Workpiece mounting device

Abstract

To provide a workpiece mounting device in which when another workpiece is mounted on the basis of a workpiece first mounted on a substrate, the mounting accuracy of the another workpiece can be enhanced.SOLUTION: A component mounting device 1 as the workpiece mounting device includes: a head unit 4 including a head 4H for mounting a workpiece on a substrate P; a movable camera 5 and a fixed camera 6 assembled in the head unit; and a control part 7 for controlling the operations of the head unit 4 and the cameras 5 and 6. The control part 7 allows the movable camera 5 to focus on marks M11 and M12 existing on the upper surfaces of first components C11 and C12 mounted on the substrate P and to perform imaging and allows the head 4H to mount second components C21 and C22 on the upper surfaces of the first components C11 and C12 on the basis of positional information of the marks M11 and M12 obtained by the imaging.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a workpiece mounting device having a head that holds a workpiece and mounts it on a substrate. [Background technology]

[0002] A workpiece mounting device that mounts workpieces such as electronic components onto a circuit board includes a head that sucks and holds the workpiece. A head unit equipped with the head is equipped with a camera for performing image recognition of the workpiece and the circuit board. Patent Document 1 discloses a workpiece mounting device in which a head unit is equipped with a camera that captures an image of a fiducial mark on the circuit board and a camera that captures an image of the workpiece held by the head. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-170080 Summary of the Invention [Problem to be solved by the invention]

[0004] In a workpiece mounting device, in addition to simply mounting a workpiece on a board, it is sometimes necessary to mount another workpiece based on an already mounted workpiece. For example, there are cases where it is necessary to mount another workpiece on top of a workpiece mounted on a board, or to mount a workpiece based on a jig mounted on the board. In such cases, it has sometimes been difficult to mount the workpiece accurately in a predetermined position on the board.

[0005] An object of the present invention is to provide a workpiece mounting device that can improve the mounting accuracy of another workpiece when another workpiece is mounted on a substrate based on a workpiece that has already been mounted on the substrate. [Means for solving the problem]

[0006] A workpiece mounting device according to one aspect of the present invention comprises a head unit including a head for mounting a workpiece onto a substrate, a first camera assembled to the head unit, and a control unit for controlling the operation of the head unit and the first camera, wherein the control unit focuses the first camera on a first feature portion present on the top surface of a first workpiece mounted on the substrate to take an image, and causes the head to mount a second workpiece at a predetermined position on the substrate based on position information of the first feature portion obtained by the image capture.

[0007] According to this aspect, the second workpiece can be mounted using the position of the first characteristic portion of the first workpiece already mounted on the substrate as a reference, which allows for improved mounting accuracy when the second workpiece is mounted at a position associated with the mounting position of the first workpiece, compared to when the second workpiece is mounted using a positioning mark on the substrate or the like as a reference.

[0008] In the above workpiece mounting device, the first workpiece may be a first component to be mounted on a board, and the second workpiece may be a second component to be mounted on the first component.

[0009] According to this aspect, the second workpiece can be placed on the first workpiece using the position of the first characteristic portion of the first workpiece as a reference, and therefore the second workpiece can be placed at a predetermined position on the first workpiece with high precision.

[0010] In the above-mentioned work mounting device, the first camera may be a movable camera attached to the head unit so as to be movable up and down, and the control unit may focus the movable camera on the first characteristic portion by moving the movable camera up and down.

[0011] According to this aspect, by moving the movable camera up and down, it is possible to focus on the first feature portion present on the top surface of the first workpiece, which has various heights. It is also possible to focus on a location other than the top surface of the first workpiece. For example, the first camera can be made to capture images of positioning marks on a circuit board, thereby expanding the range of use of the first camera.

[0012] In the above-mentioned workpiece mounting device, it is desirable that the device further includes a second camera that is fixedly attached to the head unit and whose operation is controlled by the control unit, and the control unit causes the second camera to capture an image of a second feature portion present on the top surface of the substrate, and causes the head to mount a first workpiece at a predetermined position on the substrate based on position information of the second feature portion obtained by the image capture.

[0013] According to this aspect, a second camera is provided in addition to the first camera, and the second camera captures an image of the second feature portion of the substrate. The first workpiece is mounted on the substrate based on the position information of the captured second feature portion, thereby improving the mounting accuracy of the first workpiece. Furthermore, since it is not necessary to capture an image of the second feature portion with the first camera, productivity can be improved.

[0014] In the above-mentioned work mounting device, when a plurality of the first workpieces are mounted on the substrate, it is desirable that the control unit causes the first camera to sequentially capture images of the first characteristic portions present on the top surfaces of the plurality of first workpieces.

[0015] According to this aspect, the first characteristic portions of the plurality of first workpieces are sequentially imaged, so that the efficiency of the image capturing operation by the first camera can be improved.

