JP4091950B2 - Component mounting position correction method and surface mounter - Google Patents

Description

  The present invention relates to a mounting position correction method for a surface mounter configured to mount a component such as an IC on a printed board, and a surface mounter capable of performing the correction method.

  Conventionally, an electronic component such as an IC is sucked from a component supply unit by a movable head unit having a suction head for picking up the component, and the component is transferred and mounted on a printed circuit board positioned at a predetermined work position. Such surface mounters are generally known.

  In this type of mounting machine, it is necessary to mount on the printed circuit board in consideration of the component suction displacement with respect to the suction head. That is, it is necessary to correct the movement target position at the time of mounting the head unit according to the component suction state.

  As this method, for example, a mark is provided in the vicinity of the suction head of the head unit, the positional relationship between the mark and the suction head is examined in advance and stored as known information, and a camera comprising a CCD area sensor is provided on the base, After picking up the part, the mark and the picked-up part are imaged by a camera, and the amount of shift of the part with respect to the pick-up head is obtained based on the positional relationship between the mark and the picked-up part on the image and the known positional relation. It is conceivable to correct the mounting position.

  By the way, in this type of mounting machine, it is known that a movement error occurs in the head unit due to a driving error, a thermal expansion of a mechanism portion, and the like, which affects the mounting accuracy. Sometimes, if such a movement error of the head unit can be examined, it is possible to more accurately correct the mounting position of the component, which is convenient.

  Further, in the above conventional method, since it is necessary to image the mark and the suction component with a camera comprising a CCD area sensor, for example, in a mounting machine having a plurality of suction heads in the head unit, it is necessary to provide a mark for each suction head However, in recent years, the head unit tends to be miniaturized in order to increase the mounting speed, and there is a problem that it is difficult to provide a mark for each suction head in terms of space. Therefore, it is also necessary to be able to detect the component adsorption deviation accurately while responding to the demand for downsizing of the head unit.

  The present invention has been made to solve the above-described problem, and enables components to be mounted on a board with higher accuracy, preferably rationally correcting the component mounting position by the head unit. For the purpose.

In order to solve the above-described problem, a method according to claim 1 of the present invention is configured to suck an electronic component from a component supply unit by a movable head unit having a plurality of suction heads for mounting the component, A mounting position correction method for mounting on a substrate positioned at a working position of the above, using a camera having a linear sensor provided on a base , and moving the head unit onto the camera The suction component by the suction head and the pair of marks provided on the head unit are continuously captured as one image, and the positional relationship between the mark and the suction component on the image and known information are obtained from the image. The amount of component suction deviation is determined based on the positional relationship between the mark and the suction head, and the head unit is determined based on the interval between the marks on the image and the reference value of the interval. Seek movement error of, it is obtained so as to correct the mounting position of the component by the head unit on the basis of the adsorption amount of deviation and the movement error.

According to this method, it becomes possible to detect a movement error of the head unit due to a drive error or a thermal expansion of a mechanism portion based on the imaging of the mark provided on the head unit, thereby improving the reliability of the mounting position correction. improves. Further, the drive accuracy of the components can be improved by further controlling the driving of the head unit based on the amount of suction deviation of the components. Furthermore, since the suction component and the mark are continuously captured as one image while moving the head unit with respect to the linear sensor, the amount of suction displacement of each component and the movement of the head unit with fewer marks than the number of suction heads. The mounting position can be corrected by checking the error.

On the other hand, a surface mounter according to claim 2 of the present invention sucks an electronic component from a component supply unit by a movable head unit having a plurality of suction heads for mounting the component, and places the component at a predetermined work position. A surface mounter for mounting on a substrate positioned at a position having a pair of marks provided on the head unit and a linear sensor disposed on a base and capable of picking up suction parts by the suction head and the marks. A predetermined mounting operation is performed with the camera, and the head unit is moved over the camera to drive the head unit so that the suction component by the suction head and the pair of marks are continuously captured as one image. Based on the control means for controlling and the captured image, the positional relationship between the mark and the suction component on the image, and the mark and suction head which are known information. And calculating means for calculating the movement error of the head unit based on the interval on the image of both marks and the reference value of the interval. The control means is configured to correct the mounting position of the component by the head unit based on the suction displacement amount and the movement error obtained by the calculation means.

