Gantry apparatus and component mounting apparatus

Abstract

To accurately move a working head to a moving target position in a gantry device adopting double support single drive.SOLUTION: A substrate recognition camera 9 picks up an image of a plate jig TP having a plurality of marks MA while a Y-axis linear motor 15 sequentially performs first movement for moving a beam 14 to a positive direction Y2 in a Y direction and second movement for moving the beam 14 to a negative direction Y1. Errors between the positions of the marks MA specified on the basis of the image and the theoretical positions of the marks MA are obtained, and first correction values for correcting the errors (d2) in the first movement and second correction values for correcting the errors (d1) in the second movement are obtained. In the component mounting work by the head unit 6, when the beam 14 is moved to the Y2 in the positive direction, the movement target position is set using the first corrected value, and when the beam 14 is moved to the Y1 in the negative direction, the movement target position is set using the second corrected value.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a gantry device having a working head, and a component mounting apparatus equipped with the gantry device. [Background technology]

[0002] A gantry device having a work head that performs a predetermined operation on a workpiece is known. The gantry device includes a pair of parallel Y-direction rails, a gate-shaped beam that extends in the X direction and is movably supported on the pair of Y-direction rails, and a motor that moves the beam along the pair of Y-rails. The work head is mounted on the beam so as to be movable in the X direction. Such a gantry device is used, for example, in a component mounting device that mounts components on a circuit board.

[0003] In order for the work head to perform work with high positional accuracy, it is necessary to correct movement errors that occur due to various factors and move the work head in the XY directions toward the target movement position. Patent Document 1 discloses a technique for correcting the XY movement of the work head of a component mounting device. In this correction technique, a plate having a fiducial mark is imaged with a camera mounted on the work head, and the XY movement correction amount of the work head is calculated based on the error between the theoretical position of the fiducial mark and the position of the mark on the image. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-244696 Summary of the Invention [Problem to be solved by the invention]

[0005] The correction technology in Patent Document 1 applies a uniform correction value regardless of the operating conditions of the X and Y axes, which can make it difficult to accurately correct movement errors. In particular, problems become apparent when a structure is adopted in which the beam drive motor is located on only one side of a pair of Y rails (referred to as "double-support single drive" in this specification) due to the need to simplify and save space in the beam drive system. In other words, with double-support single drive, the work head may not be able to accurately move to the target position with a uniform correction value due to the effects of factors such as the rigidity of the beam and the frictional resistance between the beam and the Y rail on the non-drive side.

[0006] An object of the present invention is to accurately move a working head to a target position in a gantry device employing a double support single drive. [Means for solving the problem]

[0007] A gantry apparatus according to one aspect of the present invention includes a beam including a first end and a second end and extending in a first direction; a work head movably mounted in the first direction relative to the beam and performing a predetermined operation on a workpiece placed in a preset working area; a camera mounted on the work head and capable of capturing an image of the working area; a linear guide extending in a second direction perpendicular to the first direction and including a first guide movably supporting the first end of the beam and a second guide movably supporting the second end; a motor that applies a driving force to the first end of the beam to move the beam in the second direction; and a control unit that controls the camera and the motor, wherein the control unit controls the camera and the motor before the working head performs the predetermined operation. The motor is caused to sequentially perform a first movement that moves the beam in the positive direction of the second direction and a second movement that moves the beam in the negative direction opposite to the positive direction, while the camera is caused to capture an image of a plate jig having a plurality of marks arranged in the working area, and the error between the position of the mark identified based on the image and the theoretical position of the mark is determined, and a first correction value that corrects the error in the first movement and a second correction value that corrects the error in the second movement are determined, and during the specified work by the working head, a movement target position is set using the first correction value when the beam is moved in the positive direction of the second direction, and a movement target position is set using the second correction value when the beam is moved in the negative direction.

[0008] According to this aspect, the gantry device is a double-support single-drive device in which a motor applies driving force only to the first end of the beam, thereby simplifying the beam drive system and saving space. As correction values ​​for moving the beam, the beam is moved in two directions, positive and negative, of the second direction, and a first correction value and a second correction value are obtained for each movement direction. Since the target movement position is set using correction values ​​corresponding to each direction when moving the beam in the positive and negative directions, rather than a uniform correction value, the working head can be moved accurately to the required position.

[0009] In the above-mentioned gantry apparatus, it is desirable that the control unit calculates errors for each of the first movement and the second movement by varying the movement distance or acceleration / deceleration of the beam, and calculates the first correction value and the second correction value for each movement distance or acceleration / deceleration.

[0010] The beam movement error may differ not only depending on the difference between the positive and negative movement directions, but also on the beam movement distance and acceleration / deceleration. According to the above-described embodiment, the correction value is calculated for each movement distance or acceleration / deceleration, so that the movement of the work head can be corrected more accurately.

[0011] A gantry apparatus according to another aspect of the present invention includes a beam including a first end and a second end and extending in a first direction; a work head movably mounted in the first direction relative to the beam and performing a predetermined operation on a workpiece placed in a preset work area; a camera mounted on the work head and capable of capturing an image of the work area; a linear guide extending in a second direction perpendicular to the first direction and including a first guide movably supporting the first end of the beam and a second guide movably supporting the second end; a motor that applies a driving force to the first end of the beam to move the beam in the second direction; and a control unit for controlling the camera and the motor. and a control unit, wherein before the work head performs the specified work, the control unit causes the motor to sequentially move the beam in the second direction at different movement distances or acceleration / deceleration speeds while causing the camera to capture an image of a plate jig having a plurality of marks arranged in the work area, determines the error between the position of the mark identified based on the image and the theoretical position of the mark, and determines a correction value to correct the error for each of the different movement distances or acceleration / deceleration speeds, and sets a movement target position of the beam using the correction value according to the movement distance or acceleration / deceleration speed of the beam during the specified work by the work head.

