JP4866782B2 - Substrate clamping mechanism and drawing system - Google Patents

Description

  The present invention relates to a substrate clamping mechanism that clamps a substrate to a stage, and a drawing system that performs drawing on a substrate while moving the stage.

  An exposure system (drawing system) that fixes a substrate (for example, a material substrate for a printed wiring board) to a stage, irradiates the exposure surface of the board while moving the stage, and forms a wiring pattern on the board is known. It has been. A CCD camera is provided on the stage movement path to capture the alignment marks (substrate position detection marks) formed on the substrate, and the substrate position is calculated based on the image data obtained by the imaging. Then, the substrate is exposed.

  In such an exposure system, when the substrate is fixed to the stage, the substrate is placed so that the center of the substrate and the center of the stage coincide with each other, and then air is sucked from a minute hole formed on the surface of the stage. The substrate is sucked and held, and each side of the substrate is clamped by a clamp bar of the substrate clamping mechanism in order to cope with the case where the substrate is warped or distorted. The exposure system is configured such that the substrate size is input in advance, and the clamp bar moves in the horizontal and vertical directions based on the input substrate size to hold the substrate from above. However, there is an error between the input substrate size and the actual substrate size, and if this error is large, it was not possible to perform clamping at an appropriate position on the substrate.

In the exposure system described in Patent Document 1, the substrate size is measured before placing the substrate on the stage, an error between the input substrate size and the measured substrate size is calculated, and the substrate placement position with respect to the stage is based on this error. It is attempted to perform clamping at an appropriate position on the substrate by adjusting.
Japanese Patent Application No. 2006-264371

  However, the exposure system described in Patent Document 1 requires a complicated measurement mechanism for measuring the substrate size, and there is a problem that the manufacturing cost of the exposure system increases.

  In the exposure system described in Patent Document 1, the substrate is placed on the stage so that the center of the substrate and the center of the stage coincide with each other, but the position of the alignment mark is determined with respect to the center of the substrate. Therefore, the alignment mark may deviate from the center of the imaging area of the CCD camera. In this case, there is a problem that the alignment mark cannot be read accurately. In order to cope with this, it is necessary to place the substrate on the stage in consideration of the position of the alignment mark (that is, the center of the substrate does not necessarily coincide with the center of the stage). It was only possible to clamp at a predetermined position on the stage, and this could not be dealt with.

  An object of the present invention is to provide a substrate clamping mechanism capable of reliably clamping a substrate even when the center of the substrate and the center of the stage do not coincide with each other, and a drawing system including the substrate clamping mechanism. .

  The present invention relates to a substrate clamping mechanism for holding and fixing a rectangular substrate placed on a stage to the stage, and is disposed on the stage so as to be substantially parallel to each side of the substrate. A clamp member that presses against the stage and clamps the substrate between the stage, a closed position that presses the clamp member against the stage and clamps the substrate, and the clamp member is separated from the stage and the substrate A clamp member opening / closing portion that moves between open positions for releasing the clamping, a retracted position in which the clamp member is retracted from an area where the substrate is placed, and a clamp that clamps the substrate using the clamp member A clamp member moving part for moving the clamp member in the open position between the positions, and the clamp member, A substrate edge sensor for detecting an edge of the plate, and a controller for controlling the clamp member moving unit based on a substrate edge detection signal of the substrate edge sensor and positioning the clamp member at the clamp position. It is characterized by providing.

  The controller moves the clamp member from the retracted position toward the clamp position by the clamp member moving unit, and stops the clamp member based on a substrate edge detection signal from the substrate edge sensor during the movement. After that, it is preferable that the clamp member is closed by the clamp member opening / closing part.

  The control unit switches the moving speed from the retracted position to the clamp position by the clamp member moving unit in two stages of an initial high-speed movement and a subsequent low-speed movement, from the high-speed movement to the low-speed movement. It is preferable to set the switching point based on substrate size information acquired in advance and substrate placement position information on the stage. As a result, the time required for the clamping operation can be shortened, and the substrate edge can be reliably detected because the substrate edge is detected during low-speed movement.