[0016] In the above-mentioned work mounting device, when the first work is mounted at least at a first position and a second position on the substrate, and the height of the top surface of the first work at the first position is set to a first height and the height of the top surface of the first work at the second position is set to a second height, the control unit may sequentially capture images of the first characteristic portions present on the top surface of the first work at the first position and the second position without moving the movable camera in the vertical direction when the difference between the first height and the second height is within a predetermined range.

[0017] According to this aspect, the top surface of the first workpiece at the first position and the second position can be imaged without moving the mobile camera in the vertical direction. Therefore, the efficiency of the imaging operation of the first feature portion by the mobile camera can be improved. Note that "the difference is within a predetermined range" means, for example, that the difference in height between the first height and the second height falls within the depth of field of the mobile camera.

[0018] In the above-mentioned work mounting device, when the first work is mounted at least at a first position and a second position on the substrate, and the height of the top surface of the first work at the first position is a first height and the height of the top surface of the first work at the second position is a second height, the control unit may, when the difference between the first height and the second height exceeds a predetermined range, cause the moving camera to capture an image of the first characteristic portion present on the top surface of the first work at the first position, and after moving the moving camera in the vertical direction, cause the moving camera to capture an image of the first characteristic portion present on the top surface of the first work at the second position.

[0019] According to this aspect, the moving camera can be caused to sequentially focus on the top surface of the first workpiece at the first position and the second position, and capture images of the first characteristic portion. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide a workpiece mounting device that can improve the mounting accuracy of another workpiece when another workpiece is mounted on a substrate based on a workpiece that has already been mounted on the substrate. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a plan view showing a schematic configuration of a component mounting device, which is an example of a workpiece mounting device of the present invention. [Figure 2] FIG. 2 is a side view showing a schematic configuration of a head unit portion of the component mounting apparatus. [Figure 3] FIG. 3 is a block diagram showing the electrical configuration of the component mounting apparatus. [Figure 4]FIG. 4 is a side view for explaining the imaging operations of the mobile camera and the fixed camera mounted on the head unit. [Figure 5] 5(A) to 5(D) are side views showing the first embodiment of the present invention. [Figure 6] 6(A) to 6(D) are top views showing the second embodiment. [Figure 7] FIG. 7 is a side view showing the third embodiment. [Figure 8] 8(A) and (B) are side views showing another example of the third embodiment. [Figure 9] FIG. 9 is a flowchart showing a control flow of the imaging operation by the head unit. [Figure 10] FIG. 10 is a side view showing an example in which images are captured by a mobile camera and a fixed camera in one movement cycle of the head unit. DETAILED DESCRIPTION OF THE INVENTION

[0022] Embodiments of a workpiece mounting device according to the present invention will be described in detail below with reference to the drawings. In the embodiments described below, a component mounting device is shown as an example of a workpiece mounting device. The component mounting device is a device that mounts various components as workpieces onto a printed circuit board. 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 workpiece mounting device of the present invention is not limited to component mounting devices, but can also be applied to component holding devices and component moving devices that have heads. The workpieces held by the heads may be mechanical parts or molded parts made of metal, resin, rubber, wood, or the like.

[0023] [Overall structure of component mounting equipment] Fig. 1 is a plan view showing the schematic configuration of component mounting apparatus 1, and Fig. 2 is a side view showing the schematic configuration of a head unit portion of component mounting apparatus 1. Component mounting apparatus 1 is an apparatus that produces mounted boards on which various electronic components are mounted on a substrate P. In Figs. 1 and 2, directions X, Y, and Z are indicated. In the following description, the X direction may be referred to as the left-right direction that is the direction of movement of substrate P, the Y direction as the front-rear direction, and the Z direction as the up-down direction.

[0024] The component mounting apparatus 1 includes a base section 10, and a board transport section 2, a component supply section 3, a head unit 4, and a component recognition camera 11, which are arranged on the base section 10. The base section 10 is provided with a control section 7 that controls the operation of each section of the component mounting apparatus 1. The head unit 4 is equipped with a plurality of heads 4H, and is also equipped with a movable camera 5 (first camera) and a fixed camera 6 (second camera).

[0025] The base unit 10 is a rectangular base with a flat top surface, and has a board transport unit 2 and a component supply unit 3 attached to it. The board transport unit 2 transports the board P on which components are to be mounted. The board transport unit 2 has a pair of conveyors 21 and 22 on the base unit 10 that transport the board P left and right. The conveyors 21 and 22 transport the board P into the component mounting apparatus 1 from the right side, transport it leftward to a predetermined work position, here the position of the board P shown in FIG. 1, and stop it there. At this work position, components are mounted on the board P. After the mounting work, the conveyors 21 and 22 transport the board P leftward and out of the component mounting apparatus 1.

