JP6055301B2 - Surface mount machine - Google Patents

Description

The present invention relates to a surface mounter that corrects a target sitting position of a head unit that has changed due to thermal expansion of a drive shaft in a surface mounter .

  Conventionally, in a component mounting apparatus having an XY driving device, a reference jig already measured by an external measuring instrument is placed on the mounting position of the circuit board, and a workpiece recognition camera attached to the mount head is used to mount the reference jig on the reference jig. There are some which correct the running accuracy of the X-axis and the Y-axis by measuring a plurality of observation points (see, for example, Patent Document 1).

  Specifically, from the position where the observation point origin coincides with the coordinate origin of the workpiece recognition camera, the reference jig uses the observation jig arranged in the X-axis direction and Y-axis direction on the reference jig as data. Is moved by the X-axis unit and the Y-axis unit, and the center of the observation point is obtained by image processing at each observation point. In this image processing, a deviation amount from the coordinate origin of the workpiece recognition camera is obtained, and the distortion of the machine coordinate system is corrected based on the deviation amount.

JP 2003-28615 A

  By the way, in the component mounting apparatus described in Patent Document 1, since a deviation amount is obtained at all the observation points arranged in the X-axis direction and the Y-axis direction, it takes a long time to perform the correction calculation. However, there is a problem that the production tact time when mounting components on the board is greatly affected. The reference jig described in Patent Document 1 is held after moving on the conveyor 14, and the position of the observation point origin 76 on the reference jig relative to the base 10 is the same as the observation point origin 76. The recognition is performed by the workpiece recognition camera 42 that is moved with reference to the coordinate origin of the workpiece recognition camera 42 that is difficult to match. Further, Patent Document 1 does not disclose how to obtain the positional relationship of the coordinate origin of the workpiece recognition camera 42 with respect to the base 10. For this reason, the coordinate origin of the workpiece recognition camera 42 is corrected based on the position of the observation point origin 76 on the reference jig. When the mounting operation is continued and the time elapses and the distortion changes in the X axis and the Y axis, it is necessary to carry in the reference jig again, which takes time. Further, since the coordinate origin of the workpiece recognition camera 42 is corrected based on the position of the observation point origin 76 on the reference jig, there is a problem that the correlation cannot be obtained.

The present invention has been made in view of such a problem, and an object of the present invention is to propose a surface mounter capable of calculating a correction coefficient with necessary and sufficient accuracy while minimizing the influence on the production tact time.

In order to achieve this object, according to the first aspect of the present invention, an electronic component mounting head unit that is movably supported with respect to a mounting machine body is moved through a drive shaft, and a predetermined mounting is performed by a conveying means. In a surface mounter that mounts electronic components by the head unit on a substrate transported to a work position, a plurality of reference marks attached to a fixing portion of the mounter body in a state associated with the mount work position An imaging unit that captures and recognizes the plurality of reference marks, a drive unit that moves the imaging unit along the drive axis to the plurality of reference marks, and a part of the plurality of reference marks The amount of thermal expansion change of the drive shaft is obtained using the coordinate position of the part of the reference marks obtained by imaging the mark by the imaging unit, and the actual amount of the head unit is determined according to the amount of thermal expansion change. And a control unit for calculating a correction coefficient for correcting the target coordinate position corresponding to the working position, the control unit includes a coordinate position of the reference mark of the part of said portion which has been acquired immediately of the reference mark When the difference value with respect to the coordinate position is equal to or larger than a predetermined allowable value, the remaining part of the plurality of reference marks following the part of the reference marks is imaged by the imaging unit, and the part and the remaining part The correction coefficient is newly calculated based on the coordinate positions of all the reference marks .

According to a second aspect of the present invention, an electronic component mounting head unit that is movably supported with respect to a mounting machine body is moved via a drive shaft, and the substrate is transported to a predetermined mounting work position by a transport unit. On the other hand, in the surface mounter for mounting electronic components by the head unit, a plurality of reference marks attached to the fixing portion of the mounting machine body in a state associated with the mounting work position, and the plurality of reference marks An image pickup unit that picks up and recognizes, a drive unit that moves the image pickup unit to the plurality of reference marks along the drive axis, and a part of the plurality of reference marks is picked up by the image pickup unit. The amount of change in thermal expansion of the drive shaft is obtained using the coordinate positions of the part of the reference marks obtained in this manner, and the target seat corresponding to the mounting work position of the head unit is determined according to the amount of change in thermal expansion. A control unit that calculates a correction coefficient for correcting the position, and the control unit divides the plurality of reference marks into at least two groups, and acquires the coordinate positions of the reference marks included in the current group. If the predetermined time has elapsed before, the coordinate position of the reference mark included in the next group of the current group is acquired, the coordinate position of the reference mark included in the current group, and the reference position included in the next group The amount of thermal expansion change of the drive shaft is obtained based on the coordinate position of the mark, and the correction coefficient is calculated according to the amount of thermal expansion change.
According to a third aspect of the present invention, an electronic component mounting head unit that is movably supported with respect to a mounting machine body is moved via a drive shaft, and the substrate is transported to a predetermined mounting work position by a transport means. On the other hand, in a surface mounter that mounts electronic components by the head unit,
A plurality of reference marks attached to a fixing portion of the mounting machine body in a state associated with the mounting work position, an imaging unit that captures and recognizes the plurality of reference marks, and the plurality of reference marks The drive unit that moves the imaging unit along the drive axis, and the coordinate position of the some reference marks obtained by imaging some reference marks among the plurality of reference marks by the imaging unit. A control unit that obtains a thermal expansion change amount of the drive shaft and calculates a correction coefficient for correcting a target coordinate position corresponding to the mounting work position of the head unit according to the thermal expansion change amount; The plurality of reference marks are divided into at least two groups, and after a predetermined time has elapsed since the coordinate position of the reference mark included in the current group is acquired, the reference included in the current group is included. Obtaining the coordinate position of the mark anew and obtaining the coordinate position of the reference mark included in the next group of the current group, obtaining the thermal expansion change amount of the drive shaft based on the coordinate position of all the reference marks, The correction coefficient is calculated according to the thermal expansion change amount.