According to this surface mounter, a pair of marks is picked up by the head unit moving on the camera, and the head unit movement error is obtained based on the image. During the mounting operation, the head unit is based on the movement error. The mounting position of the component is corrected by controlling the driving of. Further, the mounting position of the component is corrected by further controlling the driving of the head unit based on the amount of suction deviation.

According to the mounting position correction method component according to claim 1 of the present invention, it may be provided with a pair of marks on the head unit, the head unit by examining the distance between the marks these are captured on the image by the camera Since the movement error is obtained and the mounting position of the component by the head unit is corrected based on this error, the movement error of the head unit due to the drive error or the thermal expansion of the mechanism portion is eliminated, and the mounting accuracy is improved. it can. In particular, the mounting accuracy can be improved because the mounting position of the component is corrected by taking the suction error of the component into account with the movement error, and the suction component and the mark are made as one image while moving the head unit with respect to the linear sensor. By imaging continuously, it is possible to check the amount of suction displacement of each component and the movement error of the head unit with fewer marks than the number of suction heads, and correct the mounting position. It is possible to rationally correct the component mounting position.

According to the surface mounter according to the second aspect , the method according to the first aspect can be satisfactorily performed during a series of mounting operations, and thus the mounting accuracy can be increased.

  Embodiments of the present invention will be described with reference to the drawings.

  1 and 2 schematically show an example of a surface mounter (hereinafter abbreviated as a mounter) according to the present invention. In this figure, a conveyor 2 constituting a conveyance line is arranged on a base 1 so that a printed circuit board 3 is conveyed on the conveyor 2 and stopped at a predetermined working position. It has become.

  A component supply unit 4 is disposed on the side of the conveyor 2. The component supply unit 4 includes, for example, multiple rows of tape feeders 4a, and each tape feeder 4a stores and holds small pieces of electronic components such as ICs, transistors, and capacitors at predetermined intervals. Are arranged so as to be led out from the reel, and a feeding mechanism is provided at the tape feeding end, so that the tape is intermittently fed as a part is picked up by the head unit 5 described later.

  A head unit 5 for mounting electronic components is provided above the base 1. The head unit 5 is movable over the component supply unit 4 and the printed circuit board 3 positioned at the working position. In this embodiment, the head unit 5 is in the X-axis direction (the direction of the conveyor 2) and the Y-axis direction (on the horizontal plane). It is possible to move in a direction perpendicular to the X axis.

  That is, a pair of fixed rails 7 extending in the Y-axis direction and a ball screw shaft 8 that is rotationally driven by a Y-axis servo motor 9 are disposed on the base 1, and a head unit is disposed on the fixed rail 7. A support member 11 is disposed, and a nut portion 12 provided on the support member 11 is screwed onto the ball screw shaft 8. The support member 11 is provided with a guide member 13 extending in the X-axis direction and a ball screw shaft 14 driven by an X-axis servo motor 15 so that the head unit 5 can move on the guide member 13. A nut portion (not shown) held by the head unit 5 is screwed onto the ball screw shaft 14. Then, the ball screw shaft 8 is rotated by the operation of the Y-axis servo motor 9 to move the support member 11 in the Y-axis direction, and the ball screw shaft 14 is rotated by the operation of the X-axis servo motor 15 to thereby rotate the head unit 5. Moves in the X-axis direction with respect to the support member 11.

  The Y-axis servo motor 9 and the X-axis servo motor 15 are provided with position detecting means 10 and 16 each consisting of an encoder, whereby the operating position of the head unit 5 is detected. .

  The head unit 5 is equipped with a plurality of suction heads 20 having component suction nozzles at the tips. In this embodiment, eight suction heads 20 are arranged in a line in the X-axis direction. ing.

  Each suction head 20 can move in the Z-axis direction (vertical direction) and rotate around the R-axis (nozzle center axis) with respect to the frame of the head unit 5. It is driven by a servo motor. Further, the nozzles of the respective suction heads 20 are connected to negative pressure supply means via valves or the like so that negative pressure for component suction is supplied.