[0012] According to this aspect, as a correction value for moving the beam, the beam is moved at different movement distances or acceleration / deceleration speeds, and a correction value for each movement distance or acceleration / deceleration speed is obtained. Since the movement target position is set using a correction value according to the movement distance or acceleration / deceleration speed of the beam, rather than a uniform correction value, the working head can be moved accurately to the required position.

[0013] In the above gantry apparatus, the workpiece may be a substrate on which an electronic component is to be mounted, and the working head may be a mounting head that mounts the electronic component on the substrate.

[0014] According to this aspect, the mounting head can be accurately moved to the target mounting position using the above correction value, and the electronic component can be mounted at a predetermined position on the board.

[0015] A component mounting apparatus according to yet another aspect of the present invention includes the above-described gantry device, a conveyor that transports the workpiece substrate into and out of the work area, and a component supply unit that supplies electronic components to be mounted on the substrate, wherein the work head is a mounting head that takes the electronic components from the component supply unit and mounts them on the substrate.

[0016] According to this aspect, it is possible to provide a component mounting device that can accurately move the mounting head to the target mounting position based on the correction value derived by the control unit of the gantry device, and mount electronic components at predetermined positions on the board. [Effects of the Invention]

[0017] According to the present invention, in a gantry device employing a double support single drive and a component mounting device using the gantry device, the working head or mounting head can be accurately moved to a target movement position. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a plan view showing a schematic configuration of a component mounting apparatus to which the gantry device of the present invention is applied. [Figure 2] FIG. 2 is a front view of the component mounting apparatus shown in FIG. [Figure 3] FIG. 3 is a block diagram showing the electrical configuration of the component mounting apparatus. [Figure 4] FIG. 4 is a flowchart showing an example of a process for acquiring a movement correction value of a head unit. [Figure 5] FIG. 5 is a plan view showing the configuration of a gantry device portion of the component mounting apparatus. [Figure 6] 6A and 6B are plan views showing how movement correction values ​​in the positive and negative directions of the beam are obtained according to the first embodiment of the present invention. [Figure 7] 7A and 7B are graphs showing the correction values ​​obtained by the operation of FIG. [Figure 8] FIG. 8 is a flowchart showing an example of movement control of the head unit during component mounting. [Figure 9] 9(A) and 9(B) are plan views showing how movement correction values ​​for different beam movement distances are obtained according to the second embodiment of the present invention. [Figure 10] 10A and 10B are graphs showing correction values ​​for each movement distance in the forward direction, obtained by the operation of FIG. [Figure 11] 11A and 11B are graphs showing correction values ​​for each movement distance in the negative direction, obtained by the operation of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] An embodiment of a gantry apparatus according to the present invention will be described in detail below with reference to the drawings. In the embodiment described below, an example is shown in which a gantry apparatus having a working head is applied to a component mounting apparatus. The component mounting apparatus is an apparatus that mounts various components on a printed circuit board (workpiece). The working head is a mounting head that picks up and mounts the components. The components include, for example, chip components such as chip resistors and chip capacitors, IC package-type electronic components such as BGA, QFP, or SOP, power-related components such as capacitors and transformers, connectors, and heat sinks. The gantry apparatus according to the present invention is not limited to component mounting apparatuses, but can also be applied to various devices equipped with a working head that performs a predetermined operation on a workpiece placed in a predetermined working area. For example, the gantry apparatus according to the present invention may be applied to devices equipped with a working head that holds a workpiece and moves from a source to a destination, or devices equipped with a working head that performs workpiece processing, joining, cleaning, painting, or drying.

[0020] [Overall structure of component mounting equipment] FIG. 1 is a plan view showing the schematic configuration of a component mounting apparatus 1 to which a gantry device is applied, and FIG. 2 is a front view of the component mounting apparatus 1. The component mounting apparatus 1 is an apparatus for producing mounted boards in which various electronic components are mounted on a board P. In FIGS. 1 and 2 and other figures, XY Cartesian coordinates are used to indicate direction. The X direction is the movement of the board P, and the Y direction is the direction perpendicular to the X direction on a horizontal plane. The directions perpendicular to the X and Y directions are the up and down directions. The X direction corresponds to the "first direction" and the Y direction corresponds to the "second direction" of the present invention. In the following description, the Y1 side of the Y direction may be referred to as the "negative direction," and the Y2 side thereof may be referred to as the "positive direction."

[0021] The component mounting apparatus 1 includes a gantry device 100, and is equipped with a base 2, a board transport unit 3 arranged on the base 2, a component supply unit 5, a head unit 6 serving as a work head, and a component recognition camera 8. The head unit 6 is equipped with a board recognition camera 9. Inside the base 2 is a control device 20 shown in FIG. 3 that controls the operation of each unit of the component mounting apparatus 1.

[0022] The base 2 has a rectangular shape in a plan view, a flat top surface, and is equipped with a board transport unit 3 and a component supply unit 5. The board transport unit 3 is a transport mechanism for the board P on which components are mounted, and has a pair of conveyors 4 that transport the board P in the X direction. The conveyors 4 are belt conveyors that transport the board P from the X1 side into the component mounting apparatus 1, transport it to the X2 side to a predetermined work area, in this case the position of the board P shown in FIG. 1, and stop it there. In this work area, components are mounted on the board P. After the mounting operation, the conveyors 4 transport the board P from the work area to the X2 side and remove it from the component mounting apparatus 1.