In the surface mounting machine according to the aspect of the invention, the controller may be configured such that a difference value between a coordinate position of the part of the reference marks and a coordinate position of the part of the reference marks acquired immediately before the predetermined reference value is greater than a predetermined allowable value. Is smaller, the correction coefficient calculated immediately before is used.

The present invention is characterized in that, in the surface mounter, the control unit changes the number of acquisition of the coordinate position of the reference mark when the imaging unit recognizes the image.

The present invention provides the surface mounting machine, wherein the control unit reduces the default number of reference marks when the thermal change of the drive shaft is small, and defaults when the thermal change of the drive shaft is large. The number of the reference marks obtained is increased.

  According to the present invention, instead of recognizing all of the plurality of reference marks, a part of the plurality of reference marks is recognized, and the thermal expansion change amount of the drive shaft is determined using the coordinate position of the part of the reference marks. By calculating a correction coefficient that corrects the target coordinate position corresponding to the mounting work position of the head unit according to the obtained thermal expansion change amount, the time to calculate the correction coefficient can be shortened, and thus the production tact time It is possible to calculate a correction coefficient with necessary and sufficient accuracy while minimizing the influence on the image.

It is a top view which shows the structure of the component mounting machine in 1st Embodiment. It is a front view which shows the structure of a component mounting machine. It is a principal part enlarged view which shows the structure of a head unit. It is a block diagram which shows the structure of the control system of a component mounting machine. It is a flowchart with which explanation of basic mounting operation is provided. It is a basic diagram with which it uses for description at the time of calculating | requiring a correction coefficient by comparing the recognition result of a part of reference mark in 1st Embodiment. It is a flowchart which shows the correction coefficient calculation process procedure in 1st Embodiment. It is an approximate line figure used for explanation at the time of recognizing a part of standard marks grouped in a 2nd embodiment in order for every predetermined time interval, and obtaining a correction coefficient. It is a flowchart which shows the correction coefficient calculation process procedure in 2nd Embodiment. It is a graph with which it uses for description of the state of change by the thermal expansion of a ball screw shaft in 3rd Embodiment. It is a flowchart which shows the correction coefficient calculation processing procedure in 3rd Embodiment.

(1) First Embodiment <Configuration of Electronic Component Mounting Machine>
As shown in FIG. 1 and FIG. 2, an electronic component mounting machine 100 as a surface mounting machine according to the present invention has a base 1, on which a conveyor 2 for transporting a printed circuit board is arranged. The board 3 is conveyed on the conveyor 2 and stopped at a predetermined mounting work position P. The conveyor 2 has a pair of frames 2a and 2b equipped with a conveyor belt. One frame 2a is configured as a fixed frame, and the other frame 2b is movable so that the distance between the frame 2a and the fixed frame 2a can be adjusted. It is configured as a frame.

  On the side of the conveyor 2 (upper and lower in the figure), component supply units 4 and 4 are arranged. The component supply unit 4 includes a plurality of rows of tape feeders 4a, and each tape feeder 4a stores and holds small pieces of electronic components such as ICs (Integrated Circuits), transistors, and capacitors at predetermined intervals. The tape is led out from the reel, and a ratchet type feed mechanism is provided at the tape feed end, and the tape is intermittently fed as the electronic component is picked up by the head unit 5 described later.

  Further, a head unit 5 for mounting components is provided above the base 1. The head unit 5 is movable in the X-axis direction (the direction of the conveyor 2) and the Y-axis direction (a direction orthogonal to the X-axis on the horizontal plane).

  That is, a pair of fixed rails 7 and 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 the 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 with 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, and the head unit 5 is movably held by the guide member 13. A nut portion (not shown) provided on the head unit 5 is screwed with the ball screw shaft 14. 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 support the head unit 5. It moves in the X-axis direction relative to the member 11.

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

As shown in FIG. 3, the head unit 5 is provided with a first nozzle member 21 and a second nozzle member 22 that adsorb electronic components. The first and second nozzle members 21 and 22 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, respectively. Operated by motors 17 and 18 and R-axis servo motors 19 and 20. Each of the servo motors 17 to 20 is provided with position detecting means 21a to 24a made of an encoder, and the operation positions of the first and second nozzle members 21 and 22 are detected by these. The first and second nozzle members 21 and 22 are connected to negative pressure supply means (not shown) via valves or the like, and negative pressure for component suction is applied to the first and second nozzle members 21 and 22 when necessary. Supplied.

  A substrate recognition camera 25 is attached to the front side of the head unit 5. The board recognition camera 25 as the imaging unit captures images of marks attached to the surface of the printed circuit board 3 at the time of mounting and images reference marks 40a to 40f attached to the frames 2a and 2b of the conveyor 2. . A cylindrical light-emitting body 26 made up of a large number of LEDs is fixed to the front end portion (lower end portion) of the substrate recognition camera 25, and light is emitted from the light-emitting body 26 during imaging, and the detection hole 27 of the light-emitting body 26 is detected. The image is taken into the board recognition camera 25 via

  The base 1 is provided with a component recognition camera 28 for recognizing the suction state of the electronic component sucked by the head unit 5. The component recognition camera 28 is disposed between the component supply unit 4 and the conveyor 2b. After the electronic component is picked up by the component supply unit 4, the head unit 5 is positioned at a predetermined position above the component recognition camera 28. The suction part is imaged by being moved.

The reference marks 40a, 40e, and 40c are provided at three positions on the fixed frame 2a of the conveyor 2 that are not deformed due to thermal expansion, and the reference marks 40d, 40b, and 40f are deformed due to thermal expansion. The reference marks 40a, 40e, and 40c are provided so as to oppose each other in the Y-axis direction at three positions on the movable frame 2b of the conveyor 2 that do not perform.

