JP7680341B2 - Component Mounting Machine - Google Patents

Description

The present invention relates to a component mounter that mounts electronic components onto a substrate.

A component mounter for mounting electronic components on a substrate such as a printed wiring board is equipped with a holding nozzle having a holding surface for holding the electronic components, and a head unit that performs a component mounting operation to mount the electronic components held on the holding surface onto the substrate. When the head unit performs the component mounting operation, a component image is captured based on light reflected from the electronic components held on the holding surface of the holding nozzle, and image recognition of the electronic components is performed based on the component image.

The component image may contain not only a component image area corresponding to the electronic component, but also a holding surface image area corresponding to the holding surface of the holding nozzle. In this case, in order to accurately recognize the electronic component using the component image, it is necessary to increase the contrast between the component image area and the holding surface image area in the component image.

Patent document 1 discloses a technique in which a first polarizing filter and a second polarizing filter are arranged in series with each other on the optical path between the light source and the imaging device. In this technique, the first polarizing filter and the second polarizing filter are rotatable around the optical axis.

JP 2003-46297 A

In the technology disclosed in Patent Document 1, polarized light that has passed through a first polarizing filter is irradiated onto an electronic component, and polarized light that has been reflected by the electronic component in response to the irradiation of the polarized light and passed through a second polarizing filter is received by an imaging device. This technology focuses on the fact that the electrodes of the electronic component have the property of specularly reflecting light, and that the background forming plate that forms the background of the electronic component has the property of diffusely reflecting light. In other words, polarized light that has been specularly reflected by the electronic component in response to the irradiation of polarized light that has passed through the first polarizing filter passes through the second polarizing filter, while non-polarized light that has been diffusely reflected by the background forming plate is restricted from passing through the second polarizing filter. In this way, the difference in the light reflection characteristics of the electronic component and the background forming plate is utilized to increase the contrast of the component image area in the image based on the light received by the imaging device.

However, depending on the type of electronic component, the light reflection characteristics may not be those of specular reflection, but rather those of diffuse reflection. In this case, the non-polarized light diffusely reflected by the electronic component is restricted from passing through the second polarizing filter, just as with the background forming plate, so there is a risk that the contrast of the component image area in the image captured by the imaging device cannot be increased. In other words, the technology disclosed in Patent Document 1 may not be able to obtain an image with high contrast between the component image area and its surrounding area. Therefore, the technology disclosed in Patent Document 1 may not be able to accurately recognize the image of the electronic component held by the holding surface of the holding nozzle.

The object of the present invention is to provide a component mounter that can accurately perform image recognition of electronic components held on the holding surface of a holding nozzle.

A component mounter according to one aspect of the present invention includes a head unit to which a holding nozzle having a holding surface for holding an electronic component is attached, and which performs a component mounting operation to mount the electronic component held on the holding surface onto a board; a light irradiation unit that irradiates the electronic component held on the holding surface with unpolarized light; and an image acquisition unit that acquires a component image based on light reflected by the electronic component in response to the incidence of the unpolarized light. The holding surface has a characteristic of reflecting polarized light in a specific direction when the unpolarized light is incident on it. The image acquisition unit includes a polarizing unit that restricts the transmission of holding surface reflected polarized light, which is polarized light reflected by the holding surface, and an imaging unit that generates the component image by receiving light that has passed through the polarizing unit.

According to this component mounting machine, the holding surface of the holding nozzle that holds the electronic component has the property of reflecting polarized light in a specific direction when non-polarized light irradiated from the light irradiation unit is incident on the holding surface. In this case, the light reflected by the holding surface in response to the incidence of non-polarized light becomes holding surface reflected polarized light, which is polarized in a specific direction. On the other hand, there are electronic components that have the reflection characteristic of specular reflection and those that have the reflection characteristic of diffuse reflection. For example, an electronic component that has a metal electrode exposed on the underside opposite to the side that abuts on the holding surface has the reflection characteristic of specular reflection, and an electronic component that does not have an exposed electrode has the reflection characteristic of diffuse reflection. When non-polarized light irradiated from the light irradiation unit is incident on an electronic component, the reflected light from the electronic component becomes non-polarized light, regardless of whether the electronic component has the reflection characteristic of specular reflection or diffuse reflection.

The image acquisition unit that acquires a component image corresponding to an electronic component held on the holding surface of the holding nozzle includes a polarizing unit and an imaging unit. The polarizing unit restricts the transmission of polarized light reflected from the holding surface in response to the incidence of non-polarized light. On the other hand, the light reflected from the electronic component in response to the incidence of non-polarized light is non-polarized light, so the reflected light from this electronic component passes through the polarizing unit. The imaging unit generates a component image by receiving the light that has passed through the polarizing unit. Since the transmission of the polarized light reflected from the holding surface that is reflected by the holding surface is restricted, and the non-polarized light reflected from the electronic component passes through the polarizing unit, the component image is an image in which the contrast between the component image area corresponding to the electronic component and the holding surface image area corresponding to the holding surface is enhanced. Therefore, it is possible to accurately recognize the electronic component held on the holding surface of the holding nozzle based on the component image acquired by the image acquisition unit.

The component mounter may further include an image recognition unit that performs image recognition of the electronic component held on the holding surface based on the component image acquired by the image acquisition unit, and a head control unit that controls the component mounting operation of the head unit based on the recognition result by the image recognition unit.

