JP3997967B2 - Image reading apparatus and image reading method in electronic component mounting apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus and an image reading method for reading an image for recognizing an electronic component in an electronic component mounting apparatus for mounting the electronic component on a substrate.

  Along with the advancement of the required position accuracy when mounting electronic components on a substrate, a method of correcting the positional deviation between the electronic component and the substrate during mounting by image recognition is widely used. In this method, in the middle of the path along which the transfer head that has picked up the electronic component from the component supply unit moves to the substrate, the transfer head passes above the camera disposed with the imaging surface facing upward, thereby causing the electronic component to move. Images are read.

  Since a large number of parts feeders are usually arranged in the component supply unit, the path through which the transfer head moves to the substrate differs depending on the parts feeder accessed by the transfer head. In the mounting operation in which the electronic component is transferred and mounted on the substrate by the movement of the transfer head, the length of the moving path of the transfer head greatly affects the tact time of the mounting operation. It is desirable that the camera be arranged so that the image can be read regardless of the path of the transfer head.

In order to realize such a request, a configuration in which line cameras are arranged over the entire width of the component supply unit has been proposed (see, for example, Patent Document 1). By adopting this configuration, when the transfer head picks up an electronic component from any part feeder of the component supply unit and moves it to the substrate, it reads the image of the electronic component with a line camera while passing through the shortest path. There is an advantage that can be.
Japanese Patent Laid-Open No. 5-55793

  However, in the above-described conventional example, since it is necessary to use a line sensor having a length that covers the entire width of the parts feeder arrangement range, the cost of the image reading apparatus increases. For this reason, the above-described example is difficult to apply to an electronic component mounting apparatus in which a large number of parts feeders are arranged.

  SUMMARY OF THE INVENTION Accordingly, the present invention provides an image reading apparatus and an image reading method in an electronic component mounting apparatus that can perform image reading of an electronic component without changing the moving path of the transfer head and can reduce the tact time of the mounting operation. The purpose is to provide.

An image reading apparatus in an electronic component mounting apparatus according to the present invention includes a substrate in which a plurality of parts feeders are picked up by a transfer head from a component supply unit in which a plurality of parts feeders are arranged in parallel along the substrate conveyance direction and positioned on the substrate positioning unit In the electronic component mounting apparatus that is transported and mounted on the electronic component mounting apparatus, the image reading device in the electronic component mounting apparatus that reads an image of the electronic component held by the transfer head from below by a line sensor, the component supply unit, the substrate positioning unit, A plurality of unit lens array structures arranged in a line at a predetermined pitch corresponding to the image capture width of the line sensor are arranged in series in the parallel arrangement direction of the parts feeder. The light is transmitted to each light receiving element of the line sensor by facing the lens array unit and the line sensor. A plurality of unit light transmission units arranged in parallel in a direction orthogonal to the light receiving element arrangement direction, the unit lens array structure and the unit light transmission unit are connected, and light incident from the lens is transmitted to the light transmission unit And a unit light transmission unit connected to a desired unit lens array structure by moving the line sensor relative to the light transmission unit in a direction orthogonal to the light receiving element arrangement direction. And a lens array switching means for transmitting light from a desired unit lens array structure to the line sensor.