  Next, a control system of the electronic component mounting machine 100 will be described with reference to FIG. The electronic component mounting machine 100 is equipped with a control device 30 as a control unit having a CPU (Central Processing Unit) configuration. Y-axis servo motor 9, X-axis servo motor 15, Z-axis servo motors 17, 18 for each nozzle member 21, 22 of head unit 5, R-axis servo motors 19, 20 and position detection means 10, 16 for each servo motor , 21a to 24a, etc. are all electrically connected to the control device 30 and are collectively controlled by the control device 30.

  More specifically, the control device 30 includes a main arithmetic unit 32 having predetermined information for comprehensively controlling the operation of the electronic component mounting machine 100 and an axis control unit 31 controlled by the main arithmetic unit 32. The servo motors 17 to 20 are connected to the shaft control unit 31 of the control device 30.

  The axis control unit 31 and the main calculation unit 32 perform control to perform a predetermined mounting operation for mounting electronic components, and the head unit 5 to place the substrate recognition camera 25 at a predetermined imaging position with respect to the reference marks 40a to 40f. It also functions as a drive control means for moving.

  The control device 30 is provided with an image processing unit 33, and the board recognition camera 25 is connected to the image processing unit 33. That is, the image data captured by the board recognition camera 25 is subjected to predetermined image processing and output to the main calculation unit 32 so that the main calculation unit 32 recognizes the reference marks 40a to 40f. It is configured.

  The control device 30 is further provided with an expansion coefficient calculation unit 34, the expansion coefficient calculation unit 34 is connected to the main calculation unit 32 and the storage unit 35, and the storage unit 35 is further connected to the main calculation unit 32. Yes.

  When the main calculation unit 32 recognizes the reference marks 40a to 40f, the image data of the recognized reference marks 40a to 40f is output to the expansion rate calculation unit 34, and the expansion rate calculation unit 34 uses the reference mark 40a. The expansion coefficient is calculated based on the image data of ˜40f. Specifically, the reference marks 40a to 40f are imaged in advance by the substrate recognition camera 25 in an unheated state in the initial warm-up period immediately after the start of the electronic component mounting machine 100 (immediately after the start-up SW of the mounting machine is turned on). At the same time, the coordinate positions on the images of the reference marks 40a to 40f at this time are stored in the storage unit of the expansion coefficient calculation unit 34 as the reference coordinate positions. Thereafter, when there is a deviation between the coordinate position on the image of the reference marks 40a to 40f imaged by the substrate recognition camera 25 and the reference coordinate position stored in advance in the storage unit of the expansion coefficient calculation unit 34, The amount of deviation (error) is calculated as the amount of change in thermal expansion of the ball screw shafts 8 and 14, and the correction coefficient K corresponding to the expansion coefficient in the X-axis direction and the Y-axis direction is calculated in accordance with these amounts of change in thermal expansion. And stored in the storage unit 35.

  Note that the reference coordinate position does not necessarily have to be checked in an unheated state at the initial stage of the warm-up period, and the positions of the reference marks 40a to 40f are theoretically obtained based on the specifications of the ball screw shaft 8 and the like. It may be a value (theoretical reference coordinate position).

  When the head unit 5 is moved, the main calculation unit 32 uses the correction coefficient and the movement amount of the head unit 5 at the time of mounting as a target mounting position corresponding to the mounting work position of the electronic component, That is, the target coordinate position of the head unit 5 is corrected. As described above, the main calculation section 32 functions as a correction means in addition to the function as the drive control means described above.

<Basic mounting operation>
A basic mounting operation in the electronic component mounting machine 100 will be described. As shown in FIG. 5, the control device 30 of the electronic component mounting machine 100 enters from the start step of the routine RT1 and moves to the next step SP1, and the mounting process start command is not given by the operator's button operation or the like Ends without starting the mounting process. When a start instruction is given, the process proceeds to the next step SP2.

  Here, if an affirmative result is obtained, the control device 30 makes preparations such as component suction operation via the first and second nozzle members 21 and 22 of the head unit 5, and then proceeds to step SP2. In step SP2, the control device 30 moves the head unit 5 to the mounting work position P by the operation of the Y-axis servo motor 9 and the X-axis servo motor 15, and sucks it through the first and second nozzle members 21 and 22. The components are mounted on the printed circuit board 3 that is carried in and held at the mounting work position P. After the mounting operation of sequentially mounting a predetermined number of components on the printed circuit board 3 by repeating the suction and mounting by the first and second nozzle members 21 and 22, the printed circuit board 3 is carried out. After carrying out the operations of carrying in, mounting, and carrying out these printed circuit boards 3 on a predetermined number of printed circuit boards 3, the process proceeds to the next step SP3.

  In step SP3, the control device 30 uses the board recognition camera 25 attached integrally with the head unit 5 as shown in FIG. 6, for example, for the first time as (N-1) th (N is an integer of 2 or more). Is recognized by imaging all the reference marks 40a to 40f, and the process proceeds to the next step SP4. In this case, the control device 30 determines the coordinate positions (R1 (N-1), R2 (N-1), R3 (N-1), R4 (N-1), R5 ( N-1), R6 (N-1)) and the reference coordinate position with respect to this coordinate position, the amount of deviation (error) is calculated as the amount of change in thermal expansion of the ball screw shafts 8 and 14, and these heat A correction coefficient K for correcting the target coordinate position, which is the mounting work position P of the head unit 5, is calculated by a predetermined correction logic according to the expansion change amount, and the correction coefficient K is stored in the storage unit 35.

  In step SP4, the control device 30 corrects the head unit 5 based on the correction coefficient K by the operation of the Y-axis servo motor 9 and the X-axis servo motor 15, and sets the target coordinate position (mounting work position P) set for each component. After a predetermined number of parts are sequentially mounted on the printed circuit board 3 carried in and held at the mounting work position P via the first and second nozzle members 21 and 22, the mounting work is completed. After a series of operations for carrying out the printed circuit board 3 is performed on a predetermined number of printed circuit boards 3, the process proceeds to the next step SP5.

