected to control the imaging unit. In particular, since the flatness tends to be lost in the rear end portion Pbb of the glass substrate (a certain range from the rear end Pb of the glass shown in FIG. 2), the effect is high.

  On the other hand, the bubble inspection unit 10B basically has the same configuration as the flaw inspection unit 10A. The bubble inspection unit 10B detects bubbles based on luminance unevenness of the imaging result obtained by the imaging unit 12B. Therefore, an LED or a fluorescent lamp that can irradiate a wide range is used as the light source 17B. Other configurations are the same, and the image pickup means uses a line CCD in order to efficiently take an image as it moves to the glass substrate P.

  Accordingly, even in the basic inspection unit 10B, air bubbles can be reliably detected by causing the imaging unit to follow a displacement such as a jump when the tip portion Ptb of the glass substrate P comes into the inspection region R.

In the above embodiment, the flaw 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 the above-described embodiment, one inspection unit 10 is provided in the direction perpendicular to the transport (X) direction (Y), but may be provided at a plurality of locations. According to the measurement result of FIG. 4, since there is little loss of flatness at the end portion parallel to the conveyance direction of the glass substrate P, a large number of inspection units 10 may be arranged on the center side where the degree of flatness loss is large. .

  In the above embodiment, the case where a line is configured with a plurality of inspection apparatuses or processing apparatuses has been described as an example. Of course, the above-described embodiment is effective even with one inspection apparatus. FIG. 6 is a diagram showing a control method according to the second embodiment of the present invention for ensuring the flatness of the glass substrate in one glass defect inspection apparatus. In one glass defect inspection apparatus, after placing a glass substrate on a stage, it accelerates, inspects, and decelerates. This acceleration and deceleration breaks the flatness of the glass substrate P, particularly the front end portion Ptb and the rear end portion Pbb. FIG. 6A shows that the glass substrate P is accelerated at a predetermined speed before the front end Pt of the glass substrate P enters the inspection region R (time Tt) and is imaged at a predetermined timing, and the rear end portion Pbb of the glass substrate P is detected. A case where the vehicle is decelerated after passing through the inspection region R (time Tb) is shown. In FIG. 6B, the acceleration / deceleration time is relaxed and the glass substrate P is accelerated until the tip Pt of the glass substrate P enters the inspection region R or passes through the inspection region R to obtain a predetermined speed. Then, the case where the inspection is performed while decelerating before the rear end portion Pbb of the glass substrate P enters the inspection region R or after passing through the inspection region R is shown. 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 jump, that is, the amount of displacement of the glass substrate P at the time of inspection with respect to FIGS. 6 (a) and 6 (b), respectively. When the acceleration is large, the front end portion Ptb and the rear end portion Pbb of the glass substrate P jump up and become large. Although depending on the thickness of the glass substrate P, as can be seen from FIGS. 6 (c) and 6 (d), generally, when the acceleration is large, the front end portion, the rear end portion, particularly the front end portion of the glass substrate P. In this case, the amount of jumping increases.

  Therefore, the amount of displacement (the amount of jump) is measured in advance with respect to the thickness of the glass substrate P, and a speed pattern that falls within the allowable amount of displacement is obtained and used in actual inspection. If the displacement does not fall within the allowable range, the method is combined with the method shown in the first embodiment, the correction amount at the time of inspection is reduced, and the inspection is performed more stably.

  As described above, according to the second embodiment described above, since the flip-up phenomenon can be reduced or eliminated, the flatness of the glass substrate in the transport direction can be achieved, and the glass substrate can be inspected with high accuracy.

  In the embodiment described above, the inspection mainly on the front end portion or the rear end portion of the glass substrate has been mainly described. As the glass substrate is made thinner, the substrate may bounce (lift) or sink in other regions. In that case, the displacement amount may be measured over the entire region, and control for maintaining flatness may be performed.

DESCRIPTION OF SYMBOLS 10: Inspection | inspection part 10A: Scratch inspection part 10B: Bubble inspection part 11A, 11B; Imaging unit 12A, 12B: Line sensor (imaging means) 13A, 13B; Light receiving lens 14A, 14B: Distance detection sensor (non-contact type laser displacement meter) )
15A, 15B; imaging unit drive unit 16A, 16B: light source unit 17A; laser light source 18A: mirror 19A: condenser lens 20: air levitation stage 21: split stage 21S: precision levitation stage 21H: high levitation stage 30: drive unit 31: Linear guide 32: Linear actuator 33: Gripper 34: Linear scale 40: Conveying unit 50: Air supply / intake unit 51: Pressurized air supply source 52: Vacuum supply source 60: Overall control unit 100: Glass substrate defect device P: Glass Substrate PA: Pressurized air outlet PV: Air suction port Pb: Rear end of glass substrate Pbb: Rear end of glass substrate Pt: Front end of glass substrate Ptb: Front end of glass substrate R: Inspection region

Claims (10)

A glass substrate having a levitation device for levitating a glass substrate with air, a transport device for conveying the glass substrate to an inspection area without the levitation device, and an optical inspection apparatus for imaging and inspecting the glass substrate in the inspection area In defect inspection equipment,
A glass substrate defect inspection apparatus, comprising: a reduction unit that reduces a displacement amount due to a jump of an end portion of the substrate glass in a conveyance direction in the inspection region.   The reduction means includes a displacement amount measuring means for measuring the displacement amount of the glass substrate in the inspection region, and a moving means for moving the imaging means for imaging based on a detection result of the displacement amount measuring means. The glass substrate defect inspection apparatus according to claim 1.   The glass substrate defect inspection apparatus according to claim 2, wherein the displacement measuring means is a non-contact type laser displacement meter.   The glass substrate defect inspection according to claim 1, wherein a speed pattern of a conveyance speed of the glass substrate in the inspection area is determined in advance, and the glass substrate is inspected based on the predetermined speed pattern. apparatus.   5. The glass substrate defect inspection according to claim 1, wherein the optical inspection apparatus inspects at least one of bubbles in the glass substrate and scratches existing on a surface of the glass substrate. apparatus.   6. The glass substrate defect inspection according to claim 5, wherein the optical inspection apparatus includes an illuminating unit that illuminates the glass substrate at a lower portion of the transfer device and the imaging unit at an upper portion of the transfer unit. apparatus. In the glass substrate defect inspection method in which the glass substrate is lifted by generating a levitation force with air, transported to the inspection area without the levitation force, and imaging and inspecting the glass substrate in the inspection area.
A glass substrate defect inspection method, wherein the inspection is performed by reducing a displacement amount due to a jump of an end portion in the transport direction of the substrate glass in the inspection region.   The glass substrate defect inspection according to claim 7, wherein the reduction measures the amount of displacement of the glass substrate in the inspection region, and moves the imaging means for imaging based on the displacement amount measurement result. Method.   The glass substrate defect inspection method according to claim 7 or 8, wherein an acceleration of a conveyance speed of the glass substrate in the inspection region is predetermined, and the glass substrate is inspected based on the predetermined acceleration.   The glass substrate defect inspection method according to any one of claims 7 to 9, wherein at least one of bubbles in the glass substrate and scratches existing on a surface of the glass substrate are inspected.

Images