JP4626975B2 - Substrate inspection apparatus and substrate inspection method - Google Patents

Description

  The present invention relates to a substrate inspection apparatus and a substrate inspection method for detecting defects such as glass substrates and plastic substrates used in the manufacture of display panels and the like, and particularly suitable for inspection of large substrates. About.

  Manufacture of TFT (Thin Film Transistor) substrates, color filter substrates, plasma display panel substrates, organic EL (Electroluminescence) display panel substrates, etc. for liquid crystal display devices used as display panels is made by photolithography technology using glass substrates, This is performed by forming a pattern on a substrate such as a plastic substrate. At that time, if a defect such as a scratch or a foreign substance exists on the substrate, the pattern is not formed well, which causes a defect. For this reason, a substrate inspection apparatus is used to inspect defects such as scratches and foreign matter on the substrate.

The substrate inspection apparatus includes a stage on which the substrate is mounted, and an optical system that irradiates the substrate mounted on the stage with inspection light such as a laser beam and receives reflected light or scattered light from the substrate. A defect such as a scratch on the substrate or a foreign object is detected from the intensity of the reflected light or scattered light. A stage on which a substrate is mounted conventionally supports the lower surface of the substrate with a plurality of pins as described in Patent Document 1 in order to prevent the substrate from being bent.
Japanese Patent Laid-Open No. 11-59894

  In order to support the substrate flatly, the stage of the conventional substrate inspection apparatus must adjust the height of each pin so that the height of the plurality of pins supporting the lower surface of the substrate becomes uniform. There was no. In recent years, as the size of the display panel increases, the larger the substrate, the more pins are needed to support the substrate, and the adjustment of the pin height takes a long time. It was.

  An object of the present invention is to inspect the entire surface of a substrate while supporting the substrate flat without making time-consuming adjustments.

A substrate inspection apparatus of the present invention is a substrate inspection apparatus that scans a substrate with inspection light and detects a defect of the substrate, and a block that supports the lower surface of the substrate is set in a direction orthogonal to the scanning direction of the inspection light. A stage on which a substrate having a plurality of intervals and a groove in the scanning direction of inspection light formed between the blocks is mounted, and a substrate block on which a strip-shaped inspection light having a cross section shorter than the block interval is mounted on the stage The portion that is not supported by the substrate is irradiated obliquely along the scanning direction of the inspection light, and the inspection light that is transmitted through the substrate is irradiated to the bottom surface of the groove formed on the stage. An optical system having a light projecting system that is largely displaced from the position, a light receiving system that receives scattered light in which the inspection light is scattered due to a defect in the substrate, and a stage and an optical system are relatively moved to block the substrate. Unsupported part It has a moving means that scans with the inspection light emitted from the light projecting system and a plurality of lift pins that rise and fall through grooves formed in the stage, and the position of the substrate mounted on the stage is inspected by the plurality of lift pins. Substrate shift means for changing the location supported by the block of the substrate by moving the length of the cross section of the inspection light in the direction orthogonal to the light scanning direction, and substrate defects from the intensity of scattered light received by the light receiving system And a processing means for detecting.

The substrate inspection method of the present invention is a substrate inspection method for detecting a defect of a substrate by scanning the substrate with inspection light, wherein a block that supports the lower surface of the substrate is placed on the stage on which the substrate is mounted. A plurality of grooves are provided at predetermined intervals in a direction orthogonal to the scanning direction to form a groove in the scanning direction of the inspection light between the blocks, while relatively moving the stage and the optical system having the light projecting system and the light receiving system. The substrate is irradiated with a strip-shaped inspection light whose cross-sectional length is shorter than the interval between the blocks obliquely along the scanning direction of the inspection light from the light projecting system to a portion of the substrate mounted on the stage that is not supported by the block. The stage that is not supported by the block of the substrate is scanned with the inspection light while the position where the inspection light transmitted through the substrate is irradiated to the bottom surface of the groove formed on the stage is greatly shifted from the position where the inspection light is applied to the substrate. In A plurality of lift pins for raising and lowering through the form grooves, move in a direction perpendicular to the scanning direction of the inspection light the position of the substrate mounted on the stage by the length of the cross section of the inspection light, a block of substrate After changing the place to be supported, while moving the stage and the optical system relatively, the inspection light is moved from the light projecting system to the part not supported by the block of the substrate mounted on the stage in the scanning direction of the inspection light. The position where the inspection light transmitted through the substrate is irradiated to the bottom surface of the groove formed on the stage is largely supported by a new block of the substrate while largely shifting from the position where the inspection light is irradiated onto the substrate. The unexposed portion is scanned with the inspection light, the scattered light scattered by the defect of the substrate is received by the light receiving system, and the defect of the substrate is detected from the intensity of the scattered light received by the light receiving system.

