JP7680342B2 - 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 on a board, a light irradiation unit that irradiates light onto the electronic component held on the holding surface, and an image acquisition unit that acquires a component image based on light reflected by the electronic component in response to the incidence of light irradiated by the light irradiation unit. The light irradiation unit includes a light emission unit that emits unpolarized light, and an irradiation polarization unit that is detachably arranged at a position on the side from which the light of the light emission unit is emitted based on whether the holding surface has a characteristic of reflecting holding surface reflected polarized light, which is polarized in a specific direction in response to the incidence of light, and that allows the transmission of a specific irradiation polarized light, which is polarized in a specific direction, for the light emitted from the light emission unit. When the illumination polarizing unit is omitted due to the holding surface having a characteristic of reflecting the holding surface reflected polarized light, the light illumination unit illuminates the electronic component with unpolarized light emitted from the light emission unit, while when the illumination polarizing unit is arranged, the light illumination unit illuminates the electronic component with the specific illumination polarized light. The image acquisition unit includes an imaging polarization unit that restricts or allows the transmission of polarized light in a specific direction, and an imaging unit that generates the component image by receiving light that has passed through the imaging polarization unit. The imaging polarization unit switches the polarization direction of the polarized light that restricts or allows the transmission depending on whether the illumination polarizing unit is arranged.

According to this component mounter, the light irradiation unit irradiates light onto the electronic component held on the holding surface of the holding nozzle, and the image acquisition unit acquires a component image based on the light reflected by the electronic component. The light irradiation unit includes a light emission unit that emits unpolarized light, and an irradiation polarization unit that is detachably positioned at a position on the side from which the light from the light emission unit is emitted based on whether or not the holding surface has the property of reflecting holding surface reflected polarized light, which is polarized in a specific direction. The image acquisition unit includes an imaging polarization unit, and an imaging unit that generates a component image by receiving light that has passed through the imaging polarization unit.

In the light irradiation unit, if the holding surface has the property of reflecting the polarized light reflected by the holding surface, the arrangement of the irradiation polarization unit is omitted. In this case, the light irradiation unit irradiates the unpolarized light emitted from the light emission unit toward the electronic component held by the holding surface of the holding nozzle. On the other hand, when the irradiation polarization unit is arranged, the light irradiation unit irradiates the electronic component with specific irradiation polarized light, which is polarized in a specific direction that has passed through the irradiation polarization unit. In this way, whether or not the irradiation polarization unit is arranged is determined depending on whether or not the holding surface of the holding nozzle has the property of reflecting the polarized light reflected by the holding surface, and accordingly, the light irradiated to the electronic component switches between unpolarized light and specific irradiation polarized light.

There are electronic components that have the reflection characteristics of specular reflection and those that have the reflection characteristics of diffuse reflection. For example, an electronic component in which a metal electrode is exposed on the underside opposite to the side that abuts on the holding surface has the reflection characteristics of specular reflection, and an electronic component in which the electrode is not exposed has the reflection characteristics of diffuse reflection. When non-polarized light irradiated from a light irradiation unit in which the irradiation polarizing unit is omitted 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 characteristics of specular reflection or diffuse reflection. On the other hand, when a specific irradiation polarized light irradiated from a light irradiation unit in which an irradiation polarizing unit is arranged is incident on an electronic component, the reflected light in the case of a component having the reflection characteristics of specular reflection becomes polarized in the same polarization direction as the specific irradiation polarized light, and the reflected light in the case of a component having the reflection characteristics of diffuse reflection becomes non-polarized light. In this way, the polarization characteristics of the reflected light from the electronic component change as the polarization characteristics of the light irradiated from the light irradiation unit change depending on whether the irradiation polarizing unit is arranged or not.

In the image acquisition section that acquires a component image based on light reflected by an electronic component, the imaging polarization section switches the polarization direction of the polarized light that restricts or allows transmission depending on whether an irradiation polarization section is arranged. The imaging section then generates a component image by receiving the light that has passed through the imaging polarization section. As a result, 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 section.

In the above-mentioned component mounter, when the illumination polarization unit is omitted, the imaging polarization unit restricts the transmission of polarized light having the same polarization direction as the holding surface reflected polarized light reflected by the holding surface in response to illumination of unpolarized light by the light illumination unit, and allows the transmission of unpolarized light reflected by the electronic component.

