WO2018134862A1

WO2018134862A1 - Imaging device and surface mounting machine employing same

Info

Publication number: WO2018134862A1
Application number: PCT/JP2017/001312
Authority: WO
Inventors: 悠節小林; 鈴木　守
Original assignee: ヤマハ発動機株式会社
Priority date: 2017-01-17
Filing date: 2017-01-17
Publication date: 2018-07-26
Also published as: JPWO2018134862A1; JP6721716B2

Abstract

An imaging device includes an illumination device (64) for irradiating illumination light (L1 to L3) on a component (32), and a component imaging device (65) for imaging the component irradiated by the illumination light. The illumination device includes a base (71) having a flat surface, and a plurality of unit light sources (73) placed on the flat surface. The illumination device has an array structure with which at least an inside array unit (74b) and an outside array unit (74a) comprising an annular array group of a plurality of unit light sources are arrayed in concentric circle form on the flat plane. The amount of arriving light irradiated on the component by the illumination light (L2) emitted from the unit light sources (73) of the inside array unit (74b) and the amount of arriving light irradiated on the component by the illumination light (L1) emitted from the unit light sources (73) of the outside array unit (74a) are approximately the same.

Description

Imaging apparatus and surface mounter using the same

The present invention relates to an imaging device for imaging a component adsorbed by an adsorption nozzle for mounting the component on a substrate, and a surface mounter using the imaging device.

For example, Patent Document 1 discloses an imaging device that captures an image of a component (suction component) sucked by a suction nozzle from the lower side in a surface mounter. The imaging device includes an illumination device that irradiates illumination light to the suction component from below, and a component imaging device that receives reflected light from the suction component of the illumination light. In this type of illumination device, it is desirable to irradiate illumination light of an equal amount from the entire periphery of the suction component.

Patent Document 1 discloses an illumination device in which a plurality of unit light sources (LEDs) are arranged on a hemispherical base. Thereby, the distance with respect to the said adsorption | suction component of a some unit light source can be made substantially the same, and it can avoid that a big light quantity nonuniformity arises in the illumination light which illuminates each part of the said adsorption | suction component. However, the illumination device of Patent Document 1 has a three-dimensional shape because it requires a hemispherical base. For this reason, an arrangement space in the vertical direction is required, which becomes a factor that hinders downsizing of the lighting device and, consequently, downsizing of the surface mounter.

Japanese Patent No. 5798047

An object of the present invention is to provide an imaging device capable of reducing the thickness of an illumination light irradiation device for a suction component, and a surface mounter using the imaging device.

An imaging apparatus according to an aspect of the present invention is an imaging apparatus for a component adsorbed by an adsorption nozzle that mounts a component on a substrate, the illumination apparatus irradiating illumination light from below on the component, and the illumination light A component imaging device that images the irradiated component, and the illumination device includes a base having a plane perpendicular to a normal passing through the component sucked by the suction nozzle, and the illumination light disposed on the plane. A plurality of unit light sources that emit at least a part of the plurality of unit light sources arranged in a ring shape with the point at which the perpendicular intersects the plane when irradiated with the illumination light as an array center. An array structure in which an inner array section and an outer array section in which other portions of the plurality of unit light sources are arrayed in a ring shape outside the inner array section are arranged concentrically on the plane. A unit of the inner array part The amount of light reaching the component with the illumination light emitted from the source group is substantially the same as the amount of light reaching the component with the illumination light emitted from the unit light source group of the outer array section. .

A surface mounter according to another aspect of the present invention includes a head unit including a suction nozzle that mounts a component on a substrate, and the imaging device described above.

FIG. 1 is a plan view showing a schematic configuration of a surface mounter on which an imaging device (scan unit) according to an embodiment of the present invention is mounted. FIG. 2 is a side view showing a schematic configuration of a head unit portion of the surface mounter. FIG. 3 is a schematic cross-sectional view showing the configuration of the scan unit. FIG. 4 is a perspective view showing a specific example of the scan unit. FIG. 5 is a perspective view of the scan unit mounted on the head unit. FIG. 6 is a perspective view of the scan unit mounted on the head unit as seen from below. FIG. 7A is a plan view of the illumination unit according to the first embodiment. FIG. 7B is an enlarged view of an illuminating unit formed of an integrated unit light source of the illuminating unit shown in FIG. 7A. FIG. 8 is a schematic cross-sectional view along the optical axis of the illumination unit of the first embodiment. FIG. 9 is a schematic plan view of the illumination unit according to the first embodiment. FIG. 10 is a graph showing the light amount distribution of the illumination unit of the first embodiment. FIG. 11 is a schematic cross-sectional view illustrating an illumination unit according to a comparative example. FIGS. 12A to 12C are diagrams for explaining the cosine fourth power law relating to the decrease in the amount of light. FIG. 13 is a graph showing an example of a light distribution curve. FIG. 14 is a diagram for explaining advantages of the illumination unit of the first embodiment. FIG. 15 is a block diagram showing an electrical configuration of the surface mounter. FIG. 16 is a flowchart showing the operation of the surface mounter. 17A and 17B are diagrams illustrating examples of illumination patterns of the illumination unit. FIG. 18 is a diagram illustrating a preferable lighting control example of the illumination unit. FIG. 19 is a diagram for explaining the advantages of the lighting control of FIG. FIG. 20 is a schematic plan view of an illumination unit according to the second embodiment. FIG. 21A is a plan view of an illumination unit according to the second embodiment. FIG. 21B is an enlarged view of the illumination unit of the illumination unit shown in FIG. 21A.

[Overall structure of surface mounter]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view illustrating a schematic configuration of a surface mounter 1 to which an imaging apparatus according to an embodiment of the present invention is applied, and FIG. 2 is a side view illustrating a schematic configuration of a head unit 4 portion of the surface mounter 1. is there. The surface mounter 1 is a device for mounting various electronic components on a substrate P. In FIG. 1 and FIG. 2, XYZ direction indications are attached. In the following description, the X direction may be referred to as the left-right direction (the moving direction of the substrate P), the Y direction may be referred to as the front-rear direction, and the Z direction may be referred to as the up-down direction.

The surface mounter 1 includes a base unit 10, a substrate transport unit 2, a component supply unit 3 and a head unit 4 disposed on the base unit 10, a pair of substrate recognition cameras 5 mounted on the head unit 4 and a scan. And a unit 6 (imaging device). The board transport unit 2 transports the board P on which the electronic component 32 (see FIG. 3) is mounted. The component supply unit 3 supplies the electronic component 32 to be mounted. The head unit 4 takes out the electronic component 32 from the component supply unit 3 and mounts it on the substrate P.

The substrate transport unit 2 includes a pair of

conveyors

21 and 22 that transport the substrate P in the left-right direction on the base unit 10. The

conveyors

21 and 22 carry the board P into the surface mounter 1 from the right side in FIG. 1, transport it leftward to a predetermined work position (the position of the board P shown in FIG. 1), and temporarily stop it. At this working position, the electronic component 32 is mounted on the substrate P. A substrate support device (not shown) for supporting the substrate P with a backup pin during a mounting operation is disposed in a region below the work position. After the mounting operation, the

conveyors

21 and 22 convey the board P to the left and carry it out of the surface mounting machine 1 from the left side.

The component supply unit 3 is disposed on both sides in the front-rear direction of the substrate transport unit 2. Each component supply unit 3 includes a plurality of tape feeders 31 arranged in the left-right direction. Each tape feeder 31 holds a reel on which a tape on which small pieces of electronic components such as integrated circuits (ICs), transistors, resistors, and capacitors are stored and held at predetermined intervals is wound. The tape feeder 31 intermittently feeds the tape from the reel and supplies electronic components to the component supply position at the tip of the feeder.