[0023] The component supply units 5 supply electronic components to be mounted on the board P. The component supply units 5 are respectively arranged on the Y1 side and the Y2 side of the board transport unit 32. Each component supply unit 5 has a plurality of tape feeders 5F arranged in the X direction. Each tape feeder 5F is equipped with a reel around which a tape is wound, which stores and holds electronic components such as ICs, transistors, resistors, and capacitors at predetermined intervals. The tape feeder 5F intermittently pays out the tape from the reel and supplies the components to the component supply position at the tip of the feeder. Here, a tape feeder 5F is shown as an example, but a stick feeder or tray feeder may also be attached to the component supply unit 5.

[0024] The head unit 6 is a work head that picks up electronic components from the component supply unit 5 and mounts them on the substrate P. The head unit 6 is arranged so that it can move in the X and Y directions above the base 2. The head unit 6 is equipped with a plurality of heads 7. Each head 7 holds and transports an electronic component at the component supply position, and mounts the electronic component on the substrate P. Each head 7 has a nozzle 7a at its bottom that picks up an electronic component.

[0025] The component recognition camera 8 is incorporated into the base 2. The component recognition camera 8 has an imaging field above the base 2, and acquires two-dimensional images of electronic components for component recognition. The component recognition camera 8 captures an image of the component held by the nozzle 7a of the head 7 from the bottom side. Based on the captured image, the state of suction of the component by the nozzle 7a is inspected.

[0026] The board recognition camera 9 is a camera capable of capturing images of the work area of ​​the head unit 6, i.e., the board P carried into the work area. The board recognition cameras 9 are attached to the X1 and X2 side surfaces of the head unit 6. Either the board recognition camera 9 on the X1 or X2 side may be omitted. The board recognition camera 9 captures images of various marks affixed to the surface of the board P present in the work area.

[0027] The marks are, for example, a pair of fiducial marks FM provided on a diagonal line of a rectangular substrate P. The fiducial marks FM are marks for detecting the amount of positional deviation of the work position of the loaded substrate P from the origin coordinates. The positions of the fiducial marks FM are identified on image data obtained by imaging with the substrate recognition camera 9, and the amount of positional deviation from the origin coordinates is determined. This amount of positional deviation is referenced during component mounting, and the components are mounted on the substrate P by the head 7 so that no positional deviation occurs. In this embodiment, the substrate recognition camera 9 is also used to image the plate jig TP (FIG. 5) for obtaining XY movement correction values ​​for the head unit.

[0028] The head unit 6 moves horizontally in the X and Y directions by operation of the head unit drive mechanism 10. The head unit drive mechanism 10 includes a Y-axis drive mechanism 10Y that moves the head unit 6 in the Y direction, and an X-axis drive mechanism 10X that moves it in the X direction. These drive mechanisms 10X and 10Y are configured with linear drive devices.

[0029] A pair of elevated frames 12 extending in the Y direction are erected on the base 2 at positions spaced apart from each other in the X direction. The Y-axis drive mechanism 10Y includes a linear guide 13, a beam 14, and a Y-axis linear motor 15. The linear guide 13 is installed on the upper surface of each of the pair of elevated frames 12 so as to extend in the Y direction. The linear guide 13 includes a first guide 13a on the X1 side and a second guide 13b on the X2 side.

[0030] Beam 14 extends in the X direction and is supported by linear guide 13 so as to be movable in the Y direction. Beam 14 includes a first end 14a on the X1 side and a second end 14b on the X2 side. First guide 13a supports first end 14a of beam 14 so as to be movable in the Y direction. Second guide 13b supports second end 14b so as to be movable in the Y direction. Head unit 6 is mounted on beam 14 so as to be movable in the X direction.

[0031] The Y-axis linear motor 15 corresponds to the "motor" of the present invention and generates a driving force for moving the beam 14 in the Y direction. The Y-axis linear motor 15 is disposed on the elevated frame 12 on the X1 side. That is, the Y-axis linear motor 15 applies a driving force to the first end 14a of the beam 14 to move the beam 14 in the Y direction. On the other hand, no driving force is applied to the second end 14b of the beam 14. That is, no motor is disposed on the elevated frame 12 on the X2 side. As described above, the first end 14a of the beam 14 is supported by the first guide 13a, and the second end 14b is supported by the second guide 13b, but only the first end 14a is applied with a driving force. That is, the gantry apparatus 100 of this embodiment employs the "double-support single-drive" structure described above. When the first end 14a, to which the driving force is applied from the Y-axis linear motor 15, moves in the Y direction, the second end 14b also moves in the Y direction in response.

[0032] Y-axis linear motor 15 includes stator 15a and mover 15b. Stator 15a is composed of a field magnet in which multiple permanent magnets are aligned in the Y direction. Stator 15a is disposed adjacent to linear guide 13 on elevated frame 12 on the X1 side, along linear guide 13. Mover 15b is composed of an armature having multiple electromagnetic coils wound around cores. Mover 15b is disposed on the underside of first end 14a of beam 14, facing stator 15a. When a predetermined drive current is applied to mover 15b, a magnetic field is generated in each electromagnetic coil, generating a thrust force that moves mover 15b in the Y direction. This thrust force is input to first end 14a of beam 14, causing beam 14 to move in the Y direction along the pair of linear guides 13.