A plurality of blocks supporting the lower surface of the substrate are provided on the stage on which the substrate is mounted at a predetermined interval in a direction orthogonal to the scanning direction of the inspection light . By providing a plurality of blocks at predetermined intervals in a direction perpendicular to the scanning direction of the inspection light, grooves in the scanning direction of the inspection light are formed between the blocks. The upper surface of the block provided on the stage can be cut to a uniform height by machining. Therefore, the substrate is supported flat without performing time-consuming adjustment as in the prior art.

  As a specific example, after attaching a plurality of blocks to the base, the upper surface of the blocks may be processed to a uniform height. Alternatively, a plurality of blocks may be integrated with the base by cutting grooves between the blocks, and the upper surface of the blocks may be processed to a uniform height.

In inspection, first, a strip-shaped inspection light whose cross-sectional length is shorter than the block interval is mounted on the stage from the light projecting system while relatively moving the stage and the optical system having the light projecting system and the light receiving system. The portion of the substrate that is not supported by the block is obliquely irradiated along the scanning direction of the inspection light, and the portion of the substrate that is not supported by the block is scanned by the inspection light. Since the inspection light is radiated obliquely along the scanning direction of the inspection light to the portion not supported by the block of the substrate, the inspection light is transmitted to the bottom surface of the stage groove at the position where the inspection light is irradiated to the substrate. The inspection light which is largely deviated from the position irradiated to the surface and reflected by the bottom surface of the groove does not reach the light receiving system. Subsequently, the position of the substrate mounted on the stage is moved by the length of the cross section of the inspection light in a direction orthogonal to the scanning direction of the inspection light by a plurality of lift pins that rise and fall through the grooves formed in the stage. Change the location supported by the block of the substrate. Then, in the same manner as described above, a portion of the substrate not newly supported by the block is scanned with the inspection light. Thereby, the entire surface of the substrate is inspected.

Furthermore, in the substrate inspection apparatus of the present invention, the block has a suction hole for fixing the substrate by vacuum suction. In the substrate inspection method of the present invention, the substrate is vacuum-sucked by suction holes provided in the block and fixed to the stage .

By vacuum-sucking the substrate and fixing it to the stage, even if the substrate is warped, it is corrected and the substrate is supported more flatly. In addition, since the substrate is fixed to the stage, when the stage is moved and the substrate is scanned with the inspection light, the stage can be moved at high speed.

According to the present invention, a plurality of blocks supporting the lower surface of the substrate are provided on the stage on which the substrate is mounted at a predetermined interval in a direction orthogonal to the scanning direction of the inspection light, thereby performing time-consuming adjustment as in the prior art. And the substrate can be supported flat. And, by a plurality of lift pins that rise and fall through the groove formed in the stage, the position of the substrate mounted on the stage is moved in the direction orthogonal to the scanning direction of the inspection light by the length of the cross section of the inspection light , By changing the location supported by the block of the substrate, the entire surface of the substrate can be inspected.

Furthermore, the substrate can be supported more flatly by correcting the warpage of the substrate by vacuum suctioning the substrate through the suction holes provided in the block and fixing the substrate to the stage . Further, when the stage is moved and the substrate is scanned with the inspection light, the stage can be moved at high speed.