  In addition, the head unit 5 is provided with a pair of marks 22 for examining component misalignment of the component by the adsorption head 20. These marks 22 are arranged in a line on the suction head 20 on both outer sides (left and right outer sides in FIG. 2) of the suction heads 20 arranged in the X-axis direction as described above. It is provided toward the lower side so that imaging by the camera 23 is possible.

  The base 1 is further provided with a component recognition camera 23 between the conveyor 2 and one component supply unit 4 for imaging the component sucked by the suction heads 20. The component recognition camera 23 includes an illumination unit 23a having a light source composed of an LED or the like and a sensor body 23b. The sensor main body 23b is a CCD linear sensor in which CCD solid-state image sensors are arranged in parallel in the Y-axis direction (a direction orthogonal to the arrangement direction of the suction head 20), and is a slit in the Y-axis direction formed in the illumination unit 23a. The picked-up component image or the like is captured one-dimensionally via the.

  FIG. 3 is a block diagram showing a control system of the mounting machine.

  The mounting machine includes a well-known CPU that executes logical operations, a ROM that stores various programs for controlling the CPU in advance, a RAM that temporarily stores various data during operation of the apparatus, and the like. 30.

  The control device 30 includes a main control unit 31, a driver 32, an image processing unit 33, a calculation unit 34, and the like.

  The main control means 31 controls the operation of the mounting machine in an integrated manner, and controls the driving of the head unit 5 and the like via the driver 32 in order to execute the component mounting / mounting operation according to a program stored in advance. It is. In particular, after component suction, as will be described in detail later, the head unit 5 is driven and controlled to perform a component recognition operation for imaging the component sucked by each suction head 20 and the mark 22 by the component recognition camera 23, and The head unit 5 is driven and controlled so as to correct the mounting position of the component by the head unit 5 based on the component suction displacement amount obtained by the component recognition operation.

  The driver 32 drives and controls the head unit 5, and the servo motors 15 and 9 such as the X-axis and the Y-axis, and their position detection means 16 and 10 are connected to the driver 32. During the mounting operation, the driving of the servo motor 15 and the like is controlled by the main control means 31 through the driver 32.

  The image processing means 33 performs predetermined image processing on the image signal output from the component recognition camera 23.

  The calculation means 34 is configured to detect the positional relationship between the mark 22 (one mark 22) imaged by the board recognition camera 23 and each suction component in the component recognition operation on the image, and the previously stored mark 22 (the one mark). ) 22 and the positional relationship (theoretical positional relationship or positional relationship measured in advance; known information) of each suction head 20 to determine the suction displacement amount Δa of each suction component with respect to each suction head 20. At the same time, the distance between the marks 22 on the image (that is, the distance in the X-axis direction) is compared with a reference value (theoretical value or a value measured in advance) stored in advance. The movement error Δb of the head unit 5 in the X-axis direction is obtained.

  Next, the mounting operation by the mounting machine will be described with reference to the flowchart of FIG.

  When the mounting operation is started in the mounting machine, first, the printed circuit board 3 is carried along the conveyor 2 and positioned at the working position. At the same time, the head unit 5 is moved to the component supply unit 4. The first part is adsorbed and taken out from the tape feeder 4a (steps S1 and S2).

  Next, it is determined whether or not there are other parts to be picked up. If there are, there is a transition to step S1 to pick up the next part (step S3). On the other hand, when there are no other parts to be picked up (NO in step S3), the process proceeds to step S4, and the part recognition operation is executed.

  Specifically, the head unit 5 moves above the component recognition camera 23 at a constant speed, for example, in the direction indicated by an arrow (X-axis direction) in FIG. An image of the mark 22 in the main scanning direction (CCD solid-state imaging device arrangement direction; Y-axis direction) is sequentially taken in the sub-scanning direction (X-axis direction) and output to the image processing unit 33 as a predetermined image signal. . As a result, each suction component and both marks 22 are continuously captured as one image. At this time, imaging by the component recognition camera 23 is performed in synchronization with a pulse signal output from the position detection means 16 of the X-axis servomotor 15.

  Thus, when the head unit 5 passes completely over the component recognition camera 23 and the imaging of all the suction components and the marks 22 is completed, the positional relationship between the suction components and the mark 22 on the image, The amount of component suction deviation Δa with respect to each suction head 20 is obtained from the known positional relationship of the suction head 20, and the head unit 5 is moved in the X-axis direction from the interval between the marks 22 on the image and the reference value. An error Δb is obtained (step S5).