  The image reading method in the electronic component mounting apparatus according to the present invention includes a substrate in which a plurality of parts feeders are picked up by a transfer head from a component supply unit in which a plurality of parts feeders are arranged in parallel along the substrate conveyance direction and positioned on the substrate positioning unit. In the electronic component mounting apparatus to be transported and mounted, the image reading method in the electronic component mounting apparatus for reading an image of the electronic component held by the transfer head from below by a line sensor, the electronic component mounting apparatus, A unit lens array structure that is arranged between the component supply unit and the substrate positioning unit and is configured by arranging a predetermined number of lens groups corresponding to the image capture width of the line sensor in a line at an equal pitch. A plurality of lens arrays arranged in series in a parallel arrangement direction of the feeder, and a line sensor by facing the line sensor A plurality of unit light transmission units that transmit light to each light receiving element are arranged in parallel in a direction orthogonal to the light receiving element arrangement direction, and the unit lens array structure and the unit light transmission unit are connected to each other to connect the lens. An optical transmission means for transmitting the light incident from the optical transmission section to the optical transmission section, and the line sensor is moved relative to the optical transmission section in a direction orthogonal to the light receiving element arrangement direction to connect to a desired unit lens array structure Lens unit switching means for transmitting light from a desired unit lens array structure to the line sensor by making the unit light transmission unit opposed to the line sensor, and in the image reading operation, the electronic component is transferred. The lens array switching means is switched according to a path along which the mounting head moves from the component supply unit to the substrate positioning unit, and an image of the electronic component is read.

  According to the present invention, a plurality of unit lens array structures configured by arranging a predetermined number of lens groups corresponding to the image capture width of the line sensor in a line at an equal pitch are arranged in series in the parallel arrangement direction of the parts feeder. The lens array unit is disposed between the component supply unit and the substrate positioning unit, and includes a lens array switching unit that transmits light from a desired unit lens array structure to the line sensor. The image reading of the electronic component can be performed without changing the movement path, and the tact time of the mounting operation can be shortened.

  Next, embodiments of the present invention will be described with reference to the drawings. 1 is a plan view of an electronic component mounting apparatus according to an embodiment of the present invention, FIG. 2 is a partial plan view of the electronic component mounting apparatus according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. 4 is a partial sectional view of the electronic component mounting apparatus, FIG. 4 is a perspective view of an imaging unit of the image reading apparatus according to the embodiment of the present invention, and FIG. 5 is a configuration of a control system of the electronic component mounting apparatus according to the embodiment of the present invention. FIG. 6 is a flowchart of the image reading method according to the embodiment of the present invention.

  First, the structure of an electronic component mounting apparatus in which the image reading apparatus of the present invention is incorporated will be described with reference to FIG. In FIG. 1, a transport path 2 is arranged in the X direction at the center of a base 1. The transport path 2 transports the substrate 3 and positions the substrate 3 at a predetermined position. Therefore, the conveyance path 2 is a substrate positioning part. On both sides of the transport path 2, component supply units 4 that supply electronic components are arranged. In each component supply unit 4, a plurality of parts feeders 5 are arranged along the X direction (substrate transport direction). The parts feeder 5 accommodates electronic components and supplies the electronic components to a transfer head described below.

Two Y-axis tables 6A and 6B are arranged in parallel at both end portions of the upper surface of the base 1, and X-axis tables 7A and 7B are installed on the Y-axis tables 6A and 6B, respectively. Transfer heads 8A and 8B are mounted on the X-axis tables 7A and 7B, respectively. The transfer heads 8A and 8B are multi-type transfer heads including a plurality of unit transfer heads 8a (see FIGS. 2 and 3). By driving the Y-axis table 6A and the X-axis table 7A, the transfer head 8A moves horizontally, and by driving the Y-axis table 6B and the X-axis table 7B, the transfer head 8B similarly moves horizontally. Each electronic component is picked up from the component supply unit 4 and transferred and mounted on the substrate 3 positioned in the substrate positioning unit.

  Between the component supply unit 4 and the conveyance path 2, lens array units 9 </ b> A and 9 </ b> B constituting an imaging unit for component recognition are arranged with an arrangement width substantially equal to the arrangement range of the parts feeder 5. The transfer heads 8A and 8B picked up by the transfer head 9 pass over the lens array units 9A and 9B when moving above the substrate 3 positioned in the transport path 2, thereby transferring the transfer head. Images of the electronic components held by the unit transfer heads 8a of 8A and 8B are read. The lens array units 9A and 9B include an illumination unit 10 that is movable in the X direction, and illumination light is irradiated from below onto the transfer heads 8A and 8B by the illumination unit 10 during image reading.