  In step SP5, the control device 30 performs the (N) th recognition operation that is next to the recognition operation in step SP3, and proceeds to the next step SP6. In this case, specifically, the control device 30 captures only some of the reference marks 40a, 40b, and 40c among the reference marks 40a to 40f, and coordinates positions (R1 (N), R2 ( N), R3 (N)) are coordinate positions (R1 (N-1), R2 (N-) on the images of the reference marks 40a, 40b, 40c based on the previous (N-1) th recognition operation. 1) After comparison with R3 (N-1)), a correction coefficient K for correcting the target coordinate position which is the mounting work position P of the head unit 5 is calculated according to the correction logic, and this correction coefficient K is stored. After storing in the unit 35, the same mounting operation as in step SP4 is performed in the next step SP6. Thereafter, a recognition operation similar to step SP3, a mounting operation similar to step SP4, a recognition operation similar to step SP5, a series of recognitions consisting of a mounting operation similar to step SP6, the calculation of the correction coefficient K, and the mounting operation, After N is increased by “2” until all the printed circuit boards 3 to be produced are mounted, the process ends.

  Here, a method of calculating the correction coefficient K based on the recognition operation of the reference marks 40a, 40b, and 40c at the (N) th time in step SP5 will be described in detail with reference to FIGS. In step SP11, the control device 30 sets “1” to the initial value i for recognizing the reference marks 40a to 40f, and then proceeds to the next step SP12.

  In step SP12, the control device 30 captures the coordinate position (Ri (N)) on the image by imaging the i-th reference mark (for example, the first reference mark 40a) set to the initial value i by the substrate recognition camera 25. Recognize and move to next step SP13.

  In step SP13, the control device 30 stores the coordinate position Ri (N) on the image, which is the recognition result of the i-th reference mark recognized in step SP12, in the storage unit 35, and proceeds to the next step SP14.

  In step SP14, the control device 30 determines m (three in this case as a part of all the reference marks 40a to 40f) necessary for calculating the correction coefficient K corresponding to the expansion rate of the ball screw shafts 8 and 14. It is determined whether or not the fiducial marks 40a to 40c are recognized. Here, when m reference marks are not captured and recognized, a negative result is obtained, and the control device 30 returns to step SP11, and steps SP11 to SP14 are performed until the m reference marks are captured and recognized. repeat. On the other hand, if m reference marks have been captured and recognized, an affirmative result is obtained, and the control device 30 proceeds to the next step SP15.

  In step SP15, the control device 30 determines the coordinate position R1 (N) to Rm (N) as the (N) th recognition result (for example, the coordinate position R1 (2) of the reference marks 40a, 40b, and 40c as the second recognition result. 2) to R3 (2)) and the coordinate position R1 (N-1) which is the recognition result of all the reference marks already acquired as the (N-1) th time by the step SP3 of FIG. 5 which is the previous recognition step. ) To Rn (N−1), the coordinate positions R1 (N−1) to Rm (N−1) (for example, the first recognition result less than the second one). The coordinate positions R1 (1) to R3 (1)) of certain reference marks 40a, 40b, and 40c are individually compared, and the difference (error) that is the difference value is calculated, and then the next step SP16. Move on.

  In step SP16, the control device 30 determines whether or not all the individual difference values calculated in step SP15 are below the first allowable value Q1. If a negative result is obtained here, this means that the amount of deviation (error) between the previous recognition result and the current recognition result is large, and it is necessary to recalculate the correction coefficient K from the beginning this time. At this time, the control device 30 proceeds to the next step SP17.

  In step SP17, the control device 30 repeatedly performs steps SP12 and SP13 from i = m + 1 to i = n, recognizes the remaining (N) th m + 1st to nth reference marks and coordinates as a recognition result. Positions R (m + 1) (N) to Rn (N) (for example, coordinate positions R4 (2) to R6 (2), which are recognition results of the second remaining reference marks 40d, 40e, and 40f) are acquired, and The process proceeds to step SP18.

  In step SP18, the control device 30 determines the coordinate positions R1 (N) to Rn (N), which are all the recognition results of the (N) th time (for example, the coordinate positions R1 of the reference marks 40a to 40f which are the second recognition results). 2) to R6 (2)), a correction coefficient K corresponding to the expansion rate of the ball screw shafts 8 and 14 is newly calculated, and the process proceeds to the next step SP19 to correct the target movement position of the head unit 22. After applying by using the correction coefficient K, the process proceeds to step SP20, the correction coefficient K is stored in the storage unit 35, and the process proceeds to the next step SP6.

  On the other hand, if a positive result is obtained in step SP16, this means that all the individual difference values calculated in step SP15 are below the first allowable value Q1, that is, the previous recognition result and the current recognition result. This means that it is not necessary to recognize the remaining (m + 1) th to nth reference marks, and at this time, the control device 30 performs the next step SP21. Move on.

  In step SP21, the control device 30 determines whether or not all the individual difference values calculated in step SP15 are less than the second allowable value Q2 (first allowable value Q1> second allowable value Q2). . If a positive result is obtained here, this means that all of the individual difference values calculated in step SP15 are lower than the second allowable value Q2 as well as the first allowable value Q1, that is, the previous recognition result. This means that the amount of deviation (error) between this and the current recognition result is extremely small, and it is not necessary to recalculate the correction coefficient K this time, and the previous correction coefficient K can be used. At this time, the control device 30 proceeds to the next step SP22.

  In step SP22, the control device 30 applies the (N-1) th correction coefficient K obtained in step 3 in the above-described routine RT1 to the correction of the target movement position of the head unit 22 as it is, and proceeds to step SP6.

  On the other hand, if a negative result is obtained in step SP21, this means that all the individual difference values calculated in step SP15 are below the first allowable value Q1, but below the second allowable value Q2. In other words, it is impossible to divert the previous correction coefficient K as it is, and it is necessary to recalculate the correction coefficient K. However, when calculating the correction coefficient K, a part of the previous recognition result Can be diverted, and at this time, the control device 30 proceeds to the next step SP23.