  Preferably, when a substrate edge detection signal is issued from the substrate edge sensor before the switching point, it is determined that the substrate placed on the stage is large and error processing is performed. When a substrate edge detection signal is not issued from the substrate edge sensor even after a predetermined time has elapsed from the switching point, it is preferable to determine that the substrate placed on the stage is small and perform error processing. .

  The drawing system of the present invention includes a stage moving unit that holds and fixes the substrate to the stage by the substrate clamping mechanism and moves the stage along a predetermined path, and a substrate that is provided on the predetermined path and moves. A drawing unit that sequentially draws based on the image data, a suction unit that sucks at least a peripheral portion of the drawing surface of the substrate, and a pressing unit that presses the substrate against the stage, and the substrate is placed on the stage. And a substrate transfer unit that transfers the substrate upward.

  The drawing system is provided on the predetermined path and reads an alignment mark formed on the substrate, and the alignment mark passes through the center of the imaging region of the imaging unit. It is preferable that a mounting position determination unit that determines a mounting position with respect to the stage is provided, and the substrate transport unit transports the substrate to the determined mounting position. At the determined mounting position, the center of the substrate and the center of the stage do not always coincide with each other.

  According to the substrate clamping mechanism of the present invention, even when the center of the substrate placed on the stage and the center of the stage do not coincide with each other, the end of the substrate is securely clamped, and the warpage and distortion of the substrate are ensured. It can be corrected. Since the substrate detection sensor is configured to move together with the clamp member, a moving mechanism for the substrate detection sensor is not necessary, and the manufacturing cost can be reduced.

  According to the drawing system of the present invention, the substrate can be reliably clamped even when the center of the substrate and the center of the stage do not coincide with each other, and a measurement mechanism for measuring the substrate size is not necessary. Cost can be reduced. In addition, since the center of the substrate and the center of the stage do not have to coincide with each other, it becomes possible to fix the substrate to the stage so that the alignment mark passes through the center of the imaging region of the imaging unit. The mark can be read satisfactorily, and the exposure process can be performed with high accuracy.

  In FIG. 1, an exposure system (drawing system) 10 includes a digital exposure apparatus 11 and a substrate transfer apparatus 12. The digital exposure apparatus 11 fixes a substrate 13 to a stage 14 and irradiates the substrate 13 with a light beam while moving the stage 14 to form a wiring pattern on the substrate 13. The substrate transport device 12 carries the substrate 13 carried in from a preprocessing step (not shown) into the stage 14 and carries the substrate 13 out of the stage 14. In the following, the direction in which the stage 14 moves is defined as the Y direction, the direction perpendicular to the Y direction on the horizontal plane is defined as the X direction, the direction perpendicular to the Y direction on the vertical plane is defined as the Z direction, and the Z axis The direction of rotation centered on is defined as the θ direction.

  The substrate transfer device 12 includes a carry-in unit 15, a discharge unit 16, and an auto carrier hand (hereinafter referred to as AC hand) 17. The AC hand 17 constitutes a substrate transport unit. The substrate 13 carried in from the pretreatment process is positioned and placed on the carry-in unit 15. The lower surface of the AC hand 17 has a suction mechanism (suction means) having a suction portion 7 that sucks and holds the substrate 13 by sucking air, and a pressing member 8 that can move up and down to press the substrate 13 downward. The AC hand 17 moves in the X direction and the Z direction. The AC hand 17 sucks and holds the unexposed substrate 13 placed on the carry-in unit 15 by a suction mechanism, and positions and places the sucked and held substrate 13 on the stage 14. Further, the AC hand 17 sucks and holds the exposed substrate 13 on the stage 14 by a suction mechanism, and positions and places the sucked and held substrate 13 on the discharge unit 16. For example, a conveyor mechanism is used for the carry-in unit 15 and the discharge unit 16.

