JP4922890B2 - Electronic component mounting method - Google Patents

Description

  The present invention relates to an electronic component mounting apparatus including a device that detects an electronic component that needs to be removed among electronic components that have fallen into the field of view of a component recognition camera when mounting the electronic component on a substrate.

  The electronic component is mounted on the printed circuit board by adsorbing the electronic component supplied by the component supply device by a component adsorbing device (adsorption nozzle) that adsorbs the electronic component and mounting the adsorbed electronic component on the printed circuit board printed with solder. Is done. Then, after this suction and before mounting, the correct electronic component is inspected in the correct posture (the quality of the electronic component) is inspected based on the component recognition camera, and the electronic component that has passed this inspection is actually mounted on the printed circuit board. Installing. However, because the component suction device moves at high speed from the component supply device and suddenly decelerates or stops due to the imaging conditions on the component recognition camera, the sucked electronic component falls off the suction nozzle due to inertial force. However, it may fall on the field of view of the component recognition camera. Such a fallen electronic component may cover a part of the field of view of the component recognition camera, and the normal electronic component may be determined to be abnormal.

Therefore, in the technology described in Patent Document 1, luminance information on a plurality of straight lines in an image captured before the mounted electronic component enters the component field of the image input unit, and the electronic component stored in advance are stored. The brightness information on a predetermined plurality of straight lines in an image in a normal state that does not exist is compared, and foreign matter in the component visual field is detected based on the difference between the brightness information.
Japanese Patent No. 2801337

  However, in the technique of Patent Document 1, since a contrast difference is small in an image to be captured, a clear image of a foreign object cannot be captured, and the aperture is opened using an optically bright lens because the captured image is dark. In order to capture an image, it is difficult to capture a clear image of a foreign object without maintaining a depth of field that can cover the deviation between the set focus position of the camera and the dust position. Therefore, there has been a problem that it is difficult to accurately determine the time for removing foreign substances that cause an abnormality in the inspection of electronic components. In general, even if there is an electronic component that falls within the field of view of the component recognition camera, if it is in a range that does not affect the judgment of the quality of the sucked electronic component, it is better not to perform the removal work each time From the viewpoint of production efficiency and work efficiency, it is desirable.

  In view of the above-described problems, the present invention includes an inspection device that can easily determine whether or not a foreign object that has fallen into the field of view of a component recognition camera hinders the inspection for determining the quality of a mounted electronic component. An electronic component mounting apparatus is provided.

In order to solve the above-described problem, the structural feature of the invention according to claim 1 is supported so as to be movable in two directions, ie, a direction in which the substrate is transported by the substrate transport device and a direction perpendicular to the transport direction. A movable table, a component transfer device that is attached to the movable table and is mounted on the substrate that is positioned and supported on the substrate transport device by sucking the components supplied by the component supply device, and the movable table. A board recognition camera provided for recognizing the position of the board, and a base mounted between the board transfer device and the component supply device, and picks up an electronic component adsorbed by the component transfer device in the electronic component mounting apparatus having a component recognizing camera, a light source for illuminating the electronic component from the component recognition camera, and a portion of the component transfer apparatus, covering the field of view of said component recognizing camera back Scree The member is provided, with the electronic component does not exist which fall into the field of view of the component recognition camera, the background of the back screen member, and the reference image capturing step of capturing an image by the component recognizing camera, the reference image An imaging component imaging step in which the electronic component picked up by the component transfer device after the imaging step is imaged by the component recognition camera, and an image by the component recognition camera with the back screen member as a background after the adsorption component imaging step. And a removal part detection determination step of determining whether or not it is necessary to remove the dropped electronic component by comparing the confirmation image with the reference image .

Structural feature of the invention according to Claim 2 resides in that in Claim 1, after the removal part detection judging step, be provided with a falling part removing step of removing an electronic component that has fallen to the field portion of said component recognizing camera It is.

According to the first aspect of the present invention, in the reference image capturing step, an image in a state where the electronic component dropped in the confirmation image capturing step exists with the same back screen member provided in the part transfer device side as a background . By comparing the image captured in the absence of electronic components that have been dropped in advance with the same brightness and darkness on the lens of the component recognition camera or on the screen, the necessity of removing the dropped electronic components can be accurately determined. Since the determination can be made, it is possible to maintain a state in which the component recognition camera can recognize the quality of the electronic component sucked by the component transfer device with high accuracy.