In this embodiment, when the irradiation polarization unit is omitted, the imaging polarization unit restricts the transmission of polarized light having the same polarization direction as the holding surface reflected polarized light reflected by the holding surface in response to the irradiation of unpolarized light by the light irradiation unit, and allows the transmission of unpolarized light reflected by the electronic component. In this case, the imaging unit generates a component image by receiving unpolarized light that has been transmitted through the imaging polarization unit and has been reflected by the electronic component. Since the transmission of the holding surface reflected polarized light reflected by the holding surface is restricted through the imaging polarization unit, and the unpolarized light reflected by the electronic component is transmitted through the imaging polarization unit, the component image has a bright component image area and a dark holding surface image area, resulting in an image with enhanced contrast between the respective areas. 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.

In the above-mentioned component mounting machine, when the irradiation polarization unit is disposed, the holding surface has a reflective property of diffuse reflection, and the electronic component has a reflective property of specular reflection, the imaging polarization unit restricts the transmission of non-polarized light diffusely reflected by the holding surface in response to the irradiation of the specific irradiation polarized light by the light irradiation unit, and allows the transmission of polarized light having the same polarization direction as the specific irradiation polarized light specularly reflected by the electronic component.

In this embodiment, when the irradiation polarizing unit is disposed, the holding surface has a reflective characteristic of diffuse reflection, and the electronic component has a reflective characteristic of specular reflection, the imaging polarizing unit restricts the transmission of non-polarized light diffusely reflected by the holding surface in response to the irradiation of the specific irradiation polarized light by the light irradiation unit, and allows the transmission of polarized light having the same polarization direction as the specific irradiation polarized light specularly reflected by the electronic component. In this case, the imaging unit generates a component image by receiving the polarized light that is transmitted through the imaging polarizing unit and specularly reflected by the electronic component. Since the transmission of the non-polarized light diffusely reflected by the holding surface is restricted through the imaging polarizing unit, and the polarized light specularly reflected by the electronic component is transmitted through the imaging polarizing unit, the component image region becomes a bright region and the holding surface image region becomes a dark region, resulting in an image with enhanced contrast between the respective regions. 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.

In the above-mentioned component mounting machine, when the irradiation polarization unit is disposed, the holding surface has a specular reflection characteristic, and the electronic component has a diffuse reflection characteristic, the imaging polarization unit allows the transmission of polarized light having the same polarization direction as the specific irradiation polarized light that is specularly reflected by the holding surface in response to the irradiation of the specific irradiation polarized light by the light irradiation unit, and restricts the transmission of unpolarized light that is diffusely reflected by the electronic component.

In this embodiment, when the irradiation polarizing unit is disposed, the holding surface has a specular reflection characteristic, and the electronic component has a diffuse reflection characteristic, the imaging polarizing unit allows the transmission of polarized light having the same polarization direction as the specific irradiation polarized light specularly reflected by the holding surface in response to the irradiation of the specific irradiation polarized light by the light irradiation unit, and restricts the transmission of non-polarized light diffusely reflected by the electronic component. In this case, the imaging unit generates a component image by receiving the polarized light that is transmitted through the imaging polarizing unit and specularly reflected by the holding surface. Since the polarized light specularly reflected by the holding surface is transmitted through the imaging polarizing unit, and the transmission of the non-polarized light diffusely reflected by the electronic component is restricted through the imaging polarizing unit, the component image region becomes a dark region and the holding surface image region becomes a light region, resulting in an image with enhanced contrast between the respective regions. 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.

In the above-mentioned component mounter, the image acquisition unit is a camera in which the imaging element constituting the imaging unit and the polarizing filter constituting the imaging polarization unit are arranged side by side on the optical axis.

In this embodiment, the image acquisition unit can be realized by a camera in which an image sensor constituting the imaging unit and a polarizing filter constituting the imaging polarization unit are arranged side by side on the optical axis.

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 imaging 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 polarization camera, multiple polarized images with different polarization directions can be acquired in a single image capture of the electronic component held on the holding surface of the holding nozzle. The image acquisition unit can acquire, from among the multiple polarized images, the image with the highest contrast between the component image area and the holding surface image area as the component image.

The component mounter further includes 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.