In this embodiment, the image recognition unit performs image recognition of the electronic component held on the holding surface of the holding nozzle based on the component image acquired by the image acquisition unit. The head control unit controls the component mounting operation of the head unit based on the recognition result by the image recognition unit. The component mounting operation of the head unit, which is controlled based on the recognition result by the image recognition unit, improves the mounting accuracy of the electronic component on the board.

In the above-mentioned component mounting machine, the image acquisition unit is a camera in which an image sensor constituting the image capturing unit and a polarizing filter constituting the polarizing unit are arranged side by side on an optical axis, the polarizing filter is rotatable around the optical axis, and the holding nozzle is rotatable around an axis.

In this embodiment, the polarizing filter constituting the polarizing section of the image acquisition section can rotate around the optical axis, and the holding nozzle can rotate around the axis. In this case, by adjusting the rotation angle of at least one of the polarizing filter and the holding nozzle, it is possible to adjust the degree to which the holding surface-reflected polarized light reflected by the holding surface of the holding nozzle is restricted from passing through the polarizing filter.

The component mounter may further include an imaging control unit that rotates at least one of the polarizing filter and the holding nozzle at a specific rotation angle from a predetermined reference position so that the polarizing filter can regulate the transmission of the polarized light reflected by the holding surface, and then causes the image acquisition unit to acquire the component image.

In this aspect, the imaging control unit rotates at least one of the polarizing filter and the holding nozzle by a specific rotation angle before the image acquisition unit acquires a component image so that the transmission of polarized light reflected by the holding surface at the polarizing filter can be restricted. This makes it possible to more reliably restrict the transmission of polarized light reflected by the holding surface of the holding nozzle through the polarizing filter. Therefore, the component image acquired by the image acquisition unit is an image in which the contrast between the component image area and the holding surface image area is more reliably enhanced. Therefore, it becomes possible to more accurately recognize the image of the electronic component held on the holding surface of the holding nozzle based on the component image acquired by the image acquisition unit.

In the above component mounter, the imaging control unit performs a test image acquisition process in which, before causing the image acquisition unit to acquire the component image, the imaging control unit rotates at least one of the polarizing filter and the holding nozzle by a predetermined rotation angle and causes the image acquisition unit to acquire a plurality of test images for each of the rotation angles, and a setting process in which the test image with the highest contrast value is identified from the plurality of test images and the rotation angle corresponding to the identified test image is set as the specific rotation angle.

In this aspect, the imaging control unit performs a test image acquisition process and a setting process before causing the image acquisition unit to acquire a component image. In the test image acquisition process, the imaging control unit rotates at least one of the polarizing filter and the holding nozzle by a predetermined rotation angle, and causes the image acquisition unit to acquire multiple test images for each rotation angle. In the setting process, the imaging control unit identifies the test image with the highest contrast value from among the multiple test images, and can set the rotation angle corresponding to the identified test image as the specific rotation angle when causing the image acquisition unit to acquire a component image.

In the above component mounter, the electronic components include multiple types of components classified according to differences in shape, and the holding nozzle includes multiple types of nozzles that are classified according to the types of electronic components and have different polarization directions of the holding surface reflected polarized light on the holding surface. In this case, the specific rotation angle is set for each type of holding nozzle.

In this aspect, the holding nozzle has multiple types of nozzles with different polarization directions of the polarized light reflected by the holding surface on the holding surface. In this case, the specific rotation angle when the imaging control unit causes the image acquisition unit to acquire a component image is set for each type of holding nozzle. The imaging control unit rotates at least one of the polarizing filter and the holding nozzle by the specific rotation angle for each type of holding nozzle. This makes it possible to restrict the polarized light reflected by the holding surface of the holding nozzle from passing through the polarizing filter in multiple types of holding nozzles. As a result, the component images acquired by the image acquisition unit corresponding to each of the multiple types of holding nozzles are images with enhanced contrast between the component image area and the holding surface image area.

The component mounter may further include a management data storage unit that stores management data including component information for identifying the type of electronic component and nozzle information for identifying the type of holding nozzle. In this case, the management data storage unit stores the management data in association with the specific rotation angle for each type of holding nozzle. The imaging control unit then rotates at least one of the polarizing filter and the holding nozzle based on the specific rotation angle associated with the management data, and then causes the image acquisition unit to acquire the component image. The head control unit also controls the component mounting operation of the head unit based on the management data.

In this aspect, when rotating at least one of the polarizing filter and the holding nozzle, the imaging control unit can refer to the specific rotation angle for each type of holding nozzle associated with the management data stored in the management data storage unit. In this case, the imaging control unit rotates at least one of the polarizing filter and the holding nozzle based on the specific rotation angle associated with the management data, and then causes the image acquisition unit to acquire a component image.

In the above component mounting machine, when the head unit equipped with multiple holding nozzles of the same type performs the component mounting operation, the imaging control unit stops the multiple holding nozzles at a predetermined reference position and rotates the polarizing filter at the specific rotation angle, and then causes the image acquisition unit to acquire the component image.

In this aspect, when a head unit equipped with multiple holding nozzles of the same type performs a component mounting operation, the imaging control unit stops the multiple holding nozzles at a predetermined reference position and rotates the polarizing filter at a specific rotation angle that can regulate the transmission of polarized light reflected from the holding surface before causing the image acquisition unit to acquire a component image. When the type of electronic component targeted by the head unit for the component mounting operation is switched, multiple holding nozzles corresponding to that type of electronic component are attached to the head unit. Then, the imaging control unit repeats control of stopping the multiple holding nozzles at a predetermined reference position and rotating the polarizing filter at a specific rotation angle each time the type of electronic component is switched.