[0026] The component supply units 3 supply components to be mounted on the board P. The component supply units 3 are arranged in the front-to-rear direction of the board transport unit 2. Each component supply unit 3 has multiple tape feeders 31 arranged in the left-to-right direction. Each tape feeder 31 is equipped with a reel around which tape is wound, which stores and holds electronic components such as ICs, transistors, resistors, and capacitors at predetermined intervals. The tape feeders 31 intermittently pay out tape from the reels and supply the components to the component supply position at the tip of the feeder. While a tape feeder 31 is shown here as an example, a tray on which large electronic components or other components are placed may also be attached to the component supply unit 3.

[0027] The head unit 4 takes out components from the component supply unit 3 and mounts them on the substrate P. The head unit 4 is arranged above the base unit 10 so as to be movable in the X and Y directions. The head unit 4 takes out components from the tape feeder 31 at the component supply position, and mounts the components C at predetermined positions on the substrate P at the work position. A support beam 23 extending in the X direction is erected above the base unit 10. The head unit 4 is movably supported on an X-axis fixed rail 24 fixed to the support beam 23.

[0028] Both ends of support beam 23 are supported by Y-axis fixed rails 25 extending in the Y direction, and support beam 23 is movable in the Y direction along these Y-axis fixed rails 25. An X-axis servo motor 26 and a ball screw shaft 27 are disposed relative to X-axis fixed rail 24. A Y-axis servo motor 28 and a ball screw shaft 29 are disposed relative to Y-axis fixed rail 25. Head unit 4 moves in the X direction as ball screw shaft 27 is rotationally driven by X-axis servo motor 26, and moves in the Y direction as ball screw shaft 29 is rotationally driven by Y-axis servo motor 28.

[0029] The head unit 4 is equipped with a plurality of heads 4H. Each head 4H holds and transports components as workpieces, and mounts the components on a substrate P. In this embodiment, an example is shown in which a total of six heads 4H are arranged in a row in the X direction. Each head 4H includes a shaft 41 extending in the Z direction and a suction nozzle 42 attached to the lower end of the shaft 41. The shaft 41 can move up and down relative to the head unit 4 and rotate around the nozzle central axis (R axis). The suction nozzle 42 picks up and holds the components, and mounts them on the surface of the substrate P.

[0030] The component recognition camera 11 is incorporated into the base unit 10. The component recognition camera 11 has an imaging field of view above the base unit 10, and acquires a two-dimensional image of the component for component recognition. The component recognition camera 11 captures an image of the component held by the suction nozzle 42 of the head 4H from the bottom side. Based on the captured image, the state of suction of the component by the suction nozzle 42 is inspected.

[0031] The mobile camera 5 is a fixed-focus camera mounted on the left side of the head unit 4 so as to be movable up and down relative to the head unit 4. The mobile camera 5 captures images of various marks attached to the top surfaces of components mounted on the board P carried into the work position by the conveyors 21 and 22, or to the top surface of a jig placed on the board P. The height position of the marks may vary depending on the thickness of the components and the height of the jig. The mobile camera 5 moves up and down to obtain focused images of marks at different height positions. Note that a camera device having an optical system that can optically change the focus position may be mounted in a fixed state to the head unit 4 instead of the mobile camera 5.

[0032] The head unit 4 is equipped with a camera movement motor 45 and a camera movement axis 46 as mechanisms for moving the mobile camera 5 up and down. The camera movement motor 45 is a drive source for moving the mobile camera 5 up and down. The camera movement axis 46 is a ball screw that extends in the vertical direction on the side of the head unit 4. The camera movement motor 45 drives the camera movement axis 46 to rotate forward or backward around its axis, causing the mobile camera 5 to move up and down along the camera movement axis 46.

[0033] The fixed camera 6 is a fixed-focus camera fixedly mounted to the right side of the head unit 4. The fixed camera 6 captures images of various marks attached to the surface of the substrate P at the work position. FIG. 1 shows a pair of fiducial marks FM attached diagonally to the rectangular substrate P as an example of the marks. The fiducial marks FM are marks for detecting the amount of misalignment of the work position of the loaded substrate P relative to the origin coordinates. The positions of the fiducial marks FM are identified in the image data captured by the fixed camera 6, and the amount of misalignment relative to the origin coordinates is calculated. This amount of misalignment is referenced during component mounting, and components or component mounting jigs are mounted on the substrate P by the head 4H to prevent misalignment. The vertical movement range of the movable camera 5 may be expanded so that the movable camera 5 also captures the fiducial marks FM, thereby eliminating the fixed camera 6.

[0034] [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 unit 7 disposed on a base unit 10. The control unit 7 controls the operation of each unit of the component mounting apparatus 1, including the operation of the head unit 4 and various cameras. FIG. 3 also shows a Z-axis servo motor 43 and an R-axis servo motor 44, which are not shown in FIGS. 1 and 2. The Z-axis servo motor 43 and the R-axis servo motor 44 are motors incorporated into the head unit 4. The Z-axis servo motor 43 is a drive source that raises and lowers the head 4H (shaft 41) along the Z axis when picking up or mounting a component. The R-axis servo motor 44 is a drive source that rotates the shaft 41 around the R axis.