  Next, the imaging unit will be described with reference to FIGS. 2, 3, and 4. As shown in FIG. 4, the imaging unit includes a line sensor 13 in which light receiving elements 13a are arranged one-dimensionally, and the line sensor 13 has a direction in which the light receiving element arrangement direction is made to coincide with the X direction (substrate transport direction). Has been placed.

  Here, the image reading width W of the line sensor 13 is remarkably smaller than the arrangement range of the parts feeder 5 in the component supply unit 4, and if a single line sensor 13 is arranged as it is, an electronic component from any part feeder 5 can be used. The transfer heads 8A and 8B picking up the film cannot cover the moving path to move to the substrate 3. For this reason, in the image reading apparatus of the present embodiment, imaging light from an optical system composed of lens array portions 9A and 9B described below is guided to the line sensor 13 and is markedly greater than the image capture width W of the line sensor itself. A wide imaging range is obtained.

  As shown in FIGS. 2 and 4, the lens array units 9A and 9B are unit lens array structures 9a and 9b in which a predetermined number of lens groups corresponding to the image capture width W of the line sensor 13 are arranged in a line at an equal pitch. 9c are arranged in series in the parallel arrangement direction of the parts feeder 5. Each unit lens array structure forms an image of the electronic component held by the transfer heads 8A and 8B passing above by a small lens with a wide field of view.

  As shown in FIGS. 3 and 4, a light transmission unit 12 is disposed at a position facing the upper surface of the line sensor 13. The light transmission unit 12 has a configuration in which a plurality of unit light transmission units 12a, 12b, and 12c are arranged in a direction (Y direction) orthogonal to the light receiving element arrangement direction (X direction). Each unit light transmission unit has a structure in which light irradiation ports for irradiating light are arranged one-dimensionally corresponding to the light receiving element arrangement of the line sensor 13a. The line sensor 13 has a function of transmitting light to each light receiving element 13a.

  The unit light transmission units 12a, 12b, and 12c are connected to each other by light transmission means 16a, 16b, and 16c made of a light guide such as an optical fiber. The light transmission means 16a, 16b, and 16c are connected to the unit lens array structure 9a. , 9b, 9c are transmitted to the light irradiation ports of the unit light transmission units 12a, 12b, 12c corresponding to the one-dimensional arrangement positions of the lenses. The light from the light irradiation port is received by the respective light receiving elements 13a of the line sensors at the opposed positions, whereby a one-dimensional image of the electronic components held by the transfer heads 8A and 8B is acquired by the line sensor 13. Is done.

  Here, as shown in FIG. 3, the line sensor 13 is movable in the Y direction orthogonal to the light receiving element arrangement direction by a line sensor drive mechanism including a line sensor drive motor 14 and a feed screw 15. By driving the line sensor drive mechanism, the line sensor 13 is moved relative to the light transmission unit 12, and any of the unit light transmission units 12a, 12b, and 12c connected to the unit lens array structures 9a, 9b, and 9c. Can be selectively opposed to the line sensor 13.

  As a result, light from any one of the unit lens array structures 9a, 9b, and 9c can be transmitted to the line sensor 13. Therefore, the line sensor driving mechanism and the light transmission unit 12 serve as lens array switching means for transmitting light from a desired unit lens array structure to the line sensor 13.

  As shown in FIG. 2, the illumination unit 10 surrounds four light source sections 10a, 10b, 10c, and 10d in which light emitters such as LEDs are combined in a row, from four directions, corresponding to one unit lens array structure. The arrangement is as follows. The illumination unit 10 is movable in the X direction by a light source driving mechanism 11 (see FIG. 3). By driving the light source driving mechanism 11, any one of the unit lens array structures 9a, 9b, and 9c is illuminated. The unit 10 can be selectively moved.