  The digital exposure apparatus 11 includes a flat stage 14 on which a substrate 13 is fixed. The substrate 13 is a printed substrate or a glass substrate for a flat panel display, and a photosensitive material is applied or pasted on the surface thereof. Two guide rails 20 extend in parallel with each other along the longitudinal direction (Y direction) on the upper surface of the flat substrate 19 supported by the four legs 18.

  The base 9 is supported by a guide rail 20 so as to be reciprocally movable in the Y direction, and is driven by a stage driving unit (stage moving unit) 21 (see FIG. 5) configured by a motor or the like. The stage 14 is supported by the base 9.

  A gate-shaped gate 22 is erected on the center of the base 19 in the Y direction so as to straddle the guide rail 20, and an exposure unit (drawing unit) 23 is attached to the gate 22. The exposure unit 23 is composed of a total of 16 exposure heads 24 and is fixedly arranged on the moving path of the stage 14.

  An optical fiber 26 drawn from the light source unit 25 and a signal cable 28 drawn from the image processing unit 27 are connected to the exposure unit 23. Each exposure head 24 has a digital micromirror device (DMD), controls the DMD based on image data input from the image processing unit 27, modulates the light beam from the light source unit 25, Exposure is performed by irradiating the substrate 13.

  A gate 29 is further provided on the base 19 so as to straddle the guide rail 20 on the back side in the Y direction with respect to the gate 22. Four CCD cameras (imaging units) 30 are attached to the gate 29. These CCD cameras 30 are fixedly arranged on the moving path of the stage 14 and have a built-in strobe with a very short light emission time. These CCD cameras 30 read alignment marks (substrate position detection marks) (not shown) provided on the substrate 13, and the actual positions of the read alignment marks and the appropriate positions of the alignment marks set in advance. For detecting the amount of deviation (deviation amounts in the X, Y, and θ directions). Detecting the amount of misalignment of the alignment mark is called alignment mark measurement. Information on the amount of misalignment of the alignment mark is used for correcting exposure image data. In general, the CCD camera 30 is provided in a number corresponding to the alignment mark.

  In FIG. 2, the stage 14 is provided with a substrate clamping mechanism 40 for clamping the substrate 13. The substrate clamping mechanism 40 includes a pair of clamp bars 41A and 41B that clamp both ends of the substrate 13 in the X direction from above, and a pair of clamp bars 41C and 41D that clamp both ends of the substrate 13 in the Y direction from above. The clamp bars 41 </ b> A to 41 </ b> D have moving units (a clamp member opening / closing part and a clamp member moving part) 42 </ b> A to 42 </ b> D for sliding the clamp bars 41 </ b> A to 41 </ b> D, respectively. The clamp bars 41 </ b> A to 41 </ b> D are respectively disposed above the stage 14, and the moving units 42 </ b> A to 42 </ b> D are disposed below the stage 14.

  The clamp bars 41A and 41B are long in the Y direction and face in the X direction, and the clamp bars 41C and 41D are long in the X direction and face in the Y direction. The clamp bars 41A and 41B are shorter than the clamp bars 41C and 41D, and are configured not to interfere with each other even when a small-sized substrate is clamped.

  The clamp bar 41 </ b> A is made of a metal (for example, aluminum) clamp holder 43 and a resin-made clamp blade 44 that is fixed to an inner region (a central region of the stage 14) on the lower surface of the clamp holder 43 and contacts the surface of the substrate 13. And two support pillars 45 provided in an outer region on the lower surface of the clamp holder 43 (an outer region of the stage 14). The stage 14 has two insertion holes 47 (a total of eight) formed at predetermined intervals on each side, penetrating vertically and extending in the Y direction or the X direction from the end toward the center. The two support pillars 45 of the clamp bar 41A are inserted through the corresponding two insertion holes 47. The clamp bars 41B, 41C, 41D have the same configuration as the clamp bar 41A.