[0033] X-axis drive mechanism 10X includes a rail 17 and an X-axis linear motor 18. Rail 17 is attached to beam 14 and extends in the X direction from first end 14a to second end 14b of beam 14. Rail 17 supports head unit 6 movably in the X direction. X-axis linear motor 18 is disposed on beam 14 and generates a driving force for moving head unit 6 in the X direction.

[0034] X-axis linear motor 18 includes stator 18a and mover 18b. Stator 18a is composed of a field magnet in which multiple permanent magnets are arranged in a row in the X direction. Mover 18b is composed of an armature having multiple electromagnetic coils wound around cores. Stator 18a is disposed adjacent to rail 17 and along rail 17. Mover 18b is disposed on head unit 6 in a position facing stator 18a. When a predetermined drive current is applied to mover 18b, a magnetic field is generated in each electromagnetic coil, generating a thrust force that moves mover 18b in the X direction. This thrust force is input to head unit 6, causing head unit 6 to move in the X direction along rail 17.

[0035] As described above, head unit drive mechanism 10 moves beam 14 in the Y direction using Y-axis drive mechanism 10Y, and moves head unit 6 in the X direction relative to beam 14 using X-axis drive mechanism 10X. As a result, head unit 6 can be moved horizontally in the X and Y directions.

[0036] A Y-axis encoder 16 is incorporated into the Y-axis drive mechanism 10Y. The Y-axis encoder 16 is a device for obtaining position information of the beam 14 in the Y direction. An X-axis encoder 19 is incorporated into the X-axis drive mechanism 10X. The X-axis encoder 19 is a device for obtaining position information of the head unit 6 in the X direction.

[0037] The Y-axis encoder 16 is disposed on the elevated frame 12 on the X1 side at a position adjacent to the X2 side of the first guide 13a. The Y-axis encoder 16 includes a linear scale 16a and a scale head 16b. The linear scale 16a is disposed on the elevated frame 12 on the X1 side along the first guide 13a. The scale head 16b detects position information of the linear scale 16a. The scale head 16b is attached to the underside of the first end 14a of the beam 14 at a position where the position information of the linear scale 16a can be detected.

[0038] X-axis encoder 19 is disposed adjacent to rail 17 of beam 14. X-axis encoder 19 includes a linear scale 19a and a scale head 19b. Linear scale 19a is disposed along rail 17 on the side of beam 14. Scale head 19b detects position information of linear scale 19a. Scale head 19b is attached to head unit 6 at a position where it can detect position information of linear scale 19a.

[0039] According to the component mounting apparatus 1 described above, when a board P is carried into the work area along the conveyor 4, the head unit 6 moves back and forth between the component supply unit 5 and the board P placed in the work area. The head 7 picks up components from the tape feeder 5F and mounts the components in predetermined positions on the board P. As the head unit 6 moves back and forth, the components picked up by each head 7 are imaged by the component recognition camera 8, and the position of the head unit 6 is corrected based on the recognition results. When mounting of all components on the board P is completed, the board P is carried out of the work area, and the next board P is carried into the work area. By repeating these operations of each unit, component-mounted boards are produced.

[0040] In the component mounting apparatus 1 of this embodiment, the control device 20 described below corresponds to the "controller" of the present invention. The gantry apparatus 100 of this embodiment is composed of the control device 20, the beam 14, the head unit 6, the board recognition camera 9, and the head unit drive mechanism 10.

[0041] [Electrical configuration of component mounting equipment] Next, the control configuration of the component mounting apparatus 1 will be described. FIG. 3 is a block diagram showing the electrical configuration of the component mounting apparatus 1. The component mounting apparatus 1 includes a control device 20 disposed on the base 2. The control device 20 controls the operation of each part of the component mounting apparatus 1, including the operation of the head unit drive mechanism 10 and various cameras. FIG. 3 also shows a Z-axis servo motor 27 and an R-axis servo motor 28, which are not shown in FIGS. 1 and 2. The Z-axis servo motor 27 and the R-axis servo motor 28 are motors incorporated into the head unit 6. The Z-axis servo motor 27 is a drive source that raises and lowers the head 7 along the Z axis when the head 7 picks up or mounts components. The R-axis servo motor 28 is a drive source that rotates the head 7 around the R axis.

[0042] The control device 20 is made up of a processor and the like that operates by loading a predetermined program, and functionally comprises an imaging control unit 21, an image processing unit 22, an axis control unit 23, a main control unit 24, and a storage unit 25.

[0043] The imaging control unit 21 controls the imaging operations of the component recognition camera 8, the board recognition camera 9, and various other cameras provided in the component mounting apparatus 1. For example, the imaging control unit 21 provides these cameras with control signals that specify the timing at which they perform imaging operations and control signals that specify exposure times. In this embodiment, before the head unit 6 performs component mounting work, the imaging control unit 21 causes the board recognition camera 9 to perform imaging to acquire a movement correction value for the head unit 6.

[0044] Image processing unit 22 applies image processing techniques such as edge detection processing and pattern recognition processing involving feature extraction to image data acquired by component recognition camera 8, board recognition camera 9, and the like, to extract various types of information from the images. Specifically, image processing unit 22 performs processing to identify the shape, position, and the like of the component held by nozzle 7a, based on the image data acquired by component recognition camera 8. Image processing unit 22 also performs processing to identify the positions of fiducial mark F on board P and fiducial marks FM and marks MA on plate jig TP, which will be described later, based on the image data acquired by board recognition camera 9.