The head unit 4 is disposed above the base portion 10 so as to be movable in the X and Y directions, takes out an electronic component from the tape feeder 31 at the component supply position, and mounts the electronic component at a predetermined position on the substrate P at the working position. . A support beam 23 extending in the X direction is provided above the base portion 10. The head unit 4 is movably supported by an X-axis fixed rail 24 fixed to the support beam 23. The support beam 23 is supported by a Y-axis fixed rail 25 whose both ends extend in the Y direction, and is movable along the Y-axis fixed rail 25 in the Y direction. An X-axis servo motor 26 and a ball screw shaft 27 are disposed with respect to the X-axis fixed rail 24, and a Y-axis servo motor 28 and a ball screw shaft 29 are disposed with respect to the Y-axis fixed rail 25. The head unit 4 moves in the X direction by the rotational drive of the ball screw shaft 27 by the X-axis servomotor 26, and moves in the Y direction by the rotational drive of the ball screw shaft 29 by the Y-axis servomotor 28.

The head unit 4 is equipped with a plurality of heads 41 for holding and transporting parts. In the present embodiment, an example in which a total of six heads 41 are arranged in a row in the X direction is shown. Each head 41 includes a drive shaft extending in the Z direction (up and down direction) and a suction nozzle 42 attached to the lower end of the drive shaft and sucking an electronic component. The suction nozzle 42 is connected to a negative pressure generating device (not shown) via an internal passage of the drive shaft and a switching valve (not shown). At the time of component suction, a negative pressure suction force is applied to the tip of the suction nozzle 42 from the negative pressure generating device, thereby making it possible to suck electronic components. Note that, when the component is mounted, the negative pressure suction force is eliminated, and the electronic component sucked by the suction nozzle 42 is released.

Each head 41 can be moved up and down with respect to the head unit 4 and rotated around the nozzle central axis (R axis). The head unit 4 includes an elevation drive mechanism and a rotation drive mechanism for the elevation and rotation of the head 41. The raising / lowering drive mechanism raises / lowers the head 41 between a lowered position when the electronic component is sucked or mounted and an elevated position when the electronic component is conveyed or imaged. The rotation drive mechanism is a mechanism for rotating the head 41 as necessary, and adjusts the posture of the electronic component by rotating the electronic component in the R-axis direction when mounting the component. These drive mechanisms are composed of a servo motor and a predetermined power transmission mechanism.

The board recognition camera 5 is fixedly mounted on both the left and right sides of the head unit 4, and various marks attached to the surface (upper surface) of the board P carried to the work position of the surface mounter 1 by the

conveyors

21 and 22. Image. In FIG. 1, as an example of the mark, a pair of fiducial marks FM attached on a diagonal line of a rectangular substrate P is shown. The fiducial mark FM is a mark for detecting a positional deviation amount with respect to the origin coordinates of the work position of the substrate P that has been loaded.

In the positional deviation detection work, the head unit 4 is driven in the XY directions so that the substrate recognition camera 5 can capture the pair of fiducial marks FM. The position of the fiducial mark FM is specified on the image data obtained by imaging, and a positional deviation amount with respect to the origin coordinates is obtained. This positional deviation amount is referred to at the time of component mounting, and the electronic component is mounted on the board P so that the positional deviation does not occur.

The scan unit 6 is mounted in the vicinity of the lower end of the head unit 4 so as to be movable in the X direction (arrangement direction of the suction nozzles 42) with respect to the head unit 4, and the electronic component 32 sucked by the suction nozzles 42 (FIG. 3). ). The scan unit 6 is a unit for recognizing an image of the suction state of the electronic component 32 by the suction nozzle 42. The scan unit 6 performs a predetermined imaging operation while the head unit 4 is transporting the electronic component 32 sucked by the suction nozzle 42 from the component supply position to the work position.

In this imaging operation, the scan unit 6 images the electronic component 32 sucked by the suction nozzle 42 from the lower surface side while moving in the X direction along the ball screw shaft 61 attached to the head unit 4 and extending in the X direction. To do. On the image data obtained by imaging, the amount of deviation between the center position of the electronic component 32 and the reference position of the suction nozzle 42 (the amount of positional deviation in the X-axis and Y-axis directions) and the amount of rotational deviation in the R-axis direction are detected. Is done. These deviation amounts are referred to at the time of component mounting, the moving position of the head unit 4 is corrected according to the positional deviation amount, and the head 41 is rotated to be corrected according to the rotational deviation amount, so that the electronic component 32 can accurately detect the substrate P. It is mounted at a predetermined mounting position.

[Scan Unit]
FIG. 3 is a schematic cross-sectional view showing the configuration of the scan unit 6. The moving frame 60 of the scan unit 6 receives the illumination unit 64 (illumination device) that irradiates the electronic component 32 with illumination light L from below and the reflected light R of the electronic component 32 irradiated with the illumination light L. A component recognition camera 65 (component imaging device) that captures an image of the component 32 is provided. The imaging optical axis Q of the component recognition camera 65 is along the reflected light R.

The moving frame 60 is a member that moves in the X direction along the above-described ball screw shaft 61, and includes a base block 62 and a facing portion 63. The base block 62 includes an upper part along the rear side of the head unit 4 and a lower part protruding downward from the lower surface of the head unit 4. A nut member 621 that is screwed onto the ball screw shaft 61 is provided on the upper part. It has. By the normal rotation or reverse rotation of the ball screw shaft 61, the moving frame 60 moves in the X direction. The component recognition camera 65 is disposed in the lower part. In addition, although the moving mechanism of the moving frame 60 using the ball screw shaft 61 is illustrated here, other moving mechanisms, for example, a moving mechanism of the moving frame 60 using a linear motor may be employed.

The facing portion 63 extends horizontally from the lower end of the base block 62 and is positioned below the head unit 4. The facing portion 63 is a portion that holds the illumination unit 64 in the moving frame 60 and moves in the X direction (the arrangement direction of the suction nozzles 42) below the suction nozzle 42. The facing portion 63 is formed with a cylindrical recessed portion 631 that is a recessed portion opened on the upper surface side, and a tunnel portion 632 extending in the Y direction from the side wall surface of the recessed portion 631. A prism 633 is disposed in the recess 631. The tunnel portion 632 is a space for forming an optical path (imaging optical axis Q) between the concave portion 631 and the objective lens portion of the component recognition camera 65. The reflected light R of the electronic component 32 enters the concave portion 631 and is reflected by the prism 633, is guided by the tunnel portion 632, and enters the component recognition camera 65.

The illumination unit 64 includes a flat illumination unit substrate 71 (base) and a plurality of unit light sources 73 arranged concentrically on the illumination unit substrate 71. As the unit light source 73, for example, a white LED that emits white light is used. The illumination unit substrate 71 has an upper surface 71U that is a plane orthogonal to the perpendicular V passing through the electronic component 32 sucked by the suction nozzle 42. The perpendicular V is also a line parallel to the movement axis of the head 41 that moves forward and backward in the Z direction. The unit light source 73 is mounted on the upper surface of the illumination unit substrate 71 and emits illumination light L that irradiates the electronic component 32. The plurality of unit light sources 73 are arranged annularly and concentrically with the point a where the perpendicular V intersects the upper surface 71U as the center of arrangement.