  FIG. 1 is a top view of a substrate inspection apparatus according to an embodiment of the present invention. FIG. 2 is a side view of the substrate inspection apparatus according to the embodiment of the present invention. FIG. 3 is a front view of the substrate inspection apparatus according to the embodiment of the present invention. The substrate inspection apparatus includes an inspection table 3, legs 4, a substrate shift mechanism, a stage 10, a stage moving mechanism, optical units 20a, 20b, and 20c, and an optical unit moving mechanism. Although this embodiment shows an example in which three optical units are provided, the present invention is not limited to this, and one, two, or four or more optical units may be provided.

  2 and 3, the inspection table 3 is installed at a predetermined height by the legs 4. In FIG. 1, a stage 10 is disposed on the upper surface of the inspection table 3, and the substrate 1 is mounted on the stage 10. The stage 10 includes a stage base 11 and a block 12. The stage base 11 is a single flat plate, and on its upper surface, a plurality of rectangular blocks 12 elongated in the X direction are attached at predetermined intervals in the Y direction. By attaching the plurality of blocks 12 at a predetermined interval, elongated grooves in the X direction are formed between the blocks 12. After the block 12 is attached to the stage base 11, the upper surface is cut to a uniform height by machining. The substrate 1 mounted on the stage 10 is supported by the block 12.

  The stage base 11 may be configured by arranging a plurality of rectangular plates that are long in the Y direction at predetermined intervals in place of one flat plate. Further, the block 12 may be configured integrally with the stage base 11 by cutting a groove between the blocks 12 by machining.

  4A is an enlarged view of a part of the upper surface of the stage, and FIG. 4B is a cross-sectional view taken along the line DD in FIG. 4A. As shown in FIG. 4A, each block 12 is provided with a plurality of suction holes 13 at predetermined intervals. The suction hole 13 passes through the stage base 11 as shown in FIG. 4B, and is connected to a vacuum facility (not shown) on the lower surface of the stage base 11. By sucking air from the suction holes 13 using a vacuum facility (not shown), the substrate 1 supported by the block 12 is vacuum-sucked and fixed to the stage 10.

  A portion of the substrate 1 that is not supported by the block 12 is irradiated with inspection light 2 from optical units 20a, 20b, and 20c described later. As shown in FIG. 4A, the inspection light 2 has a strip shape in cross section. The interval between the centers of the blocks 12 is twice (2L) the length L of the cross section of the inspection light 2, and the width W of the blocks 12 is smaller than L (W <L). Note that a plurality of openings 14 are provided in a portion where the block 12 of the stage base 11 is not attached, and lift pins 9 described later are inserted into the openings 14.

  In FIG. 1, the stage moving mechanism includes an X guide 5, a ball screw 15, and a servo motor 16. A ball screw 15 is attached to the lower surface of the stage 10, and a servo motor 16 is connected to the ball screw 15. The servo motor 16 is installed in a groove 3 d provided in the inspection table 3. By rotating the ball screw 15 by the servo motor 16, the stage 10 moves in the X direction along the X guide 5 provided on the inspection table 3.

  The optical unit moving mechanism includes an X guide 6, a Y guide 7, a moving table 34, ball screws 35 and 45, and servo motors 36 and 46. Three optical units 20a, 20b, and 20c are mounted on the movable table 34. A ball screw 35 is attached to the side surface of the movable table 34, and a servo motor 36 is connected to the ball screw 35. The servo motor 36 is installed on the side surface of the inspection table 3. By rotating the ball screw 35 by the servo motor 36, the moving table 34 moves in the X direction along the X guide 6 provided on the inspection table 3.

  A ball screw 45 is attached to the optical units 20 a, 20 b, and 20 c, and a servo motor 46 is connected to the ball screw 45. The servo motor 46 is installed on the upper surface of the movable table 34. By rotating the ball screw 45 by the servo motor 46, the optical units 20a, 20b, and 20c move in the Y direction along the Y guide 7 provided on the moving table 34.