In the above component mounting machine, when the head unit equipped with multiple holding nozzles of different types performs the component mounting operation, the imaging control unit stops the polarizing filter at a predetermined reference position and rotates each of the multiple holding nozzles at the specific rotation angle corresponding to the type, and then causes the image acquisition unit to acquire the component image.

In this aspect, when a head unit equipped with multiple holding nozzles of different types performs a component mounting operation, the imaging control unit stops the polarizing filter at a predetermined reference position and rotates each of the multiple holding nozzles by a specific rotation angle according to their type before causing the image acquisition unit to acquire a component image.

In the above component mounting machine, when the head unit equipped with multiple holding nozzles of different types performs the component mounting operation, the imaging control unit stops the polarizing filter at a predetermined reference position before the electronic component is held on the holding surface, rotates each of the multiple holding nozzles by the specific rotation angle corresponding to the type, and then causes the image acquisition unit to acquire the component image while the electronic component is held on the holding surface.

In this aspect, when a head unit equipped with multiple holding nozzles of different types performs a component mounting operation, the imaging control unit stops the polarizing filter at a predetermined reference position before an electronic component is held on the holding surface, rotates each of the multiple holding nozzles by a specific rotation angle according to their type, and then causes the image acquisition unit to acquire a component image with the electronic component held on the holding surface. In this case, when the image acquisition unit acquires each component image corresponding to each of the multiple holding nozzles, each electronic component held by each holding nozzle will be oriented in the same direction relative to each holding surface as viewed from the image acquisition unit.

In the above-mentioned component mounter, the image acquisition unit is a polarization camera equipped with a polarizer stacked imaging element in which a polarizer constituting the polarization unit is stacked on each pixel of the imaging element constituting the imaging unit.

In this aspect, by configuring the image acquisition unit with a polarized camera, multiple polarized images with different polarization directions can be acquired with a single image capture of the electronic component held on the holding surface of the holding nozzle. The image acquisition unit can acquire, as a component image, an image from the multiple polarized images with a polarization direction corresponding to a polarizer that restricts the transmission of polarized light reflected by the holding surface and allows the transmission of unpolarized light reflected by the electronic component.

As described above, the present invention provides a component mounter that can accurately image-recognize an electronic component held on the holding surface of a holding nozzle.

1 is a block diagram of a component mounter according to an embodiment of the present invention. 2 is a plan view showing a configuration of a mounter body in the component mounter. FIG. 2 is a diagram illustrating a schematic diagram of a light irradiation unit and an image acquisition unit provided in the component mounter. FIG. 13 is a diagram for explaining the processing of the imaging control unit when a head unit to which a plurality of holding nozzles of the same type are attached performs a component mounting operation. FIG. 13 is a diagram for explaining the processing of the imaging control unit when a head unit to which a plurality of holding nozzles of different types is attached performs a component mounting operation. FIG. 13 is a diagram for explaining another example of the process of the imaging control unit when a head unit to which a plurality of holding nozzles of different types is attached performs a component mounting operation. FIG. FIG. 13 is a diagram showing a modified example of the image acquisition unit.

The following describes a component mounter according to an embodiment of the present invention with reference to the drawings. Note that directional relationships are described below using XY Cartesian coordinates that are mutually orthogonal on a horizontal plane.

The component mounter 1 shown in Figures 1 and 2 is a device that mounts (mounts) electronic components on a substrate PP to produce an electronic circuit board. There are multiple types of electronic components classified according to differences in shape, etc. Examples of electronic components include chip components with electrodes provided at one end and the other end of the component body, SOP (Small Outline Package), QFP (Quad Flat Package), PLCC (Plastic Leaded Chip Carrier), BGA (Ball Grid Array), and other multiple types of components. SOP is a component in which multiple electrodes are arranged at one end and the other end of the component body in the X-axis direction. QFP and PLCC are components in which multiple electrodes are arranged at one end and the other end of the component body in the X-axis direction and multiple electrodes are arranged at one end and the other end of the component body in the Y-axis direction. A BGA is a component that has multiple ball-shaped electrodes on the underside of the component body. However, there are also electronic components in which the electrodes are not exposed on the underside of the component body.

The component mounter 1 comprises a mounter main body 2, a control device 3, an image recognition device 4, and a storage device 5.

The mounting machine main body 2 constitutes a structural portion that performs operations such as component mounting, which mounts electronic components on the substrate PP during the production of electronic circuit boards. A solder paste pattern is printed on the substrate PP before the mounting machine main body 2 mounts the electronic components. In other words, the mounting machine main body 2 mounts electronic components on the substrate PP on which the solder paste pattern has been printed. The mounting machine main body 2 comprises a main body frame 21, a substrate transport section 22, a component supply device 23, a head unit 25, and a substrate support device 28.

The main body frame 21 is a structure in which each part constituting the mounting machine main body 2 is arranged, and is formed in a substantially rectangular shape in a plan view when viewed from a direction (vertical direction) perpendicular to both the X-axis direction and the Y-axis direction. The board transport section 22 is formed of a conveyor, and is arranged on the main body frame 21 so as to extend in the X-axis direction. The board transport section 22 transports the board PP in the X-axis direction. The board PP transported by the board transport section 22 is positioned by the board support device 28 at a predetermined work position (a component mounting position where components are mounted on the board PP). The board support device 28 positions the board PP at the component mounting position by supporting the board PP from below.