The component recognition camera 65 is assembled at an appropriate position of the moving frame 60 and captures an image of the lower surface of the electronic component 32 sucked by the suction nozzle 42 under illumination by the illumination unit 64. The component recognition camera 65 includes a line sensor 651 in which pixels composed of a CCD image sensor or the like are arranged in a line, and a condensing lens (not shown). The reflected light R described above is imaged on the light receiving surface of the line sensor 651 through the condenser lens to form a line image. As the moving frame 60 moves in the X direction, the electronic component 32 is scanned, and an image of the electronic component 32 is generated by combining the line images.

[Specific example of scan unit]
Next, an example of a specific configuration of the above-described scan unit 6 will be shown. FIG. 4 is a perspective view showing a specific example of the scan unit 6. FIG. 5 is a perspective view of the scan unit 6 mounted on the head unit 4, and FIG. 6 is a perspective view of the scan unit 6 viewed from below. The basic configuration of the scan unit 6 is the same as that described above with reference to FIG. 3, and includes the illumination unit 64 and the component recognition camera 65 mounted on the moving frame 60. FIG. 4 shows an example in which a second prism 634 that further bends the optical path is provided in addition to the prism 633.

As shown in FIG. 6, a support block 44 is disposed on the back side of the array of heads 41, and a guide rail 45 extending in the X direction is provided on the lower surface of the support block 44. The moving frame 60 has an engaging portion with respect to the guide rail 45, and moves in the X direction by driving the camera shaft servomotor 43 (FIG. 15).

[First Embodiment of Lighting Unit]
<Arrangement of unit light sources>
FIG. 7A is a plan view of the illumination unit 64 according to the first embodiment shown in FIGS. The illumination unit 64 includes an illumination unit substrate 71 and an illumination unit 72 (illumination device). The illumination unit substrate 71 is a printed circuit board on which a plurality of unit light sources 73 can be mounted, and has an upper surface 71U serving as a mounting surface. The upper surface 71U is a plane that is substantially free of unevenness, and is a plane that is orthogonal to the perpendicular V (FIG. 3) passing through the electronic component 32 sucked by the suction nozzle 42 as described above with reference to FIG. is there. The illuminating unit 72 is composed of an integrated body of unit light sources 73 in which a plurality of unit light sources 73 are arranged concentrically.

The illumination unit substrate 71 is a rectangular substrate that is long in the Y direction. A bulging portion 711 whose width in the X direction is partially expanded is provided slightly forward of the center of the lighting unit substrate 71 in the Y direction. An illumination unit 72 is disposed on the bulging portion 711. In addition, a slit 712 that penetrates the illumination unit substrate 71 in the Z direction is perforated near the center in the X direction at the position where the bulging portion 711 is disposed. The slit 712 is a rectangular opening that is long in the Y direction, and is an opening that matches the pixel arrangement direction of the line sensor 651. The imaging optical axis Q of the component 32 passes through the slit 712 and reaches the component recognition camera 65. The slit 712 is provided at a position that is vertically below the suction nozzle 42. The reflected light R from the electronic component 32 sucked by the suction nozzle 42 passes through the slit 712 and is guided to the component recognition camera 65.

FIG. 7B is an enlarged view of the illumination unit 72 shown in FIG. 7A. The illuminating unit 72 is formed by arranging an annular array of a plurality of unit light sources 73 in 10 layers in the radial direction. A first array portion 74A in which a plurality of unit light sources 73 (a part of the plurality of unit light sources) are arranged in an annular shape at a predetermined pitch is disposed on the outermost side in the radial direction. The annular array center is the center of the bulging portion 711 in the X direction, that is, the center of the slit 712. That is, the illumination unit substrate 71 has a slit 712 as an opening around the array center. The arrangement center is a point a where a perpendicular V passing through the electronic component 32 intersects the upper surface 71U of the illumination unit substrate 71 when the illumination light L is irradiated to the electronic component 32 to be imaged. In the present embodiment, an example is shown in which the unit light sources 73 in the first arrangement portion 74A are arranged in a hexagonal ring shape (which can be approximated to an annular shape) advantageous for high-density arrangement. Instead of this, for example, the unit light sources 73 may be arranged in an annular shape.

Similarly, a second array portion 74B (inner array portion with respect to the first array portion 74A) in which the unit light sources 73 are arrayed in a hexagonal ring shape is disposed on the radially inner side of the first array portion 74A (outer array portion). Has been. Furthermore, on the inner side in the radial direction of the second array portion 74B, a third array portion 74C, a fourth array portion 74D, a fifth array portion 74E, and a sixth array portion 74F that are composed of a hexagonal annular array group of unit light sources 73 in sequence. The seventh arrangement unit 74G, the eighth arrangement unit 74H, the ninth arrangement unit 74I, and the tenth arrangement unit 74J are arranged. Note that the tenth array portion 74J at the innermost radial direction is not annular, and is composed of only a pair of unit light sources 73 arranged with the slit 712 interposed therebetween. The illumination unit 72 has a structure in which the first to tenth arrangement parts 74A to 74J (inner arrangement part and outer arrangement part) are arranged around the slit 712, that is, concentrically centering on the arrangement center. It has an arranged arrangement structure.

In the first to ninth arrangement portions 74A to 74I, the unit light sources 73 are arranged in a hexagonal ring shape. Therefore, the arrangement group of these unit light sources 73 includes six triangular blocks arranged in the circumferential direction, that is, The block is divided into a block 75A, a second block 75B, a third block 75C, a fourth block 75D, a fifth block 75E, and a sixth block 75F. The number of unit light sources 73 arranged in the second block 75B and the fifth block 75E arranged in the X direction that is the moving direction of the illumination unit 72 is the first and

second arrangement parts

74A and 74B = 6, respectively. 3rd arrangement part 74C = 5, 4th,

5th arrangement part

74D, 74E = 4, 6th,

7th arrangement part

74F, 74G = 3, 8th, 9th arrangement part 74H, 74I = 2 , Tenth array portion 74J = 1. In the arrangement portion having the same arrangement number, the arrangement pitch of the unit light sources 73 is set shorter in the inner arrangement portion than in the outer arrangement portion. In the fourth arrangement portion 74D, one unit light source 73 is disposed so as to straddle the boundary portions of the first and

sixth blocks

75A and 75F and the boundary portions of the third and

fourth blocks

75C and 75D. ing.

<The amount of light emitted by each array>
In the first embodiment, the unit light source 73 of the illumination unit 72 does not emit the same amount of illumination light, but is controlled so that the light amount of the unit light source 73 differs in units of the first to tenth array units 74A to 74J. . That is, the units of the array units 74A to 74J are set so that the amount of light that is emitted from the unit light sources 73 of the first to 10th array units 74A to 74J is irradiated to the electronic components 32 is substantially the same. The light quantity of the light source 73 is controlled.

The light quantity control will be described based on a simplified model of the illumination unit 72. FIG. 8 is a schematic cross-sectional view of the illumination unit 72 according to the first embodiment along the optical axis, and FIG. 9 is a plan view of the illumination unit 72. Here, an example in which the first array portion 74a, the second array portion 74b, and the third array portion 74c, which are formed of an annular array of unit light sources 73, are arranged concentrically from the radially outer side to the inner side in this order. Simplified. The center of this concentric circle passes directly under the center of the electronic component 32. Here, in the relationship between the first array portion 74a and the second and

third array portions

74b and 74c, the former is the outer array portion and the latter is the inner array portion. The second array portion 74b is an outer array portion in relation to the third array portion 74c.