[0035] The control unit 7 is made up of a processor and the like that operates by loading a predetermined program, and functionally includes an imaging control unit 71, an image processing unit 72, an axis control unit 73, a main control unit 74, and a storage unit 75.

[0036] The imaging control unit 71 controls the imaging operations of the various cameras provided in the component mounting apparatus 1, in addition to the mobile camera 5, the fixed camera 6, and the component recognition camera 11. For example, the imaging control unit 71 provides these cameras with control signals that specify the timing at which they perform imaging operations and control signals that specify the exposure time.

[0037] The image processing unit 72 applies image processing techniques such as edge detection processing and pattern recognition processing involving feature extraction to image data acquired by the movable camera 5, fixed camera 6, component recognition camera 11, and the like, to extract various types of information from the images. Specifically, the image processing unit 72 performs processing to identify the positions of components mounted on the board P, marks affixed to jigs, component mounting positions, and the like, based on the image data acquired by the movable camera 5. The image processing unit 72 also performs processing to identify the positions of fiducial marks FM on the board P, based on the image data acquired by the fixed camera 6. Furthermore, the image processing unit 72 performs processing to identify the shape, position, and the like of the component held by the suction nozzle 42, based on the image data acquired by the component recognition camera 11.

[0038] The axis control unit 73 controls the movement of the head unit 4 in the X and Y directions by controlling the X-axis servo motor 26 and the Y-axis servo motor 28. The axis control unit 73 also controls the lifting and rotation of the head 4H (shaft 41) by controlling the Z-axis servo motor 43 and the R-axis servo motor 44 provided in the head unit 4. Furthermore, the axis control unit 73 controls the focusing operation of the moving camera 5 by moving in the Z direction along the side of the head unit 4 by controlling the camera movement motor 45.

[0039] The main control unit 74 comprehensively controls various operations of the component mounting apparatus 1. For example, the main control unit 74 provides control signals to the imaging control unit 71, the image processing unit 72, and the axis control unit 73 to perform operations such as capturing an image, performing image processing on image data, and driving the head unit 4 and the head 4H.

[0040] The storage unit 75 stores various setting values, parameters, control data, operation programs, etc. related to the component mounting apparatus 1. The storage unit 75 also stores various information related to the substrate P, the components to be mounted, and the jigs to be used. The information is, for example, information related to the size and height of the components and jigs, and the shape and color of the marks.

[0041] [Basic imaging operation of head unit] Before describing specific embodiments, the basic imaging operation of the head unit 4 will be described. FIG. 4 is a side view illustrating the imaging operation of a workpiece by the mobile camera 5 and fixed camera 6 mounted on the head unit 4. Note that the head 4H of the head unit 4 is omitted from FIG. 4. In FIG. 4, a substrate P supported on conveyors 21 and 22 is illustrated as an example of the imaging target. A fiducial mark FM (second characteristic portion) is provided on the top surface of the substrate P, and a high workpiece WA with a relatively thick workpiece thickness and a low workpiece WB with a relatively thin workpiece thickness are mounted on the top surface of the substrate P. A first mark MA and a second mark MB (first characteristic portion) are provided on the top surfaces of the high workpiece WA and the low workpiece WB, respectively.

[0042] The high workpiece WA and the low workpiece WB are mounted at predetermined positions on the substrate P by the head 4H, whose movement is controlled based on position information acquired by image recognition of the fiducial marks FM. In other words, even if the substrate P is carried in with a positional deviation on the conveyors 21 and 22, the high workpiece WA and the low workpiece WB as first workpieces are mounted at predetermined positions on the substrate P based on the position information of the fiducial marks FM.

[0043] The first mark MA and the second mark MB provide position information indicating the mounting position of a second workpiece (not shown) that is mounted on the substrate P after the high workpiece WA and the low workpiece WB have been mounted. That is, based on the position information acquired by image recognition of the first mark MA and the second mark MB, the head 4H mounts the second workpiece at a predetermined position on the substrate P. The second workpiece may be, for example, a component in which the high workpiece WA and the low workpiece WB are other components that are mounted on top of these components (first embodiment, described below). Alternatively, the high workpiece WA and the low workpiece WB are jigs that are mounted at positions determined by these jigs (second embodiment). Of course, multiple workpieces WA and WB may be the same height.

[0044] The mobile camera 5 and fixed camera 6 mounted on the head unit 4 are both fixed-focus cameras. The fixed camera 6 is attached to the head unit 4 at a position where it focuses on the top surface of the substrate P, that is, at a position where it focuses on the fiducial mark FM on the substrate P. The mobile camera 5 is attached to the head unit 4 so as to be movable in the Z direction. The mobile camera 5 can focus on both the first mark MA and the second mark MB, which are located at different heights.

[0045] First, the fixed camera 6 captures an image of the fiducial mark FM on the substrate P. The axis control unit 73 operates the X-axis servo motor 26 and the Y-axis servo motor 28 to move the head unit 4 so that the fixed camera 6 passes over the fiducial mark FM. The imaging control unit 71 causes the fixed camera 6 to perform an imaging operation at the timing when the fixed camera 6 passes over the fiducial mark FM.