The component supply devices 23 are disposed in the respective regions at both ends of the main frame 21 in the Y-axis direction. The component supply device 23 is not particularly limited in the component supply method as long as it is configured to be able to supply electronic components. For example, the component supply device 23 may be a tape feeder that supplies electronic components using a tape as a carrier, a tray feeder that supplies electronic components by moving a pallet including a tray on which electronic components are placed, or a stick feeder that supplies electronic components stored in a cylindrical stick while pushing the electronic components out of the stick.

The head unit 25 is held by the moving frame 27. On the main frame 21, a fixed rail 261 extending in the Y-axis direction and a ball screw shaft 262 rotated by a Y-axis servo motor 263 are arranged. The moving frame 27 is arranged on the fixed rail 261, and a nut portion 271 provided on the moving frame 27 is screwed onto the ball screw shaft 262. In addition, a guide member 272 extending in the X-axis direction and a ball screw shaft 273 driven by an X-axis servo motor 274 are arranged on the moving frame 27. The head unit 25 is movably held by the guide member 272, and a nut portion provided on the head unit 25 is screwed onto the ball screw shaft 273. The moving frame 27 moves in the Y-axis direction by the operation of the Y-axis servo motor 263, and the head unit 25 moves in the X-axis direction relative to the moving frame 27 by the operation of the X-axis servo motor 274. That is, the head unit 25 can move in the Y-axis direction in conjunction with the movement of the moving frame 27, and can move in the X-axis direction along the moving frame 27. The head unit 25 can move between the component supply device 23 and the substrate PP supported by the substrate support device 28.

As shown in FIG. 3, the head unit 25 has a plurality of holding nozzles 251. Each holding nozzle 251 is, for example, a nozzle capable of suctioning and holding an electronic component P supplied by the component supply device 23. In this case, each holding nozzle 251 can be connected to either a negative pressure generating device, a positive pressure generating device, or the atmosphere via an electric switching valve. In other words, negative pressure is supplied to each holding nozzle 251, enabling the holding nozzle 251 to suction and hold the electronic component P, and then positive pressure is supplied to release the suction and holding of the electronic component P.

Each holding nozzle 251 can move up and down in the vertical direction (Z-axis direction) perpendicular to both the X-axis direction and the Y-axis direction relative to the frame of the head unit 25, and can rotate around a nozzle axis J1 extending in the Z-axis direction. Each holding nozzle 251 can move up and down along the Z-axis direction between a holding position where the electronic component P supplied by the component supply device 23 can be held and a retreat position above the holding position. In other words, when holding the electronic component P supplied by the component supply device 23, each holding nozzle 251 descends from the retreat position to the holding position and holds the electronic component P at the holding position. On the other hand, after holding the electronic component P, each holding nozzle 251 rises from the holding position to the retreat position. Furthermore, each holding nozzle 251 can move up and down along the Z-axis direction between a mounting position where the held electronic component P can be mounted at a predetermined target mounting position on the substrate PP and the retreat position.

Each holding nozzle 251 has a holding surface 2511 that holds an electronic component P, and is detachably attached to the head unit 25. The holding surface 2511 has a property of reflecting holding surface reflected polarized light L2, which is polarized in a specific direction, when unpolarized light L1 is incident on the holding surface 2511. The holding surface 2511 having such a property is made of, for example, carbon fiber reinforced plastic or carbon fiber reinforced carbon composite material made of carbon fiber. In this case, the polarization direction of the holding surface reflected polarized light L2 of the holding surface 2511 is determined by the direction in which the carbon fibers extend. The holding nozzle 251 has multiple types of nozzles that are classified according to the type of electronic component P and have different polarization directions of the holding surface reflected polarized light L2 on the holding surface 2511.

The head unit 25 performs a component mounting operation to mount the electronic components P held by each holding nozzle 251 onto the substrate PP at each of a number of target mounting positions set on the substrate PP.

As shown in FIG. 2, the head unit 25 is provided with a first imaging camera 252 and a second imaging camera 253. The first imaging camera 252 and the second imaging camera 253 are cameras equipped with imaging elements such as a complementary metal-oxide-semiconductor (CMOS) or a charged-coupled device (CCD).

The first imaging camera 252 captures an image of the mark M from above to recognize the mark M affixed to the top surface of the substrate PP transported to the component mounting position by the substrate transport section 22. By performing image recognition of the mark M on the substrate PP based on the image captured by the first imaging camera 252, the amount of positional deviation from the origin coordinates of the substrate PP is detected.

The second imaging camera 253 captures an image of the supply position of the electronic component P in the component supply device 23 from diagonally above. The image captured by the second imaging camera 253 is referenced when recognizing the posture of the electronic component P supplied to the component supply position by the component supply device 23.

The storage device 5 includes a management data storage unit 51 that stores management data D1 referenced by the control device 3, and an accumulation storage unit 52 that accumulates and stores part data D2 referenced by the image recognition device 4.

The management data D1 stored in the management data storage unit 51 is data composed of various information necessary for the control of component mounting processing, etc. by the control device 3. Examples of information constituting the management data D1 include component information, component supply information, nozzle information, head information, target holding position information, and target mounting position information. The component information is information for identifying the type of electronic component P. The component supply information is information for identifying the component supply device 23. The nozzle information is information for identifying the type of holding nozzle 251. The head information is information for identifying the head unit 25. The target holding position information is information indicating the target holding position when the holding nozzle 251 holds the electronic component P. The target mounting position information is information indicating the target mounting position of the electronic component P set on the board PP.