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. 13 is a diagram illustrating a schematic diagram of a light irradiation unit and an image acquisition unit in a case where a holding surface of a holding nozzle provided in a component mounter has a characteristic of reflecting polarized light in a specific direction. FIG. 13 is a diagram illustrating a schematic view of a light irradiation unit and an image acquisition unit in a case where the holding surface of the holding nozzle has a reflective property of diffuse reflection and the electronic component has a reflective property of specular reflection. FIG. 13 is a diagram illustrating a schematic view of a light irradiation unit and an image acquisition unit in a case where the holding surface of the holding nozzle has a specular reflection characteristic and the electronic component has a diffuse reflection characteristic. 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 Figures 3 to 6, 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, supplying negative pressure to each holding nozzle 251 enables the holding nozzle 251 to suction and hold the electronic component P, and then supplying positive pressure releases the suction and holding of the electronic component P.

Each holding nozzle 251 can be raised and lowered in a 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 extending in the Z-axis direction. Each holding nozzle 251 can be raised and lowered 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 be raised and lowered 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 the electronic component P, and is detachably attached to the head unit 25. The holding nozzle 251 has multiple types of nozzles according to the reflection characteristics of the holding surface 2511. The first type of holding nozzle 251 has a characteristic that the holding surface 2511 reflects holding surface reflected polarized light L2 (FIG. 3), which is polarized in a specific direction in response to the incidence of unpolarized light L1. The holding surface 2511 having such characteristics 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 fiber extends. The second type of holding nozzle 251 does not have the characteristic that the holding surface 2511 reflects the holding surface reflected polarized light L2, and has a reflection characteristic that the holding surface 2511 diffusely reflects the incident light. The holding surface 2511 having such a reflecting characteristic of diffuse reflection is made of a non-metal such as ceramics or polycrystalline sintered diamond (PCD). The third type of holding nozzle 251 has a holding surface 2511 that does not have the characteristic of reflecting the holding surface reflected polarized light L2, and has the reflecting characteristic of specularly reflecting the incident light. The holding surface 2511 having such a reflecting characteristic of specular reflection is made of, for example, a metal.

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.

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 nozzle 251 has multiple types of nozzles depending on the reflection characteristics of the holding surface 2511. In the first type of holding nozzle 251, the holding surface 2511 has the characteristic of reflecting holding surface reflected polarized light L2, which is polarized in a specific direction, in response to the incidence of unpolarized light L1. In the second type of holding nozzle 251, the holding surface 2511 has the reflection characteristic of diffusively reflecting the incident light. In the third type of holding nozzle 251, the holding surface 2511 has the reflection characteristic of specularly reflecting the incident light.

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, and an image recognition unit 43. The light irradiation unit 41 and the image acquisition unit 42 are arranged on the main body frame 21 (see FIG. 2). On the other hand, the image recognition unit 43 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.

The light irradiation unit 41 irradiates light from below at an angle onto the electronic component P held by the holding surface 2511 of the holding nozzle 251. The image acquisition unit 42, positioned below the electronic component P held by the holding surface 2511 of the holding nozzle 251, acquires a component image G1 based on light reflected by the electronic component P in response to the incidence of light 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 light irradiation unit 41 includes a light emission unit 411 that emits non-polarized light L1, and an irradiation polarization unit 412 that is detachably arranged at a position on the side from which the light of the light emission unit 411 is emitted based on whether the holding surface 2511 has the property of reflecting holding surface reflected polarized light L2, which is polarized in a specific direction. The image acquisition unit 42 includes an imaging polarization unit 422 that restricts or allows the transmission of polarized light in a specific direction, and an imaging unit 421 that generates a component image G1 by receiving light that has passed through the imaging polarization unit 422. In this embodiment, the image acquisition unit 42 is a camera in which an imaging element constituting the imaging unit 421 and a polarizing filter constituting the polarization unit 422 are arranged side by side on the optical axis.

In the light irradiation unit 41, when the holding surface 2511 has the property of reflecting the holding surface reflected polarized light L2, the arrangement of the irradiation polarization unit 412 is omitted. In this case, the light irradiation unit 41 irradiates the non-polarized light L1 emitted from the light emission unit 411 toward the electronic component P held by the holding surface 2511 of the holding nozzle 251. On the other hand, when the irradiation polarization unit 412 is arranged, the light irradiation unit 41 irradiates the electronic component P with the specific irradiation polarized light L11, which is polarized in a specific direction that has passed through the irradiation polarization unit 412. In this way, whether or not the irradiation polarization unit 412 is arranged is determined depending on whether or not the holding surface 2511 of the holding nozzle 251 has the property of reflecting the holding surface reflected polarized light L2, and accordingly, the light irradiated to the electronic component P is switched between the non-polarized light L1 and the specific irradiation polarized light L11.