[0046] The image processing unit 72 performs image processing to recognize the position of the fiducial mark FM in the image acquired by the fixed camera 6, and determines the XY coordinates of each part on the substrate P that has been carried in this time by the conveyors 21 and 22. If there is a difference between the determined XY coordinates and the reference XY coordinates, correction values ​​are derived to correct the difference. The axis control unit 73 moves the head unit 4 in the XY directions by referring to the correction values, and places the high workpiece WA or low workpiece WB that has been sucked onto the head 4H at a predetermined position on the substrate P.

[0047] Next, the first mark MA and the second mark MB are sequentially imaged by the moving camera 5. The axis control unit 73 acquires the Z position at which the moving camera 5 should be positioned when imaging each workpiece, for example by referring to the height information of the tall workpiece WA and the low workpiece WB stored in the memory unit 75. The axis control unit 73 controls the camera movement motor 45 to move the moving camera 5 to the Z position where it focuses on the first mark MA or the second mark MB.

[0048] In the example of FIG. 4, the mobile camera 5 is first moved to a Z position where it focuses on the second mark MB and captures an image. Then, while moving the head unit 4 in the XY directions, the mobile camera 5 is raised in the Z direction by the height difference h between the high workpiece WA and the low workpiece WB so that it focuses on the first mark MA. Once the Z movement of the mobile camera 5 by the height difference h is completed and the XY movement of the head unit 4 causes the mobile camera 5 to reach above the first mark MA, the mobile camera 5 performs an image capture operation. The image processing unit 72 performs image processing to recognize the positions of the first mark MA and the second mark MB in the image acquired by the mobile camera 5. The axis control unit 73 controls the head unit 4 based on the position information of the first mark MA and the second mark MB, and causes the head 4H to place the second workpiece at a predetermined position on the substrate P.

[0049] [First embodiment] 5(A) to 5(D) are side views showing a first embodiment of the present invention. In the first embodiment, an example is shown in which the first work and the second work are electronic components. More specifically, an example is shown in which second components C21 and C22 are mounted as second work on first components C11 and C12 as first work mounted on a substrate P. The first components C11 and C12 are relatively large electronic components such as packaged ICs. The second components C21 and C22 are electronic components mounted on the top surfaces of the first components C11 and C12.

[0050] As shown in FIG. 5A, when the substrate P is carried in by the substrate transport unit 2, the fixed camera 6 captures an image of the fiducial mark FM attached to the top surface of the substrate P. Based on the image recognition of the fiducial mark FM and the results of identifying the position information, any misalignment or distortion of the substrate P relative to its normal orientation on the substrate transport unit 2 is detected. The head 4H mounts the first components C11 and C12 in predetermined positions on the substrate P by referencing the designed mounting position coordinates of the first components C11 and C12 and a correction value derived based on the position information. A first mark M11 is attached to the top surface of the first component C11, which has a relatively small component thickness, and a second mark M12 is attached to the top surface of the first component C12, which has a relatively large component thickness. The first mark M11 and the second mark M12 correspond to the first characteristic feature of the claims, and the fiducial mark FM corresponds to the second characteristic feature.

[0051] As shown in FIG. 5B, when the first components C11 and C12 are mounted on the substrate P, the moving camera 5 sequentially captures images of the first mark M11 of the first component C11 and the second mark M12 of the first component C12. While horizontally moving the head unit 4, the axis control unit 73 controls the camera movement motor 45 to move the moving camera 5 vertically, focusing on the first mark M11 and the second mark M12, respectively, and capturing images. Based on the image recognition and positional information identification results of the first mark M11 and the second mark M12, predetermined positions on the substrate P where the second components C21 and C22 should be mounted are identified. In the first embodiment, the predetermined positions are predetermined positions on the top surfaces of the first components C11 and C12. For example, the second component C21 may be directly mounted at a predetermined position on the substrate based on the recognition results of the first mark M11.

[0052] 5(C) shows a state in which second components C21 and C22 are mounted on the upper surfaces of first components C11 and C12. According to this embodiment, the head 4H mounts the second components C21 and C22 based on the position information of marks M11 and M12 attached to the first components C11 and C12 to be mounted. This improves mounting accuracy compared to when the second components C21 and C22 are mounted using the fiducial marks FM on the substrate P as a reference.

[0053] 5(D) shows the state in which the movable camera 5 is imaging the top surfaces of the second components C21 and C22 as an inspection after mounting. Here, the movable camera 5 is also moved in the Z direction so as to focus on the top surfaces of the second components C21 and C22. Based on the image recognition of the top surfaces of the second components C21 and C22 acquired by the imaging, it is determined whether the second components C21 and C22 are mounted in the predetermined positions. This determination also refers to information on the positional deviation of the positions of the marks M11 and M12 from the fiducial mark FM.