The unit light sources 73 of the first to third arrangement portions 74a to 74c are arranged on a plane (illumination unit substrate 71). Each unit light source 73 is mounted on the illumination unit substrate 71 such that its optical axis is directed in the vertical direction of the illumination unit substrate 71. What the line sensor 651 of the component recognition camera 65 captures is a line-shaped optical image of the reflected light R from the imaging point 32 </ b> A on the lower surface of the electronic component 32. Illumination lights L1, L2, and L3 emitted from the first, second, and

third arrangement portions

74a, 74b, and 74c reach the imaging point 32A. These illumination lights L1, L2, and L3 are light beams having directivity angles θ1, θ2, and θ3 with respect to the optical axis among the light beams emitted from each unit light source 73. Therefore, when all the unit light sources 73 of the first to third arrangement units 74a to 74c emit light with the same light amount, the amount of light reaching the imaging point 32A is illumination light L1 <L2 <L3.

That is, the illumination light L1 emitted from the first array portion 74a at the outermost radial direction has a longer optical path length with respect to the imaging point 32A than L2 and L3, and the directivity angle θ1 with respect to the optical axis also increases. The further to the inner side in the radial direction, the shorter the optical path length, and the directivity angle becomes θ1> θ2> θ3. Therefore, the amount of light reaching the imaging point 32A of the illumination light L1 is the smallest. For this reason, if the unit light sources 73 of the first to third arrangement portions 74a to 74c are caused to emit light with the same light amount, it is not possible to irradiate the electronic component 32 with uniform illumination light from different illumination angles. Therefore, it is necessary to devise a light amount distribution of the illumination unit 72.

FIG. 10 is a graph showing the light amount distribution of the illumination unit 72 of the first embodiment. A light amount distribution A1 in FIG. 10 is a comparative example, and is a light amount distribution when all the unit light sources 73 of the illumination unit 72 emit light with the same light amount. With such a light amount distribution A1, it is difficult to uniformly illuminate the electronic component 32 as described above. On the other hand, the light amount distribution A2 indicates the light amount distribution of the illumination unit 72 of the first embodiment. In the light amount distribution A2, the light amount on the radially outer side protrudes and is high, and the light amount on the radially inner side is smaller than this. With such a light amount distribution A2, the amount of light reaching the imaging point 32A can be set to illumination light L1≈L2≈L3. In other words, the amount of light reaching the electronic component 32 with the illumination lights L1 to L3 emitted from the unit light sources 73 of the first to third arrangement portions 74a to 74c can be made substantially the same.

FIG. 11 is a schematic cross-sectional view showing an illumination unit according to a comparative example. Conventionally, in order to make the amount of light reaching the electronic component 32 substantially the same, an illumination unit substrate 71A that is concavely curved in a hemispherical shape is used as shown in FIG. By using such an illumination unit substrate 71A, the unit light sources 73 can be arranged radially with respect to the electronic component 32, and the optical path lengths can be made substantially the same. Therefore, even if all the unit light sources 73 emit light with the same light amount, the reaching light amount can be made substantially the same.

However, since a hemispherical illumination unit substrate 71A is required, it is necessary to secure an arrangement space in the Z direction, which becomes a factor that hinders downsizing of the illumination unit 64 and, consequently, downsizing of the surface mounter 1. On the other hand, according to the illumination unit 64 of the present embodiment, since the unit light source 73 is mounted on the illumination unit substrate 71 made of a flat plate, the size of the illumination unit 64 in the Z direction can be minimized. .

[Preferred light intensity control mode]
As described above, the white light emitting LED is preferably used as the unit light source 73 in the present embodiment. As this LED, an LED having a shell-type mold layer can be used, but a surface-mounted chip LED is preferable because it can be highly integrated and mounted on the illumination unit substrate 71 and has excellent heat dissipation. A surface-mount type chip LED generally has a structure in which an LED arranged in a package member is sealed with a transparent resin mold layer, and does not have a light distribution directivity like a shell-type LED, and has a Lambertian distribution. It can be treated approximately as a light source having light (Lambert light source).

The cosine power law should be considered when using a Lambertian light source. In the case of a light source that radiates light radially like a Lambert light source, the amount of light (illuminance) directed in the direction of the directivity angle θ with respect to the optical axis (directivity angle θ = 0 °) is proportional to cos ⁴ θ. As a result, the amount of light decreases (cosine fourth power rule).

FIGS. 12A to 12C are diagrams for explaining the cosine fourth power law relating to the decrease in the amount of light. FIG. 12A is a diagram illustrating the relationship between the light amount and the distance. Here, an optical model in which a light beam B1 on the optical axis and a light beam B2 having a directivity angle of θ with respect to the optical axis are imaged on the imaging surface 12 through the imaging lens 11 at a focal length f is handled. In general, the amount of light decreases in inverse proportion to the square of the distance. That is, as the distance increases, the area illuminated with the same light flux increases, so the amount of light per unit area decreases to 1 / square of the distance. Therefore, in the case of a Lambertian light source, the light amount of the light beam B2 having the directivity angle of the angle θ is proportional to cos ² θ.

FIG. 12 (B) is a diagram showing a light amount reduction factor due to oblique incidence on the imaging surface 12. The amount of light irradiated per unit area varies depending on the incident angle to the image plane 12. In the case of the light beam B1 on the optical axis, the spot 13 formed on the image plane 12 is circular. However, in the case of the light beam B2 having a directivity angle of θ with respect to the optical axis, the spot 14 formed on the image plane 12 is elliptical. Since the elliptical spot 14 has a larger area than the circular spot 13, the amount of light irradiated per unit area is smaller in the elliptical spot 14. That is, it is proportional to cos θ.

Further, FIG. 12C is a diagram showing the relationship between the width of the imaging lens 11 and the oblique incidence. As shown by the arrow h in FIG. 12B, the light quantity of both is the same when viewed in a cross section orthogonal to the light beams B1 and B2. However, since the imaging lens 11 has a finite width, the light beam B2 having a directivity angle of θ relative to the optical axis can pass only the width of the imaging lens 11. For this reason, when the imaging lens 11 is circular, the cross section 15 after passing through the lens is circular in the light ray B1, but the cross section 16 after passing through the lens is thinly elliptical in the light ray B2.

As described above, when the factors shown in FIGS. 12A to 12C are multiplied, the amount of light decreases in proportion to cos ⁴ θ. FIG. 13 is a graph showing a model of a light distribution curve. A light distribution curve C1 in FIG. 13 is a light distribution curve in which the amount of light decreases in proportion to cos θ. On the other hand, the light distribution curve C2 is a light distribution curve in which the amount of light decreases in proportion to cos ⁴ θ, and models the light amount reduction characteristics of the obliquely incident light beam B2 in FIGS. is there. In the case of a light beam having a directivity angle of 0 °, there is no difference in the amount of light reduction between the light distribution curves C1 and C2. However, in the case of a light beam having a directivity angle = θ, the light amount decreases in proportion to cos ⁴ θ on the light distribution curve C2. For this reason, the intersection D1 with the light distribution curve C1 and the intersection D2 with the light distribution curve C2 are greatly deviated.