According to the second aspect of the present invention, when it is determined that it is necessary to remove the dropped electronic component in the removal part detection determination process, the removal work can be immediately performed by the falling part removal process. Can recognize the quality of the electronic component adsorbed by the component transfer device with high accuracy.

  An embodiment of an electronic component mounting 1 according to the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram showing the entire electronic component mounting apparatus, and FIG. 2 is a diagram showing the positional relationship between a component recognition camera 4 and a board recognition camera 6.

  As shown in FIG. 1, the electronic component mounting apparatus 1 is provided with a substrate transfer device 3 that transfers the substrate S in the transfer direction (X direction). On the upper side of the substrate transfer device 3, a slide 10 that is elongated in the Y direction orthogonal to the X direction is fixed to the lower surface of a table (not shown) that is guided and supported by a fixed rail (not shown) that extends in the X direction. The movement of the slide 10 in the X direction is controlled by an unillustrated X direction servo motor via a ball screw. On one side of the slide 10, a moving table 20 to which the board recognition camera 6 and the component transfer device 18 are attached is guided and supported so as to be movable in the Y direction. It is controlled by a motor. The slide 10, the moving table 20, the substrate recognition camera 6 and the component transfer device 18 attached thereto are provided on the upper side of the substrate transfer device 3.

  As shown in FIG. 3, the substrate recognition camera 6 includes an LED light source 24 that is irradiated downward, a refraction mirror 26 that refracts the vertical optical axis from below into a horizontal optical axis, and refraction. And a main body 28 for converting an image captured along the optical axis entering the horizontal direction by the mirror 26 into a digital signal. The main body 28 is formed in a square box shape, and a white rectangular plate 30 (50 mm × 50 mm) as a back screen member is attached to the lower surface. The substrate recognition camera 6 is connected to the component transfer device 18 and constitutes a part on the component transfer device side.

  As shown in FIG. 2, the component transfer device 18 is supported by a support base 38 that is detachably attached to the movable table 20, and is supported by the support base 38 so as to be movable up and down in the Z direction perpendicular to the X direction and the Y direction. A component mounting head 32 whose elevation is controlled by an unillustrated X-direction servomotor via a ball screw, and a cylindrical suction that protrudes downward from the component mounting head 32 and holds the component P at the lower end. And a nozzle (component sampling unit) 36. A plurality of cylindrical nozzle holders 34 are attached to the component mounting head 32 so as to be rotatable about an axis. A suction nozzle 36 that can reciprocate in the vertical direction is attached to the nozzle holder 34, and each suction nozzle 36 is biased upward by a compression spring (not shown). The nozzle holder 34 is intermittently rotated by a motor (not shown) so that the suction nozzle 36 stops at a predetermined position. The substrate recognition camera 6 is fixed to the movable table 20 and is not replaced except in the case of a failure, and its optical axis is parallel to the Z direction.

  On one end side of the electronic component mounting apparatus 1, an unillustrated component supply apparatus including a plurality of feeders installed side by side is provided. A component recognition camera (CCD camera) 4 having an optical axis O1 parallel to the Z direction is provided on a base 8 between the substrate transfer device 3 and the component supply device. As shown in FIGS. 2 and 3, the component recognition camera 4 is mounted on a base 8 via a support base 44, and has a bowl-shaped upper wall body with a bottom open on the upper side (above). Support member) 46 and a lower wall body 48 constituted by four perpendicular surfaces are provided. A transparent upper glass 50 is provided on the open upper surface of the upper wall 46, and a rectangular hole 52 is provided through the center of the upper glass 50. Since this rectangular hole 52 is close to the focal position of the component recognition camera 4 for recognizing the electronic component P when dust or the like accumulates at the central position of the upper glass 50, the quality of the electronic component P is immediately determined (adsorption posture / component itself). Since this affects the determination, it is provided to prevent this. When the quality of the electronic component P adsorbed by the adsorption nozzle by the component recognition camera 4 is judged, the position of the dropped electronic component and the focal position of the electronic component P adsorbed by the nozzle have a larger difference. This is considered preferable because the component is out of the range of the depth of field of the in-focus camera. On the other hand, in the removal determination of the dropped electronic component P, it is considered desirable to clearly show the dropped electronic component P in order to determine whether or not the dropped electronic component P needs to be removed.