[0045] Axis control unit 23 controls the movement of head unit 6 in the X and Y directions by controlling Y-axis linear motor 15 and X-axis linear motor 18. During this X and Y movement, correction values ​​acquired by imaging using plate jig TP before the component mounting operation is performed are referenced. Axis control unit 23 also controls the lifting and rotation of head 7 by controlling Z-axis servo motor 27 and R-axis servo motor 28 provided in head unit 6.

[0046] The main control unit 24 comprehensively controls various operations of the component mounting apparatus 1. For example, the main control unit 24 provides control signals to the imaging control unit 21, image processing unit 22, axis control unit 23, etc., causing them to perform operations such as capturing an image, performing image processing on image data, and driving the head unit 6 and head 7. The main control unit 24 functionally includes a correction operation control unit 241, a correction value calculation unit 242, and a mounting control unit 243, with regard to movement control of the head unit 6.

[0047] The correction operation control unit 241 controls a process for acquiring a movement correction value for the XY movement of the head unit 6 before the head unit 6 performs a component mounting operation. The correction operation control unit 241 sequentially causes the Y-axis linear motor 15 to perform a first movement that moves the beam 14 in the positive Y direction (Y2 side) and a second movement that moves the beam 14 in the negative Y direction (Y1 side), opposite to the positive direction. While performing the first movement or the second movement, the correction operation control unit 241 causes the board recognition camera 9 to capture an image of the plate jig TP placed in the work area of ​​the component mounting apparatus 1. As shown in FIG. 5, the plate jig TP has a rectangular shape in a plan view and includes a plurality of marks MA arranged in a matrix and a plurality of fiducial marks FM placed at the corners of the rectangle.

[0048] The correction value calculation unit 242 calculates the error between the position of the mark MA identified based on the image captured during the first movement or the second movement and the theoretical position of the mark MA. Then, the correction value calculation unit 242 calculates a first correction value for correcting the error during the first movement and a second correction value for correcting the error during the second movement. These correction values ​​are used to correct the difference between the position reached when the head unit 6 is moved in the XY directions by the current head unit drive mechanism 10 and the theoretical component mounting position.

[0049] After the component is picked up by the component supply unit 5, the mounting control unit 243 moves the head unit 6 to a movement target position corresponding to the component mounting position on the board P. At this time, the mounting control unit 243 sets the movement target position by referring to the movement correction value of the head unit 6. In this embodiment, different movement correction values ​​are used depending on the movement direction of the beam 14, such as a first correction value when moving the head unit 6 (beam 14) in the positive Y direction and a second correction value when moving in the negative Y direction.

[0050] The storage unit 25 stores various types of information related to the substrate P and electronic components, various setting values ​​and parameters, control data, operation programs, etc. related to the component mounting apparatus 1. The storage unit 25 also stores various types of information related to the substrate P, the components to be mounted, and the jigs to be used. Furthermore, the storage unit 25 stores first and second correction values ​​according to the positive and negative movement directions of the head unit 6 that are acquired before the component mounting operation is performed.

[0051] [First embodiment] <Correction value acquisition process> Fig. 4 is a flowchart showing a first embodiment of the process for acquiring movement correction values ​​for the head unit 6, which is executed before component mounting work in the component mounting apparatus 1. Fig. 5 is a plan view showing the gantry device 100 of the component mounting apparatus 1. First, the plate jig TP is installed in the working area WA of the component mounting apparatus 1 (step S1). The working area WA is an area where the board P is placed during component mounting work. The plate jig TP is carried into the working area WA by the board transport unit 3 and fixed by a fixing unit (not shown).

[0052] Next, the correction operation control unit 241 causes the board recognition camera 9 mounted on the head unit 6 to capture an image of the plate jig TP (step S2). The image capture in step S2 is for identifying the position and posture of the loaded plate jig TP in the working area WA based on the fiducial marks FM. The image data acquired in step S2 is sent to the image processing unit 22, which identifies the coordinates of the multiple fiducial marks FM provided on the plate jig TP through image processing. Based on these fiducial marks FM, the coordinates of each mark MA are also identified (step S3). The coordinates identified here are treated as the theoretical position of the mark MA.

[0053] Next, the correction operation control unit 241 causes the board recognition camera 9 to capture an image of the plate jig TP while sequentially moving the beam 14 in the positive direction (hereinafter referred to as the positive direction Y2) and the negative direction (hereinafter referred to as the negative direction Y1) of the Y direction. Fig. 6(A) is a plan view showing a situation in which the second movement of the beam 14 in the negative direction Y1 is being performed, and Fig. 6(B) is a plan view showing a situation in which the first movement of the beam 14 in the positive direction Y2 is being performed. Note that Figs. 6(A) and (B) show simplified illustrations of the Y-axis linear motor 15.

[0054] As described above, the gantry apparatus 100 employs a double-support single-drive structure. Only the first end 14a of the beam 14 receives driving force to move the beam 14 in the Y direction. The position of the first end 14a, to which driving force is input from the Y-axis linear motor 15, can be accurately determined based on the measurement value of the Y-axis encoder 16, i.e., the value of the linear scale 16a. However, the position of the second end 14b, to which no encoder is provided, cannot be accurately determined. Therefore, it is unclear whether the second end 14b is positioned at the intended position when the Y-axis linear motor 15 stops. This is because the second end 14b may not move to the same Y-direction position as the first end 14a due to factors such as warping of the beam 14 and frictional resistance between the second guide 13b and the second end 14b.