  FIG. 5 is a diagram showing a schematic configuration of the optical unit. Each of the optical units 20a, 20b, and 20c includes a light projecting system that irradiates the inspection light 2 onto the substrate 1, a reflected light detection system that receives reflected light from the substrate 1, and a light receiving system that receives scattered light from the substrate 1. It is configured to include.

  The light projecting system includes a laser light source 21, lenses 22 and 23, and a mirror 24. The laser light source 21 generates laser light that becomes inspection light 2. The lens 22 condenses the laser light generated from the laser light source 21. The lens 23 focuses the laser light collected by the lens 22. The mirror 24 obliquely irradiates the substrate 1 with the laser light focused by the lens 23 as the inspection light 2.

  A part of the inspection light 2 irradiated obliquely onto the substrate 1 is reflected by the surface of the substrate 1 and a part of the inspection light 2 is transmitted into the substrate 1. When the surface of the substrate 1 has a defect such as a scratch or a foreign substance, a part of the inspection light 2 irradiated to the substrate 1 is scattered by the defect, and scattered light is generated. A part of the inspection light 2 transmitted to the inside of the substrate 1 is reflected on the back surface of the substrate 1, and a part is emitted from the back surface of the substrate 1 to the outside. When there is a defect such as a scratch or a foreign substance on the back surface of the substrate 1, a part of the inspection light 2 transmitted to the inside of the substrate 1 is scattered by the defect, and scattered light is generated. The inspection light 2 emitted to the outside from the back surface of the substrate 1 passes through a groove formed in the stage 10 and is irradiated onto the stage base 11. Since the position at which the inspection light 2 is irradiated onto the stage base 11 is greatly shifted from the position at which the inspection light 2 is irradiated onto the substrate 1 to the right side of the drawing, the inspection light 2 reflected by the stage base 11 is reflected in the reflected light detection system and Does not reach the light receiving system.

  The reflected light detection system includes a mirror 24, a lens 25, and a CCD line sensor 26. Reflected light from the surface of the substrate 1 enters the lens 25 through the mirror 24. The lens 25 focuses the reflected light from the surface of the substrate 1 and forms an image on the light receiving surface of the CCD line sensor 26.

  At this time, the light receiving position of the reflected light on the light receiving surface of the CCD line sensor 26 varies depending on the height of the surface of the substrate 1. When the height of the surface of the substrate 1 shown in FIG. 5 is used as a reference and the height of the surface of the substrate 1 is lower than the reference, the position where the inspection light 2 is irradiated and reflected on the surface of the substrate 1 is on the right side of the drawing. The light receiving position of the reflected light on the light receiving surface of the CCD line sensor 26 moves to the left side of the drawing. Conversely, when the height of the surface of the substrate 1 is higher than the reference, the position where the inspection light 2 is irradiated and reflected on the surface of the substrate 1 moves to the left side of the drawing, and the reflected light on the light receiving surface of the CCD line sensor 26 The light receiving position moves to the right side of the drawing.

  The CCD line sensor 26 has a plurality of CCDs arranged on the light receiving surface, and outputs a detection signal corresponding to the intensity of the reflected light received on the light receiving surface to the focus adjustment control circuit 38. The focus adjustment control circuit 38 drives the focus adjustment mechanism 39 in accordance with a command from the CPU 70. For example, when inspecting a defect on the surface of the substrate 1, the focus adjustment control circuit 38 determines that reflected light from the surface of the substrate 1 is detected at the center position of the light receiving surface of the CCD line sensor 26 from the detection signal of the CCD line sensor 26. The focus adjustment mechanism 39 is driven to move the optical units 20a, 20b, and 20c so that the light is received. The focus adjustment mechanism 39 is composed of, for example, a pulse motor, and adjusts the focus position by moving the optical units 20a, 20b, and 20c up and down in accordance with the drive pulse from the focus adjustment control circuit 38.