  The upper wall body 46 and the lower wall body 48 are partitioned by a transparent cover glass 54 kept substantially horizontal, and a large number of LEDs are laid on the entire surface of the upper wall body 46 and one surface of the lower wall body 48. ing. The LED of the upper wall 46 is used as a side light source 56, and the LED of the lower wall 48 is used as an incident light source 58 so that the component P recognized by the component recognition camera 4 and the lower end of the suction nozzle 36 are illuminated from below. It has become. A half mirror 60 is disposed between the cover glass 54 and the component recognition camera 4 so as to be inclined from the horizontal. The half mirror 60 reflects light from the incident light source 58 on the lower wall 35 upward. It is configured. An image captured by the component recognition camera 4 is captured and stored in an image recognition device 62 as a removal part detection determination unit.

  The electronic component mounting apparatus 1 detects the position of a board mark (not shown) provided on the board S which is carried in and held by the board carrying apparatus by the board recognition camera 6, and based on the position of the board mark. The electronic component P held by suction at the tip of the suction nozzle 36 of the component transfer device 18 is moved from the component supply device (not shown) by moving the slide 10 and the movable table 20 in the X direction and the Y direction. It is mounted at the commanded coordinate position on the substrate S. Further, while the component P sucked and held at the tip of the suction nozzle 36 is moved from the component supply device 42 to the commanded coordinate position on the substrate S, the suction nozzle 36 is temporarily stopped on the component recognition camera 4 and sucked. The component recognition camera 4 detects the misalignment of the component P with respect to the center line O3 of the suction nozzle 36 and the misalignment of the center line. Then, after correcting the suction nozzle 36 based on the detection result of the angular deviation, the movement amount in the X direction and the Y direction of the slide 10 and the movable table 20 is corrected based on the detection result of the misalignment, and the component P is replaced with the substrate S. It is mounted accurately at the commanded coordinate position with the upper substrate mark as a reference.

  Next, the operation of the falling part detection apparatus configured as described above will be described below. First, as a preprocessing, a field-of-view image of the component recognition camera 4 in which the component is not captured in a normal state is captured and stored in the image recognition device 62. At the time of imaging, for example, the side light source 56 and the epi-illumination light source 58 are all turned on and imaged at a shutter speed of 40 m / s. Only the white plate 30 attached to the lower surface of the abdomen of the board recognition camera 6 is captured in the visual field image.

  Next, the component transfer device 18 is moved to the component supply device (not shown), and the electronic component P is sucked by the suction nozzle 36 and moved to the inspection position between the component supply device and the mounting position of the substrate S. Let Then, the suction posture of the electronic component P sucked by the component recognition camera 4 and the quality of the electronic component itself are determined. If necessary, the electronic component P is corrected and mounted on the board S. Then repeat this. Several electronic components P fall on the cover glass 54 during the repetition.

  Next, the board recognition camera 6 is moved, and the white plate 30 attached to the board recognition camera 6 is imaged in a state of being put in the field of view of the component recognition camera. In this case as well, the side light source 56 and the epi-illumination light source 58 are all turned on and images are taken at a shutter speed of 40 m / s. Then, for example, an image as shown in FIG. 5 is obtained, and the image is recognized by the image recognition device 62 and stored. Next, the image recognition device 62 divides this image into a matrix as shown in FIG. 8, and the gray value average of each pixel in the divided cell is expressed as the gray value of the cell. The gray value is expressed by, for example, setting black as 0 and pure white as 255, and numerical values between them. In this case, a gray value is obtained as shown in FIG. In addition, as shown in FIG. 7, the pre-captured image is also divided into a matrix, and each of the divided cells is represented by a gray value shown in FIG. 10. Then, for each corresponding cell, the difference value between the gray value in FIG. 9 and the gray value in FIG. 10 is calculated (see FIG. 11). In the preparation stage, a threshold value is set in advance for the difference value and compared with the obtained difference value of the gray value. When the obtained difference value exceeds the threshold value, it is determined to remove the electronic component P on the cover glass 54. In the present embodiment, for example, the absolute value of the difference value of the gray value of one cell is set not to be 100 or more. In the present embodiment, the largest difference is 194-251 = −57 in D of 4 and the absolute value of the difference value is 57, which is not 100 or more. Therefore, it is determined that the electronic component is not removed. . As described above, by removing the falling objects in the range that is determined not to affect the quality determination of the electronic component P sucked by the component recognition camera 4 by the threshold value, the work efficiency and the production efficiency are improved by not performing the removal work. Can be made.