  The moving unit 42A includes a support plate 50 that supports two support columns 45, and an air cylinder 51 that slides the support plate 50 in the Z direction. The tip of the piston rod 52 of the air cylinder 51 is fixed to the lower surface of the support plate 50. Driving of the air cylinder 51 is controlled by a system control unit 53 (see FIG. 5), and the piston rod 52 is lowered and raised based on a drive signal from the system control unit 53. The movable range of the piston rod 52 is limited and stops at a predetermined position when the piston rod 52 is lowered and raised.

  When the piston rod 52 is lowered, the clamp bar 41A is lowered together with the piston rod 52, and the clamp bar 41A is pressed against the stage 14. Here, when the substrate 13 is placed on the stage 14, the substrate 13 is clamped by the clamp bar 41A. On the other hand, when the piston rod 52 rises, the clamp bar 41A rises together with the piston rod 52, and the clamp bar moves away from the stage 14 in the Z direction. The distance that the clamp bar 41 </ b> A is separated from the stage 14 is larger than the thickness of the substrate 13. The state of the clamp bar 41A when the clamp bar 41A is pressed against the stage 14 is referred to as a closed state (closed position), and the state of the clamp bar 41A when separated from the stage 14 is referred to as an open state (open position).

  The moving unit 42A further includes a driving pulley 54 and a driven pulley 55 arranged in the X direction, a timing belt 56 stretched over these pulleys 54, 55, and a belt driving motor 57 that rotates the driving pulley 54. Have. The belt drive motor 57 can rotate forward and backward and is controlled by the system control unit 53. An air cylinder 51 is attached to the timing belt 56 via an attachment portion 58. When the timing belt 56 is driven, the air cylinder 51 and the support plate 50 move in the X direction, whereby the clamp bar 41A moves in the X direction. Moving. The clamp bar 41 </ b> A slides along the support hole 45 along the insertion hole 47, and the retraction position where the support pillar 45 is located at the outer end of the insertion hole 47 and the end of the support pillar 45 inside the insertion hole 47. It moves between the center position located in the part. The position of the clamp bar 41A when the clamp bar 41A clamps the peripheral edge of the substrate 13 (any position between the retracted position and the center position) is referred to as a clamp position.

  The moving units 42B, 42C, and 42D have the same configuration as the moving unit 42A. However, the moving unit 42B moves the clamp bar 41B in the Z direction and the X direction, the moving unit 42C moves the clamp bar 41C in the Z direction and the Y direction, and the moving unit D42 moves the clamp bar 41D in the Z direction and Move in Y direction.

  2 and 3, the support plate 50 of the moving unit 42A is provided with a reflection type photosensor (substrate edge sensor) 59 for detecting the presence or absence of the substrate 13. The photo sensor 59 is attached to the support plate 50 and is provided at a position corresponding to the insertion hole 47, that is, a position where the photo sensor 59 is exposed from the insertion hole 47 when viewed from above. The photo sensor 59 has a light projecting unit that emits inspection light upward and a light receiving unit that receives the inspection light reflected on the back surface of the substrate 13. When the light receiving unit receives the inspection light, the substrate is present. A signal is output, and when the light receiving unit does not receive the inspection light, a substrate absence signal is output.

  The clamp blade 44 of the clamp bar 41A is positioned above the photosensor 59. In order to prevent the inspection light from the photosensor 59 from being reflected by the clamp blade 44 and returning toward the photosensor 59, the clamp blade 44 An inclined surface 60 is formed at a portion corresponding to the insertion hole 47. A photo sensor 59 similar to the moving unit 42A is also provided on the support plate 50 of each moving unit 42B, 42C, 42D.

  In FIG. 4, a metal reinforcing member 61 for reinforcing the stage 14 is provided on the back surface of the stage 14. The reinforcing member 61 includes a square-shaped central portion 62 and four arm portions 63 that extend radially from corner portions of the central portion 62. The central portion 62 and the four arm portions 63 are provided so as to avoid the insertion hole 47, and the moving units 42A to 42D provided under the stage 14 do not interfere with each other. The reinforcing member 61 keeps the flatness of the stage 14 high, so that the exposure process to the substrate 13 can be performed with high accuracy.