[0054] [Second embodiment] 6(A) to 6(D) are diagrams showing the second embodiment, in which the substrate P held by the conveyors 21 and 22 is shown in a top view, and the head unit 4 is shown in a side view. In the first embodiment, an example is shown in which the first workpiece is a jig and the second workpiece is an electronic component to be mounted at a position defined by the jig.

[0055] 6(A) shows a state in which a first jig D1 and a second jig D2 are mounted on a substrate P. The first jig D1 and the second jig D2 are placed on the substrate P as jigs for assisting in mounting components on the substrate P. The first jig D1 has pockets H1 and H2 which are through openings for positioning components, and a mark M3 attached to its upper surface. Similarly, the second jig D2 has pockets H3 and H4 which are through openings for positioning components, and a mark M4 attached to its upper surface. The first jig D1 and the second jig D2 are mounted in predetermined positions on the substrate P by referring to the image recognition results of the fiducial marks FM.

[0056] As shown in FIG. 6(B), when the first jig D1 and the second jig D2 are placed on the substrate P, the movable camera 5 sequentially captures images of the mark M3 on the first jig D1 and the mark M4 on the second jig D2. While moving the head unit 4 horizontally, the axis control unit 73 controls the camera movement motor 45 to move the movable camera 5 up and down, focusing on the marks M3 and M4, respectively, and capturing images. Based on the position information obtained by image recognition of the marks M3 and M4, the amount of positional misalignment of the first jig D1 and the second jig D2 with respect to the substrate P is calculated. Because the positional relationship between the marks M3 and M4 and the pockets H1 to H4 is known, the actual positions of the pockets H1 to H4 are identified based on the amount of positional misalignment.

[0057] 6(C) shows a state in which components C31 and C32 are mounted on board P in pockets H1 and H2 of first jig D1, and components C33 and C34 are mounted on board P in pockets H3 and H4 of second jig D2. Because marks M3 and M4 attached to the top surfaces of jigs D1 and D2 are used as references rather than board P, the mounting accuracy of components C31 to C34 can be improved.

[0058] FIG. 6(D) shows the state in which the movable camera 5 is imaging the top surfaces of components C31-C34 as an inspection after mounting. Here, the movable camera 5 is also moved in the Z direction so as to focus on the top surfaces of components C31-C34, respectively. Based on the image recognition of the top surfaces of components C31-C34 acquired by the imaging, it is determined whether or not components C31-C34 are mounted in their respective predetermined positions. FIG. 6(D) shows an example in which the orientation of component C33 contained in pocket H3 is abnormal, while the orientations of the other components C31, C32, and C34 are normal. Then, first jig D1 and second jig D2 are removed from board P by head 4H.

[0059] [Third embodiment] In the third embodiment, when a plurality of first workpieces are mounted on the substrate P, an example is shown in which, after determining whether or not to move the mobile camera 5 up and down, images of the first characteristic portions present on the upper surfaces of each of the plurality of first workpieces are sequentially captured. FIG. 7 is a side view showing the third embodiment. Two first workpieces, a workpiece WC and a workpiece WD, are mounted on the substrate P. The workpiece WC is mounted at a first position P1 on the substrate P, and its upper surface is at a first height h1 relative to the substrate P. The workpiece WD is mounted at a second position P2 on the substrate P, and its upper surface is at a second height h2 relative to the substrate P. As the first characteristic portions, a mark MC is provided on the upper surface of the workpiece WC, and a mark MD is provided on the upper surface of the workpiece WD.

[0060] When the difference Δh between the first height h1 and the second height h2 is within a predetermined range, the main control unit 74 determines not to move the mobile camera 5 in the vertical direction. In this case, the axis control unit 73 moves the head unit 4 in the XY direction while fixing the Z position of the mobile camera 5. The axis control unit 73 causes the mobile camera 5 to pass over the mark MC at the first position P1 and the mark MD at the second position P2 in sequence to capture images. Note that the above phrase "the difference Δh is within a predetermined range" includes cases where the first height h1 and the second height h2 are the same height, as well as cases where the difference in height between h1 and h2 is within the depth of field of the mobile camera 5. Note that information on h1 and h2 is read from the memory unit 75.

[0061] According to the above embodiment, the marks MC and MD of the plurality of workpieces WC and WD are sequentially imaged, thereby improving the efficiency of the imaging operation by the mobile camera 5. In particular, the top surfaces of the workpieces WC and WD at the first position P1 and the second position P2 can be imaged without moving the mobile camera 5 in the vertical direction. Therefore, the efficiency of the imaging operation of the marks MC and MD by the mobile camera 5 can be improved.