[0055] Generally, the movement of the second end 14b lags behind the first end 14a. That is, as shown in FIG. 6A, when the beam 14 moves in the negative direction Y1, the beam 14 is tilted so that the first end 14a, to which the driving force is input, leads the second end 14b on the non-driven side in the negative direction Y1. That is, the beam 14 is tilted so that the second end 14b moves in the positive direction Y2 with respect to the X-direction line. Conversely, as shown in FIG. 6B, when the beam 14 moves in the positive direction Y2, the beam 14 is tilted so that the first end 14a on the driven side leads the second end 14b on the non-driven side in the positive direction Y2. Therefore, when the head unit 6 performs component mounting work, a movement correction value for the beam 14 that takes the above-mentioned delay into account must be provided to the axis control unit 23.

[0056] According to experiments conducted by the inventors, the movement characteristics of the beam 14 differ between the negative direction Y1 and the positive direction Y2. In short, the manner in which the second end 14b is delayed relative to the first end 14a differs between the negative direction Y1 and the positive direction Y2. Therefore, if the movement correction value of the beam 14 is set to be uniform in the negative direction Y1 and the positive direction Y2, appropriate movement correction may not be possible. Therefore, in this embodiment, a first correction value for when the beam 14 (head unit 6) is moved in the positive direction Y2 and a second correction value for when the beam 14 is moved in the negative direction Y1 are acquired in advance.

[0057] The correction operation control unit 241 moves the beam 14 in the forward direction Y2 via the axis control unit 23, while causing the board recognition camera 9 to capture an image of the plate jig TP via the imaging control unit 21 (step S4). The correction value calculation unit 242 sends the image data acquired by the imaging in step S4 to the image processing unit 22, and causes the image processing unit 22 to execute a process of identifying the position of the mark MA based on the image. The correction value calculation unit 242 calculates the error between the position of the mark MA on the image of a certain position of interest and the theoretical position of the mark MA at the position of interest derived in step S3 (step S5).

[0058] Furthermore, the correction value calculation unit 242 calculates a first correction value for correcting the error (step S6). As shown in Fig. 6, the first correction value is a correction value that fills in the positive direction deviation amount d2 of the coordinate DS2 of the mark MA at the position of interest calculated from the image with respect to the theoretical coordinate DS of the mark MA at the position of interest. The obtained first correction value is stored in the memory unit 25.

[0059] Next, the correction operation control unit 241 moves the beam 14 in the negative direction Y1 while causing the board recognition camera 9 to capture an image of the plate jig TP (step S7). The correction value calculation unit 242 causes the image processing unit 22 to identify the position of the mark MA based on the image captured in step S7. The correction value calculation unit 242 calculates the error between the position of the mark MA on the image at a certain position of interest and the theoretical position of the mark MA at that position of interest derived in step S3 (step S8). Furthermore, the correction value calculation unit 242 calculates a second correction value for correcting the error (step S9). As shown in FIG. 6, the second correction value is a correction value that compensates for the positive direction deviation d1 of the coordinate DS1 of the mark MA at the position of interest determined from the image with respect to the theoretical coordinate DS of the mark MA at the position of interest. The obtained first correction value is stored in the memory unit 25.

[0060] In the above process, movement of the beam 14 in the negative direction Y1 may precede steps S4 to S6. In other words, steps S7 to S9 may precede steps S4 to S6. Also, imaging of the plate jig TP in the negative direction Y1 and the positive direction Y2 may precede the process of deriving the correction values. In other words, step S7 may be executed following step S4, and the acquired image data may be temporarily stored in the storage unit 25 or a memory area, after which steps S5, S6, S8, and S9 may be executed.

[0061] 7A and 7B are graphs showing examples of correction values ​​obtained by the operation of FIG. 6. FIG. 7A shows the X-direction correction values ​​for each X-axis position of the head unit 6. FIG. 7B shows the Y-direction correction values ​​for each X-axis position. The right ends of these graphs correspond to the first end 14a on the driving side, and the left ends correspond to the second end 14b on the non-driving side. In FIG. 7A, the first correction value when moving the beam 14 in the positive direction Y2 is graph Y2-X, and the second correction value when moving the beam 14 in the negative direction Y1 is graph Y1-X. In FIG. 7B, the first correction value when moving the beam 14 in the positive direction Y2 is graph Y2-Y, and the second correction value when moving the beam 14 in the negative direction Y1 is graph Y1-Y.

[0062] As is clear from these graphs, there is little difference in the correction values ​​between the negative direction Y1 and the positive direction Y2 near the drive side, but the difference becomes greater as you move toward the non-drive side. This shows that the movement characteristics of the beam 14 differ between the negative direction Y1 and the positive direction Y2. The reason the correction values ​​for both directions are nearly identical near the drive side is because the Y-axis linear motor 15 and Y-axis encoder 16 are located on the drive side, so the movement error itself is small. In this way, by setting correction values ​​for the positive and negative movement of the beam 14, rather than a uniform correction value, it becomes possible to accurately move the head unit 6 to the required mounting position.

[0063] <Head unit movement control during component mounting work> Next, an example of movement control of the head unit 6 during component mounting work using the above-described first and second correction values ​​will be described with reference to the flowchart shown in Fig. 8. The mounting control unit 243 of the main control unit 24 acquires a command signal related to the movement position of the head unit 6 (step S11). The designation signal is data of a movement target for the head unit 6, which is given based on data on the board P, data on the components to be mounted, data on the mounting positions of the components, etc.