As shown in FIG. 1, the management data storage unit 51 stores the management data D1 in association with a specific rotation angle DS used by the imaging control unit 43 of the image recognition device 4 described below.

With reference to FIG. 1, the component data D2 stored in the accumulation memory unit 52 will be described. The component data D2 is composed of data related to the characteristics of the electronic component P. Examples of data related to the characteristics of the electronic component P include the external dimensions of the electronic component P, the size of the electrodes P2 (FIG. 3) in the electronic component P, the shape of the electrodes P2, and, in the case of an electronic component P in which multiple electrodes P2 are arranged in a predetermined arrangement direction relative to the component body P1 (FIG. 3), the pitch between the electrodes P2. The accumulation memory unit 52 accumulates and stores the component data D2 for each type of electronic component P. Note that the accumulation memory unit 52 is not limited to being included in the storage device 5 provided in the component mounter 1. For example, the accumulation memory unit 52 may be incorporated in a server device separate and independent of the component mounter 1.

The control device 3 is composed of a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores a control program, and a RAM (Random Access Memory) that is used as a working area for the CPU. The control device 3 controls the operation of each component of the mounting machine main body 2 by the CPU executing the control program stored in the ROM. The control device 3 controls the operation of each component according to the management data D1 stored in the management data storage unit 51. As shown in FIG. 1, the control device 3 includes, as its main functional components, a board transport control unit 31, a component supply control unit 32, and a head control unit 33.

The board transport control unit 31 controls the transport operation of the board PP by the board transport unit 22. The component supply control unit 32 controls the supply operation of the electronic components P by the component supply device 23 according to the component information and component supply information in the management data D1. The head control unit 33 controls the holding nozzle 251 by controlling the head unit 25 according to the component information, nozzle information, head information, target holding position information, and target mounting position information in the management data D1. As a result, the head control unit 33 causes the holding nozzle 251 to perform a holding operation to hold the electronic components P corresponding to each of the multiple target mounting positions set on the board PP, and also moves the head unit 25 to perform a component mounting operation.

The image recognition device 4 is a device for image-recognizing the electronic component P held by the holding surface 2511 of the holding nozzle 251. The image recognition device 4 will be described with reference to Figures 3 to 6 in addition to Figures 1 and 2.

The electronic component P that is the subject of image recognition by the image recognition device 4 has a component body P1 and an electrode P2. In the electronic component P, the electrode P2 made of metal has a reflection characteristic of specularly reflecting incident light, and the component body P1 made of a non-metal such as ceramics or resin has a reflection characteristic of diffusely reflecting incident light. Furthermore, an electronic component P in which the electrode P2 is not exposed on the underside of the component body P1 has a reflection characteristic of diffusely reflecting incident light. In the following, an electronic component P provided with an electrode P2 that has a reflection characteristic of specular reflection will be treated as a component that has a reflection characteristic of specular reflection, and an electronic component P in which the electrode P is not exposed will be treated as a component that has a reflection characteristic of diffuse reflection.

As described above, the holding surface 2511 of the holding nozzle 251 has the property of reflecting holding surface reflected polarized light L2, which is polarized in a specific direction, when unpolarized light L1 is incident on the holding surface 2511.

The image recognition device 4 performs image recognition of the electronic component P held on the holding surface 2511 of the holding nozzle 251 before the electronic component P held on the holding surface 2511 is mounted on the substrate PP. The image recognition device 4 includes a light irradiation unit 41, an image acquisition unit 42, an image capture control unit 43, and an image recognition unit 44. The light irradiation unit 41 and the image acquisition unit 42 are disposed on the main body frame 21 (see FIG. 2). Meanwhile, the image capture control unit 43 and the image recognition unit 44 may be configured by a microcomputer separate and independent from the control device 3 described above, or may be integrated into the control device 3.

As shown in FIG. 3, the light irradiation unit 41 irradiates the electronic component P held by the holding surface 2511 of the holding nozzle 251 with unpolarized light L1 from diagonally below. The light reflected by the holding surface 2511 in response to the incidence of the unpolarized light L1 irradiated from the light irradiation unit 41 becomes holding surface reflected polarized light L2, which is polarized in a specific direction. On the other hand, when the unpolarized light L1 irradiated from the light irradiation unit 41 is incident on the electronic component P, the reflected light from the electronic component P becomes unpolarized light L3, regardless of whether the electronic component P has the reflection characteristics of specular reflection or diffuse reflection.

The image acquisition unit 42 is positioned below the electronic component P held by the holding surface 2511 of the holding nozzle 251, and acquires a component image G1 based on unpolarized light L3 reflected by the electronic component P in response to the incidence of light L1 irradiated from the light irradiation unit 41. The component image G1 includes a component image area AR1 corresponding to the electronic component P and a holding surface image area AR2 that serves as the background and corresponds to the holding surface 2511. The component image area AR1 includes an electrode image area AR11 corresponding to the electrode P2 and a component body image area AR12 corresponding to the component body P1.