[0062] On the other hand, when the difference Δh exceeds a predetermined range, the main control unit 74 determines to move the mobile camera 5 in the vertical direction. In other words, when the difference Δh is greater than the depth of field of the mobile camera 5, it is not possible to focus on both marks MC and MD with the Z position of the mobile camera 5 fixed, so the mobile camera 5 is moved up and down. In this case, the axis control unit 73 moves the mobile camera 5 in the Z direction to a position where it focuses on the mark MC of the workpiece WC at the first position P1 and takes an image. Next, the axis control unit 73 moves the head unit 4 in the XY directions to move the mobile camera 5 in the XY directions to the second position P2, and also moves the mobile camera 5 in the Z direction to a position where it focuses on the mark MD of the workpiece WD and takes an image.

[0063] 8A and 8B are side views showing another example of the third embodiment. Fig. 8 shows an example in which a determination as to whether to move the mobile camera 5 up and down is made at multiple Z positions. Two first components C13 and C14 are mounted on a substrate P. Marks M13 and M14 are respectively provided on the top surfaces of the first components C13 and C14, and second components C23 and C24 are mounted on the first components C13 and C14. The mobile camera 5 captures images for position recognition of the marks M13 and M14, and also captures images for position recognition of the top surfaces of the second components C23 and C24.

[0064] As shown in FIG. 8(A), if the Z positions of marks M13 and M14 both fall within the depth of field A1 of the mobile camera 5, the main control unit 74 determines not to move the mobile camera 5 in the Z direction. In this case, the axis control unit 73 moves the head unit 4 in the X and Y directions while keeping the Z position of the mobile camera 5 fixed. The axis control unit 73 moves the mobile camera 5 so that it passes sequentially over the marks M13 and M14 of the first parts C13 and C14, and captures images. On the other hand, if both marks M13 and M14 cannot fall within the depth of field A1, the axis control unit 73 moves the mobile camera 5 sequentially in the Z direction so that it focuses on the Z positions of marks M13 and M14, and captures images.

[0065] Next, the mobile camera 5 is raised to capture images of the upper surfaces of the second parts C23 and C24, as shown in FIG. 8(B). If the Z positions of the upper surfaces of the second parts C23 and C24 both fall within the depth of field A2 of the mobile camera 5, the main control unit 74 determines not to move the mobile camera 5 in the Z direction. In this case, the axis control unit 73 moves the head unit 4 in the X and Y directions while keeping the Z position of the mobile camera 5 fixed, causing it to pass sequentially above the upper surfaces of the second parts C23 and C24 and capture images. On the other hand, if the upper surfaces of the second parts C23 and C24 cannot both fall within the depth of field A2, the axis control unit 73 sequentially moves the mobile camera 5 in the Z direction to focus on each Z position of the upper surfaces of the second parts C23 and C24 and capture images.

[0066] FIG. 9 is a flowchart showing the control flow of the imaging operation by the head unit 4. Here, the control flow executed by the control unit 7 will be described with reference to the example in FIG. 7. The main control unit 74 controls the operation of the head unit 4, which is equipped with the mobile camera 5 and fixed camera 6, so as to sequentially image marks on the substrate P. The marks are the fiducial marks FM on the substrate P, the marks MC on the workpiece WC, or the marks MD on the workpiece WD, which are the first and second characteristic parts. Note that the imaging target is not limited to marks, and there are no particular restrictions as long as the features can be captured in the image by shape, color, etc.

[0067] The axis control unit 73 moves the head unit 4 in the XY directions to the position of the mark that is the imaging target (step S1). The main control unit 74 acquires information about the height of the mark that is the imaging target, i.e., the Z position of the mark, from the memory unit 75. The main control unit 74 determines whether or not the mark height is 0 (step S2). The mark height = 0 is the reference position in the Z direction, and in this case is the height of the top surface of the substrate P carried in by the substrate transport unit 2. In other words, the fiducial mark FM is located at the position where the mark height = 0.

[0068] If the mark height is 0 (YES in step S2), the main control unit 74 determines to have the fixed camera 6 capture an image of the mark. The axis control unit 73 moves the head unit 4 so that the fixed camera 6 passes above the fiducial mark FM. The imaging control unit 71 causes the fixed camera 6 to perform an imaging operation at the timing of the passing (step S3).

[0069] If the mark height is not 0 (NO in step S2), the main control unit 74 determines that the mark should be imaged by the moving camera 5. In the example of Fig. 7, the case where the mark to be imaged is mark MC of workpiece WC or mark MD of workpiece WD is the case when the mark to be imaged is. The main control unit 74 determines whether the mark height of the imaged target is at the Z position where the moving camera 5 is focused (step S4).

[0070] If the mobile camera 5 is not at the Z position where it will be focused (NO in step S4), the axis control unit 73 operates the camera movement motor 45 to move the mobile camera 5 to the Z position where it will be focused (step S5). After the movement, the imaging control unit 71 causes the mobile camera 5 to perform an imaging operation (step S6). On the other hand, if the mobile camera 5 is at the Z position where it will be focused (YES in step S4), step S5 is skipped, and the mobile camera 5 is caused to perform an imaging operation without moving the mobile camera 5 in the Z direction.

[0071] After executing step S3 or step S6, the main control unit 74 determines whether or not the necessary mark imaging has been completed for one substrate P carried in by the substrate transport unit 2 (step S7). If imaging is incomplete (NO in step S7), the process returns to step S1 and is repeated. If imaging is complete (YES in step S7), the process ends. When a new substrate P is carried in by the substrate transport unit 2, the process from step S1 onwards is repeated.

[0072] 10 is a side view showing an example in which imaging by the mobile camera 5 and the fixed camera 6 is performed in one movement cycle of the head unit 4. Two first components C15 and C16 are mounted on a board P carried in by the board transport section 2. A mark M15 is provided on the top surface of one of the first components C15, and a second component C25 is mounted on the top surface of the board P. The fixed camera 6 is responsible for imaging an area A3 on the top surface of the board P that includes the fiducial mark FM. The mobile camera 5 is responsible for imaging an area A4 on the top surface of the first component C15 that includes the mark M15, and an area A5 that includes the top surfaces of the first component C16 and the second component C25.

[0073] Simply put, imaging of areas A3, A4, and A5 may be performed sequentially during three cycles of movement of the head unit 4 over the substrate P. However, to improve takt time, it is desirable to perform imaging by the mobile camera 5 and the fixed camera 6 within one movement cycle of the head unit 4. For example, when the fixed camera 6 images area A3, the mobile camera 5 is moved to a Z position focused on area A4. Then, during the first cycle of movement of the head unit 4, imaging of area A3 by the fixed camera 6 and imaging of area A4 by the mobile camera 5 are performed. In other words, imaging of the fiducial mark FM and imaging of the mark M15 are performed during one movement cycle of the head unit 4. Then, the mobile camera 5 is moved to a Z position focused on area A5, and during the second cycle of movement of the head unit 4, imaging of the top surfaces of the first component C16 and the second component C25 is performed. According to this embodiment, the necessary imaging can be completed within two movement cycles of the head unit 4, improving takt time. [Explanation of symbols]

[0074] 1. Component mounting device (workpiece mounting device) 4 Head Unit 4H head 5. Moving camera (first camera) 6 Fixed camera (second camera) 7 Control Unit P board C11, C12 First part (first work) C21, C22 2nd part (2nd work) C31, C32, C33, C34 parts (second work) D1, D2 1st jig, 2nd jig (1st workpiece) FM Fiducial Mark FM (second characteristic part) M11, M12 1st mark, 2nd mark (1st characteristic part) M3, M4, MA, MB, MC, MD mark (first characteristic part) P1, P2 1st position, 2nd position WA, WB High work, low work (first work) WC Work (1st work) h1, h2 First height, second height

Claims

1. a head unit including a head that mounts a workpiece on a substrate; a first camera mounted on the head unit; a control unit that controls operations of the head unit and the first camera, The control unit focusing the first camera on a first feature portion present on the top surface of the first workpiece mounted on the substrate to capture an image; a workpiece mounting device that causes the head to mount a second workpiece at a predetermined position on the substrate based on position information of the first feature portion obtained by the imaging;

2. The workpiece mounting device according to claim 1, the first workpiece is a first component to be mounted on a substrate, The second workpiece is a second component that is mounted on the first component.

3. The workpiece mounting device according to claim 1, the first camera is a mobile camera mounted on the head unit so as to be movable up and down, The control unit moves the moving camera up and down to focus on the first characteristic portion.

4. The workpiece mounting device according to any one of claims 1 to 3, a second camera fixedly attached to the head unit and whose operation is controlled by the control unit; The control unit causing the second camera to capture an image of a second feature portion present on the top surface of the substrate; a workpiece mounting device that causes the head to mount the first workpiece at a predetermined position on the substrate based on position information of the second feature portion obtained by the imaging;

5. The workpiece mounting device according to any one of claims 1 to 3, When a plurality of the first workpieces are mounted on the substrate, The control unit causes the first camera to sequentially capture images of the first feature portions present on the top surfaces of the plurality of first workpieces.

6. The workpiece mounting device according to claim 3, When the first workpiece is mounted at least at a first position and a second position on the substrate, and the height of the top surface of the first workpiece at the first position is a first height, and the height of the top surface of the first workpiece at the second position is a second height, The control unit, when the difference between the first height and the second height is within a predetermined range, sequentially captures images of the first characteristic portion present on the top surface of the first workpiece at the first position and the second position without moving the mobile camera in the vertical direction.

7. The workpiece mounting device according to claim 3, When the first workpiece is mounted at least at a first position and a second position on the substrate, and the height of the top surface of the first workpiece at the first position is a first height, and the height of the top surface of the first workpiece at the second position is a second height, When the difference between the first height and the second height exceeds a predetermined range, the control unit causes the moving camera to capture an image of the first characteristic portion present on the top surface of the first workpiece at the first position, and after moving the moving camera in the vertical direction, causes the moving camera to capture an image of the first characteristic portion present on the top surface of the first workpiece at the second position.

Images