JP6673753B2 - Substrate clamping device and substrate processing device - Google Patents

Description

  The present invention relates to an edge clamp type substrate clamping apparatus for sandwiching and fixing a pair of opposing sides of a rectangular substrate and a substrate processing apparatus to which the same is applied.

  For example, in a substrate processing apparatus such as a screen printing apparatus for applying a solder paste on a printed board, the board is fixed in a position where printing is performed and is aligned with a mask sheet. Since the mask sheet is arranged on the substrate, an edge clamp method using a pair of clamp pieces is employed for fixing the substrate. In general, in the edge clamp system, a fixed clamp is arranged on one side and a movable clamp is arranged on the other side of a pair of opposing sides of a rectangular substrate. By moving the movable clamp in a direction approaching the fixed clamp, the substrate is fixed by sandwiching (clamping) the pair of side edges.

  The clamping force of the substrate by the pair of clamp pieces needs to be set appropriately. If the clamping force is too strong, the clamped substrate may be warped, or in extreme cases, the substrate may be damaged such as cracking. On the other hand, if the clamping force is too weak, the position of the clamped substrate is displaced, and the position of the substrate is displaced from the mask sheet or the substrate is dropped. In view of these points, Patent Literature 1 discloses a substrate clamping device in which an appropriate clamping force is set according to the material, thickness, and size of a substrate.

JP 2011-204908 A

  In a screen printing apparatus, alignment between a mask sheet and a substrate is required. For this reason, the pair of clamp pieces are supported by a table movable in the XYZR direction, and the table is moved in the required XYZR axis direction while the substrate is clamped by the pair of clamp pieces for the alignment. Here, even when the substrate can be clamped satisfactorily in the stationary state, the pair of clamp pieces move together with the table, so that the clamped substrate is displaced, and the position of the substrate is displaced from the mask sheet or the substrate is displaced. May fall down. The above-mentioned Patent Document 1 does not consider measures for this point.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a substrate clamping apparatus that can appropriately fix a substrate even when a pair of clamp pieces move in an edge clamp type substrate clamping apparatus, and a substrate processing apparatus to which the substrate clamping apparatus is applied. It is in.

A substrate clamping device according to one aspect of the present invention includes a pair of clamp pieces that clamp and fix a pair of opposing sides of a rectangular substrate, and supports the pair of clamp pieces and moves in a predetermined axial direction. A possible table, at least one of the pair of clamp pieces, a clamp driving unit that drives the substrate in a direction to clamp the substrate and in a direction to release the clamp, and an axis driving unit that moves the table in the axial direction. A storage unit that stores a parameter relating to the clamping force of the substrate by the pair of clamp pieces in association with a substrate to be clamped, and controls the clamp driving unit with reference to the parameter, and operates the axis driving unit. A control unit that controls the table, wherein the control unit controls the table in a state where the substrate is clamped by the pair of clamp pieces. Wherein the parameter is S, a compressive stress applied to the substrate at the time of clamping the substrate, A is a first stress at which the substrate begins to be warped by the compressive stress, and A is a pair of the pair. When the table is moved in the axial direction in a state where the substrate is clamped by the clamp pieces, a second stress B at which the displacement of the fixed state of the substrate by the pair of clamp pieces starts to occur due to the moving force. When
B <S <A (1)
Are set so as to satisfy the relationship.

  According to this substrate clamping device, not only the first stress A at which the substrate starts to warp, but also the second stress at which a displacement of the fixed state of the substrate occurs when the table is moved while the substrate is clamped. In consideration of B, the clamping force of the substrate by the pair of clamp pieces is set. Therefore, not only does the substrate not warp or break due to the clamp, but also when the pair of clamp pieces are moved together with the table by the shaft drive unit, the substrate can be prevented from being misaligned or dropped.

Furthermore , when the axial moving force is set to a predetermined first moving force, the control unit reduces the axial moving force when the relationship of B <A is not established for the substrate to be clamped. the smaller than the first moving force, and, in the second moving force relationship B <a is satisfied, that controls the shaft driving unit so as to move the table.

  Depending on the material and thickness of the substrate, a case where the relationship of B <A may not be established may occur. For example, there is a case where the substrate is considerably thin and a warp or a crack is generated in the substrate if a clamping force that satisfies the second stress B required for moving the substrate in the clamped state at a normal speed is set. . According to the above-described substrate clamping device, in such a case, the control unit sets B <A by setting, for example, the axial acceleration and the moving speed to be smaller than normal and the moving force in the axial direction to be smaller. Create relationships. Therefore, even in the above case, the substrate in the clamped state can be moved.

A substrate clamping device according to another aspect of the present invention is the substrate clamping device similar to the above, wherein the substrate to be clamped has a shape characteristic that varies a warp occurrence state, applies the equation (1) above was modified according to the value of a in the shape characteristic, it intends row the process of resetting the parameters. In this case, it is preferable that the shape characteristics include a warpage amount and a warping direction of the substrate before being clamped by the pair of clamp pieces, and a notch or slit amount with respect to the substrate.

  For example, when the substrate has a shape feature such as a case where the substrate has a relatively large cutout or slit, or a case where the substrate is originally warped, the clamping force is applied. The occurrence situation of the warpage of the substrate at the time varies. According to the above substrate clamping device, the control unit corrects the value of A in the above case. Therefore, even when the substrate has the above-mentioned feature, the substrate can be properly clamped.

Substrate clamping apparatus according to still another aspect of the present invention based on the same substrate clamping device, further comprising a measuring means for detecting the amount of warpage of the substrate, wherein, the parameters are stored in the storage unit For an unknown substrate that has not been clamped, the pair of clamp pieces are used to actually perform the clamping, and the measuring unit monitors the amount of warpage generated in the unknown substrate by the clamp. to detect the value of a for the substrate, the parameters set by applying the equation (1) by the value of the resulting a, that stores in the storage unit.

  According to this substrate clamping device, the value of A is set based on the result of actually clamping the substrate with a pair of clamp pieces. Therefore, the value of A according to the actual state of the substrate can be set so that the substrate does not warp during clamping.

In a substrate clamping apparatus according to still another aspect of the present invention, in the substrate clamping apparatus similar to the above, the substrate includes a mark for positioning, and a deviation from a reference position of the substrate is obtained by imaging the mark. The control unit further comprises: a control unit configured to control the table with the substrate being clamped by the pair of clamp pieces for an unknown substrate whose parameters are not stored in the storage unit. While moving in the axial direction, the position measuring means monitors the amount of displacement of the unknown substrate in the fixed state when moving in the axial direction, and from the result of the monitoring, the value of B for the unknown substrate is calculated. detection, and the parameters set by applying the equation (1) by the value of the resulting B, that stores in the storage unit.