  In step SP23, the control device 30 determines the coordinate positions R1 (N−1) ˜ that are recognition results of all the reference marks already acquired as the (N−1) th time in step SP3 of FIG. 5 which is the previous recognition step. Among Rn (N−1), the coordinate positions R (m + 1) (N−1) to Rn (N−1) which are the recognition results from the (m + 1) th to the nth (for example, the first time less than the second time) The coordinate positions R4 (1) to R6 (1)) of the reference marks 40d, 40e, and 40f, which are recognition results, and the coordinate positions R1 (N) to Rm (N) (for example, the current (N) th recognition result) The correction coefficient K corresponding to the expansion rate of the ball screw shafts 8 and 14 is calculated using the coordinate positions R1 (2) to R3 (2) of the reference marks 40a, 40b, and 40c that are the second recognition results. Then, the process proceeds to the next step SP19.

  In step SP19, the control device 30 applies the correction coefficient K obtained in step SP23 to the correction of the target movement position of the head unit 22, and then moves to the next step SP20 and stores the correction coefficient K in the storage unit 35. Save and move to next step SP6.

  In this way, the control device 30 has coordinate positions R1 (N) to Rm () that are the recognition results of the (N) th three reference marks 40a, 40b, and 40c among the six reference marks 40a to 40f in total. N) and (N-1) coordinate positions R1 (N-1) to Rm (N) which are the recognition results of the corresponding three reference marks 40a, 40b, 40c among all the six reference marks recognized for the first time. When the difference value from -1) is less than the allowable value Q2, the correction coefficient K obtained for the (N-1) th time can be applied as it is in the mounting operation of step SP6.

  In addition, when the difference value is not lower than the allowable value Q2 but lower than the allowable value Q1, the control device 30 determines the coordinates that are the recognition results of the three reference marks 40a, 40b, and 40c acquired in the (N) th time. Positions R1 (N) to Rm (N), and coordinate positions R (m + 1) (N−1) to Rn (m + 1) to (N−1) th already obtained recognition results from the (m + 1) th to the nth. The correction coefficient K newly calculated using (N-1) can be applied in the mounting operation of step SP6.

  That is, in the electronic component mounting machine 100, the coordinate positions R1 (N) to Rm (N), which are the recognition results of the (N) th three reference marks 40a, 40b, and 40c, and the (N-1) th three pieces. Has already been calculated based on the comparison result between the difference values between the coordinate positions R1 (N-1) to Rm (N-1), which are the recognition results of the reference marks 40a, 40b, and 40c, and the allowable values Q1 and Q2. The reliability of the most recent correction coefficient K is determined. At this time, if the reliability of the correction coefficient K is low, the correction coefficient K is recalculated. If the reliability of the correction coefficient K is high, the remaining three reference marks 40d, 40e, and 40f are recognized in the (N) th recognition. Since the correction coefficient K can be obtained using only the recognition results of only the three fiducial marks 40a, 40b, and 40c without performing recognition, correction with necessary and sufficient accuracy while maintaining the reliability of the correction coefficient K is possible. The coefficient K can be easily calculated, and thus the influence on the production tact time can be reduced.

(2) Second Embodiment Regarding the electronic component mounting machine 100 according to the second embodiment, the overall mechanical configuration, the circuit configuration of the control system, and the basic mounting operation of the control device 30 will be described. Since this is the same as the first embodiment, the description thereof is omitted here. On the other hand, in the second embodiment corresponding to the (N−1) th (N = 2, 4, 6, 8,...) Recognition operation in step SP3 of the routine RT1 of the first embodiment ( N) recognition operation of the first time (N = 1, 3, 5,...) And the second corresponding to the (N) th time (N = 2, 4, 6, 8,...) In step SP5. Since the (N + 1) -th recognition operation (N = 1, 3, 5,...) Of the embodiment is different from that of the first embodiment, the recognition operations and correction coefficients of the reference marks 40a to 40f are different. The method for calculating K will be described in detail below with reference to FIGS.

  The flowchart of FIG. 9 is a flowchart for recognizing the reference marks 40a to 40f and calculating and storing the correction coefficient K. After the start instruction of the mounting process is given, the control device 30 carries in and holds the printed circuit board 3 to the mounting work position P, mounts the component by applying the correction coefficient K stored in the storage unit 35, and performs this mounting work. After finishing the above, a series of operations for unloading the printed circuit board 3 is performed on the number of printed circuit boards 3 planned for production. During this time, the control device 30 executes the flowchart of FIG. 9 in parallel, and updates the correction coefficient K stored in the storage unit 35.

  The Nth (N = 1, 3, 5, 7,...) And N + 1th (N = 1, 3, 5, 7,...) Recognition operations in the flowchart of FIG. , And at a predetermined timing after the start of mounting production, during the carry-out and carry-in of the printed circuit board 3 or during component mounting. After mounting production is started, in step SP31, the control device 30 groups the six reference marks 40a to 40f into a plurality of groups, and sets N as an initial value “1” and proceeds to the next step SP32.

  Here, the grouping of the six reference marks 40a to 40f into a plurality of groups includes a method of dividing the reference marks 40a, 40b and 40c into a first group and a second group of the reference marks 40d, 40e and 40f, and a reference mark. A method of dividing the first group of 40a and 40b, the second group of reference marks 40c and 40d, and the third group of reference marks 40e and 40f can be considered. However, here, for convenience of explanation, a case will be described in which the reference marks 40a, 40b, and 40c are divided into a first group (first group) and a second group of reference marks 40d, 40e, and 40f (next group).

  In step SP32, the control device 30 includes m (in this case, for example, m = 3) included in the first group to be recognized first in the (N) th time (N = 1, 3, 5, 7,...). ) Are recognized by imaging with the substrate recognition camera 25 (FIG. 8), and the process proceeds to the next step SP33.