  In FIG. 5 showing the electrical configuration of the exposure system 10, the exposure system 10 is provided with a system control unit 53 electrically connected to each part of the digital exposure apparatus 11 and the substrate transport apparatus 12. The control unit 53 controls each unit in an integrated manner. The system control unit 53 controls the AC hand 17 to perform the carry-in operation and the discharge operation of the substrate 13 on the stage 14. In addition, the system control unit 53 controls the stage driving unit 21 to move the stage 14 while driving the CCD camera 30 to shoot the alignment mark and control the light source unit 25 and the image processing unit 27. Then, the exposure head 24 performs exposure processing. The operation device 70 includes a display unit and an input unit, and is operated, for example, when inputting the outer size of the substrate 13 to be exposed.

  The substrate placement position determining unit 71 places the placement position of the substrate 13 on the stage 14 (this placement position is appropriately placed so that the alignment mark of the substrate 13 passes through the center of the imaging region of the CCD camera 30 when the stage is moved. (Referred to as position). Determining the proper placement position of the substrate 13 on the stage 14 is, in other words, determining the proper position of the alignment mark on the stage 14. In the Y direction, the alignment mark can be positioned in the center of the imaging region by adjusting the imaging timing of the CCD camera 30, so the proper placement position in the Y direction is set to any position on the stage 14. In this embodiment, the proper placement position in the Y direction is set to a position where the center of the substrate 13 and the center of the stage 14 coincide.

  The substrate placement position determination unit 71 calculates an appropriate placement position of the substrate in the X direction (appropriate position of the alignment mark) based on information obtained by a preparatory operation performed before performing an exposure operation on the substrate 13. ing. In this preparatory operation, the substrate 13 is placed at an appropriate position on the stage 14 in the X direction (they are placed with the center of the substrate 13 and the center of the stage 14 aligned in the Y direction) and then the CCD camera 30. The alignment mark is imaged, the amount of deviation between the center position of the imaging region in the X direction and the position of the alignment mark is calculated, and the proper placement position of the substrate in the X direction is calculated based on this amount of deviation. In the preparation operation, an appropriate placement position can be obtained more accurately by performing this process on a plurality of (for example, five) substrates. In this preparation operation, the photographing timing of the CCD camera 30 is also determined. The calculated proper placement position information and imaging timing information of the substrate are sent to the system control unit 53 and stored in the system control unit 53.

  The movement control unit (control unit) 72 controls driving of the movement units 42 </ b> A to 42 </ b> D based on instructions from the system control unit 53. The movement control unit 72 monitors a signal (substrate presence signal or substrate absence signal) from the photosensor 59 of the movement units 42A to 42D, and based on this signal, the air cylinder 51 and belt drive of the movement units 42A to 42D. The drive of the motor 57 is controlled to cause the clamp bars 41A to 41D to perform a clamp operation.

  In the movement control unit 72, the substrate 13 is placed in the region on the stage 14 based on the substrate size information input from the operation device 70 and the proper placement position information of the substrate calculated by the preparation operation. An area is estimated, and the moving speed of the clamp bar 41A is switched between high speed and low speed based on the estimated area. Specifically, on the stage 14, the high speed movement is set outside the position (see FIG. 3) away from the periphery of the substrate 13 by the distance L1 (for example, 40 mm), and the low speed movement is set inside the position. ing. Thereby, since the detection of the board | substrate 13 is performed at the time of low speed movement, the board | substrate 13 can be detected reliably. Note that a position away from the periphery of the substrate 13 by a distance L1 is referred to as a deceleration position (switching point). The clamp bar 41A stops at a clamp position that enters a predetermined distance (for example, 5 mm) from the position where the substrate 13 is detected, and performs clamping at this clamp position. This clamping position is a position where the support column 45 of the clamp bar 41 </ b> A does not contact the edge of the substrate 13.