The image acquisition unit 42 includes a polarizing unit 422 and an imaging unit 421. The polarizing unit 422 restricts the transmission of the holding surface reflected polarized light L2 reflected by the holding surface 2511 in response to the incidence of unpolarized light L1. On the other hand, the reflected light from the electronic component P in response to the incidence of unpolarized light L1 is unpolarized light L3, so the reflected light from this electronic component P passes through the polarizing unit 422. The imaging unit 421 generates a component image G1 by receiving the light that has passed through the polarizing unit 422. The transmission of the holding surface reflected polarized light L2 reflected by the holding surface 2511 through the polarizing unit 422 is restricted, and the unpolarized light L3 reflected by the electronic component P passes through the polarizing unit 422, so that the component image G1 becomes an image in which the contrast between the component image area AR1 corresponding to the electronic component P and the holding surface image area AR2 corresponding to the holding surface 2511 is enhanced. Therefore, it is possible to accurately recognize the electronic component P held by the holding surface 2511 of the holding nozzle 251 based on the component image G1 acquired by the image acquisition unit 42.

In this embodiment, the image acquisition unit 42 is a camera in which an image sensor constituting the image capture unit 421 and a polarizing filter constituting the polarizing unit 422 are arranged side by side on the optical axis J2. The polarizing filter constituting the polarizing unit 422 is rotatable around the optical axis J2. As described above, the holding nozzle 251 is rotatable around the nozzle axis J1. When the image acquisition unit 42 acquires the component image G1, the head unit 25 moves so that the nozzle axis J1 is positioned coaxially with the optical axis J2.

With the nozzle axis J1 and the optical axis J2 arranged coaxially, the imaging control unit 43 adjusts the rotation angle of at least one of the polarizing filter and the holding nozzle 251 that constitute the polarizing unit 422, thereby adjusting the degree to which the holding surface reflected polarized light L2 reflected by the holding surface 2511 of the holding nozzle 251 is restricted from passing through the polarizing filter. After this adjustment, the imaging control unit 43 causes the image acquisition unit 42 to acquire the component image G1.

The imaging control unit 43 performs a test image acquisition process and a setting process before causing the image acquisition unit 42 to acquire the component image G1. In the test image acquisition process, the imaging control unit 43 rotates at least one of the polarizing filter and the holding nozzle 251 that constitute the polarizing unit 422 by a predetermined rotation angle, and causes the image acquisition unit 42 to acquire multiple test images for each rotation angle. In the setting process, the imaging control unit 43 identifies a test image with the highest contrast value from among the multiple test images, and can set the rotation angle corresponding to the identified test image as the specific rotation angle DS (FIG. 1) when causing the image acquisition unit 42 to acquire the component image G1. The specific rotation angle DS set by the imaging control unit 43 is associated with the management data D1 and stored in the management data storage unit 51.

The imaging control unit 43 rotates at least one of the polarizing filter and the holding nozzle 251 at a specific rotation angle DS from a predetermined reference position so that the polarizing filter constituting the polarizing unit 422 can restrict the transmission of the holding surface reflected polarized light L2, and then causes the image acquisition unit 42 to acquire a component image G1. This makes it possible to more reliably restrict the holding surface reflected polarized light L2 reflected by the holding surface 2511 of the holding nozzle 251 from passing through the polarizing filter constituting the polarizing unit 422. Therefore, the component image G1 acquired by the image acquisition unit 42 is an image in which the contrast between the component image area AR1 and the holding surface image area AR2 is more reliably enhanced. Therefore, it becomes possible to more accurately recognize the image of the electronic component P held by the holding surface 2511 of the holding nozzle 251 based on the component image G1 acquired by the image acquisition unit 42.

When rotating at least one of the polarizing filter and the holding nozzle 251, the imaging control unit 43 can refer to the specific rotation angle DS for each type of holding nozzle 251 associated with the management data D1 stored in the management data storage unit 51. In this case, the imaging control unit 43 rotates at least one of the polarizing filter and the holding nozzle 251 based on the specific rotation angle DS associated with the management data D1, and then causes the image acquisition unit 42 to acquire the component image G1.

As described above, the holding nozzle 251 has multiple types of nozzles with different polarization directions of the holding surface reflected polarized light L2 on the holding surface 2511. In this case, the specific rotation angle DS when the imaging control unit 43 causes the image acquisition unit 42 to acquire the component image G1 is set for each type of holding nozzle 251. The imaging control unit 43 rotates at least one of the polarizing filter constituting the polarizing unit 422 and the holding nozzle 251 at the specific rotation angle DS for each type of holding nozzle 251. This makes it possible to restrict the holding surface reflected polarized light L2 reflected by the holding surface 2511 of the holding nozzle 251 from passing through the polarizing filter in the multiple types of holding nozzles 251. As a result, the component image G1 acquired by the image acquisition unit 42 corresponding to each of the multiple types of holding nozzles 251 becomes an image with enhanced contrast between the component image area AR1 and the holding surface image area AR2.

As shown in FIG. 4, when the head unit 25 equipped with multiple holding nozzles 251 of the same type performs a component mounting operation, the imaging control unit 43 stops the multiple holding nozzles 251 at a predetermined reference position and rotates the polarizing filter constituting the polarizing unit 422 at a specific rotation angle DS that can regulate the transmission of the holding surface reflected polarized light L2 before causing the image acquisition unit 42 to acquire the component image G1. When the type of electronic component P targeted by the head unit 25 for the component mounting operation is changed, multiple holding nozzles 251 corresponding to the type of electronic component P are attached to the head unit 25. Then, the imaging control unit 43 repeats the control of stopping the multiple holding nozzles 251 at a predetermined reference position and rotating the polarizing filter at the specific rotation angle DS every time the type of electronic component P is changed.