  The light receiving system includes a condenser lens 27, an imaging lens 28, and a CCD line sensor 29. The condensing lens 27 condenses the scattered light from the front surface or the back surface of the substrate 1, and the imaging lens 28 images the scattered light collected by the condensing lens 27 on the light receiving surface of the CCD line sensor 29. . The CCD line sensor 29 has a plurality of CCDs arranged on the light receiving surface, and outputs a detection signal corresponding to the intensity of scattered light received on the light receiving surface to the signal conversion circuits 50a, 50b, and 50c.

  FIG. 6 is a diagram showing a schematic configuration of a control system and a signal processing system of the substrate inspection apparatus according to the embodiment of the present invention. The control system includes an XY movement control circuit 30, drive circuits 31, 32, and 33, the above-described focus adjustment control circuit 38, and a CPU 70.

  The XY movement control circuit 30 controls the movement of the stage 10 and the optical units 20a, 20b, and 20c in the X direction and the movement of the optical units 20a, 20b, and 20c in the Y direction according to a command from the CPU. The drive circuit 31 drives the servo motor 16 under the control of the XY movement control circuit 30 to move the stage 10 in the X direction. As the stage 10 moves in the X direction, the substrate 1 mounted on the stage 10 moves in the X direction. The drive circuit 32 drives the servo motor 36 under the control of the XY movement control circuit 30 to move the moving table 34 in the X direction. As the moving table 34 moves in the X direction, the optical units 20a, 20b, and 20c mounted on the moving table 34 move in the X direction. The drive circuit 33 drives the servo motor 46 under the control of the XY movement control circuit 30 to move the optical units 20a, 20b, and 20c in the Y direction.

  FIG. 7 is a diagram for explaining the operation of the substrate inspection apparatus according to the embodiment of the present invention. When scanning the substrate 1 with the inspection light 2 irradiated from the light projecting system of the optical units 20a, 20b, and 20c, the stage 10 and the optical units 20a, 20b, and 20c are moved in the opposite directions in the X direction, One scan is performed. FIG. 7A shows a state before movement, FIG. 7B shows a state during movement, and FIG. 7C shows a state after movement. In the present embodiment, since three optical units 20a, 20b, and 20c are provided, three scans of a portion that is not supported by the block 12 of the substrate 1 are performed by one scan.

  When one scan is completed, after the optical units 20a, 20b, and 20c are moved in the Y direction, the next scan is performed on other portions of the substrate 1 that are not supported by the block 12. By repeating these operations, all portions of the substrate 1 that are not supported by the block 12 are scanned with the inspection light 2.

  When the scanning by the inspection light 2 is completed for all the portions not supported by the block 12 of the substrate 1, the substrate inspection apparatus shifts the substrate 1 in the Y direction using the substrate shift mechanism. FIG. 8 is a diagram for explaining the operation of the substrate shift mechanism. The substrate shift mechanism includes a lift base 8 and lift pins 9.

  A lift base 8 is disposed below the inspection table 3, and a plurality of lift pins 9 are attached to the lift base 8. The inspection table 3 is provided with an opening through which the lift pins 9 pass. As shown in FIG. 8A, the plurality of lift pins 9 attached to the lift base 8 pass through the openings provided in the inspection table 3 and into the openings 14 provided in the stage base 11 (see FIG. 4). Has been inserted. The lift base 8 is moved in the Z direction by a lift mechanism (not shown), whereby the lift pin 9 is lifted and lowered through the opening provided in the inspection table 3 and the opening 14 provided in the stage base 11. Further, the elevating base 8 is moved in the Y direction by a moving mechanism (not shown), whereby the lift pin 9 is moved in the Y direction in the opening provided in the inspection table 3 and in the opening 14 provided in the stage base 11. .

  When the scanning by the inspection light 2 is completed for all the portions not supported by the block 12 of the substrate 1, the vacuum suction by the suction holes 13 (see FIG. 4) of the block 12 is released, and then the state shown in FIG. Then, the elevating base 8 is raised in the Z direction, and the substrate 1 is lifted from the block 12 by the lift pins 9.

  Next, in the state where the substrate 1 is lifted by the lift pins 9, the elevating base 8 is moved in the Y direction as shown in FIG. As a result, the substrate 1 lifted by the lift pins 9 is shifted in the Y direction. The amount of shift of the substrate 1 in the Y direction is made equal to the length L of the cross section of the inspection light 2 shown in FIG.