As electronic components P, there are components having specular reflection characteristics and components having diffuse reflection characteristics. When the unpolarized light L1 irradiated from the light irradiation unit 41 in which the irradiation polarization unit 412 is omitted 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 specular reflection or diffuse reflection characteristics. On the other hand, when the specific irradiation polarized light L11 irradiated from the light irradiation unit 41 in which the irradiation polarization unit 412 is arranged is incident on the electronic component P, the reflected light in the case of a component having specular reflection characteristics becomes polarized light L31 with the same polarization direction as the specific irradiation polarized light, and the reflected light in the case of a component having diffuse reflection characteristics becomes unpolarized light L32. In this way, the polarization characteristics of the reflected light from the electronic component P change as the polarization characteristics of the light irradiated from the light irradiation unit 41 change depending on whether the irradiation polarization unit 412 is arranged or not.

In the image acquisition unit 42 that acquires a component image G1 based on light reflected by the electronic component P, the imaging polarization unit 422 switches the polarization direction of the polarized light that restricts or allows transmission depending on whether the irradiation polarization unit 412 is arranged. Then, the imaging unit 421 generates the component image G1 by receiving the light that has transmitted through the imaging polarization unit 422. As a result, 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 becomes 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.

The image recognition unit 43 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 43 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 43 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 43. The component mounting operation of the head unit 25, which is controlled based on the recognition results by the image recognition unit 43, improves the mounting accuracy of the electronic components P on the substrate PP.

3, when the arrangement of the irradiation polarization unit 412 is omitted in the light irradiation unit 41 due to the holding surface 2511 having the property of reflecting the holding surface reflected polarized light L2, the imaging polarization unit 422 restricts the transmission of polarized light having the same polarization direction as the holding surface reflected polarized light L2 reflected by the holding surface 2511 in response to the irradiation of unpolarized light L1 by the light irradiation unit 41, and allows the transmission of unpolarized light L3 reflected by the electronic component P. In this case, the imaging unit 421 generates a component image G1 by receiving the unpolarized light L3 reflected by the electronic component P, which is light L4 transmitted through the imaging polarization unit 422. The holding surface reflected polarized light L2 reflected by the holding surface 2511 is restricted from passing through the imaging polarization unit 422, and the non-polarized light L3 reflected by the electronic component P passes through the imaging polarization unit 422, so that the component image G1 has a bright component image area AR1 and a dark holding surface image area AR2, resulting in an image with enhanced contrast between the respective areas. Therefore, based on the component image G1 acquired by the image acquisition unit 42, it is possible to accurately recognize the image of the electronic component P held by the holding surface 2511 of the holding nozzle 251.

4, when the irradiation polarization unit 412 is disposed in the light irradiation unit 41, the holding surface 2511 has a reflective characteristic of diffuse reflection, and the electronic component P has a reflective characteristic of specular reflection, the imaging polarization unit 422 restricts the transmission of unpolarized light L21 diffusely reflected by the holding surface 2511 in response to the irradiation of specific irradiation polarized light L11 by the light irradiation unit 41, and allows the transmission of polarized light L31 having the same polarization direction as the specific irradiation polarized light L11 specularly reflected by the electronic component P. In this case, the imaging unit 421 generates a component image G1 by receiving polarized light L31 that is specularly reflected by the electronic component P and is light L4 that has passed through the imaging polarization unit 422. The non-polarized light L21 diffusely reflected by the holding surface 2511 is restricted from passing through the imaging polarization unit 422, and the polarized light L31 specularly reflected by the electronic component P passes through the imaging polarization unit 422, so that the component image G1 has a bright component image area AR1 and a dark holding surface image area AR2, resulting in an image with enhanced contrast between the respective areas. 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.

5, when the irradiation polarization unit 412 is disposed in the light irradiation unit 41, the holding surface 2511 has a specular reflection characteristic, and the electronic component P has a diffuse reflection characteristic, the imaging polarization unit 422 allows the transmission of polarized light L22 having the same polarization direction as the specific irradiation polarized light L11 specularly reflected by the holding surface 2511 in response to the irradiation of the specific irradiation polarized light L11 by the light irradiation unit 41, and restricts the transmission of unpolarized light L32 diffusely reflected by the electronic component P. In this case, the imaging unit 421 generates a component image G1 by receiving polarized light L22 specularly reflected by the holding surface 2511, which is light L5 transmitted through the imaging polarization unit 422. Polarized light L22 specularly reflected by the holding surface 2511 passes through the imaging polarization unit 422, while non-polarized light L32 diffusely reflected by the electronic component P is restricted from passing through the imaging polarization unit 422, so that in the component image G1, the component image area AR1 becomes a dark area and the holding surface image area AR2 becomes a light area, resulting in an image with enhanced contrast between the areas. Therefore, based on the component image G1 acquired by the image acquisition unit 42, it becomes possible to accurately recognize the image of the electronic component P held by the holding surface 2511 of the holding nozzle 251.