  When the substrate 13 is detected when the clamp bar 41A is moving at a high speed, the movement control unit 72 determines that the actual substrate size is larger than the input substrate size and moves the clamp bar 41A. Is immediately stopped and an abnormal signal is output to the system control unit 53. Upon receiving the abnormality signal, the system control unit 53 displays an error indicating that the substrate size is large on the display unit of the operation device 70. A warning sound may be emitted instead of the error display.

  Further, the movement control unit 72 determines that the actual substrate size is smaller than the input substrate size when the clamp bar 41A moves at a low speed and the low-speed movement is continued for a predetermined time without detecting the substrate 13. Then, it is determined that the substrate is not placed, and the movement of the clamp bar 41A is immediately stopped and an abnormal signal is output to the system control unit 53. In response to the abnormal signal, the system control unit 53 displays an error indicating that the substrate size is small or the substrate is not placed on the display unit of the operation device 70. The movement control unit 72 performs the same control as the movement unit 42A for the movement units 42B, 42C, and 42D.

  Hereinafter, the operation of the above configuration will be described. When the operation device 70 is operated and a substrate size is input, the substrate size information is stored in the system control unit 53. In addition, a preparatory operation is performed before performing an exposure operation on the substrate 13, an appropriate placement position of the substrate with respect to the stage 14 is calculated, and the appropriate placement position information of the substrate is stored in the system control unit 53.

  After the preparatory operation is completed, the unexposed substrate 13 on which the AC hand 17 is positioned and placed on the carry-in portion 15 is held by the suction portion 7 of the suction mechanism, and this substrate 13 is placed on the stage 14 based on the appropriate placement position information. Then, the suction by the suction portion 7 is released and the substrate 13 is pressed against the stage 14 by the pressing member 8 of the pressing mechanism. When the substrate 13 is placed in a state of being pressed against the stage 14, a clamp start signal is issued from the system control unit 53, and the movement control unit 72 controls the driving of the movement units 42A to 42D to start the clamping operation. The

  Hereinafter, the clamping operation will be described along the flow of the flowchart of FIG. In response to the clamp start signal, the movement control unit 72 drives the air cylinders 51 of the movement units 42A to 42D to open the clamp bars 41A to 41D, respectively. In addition, the movement control unit 72 receives a clamp start signal and calculates a high-speed movement region and a low-speed movement region on the stage 14 based on the substrate size information and the proper placement position information of the substrate. All the photosensors 59 of the moving units 42A to 42D output a no-board signal.

  When the clamp bar 41A is in the high speed movement region when the clamp start signal is received, the movement control unit 72 rotates the belt drive motor 57 of the moving unit 42A at a high speed to move the clamp bar 41A toward the center position at a high speed. Let When the clamp bar 41A reaches the deceleration position in the middle of movement, the belt drive motor 57 is changed to low speed rotation and the clamp bar 41A moves at low speed. On the other hand, when the photosensor 59 outputs a substrate presence signal while the clamp bar 41A is moving at a high speed, an error message indicating that the substrate size is large is displayed on the display unit of the operating device 70.

  When the clamp bar 41A is in the low speed movement region when the clamp start signal is received, the movement control unit 72 rotates the belt drive motor 57 at a low speed to move the clamp bar 41A at a low speed toward the center position.

  If the photo sensor 59 outputs a substrate presence signal while the clamp bar 41A is moving at a low speed, the clamp bar 41A is stopped at a clamp position that enters a predetermined distance from the detection position. The graph in FIG. 7 shows the relationship between time and the moving speed of the clamp bar 41A. On the other hand, when the clamp bar 41A moves at a low speed and the photo sensor 59 continues to output the no-substrate signal for a predetermined time, the fact that the substrate size is small or the substrate is placed on the display unit of the operating device 70. An error message indicating that it has not been displayed. The clamp bars 41B, 41C, 41D perform the same operation simultaneously with the clamp bar 41A.