  Next, when the image shown in FIG. 6 is obtained as another image, it is similarly divided into a matrix as shown in FIG. 13, and each of the divided cells is shown in FIG. , Expressed in gray values. In addition, as shown in FIG. 12, the pre-captured image is also divided into a matrix, and each of the divided cells is represented by a gray value shown in FIG. Then, for each corresponding cell, a difference value between the gray value in FIG. 14 and the gray value in FIG. 15 is obtained (see FIG. 16). In this case, a difference value of −153 is obtained with G of 5 and −115 with G of 6 and the absolute value of these difference values exceeds the threshold value of 100. It is determined to do.

  This threshold value is set in consideration of the size, shape, presence / absence of leads, etc. of the electronic component to be mounted. Further, it may be obtained from an average value of the entire difference value, and the roughness of the matrix grid can be appropriately changed according to the electronic component to be mounted. Moreover, it is not necessarily limited to the numerical value by the gray value etc., For example, visual judgment by an operator may be sufficient.

  According to the electronic component mounting apparatus 1 configured as described above, since the dropped electronic component P is imaged against the white plate 30 as a background, the contrast of the image of the dropped electronic component P in the captured image becomes clear. Further, since the white plate 30 is used as a background, the image screen is bright and the depth of field can be increased, and the dropped electronic component P can be clearly seen even if the focal position and the falling position of the dropped electronic component are separated. Images can be captured. In addition, by comparing an image in a state where the dropped electronic component P exists with an image captured in a state where there is no electronic component dropped in advance, the brightness on the lens of the component recognition camera 4 or on the screen is made uniform. By doing so, it is possible to accurately determine whether or not it is necessary to remove the dropped electronic component P. Accordingly, the quality of the electronic component P can be always determined with high accuracy by the component recognition camera 4.

  Further, since the plate 30 is provided on the lower surface of the abdomen of the board recognition camera 6, it is easy to move the abdomen of the board recognition camera 6 to the field of view of the component recognition camera 4 without requiring a special device. A white background can be realized.

  Next, a second embodiment of the electronic component mounting apparatus according to the present invention will be described below with reference to the drawings. As shown in FIG. 17, the component mounting head 32 in this electronic component mounting apparatus is the first embodiment in that a suction nozzle 70 for cleaning as a fallen part removing means is provided in one of the suction nozzles 36. It differs from the form. Since other configurations are the same, the same reference numerals are given and description thereof is omitted.

  In this embodiment, a suction nozzle 70 whose lower end reaches the upper surface of the cover glass 54 is provided in the nozzle holder 34 provided in the component mounting head 32 for the dropped electronic component P, instead of the suction nozzle 36. When it is determined that the dropped electronic component P is to be removed, the electronic component P on the cover glass 54 is removed by suction by the suction nozzle 70. As described above, since the dropped electronic component P can be removed using the vacuum device communicating with the existing nozzle holder 34 and the suction nozzle, the electronic component P dropped easily and reliably without causing any new equipment cost. Can be removed. When it is determined that it is necessary to remove the dropped electronic component P, the removal operation is immediately performed, and the component recognition camera 4 is attracted to the component transfer device 18 (suction nozzle 36). It is possible to recognize the quality of P with high accuracy.