As shown in FIG. 5, a case is assumed in which the head unit 25 equipped with multiple holding nozzles 251 of different types performs a component mounting operation. The holding surface 251 of each holding nozzle 251 has, for example, a rectangular shape. With an electronic component P held on the holding surface 2511 of each holding nozzle 251, the imaging control unit 43 stops the polarizing filter constituting the polarizing unit 422 at a predetermined reference position and rotates each of the multiple holding nozzles 251 at a specific rotation angle DS according to the type before causing the image acquisition unit 42 to acquire a component image G1. In this case, when the image acquisition unit 42 acquires each component image G1 corresponding to each of the multiple holding nozzles 251, the electronic component P held by each holding nozzle 251 as viewed from the image acquisition unit 42 side takes a posture facing a different direction for each type of holding nozzle 251 with respect to each holding surface 2511.

6, when the head unit 25 equipped with a plurality of different types of holding nozzles 251 performs a component mounting operation, the imaging control unit 43 may be configured to perform the following processing. In the example shown in FIG. 6, the holding surface 251 of each holding nozzle 251 has, for example, a circular shape. Before the electronic component P is held on the holding surface 2511 of each holding nozzle 251, the imaging control unit 43 stops the polarizing filter constituting the polarizing unit 422 at a predetermined reference position, rotates each of the plurality of holding nozzles 251 at a specific rotation angle DS according to the type, and then causes the image acquisition unit 42 to acquire each component image G1 in a state in which the electronic component P is held on each holding surface 2511. In this case, when the image acquisition unit 42 acquires each component image G1 corresponding to each of the plurality of holding nozzles 251, the electronic components P held by each holding nozzle 251 will take a posture facing the same direction with respect to each holding surface 2511 as viewed from the image acquisition unit 42 side. In this case, when the head control unit 33 described below controls the component mounting operation of the head unit 25 based on the recognition result using the component image G1 by the image recognition unit 44, the amount of rotation of the holding nozzle 251 when rotating to adjust the attitude of the electronic component P when mounted on the substrate PP can be reduced. This makes it possible to prevent the time for the component mounting operation by the head unit 25 from becoming longer in accordance with the rotation of the holding nozzle 251, and also to prevent the positional deviation of the electronic component P relative to the holding surface 2511 caused by the rotation of the holding nozzle 251.

The image recognition unit 44 performs image recognition of the electronic component P held by the holding nozzle 251 based on the component image G1 acquired by the image acquisition unit 42 and the component data D2 stored in the accumulation memory unit 52. Specifically, the image recognition unit 44 recognizes the position of the electronic component P relative to the holding nozzle 251 as the holding state of the electronic component P relative to the holding nozzle 251, and recognizes the posture of the electronic component P held by the holding nozzle 251, based on the component image G1 while referring to the component data D2.

The recognition results by the image recognition unit 44 are input to the head control unit 33. The head control unit 33 controls the component mounting operation by the head unit 25 based on the recognition results by the image recognition unit 44. The component mounting operation of the head unit 25, which is controlled based on the recognition results by the image recognition unit 44, improves the mounting accuracy of the electronic components P on the substrate PP.

The above describes the component mounter 1 to which the image recognition device 4 according to an embodiment of the present invention is applied, but the present invention is not limited to this, and for example, the following modified embodiments can be adopted.

In the above embodiment, the image acquisition unit 42 of the image recognition device 4 is described as being configured by a camera in which the image sensor constituting the image capture unit 421 and the polarizing filter constituting the polarizing unit 422 are arranged side by side on the optical axis J2 at a predetermined distance, but is not limited to such a configuration.

In a modified embodiment, the image acquisition unit 42 may be a camera having the structure shown in FIG. 7. In the example shown in FIG. 7, the image acquisition unit 42 is configured by a polarized camera equipped with a polarizer stacked imaging element 42A in which polarizers with different polarization directions that constitute the polarizing unit 422 are stacked on each pixel of an imaging element such as a CMOS or CCD that constitutes the imaging unit 421. Each pixel that constitutes the polarizer stacked imaging element 42A is provided with a polarizer that functions as the polarizing unit 422 that transmits only light polarized in a specific direction. An imaging element that constitutes the imaging unit 421 that receives light that has passed through the polarizer is provided below the polarizer that constitutes the polarizing unit 422.

The polarizers set in each pixel constituting the polarizer stack imaging element 42A are configured so that a plurality of pixels (for example, four pixels) are treated as one unit and each of these plurality of pixels (four pixels) transmits only light of a different polarization direction. In the case of the polarizer stack imaging element 42A in which polarizers each consisting of four pixels are stacked, the polarization directions of the four pixels a, b, c, and d of the polarizer stack imaging element 42A are set, for example, as follows. That is, the polarization direction of pixel a is the horizontal direction of 0 degrees, and in this case, pixel a receives only light polarized in the 0 degree direction. The polarization direction of pixel b is the upper right diagonal direction of 45 degrees, and in this case, pixel b receives only light polarized in the 45 degree direction. The polarization direction of pixel c is the vertical direction of 90 degrees, and in this case, pixel c receives only light polarized in the 90 degree direction. The polarization direction of pixel d is the lower right diagonal direction of 135 degrees, and in this case, pixel d receives only light polarized in the 135 degree direction.