  When all of the clamp bars 41A to 41D stop at the clamp position, the air cylinders 51 of the moving units 42A to 42D are driven, and the clamp bars 41A to 41D are simultaneously closed. Since the center of the substrate 13 and the center of the stage 14 do not match in the X direction, the movement amounts of the clamp bar 41A and the clamp bar 41B are different from each other. The four sides of the substrate 13 are clamped by the clamp bars 41A to 41D, and this is corrected even when the substrate 13 is warped or distorted. When the substrate 13 is clamped, the pressing operation by the pressing member 8 of the AC hand 17 is released and the AC hand 17 is separated from the substrate 13.

  Simultaneously with the clamping operation by the substrate clamping mechanism 40, air is sucked from the hole formed in the surface of the stage 14, and the substrate 13 is sucked and held on the stage 14.

  Thereafter, the stage 14 moves backward (Y direction), and the alignment mark of the substrate 13 fixed to the stage 14 is imaged by the CCD camera 30. The alignment mark is reliably imaged at the center of the imaging area of the CCD camera 30. The captured image data of the CCD camera 30 is sent to the image processing unit 27, and the actual position of the alignment mark is calculated from the captured image data. Further, the actual position of the alignment mark and the appropriate placement position of the substrate (that is, alignment) The position shift amount is calculated by comparing with the appropriate position of the mark, and this position shift amount information is used for correcting the exposure image data.

  After imaging by the CCD camera 30, the stage 14 moves forward (Y direction), and the light source unit 25 and the image processing unit 27 are controlled based on the corrected exposure image data in accordance with the movement of the stage 14, and the substrate. 13 is an exposure process.

  When the stage 14 moves most forward, the air cylinders 51 of the moving units 42A to 42D are driven, and the clamp bars 41A to 41D are changed from the closed state to the open state, respectively, and the air suction from the holes of the stage 14 is stopped. Thus, the suction holding is released. The clamp bars 41A to 41D may be moved from the clamp position to the retracted position, or may be moved to a position slightly away from the clamp position. The exposed substrate 13 is conveyed from the stage 14 to the discharge unit 16 by the AC hand 17. Thereafter, the above-described carry-in operation, clamp operation, exposure operation, and carry-out operation are repeated.

  According to the substrate clamping mechanism 40 of the present invention, even when the center of the substrate 13 and the center of the stage 14 do not coincide with each other, the peripheral portion of the substrate 13 is securely clamped, and the warpage and distortion of the substrate 13 are ensured. Can be corrected. The photo sensor (substrate edge sensor) 59 is configured to move together with the clamp bars 41 </ b> A to 41 </ b> D, and a moving mechanism for the photo sensor 59 is not necessary, so that the manufacturing cost of the substrate clamp mechanism 40 can be suppressed.

  Further, according to the digital exposure apparatus 11 of the present invention, the substrate 13 can be reliably clamped even when the center of the substrate 13 and the center of the stage 14 do not coincide with each other. There is no need to provide a measurement mechanism for measuring the size, and the manufacturing cost can be reduced. In addition, since the substrate 13 can be fixed to the stage 14 so that the alignment mark passes through the center of the imaging area of the CCD camera 30, the alignment mark can be read accurately.

  In the above embodiment, the clamp bars 41C and 41D are moved independently. However, when the center of the substrate 13 and the center of the stage 14 are aligned in the Y direction, the clamp bars 41C and 41D are independent if they can be moved symmetrically. The timing belt 56 and the belt drive motor 57 may be shared. Since one set of timing belt and belt drive motor is not required, the manufacturing cost can be reduced.

  The configuration of the moving unit is not limited to the above embodiment, and may be other configurations as long as the clamp bar can be slid. In addition to the air cylinder mechanism and the belt mechanism described in the above embodiment, other mechanisms such as a ball screw mechanism can be used.

  In the above embodiment, four clamp bars are used, but three or less may be used. In the above embodiment, the shape of the clamp bar is I-shaped, but other shapes such as L-shape and U-shape may be used.