In order to compensate for such a decrease in the amount of light, the amount of light may be increased in proportion to cos ⁴ θ according to the arrangement position of the unit light sources 73. Thereby, the electronic component 32 can be uniformly illuminated from various directivity angles. If the example of FIG. 8 is used, the unit light sources 73 of the first array unit 74a (θ1), the second array unit 74b (θ2), and the third array unit 74c (θ3) are different from each other in the light amount OP1 (second light amount). It is assumed that light is emitted with the light amount OP2 (first light amount) and the light amount OP3. The magnitude of the light quantity is OP1>OP2> OP3. Further, the light amount OP1 is set based on 1 / cos ⁴ θ1, the light amount OP2 is set based on 1 / cos ⁴ θ2, and the light amount OP is set based on 1 / cos ⁴ θ3. In this way, cos ⁴ the amount of the unit light source 73 the light amount is disposed at a position to be lowered in proportion to .theta.1 ~ .theta.3, by setting, based on the inverse of cos ⁴ θ1 ~ θ3 respectively, illumination light L1, L2 The amount of light reaching the electronic component 32 of L3 can be made substantially the same.

The reason why the reaching light amounts of the illumination lights L1 to L3 are “substantially the same” is that it is substantially difficult to make these reaching light amounts exactly the same. Further, even if there is a slight difference in the amount of light reaching these, the electronic component 32 sucked by the suction nozzle 42 can be in a substantially illuminated state. For example, when the amount of light reached by the other array part (for example, the third array part 74c) differs within a range of about ± 20% with respect to the amount of light reached by one array part (for example, the first array part 74a), Even if the difference is preferably within a range of about ± 10%, it is within the category of “substantially the same” as used in this specification.

FIG. 14 is a diagram for explaining the advantages of the illumination unit 72 of the first embodiment. By making the amount of illumination light L1, L2, L3 reaching the electronic component 32 substantially the same, the lower surface of the electronic component 32 can be illuminated uniformly. Thereby, the recognition stability and accuracy of the electronic component 32 are improved. In particular, as in the case of the electronic component 32 shown in FIG. 14, this is effective when the curved surface portion 32R is provided on the lower surface side. The curved surface portion 32R is a curved surface having curved

lower end portions

321 and 322 on the lower surface of the electronic component 32 and curved

upper end portions

323 and 324 on the side surfaces at both ends in the relative movement direction of the illumination unit 64, respectively.

In this case, if the amount of the illumination light L1 is small, the edge of the curved surface portion 32R may not be recognized. Specifically, the curved

upper end portions

323 and 324 tend to be difficult to recognize on the image acquired by the component recognition camera 65. In this case, the width of the electronic component 32 is recognized as between the curved

lower end portions

321 and 322 and is erroneously recognized to be smaller than the actual width of the electronic component 32. On the other hand, when the amount of the illumination light L1 is substantially the same as that of the illumination lights L1 and L2, the edges of the curved upper ends 323 and 324 on the side surfaces can be easily recognized on the image. Therefore, the width of the electronic component 32 can be accurately recognized.

[Electrical configuration of surface mounter]
Next, the control configuration of the surface mounter 1 will be described. FIG. 15 is a block diagram showing an electrical configuration of the surface mounter 1. The surface mounter 1 includes a control unit 8 that controls the operation of each unit of the surface mounter 1. The control unit 8 controls operations of the head unit 4, the substrate recognition camera 5, the scan unit 6 and the like described above by executing a predetermined program. The block diagram of FIG. 15 shows a camera axis servo motor 43 that moves the moving frame 60 (the illumination unit 64 and the component recognition camera 65) in the X direction, which is not shown in FIGS. Yes. As described above, a linear motor may be employed instead of the camera shaft servomotor 43.

The control unit 8 functionally includes a camera control unit 81, an illumination control unit 82 (light quantity control unit / lighting control unit), an image processing unit 83, an axis control unit 84, a main control unit 85, and a storage unit 86.

The camera control unit 81 controls the imaging operation of the board recognition camera 5 and the component recognition camera 65 of the scan unit 6. For example, the camera control unit 81 controls the shutter timing and shutter speed (exposure amount) of the

cameras

5 and 65.

The illumination control unit 82 controls the light emission operation of the illumination unit 72 (unit light source 73) included in the illumination unit 64. The illumination control unit 82 emits illumination light emitted from a group of unit light sources 73 provided in at least the first to ninth arrangement units 74A to 74I (first to third arrangement units 74a to 74c in the case of the schematic diagram of FIG. 9). However, the light emission amounts of the unit light sources 73 of the array portions 74A to 74I are controlled so that the amount of light reaching each of the electronic components 32 is substantially the same. For example, in the relationship between the first array unit 74A (outer array unit) and the fifth array unit 74E (inner array unit), illumination light (second light amount) emitted from the group of unit light sources 73 of the first array unit 74A. So that the amount of light that reaches the electronic component 32 and the amount of light that the illumination light (first light amount) emitted from the group of unit light sources 73 of the fifth array unit 74E irradiates the electronic component 32 are substantially the same. The illumination control unit 82 controls the light emission amount of each unit light source 73. That is, the illumination control unit 82 controls the light emission amount of the unit light source 73 so that the light quantity distribution A2 shown in FIG. 10 is obtained. When the unit light source 73 is an LED having a Lambertian light distribution, the illumination control unit 82 determines the unit light source based on the relationship of 1 / cos ⁴ θ according to the arrangement positions of the first to ninth arrangement units 74A to 74I. The amount of emitted light 73 is controlled.

The image processing unit 83 applies an image processing technique such as edge detection processing or pattern recognition processing with feature amount extraction to the recognition images acquired by the board recognition camera 5 and the component recognition camera 65, and uses the recognition images. Extract various information. Specifically, the image processing unit 83 performs processing for specifying the position of the fiducial mark FM based on the recognition image acquired by the board recognition camera 5. Further, the image processing unit 83 performs processing for specifying the shape, position, and the like of the electronic component 32 based on the recognition image acquired by the component recognition camera 65.

The axis control unit 84 controls the movement operation of the head unit 4 in the X and Y directions by controlling the X axis servo motor 26 and the Y axis servo motor 28. Further, the axis control unit 84 controls the elevation and rotation operations of the head 41 by controlling the elevation drive mechanism and the rotation drive mechanism (not shown) included in the head unit 4. Further, the axis control unit 84 controls the camera axis servo motor 43 to control the movement of the scan unit 6 (moving frame 60) in the X direction along the lower surface of the head unit 4.

The main control unit 85 comprehensively controls various operations on the surface mounter 1. For example, when scanning the image of the electronic component 32 sucked by the suction nozzle 42 by the scan unit 6, a control signal is given to the axis control unit 84, the camera control unit 81, and the illumination control unit 82, and the scan unit 6 is set to X While moving in the direction, the illumination unit 64 irradiates the electronic component 32 with illumination light and causes the component recognition camera 65 to capture an image of the electronic component 32.

The storage unit 86 stores various information related to the substrate P and the electronic component 32. The information regarding the electronic component 32 is, for example, the type or attribute information of the electronic component. Examples of the electronic component include a chip component such as a chip resistor, a ball component such as BGA (Ball Grid Array), and a leaded component such as QFP (Quad Flat Package) and SOP (Small Outline Package). In the case of the leaded component, the storage unit 86 stores information such as the number and arrangement of leads and the height position of the lead tip.

[Operation flow of surface mounter]
FIG. 16 is a flowchart showing the basic operation of component mounting in the surface mounter 1. First, under the overall control of the main control unit 85, the axis control unit 84 controls the X-axis servo motor 26 and the Y-axis servo motor 28 to move the head unit 4 to the component supply position (step S1). The component supply position is, for example, the tip portion of the tape feeder 31 of the component supply unit 3. Next, the head 41 is lowered by the lifting drive mechanism provided in the head unit 4, and a negative pressure suction force is applied to the tip of the suction nozzle 42 by a negative pressure generator (not shown), so that the electronic component 32 is sucked ( Step S2).