  According to this substrate clamping apparatus, the value of B is set based on the result of monitoring the displacement of the fixed state at that time while moving the table while the substrate is actually clamped by the pair of clamp pieces. Therefore, the value of B according to the actual state of the substrate can be set so that the substrate does not shift or drop when the substrate is moved in the clamped state. Also, for example, a screen printing apparatus or the like includes an imaging camera for a substrate, and a substrate carried into the device generally includes a positioning mark such as a fiducial mark. If the imaging camera is used as a position measuring unit and the fiducial mark is imaged, the amount of deviation can be monitored without requiring any additional device.

  A substrate processing apparatus according to another aspect of the present invention includes a processing unit that performs a predetermined process on a substrate, and the above-described substrate clamping device that clamps the substrate.

  ADVANTAGE OF THE INVENTION According to this invention, in the board | substrate clamp apparatus of an edge clamp system, even if a pair of clamp pieces move, the board | substrate clamp apparatus which can fix a board | substrate appropriately, and a substrate processing apparatus to which this was applied are provided. be able to.

FIG. 1 is a schematic side view of a screen printing apparatus to which a substrate clamping device according to the present invention is applied. FIG. 2 is a front view of the screen printing apparatus. FIG. 3 is a perspective view of the screen printing apparatus without a squeegee unit. FIG. 4 is a schematic diagram of the substrate holding mechanism (backup unit and clamp unit) according to the first embodiment. FIG. 5 is a schematic view of the substrate clamping device. FIG. 6 is a schematic view of the substrate clamping device. FIG. 7 is a schematic view of the substrate clamping device. FIG. 8 is a block diagram showing an electrical configuration of the screen printing apparatus. FIG. 9 is a schematic diagram for explaining the edge clamping force on the substrate. FIG. 10 is a diagram schematically showing a moving force acting on a clamped substrate. FIG. 11 is a graph showing an example of a limit value of warpage due to edge clamping force and substrate thickness. FIG. 12 is a graph showing an example of the force applied to the substrate by the table axis acceleration. FIGS. 13A and 13B are schematic diagrams showing a clamping situation in the case where a warp exists in the substrate. FIG. 14A illustrates an example of a substrate provided with a notch, and FIG. 14B illustrates an example of a substrate provided with a slit. FIG. 15 is a schematic diagram of a substrate holding mechanism according to the second embodiment. FIG. 16 is a diagram illustrating a case where a shift occurs in the fixed state of the substrate.

[Overall structure of screen printing device]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, a screen printing apparatus 1 (substrate processing apparatus) to which a substrate clamping apparatus according to the present invention is applied will be described with reference to FIGS. FIG. 1 is a schematic side view of the screen printing apparatus 1, FIG. 2 is a front view thereof, and FIG. 3 is a perspective view of the screen printing apparatus 1 omitting a squeegee unit 70. The screen printing apparatus 1 is an apparatus that receives a rectangular substrate P such as a printed circuit board, applies a solder paste or the like to the surface of the substrate P (predetermined processing), and then carries out the substrate. 1 to 3 and FIG. 4, which will be described later, are provided with XYZ axis direction indications. In this direction display, the transport direction of the substrate P (the direction of the arrow shown in FIG. 2) is orthogonal to the X-axis direction, the direction orthogonal to the X-axis on the horizontal plane is the Y-axis direction, and both the X-axis and the Y-axis directions are orthogonal The direction of the movement is defined as the Z-axis direction.

  The screen printing apparatus 1 includes a base 10, a printing stage ST (processing unit) on which screen printing of solder paste is performed, a 4-axis unit 20 (axis driving unit) mounted on the base 10, A backup unit 40 and a clamp unit 50 (substrate clamping device) supported by the unit 20 and constituting a part of the printing stage ST, and a mask holding unit 60 and a squeegee unit 70 arranged on the printing stage ST are provided. I have.

  The base 10 is a rectangular portion that forms the base of the screen printing device 1. The printing stage ST is disposed above the base 10 near the center of the XY axes. An entrance frame 11 and an exit frame 12 are erected on a pair of sides of the base 10 in the X-axis direction. The entrance frame 11 is provided with an opening for carrying the substrate P to be subjected to the printing process into the screen printing apparatus 1, and the exit frame 12 is provided with an opening for carrying the substrate P after the printing process. An upstream conveyor 15 for carrying the substrate P into the printing stage ST is arranged in the opening of the entrance frame 11. A downstream conveyor 16 that carries out the substrate P from the printing stage ST is disposed at an opening of the exit frame 12.

  The printing stage ST is a portion where a printing process is performed, and is a portion that is positioned from below the mask sheet 61 by the four-axis unit 20 while holding the substrate P. The printing stage ST includes a main conveyor 31, a backup unit 40, and a clamp unit 50. These components will be described later in detail.

  The four-axis unit 20 includes a Y-rail 21, a Y-axis table 22, an X-rail 23, an X-axis table 24, a rotating unit 25, an R-axis table 26, a slide column 27, a support table 28 (table), and a ball screw mechanism 29. Including. The print stage ST can be moved by the four-axis unit 20 in four axial directions of an X axis, a Y axis, a Z axis, and an R axis which is a rotation axis.

  The Y rail 21 extends on the base 10 along the Y-axis direction. The Y-axis table 22 is slidably attached to the Y-rail 21. The Y-axis table 22 is connected to a Y-axis ball screw mechanism (not shown) arranged on the base 10. The Y-axis ball screw mechanism includes a Y-axis servo motor 832 (FIG. 8), and the Y-axis table 22 moves in the Y-axis direction with respect to the base 10 by driving of the Y-axis servo motor 832.

  The X rail 23 extends on the Y-axis table 22 along the X-axis direction. The X-axis table 24 is slidably attached to the X rail 23. An X-axis ball screw mechanism (not shown) arranged on the Y-axis table 22 is connected to the X-axis table 24. The X-axis ball screw mechanism includes an X-axis servomotor 831 (FIG. 8), and the X-axis table 24 moves in the X-axis direction with respect to the Y-axis table 22 by driving the X-axis servomotor 831.

  The R-axis table 26 is attached to the X-axis table 24 via the rotation unit 25. The rotating part 25 is a member for assembling the R-axis table 26 to the X-axis table 24 so as to be rotatable around the Z-axis. An unillustrated R-axis rotation mechanism arranged on the X-axis table 24 is connected to the R-axis table 26. The R-axis rotation mechanism includes an R-axis servo motor 834 (FIG. 8), and the R-axis servo motor 834 drives the R-axis table 26 to rotate around the Z-axis with respect to the X-axis table 24.