  Then, the head unit 5 moves to the first component mounting position, and components are mounted (step S6). At this time, the main control means 31 corrects the movement target position of the head unit 5 so as to correct the deviation and the like based on the suction deviation amount Δa of each component and the movement error Δb of the head unit 5.

  When the component is mounted, it is then determined whether there is another component to be mounted. If there is, the process proceeds to step S6 and the next component is mounted. On the other hand, when there are no other components to be mounted (NO in step S8), this flowchart ends.

  According to the mounting machine described above, the suction component of each suction head 20 and both marks 22 are continuously picked up as one image while moving the head unit 5 with respect to the component recognition camera 23 composed of a CCD linear sensor. Therefore, the adsorption deviation amount Δa of each component can be obtained for a plurality of adsorption components based on the single mark 22 as described above. Therefore, the correction of the mounting position of the components can be obtained with a rational configuration, and this has the effect of being able to satisfactorily meet the demand for downsizing of the head unit.

  In addition, a pair of marks 22 are provided on the head unit 5, and in the component recognition operation, the movement error Δb in the X-axis direction of the head unit 5 is obtained by examining the interval between the marks 22 on the image. Since the mounting position of the component by the head unit 5 is corrected based not only on the component adsorption deviation amount Δa but also on the movement error Δb, the effect that the component can be mounted on the printed circuit board 3 more accurately. There is.

  In this mounting machine, a pair of marks 22 are provided in the X-axis direction so as to obtain the movement error Δb of the head unit 5 in the X-axis direction. A component recognition camera composed of a CCD linear sensor capable of imaging the mark along with the movement of the head unit 5 in the Y-axis direction is installed on the base 1, and the head unit in the Y-axis direction is obtained by imaging both the marks with this camera. Similarly, a movement error of 5 may be obtained. If the mounting position of the component is corrected by the head unit 5 in consideration of the movement error in the Y-axis direction as described above, further improvement in mounting accuracy can be expected.

1 is a schematic plan view showing a surface mounter according to the present invention. It is a front view which shows a surface mounting machine. It is a block diagram which shows the control system of a surface mounting machine. It is a flowchart explaining mounting operation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Conveyor 3 Printed circuit board 4 Component supply part 5 Head unit 9 Y-axis servomotor 10, 16 Position detection means 15 X-axis servomotor 30 Control apparatus 31 Main control means 32 Driver 33 Image processing means 34 Calculation means

Claims (2)

Mounting position correction when electronic parts are picked up from a component supply unit by a movable head unit having a plurality of picking heads for mounting the parts, and the parts are mounted on a substrate positioned at a predetermined working position. A method,
By using a camera having a linear sensor provided on a base and moving the head unit onto the camera, the suction component by the suction head and the pair of marks provided on the head unit are continuously displayed as one image. To image,
From the image, the amount of suction displacement of the component is obtained based on the positional relationship between the mark and the suction component on the image and the positional relationship between the mark and the suction head, which is known information. Based on the upper interval and the reference value of the interval, find the movement error of the head unit,
A component mounting position correction method, wherein a component mounting position by the head unit is corrected based on the suction displacement amount and the movement error. In a surface mounter that adsorbs an electronic component from a component supply unit by a movable head unit having a plurality of adsorption heads for component mounting, and mounts the component on a substrate positioned at a predetermined work position.
  A pair of marks provided on the head unit;
  A camera that is disposed on a base and has a linear sensor capable of imaging the suction component by the suction head and the mark;
  Control that controls the drive of the head unit to perform a predetermined mounting operation and move the head unit onto the camera so that the suction component and the pair of marks by the suction head are continuously captured as one image. Means,
  From the captured image, the amount of suction displacement of the component is obtained based on the positional relationship between the mark and the suction component on the image and the positional relationship between the mark and the suction head, which is known information, and both marks Calculating means for obtaining a movement error of the head unit based on the interval on the image and the reference value of the interval,
  The surface mounting machine, wherein the control means is configured to correct a mounting position of a component by a head unit based on the suction displacement amount and the movement error obtained by the calculating means.

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