  Next, the configuration of the control system will be described with reference to FIG. The control unit 20 performs overall control of each unit described below. The head movement position calculation unit 21 calculates linear movement paths of the transfer heads 8A and 8B when the electronic components are picked up from the component supply unit 4 by the transfer heads 8A and 8B and transferred and mounted on the substrate 3. This movement position calculation is calculated based on mounting data stored in advance, and when the transfer heads 8A and 8B pass over the lens array portions 9A and 9B, the unit lens array structures 9a, 9b, and 9c are calculated. It is determined which of the above passes, that is, which of the ranges A, B, and C shown in FIG. In the example shown in FIG. 2, this head movement position calculation specifies that the transfer heads 8A and 8B pass through the range A in the process of linear movement from the component supply unit 4 to the mounting point P on the substrate 3. The

  The line sensor movement position storage unit 22 stores a unit light transmission unit that is specified as a target to move the line sensor 13 during image reading based on the above calculation result. Similarly, the illumination unit movement position storage unit 23 stores the positions of the unit lens array structures 9a, 9b, and 9c that are the targets to which the illumination unit 10 is moved based on the calculation result. In the example shown in FIG. 2, the unit lens array structure 9 a corresponding to the range A is stored as a target for moving the line sensor 13 and a target for moving the illumination unit 10.

  The head drive unit 24 drives an X-axis motor 25, a Y-axis motor 26, a Z-axis motor 27, and a θ-axis motor 28 that constitute a moving mechanism that moves the transfer heads 8A and 8B. The line sensor drive unit 29 drives the line sensor drive motor 14 constituting the line sensor moving mechanism. The illumination unit drive unit 30 drives an illumination unit drive motor 31 for moving the illumination unit 10.

  This electronic component mounting apparatus is configured as described above. Next, an image reading method in the electronic component mounting operation will be described with reference to the flowchart of FIG. First, prior to the start of the mounting operation, the moving position of the transfer head, the lighting unit moving position, and the line sensor moving position are obtained and stored for each mounted component from the mounting data of the substrate to be mounted.

When the mounting operation is started, the transfer heads 8A and 8B first move to the component supply unit 4 and pick up electronic components from the parts feeder 5 designated by the mounting data (ST1). Next, the illumination unit 10 is moved to the movement position stored in advance in the illumination unit movement position storage unit 23, that is, to the position of the unit lens array structure corresponding to the movement path of the transfer heads 8A and 8B in the mounting operation (ST2). ).

  Then, the line sensor 13 moves according to the movement position stored in the line sensor movement position storage unit 22 (ST3). That is, the line sensor 13 is opposed to the unit light transmission unit connected to the unit lens array structure that is an image reading target during the mounting operation. Thereafter, the transfer heads 8A and 8B start to move to the substrate 3 (ST4), and component imaging is performed when the transfer heads 8A and 8B pass above the imaging unit (ST5). As a result, the images of the electronic components held by the transfer heads 8A and 8B are read, and the component positions held by the transfer heads 8A and 8B are recognized (ST6). Based on the component position recognition result, the electronic component is mounted on the board (ST7).

  That is, in the above-described image reading, the image of the electronic component is read by switching the lens array switching means according to the path along which the transfer heads 8A and 8B holding the electronic component move from the component supply unit 4 to the substrate positioning unit. I am doing so. Thereby, the image can be captured by the common line sensor 13 for the entire arrangement width of the parts feeder 5 in the component supply unit 4.

  Accordingly, during the movement of the transfer heads 8A and 8B from the component supply unit 4 to the substrate 3, the transfer heads 8A and 8B can move along the shortest path without changing the movement path for image reading for the purpose of component recognition. Furthermore, since the lens array portions 9A and 9B are extremely thin, the space between the component supply unit 4 and the conveyance path 2 can be minimized as compared with the case where an area sensor is used. The tact time can be shortened by minimizing the movement distance in the operation.

  Moreover, since the common line sensor 13 is used for the entire arrangement width of the parts feeder 5, the cost of the image reading apparatus can be reduced, and an electronic component for which an arrangement of a large number of parts feeders is planned. It can also be applied to mounting devices.