  The slide columns 27 are a pair of columns extending in the Z-axis direction, and vertically penetrate both ends of the R-axis table 26 in the Y direction. A support table 28 is attached to the upper end of the slide column 27. The ball screw mechanism 29 is assembled between the support table 28 and the R-axis table 26. Specifically, the ball screw of the ball screw mechanism 29 extends in the Z direction, and the upper end of the ball screw is supported by the support table 28. On the R-axis table 26, a nut portion screwed to the ball screw is mounted. The ball screw mechanism 29 includes a Z-axis servomotor 833 (FIG. 8) as a driving source. The driving of the Z-axis servomotor 833 causes the support table 28 to move in the Z-axis direction with respect to the R-axis table 26 while being guided by the slide columns 27.

  X-axis, Y-axis, Z-axis, and R-axis servo motors 831, 832, 833, and 834 (axis driving units that move the tables in the axial direction) individually drive the tables 22, 24, 26, and 28. Accordingly, the uppermost support table 28 of the four-axis unit 20 can move in the X-axis, Y-axis, Z-axis, and R-axis (rotation around the Z-axis) axial direction (predetermined axial direction). The main conveyor 31, the backup unit 40, and the clamp unit 50 which constitute the printing stage ST are supported by the support table.

  The main conveyor 31 is disposed between the upstream conveyor 15 and the downstream conveyor 16 and forms a transport line for transporting the substrate P in the X-axis direction together with the conveyors 15 and 16, while being integrated with the support table 28. Move to the print processing position. That is, when the support table 28 is at the predetermined home position, the main conveyor 31 is aligned with the upstream conveyor 15 and the downstream conveyor 16 in the X-axis direction. The home position is a position where the support table 28 is lowered to the lower end, and is a predetermined origin position in the X-axis, Y-axis, and R-axis directions. When the substrate P is carried into the printing stage ST by the upstream conveyor 15 and when the substrate P is carried out of the printing stage ST by the downstream conveyor 16, the support table 28 is positioned at the home position. . On the other hand, when the printing process is performed on the substrate P, the substrate P moves out of the line of the upstream conveyor 15 and the downstream conveyor 16 and moves upward together with the support table 28.

  The main conveyor 31 includes a pair of belt conveyors 32 that respectively support the lower surfaces of both end portions of the substrate P. Similarly, the upstream conveyor 15 and the downstream conveyor 16 include a pair of belt conveyors 32. The belt conveyor 32 is driven by a drive mechanism including a substrate transport motor 84 (FIG. 8), and transports the substrate P in the X-axis direction. The interval between the pair of belt conveyors 32 can be changed by a variable mechanism (not shown). For example, the variable mechanism moves the left belt conveyor 32 toward and away from the belt conveyor 32 located on the right side of FIG. This makes it possible to transfer substrates P having different sizes on the transfer line.

  The backup unit 40 is assembled on the support table 28, and supports the substrate P by lifting it from the back side. When the printing process is performed, the back side of the substrate P is supported by the backup unit 40, so that the stationary state of the substrate P in the vertical direction is stabilized. The clamp unit 50 fixes the substrate P by sandwiching a pair of opposing sides of the substrate P. At the time of the printing process, the fixing member cannot be arranged on the upper surface side of the substrate P because the mask sheet 61 is overlaid on the substrate P. Therefore, the horizontal stationary state of the substrate P is stabilized by sandwiching and fixing the pair of sides (the pair of sides extending in the X-axis direction in the present embodiment) of the substrate P with the clamp unit 50. The substrate holding mechanism including the backup unit 40 and the clamp unit 50 will be described later in detail with reference to FIGS.

  On the support table 28, a correction mechanism 33 is further mounted. The straightening mechanism 33 is a mechanism for correcting the warpage of the substrate P and positioning the substrate P before the substrate P is clamped by the clamp unit 50. Here, the warpage of the substrate P is a warp that is convexly curved downward. The correction mechanism 33 includes a pair of pressing pieces 34 for applying a reaction force to the substrate P from above. Each pressing piece 34 is movable between an operating position where it can be pressed against the upper surface of the side end portion of the substrate P and a retracted position where it is retracted outside the operation area of the clamp unit 50. The pressing piece 34 is moved to the operation position, and the support table 28 is raised to press the substrate P against the pressing piece 34, so that the warpage of the substrate P is corrected. In addition, in addition to the above-mentioned correction mechanism 33, a mechanism for correcting a warp curved upward on the substrate P may be added.

  The mask holding unit 60 detachably holds the mask sheet 61, and includes a mask support 62, a rail 63, and a mask clamp mechanism 64. The mask sheet 61 includes, for example, a mask sheet main body formed of a rectangular metal plate such as SUS having a printing opening formed therein, and a mask holder formed of a rectangular frame holding an edge of the mask sheet main body.

  The mask support 62 is a plate-like member extending in the Y-axis direction, and supports both ends of the mask sheet 61 in the X-axis direction from below. The mask support 62 is placed on a bracket 13 projecting horizontally from the inner surface of the entrance frame 11 and on a similar bracket 14 of the exit frame 12. The rails 63 are provided on the brackets 13 and 14, respectively, and extend in the X-axis direction. The mask support 62 is supported by rails 63. The mask support 62 can slide on the rail 63 in the X-axis direction by a drive mechanism (not shown). The mask clamp mechanism 64 is assembled to each mask support 62 and clamps and fixes both ends in the X-axis direction of the mask sheet 61 from the upper surface side.

  The squeegee unit 70 is a unit that performs printing (application) processing of the solder paste, and includes a pair of rails 71, a beam 72, and a pair of squeegees 73. The rails 71 are arranged on the top surfaces of the entrance frame 11 and the exit frame 12, respectively, and extend in the Y-axis direction. The beam 72 is mounted so as to straddle a pair of rails 71, and moves on the rails 71 in the Y-axis direction by a drive mechanism (not shown). The pair of squeegees 73 are members for expanding the solder paste on the mask sheet 61. At the time of the printing process, while the beam 72 is reciprocated in the Y-axis direction, the pair of squeegees 73 are alternately slid along the surface of the mask sheet 61 in the forward and backward directions, so that the solder paste Is expanded.

[Details of Substrate Holding Mechanism of First Embodiment]
Subsequently, the backup unit 40 and the clamp unit 50 (substrate clamping device) that constitute the substrate holding mechanism according to the first embodiment will be described with reference to FIGS. The backup unit 40 includes a support plate 41, a number of backup pins 42, and a backup elevating unit 43.

  The support plate 41 is a flat plate having a size corresponding to the size of the substrate P, and can be moved up and down in a vertical direction (Z-axis direction) below the substrate P. The backup pin 42 is a pin implanted on the upper surface of the support plate 41 in the vertical direction. The height of the upper end of each backup pin 42 is the same, and these upper ends are in contact with the lower surface of the substrate P and lift the substrate P. The backup elevating unit 43 includes, for example, a ball screw mechanism and is installed on the support table 28. By driving the backup elevating unit 43, the support plate 41 and the backup pins 42 move up and down with respect to the support table 28.