  Next, a third embodiment of the electronic component mounting apparatus according to the present invention will be described below with reference to the drawings. As shown in FIG. 18, the upper glass 80 is not provided with a rectangular hole above the component recognition camera 4 in this electronic component mounting apparatus, and dropped on the upper glass 80 as falling part removing means. The second embodiment is different from the first embodiment in that a compressed air discharge port 82 for removing the electronic component P is provided. Since other configurations are the same, the same reference numerals are given and description thereof is omitted. An air pump (not shown) communicates with the compressed air discharge port 82 via a hose 84, and air compressed by the air pump is discharged from the compressed air discharge port 82 by opening and closing a solenoid valve (not shown) provided in the middle of the hose 84. It is supposed to be. By ejecting the compressed air vigorously, the electronic component P on the upper glass 80 can be blown off and removed.

  In the above embodiment, the suction nozzle and the discharge port are provided as means for removing the dropped electronic component. However, the present invention is not limited to these, and for example, it may be removed by adsorption with an electromagnetic magnet. It may be removed by bonding with a member.

  In addition, the part transfer device side portion is the lower surface of the abdomen of the substrate recognition camera, but is not limited to this, and moves with the component transfer device, and a back screen member is provided to face the component recognition camera. Any site can be selected as long as it is possible.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic diagram which shows the whole electronic component mounting apparatus of this invention. The figure which shows the positional relationship of the camera for component recognition and the camera for board | substrate recognition. The figure which shows the positional relationship of a back screen and the camera for component recognition. The figure which shows the camera for component recognition, and the arrangement structure of a light source. The figure which shows the image of the camera for component recognition which the electronic component fell on the cover glass. The figure which shows the image of the camera for component recognition which the electronic component fell on the cover glass. The figure which shows the image of the camera for component recognition previously imaged and memorize | stored with a matrix screen. The figure which shows the image of the camera for component recognition which the electronic component fell on the cover glass with a matrix screen. The figure which shows the matrix screen imaged and memorize | stored beforehand with a gray value. The figure which shows the matrix screen by which the electronic component fell on the cover glass with a gray value. The figure which shows the difference value of a gray value. The figure which shows the image of the camera for component recognition previously imaged and memorize | stored with a matrix screen. The figure which shows the image of the camera for component recognition which the electronic component fell on the cover glass. The figure which shows the image of the camera for component recognition previously imaged and memorize | stored with a matrix screen. The figure which shows the image of the camera for component recognition which the electronic component fell on the cover glass with a matrix screen. The figure which shows the difference value of a gray value. The figure which shows 2nd Embodiment. The figure which shows 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electronic component mounting apparatus, 4 ... Component recognition camera, 6 ... Board recognition camera, 18 ... Component transfer apparatus, 20 ... Moving stand, 30 ... Back screen, 54 ... Cover glass, 56 ... Light source (side light source) , 58... Light source (epi-illumination light source), 62... Removal part detection / determination means (image recognition device), 70... Fallen part removal means (suction nozzle), 82 .. fallen parts removal means (compressed air discharge port), S. , P: Electronic component.

Claims (2)

A moving table supported so as to be movable in two directions, that is, a direction in which a substrate is transferred by the substrate transfer device and a direction orthogonal to the transfer direction, and a component attached to the moving table and sucked by a component supply device Then, a component transfer device mounted on the substrate that is positioned and supported on the substrate transfer device, a substrate recognition camera that is provided on the moving table and recognizes the position of the substrate, and the substrate transfer device; A component recognition camera that images the electronic component that is fixed to the base between the component supply device and is sucked by the component transfer device; and a light source that illuminates the electronic component from the component recognition camera side. In the electronic component mounting apparatus provided,
To the site of the component transfer apparatus is provided with a back screen member covering the field of view of said component recognizing camera,
In a state where electronic components fall into the field of view of the component recognition camera is not present, the background of the back screen member, and the reference image capturing step of capturing an image by the component recognizing camera,
A suction component imaging step of imaging the electronic component sucked by the component transfer device after the reference image imaging step by the component recognition camera;
After the suction component imaging step, with the back screen member as a background, a confirmation image imaging step of capturing an image with the component recognition camera;
An electronic component mounting method comprising: a removal part detection determination step of determining whether or not it is necessary to remove a dropped electronic component by comparing the confirmation image with the reference image. According to claim 1, after the removal part detection judging step, the electronic component mounting method characterized in that it comprises a drop part removing step of removing an electronic component that has fallen to the field portion of said component recognizing camera.

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