  In step SP33, the control device 30 determines the coordinate positions R1 (N) to Rm (N) that are the current ((N) th) recognition results (for example, the coordinates of the reference marks 40a, 40b, and 40c that are the first recognition results). The positions R1 (1) to R3 (1)) are stored in the storage unit 35, and the process proceeds to the next step SP34.

  In step SP34, the control device 30 determines whether or not a predetermined time or more has elapsed after performing the mounting operation after recognizing the current ((N) th) m reference marks 40a, 40b, and 40c. The time is counted by a timer (not shown) built in 32. If a negative result is obtained here, this means that the predetermined time or more has not elapsed since the recognition of the m reference marks 40a, 40b, 40c this time ((N) th). And the current ((N + 1) th (N = 1, 3, 5, 7,...)) Recognition means that there is almost no change in the expansion rate of the ball screw shafts 8 and 14. At this time, the control device 30 proceeds to the next step SP35.

  In step SP35, the control device 30 recognizes the coordinate positions R1 (N) to Rm (N) that are the recognition results of the three reference marks 40a, 40b, and 40c acquired at the (N) th time, and at the (N + 1) th time recognition. Coordinate positions that are recognition results from the (m + 1) th to the nth by imaging the m + 1 to n (in this case, n = 6) reference marks 40d, 40e, and 40f included in the second group by the substrate recognition camera 25. R (m + 1) (N + 1) to Rn (N + 1) are acquired (FIG. 8), and the process proceeds to the next step SP36.

  In step SP36, the control device 30 determines the coordinate positions R1 (N) to Rm (N) as the recognition results of the three reference marks 40a, 40b, and 40c acquired for the (N) th time, and the (m + 1) th to nth. The correction coefficient K is calculated using the coordinate positions R (m + 1) (N + 1) to Rn (N + 1) as the recognition results (FIG. 8), and the correction coefficient K is used for correcting the target movement position of the head unit 22. Then, the process proceeds to the next step SP37, the correction coefficient K is stored in the storage unit 35, and the process proceeds to the next step SP38.

  In step SP38, it is determined whether or not the mounting production on the printed circuit board 3 is completed. If not, the process proceeds to step SP39, and after a predetermined time, N is increased by a value “2” and then the process proceeds to step SP32. . When the component is mounted by applying the correction coefficient K stored in the storage unit 35, the control device 30 corrects the target movement positions of the nozzle members 21 and 22 of the head unit 5 by the correction obtained in step SP40 and step SP41. A coefficient K is used. If it is determined in step SP38 that the mounting production is finished, the program is finished.

  On the other hand, if a positive result is obtained in step SP34, this means that a predetermined time or more has elapsed since the recognition of the m reference marks 40a, 40b, 40c this time ((N) th). This means that there is a high possibility that the expansion rate of the ball screw shafts 8 and 14 will greatly change between the current ((N) th) recognition and the next ((N + 1) th) recognition. At this time, the control device 30 proceeds to the next step SP40.

  In step SP40, the control device 30 recognizes the coordinate positions R (1) (N + 1) to Rn (N + 1) (for example, (N + 1) th recognition) as the recognition results of the (N + 1) th first to nth reference marks. After obtaining the coordinate positions R1 (N + 1) to R6 (N + 1) of the reference marks 40a to 40f as a result, the process proceeds to the next step SP41, using all these coordinate positions R1 (N + 1) to R6 (N + 1)). A correction coefficient K corresponding to the expansion rate of the ball screw shafts 8 and 14 is newly calculated, and the process proceeds to step SP38 through the next step SP37.

  In this way, the control device 30 divides the reference mark 40a to 40f into the first group of the reference marks 40a, 40b, and 40c and the second group of the reference marks 40d, 40e, and 40f from among the six reference marks 40a to 40f. If the predetermined time or more has not passed since the acquisition of the coordinate positions R1 (N) to Rm (N) as the recognition results of the first group of reference marks 40a, 40b, 40c acquired at the time of recognition, Since it can be considered that there is almost no change in the expansion rate of the ball screw shafts 8 and 14 between the recognition at the (N) th time and the next ((N + 1) th) recognition, (N) The coordinate positions R1 (N) to Rm (N) that are the recognition results of the three reference marks 40a, 40b, and 40c acquired for the second time, and the three reference marks 40d, 40e, and 40f acquired for the (N + 1) th time. Recognition result Certain coordinate position R (m + 1) (N + 1) ~Rn (N + 1) and can calculate the correction coefficient K with all.

  That is, the control device 30 does not need to recognize all of the six reference marks 40a to 40f at a time and obtain the correction coefficient K, and the reference mark 40a included in one group divided into two at one time. ˜40c or reference marks 40d˜40f only need to be recognized. As a result, the electronic component mounting machine 100 can reduce the number of times of recognition of the reference marks 40a to 40f that should be recognized at one time when calculating the correction coefficient K. Therefore, it is necessary and sufficient while maintaining the reliability of the correction coefficient K. Therefore, it is possible to easily calculate the correction coefficient K with high accuracy, and to reduce the influence on the production tact time.

(3) Third Embodiment Regarding the electronic component mounting machine 100 in the third embodiment, the overall mechanical configuration, the circuit configuration of the control system, and the basic mounting operation of the control device 30 are the second. Therefore, the description thereof will be omitted here, and the recognition operation of the reference marks 40a to 40f and the calculation method of the correction coefficient K will be described in detail below with reference to FIGS.

  As shown in FIG. 10, as the number of reference mark recognition times for recognizing the reference marks 40a to 40f increases, the axis of the shaft due to the friction of the ball screw shafts 8 and 14 that drive the head unit 5 in the X axis direction and the Y axis direction is increased. It is generally known that the degree of elongation / strain (S) gradually increases, and if the number of times exceeds a predetermined number, the degree of elongation / strain (S) of the shaft saturates and does not change. Since the first recognition is performed immediately after the start of mounting production, N at the origin in FIG.