  The clamp unit 50 includes a pair of clamp pieces, that is, a fixed clamp piece 51 and a movable clamp piece 52, and a clamp drive unit 53 that moves the movable clamp piece 52 in the Y-axis direction. The pair of clamp pieces 51 and 52 clamp and fix a pair of opposing sides of the substrate P. In the present embodiment, one of the pair of clamp pieces is a fixed clamp piece 51 that is immovable, and the other is a movable clamp piece 52 that is movable. In another embodiment, both of the pair of clamp pieces may be movable clamp pieces. The fixed clamp piece 51 and the movable clamp piece 52 are arranged at the same height above the main conveyor 31. 4 to 7, the fixed clamp piece 51 and the movable clamp piece 52, and the main conveyor 31 are supported on a support table 28 that can move in the XYZ axis directions and can rotate in the R axis. Have been.

  The rectangular substrate P has a first side PA and a second side PB, which are a pair of sides extending linearly in the X-axis direction. The fixed clamp piece 51 includes a holding surface 511 facing the first side PA. The holding surface 511 is a linear surface extending in the X-axis direction, and comes into surface contact with the first side PA when the substrate P is clamped. The moving clamp piece 52 includes a holding surface 521 facing the second side PB. The holding surface 521 is also a linear surface extending in the X-axis direction, and comes into surface contact with the second side PB when the substrate P is clamped.

  The clamp driving section 53 drives the movable clamp piece 52 to move in the direction of clamping the substrate P and the direction of releasing the clamp. The clamp driving section 53 includes an air cylinder 54, a connecting piece 55 and a moving piece 56. The air cylinder 54 is a driving source for moving the moving clamp piece 52. The connecting piece 55 is a member that is integrally attached to the lower surface of the movable clamp piece 52 and is movable on a guide member extending in the Y-axis direction. The moving piece 56 is a member that is attached to a drive shaft of the air cylinder 54 and moves in the Y-axis direction by the advance and retreat of the drive shaft. The upper part of the moving piece 56 is fixed to the connecting piece 55. As the moving piece 56 moves forward and backward in the Y-axis direction, the moving clamp piece 52 moves forward and backward along with the connecting piece 55 in the Y-axis direction.

  The clamp driving section 53 moves the movable clamp piece 52 between the clamp position and the release position. The clamp position is a position where the substrate P is clamped by the pair of clamp pieces 51 and 52 with a predetermined clamping force by moving the movable clamp piece 52 in the Y-axis direction. The release position is a position where the clamp of the substrate P is released by moving the movable clamp piece 52 backward in the Y-axis direction by a predetermined distance from the clamp position.

  The operation of the backup unit 40 and the clamp unit 50 will be described. FIG. 4 shows a state where the substrate P is being conveyed by the main conveyor 31 or a state where the conveyance is completed. The lower surface near the first side PA and the second side PB of the substrate P is supported by the belt conveyor 32, respectively. The support plate 41 of the backup unit 40 is in a lowered state, and the upper end of the backup pin 42 is separated from the lower surface of the substrate P. The moving clamp piece 52 is at the release position described above and does not restrain the substrate P. In this state, when the belt conveyor 32 is driven, the substrate P is sent in the X-axis direction. The backup unit 40 and the clamp unit 50 are in the state shown in FIG. 4 when the substrate P is loaded into the printing stage ST, when loading is completed, and when the substrate P is unloaded to the printing stage ST.

  FIG. 5 shows a state where the substrate P is lifted by the backup unit 40. When the substrate P to be subjected to the printing process is carried into the printing stage ST by the main conveyor 31, the backup elevating unit 43 performs the lifting operation of the support plate 41, and the upper end of the backup pin 42 contacts the lower surface of the substrate P. Let it. By continuing the lifting operation, the backup pins 42 support the substrate P instead of the belt conveyor 32. The backup elevating unit 43 executes the lifting operation until the substrate P is substantially flush with the vicinity of the upper ends of the fixed clamp piece 51 and the movable clamp piece 52. If the substrate P has a downwardly convex warp, the above-described warp correcting operation is performed by the correcting mechanism 33 in the state of FIG.

  FIG. 6 shows a state in which the clamp unit 50 clamps and fixes the substrate P while the backup unit 40 supports the substrate P. That is, the movable clamp piece 52 is moved to the clamp position by the clamp driving unit 53, and the clamping surface 521 of the movable clamp piece 52 is in the second side PB, and the clamping surface 511 of the fixed clamp piece 51 is in the first side PA. The pair of clamp pieces 51 and 52 are in contact with each other and hold the substrate P with a predetermined clamping force. When the air cylinder 54 pulls the moving piece 56, first, the holding surface 521 of the moving clamp piece 52 presses the second side PB of the substrate P. When the traction is further continued, the substrate P is horizontally moved leftward in FIG. 6, and the first side PA eventually comes into contact with the holding surface 511 of the fixed clamp piece 51. Thus, the substrate P is in a clamped state.

  FIG. 6 shows the state of the backup unit 40 and the clamp unit 50 when the printing process is performed on the substrate P. That is, the four-axis unit 20 is driven in a state where the lower surface and the side surface of the substrate P are restrained by the backup unit 40 and the clamp unit 50 as shown in FIG. The support table 28 is moved such that are superimposed. Here, the clamping force of the substrate P by the pair of clamp pieces 51 and 52 does not merely clamp the substrate P, but also the X-axis, Y-axis, and Z-axis of the support table 2 by the four-axis unit 20 for the superposition. It is necessary to set a clamping force that does not cause a displacement in the fixed state of the substrate P due to the moving force in the axial and R-axis directions. When the alignment of the substrate P with respect to the mask sheet 61 is completed, the squeegee unit 70 executes a solder paste printing process. During the printing process, the lower surface of the substrate P is supported by the backup pins 42 and the first and second side edges PA and PB are fixed by the pair of clamp pieces 51 and 52, so that the substrate P does not shift. .

  FIG. 7 shows a state in which the clamping of the substrate P by the clamp unit 50 is released, and the support of the substrate P shifts from the backup unit 40 to the main conveyor 31. The clamp driving section 53 moves the movable clamp piece 52 to the release position, and the holding surface 521 is separated from the second side PB. The backup elevating unit 43 performs an operation of lowering the support plate 41. As a result, when the substrate P is lowered and lowered to the level of the belt conveyor 32, the substrate P is supported by the belt conveyor 32.

  The state in FIG. 7 is a state when the printing process on the substrate P is completed and the processed substrate P is carried out of the printing stage ST. In unloading, the backup pin 42 is lowered from the state shown in FIG. 7 to the state shown in FIG. Thereafter, the belt conveyor 32 and the downstream conveyor 16 are driven, and the substrate P is carried out.