  The substrate clamping mechanism described in the above embodiment can be applied to systems other than the exposure system, for example, a substrate inspection system that optically inspects the appearance of the substrate. In the above embodiment, the exposure system that irradiates the substrate by irradiating the light beam modulated based on the image data has been described. However, dot-like ink is ejected based on the image data to draw on the substrate. The present invention can also be applied to an ink jet drawing system.

It is an external appearance perspective view of an exposure system. It is a disassembled perspective view of a stage and a substrate clamp mechanism. It is a figure which shows a stage and a reinforcement member. It is sectional drawing which shows the structure of a clamp bar vicinity. It is a block diagram which shows the electric constitution of an exposure system. It is a flowchart which shows the flow of a clamp operation | movement. It is a graph which shows the change of the moving speed of a clamp bar.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Exposure system 11 Digital exposure apparatus 12 Substrate conveyance apparatus 13 Substrate 14 Stage 17 AC hand 21 Stage drive part 30 CCD camera 40 Substrate clamp mechanism 41A, 41B, 41C, 41D Clamp bar 42A, 42B, 42C, 42D Moving unit 59 Photosensor 53 System Control Unit 71 Substrate Placement Position Determination Unit 72 Movement Control Unit

Claims (7)

In the substrate clamping mechanism for holding and fixing the rectangular substrate placed on the stage to the stage,
A clamp member that is disposed on the stage so as to be substantially parallel to each side of the substrate, and holds the substrate between the stage by pressing each side of the substrate against the stage;
A clamp member opening / closing portion that moves between a closed position that presses the clamp member against the stage and clamps the substrate, and an open position that releases the clamp of the substrate by separating the clamp member from the stage;
A clamp that moves the clamp member in the open position between a retracted position in which the clamp member is retracted from an area where the substrate is placed and a clamp position in which the substrate is clamped using the clamp member. A member moving part;
A substrate edge sensor that moves with the clamp member and detects an edge of the substrate;
A control unit for controlling the clamp member moving unit based on a substrate edge detection signal of the substrate edge sensor and positioning the clamp member at the clamp position;
A substrate clamping mechanism comprising:   The controller moves the clamp member from the retracted position toward the clamp position by the clamp member moving unit, and stops the clamp member based on a substrate edge detection signal from the substrate edge sensor during the movement. 2. The substrate clamping mechanism according to claim 1, wherein after that, the clamp member is closed by the clamp member opening / closing part.   The control unit switches the moving speed from the retracted position to the clamp position by the clamp member moving unit in two stages of an initial high-speed movement and a subsequent low-speed movement, from the high-speed movement to the low-speed movement. The substrate clamping mechanism according to claim 2, wherein the switching point is set based on substrate size information acquired in advance and substrate placement position information on the stage.   4. The error processing is performed when it is determined that the substrate placed on the stage is large when a substrate edge detection signal is issued from the substrate edge sensor before the switching point. PCB clamp mechanism.   When a substrate edge detection signal is not issued from the substrate edge sensor even after a predetermined time has elapsed from the switching point, it is determined that the substrate placed on the stage is small or the substrate is not placed. 5. The substrate clamping mechanism according to claim 3, wherein error processing is performed. A stage moving unit that holds and fixes the substrate to the stage by the substrate clamping mechanism according to any one of claims 1 to 5, and moves the stage along a predetermined path,
A drawing unit that is provided on the predetermined path and draws sequentially on the moving substrate based on image data;
A suction means for sucking at least a peripheral portion of the drawing surface of the substrate, and a pressing means for pressing the substrate against the stage, and a substrate transport portion for transporting the substrate onto the stage;
A drawing system comprising: The drawing system according to claim 6.
An imaging unit that is provided on the predetermined path and reads an alignment mark formed on the substrate;
A mounting position determination unit that determines a mounting position of the substrate with respect to the stage so that the alignment mark passes through a central portion of the imaging region of the imaging unit;
The drawing system, wherein the substrate transport unit transports the substrate to a determined placement position.

Images