The main control unit 85 checks whether or not there is another electronic component 32 that is scheduled to be sucked, in other words, whether or not the electronic component 32 is picked up by all the suction nozzles 42 included in the head unit 4. (Step S3). If there is another electronic component 32 to be picked up (YES in step S3), the process returns to step S1. On the other hand, when there is no other electronic component 32 to be picked up (NO in step S3), the axis control unit 84 starts moving the head unit 4 toward the component mounting position on the substrate P (step S4).

When the head unit 4 moves, image recognition of each electronic component 32 sucked by each suction nozzle 42 is executed. The axis control unit 84 controls the camera axis servo motor 43 to move the scan unit 6 in the X direction. After the movement is started, the illumination control unit 82 determines the amount of light to turn on each unit light source 73 of the illumination unit 64 according to the sucked component 32. The light quantity of each unit light source 73 is determined so that the light quantity distribution as shown in FIG. 10 is obtained for the illumination unit 64 as a whole (step S5). Then, the illumination control unit 82 turns on the unit light source 73 with the light amount determined in step S5, and the camera control unit 81 operates the component recognition camera 65 to display an image of the electronic component 32 irradiated with the illumination light. It is made to acquire (step S6). The acquired image data is temporarily stored in the storage unit 86 and given to the image processing unit 83.

Image processing is performed by the image processing unit 83 and the shape of the electronic component 32 is recognized. The main control unit 85 calculates the component center position of the sucked electronic component 32 based on the obtained component shape, suction posture, and the like (step S7). Further, the main controller 85 compares the reference position, which is the theoretical component center position when the electronic component 32 is normally attracted to the suction nozzle 42, with the component center position calculated in step S7, A correction value at the time of mounting is derived (step S8). This correction value is temporarily stored in the storage unit 86.

Thereafter, the main control unit 85 confirms whether or not there is an image of the electronic component 32 that has been obtained elsewhere. That is, it is determined whether correction values have been calculated for all the electronic components 32 sucked by the plurality of suction nozzles 42 (step S9). If there is an image of another electronic component 32 (YES in step S9), the process returns to step S6 and the same processing is executed for the other electronic component 32.

On the other hand, when there is no other image of the electronic component 32 (NO in step S9), the axis control unit 84 moves the head unit 4 to the component mounting position of the electronic component 32 in which the mounting order is set to the first. (Step S10). And the said 1st electronic component 32 is mounted in the predetermined position of the board | substrate P (step S11). The main control unit 85 determines whether there is another electronic component 32 that is scheduled to be mounted (step S12). If another electronic component 32 to be mounted remains in the suction nozzle 42 (YES in step S12), the process returns to step S10 to continue component mounting. If there is no other electronic component 32 to be mounted (NO in step S12), the process ends.

[About lighting pattern]
The illumination unit 72 of the illumination unit 64 can be lit with a predetermined illumination pattern according to the type of electronic component 32, the surface state, and the terminal and lead modes. 17A and 17B are diagrams illustrating examples of illumination patterns of the illumination unit 72. FIG. In FIGS. 17A and 17B, a relatively dark portion is a portion to be lit.

FIG. 17A is an example of an illumination pattern in the “center mode”. In the “center mode”, all the unit light sources 73 of the annular array portion are turned on except for the unit light sources 73 of the annular array portion located on the outermost periphery. According to the example of the first to tenth array portions 74A to 74J shown in FIG. 7B, the second to tenth array portions 74B to 74J are to be turned on, and only the first array portion 74A is not turned on. .

FIG. 17B is an example of an illumination pattern in the “outer ring mode”. In the “outer ring mode”, only the unit light sources 73 of the annular array portion located on the outermost periphery are turned on, and the unit light sources 73 of the remaining annular array portions are turned off. According to the example of FIG. 7B, only the first array portion 74A is a lighting target, and the second to tenth array portions 74B to 74J are not lighted. Instead of this, the first and

second arrangement portions

74A and 74B may be the lighting target.

In addition, the “all-lamp mode” in which the unit light sources 73 of all the annular array portions are turned on, the coaxial illumination unit (not shown) is used to illuminate the electronic component 32 from the imaging optical axis of the component recognition camera 65 There is a “coaxial mode” in which only the light source that emits light is turned on. A combination mode of the “coaxial mode” and the “outer ring mode” and a combination mode of the “coaxial mode” and the “center mode” can also be employed.

The “center mode” in FIG. 17A is exclusively used for component recognition such as QFP and SOP where the part other than the lead part is a mirror surface. The “outer ring mode” in FIG. 17B is used for recognizing a ball component such as a BGA. This is because if the ball part is irradiated with illumination light only from the annular array part on the outer periphery, only the outer periphery of the ball part shines and it is easy to recognize the ball shape. The above "coaxial mode" is used for recognition of parts whose lead part is a mirror surface, and the combination mode of "coaxial mode" and "center mode" is used when recognizing the entire lower surface of parts such as chip parts, QFP, SOP, etc. Is done. The “all-light mode” or the combination mode of “coaxial mode” and “outer ring mode” is used when it is necessary to recognize the edge of a transparent component (such as a lens) and to determine the direction of a ball component such as a BGA.

In the above-mentioned “center mode”, “all-lamp mode”, and the combination mode of “center mode” and “coaxial mode”, the illumination control unit 82 makes the illumination unit 72 obtain the light amount distribution A2 shown in FIG. The light amount of the unit light source 73 of each of the array units 74A to 74J is controlled. In the “outer ring mode”, the illumination control unit 82 causes the unit light sources 73 of the first arrangement unit 74A to emit light with a predetermined light amount.

[Partial light extinction control of lighting section]
In the present embodiment, the component recognition camera 65 includes a line sensor 651, and the electronic unit 32 is moved relative to the lower side of the electronic component 32 sucked by the suction nozzle 42 in the scanning direction (X direction). Get the image. For this reason, when the scan unit 6 moves, a part of the illumination light emitted from the unit light source 73 of the illumination unit 72 may be reflected by the suction nozzle 42 instead of the electronic component 32 and may enter the slit 712. When such reflected light is incident, the image of the component is deteriorated and the accuracy of component recognition is lowered. Such a phenomenon can occur in the “center mode” described above. However, the occurrence of the above-mentioned phenomenon can be prevented by performing partial extinction control to turn off the unit light source 73 that can create an optical path for the illumination light to be reflected by the suction nozzle 42 and enter the slit 712. it can. Whether or not to perform such partial extinction can also be determined in step S5 in the flowchart of FIG.

FIG. 18 is a diagram illustrating a partial turn-off control example of the illumination unit 72 in the “center mode”. In FIG. 18, the scanning direction of the scanning unit 6 is indicated by an arrow. Here, an example of turning off the unit light source 73 arranged in the region E of the fifth block 75E (FIG. 7B), which is a block of the unit light source 73 along the scanning direction and upstream of the slit 712 is shown. The region E is a region that becomes an illumination portion near the outer periphery in the “center mode”, and is the unit light source 73 belonging to the second and

third arrangement portions

74B and 74C of the fifth block 75E. Instead, only the unit light source 73 of the second array portion 74B which is the outermost side in the “center mode” may be turned off.

FIG. 19 is a diagram for explaining the advantage of the partial turn-off control shown in FIG. The suction nozzle 42 of the head unit 4 may have a slope 421 above the suction port at the lower end thereof. Since the unit light source 73 is a light source having a Lambertian light distribution, illumination light is also applied to such a slope 421. The illumination light applied to the inclined surface portion 421 can be reflected toward the illumination unit substrate 71 side. Not only the inclined surface part 421 but also some part that reflects the illumination light toward the illumination unit substrate 71 may be provided.