[Electrical Configuration of Screen Printing Apparatus]
FIG. 8 is a block diagram illustrating an electrical configuration of the screen printing device 1. The screen printing apparatus 1 includes an imaging unit 81, a sensor 82, a shaft driving unit 83, a substrate transport motor 84, a squeegee driving unit 85, and a control unit 90, in addition to the above-described backup elevating unit 43 and clamp driving unit 53. .

  The imaging unit 81 is a unit that acquires a required image for, for example, position recognition or shape recognition in the screen printing device 1. For example, an image of a fiducial mark provided on the substrate P is taken, and the position of the substrate P on the printing stage ST can be recognized. The sensor 82 acquires information necessary for controlling the screen printing apparatus 1, such as an environment sensor such as a temperature sensor, a position sensor, and a pressure sensor. In the present embodiment, it is desirable to include a measuring unit (for example, a laser displacement meter) for detecting the warpage of the substrate P as one of the sensors 82.

  The axis driving unit 83 includes an X-axis servo motor 831, a Y-axis servo motor 832, a Z-axis servo motor 833, and an R-axis servo motor 834. As described above, the X-axis servo motor 831 is a drive source for moving the X-axis table 24 in the X-axis direction, the Y-axis servo motor 832 is a drive source for moving the Y-axis table 22 in the X-axis direction, and a Z-axis servo motor. A drive source 833 moves the support table 28 in the Z-axis direction, and an R-axis servo motor 834 drives the R-axis table 26 around the Z-axis.

  The substrate transport motor 84 is a drive source for driving the upstream conveyor 15, the downstream conveyor 16, and the belt conveyor 32 provided in the main conveyor 31. The squeegee drive unit 85 is a drive mechanism for driving the beam 72 of the squeegee unit 70 to move in the Y-axis direction and for moving the pair of squeegees 73 up and down.

  The control unit 90 is composed of a microcomputer or the like, and controls the operation of the screen printing apparatus 1 overall. The control unit 90 functions as an imaging control unit 91, an image processing unit 92, an arithmetic processing unit 93, a clamp control unit 94, an axis control unit 95, a storage unit 96, and a transport control unit by executing a predetermined program. The operation is performed so as to include a lifting / lowering control unit 97 and a squeegee control unit 99.

  The imaging control unit 91 controls the movement and the imaging operation of the imaging unit 81. For example, when imaging a fiducial mark on the substrate P, the imaging control unit 91 controls the imaging unit 81 to move to a position for photographing the mark and to image the mark. The image processing unit 92 performs image processing such as edge detection processing for shape recognition on the image data acquired by the imaging unit 81. The arithmetic processing unit 93 performs various arithmetic processes necessary for controlling the screen printing device 1. The arithmetic processing unit 93 further performs arithmetic processing for situation recognition and control condition change based on the information of each part obtained by the sensor 82.

  The clamp control section 94 controls the movement of the movable clamp piece 52 by controlling the clamp drive section 53. At this time, the clamp control unit 94 refers to a parameter (parameter relating to the clamping force of the substrate) indicating the clamping force of the substrate P to be clamped by the pair of clamping pieces 51 and 52. Specifically, the clamp control unit 94 controls a regulator attached to the air cylinder 54, and controls the thrust of the air cylinder 54 according to the parameter. This thrust determines the clamping force with which the pair of clamp pieces 51 and 52 clamp the substrate P. The storage unit 96 stores the parameters set for each of the plurality of types of substrates P to be clamped in association with the identification numbers of the substrates.

  The axis control unit 95 controls the operation of the four-axis unit 20 that moves the support table 28 in the XYZR axis directions by controlling the axis driving unit 83, and controls the operation of positioning the substrate P on the mask sheet 61 and the like. . Note that the axis control unit 95 causes the support table 28 to move in the axial direction while the substrate P is exclusively clamped by the pair of clamp pieces 51 and 52.

  The transfer control unit 97 controls the board transfer motor 84 to control the board transfer operation of the board P by the belt conveyor 32. The elevating control unit 98 controls the backup elevating unit 43 to control the elevating operation of the substrate P by the backup unit 40. The squeegee control unit 99 controls the squeegee driving unit 85 to control the print processing operation by the squeegee 73.

[Setting of clamping force]
As described above, various problems occur if the clamping force of the substrate P by the pair of clamp pieces 51 and 52 is not properly set. If the clamping force is too strong, the clamped substrate P may be warped or the substrate P may be damaged such as cracking. On the other hand, if the clamping force is too weak, the position of the clamped substrate P may be shifted or the substrate P may fall. These positional deviations and drops become remarkable when the support table 28 is moved by the four-axis unit 20 in a state where the substrate P is clamped. In the present embodiment, the clamping force is set appropriately so as not to cause the above-described inconvenience, and is stored in the storage unit 96 in advance.

FIG. 9 is a schematic diagram for explaining an edge clamping force on the substrate P, and FIG. 10 is a diagram schematically showing a moving force acting on the clamped substrate P. The rectangular substrate P has a side (a first side PA and a second side PB) having a length L along the X-axis direction, a side having a width W along the Y-axis direction, and a side surface having a width W along the Y-axis direction. And a thickness T. The pair of clamp pieces 51 and 52 clamp the side face PE having the length L and the thickness T. The cross-sectional area C of the side PE is
C = L × T
It is. The moving clamp piece 52 given a thrust by the air cylinder 54 applies pressure to the side surface PE, and clamps the substrate P together with the fixed clamp piece 51. The pressure applied to the side surface PE during such clamping is the clamping force F.

Assuming that the clamping force F is received on the entire surface of the side surface PE, the compressive stress S applied to the substrate P is
S = F / C
It is represented by The clamping force F is selected so that the compressive stress S applied to the substrate P to be clamped when the substrate P is clamped is appropriate. A is a stress at which buckling deformation occurs in the substrate P due to the compressive stress S, that is, a first stress at which the substrate P starts to be warped. The relationship between the first stress A and the compressive stress S is a relational expression depending on the width W, the thickness T, and the Young's modulus of the substrate P. When A> S, the substrate P is not warped. When A <S, the substrate P is warped.

  As schematically shown in FIG. 10, when the substrate P is clamped by the pair of clamp pieces 51 and 52, the support table 28 supporting the pair of clamp pieces 51 and 52 moves in the XYZ-axis directions, It receives a moving force that rotates around its axis (R axis). A second stress at which a displacement starts to occur in the fixed state of the substrate P by the pair of clamp pieces 51 and 52 due to the moving force is defined as B. The relationship between the second stress B and the compressive stress S is a relational expression that depends on the cross-sectional area C of the side surface PE, the weight of the substrate P, and the axial acceleration in the XYZR axis direction. Is displaced in the fixed state, and does not occur when B <S.