[0064] The mounting control unit 243 determines whether the movement direction of the head unit 6 is the positive direction Y2 (step S12). If the movement direction is the positive direction Y2 (YES in step S12), the mounting control unit 243 accesses the first correction value from the storage unit 25 (graph Y2-X, graph Y2-Y in the example of FIG. 7) and reads out the first correction value of XY corresponding to the X-axis position of the movement target (step S13). If the movement direction is the negative direction Y1 (NO in step S12), the mounting control unit 243 accesses the second correction value from the storage unit 25 (graph Y2-X, graph Y2-Y in the example of FIG. 7) and reads out the second correction value of XY corresponding to the X-axis position of the movement target (step S14).

[0065] Next, the mounting control unit 243 sets the current movement target position of the head unit 6 by applying the correction value acquired in step S13 or S14 to the movement target data acquired in step S11 (step S15). That is, the mounting control unit 243 sets the movement target position using the first correction value when the movement direction of the beam 14 is the positive direction Y2, and sets the movement target position using the second correction value when the movement direction is the negative direction Y1.

[0066] This movement target position is given to the axis control unit 23, and the axis control unit 23 operates the Y-axis linear motor 15 and the X-axis linear motor 18 so that the head 7 of the head unit 6 moves to the movement target position (step S16). Thereafter, the mounting control unit 243 checks whether or not there is a command regarding the next movement position of the head unit 6 (step S17). If there is a next movement position (YES in step S17), the process returns to step S11 and is repeated. If there is no next movement position (NO in step S17), the process ends.

[0067] [Second embodiment] In the second embodiment, an example is shown in which the correction value is acquired taking into consideration not only the movement direction of the beam 14 but also the movement distance or acceleration / deceleration of the beam 14. That is, the movement distance or acceleration / deceleration of the beam 14 is changed for each of the movement of the beam 14 in the positive direction Y2 (first movement) and the movement of the beam 14 in the negative direction Y1 (second movement), and the substrate recognition camera 9 is made to capture images of the mark MA on the plate jig TP. The error between the position of the mark MA identified based on the images acquired by these images and the theoretical position of the mark MA is calculated, and a first correction value and a second correction value are calculated for each movement distance or acceleration / deceleration.

[0068] 9(A) and 9(B) are plan views showing how movement correction values ​​are acquired for different movement distances of the beam 14 according to the second embodiment of the present invention. Both of FIGS. 9(A) and 9(B) show examples in which the beam 14 is moved in the forward direction Y2, but by different distances. FIG. 9(A) shows a state in which the beam 14 is moved in the forward direction Y21 by a short distance (e.g., 1 mm), and FIG. 9(B) shows a state in which the beam 14 is moved in the forward direction Y22 by a long distance (e.g., 20 mm).

[0069] The correction operation control unit 241 causes the board recognition camera 9 to capture an image of the plate jig TP while moving the beam 14 a short distance Y21 and a long distance Y22 in the forward direction. While the beam 14 is moved 1 mm and 20 mm in this example, the correction value acquisition operation may be performed in multiple steps. For example, the beam 14 is moved in increments of 2 mm, 5 mm, 10 mm, 20 mm, and 50 mm, and the board recognition camera 9 captures an image of the plate jig TP at each movement. The correction value calculation unit 242 calculates the error between the position of the mark MA captured in each image and the theoretical position of the mark MA and calculates a first correction value for each movement distance. Similarly, the beam 14 is moved by various distances in the negative direction Y1 to capture an image of the plate jig TP, and a second correction value for each movement distance is acquired.

[0070] Different movement distances may result in different movement characteristics of the beam 14. This is because, depending on the movement distance, the acceleration / deceleration of the beam 14 and the movement time at the upper limit speed required to start the movement of the beam 14 from the current position and stop the beam 14 at the target end point may differ. While exaggerated in FIG. 9 , for example, the degree of delay of the second end 14b relative to the first end 14a may be greater in the case of a long-distance forward movement Y22 than in the case of a short-distance forward movement Y21. Therefore, setting a uniform first correction value for the forward direction Y2 may not result in accurate error correction. In light of this, in the second embodiment, imaging operations for acquiring correction values ​​and calculation of first and second correction values ​​are performed for each movement distance of the beam 14 in each of the forward direction Y2 and the negative direction Y1.

[0071] Furthermore, even if the movement distance is the same, the acceleration / deceleration may be intentionally changed to switch between high-speed and low-speed implementation or to activate a power-saving mode. In this case, the movement characteristics of the beam 14 may also differ. Therefore, the imaging operation for acquiring the correction values ​​and the calculation of the first and second correction values ​​may be performed at different acceleration / deceleration speeds in the positive direction Y2 and the negative direction Y1.

[0072] The process of acquiring the movement correction value of the head unit 6 in the second embodiment is substantially the same as the process shown in the flowchart of FIG. 4 described in the first embodiment. For the positive direction Y2, the processes of steps S4 to S6 are repeated for each predetermined movement distance. For the negative direction Y1, the processes of steps S7 to S9 are repeated for each predetermined movement distance. The movement control of the head unit 6 during component mounting work is also substantially the same as that in FIG. 8. In step S13 or step S14, the first or second correction value set for each movement distance is read out, and the movement target position in step S15 is set.

[0073] 10(A) and 10(B) are graphs showing correction values ​​for each movement distance in the forward direction Y2. FIG. 10(A) is a graph showing the X-direction correction value for each X-axis position and movement distance when the head unit 6 is moved in the forward direction Y2, and FIG. 10(B) is a graph showing the Y-direction correction value for each X-axis position and movement distance. The right ends of these graphs correspond to the first end 14a on the driving side, and the left ends correspond to the second end 14b on the non-driving side. In FIG. 10(A), graph Y21-X represents the first correction value for a movement distance in the forward direction Y2 of 5 mm, graph Y22-X represents the first correction value for a movement distance of 10 mm, graph Y23-X represents the first correction value for a movement distance of 20 mm, and graph Y24-X represents the first correction value for a movement distance of 50 mm. In FIG. 10B, graph Y21-Y is the first correction value for a movement distance in the forward direction Y2 of 5 mm, graph Y22-Y is the first correction value for a movement distance of 10 mm, graph Y23-Y is the first correction value for a movement distance of 20 mm, and graph Y24-Y is the first correction value for a movement distance of 50 mm.