  When the shift of the substrate 1 in the Y direction is completed, the lift base 8 is lowered in the Z direction as shown in FIG. 8D, and the substrate 1 lifted by the lift pins 9 is placed on the block 12. And the board | substrate 1 is vacuum-sucked by the suction hole 13 (refer FIG. 4) of the block 12. FIG. At this time, since the substrate 1 is shifted by the length L of the cross section of the inspection light 2 in the Y direction, the already inspected portion of the substrate 1 is supported by the block 12 and the substrate 1 is still inspected. An unbroken portion is disposed above the groove formed in the stage 10.

  After the substrate 1 is shifted in the Y direction, one scan and the movement of the optical units 20a, 20b, and 20c in the Y direction are repeated for the portion of the substrate 1 that is not supported by the block 12 as described above. Thus, scanning with the inspection light 2 is performed.

  FIG. 9 is a diagram for explaining scanning of the substrate of the substrate inspection apparatus according to the embodiment of the present invention. FIG. 9A shows a scanning region before the substrate 1 is shifted, and FIG. 9B shows a scanning region after the substrate 1 is shifted. 9A and 9B, arrows An, Bn, and Cn (n is a natural number) indicate directions in which the inspection lights 2 of the optical units 20a, 20b, and 20c scan the substrate 1 in the n-th scanning, respectively. Show. The gray area around the arrow is the scanning area. In the present embodiment, as shown in FIG. 9A, a portion of the substrate 1 that is not supported by the block 12 before the shift is scanned by the first to sixth scans. Then, as shown in FIG. 9B, the portion of the substrate 1 that is not supported by the block 12 after the shift is scanned by the seventh to twelfth scans. Accordingly, the entire surface of the substrate 1 is scanned by a total of 12 scans, before and after the shift of the substrate 1.

  In FIG. 6, the signal processing system includes an inspection position detection circuit 40, signal conversion circuits 50a, 50b, and 50c, a signal processing circuit 60, a CPU 70, and an output device 80.

  The inspection position detection circuit 40 includes rotary encoders 17, 37, 47, counters 41, 42, 43, and an adder circuit 44. The rotary encoders 17, 37, and 47 are attached to the servomotors 16, 36, and 46, respectively, detect the rotation amounts of the servomotors 16, 36, and 46, and output pulse signals corresponding to the detected rotation amounts. . The counters 41, 42, and 43 respectively read and count the output pulses of the rotary encoders 17, 37, and 47 at a constant timing, and output the count results.

  The output of the counter 41 indicates the amount of movement of the stage 10 in the X direction, and the output of the counter 42 indicates the amount of movement of the optical units 20a, 20b, and 20c in the X direction. The inspection position detection circuit 40 adds the outputs of the counters 41 and 42 by the addition circuit 44 and detects the position in the X direction on the substrate 1 irradiated with the inspection light 2. The output of the counter 43 indicates the amount of movement of the optical units 20a, 20b, and 20c in the Y direction, whereby the inspection position detection circuit 40 is positioned in the Y direction on the substrate 1 irradiated with the inspection light 2. Is detected. The positions in the X direction and Y direction on the substrate 1 irradiated with the inspection light 2 detected by the inspection position detection circuit 40 are input to the signal processing circuit 60.

  The signal conversion circuits 50a, 50b, and 50c convert detection signals of the CCD line sensor 29 (see FIG. 5) of the optical units 20a, 20b, and 20c into digital signals and output them to the signal processing circuit 60. The signal processing circuit 60 includes an internal memory, and stores the digital signals input from the signal conversion circuits 50a, 50b, and 50c as digital data in the internal memory. At this time, the signal processing circuit 60 stores the digital data in association with the positions in the X direction and the Y direction on the substrate irradiated with the inspection light 2 input from the inspection position detection circuit 40. Then, the signal processing circuit 60 processes the digital data stored in the internal memory under the control of the CPU 70 and detects defects on the front surface or the back surface of the substrate 1 from the intensity of the scattered light received by the light receiving surface of the CCD line sensor 29. To do. The CPU 70 outputs the detection result of the signal processing circuit 60 to the output device 80 including a display and a printer.