From the above, the compressive stress S (clamping force F)
B <S <A (1)
Is selected so that the following relationship is satisfied, when the substrate P is clamped by the pair of clamp pieces 51 and 52, the substrate P does not warp or crack, and the substrate P is prevented from being displaced or dropped. can do. The clamp force F is applied to the arithmetic processing unit 93 by applying data such as the length L, width W, thickness T, and Young's modulus of the substrate to be clamped in a predetermined relational expression. And the value of the second stress B can be calculated and set by a method of determining an appropriate compressive stress S (clamping force F) in the range of B to A. These values are stored in the storage unit 96 as parameters relating to the clamping force of the substrate. Alternatively, a table indicating the relationship between each of the substrates P and the compressive stress S (clamping force F) may be created in advance, and the table may be stored in the storage unit 96. The clamp control unit 94 controls the clamp driving unit 53 using these parameters.

  Specific examples of the values of the first stress A and the second stress B will be described. FIG. 11 is a graph showing an example of the relationship between the clamping force F (edge clamping force) on the side surface PE of the substrate P and the limit value of the warpage due to the thickness of the substrate P. L1 in the figure indicates the minimum setting value of the clamping force F in the screen printing apparatus 1, and F2 indicates the maximum setting value. FIG. 11 shows that, for example, when the substrate has a thickness T = 1.0 mm, the clamping force at which the substrate P is warped by the clamp is 34N. The length L of the substrate P is 180 mm and the width W is 180 mm, and the Young's modulus is about 20 GPa.

  FIG. 12 is a graph showing an example of a force applied to the substrate P by the table axis acceleration. A straight line Q1 indicates a force applied to the substrate P when the substrate P (the support table 28) clamped at an axial acceleration of 100% of the set value is moved. FIG. 12 shows that, for example, when a substrate P weighing 600 g is moved in the XYZR axis direction at an axial acceleration of 100%, a moving force of 5.9 N acts on the substrate P. In this case, if the clamping force of the substrate P is 5.9 N or less, there is a high possibility that fixing displacement will occur. A straight line Q2 indicates a force applied to the substrate P when the axial acceleration is set to 80% of the set value. The straight lines Q3, Q4, and Q5 show the cases where the axial acceleration is 60%, 40%, and 20% of the set value, respectively.

  According to the examples of FIGS. 11 and 12, in the case of a substrate P having a thickness T = 1.0 mm and a weight of 600 g, the limit value at which the substrate P warps, that is, the first stress A is 34N from FIG. It is. Further, from FIG. 12, the moving force acting on the substrate P at 100% axial acceleration, that is, the second stress B is 5.9N. Therefore, if the clamping force F is set so that the compressive stress S falls within the range of 5.9N to 34N, the substrate P is not warped or fixedly displaced when the substrate P is clamped.

[When the relationship of B <A cannot be satisfied]
Depending on the material and thickness of the substrate P, if the axial acceleration (axial moving force) is 100% axial acceleration (first moving force) as set, the relationship of B <A may not be established. It can happen. For example, when the substrate P is a relatively brittle substrate such as a ceramic substrate, the substrate P may be broken before warping occurs. When the substrate P is considerably thin, the second stress B at which the fixing displacement occurs may be larger than the first stress A at which the substrate P buckles. That is, if the clamping force F that satisfies the second stress B necessary for moving the substrate P in the clamped state at the normal speed (100% axial acceleration) is set, the substrate P may be warped or cracked. is there.

  As described above, when the axial acceleration is set to 100%, if the relationship of B <A is not established for the substrate P to be clamped, the axis control unit 95 controls the four-axis unit 20 to change the axial acceleration. I do. Specifically, the axis control unit 95 moves the support table 28 so that the axis acceleration is smaller than the axis acceleration of 100% and the support table 28 is moved with the axis acceleration (second moving force) that satisfies the relationship of B <A. The drive unit 83 is controlled.

  Referring to FIGS. 11 and 12, for example, in the case of a substrate P having a thickness T = 0.6 mm and a weight of 600 g, the first stress A at which warpage of the substrate P occurs is 3.4 N from FIG. 11. . Also, from FIG. 12, the moving force (second stress B) acting on the substrate P at 100% axial acceleration is 5.9N. In this case, B> A, and the above equation (1) cannot be satisfied. However, when the axial acceleration is reduced to about 60% or less, the relationship of B <A can be established. As described above, when the relationship of B <A is not established, the axis control unit 95 sets the axial acceleration or the moving speed to be smaller than usual and sets the moving force in the axial direction to be smaller, thereby changing the relationship of B <A. Create. Thereby, even if the substrate P has a special material and thickness, it is possible to clamp the substrate P without warpage and fixed displacement.

[When the substrate has a shape characteristic]
For example, when the substrate P is originally warped, or when the substrate P has a relatively large notch or slit, the substrate P is not a simple rectangular substrate but warps. If the substrate P has an easily-shaped characteristic, the occurrence state of the warp of the substrate P when the clamping force F is applied changes. When such a shape characteristic is known, the clamp driving unit 53 modifies the value of the first stress A according to the shape characteristic, applies the above-described equation (1), and resets the parameter. Perform processing.

  FIG. 13A is a schematic diagram showing a clamped state of a substrate (upwardly warped substrate Pu) having an upwardly curved warp, and FIG. 13B is a downwardly convexly curved warp. It is a schematic diagram which shows the clamp situation of the board | substrate (curved board Pd) which has (). As described above, in the substrates Pu and Pd in which warpage has already occurred before being clamped by the pair of clamp pieces 51 and 52, the first stress A in which the warp is large at the time of clamping is the same as that in which no warp occurs. It is smaller than the substrate. Therefore, it is necessary to correct the value of A in the equation (1) to a value Ax (Ax = A-x) reduced by a predetermined value x. The value x is a value that increases as the amount of warpage increases.

  However, in the case of the downwardly warped substrate Pd in FIG. 13B, since the backup pin 42 exists below the substrate, it is not necessary to correct the first stress A to Ax. As described above, the substrate P is lifted by the backup pins 42 and then clamped by the pair of clamp pieces 51 and 52. The correcting mechanism 33 also performs a warp correcting operation. Accordingly, in the case of the downwardly warped substrate Pd, since the support by the backup pin 42 can be expected at the time of clamping, the decrease in the first stress A does not need to be considered.

As described above, in the case of the warped substrate Pu, the clamp drive unit 53 resets the clamping force F by applying the following equation (1) ′.
B <S <(A−x) (1) ′
If it is not necessary to change the clamping force F as a result, no resetting is performed. On the other hand, in the case of the warped substrate Pd, the clamp driving unit 53 sets the clamping force F by applying the above equation (1) as it is.