[0074] 11(A) and (B) are graphs showing correction values ​​for each movement distance in the negative direction Y1. FIG. 11(A) is a graph showing the X-direction correction value for each X-axis position and movement distance when the head unit 6 is moved in the negative direction Y1, and FIG. 11(B) is a graph showing the Y-direction correction value for each X-axis position and movement distance. The right ends of these graphs correspond to the first end 14a on the driving side, and the left ends correspond to the second end 14b on the non-driving side. In FIG. 11(A), graph Y11-X represents the second correction value for a movement distance in the negative direction Y1 of 5 mm, graph Y12-X represents the second correction value for a movement distance of 10 mm, graph Y13-X represents the second correction value for a movement distance of 20 mm, and graph Y14-X represents the second correction value for a movement distance of 50 mm. In FIG. 11(B), graph Y11-Y is the second correction value for a movement distance in the negative direction Y1 of 5 mm, graph Y12-Y is the second correction value for a movement distance of 10 mm, graph Y13-Y is the second correction value for a movement distance of 20 mm, and graph Y14-Y is the second correction value for a movement distance of 50 mm.

[0075] According to the second embodiment, as correction values ​​for moving the beam 14 in the positive direction Y2 or the negative direction Y1, the beam 14 is moved at different movement distances or acceleration / deceleration speeds, and first and second correction values ​​for each movement distance or acceleration / deceleration speed are calculated. The correction value calculation unit 242 sets the movement target position using a correction value according to the movement distance or acceleration / deceleration speed of the beam 14, rather than a uniform correction value. Therefore, the head unit 6 can be moved to the required position more accurately. [Explanation of symbols]

[0076] 1. Component mounting equipment 4 Conveyor 5. Parts Supply Department 6 Head unit (working head) 7 heads 9. Circuit board recognition camera (camera) 13 Linear guide 13a, 13b 1st Guide, 2nd Guide 14 Beam 15 Y-axis linear motor (motor) 20 Control device (control unit) 100 Gantry device P board (work) TP Plate Jig MA mark WA Work Area Y1 Negative direction (second direction) Y2 Positive direction (1st direction)

Claims

1. a beam having a first end and a second end and extending in a first direction; a work head that is mounted on the beam and is movable in the first direction, and that performs a predetermined operation on a workpiece placed in a preset work area; a camera mounted on the work head and capable of capturing an image of the work area; a linear guide extending in a second direction perpendicular to the first direction and including a first guide movably supporting the first end of the beam and a second guide movably supporting the second end; a motor that applies a driving force to the first end of the beam to move the beam in the second direction; a control unit that controls the camera and the motor, The control unit, before the work head performs the predetermined work, While the motor sequentially performs a first movement that moves the beam in the positive direction of the second direction and a second movement that moves the beam in the negative direction opposite to the positive direction, the camera is caused to capture an image of a plate jig having a plurality of marks arranged in the working area; calculating an error between the position of the mark specified based on the image and a theoretical position of the mark, and calculating a first correction value for correcting the error in the first movement and a second correction value for correcting the error in the second movement; a gantry device that, during the specified operation by the working head, sets a movement target position using the first correction value when moving the beam in the positive direction of the second direction, and sets a movement target position using the second correction value when moving the beam in the negative direction.

2. 2. The gantry apparatus according to claim 1, The control unit calculates errors for each of the first and second movements by varying the movement distance or acceleration / deceleration of the beam, and calculates the first correction value and the second correction value for each movement distance or acceleration / deceleration.

3. a beam having a first end and a second end and extending in a first direction; a work head that is mounted on the beam and is movable in the first direction, and that performs a predetermined operation on a workpiece placed in a preset work area; a camera mounted on the work head and capable of capturing an image of the work area; a linear guide extending in a second direction perpendicular to the first direction and including a first guide movably supporting the first end of the beam and a second guide movably supporting the second end; a motor that applies a driving force to the first end of the beam to move the beam in the second direction; a control unit that controls the camera and the motor, The control unit, before the work head performs the predetermined work, causing the motor to sequentially move the beam in the second direction at different moving distances or at different acceleration / deceleration speeds, while causing the camera to capture images of a plate jig having a plurality of marks arranged in the working area; calculating an error between the position of the mark specified based on the image and a theoretical position of the mark, and calculating a correction value for correcting the error for each of the different movement distances or acceleration / deceleration rates; A gantry device that sets a movement target position of the beam using the correction value according to the movement distance or acceleration / deceleration of the beam during the predetermined operation by the work head.

4. 4. The gantry apparatus according to claim 1, The workpiece is a substrate on which electronic components are mounted, a gantry apparatus, wherein the work head is a mounting head that mounts the electronic component on the substrate;

5. A gantry apparatus according to any one of claims 1 to 3; a conveyor that carries the substrate as the workpiece into and out of the working area; a component supply unit that supplies electronic components to be mounted on the board, The component mounting apparatus, wherein the work head is a mounting head that picks up the electronic component from the component supply unit and mounts it on the board.

Images