  The image reading apparatus and the image reading method in the electronic component mounting apparatus according to the present invention can read the image of the electronic component without changing the moving path of the transfer head, and can reduce the tact time of the mounting operation. It is useful for an electronic component mounting apparatus for mounting an electronic component on a substrate.

The top view of the electronic component mounting apparatus of one embodiment of this invention The fragmentary top view of the electronic component mounting apparatus of one embodiment of this invention The fragmentary sectional view of the electronic component mounting device of one embodiment of the present invention 1 is a perspective view of an imaging unit of an image reading apparatus according to an embodiment of the present invention. The block diagram which shows the structure of the control system of the electronic component mounting apparatus of one embodiment of this invention 1 is a flowchart of an image reading method according to an embodiment of the present invention.

Explanation of symbols

3 Substrate 4 Parts supply unit 5 Parts feeder 8A, 8B Transfer head 9A, 9B Lens array unit 9a, 9b, 9c Unit lens array structure 10 Illumination unit 12 Light transmission unit 12a, 12b, 12c Unit light transmission unit 13 Line sensor 16 Optical transmission means

Claims (2)

In the electronic component mounting apparatus, a plurality of parts feeders pick up an electronic component by a transfer head from a component supply unit arranged in parallel along the substrate conveyance direction, and transfer and mount it on the substrate positioned in the substrate positioning unit. An image reading apparatus in an electronic component mounting apparatus that reads an image of an electronic component held by a head from below by a line sensor,
A unit lens array structure that is arranged between the component supply unit and the substrate positioning unit and is configured by arranging a predetermined number of lens groups corresponding to the image capture width of the line sensor in a line at an equal pitch. A plurality of lens array units arranged in series in a parallel arrangement direction of feeders, and a unit light transmission unit that transmits light to each light receiving element of the line sensor by facing the line sensor in a direction orthogonal to the light receiving element arrangement direction A plurality of light transmission units arranged in parallel, a light transmission means for connecting the unit lens array structure and the unit light transmission unit and transmitting light incident from the lens to the light transmission unit, and the line sensor as the light transmission unit The unit light transmission unit connected to the desired unit lens array structure is opposed to the line sensor by relative movement in a direction orthogonal to the light receiving element array direction. More, the image reading apparatus in the electronic component mounting apparatus is characterized in that a lens array switching means for transmitting light from the desired unit lens array structure the line sensor. In the electronic component mounting apparatus, a plurality of parts feeders pick up an electronic component by a transfer head from a component supply unit arranged in parallel along the substrate conveyance direction, and transfer and mount it on the substrate positioned in the substrate positioning unit. An image reading method in an electronic component mounting apparatus for reading an image of an electronic component held by a head from below by a line sensor,
The electronic component mounting apparatus is arranged between the component supply unit and the board positioning unit, and is configured by arranging a predetermined number of lens groups corresponding to the image capturing width of the line sensor in a line at an equal pitch. A plurality of unit lens array structures arranged in series in the parallel arrangement direction of the parts feeder, and a unit light transmission unit that transmits light to each light receiving element of the line sensor by facing the line sensor A plurality of light transmission units arranged in parallel in a direction orthogonal to the arrangement direction, the light transmission means for connecting the unit lens array structure and the unit light transmission unit and transmitting light incident from the lens to the light transmission unit; A line sensor is moved relative to the light transmission unit in a direction orthogonal to the light receiving element arrangement direction, and the unit light transmission unit connected to a desired unit lens array structure is moved to the line sensor. By facing the sensor, and a lens array switching means for transmitting light from the desired unit lens array structure of a line sensor,
In the image reading operation, an electronic device is characterized in that the image of the electronic component is read by switching the lens array switching means according to a path along which the transfer head holding the electronic component moves from the component supply unit to the substrate positioning unit. An image reading method in a component mounting apparatus.

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