In the illumination unit substrate 71A, a unit light source 73A that exists near the slit 712, and a unit light source 73B that exists far from the slit 712 (corresponding to the unit light sources 73 belonging to the second and

third arrangement portions

74B and 74C). Pay attention to the illumination lights LA and LB emitted by each. The illumination light LA of the unit light source 73A can be applied to the inclined surface portion 421 when the suction nozzle 42 reaches the imaging position immediately above the slit 712. However, since the directivity angle with respect to the suction nozzle 42 is small, the illumination light LA does not enter the slit 712 even if it is reflected by the inclined surface portion 421.

In contrast, the illumination light LB of the unit light source 73B has a larger directivity angle with respect to the suction nozzle 42 when the suction nozzle 42 reaches the imaging position immediately above the slit 712. For this reason, as shown in FIG. 19, the reflected light of the illumination light LB reflected by the inclined surface portion 421 is easily incident on the slit 712. In order to prevent such reflected light from entering the slit 712, the unit light source 73B may not be turned on. Accordingly, by causing the illumination control unit 82 to turn off the unit light sources 73 belonging to the second and

third arrangement units

74B and 74C of the block along the scanning direction, an image due to incidence of reflected light from the suction nozzle 42 Deterioration can be prevented.

[Second Embodiment of Lighting Unit]
FIG. 20 is a schematic plan view of an illumination unit 72A according to the second embodiment. In 1st Embodiment, the light quantity distribution A2 shown in FIG. 10 was produced by controlling the light quantity of the cyclic | annular arrangement | sequence part of the unit light source 73, and the example shown in FIG. In the second embodiment, an example is shown in which the light amount distribution A2 is created by the arrangement density of the unit light sources 73 instead of controlling the light amount.

In the illuminating unit 72A, a first array unit 74a, a second array unit 74b, and a third array unit 74c that are formed of an annular array of unit light sources 73 are concentrically arranged in this order from the radially outer side to the inner side. . Here, attention is focused on the second arrangement portion 74b (inner arrangement portion) and the first arrangement portion 74a (outer arrangement portion). In the second arrangement portion 74b, four unit light sources 73 are arranged in an annular shape at an equal pitch of the arrangement pitch g1 (first arrangement pitch). On the other hand, in the first arrangement portion 74a, twelve unit light sources 73 are arranged in an annular shape at the arrangement pitch g2 (second arrangement pitch), and the arrangement pitch is denser than the arrangement pitch g1 of the second arrangement portion 74b.

By setting the arrangement pitch of the unit light sources 73 as described above, even when all the unit light sources 73 of the illumination unit 72A emit light with the same light amount, the unit light source 73 group of the third arrangement unit 74c arranged on the radially outer side. And the amount of light reaching the electronic component 32, and the amount of light reaching the electronic component 32 when the illumination light emitted from the unit light source 73 group of the second arrangement portion 74b arranged on the radially inner side. Can be made substantially the same. That is, a light amount distribution approximate to the light amount distribution A2 shown in FIG. 10 can be created.

FIG. 21A is a plan view showing a specific example of the illumination unit 64A according to the second embodiment, and FIG. 21B is an enlarged view of the illumination unit 72A of the illumination unit 64A. The illumination unit 64A includes an illumination unit substrate 71 and an illumination unit 72A (illumination device). The illumination unit substrate 71 is the same as described above based on FIG. 7A. The illuminating unit 72A is formed of an integrated unit light source 73 in which a plurality of unit light sources 73 are arranged concentrically. As schematically shown in FIG. 20, the unit light sources 73 are arranged densely on the radially outer side and roughly on the radially inner side.

In FIG. 21B, reference numerals 74A to 74J indicate arrangement positions corresponding to the positions of the first to tenth arrangement sections 74A to 74J shown in FIG. 7B. As for the first and

second arrangement portions

74A and 74B on the outer side in the radial direction, the unit light sources 73 are arranged in an annular shape at a dense arrangement pitch as in FIG. 7B. On the other hand, the arrangement pitch of the unit light sources 73 is made coarser in the third to sixth arrangement parts 74C to 75F on the radially inner side than these in comparison with the first and

second arrangement parts

74A and 74B. Further, the radially inner seventh to tenth array portions 74G to 75J include an array portion in which the unit light sources 73 are not disposed at all. That is, the unit light source 73 is arranged in the seventh and ninth arrangement parts 74G and 74I, but the unit light source 73 is not arranged in the eighth and

tenth arrangement parts

74H and 74J.

[Function and effect]
According to the surface mounter 1 (imaging device) according to the first and second embodiments described above, the plurality of unit light sources 73 are planes orthogonal to the perpendicular V of the electronic component 32 sucked by the suction nozzle 42. Since the illumination unit substrate 71 is disposed on the upper surface 71U, the illumination unit 64 can be thinned. The illumination unit 72 of the illumination unit 64 includes an inner array unit and an outer array unit arranged in a concentric manner as an array group of the plurality of unit light sources 73 (in the example of FIG. 9, first to third array units 74a). At least 74c). For this reason, illumination light L1, L2, L3 can be irradiated from the perimeter of the adsorbed electronic component 32. Furthermore, the amount of light reaching the electronic component 32 of the illumination light L2 from the inner array portion (second array portion 74b) and the amount of light reaching the electronic component 32 of the illumination light L1 from the outer array portion (first array portion 74a) are: Since they can be made substantially the same, it is possible to irradiate the electronic component 32 with uniform illumination light without unevenness. Therefore, accurate component shape recognition can be performed from the image of the electronic component 32 captured by the component recognition camera 65.

According to the first embodiment, by adjusting the light amount of the unit light source 73 arranged in the first to tenth array portions 74A to 74J, the amount of light reaching the electronic component 32 of the illumination light emitted from each array portion 74A to 74J can be easily achieved. Can be adjusted. In addition, according to the second embodiment, the illumination light emitted from each of the array units 74A to 74J depends on the array density of the unit light sources 73 disposed in the first to tenth array units 74A to 74J, that is, the number of unit light sources 73 disposed. The amount of light reaching the electronic component 32 can be easily adjusted.

The specific embodiments described above mainly include inventions having the following configurations.

According to this imaging apparatus, since the plurality of unit light sources are arranged on a plane perpendicular to the perpendicular of the component (suction component) sucked by the suction nozzle, the lighting device can be made thin. In addition, the lighting device includes at least an inner array portion and an outer array portion arranged concentrically as an array group of a plurality of unit light sources. For this reason, illumination light can be irradiated from the entire periphery of the suction component. Furthermore, since the amount of illumination light reaching the suction component of the inner array portion and the amount of illumination light reaching the suction component of the outer array portion are substantially the same, uniform illumination light with no unevenness in the suction component Can be irradiated. Therefore, accurate component shape recognition can be performed from the image of the suction component imaged by the component imaging device.

Note that the amount of light reaching the inner arrangement portion irradiating the suction component and the amount of light reaching the outer arrangement portion irradiating the suction component are defined as “substantially the same”. This is because it is practically difficult. Moreover, even if there is a slight difference in the amount of light reaching the both, it is possible to make the suction component illuminated substantially uniformly. For example, when the amount of light reached by the other array part differs within about ± 20% of the amount of light reached by one array part, preferably when it differs within the range of about ± 10%. Even if it exists, since the subject of this invention can be achieved, this is a category of "substantially the same."