  FIG. 14 (A) shows a substrate P1 having a notch PC as one of various geometrical features of the substrate, and FIG. 14 (B) shows a substrate P1 having various geometrical features of the substrate. Is an example of the substrate P2 provided with the slit PD. In the substrate P1, the notch PC that enters inside from the rectangular periphery becomes a weak point of mechanical strength. In the substrate P2, the slit PD perforated inside the rectangular periphery becomes a weak point of mechanical strength. Therefore, in the substrates P1 and P2, the first stress A at which warpage occurs at the time of clamping is smaller than that of a substrate having no notch PC or slit PD. Even in such a case, the clamp driving unit 53 sets the value Ax (Ax = Ax) in which the value of A in Expression (1) is reduced by a predetermined value x in accordance with the size and shape of the notch PC or the slit PD. -X). Accordingly, even when the substrate P has various geometrical characteristics, the substrate P can be appropriately clamped.

[Second embodiment]
In the second embodiment, a pair of clamp pieces 51 and 52 are used to actually clamp an unknown substrate P whose parameters are not stored in the storage unit 96 with an arbitrary clamping force F, and the four-axis unit 20 performs the clamping. An example in which the support table 28 is moved to detect the first stress A and the second stress B for an unknown substrate P will be described.

  FIG. 15 is a schematic diagram of a clamp unit 50A according to the second embodiment. The clamp unit 50A has a board photographing camera 811 (position measuring means) and a laser displacement meter 821 (measuring means) in addition to the fixed clamp piece 51 and the moving clamp piece 52. The board photographing camera 811 is a camera that can capture a fiducial mark FM (mark for positioning) attached to the board P, as shown in FIG. The laser displacement meter 821 includes a light source that emits a laser beam L and a light receiving element that receives a reflected beam of the laser beam L, and calculates the amount of warpage of the substrate based on the amount of reflected light when the laser beam L is irradiated along the substrate. It is a sensor to detect. In the block diagram of FIG. 8, the board photographing camera 811 is a part of the imaging unit 81, and the laser displacement meter 821 is a part of the sensor 82. The board photographing camera 811 is mounted on the support table 28 so that the relative position with respect to the clamp unit 50 does not change.

  When the screen printing apparatus 1 sets, for example, a group of unknown substrates P whose parameters are not stored in the storage unit 96 as a print processing target, the control unit 90 sets a substrate to be printed first as a test substrate Pt, or A test substrate Pt identical to the unknown substrate P is separately prepared, and a process of detecting the first stress A and the second stress B is executed. The control unit 90 carries the test substrate Pt into the printing stage ST, supports the test substrate Pt with the backup unit 40, and actually clamps the test substrate Pt with the clamp unit 50 in the procedure described above with reference to FIGS.

  At this time, while changing the clamping force F of the test substrate Pt by the pair of clamp pieces 51 and 52, the amount of warpage generated in the test substrate Pt by this clamp is monitored. That is, while operating the laser displacement meter 821 to irradiate the test substrate Pt with the laser light L, the clamp control unit 94 controls the clamp drive unit 53 to reduce the thrust (clamp force F) of the movable clamp piece 52. Change in a predetermined range. When the test substrate Pt is warped and the warped portion interrupts the optical path of the laser beam L, reflected light is incident on the laser displacement meter 821. A dummy mirror may be mounted near the center of the test substrate Pt so that the reflected light returns to the laser displacement meter 821 easily. The arithmetic processing unit 93 analyzes the measurement data obtained from the laser displacement meter 821 and derives the relationship between the clamping force F and the amount of warpage. Thereby, the first stress A on the test substrate Pt can be detected. As a measuring means instead of the laser displacement meter 821, a camera for imaging the test substrate Pt may be provided, and the warp displacement of the test substrate Pt may be monitored by an image processing technique.

  Subsequently, the axis control unit 95 controls the axis driving unit 83 to move the support table 28 that supports the pair of clamp pieces 51 and 52 that clamp the test board Pt in one or more of the XYZR axis directions. Control. At this time, the axis control unit 95 may change the axis acceleration from 100% axis acceleration to a slower axis acceleration. Further, the clamping force F may be the first stress A detected earlier, or may be a different clamping force F.

  Further, the imaging control unit 91 causes the board photographing camera 811 to image the fiducial mark FM of the test board Pt, and monitors the amount of displacement of the test board Pt in the fixed state during the movement in the axial direction. Specifically, the image processing unit 92 recognizes the position of the fiducial mark FM based on the acquired image, and detects the swing of the mark FM. In FIG. 16, a state in which the test board Pt is clamped at the regular fixed position by the pair of clamp pieces 51 and 52 is indicated by a solid line P3, and a state in which the fixed state of the test board Pt is shifted is indicated by a dotted line P4. I have.

  If the test substrate Pt is stably clamped at the position P3 during the movement of the support table 28, the position of the fiducial mark FM in the image acquired by the substrate photographing camera 811 does not move. On the other hand, when the fixed state of the test substrate Pt shifts, that is, when the position of the test substrate Pt changes from P3 to P4, the position of the fiducial mark FM also changes according to the change in position. This makes it possible to detect the second stress B on the test substrate Pt.

  The clamp control unit 94 derives an appropriate clamping force F by applying the values of the first stress A and the second stress B for the test board Pt obtained as described above to the above equation (1). . The obtained clamping force F is stored in the storage unit 96. In the subsequent clamping of the unknown substrate P, the clamp control unit 94 reads the clamping force F from the storage unit 96 and executes the clamping operation. Accordingly, the first stress A and the second stress B can be set according to the actual state of the substrate P, so that the substrate P is prevented from warping or cracking, being displaced or dropped during clamping. be able to.

  According to the screen printing apparatus 1 to which the substrate clamping device according to the present invention described above is applied, not only the first stress A at which the substrate P starts to be warped but also the support table 28 in a state where the substrate P is clamped. The clamp force F of the substrate P by the pair of clamp pieces 51 and 52 is set in consideration of the second stress B at which the displacement of the fixed state of the substrate P when the substrate P is moved is considered. Therefore, not only does the clamp P cause warping or cracking of the substrate P, but also when the four-axis unit 20 moves the pair of clamp pieces 51 and 52 together with the support table 28, it is possible to prevent the substrate P from being fixed or shifted. it can.

[Description of Modified Embodiment]
The present invention is not limited to the above embodiment. For example, in the above embodiment, an example in which the substrate clamping device of the present invention is applied to the screen printing device 1 has been described. The substrate clamping device can be applied to other substrate processing devices. For example, a substrate mounting apparatus having a mounting head (processing section) for mounting electronic components on a substrate, and a coating apparatus having a dispenser head (processing section) for applying an adhesive or cream solder to a substrate. And the like.