In the above explanation, the horizontal direction, upper right diagonal direction, lower right diagonal direction, and vertical direction are directions relative to the polarization camera that constitutes the image acquisition unit 42, and the direction perpendicular to the optical axis of the polarization camera is the horizontal direction, and the direction parallel to the optical axis of the polarization camera is the vertical direction. Therefore, the polarization direction of each pixel changes depending on the tilt of the polarization camera.

The image acquisition unit 42, which is configured with a polarized camera equipped with a polarizer stacked imaging element 42A in which polarizers with four pixels as one unit are stacked, acquires polarized images with polarization directions of 0 degrees, 45 degrees, 90 degrees, and 135 degrees based on the light L3 reflected by the electronic component P in response to the incidence of the unpolarized light L1 irradiated from the light irradiation unit 41. By configuring the image acquisition unit 42 with a polarized camera, four polarized images with different polarization directions can be acquired in one image acquisition from below the electronic component P held by the holding surface 2511 of the holding nozzle 251. The image acquisition unit 42 acquires, as the component image G1, an image of the polarization direction corresponding to the polarizer that restricts the transmission of the holding surface reflected polarized light L2 reflected by the holding surface 2511 and allows the transmission of the light L3 reflected by the electronic component P, among the four polarized images.

REFERENCE SIGNS LIST 1 Component mounter 2 Mounter body 25 Head unit 3 Control device 33 Head control section 4 Image recognition device 41 Light irradiation section 42 Image acquisition section 43 Imaging control section 44 Image recognition section 5 Storage device 51 Management data storage section

Claims (11)

a head unit to which a holding nozzle having a holding surface for holding an electronic component is attached, the head unit performing a component mounting operation for mounting the electronic component held on the holding surface onto a substrate;
a light irradiation unit that irradiates the electronic component held by the holding surface with unpolarized light;
an image acquisition unit that acquires a component image based on light reflected by the electronic component in response to the incidence of the unpolarized light,
the holding surface has a property of reflecting polarized light in a specific direction when the unpolarized light is incident thereon,
The image acquisition unit of this component mounter includes a polarizing unit that regulates the transmission of holding surface reflected polarized light, which is polarized light reflected by the holding surface, and an imaging unit that generates the component image by receiving light that has passed through the polarizing unit. an image recognition unit that performs image recognition of the electronic component held on the holding surface based on the component image acquired by the image acquisition unit;
The component mounter according to claim 1 , further comprising: a head control unit that controls the component mounting operation of the head unit based on a recognition result by the image recognition unit. the image acquisition unit is a camera in which an image sensor constituting the image capturing unit and a polarizing filter constituting the polarizing unit are arranged side by side on an optical axis,
the polarizing filter is rotatable about the optical axis;
The component mounter according to claim 2 , wherein the holding nozzle is rotatable about an axis. The component mounter according to claim 3 further comprises an imaging control unit that rotates at least one of the polarizing filter and the holding nozzle at a specific rotation angle from a predetermined reference position so that the polarizing filter can regulate the transmission of the polarized light reflected by the holding surface, and then causes the image acquisition unit to acquire the component image. The imaging control unit, before causing the image acquisition unit to acquire the component image,
a test image acquisition process in which at least one of the polarizing filter and the holding nozzle is rotated by a predetermined rotation angle and a plurality of test images for each of the rotation angles is acquired by the image acquisition unit;
5. The component mounter according to claim 4, further comprising a setting process for identifying a test image having a highest contrast value from among the plurality of test images, and setting a rotation angle corresponding to the identified test image as the specific rotation angle. the electronic components include a plurality of types of components classified according to differences in shape;
the holding nozzle includes a plurality of types of nozzles classified according to the type of the electronic component, the nozzles having different polarization directions of the holding surface reflected polarized light on the holding surface,
The component mounter according to claim 4 , wherein the specific rotation angle is set for each type of the holding nozzle. a management data storage unit configured to store management data including component information for identifying a type of the electronic component and nozzle information for identifying a type of the holding nozzle,
the management data storage unit stores the specific rotation angle for each type of the holding nozzle in association with the management data;
the imaging control unit rotates at least one of the polarizing filter and the holding nozzle based on the specific rotation angle associated with the management data, and then causes the image acquisition unit to acquire the component image;
The component mounter according to claim 6 , wherein the head control unit controls the component mounting operation of the head unit based on the management data. The component mounter according to claim 6 or 7, wherein, when the head unit to which the same type of holding nozzles are attached performs the component mounting operation, the imaging control unit stops the holding nozzles at a predetermined reference position and rotates the polarizing filter at the specific rotation angle, and then causes the image acquisition unit to acquire the component image. The component mounter according to any one of claims 6 to 8, wherein the imaging control unit stops the polarizing filter at a predetermined reference position and rotates each of the multiple holding nozzles at the specific rotation angle corresponding to the type when the head unit equipped with multiple holding nozzles of different types performs the component mounting operation, and then causes the image acquisition unit to acquire the component image. The component mounter according to any one of claims 6 to 8, wherein when the head unit equipped with multiple holding nozzles of different types performs the component mounting operation, the imaging control unit stops the polarizing filter at a predetermined reference position before the electronic component is held on the holding surface, rotates each of the multiple holding nozzles by the specific rotation angle according to the type, and then causes the image acquisition unit to acquire the component image while the electronic component is held on the holding surface. The component mounter according to claim 1 or 2, wherein the image acquisition unit is a polarization camera equipped with a polarizer stacked imaging element in which a polarizer constituting the polarization unit is stacked on each pixel of an imaging element constituting the imaging unit.

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