  FIG. 10 is a top view of a substrate inspection apparatus according to another embodiment of the present invention. The optical units 20a, 20b, and 20c are not only provided close to each other as shown in FIG. 1, but also arranged in advance by shifting the width in the Y direction of the substrate 1 by an interval divided by the number of optical units as shown in FIG. However, scanning may be performed.

  FIG. 11 is a diagram for explaining scanning of a substrate in a substrate inspection apparatus according to another embodiment of the present invention. FIG. 11A shows a scanning region before the substrate 1 is shifted, and FIG. 11B shows a scanning region after the substrate 1 is shifted. 11A and 11B, arrows An, Bn, and Cn (n is a natural number) indicate directions in which the inspection light 2 of the optical units 20a, 20b, and 20c scans the substrate 1 in the n-th scanning, respectively. Show. The gray area around the arrow is the scanning area.

  According to the present embodiment, as compared with the case where the optical units 20a, 20b, and 20c are installed close to each other as shown in FIG. 1, the optical units 20a, 20b, and 20c in the Y direction after one round-trip scanning is completed. The amount of movement can be reduced.

  According to the embodiment described above, the stage 10 on which the substrate 1 is mounted is provided with a plurality of blocks 12 that support the lower surface of the substrate 1 at a predetermined interval, so that time-consuming adjustment as in the prior art is not performed. The substrate 1 can be supported flat. Then, the entire surface of the substrate 1 is inspected by shifting the substrate 1 mounted on the stage 10 in a direction perpendicular to the scanning direction of the inspection light 2 and changing the location supported by the block 12 of the substrate 1. Can do.

  Further, the substrate 1 is vacuum-sucked by the suction holes 13 provided in the block 12, whereby the warp of the substrate 1 can be corrected and the substrate 1 can be supported more flatly. Further, since the substrate 1 is fixed to the stage 10, the stage 10 can be moved at a high speed when the substrate 1 is scanned with the inspection light 2.

  In the embodiment described above, when the substrate 1 is scanned with the inspection light 2, both the stage 10 and the optical units 20a, 20b, and 20c are moved. However, the present invention relates to the stage and the optical system. The present invention is also applied to a substrate inspection apparatus that moves only one of them.

It is a top view of the board | substrate inspection apparatus by one embodiment of this invention. It is a side view of the board | substrate inspection apparatus by one embodiment of this invention. It is a front view of the board | substrate inspection apparatus by one embodiment of this invention. 4A is an enlarged view of a part of the upper surface of the stage, and FIG. 4B is a cross-sectional view taken along the line DD in FIG. 4A. It is a figure which shows schematic structure of an optical unit. It is a figure which shows schematic structure of the control system and signal processing system of the board | substrate inspection apparatus by one embodiment of this invention. It is a figure explaining operation | movement of the board | substrate inspection apparatus by one embodiment of this invention. It is a figure explaining operation | movement of a board | substrate shift mechanism. It is a figure explaining the scanning of the board | substrate of the board | substrate inspection apparatus by one embodiment of this invention. It is a top view of the board | substrate inspection apparatus by the other form of this invention. It is a figure explaining the scanning of the board | substrate of the board | substrate inspection apparatus by the other form of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Inspection light 3 Inspection table 4 Legs 5, 6 X guide 7 Y guide 8 Lifting base 9 Lift pin 10 Stage 11 Stage base 12 Block 13 Suction hole 14 Opening 15 Ball screw 16 Servo motor 17 Rotary encoder 20a, 20b, 20c Optical Unit 21 Laser light source 22, 23 Lens 24 Mirror 25 Lens 26 CCD line sensor 27 Condensing lens 28 Imaging lens 29 CCD line sensor 30 XY movement control circuits 31, 32, 33 Drive circuit 34 Moving table 35, 45 Ball screw 36, 46 Servo motors 37, 47 Rotary encoder 38 Focus adjustment control circuit 39 Focus adjustment mechanism 40 Inspection position detection circuit 41, 42, 43 Counter 44 Addition circuit 50a, 50b, 50c Signal conversion circuit 60 Signal processing circuit 70 CPU
80 output device