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 imaging unit 421 and the polarizing filter constituting the imaging polarization unit 422 are arranged side by side on the optical axis 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. 6. In the example shown in FIG. 6, the image acquisition unit 42 is configured by a polarized camera in which a polarizer stacked imaging element 42A is mounted on each pixel of an imaging element such as a CMOS or CCD that constitutes the imaging unit 421, and polarizers with different polarization directions that constitute the imaging polarization unit 422 are stacked. Each pixel that constitutes the polarizer stacked imaging element 42A is provided with a polarizer that functions as the imaging polarization 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 imaging polarization 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 light L3 reflected by the electronic component P in response to the incidence of 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 capture from below the electronic component P held by the holding surface 2511 of the holding nozzle 251. The image acquisition unit 42 can acquire, from among the four polarized images, the image with the highest contrast between the component image area AR1 and the holding surface image area AR2 as the component image G1.

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

Claims (7)

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 light onto the electronic component held by the holding surface;
an image acquisition unit that acquires a component image based on light reflected by the electronic component in response to the incidence of light irradiated by the light irradiation unit,
The light irradiation unit includes:
a light output section that outputs unpolarized light;
an illumination polarization unit that is detachably disposed at a position on the light output side of the light output unit based on whether the holding surface has a characteristic of reflecting holding surface reflected polarized light, which is polarized in a specific direction in response to the incidence of light, and that allows transmission of a specific illumination polarized light, which is polarized in a specific direction, for the light output from the light output unit;
When the arrangement of the irradiation polarization unit is omitted due to the holding surface having a characteristic of reflecting the holding surface reflected polarized light, the non-polarized light emitted from the light output unit is irradiated toward the electronic component, while when the irradiation polarization unit is arranged, the specific irradiation polarized light is irradiated toward the electronic component;
The image acquisition unit includes:
an imaging polarization unit that restricts or allows transmission of polarized light in a specific direction;
an imaging unit that generates the component image by receiving light that has passed through the imaging polarization unit,
The imaging polarization unit is capable of switching a polarization direction of polarized light that restricts or allows transmission depending on whether the illumination polarization unit is arranged. The component mounter according to claim 1, wherein, when the illumination polarization unit is omitted, the imaging polarization unit restricts transmission of polarized light having the same polarization direction as the holding surface reflected polarized light reflected by the holding surface in response to illumination of unpolarized light by the light illumination unit, and allows transmission of unpolarized light reflected by the electronic component. The component mounter according to claim 1 or 2, wherein, when the illumination polarization unit is disposed, the holding surface has a reflective characteristic of diffuse reflection, and the electronic component has a reflective characteristic of specular reflection, the imaging polarization unit restricts the transmission of non-polarized light diffusely reflected by the holding surface in response to the illumination of the specific illumination polarized light by the light illumination unit, and allows the transmission of polarized light having the same polarization direction as the specific illumination polarized light specularly reflected by the electronic component. The component mounter according to any one of claims 1 to 3, wherein when the illumination polarization unit is disposed, the holding surface has a specular reflection characteristic, and the electronic component has a diffuse reflection characteristic, the imaging polarization unit allows transmission of polarized light having the same polarization direction as the specific illumination polarized light that is specularly reflected by the holding surface in response to illumination of the specific illumination polarized light by the light illumination unit, and restricts transmission of non-polarized light that is diffusely reflected by the electronic component. The component mounter according to any one of claims 1 to 4, wherein the image acquisition unit is a camera in which an image sensor constituting the imaging unit and a polarizing filter constituting the imaging polarization unit are arranged side by side on an optical axis. The component mounter according to any one of claims 1 to 4, wherein the image acquisition unit is a polarization camera equipped with a polarizer stacked imaging element in which a polarizer constituting the imaging polarization unit is stacked on each pixel of an imaging element constituting the imaging 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;
7. 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.

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