The imaging apparatus may further include a light amount control unit that controls light amounts of the plurality of unit light sources, and the light amount control unit causes each unit light source of the inner array unit to emit light with a predetermined first light amount, and the outer array. It is preferable that each unit light source of the unit emits light with a second light amount larger than the first light amount.

According to this imaging apparatus, the amount of light reaching each array portion can be easily adjusted by adjusting the light amount of the unit light sources included in each of the inner array portion and the outer array portion. Further, depending on the first light amount and the second light amount, it is not necessary to consider the directivity of each unit light source, so that an optical component such as a lens for providing the illumination light with a specific directivity is unnecessary. can do.

In this case, the unit light source has a Lambertian light distribution, the directivity angle of the unit light source of the inner array portion with respect to the component is θ1, and the directivity angle of the unit light source of the outer array portion with respect to the component is θ2. In this case, it is preferable that the light amount control unit sets the first light amount based on 1 / cos ⁴ θ1, and sets the second light amount based on 1 / cos ⁴ θ2.

When the unit light source is a light source having a Lambertian light distribution, if the inclination angle (directivity angle) with respect to the optical axis of the light source is θ, the light amount decreases in proportion to cos ⁴ θ (cosine fourth power rule). Accordingly, by setting based on the reciprocal of cos ⁴ θ1 and cos ⁴ θ2 in accordance with the directivity angles θ1 and θ2 of the unit light sources in the inner and outer array units, the amount of light reaching the first amount of illumination light and the light amount The reaching light amount of the second light amount of illumination light can be made substantially the same.

In the imaging apparatus, the unit light sources are arranged in a ring shape at a predetermined first arrangement density in the inner arrangement portion, and the unit light sources are denser than the first arrangement density in the outer arrangement portion. It is desirable that they are arranged in a ring shape with a density.

According to this imaging apparatus, the amount of light reaching each array section can be easily adjusted by the array density of unit light sources disposed in the inner array section and the outer array section, that is, the number of unit light sources disposed. Also, depending on the number of unit light sources arranged, there is no need to consider the directivity of each unit light source, so that it is possible to eliminate the need for an optical component such as a lens for providing illumination light with a specific directivity. .

In the imaging apparatus, the base includes an opening around the arrangement center, and an imaging optical axis of the component passes through the opening to the component imaging apparatus, and the inner arrangement section and the outer arrangement section. Is preferably arranged around the opening.

According to this imaging device, the opening and the component can be aligned, and the reflected light of the illumination light irradiated to the component from the inner and outer arrangement portions can be guided to the component imaging device through the opening. Therefore, the optical path for imaging can be set compactly.

In this case, a lighting control unit that controls lighting and extinguishing of the plurality of unit light sources is further provided, and the component imaging device includes a line sensor, and moves below the component sucked by the suction nozzle in a predetermined scanning direction. The lighting control unit is configured to acquire an image of the component, and the lighting control unit reflects the illumination light to the suction nozzle among the plurality of unit light sources during the movement of the component imaging device. It is desirable to perform control to turn off a unit light source that can form an incident optical path.

According to this imaging device, it is possible to prevent the illumination light irradiated to the suction nozzle from entering the component imaging device through the opening, that is, the reflected light other than the reflected light from the component can be prevented from entering the component imaging device. Therefore, when the image of the component is acquired by scanning of the component imaging device including the line sensor, a clear image of the component can be acquired.

In the above imaging apparatus, it is desirable that the unit light source is an LED (light emitting diode). In the case of an LED, the adjustment of the amount of light can be easily performed by controlling the drive current. It is also easy to use a circuit board as a base and arrange the LEDs on the circuit board at a desired pitch.

A surface mounter according to another aspect of the present invention includes a head unit including a suction nozzle that mounts a component on a substrate, and the imaging device described above. According to this surface mounter, it is possible to accurately recognize the component based on the image of the component acquired by the imaging apparatus and to perform component mounting with high accuracy.

[Explanation of symbols]
1 Surface mounter 32 Electronic component 32 (component)
4 Head unit 42 Suction nozzle 6 Scan unit (imaging device)
60 Moving frame 64 Lighting unit (lighting device)
65 Component recognition camera (component imaging device)
651 Line sensor 71 Lighting unit substrate (base)
71U Top surface (plane)
712 Slit (opening)
72 Illumination unit (illumination device)
73 Unit light sources 74A to 74J 1st to 10th array parts (inner array part, outer array part)
74a to 74c First to third arrangement parts (inner arrangement part, outer arrangement part)
8 control unit 81 camera control unit 82 illumination control unit (light quantity control unit / lighting control unit)
L, L1, L2, L3 Illumination light OP1 Light quantity (second light quantity)
OP2 Light intensity (first light intensity)
P substrate Q imaging optical axis V perpendicular X scan direction point a (point where the perpendicular intersects the plane)
g1, g2 arrangement pitch (first and second arrangement pitch)

Claims

An imaging device for a component sucked by a suction nozzle for mounting the component on a substrate,
An illumination device for illuminating the component with illumination light from below;
A component imaging device that images the component irradiated with the illumination light,
The lighting device includes a base having a plane orthogonal to a perpendicular passing through a component sucked by the suction nozzle, and a plurality of unit light sources that emit the illumination light and are arranged on the plane.
The illumination device includes an inner array portion in which at least a part of the plurality of unit light sources is annularly arranged around a point where the perpendicular intersects the plane when irradiated with the illumination light, and an inner array portion of the inner array portion. An outer array portion in which other portions of the plurality of unit light sources are arranged in a ring shape on the radially outer side includes an array structure arranged concentrically on the plane;
The amount of light reaching the component with illumination light emitted from the unit light source group of the inner array portion and the amount of light reaching the component with illumination light emitted from the unit light source group of the outer array portion An imaging device that is substantially identical.
The imaging device according to claim 1,
A light amount control unit for controlling the light amount of the plurality of unit light sources;
The imaging apparatus, wherein the light amount control unit causes each unit light source of the inner array unit to emit light with a predetermined first light amount, and causes each unit light source of the outer array unit to emit light with a second light amount greater than the first light amount.
The imaging device according to claim 2,
The unit light source has a Lambertian light distribution,
When the directivity angle of the unit light source of the inner array portion with respect to the component is θ1, and the directivity angle of the unit light source of the outer array portion with respect to the component is θ2,
The imaging apparatus, wherein the light amount control unit sets the first light amount based on 1 / cos 4 θ1, and sets the second light amount based on 1 / cos 4 θ2.
The imaging device according to claim 1,
In the inner arrangement portion, the unit light sources are arranged annularly at a predetermined first arrangement pitch,
The imaging device, wherein the unit light sources in the outer array section are annularly arranged at a second array pitch that is denser than the first array pitch.
The imaging apparatus according to any one of claims 1 to 4,
The base includes an opening around the arrangement center, and the imaging optical axis of the component passes through the opening to the component imaging device,
The imaging device, wherein the inner array portion and the outer array portion are arranged around the opening.
The imaging apparatus according to claim 5,
A lighting control unit for controlling lighting and extinguishing of the plurality of unit light sources;
The component imaging device includes a line sensor, and acquires an image of the component by moving in a predetermined scanning direction below the component sucked by the suction nozzle,
The lighting control unit performs control to turn off a unit light source that can create an optical path in which illumination light is reflected by the suction nozzle and enters the opening among the plurality of unit light sources during the movement of the component imaging device. , Imaging device.
The imaging apparatus according to any one of claims 1 to 6,
An imaging apparatus in which the unit light source is an LED.
A head unit having a suction nozzle for mounting components on a substrate;
An imaging device according to any one of claims 1 to 7,
A surface mounting machine.