  Here, for example, the section A1 in which the reference mark recognition number (N) is 0 to a, the reference mark recognition number (N) is a + 1 to b, the section B, and the reference mark recognition number (N) is b + 1. When section A2 is set to section A2, the change due to the thermal expansion of the ball screw shafts 8 and 14 is small in the sections A1 and A2, and the change due to the thermal expansion of the ball screw shafts 8 and 14 is relatively linear in the section B. It ’s big. Therefore, the number of reference marks 40a to 40f to be recognized at the time of reference mark recognition is reduced at the timings of sections A1 and A2, and the number of reference marks 40a to 40f to be recognized at the time of reference mark recognition is increased at the timing of section B. To change dynamically. The reference mark recognition operation using this concept will be described below.

  As shown in FIG. 11, after a mounting production start command is given, the program starts, and in step SP51, the control device 30 performs the (N-1) th (N = 1, 2, 3, 4,... N Is the default number m for recognizing a predetermined reference mark at the time of recognition 1) (if N = 1 immediately after the start of mounting production, the default number m at the 0th time which does not actually exist is 3 for example. And the process proceeds to the next step SP52. For example, in this case, since the reference marks 40a to 40f are a total of six, it is assumed that half of the reference marks 40a to 40f are determined as the default number m (in this case, m = 3) necessary for calculating the correction coefficient K. However, the number m may be two or four.

  In step SP52, the control device 30 sets “1” to the initial value i for recognizing the reference marks 40a to 40f, and then proceeds to the next step SP53.

  In step SP53, the control device 30 recognizes the i-th reference mark (for example, the first reference mark 40a) set to the initial value i by imaging with the substrate recognition camera 25, and proceeds to the next step SP54.

  In step SP54, the control device 30 stores the coordinate position Ri (N), which is the recognition result of the i-th reference mark obtained by imaging with the board recognition camera 25, in the storage unit 35, and proceeds to the next step SP55.

  In step SP55, the control device 30 determines whether m (three in this case) reference marks necessary for calculating the correction coefficient K corresponding to the expansion rates of the ball screw shafts 8 and 14 are recognized. judge. Here, if m reference marks cannot be recognized, a negative result is obtained, and the control device 30 returns to step SP52 and repeats steps SP52 to SP55 until the recognition of m reference marks is completed. On the other hand, if m reference marks have been recognized, a positive result is obtained, and the control device 30 proceeds to the next step SP56.

  In step SP56, the control device 30 determines whether or not the current reference mark recognition count (N) is the section A (sections A1 and A2), and when an affirmative result is obtained, the control apparatus 30 proceeds to the next step SP57, It is determined whether or not the reference mark recognition count (N) is the section A1. If a positive result is obtained here, the control device 30 moves to the next step SP58, and the reference mark recognition frequency (N) is the section A1, and the change due to the thermal expansion of the ball screw shafts 8 and 14 is small. The default number m for recognizing is reduced by “1”, and the process proceeds to the next step SP61.

  In step SP61, the control device 30 reduces the default number m when recognizing the reference mark by “1”, and therefore, the recognition result of the two reference marks 40a and 40b acquired this time ((N) th time). The coordinate positions R1 (N) to R2 (N) and the coordinate positions R (3) (N-1) which are the third to sixth recognition results already acquired (the (N-1) th time). ) To R6 (N−1), a new correction coefficient K is calculated, the process proceeds to the next step SP62, the correction coefficient K is stored in the storage unit 35, and the process proceeds to the next step SP63.

  In step SP63, it is determined whether or not the mounting production on the printed circuit board 3 is finished. If not finished, after a predetermined time has passed in step SP64, N is increased by a value “1” and the process proceeds to step SP51. The control device 30 uses the correction coefficient K obtained in step SP61 to correct the target movement position of the head unit 22 when mounting the component using the correction coefficient K stored in the storage unit 35. If it is determined in step SP63 that the mounting production has ended, the control device 30 ends the program.

  On the other hand, if a negative result is obtained in step SP57, this means that the current reference mark recognition count (N) is the section A2, and at this time, the control device 30 moves to the next step SP59, Since the reference mark recognition frequency (N) is the section A2 and is in a saturated state in which there is almost no change due to thermal expansion of the ball screw shafts 8 and 14, the default number m when recognizing the reference mark is reduced by “2”. Control goes to the next step SP61.

  In step SP61, the control device 30 has reduced the default number m for recognizing the reference mark by “2”, so that the coordinate position which is the recognition result of the one reference mark 40a acquired this time ((N) th time). R1 (N) and the coordinate positions R (2) (N-1) to R6 (N-1) which are the second to sixth recognition results already acquired (the (N-1) th time). ) And a new correction coefficient K is calculated, and the process proceeds to the next step SP62.

  On the other hand, if a negative result is obtained in step SP56, this means that the current reference mark recognition count (N) is the section B. At this time, the control device 30 moves to the next step SP60, and the reference mark is detected. Since the number of times of recognition (N) is section B and the change due to thermal expansion of the ball screw shafts 8 and 14 is large, the default number m for recognizing the reference mark is increased by “2”, and the process proceeds to the next step SP61.

  In step SP61, the control device 30 has increased the default number m when recognizing the reference mark by “2”, so that the recognition results of the five reference marks 40a to 40e acquired this time ((N) th time) are obtained. Using the coordinate positions R1 (N) to R5 (N) and the coordinate position R6 (N-1), which is the sixth recognition result already acquired (the (N-1) th) time, is newly used. The correction coefficient K is calculated, and the process proceeds to the next step SP62.

  As described above, when the reference mark recognition count is the timing of the section A1 in which the change due to the thermal expansion of the ball screw shafts 8 and 14 is small, the section B in which the change due to the thermal expansion of the ball screw shafts 8 and 14 is large. The default number m for recognizing the reference mark is dynamically increased or decreased depending on the timing of the section A2 in which there is almost no change due to thermal expansion of the ball screw shafts 8 and 14.