FM fiducial mark (mark for positioning)
P board PA, PB 1st side, 2nd side (a pair of sides)
PC Notch PD Slit 1 Screen printing device (substrate processing device)
20 4-axis unit (axis drive unit)
28 Supporting Table (Table)
31 Main conveyor 32 Belt conveyor 40 Backup unit 50 Clamp unit (substrate clamp device)
Reference Signs List 51 fixed clamp piece 52 moving clamp piece 53 clamp drive unit 60 mask holding unit 70 squeegee unit 811 board photographing camera (position measuring means)
821 Laser displacement meter (measuring means)
83 axis drive unit 90 control unit 94 clamp control unit (control unit)
95 Axis control unit (control unit)
96 storage unit

Claims (6)

A pair of clamp pieces that clamp and fix a pair of opposing sides of the rectangular substrate,
A table that supports the pair of clamp pieces and is movable in a predetermined axial direction,
A clamp driving unit that drives at least one of the pair of clamp pieces in a direction to clamp the substrate and a direction to release the clamp;
An axis driving unit that moves the table in the axial direction;
A storage unit that stores a parameter related to a clamping force of the substrate by the pair of clamp pieces in association with a substrate to be clamped,
Controlling the clamp drive unit with reference to the parameter, and a control unit that controls the operation of the axis drive unit,
The control unit performs control to move the table in the axial direction in a state where the substrate is clamped by the pair of clamp pieces,
The parameter is a compressive stress applied to the substrate at the time of clamping of the substrate, S, a first stress at which the substrate starts to be warped by the compressive stress, A, and in a state where the substrate is clamped by the pair of clamp pieces. When the table is moved in the axial direction, when the second stress at which the displacement of the fixed state of the substrate by the pair of clamp pieces starts to occur due to the moving force due to the movement is B,
B <S <A (1)
Is set so as to satisfy the relation, in the substrate clamping apparatus,
When the moving force in the axial direction is set to a predetermined first moving force, when the relationship of B <A is not established for the substrate to be clamped,
The control unit controls the shaft drive unit to move the table with a second moving force that makes the axial moving force smaller than the first moving force and that satisfies the relationship of B <A. A substrate clamping device. A pair of clamp pieces that clamp and fix a pair of opposing sides of the rectangular substrate,
A table that supports the pair of clamp pieces and is movable in a predetermined axial direction,
A clamp driving unit that drives at least one of the pair of clamp pieces in a direction to clamp the substrate and a direction to release the clamp;
An axis driving unit that moves the table in the axial direction;
A storage unit that stores a parameter related to a clamping force of the substrate by the pair of clamp pieces in association with a substrate to be clamped,
Controlling the clamp drive unit with reference to the parameter, and a control unit that controls the operation of the axis drive unit,
The control unit performs control to move the table in the axial direction in a state where the substrate is clamped by the pair of clamp pieces,
The parameter is a compressive stress applied to the substrate at the time of clamping of the substrate, S, a first stress at which the substrate starts to be warped by the compressive stress, A, and in a state where the substrate is clamped by the pair of clamp pieces. When the table is moved in the axial direction, when the second stress at which the displacement of the fixed state of the substrate by the pair of clamp pieces starts to occur due to the moving force due to the movement is B,
B <S <A (1)
In the substrate clamping device set to satisfy the relationship of
For the substrate to be clamped, if a shape characteristic that varies the occurrence of the warpage is added,
The substrate clamping device, wherein the control unit corrects the value of A in accordance with the shape characteristic, applies the expression (1), and resets the parameter. The substrate clamping device according to claim 2 ,
A substrate clamping apparatus, wherein the topographical features include the amount and direction of warping of the substrate before being clamped by the pair of clamp pieces, and the amount of notch or slit in the substrate. A pair of clamp pieces that clamp and fix a pair of opposing sides of the rectangular substrate,
A table that supports the pair of clamp pieces and is movable in a predetermined axial direction,
A clamp driving unit that drives at least one of the pair of clamp pieces in a direction to clamp the substrate and a direction to release the clamp;
An axis driving unit that moves the table in the axial direction;
A storage unit that stores a parameter related to a clamping force of the substrate by the pair of clamp pieces in association with a substrate to be clamped,
Controlling the clamp drive unit with reference to the parameter, and a control unit that controls the operation of the axis drive unit,
The control unit performs control to move the table in the axial direction in a state where the substrate is clamped by the pair of clamp pieces,
The parameter is a compressive stress applied to the substrate at the time of clamping of the substrate, S, a first stress at which the substrate starts to be warped by the compressive stress, A, and in a state where the substrate is clamped by the pair of clamp pieces. When the table is moved in the axial direction, when the second stress at which the displacement of the fixed state of the substrate by the pair of clamp pieces starts to occur due to the moving force due to the movement is B,
B <S <A (1)
In the substrate clamping device set to satisfy the relationship of
Measuring means for detecting the amount of warpage of the substrate is further provided,
The control unit includes:
For the unknown substrate whose parameters are not stored in the storage unit, the pair of clamp pieces are used to actually perform the clamping, and the measuring unit monitors the amount of warpage generated in the unknown substrate by the clamp,
From the results of the monitor, find the value of A for the unknown substrate,
A substrate clamping device for storing a parameter set by applying the expression (1) with the obtained value of A in the storage unit. A pair of clamp pieces that clamp and fix a pair of opposing sides of the rectangular substrate,
A table that supports the pair of clamp pieces and is movable in a predetermined axial direction,
A clamp driving unit that drives at least one of the pair of clamp pieces in a direction to clamp the substrate and a direction to release the clamp;
An axis driving unit that moves the table in the axial direction;
A storage unit that stores a parameter related to a clamping force of the substrate by the pair of clamp pieces in association with a substrate to be clamped,
Controlling the clamp drive unit with reference to the parameter, and a control unit that controls the operation of the axis drive unit,
The control unit performs control to move the table in the axial direction in a state where the substrate is clamped by the pair of clamp pieces,
The parameter is a compressive stress applied to the substrate at the time of clamping of the substrate, S, a first stress at which the substrate starts to be warped by the compressive stress, A, and in a state where the substrate is clamped by the pair of clamp pieces. When the table is moved in the axial direction, when the second stress at which the displacement of the fixed state of the substrate by the pair of clamp pieces starts to occur due to the moving force due to the movement is B,
B <S <A (1)
In the substrate clamping device set to satisfy the relationship of
The substrate further includes a positioning mark, and further includes a position measurement unit capable of determining a deviation from a reference position of the substrate by imaging the mark,
The control unit includes:
For an unknown substrate whose parameters are not stored in the storage unit, while the substrate is clamped by the pair of clamp pieces, the table is moved in the axial direction, and the unknown substrate is Monitor the amount of displacement of the fixed state when moving in the axial direction of the,
From the results of the monitor, find the value of B for the unknown substrate,
A substrate clamping device for storing a parameter set by applying the expression (1) with the obtained value of B in the storage unit. A processing unit for performing predetermined processing on the substrate,
The substrate clamping device according to any one of claims 1 to 5 , which clamps the substrate,
A substrate processing apparatus comprising: