Component Mounting Equipment

Abstract

To provide a component mounting device capable of detecting the absolute rotational position of a rotating body with a simple configuration.SOLUTION: The component mounting device includes: a background member B that is provided to a rotating body 11 that holds multiple shafts at equal intervals on the circumference centered on the rotation axis CL, which has a feature part F for identifying a specific shaft (the shaft to which nozzle 13(1) is attached) at a position included in an imaging field of view A of camera for picking up components held by nozzles 13(1) to 13(12) on a component recognition station ST7; a feature recognition unit that recognizes the feature part F with a camera; and a nozzle shaft position identification unit that identifies the stations ST1 to ST12 where multiple shafts are located, on the basis of the rotation position when the feature recognition unit detected the feature part F.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a component mounting apparatus that mounts components on a board while holding them under negative pressure. [Background technology]

[0002] A component mounting device that mounts components on a circuit board uses a work head equipped with a nozzle that holds the components by utilizing suction force generated by a negative pressure source to pick up components from a component supply unit and place them on a circuit board. A known type of this work head is a rotary type that has multiple shafts, each with a nozzle attached to its lower end, arranged at equal intervals on a rotating body that rotates indexwise (see, for example, Patent Document 1).

[0003] The mounting head (working head) described in Patent Document 1 has multiple nozzle stop stations with different functions arranged at positions where the nozzle stops as the rotor rotates indexwise. For example, at the work station, the nozzle is raised and lowered to hold a component on the nozzle, and the held component is then mounted on a board. In addition, the component detection station detects whether or not a component is held on the nozzle. In addition, the component recognition station takes an image of the component held by the nozzle. With a rotary-type working head, component mounting can be carried out efficiently by simultaneously performing each task at each station while the rotor rotates indexwise. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-133438 Summary of the Invention [Problem to be solved by the invention]

[0005] In order for a rotary work head to properly perform work at each station, the component mounting device must recognize and store the absolute rotational position of the rotating body. Therefore, prior art, including Patent Document 1, includes an absolute encoder that detects the absolute rotational position of the motor that rotates the rotating body, and a light-shielding sensor that detects a specific pin. However, when an absolute encoder or a light-shielding sensor is installed on the work head, the weight of the absolute encoder battery, mounting brackets for the sensor, etc., increases the weight of the work head, which moves at high speed within a horizontal plane. This causes problems such as vibrations as the work head moves and reduced accuracy of the stopping position.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a component mounting device that can detect the absolute rotational position of a rotating body with a simple configuration. [Means for solving the problem]

[0007] a component recognition unit that recognizes the position or state of the component based on the image captured by the camera; a background member that is provided on the rotor and has a feature that is located within the imaging field of the camera and that identifies a specific shaft among the multiple shafts; a feature recognition unit that recognizes the feature using the camera; and a nozzle shaft position identification unit that identifies the station at which the multiple shafts are located based on the rotational position when the feature recognition unit detects the feature. [Effects of the Invention]

[0008] According to the present invention, the absolute rotational position of a rotating body can be detected with a simple configuration. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing the overall configuration of a component mounting apparatus according to an embodiment of the present invention; [Figure 2] FIG. 1 is a diagram illustrating the configuration of a main part of a work head provided in a component mounting apparatus according to an embodiment of the present invention; [Figure 3] FIG. 1 is a diagram illustrating the configuration of a camera of a work head provided in a component mounting apparatus according to an embodiment of the present invention; [Figure 4] 1 is a bottom view of a main part of a work head provided in a component mounting apparatus according to an embodiment of the present invention; [Figure 5] FIG. 1A is a diagram showing a state in which a nozzle having a characteristic portion is positioned in the imaging field of view of a camera of a work head provided in a component mounting apparatus according to an embodiment of the present invention; FIG. 1B is a diagram showing a state in which a nozzle having no characteristic portion is positioned in the imaging field of view of a work head camera of the component mounting apparatus according to an embodiment of the present invention; [Figure 6] FIG. 1 is a block diagram showing the configuration of a control system of a component mounting apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Next, an embodiment of the present invention will be described with reference to the drawings. First, the structure of a component mounting apparatus 1 will be described with reference to Fig. 1. Hereinafter, the substrate transport direction is defined as the X-axis direction, the direction perpendicular to the X-axis direction in a horizontal plane is defined as the Y-axis direction, the direction perpendicular to the XY plane is defined as the Z-axis direction, and the direction in a horizontal plane rotating around the Z-axis direction as an axis is defined as the θ direction.

[0011] 1, component mounting apparatus 1 has the function of applying negative pressure to the nozzle opening of a nozzle to hold components by vacuum suction and mount them on a board. A board transport mechanism 2 equipped with a pair of transport conveyors extending along the X-axis is located in the center of base 1a. Board transport mechanism 2 receives and transports board 3, the target for component mounting, from an upstream device, and positions and holds it at a mounting operation position by the component mounting mechanism, which will be described below.

[0012] Component supply units 4 are arranged on both sides of the board transport mechanism 2. The component supply unit 4 is configured by arranging multiple tape feeders 5 in parallel along the X-axis on a feeder table 4a. The tape feeders 5 feed the carrier tape containing the components to be mounted on the board 3 at a pitch rate, thereby supplying the components to be mounted to a position where they will be picked up by the work head 8 of the component mounting mechanism.

[0013] Next, the component mounting mechanism will be described. In Fig. 1, a Y-axis table 6 equipped with a linear drive mechanism is disposed at the end of the base 1a in the X-axis direction. A beam 7 equipped with a linear drive mechanism 7a (see Fig. 2) is attached to the Y-axis table 6 so as to be movable along the Y-axis. A main body frame 9 of a work head 8 is attached to the beam 7 so as to be movable along the X-axis.

[0014] The work head 8 has the function of picking up and holding components to be mounted on the board 3 from the component supply unit 4 using a nozzle 13 (see FIG. 2). The nozzle 13 holds the components by applying negative pressure generated by a negative pressure source to the nozzle opening at the tip. The work head 8 moves horizontally in the X and Y axes by driving the Y-axis table 6 and beam 7, and mounts the components held by the nozzle 13 onto the board 3, which is positioned and held by the board transport mechanism 2. In other words, the Y-axis table 6 and beam 7 constitute an XY movement unit 18 (see FIG. 6) that moves the work head 8 in the X and Y axes. Each unit of the component mounting device 1 is controlled by a control device C provided in the component mounting device 1.

[0015] Next, the structure of the main parts of the work head 8 will be described with reference to Figure 2. A rotor holder 10 is provided extending horizontally below the main body frame 9 of the work head 8. A rotor 11 is held by the rotor holder 10 so that it can rotate freely around a rotation axis CL in the Z-axis direction. A plurality of shafts 12 (12 in this example) are held at equal intervals on the circumference of the rotor 11, centered on the rotation axis CL, so that they can be raised and lowered. A nozzle 13 for holding a part is attached to the lower end of each shaft 12.

[0016] A rotating shaft 14 is connected to the upper part of the rotating body 11. The rotating shaft 14 is rotated about a rotation axis CL by a rotor drive unit 15 fixed to the main body frame 9. The control device C controls the rotor drive unit 15 to drive and rotate the rotating shaft 14, causing the rotating body 11 to rotate in the θ direction about the rotation axis CL. As the rotating body 11 rotates, the multiple shafts 12 move in circles about the rotation axis CL. A substantially disk-shaped background member B is arranged below the rotating body 11 at a height position higher than the nozzles 13 attached to the shafts 12.

[0017] In Fig. 2, the rotor drive unit 15 is equipped with an encoder 16 that detects the rotation angle of the rotor 11 that is driven to rotate by the rotor drive unit 15. The encoder 16 is, for example, an incremental rotary encoder. The rotor drive unit 15 rotates the rotor 11 to position the multiple shafts 12 in order at multiple (12 in this example) stations ST1 to ST12 (see Fig. 4) set in the work head 8. A shaft lifting unit 17 is fixedly disposed on the main body frame 9 and lifts and lowers the shaft 12 that is stopped at work station ST1 of the multiple stations ST1 to ST12.

[0018] 2 and 3, a camera 20 is fixedly disposed on rotor holding section 10 to capture images of components held by nozzles 13 at component recognition station ST7 (a specific station) among multiple stations ST1 to ST12. Camera 20 extends downward on the side of rotor holding section 10 and includes a light guide tube 21 that extends horizontally toward below nozzle 13 stopped at component recognition station ST7. Inside light guide tube 21, an imaging element 22 with its optical axis facing downward is disposed in the downward extending portion.

[0019] A camera opening 23 is formed on the upper surface of the horizontally extending portion of the light guide tube 21, below the nozzle 13 stopped at the component recognition station ST7. A plurality of mirrors 24 are arranged inside the light guide tube 21, which guide an image of the nozzle 13 stopped at the component recognition station ST7 to the image pickup element 22 through the camera opening 23. An illumination unit 25, such as an LED, is arranged around the camera opening 23 of the light guide tube 21 to illuminate the area above, including the nozzle 13 and part of the background member B, which are to be imaged.

[0020] In this way, the rotating body 11 holds multiple shafts 12 at equal intervals on a circumference centered on the rotation axis CL, and rotates around the rotation axis CL to sequentially position the multiple shafts 12 at multiple stations ST1 to ST12. The control device C then controls the shaft lifting unit 17 to raise and lower the shaft 12 stopped at the work station ST1. This raises and lowers the nozzle 13 attached to the shaft 12. The control device C also controls the imaging element 22 and lighting unit 25 of the camera 20 to capture an image of the nozzle 13 stopped at the component recognition station ST7 from below.

[0021] 2 and 3, a background member B is attached to the underside of the rotating body 11. Next, a detailed configuration of the background member B will be described with reference to FIGS. 4 and 5. In FIG. 4, the background member B is substantially circular with its center at the rotation axis CL, and is sized so that a portion of the nozzle 13 attached to the shaft 12 overlaps with a portion of the outer periphery of the background member B when viewed from below. The background member B is made of a material with a reflectance significantly different from that of the nozzle 13. In this example, the nozzle 13 is made of a material with a high reflectance, and the background member B is made of a material with a low reflectance (blackish).

[0022] 4 shows a state in which nozzle 13(1), one of the twelve nozzles 13(1) to 13(12), is stopped at component recognition station ST7 (a specific station). In addition to nozzle 13(1), a portion of background member B is included in the imaging field A of camera 20. A characteristic portion F is provided on background member B at the position of nozzle 13(1) to distinguish it from the other nozzles 13(2) to 13(12). In this example, the characteristic portion F is formed by cutting out a portion of background member B, including the portion that overlaps with nozzle 13(1) when viewed from below.

[0023] FIG. 5(a) shows a captured image 26 taken by camera 20 of nozzle 13(1) stopped at component recognition station ST7. FIG. 5(b) shows a captured image 26 taken by camera 20 of nozzle 13(2) stopped at component recognition station ST7. In captured image 26 of nozzle 13(1), a part of background member B and a characteristic portion F formed by cutting out background member B are visible. On the other hand, the background member B visible in captured image 26 of nozzle 13(2) does not have the characteristic portion F, making it possible to distinguish it from nozzle 13(1). Similarly, the background member B visible in captured images 26 of nozzles 13(3) to 13(12) also does not have the characteristic portion F.

[0024] In this way, the work head 8 is provided on the rotating body 11, and is provided with a background member B that is provided with a characteristic portion F for identifying a specific shaft (the shaft 12 to which the nozzle 13(1) is attached) among the multiple shafts 12, at a position included in the imaging field A of the camera 20. The background member B also has a non-characteristic portion CF (FIG. 5(b)) that is on a circumference that overlaps with the characteristic portion F centered on the rotation axis CL and is included in the imaging field A together with the nozzles 13(2) to 13(12) of the shafts other than the specific shaft.

[0025] Next, the configuration of the control system of the component mounting apparatus 1 will be described with reference to Fig. 6. The control device C provided in the component mounting apparatus 1 includes a component mounting operation execution unit 30 which is an arithmetic processing unit equipped with a CPU or the like, a rotational position detection unit 31, an image recognition unit 32, a nozzle shaft position identification unit 33, a nozzle shaft position storage unit 34 which is a storage unit, and an operation program storage unit 35. The rotational position detection unit 31 detects the relative rotational position of the rotating body 11 based on the detection signal of the encoder 16.

[0026] Image recognition unit 32 recognizes the position or state of the components based on the images captured by camera 20. Image recognition unit 32 includes, as internal processing units, a component recognition unit 32a and a feature recognition unit 32b. Component recognition unit 32a recognizes and processes captured images 26 of nozzles 13(1) to 13(12) sequentially stopped at component recognition station ST7, taken by camera 20, to recognize the state of each of the components held by nozzles 13(1) to 13(12).

[0027] 6, the characteristic part recognition unit 32b performs recognition processing on the captured image 26 taken by the camera 20 of the nozzles 13(1) to 13(12) that have been sequentially stopped at the component recognition station ST7, to detect the characteristic part F of the background member B. For example, the characteristic part recognition unit 32b horizontally scans the position (detection line SL) where the camera 20 includes the characteristic part F or the non-characteristic part CF, and recognizes that there is a characteristic part F if a bright part is detected, and recognizes that there is no characteristic part F (there is a non-characteristic part CF) if there is no bright part detected.

[0028] That is, the characteristic part recognition unit 32b recognizes the characteristic part F by utilizing the difference in brightness between the non-characteristic part CF and the characteristic part F. In this way, the characteristic part recognition unit 32b recognizes the characteristic part F using the camera 20. Note that when the characteristic part recognition unit 32b recognizes the presence or absence of the characteristic part F, the camera 20 may be configured to scan only the detection line SL in one dimension. By having the camera 20 scan only the detection line SL and having the feature part recognition unit 32b recognize the presence or absence of the characteristic part F, it is possible to detect the nozzle 13(1) having the characteristic part F in a short period of time.

[0029] The nozzle shaft position identifying unit 33 identifies stations ST1 to ST12 at which the multiple shafts 12 are located, based on the rotational position when the characteristic part recognition unit 32b detects the characteristic part F. Specifically, the nozzle shaft position identifying unit 33 controls the rotor driving unit 15 to sequentially stop the nozzles 13(1) to 13(12) at the component recognition station ST7. When the characteristic part recognition unit 32b detects the characteristic part F, the nozzle shaft position identifying unit 33 determines that the nozzle 13(1) is stopped at the component recognition station ST7. Then, the nozzle shaft position identifying unit 33 stores the rotational position of the rotating body 11 detected by the rotational position detection unit 31 at that time in the nozzle shaft position memory unit 34.

[0030] The nozzle shaft position identifying unit 33 detects a specific shaft 12 (a shaft 12 to which a nozzle 13(1) is attached) immediately after powering on the component mounting apparatus 1, for example. Once the nozzle shaft position identifying unit 33 detects a specific shaft 12, it thereafter identifies stations ST1 to ST12 at which multiple shafts 12 are located, based on the rotation angle stored in the nozzle shaft position memory unit 34 and the relative rotation position of the rotating body 11 detected by the rotation position detection unit 31.

[0031] 6, the component mounting operation execution unit 30 operates the operation head 8 to perform a component mounting operation to mount components on the board 3, based on the operation program stored in the operation program storage unit 35 and the rotational positions of the multiple shafts 12 (or nozzles 13(1) to 13(12)) identified by the nozzle shaft position identification unit 33. At that time, the component mounting operation execution unit 30 corrects the mounting position of the component on the board 3 based on the state of the component held by the nozzles 13(1) to 13(12) recognized by the component recognition unit 32a (presence or absence of the component, amount of deviation from the nozzle).

[0032] As described above, the component mounting apparatus 1 of this embodiment includes a plurality of shafts 12 having nozzles 13(1) to 13(12) at their lower ends, a rotating body 11 that holds the plurality of shafts 12 at equal intervals on a circumference centered on a rotation axis CL and positions them sequentially at a plurality of stations ST1 to ST12, a rotational position detection unit 31 that relatively detects the rotational position of the rotating body 11, a camera 20 that photographs components held by the nozzles 13(1) to 13(12) at a specific station (component recognition station ST7), and a component recognition unit 32a that recognizes the position or state of the components based on the image captured by the camera 20.

[0033] Furthermore, the component mounting device 1 is provided with a background member B that is provided on the rotating body 11 and has a feature F at a position included in the imaging field of view A of the camera 20 for identifying a specific shaft 12 (a shaft 12 to which a nozzle 13(1) is attached), a feature recognition unit 32b that recognizes the feature F with the camera 20, and a nozzle shaft position identification unit 33 that identifies stations ST1 to ST12 at which multiple shafts 12 are located based on the rotational position when the feature recognition unit 32b detects the feature F.

[0034] In this way, the component mounting apparatus 1 of this embodiment detects the positions of the multiple shafts 12 using the encoder 16 that detects the relative rotational position of the rotating body 11 and the camera 20 that photographs the components held by the nozzle 13 during the component mounting operation. This makes it possible to detect the absolute rotational position of the rotating body 11 with a simple configuration. [Industrial Applicability]

[0035] The component mounting device of the present invention has the effect of being able to detect the absolute rotational position of a rotating body with a simple configuration, and is useful in the field of mounting components onto a board. [Explanation of symbols]

[0036] 1. Component mounting equipment 3. Circuit Board 8 working head 9 Main frame 11 Rotating body 12 shafts 13, 13(1)~13(12) Nozzle 20 Camera A. Imaging field of view B. Background material CF non-feature part F. Feature Stations ST1 to ST12 ST7 Part Recognition Station (Specific Station)

Claims

1. A component mounting device that holds a component with a nozzle and mounts it on a board, a plurality of shafts each having the nozzle at a lower end thereof; a rotating body that holds the plurality of shafts at equal intervals on a circumference centered on a rotation axis and rotates about the rotation axis to sequentially position the plurality of shafts at a plurality of stations; a rotational position detection unit that relatively detects the rotational position of the rotating body; a camera that photographs a component held by the nozzle at a specific station among the plurality of stations; a component recognition unit that recognizes the position or state of a component based on the image captured by the camera; a background member provided on the rotating body, the background member being located at a position included in the imaging field of the camera and having a feature portion for identifying a specific shaft among the plurality of shafts; a feature recognition unit that recognizes the feature using the camera; a nozzle shaft position specifying unit that specifies a station at which the plurality of shafts are located based on the rotational position when the feature recognition unit detects the feature.

2. the background member has a non-feature portion that is on a circumference that overlaps with the feature portion and is centered on the rotation axis and is included in the imaging field of view together with a nozzle of a shaft other than the specific shaft, The component mounting device according to claim 1 , wherein the characteristic portion recognition unit recognizes the characteristic portion by utilizing a difference in brightness between the non-characteristic portion and the characteristic portion.

3. 3. The component mounting device according to claim 1, wherein the background member is attached to a lower surface of the rotating body.

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