  As a result, when the change due to thermal expansion of the ball screw shafts 8 and 14 is small or almost absent, even if the default number m of reference marks recognized this time is reduced and the correction coefficient K is obtained, sufficient correction capability is obtained. On the other hand, when the change due to the thermal expansion of the ball screw shafts 8 and 14 is large, the correction coefficient K having sufficient correction capability can be obtained by increasing the default number m of the reference marks recognized this time to obtain the correction coefficient K. You can get it.

(4) Other Embodiments In the above-described first embodiment, m pieces (in this case) necessary for calculating and calculating the correction coefficient K among the six reference marks 40a to 40f in total in step SP14. Although the reference mark 40a, 40b, 40c is recognized by imaging, the present invention is not limited to this, and the correction coefficient K is calculated such as two or four. You may make it change according to the certainty of judgment.

  In the above-described third embodiment, the case where the number of reference marks acquired is dynamically changed has been described. However, the present invention is not limited to this, and steps SP11 to SP11 in the first embodiment are performed. The number of m reference marks recognized in step SP14 is dynamically changed as in the third embodiment, or the number of m reference marks recognized in step SP32 in the second embodiment is changed to the first number. It may be changed dynamically as in the third embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Component mounting system 6, 8, 10 ... Component mounting apparatus (surface mounting machine), 12 ... Reflow apparatus, 16 ... Host computer, 20a ... 1st board | substrate conveyance conveyor, 20b ... 2nd board | substrate conveyance conveyor, 22a ... Front side Head unit, 22b ... rear head unit, 23 ... suction head, 24a ... front part supply unit 24a, 24b ... rear part supply unit, 25 ... tape feeder, 30 ... main control unit, 31 ... drive control unit, 32 ... Storage unit 34 ... Communication unit 35 ... Imaging control and image processing unit 36 ... Display unit 38 ... Input unit 50 ... Switching conveyor 50a ... Front lane 50b ... Rear lane

Claims (6)

An electronic component mounting head unit that is movably supported with respect to the mounting machine main body is moved via a drive shaft, and the electronic component is moved by the head unit to a substrate that is transported to a predetermined mounting work position by a transport unit. In the surface mounter that mounts
A plurality of reference marks attached to a fixing portion of the mounting machine body in a state associated with the mounting work position;
An imaging unit that captures and recognizes the plurality of reference marks;
A drive unit that moves the imaging unit along the drive axis to the plurality of reference marks;
The amount of thermal expansion change of the drive shaft is determined using the coordinate position of the part of the reference marks obtained by imaging some of the plurality of reference marks by the imaging unit, and the amount of thermal expansion change and a control unit for calculating a correction coefficient for correcting the target coordinate position corresponding to the mounting work position of the head unit in accordance with,
When the difference value between the coordinate position of the part of the reference marks and the coordinate position of the part of the reference marks acquired immediately before the control part is equal to or greater than a predetermined allowable value, the control unit The remaining portions of the plurality of reference marks subsequent to the reference marks of the portion are also imaged by the imaging unit, and the correction coefficient is newly calculated based on the coordinate positions of all the reference marks of the part and the remaining portions. Surface mount machine. An electronic component mounting head unit that is movably supported with respect to the mounting machine main body is moved via a drive shaft, and the electronic component is moved by the head unit to a substrate that is transported to a predetermined mounting work position by a transport unit. In the surface mounter that mounts
A plurality of reference marks attached to a fixing portion of the mounting machine body in a state associated with the mounting work position;
An imaging unit that captures and recognizes the plurality of reference marks;
A drive unit that moves the imaging unit along the drive axis to the plurality of reference marks;
The amount of thermal expansion change of the drive shaft is determined using the coordinate position of the part of the reference marks obtained by imaging some of the plurality of reference marks by the imaging unit, and the amount of thermal expansion change And a control unit that calculates a correction coefficient for correcting a target coordinate position corresponding to the mounting work position of the head unit according to
With
The control unit divides the plurality of fiducial marks into at least two or more groups, and if a predetermined time has not passed since the coordinate position of the fiducial mark included in the current group is acquired, The coordinate position of the reference mark included in the current group is acquired, and the thermal expansion change of the drive shaft is based on the coordinate position of the reference mark included in the current group and the coordinate position of the reference mark included in the next group. A surface mounter characterized in that an amount is obtained and the correction coefficient is calculated in accordance with the amount of change in thermal expansion . An electronic component mounting head unit that is movably supported with respect to the mounting machine main body is moved via a drive shaft, and the electronic component is moved by the head unit to a substrate that is transported to a predetermined mounting work position by a transport unit. In the surface mounter that mounts
A plurality of reference marks attached to a fixing portion of the mounting machine body in a state associated with the mounting work position;
An imaging unit that captures and recognizes the plurality of reference marks;
A drive unit that moves the imaging unit along the drive axis to the plurality of reference marks;
The amount of thermal expansion change of the drive shaft is determined using the coordinate position of the part of the reference marks obtained by imaging some of the plurality of reference marks by the imaging unit, and the amount of thermal expansion change And a control unit that calculates a correction coefficient for correcting a target coordinate position corresponding to the mounting work position of the head unit according to
With
The control unit divides the plurality of reference marks into at least two or more groups, and if a predetermined time has elapsed after acquiring the coordinate positions of the reference marks included in the current group, the control part includes the reference marks. The reference position of the reference mark included in the next group of the current group, and the thermal expansion change amount of the drive shaft based on the coordinate positions of all the reference marks. A surface mounting machine characterized in that the correction coefficient is calculated according to the amount of change in thermal expansion . When the difference value between the coordinate position of the part of the reference marks and the coordinate position of the part of the reference marks acquired immediately before is smaller than a predetermined allowable value, the control unit calculates the correction calculated immediately before surface mounter according to any one of claims 1 to 3, characterized by using the coefficient. The surface mounter according to claim 4 , wherein the control unit changes the number of acquired coordinate positions of the reference mark when the image pickup unit picks up and recognizes the image. The control unit reduces the default reference mark acquisition number when the thermal change of the drive shaft is small, and increases the default reference mark acquisition number when the drive shaft thermal change is large. The surface mounter according to claim 5 .

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