Claims (6)

A substrate inspection apparatus that scans a substrate with inspection light and detects a defect of the substrate,
A stage for mounting a substrate having a plurality of blocks supporting the lower surface of the substrate at a predetermined interval in a direction perpendicular to the scanning direction of the inspection light, and having a groove formed in the scanning direction of the inspection light between the blocks;
A band-shaped inspection light whose cross-section length is shorter than the interval between the blocks is irradiated obliquely along the scanning direction of the inspection light to a portion of the substrate mounted on the stage that is not supported by the block, and is transmitted through the substrate. A projection system that shifts the position where the inspection light is irradiated onto the bottom surface of the groove formed on the stage from the position where the inspection light is irradiated onto the substrate, and the inspection light receives scattered light scattered by defects on the substrate An optical system having a light receiving system to
Moving means for relatively moving the stage and the optical system, and scanning a portion of the substrate that is not supported by the block with the inspection light emitted from the light projecting system;
A cross section of the inspection light having a plurality of lift pins that rise and fall through a groove formed in the stage, and a position of the substrate mounted on the stage by the plurality of lift pins in a direction orthogonal to the scanning direction of the inspection light Substrate shift means for moving the length of the substrate and changing the place supported by the block of the substrate;
A substrate inspection apparatus comprising: processing means for detecting a defect of the substrate from the intensity of scattered light received by the light receiving system. The stage has a base that supports the plurality of blocks,
The substrate inspection apparatus according to claim 1, wherein after the plurality of blocks are attached to the base, an upper surface thereof is processed to have a uniform height. The stage has a base that supports the plurality of blocks,
The substrate inspection apparatus according to claim 1, wherein the plurality of blocks are configured integrally with the base by cutting a groove between the blocks, and the upper surface is processed to a uniform height.   The substrate inspection apparatus according to claim 1, wherein the block has a suction hole for fixing the substrate by vacuum suction. A substrate inspection method for detecting defects in a substrate by scanning the substrate with inspection light,
A plurality of blocks supporting the lower surface of the substrate are provided on the stage on which the substrate is mounted at a predetermined interval in a direction orthogonal to the scanning direction of the inspection light, and a groove in the scanning direction of the inspection light is formed between the blocks.
While relatively moving the stage and the optical system having the light projecting system and the light receiving system, a strip-shaped inspection light whose cross-sectional length is shorter than the block interval is sent from the light projecting system to the substrate block mounted on the stage. The position where the inspection light is irradiated onto the bottom surface of the groove formed on the stage is irradiated from the position where the inspection light is irradiated onto the substrate. While greatly shifting, scan the part that is not supported by the block of the substrate with inspection light,
The position of the substrate mounted on the stage is moved by the length of the cross section of the inspection light in the direction perpendicular to the scanning direction of the inspection light by a plurality of lift pins that rise and fall through the grooves formed in the stage, After changing the place supported by the block,
While relatively moving the stage and the optical system, the substrate is irradiated with inspection light obliquely along the scanning direction of the inspection light from the light projecting system to a portion not supported by the block of the substrate mounted on the stage. While the position where the inspection light transmitted through the stage is irradiated onto the bottom surface of the groove formed on the stage is greatly shifted from the position where the inspection light is irradiated onto the substrate, the part of the substrate that is not supported by the block is scanned with the inspection light. ,
The light receiving system receives the scattered light scattered by the defect of the substrate in the inspection light,
A substrate inspection method, wherein a defect of a substrate is detected from the intensity of scattered light received by a light receiving system.   6. The substrate inspection method according to claim 5, wherein the substrate is vacuum-sucked by a suction hole provided in the block and fixed to the stage.

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