JP2017195264A - Component mounting device, component mounting method, component mounting device control program and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably perform a component mounting operation in a short tact time by adjusting a performance interval of correction processing for correcting movement of a head unit with high accuracy.SOLUTION: A component mounting device comprises: a head unit for mounting a component on a substrate; a head drive mechanism for driving the head unit; an imaging part for imaging a reference mark fixed on a preset position; and a control unit for controlling the head drive mechanism to control mounting of the component on the substrate by the head unit. The control unit includes: a correction processing part which intermittently executes correction processing for correcting movement of the head unit by the head drive mechanism based on temporal change of positional information of the reference mark imaged by the imaging part while performing mounting of the component; and an interval adjustment part for adjusting a performance interval of the correction processing depending on variation of the temporal change.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a component mounting technique for mounting a component on a substrate by a head unit.

  In the component mounting apparatus, the control unit controls the movement of the head unit according to the mounting program, and the component is mounted on the board by the head unit. In the process of continuously executing the component mounting operation by moving the head unit in this manner, the temperature in the component mounting apparatus may increase, leading to a decrease in component mounting accuracy. The reason is as follows. In the component mounting apparatus, a head driving mechanism is provided to drive the head unit. However, the temperature rises due to frictional heat generated as the head unit moves. As a result, thermal displacement occurs due to thermal expansion of the constituent members of the head drive mechanism, resulting in an error in the positional accuracy of the head unit, which is one of the causes of a decrease in mounting accuracy. In order to solve this problem, the component mounting apparatus executes a correction process for correcting an error in position accuracy due to such thermal displacement while repeating the component mounting operation. However, since the temperature rise is saturated during the component mounting operation and the thermal displacement is saturated, it is unreasonable to always execute the correction process at a constant interval.

  Therefore, for example, in the device described in Patent Document 1, correction processing is performed at each first predetermined interval in the initial stage of operation, while the second longer than the first predetermined interval after a predetermined time after operation has started. It has been proposed to perform correction processing at predetermined intervals. In Patent Document 1, the first predetermined interval is set to a time required for one or two mounting operations, while the second predetermined interval is set to a time required for 10 to 20 mounting operations. It is exemplified.

JP 2013-175557 A

  In the above-described conventional apparatus, since the error occurring in the component mounting apparatus is only estimated based on time or the number of mounting operations, the execution interval of the correction process is not necessarily appropriate. May cause excessive tact time.

  The present invention has been made in view of the above problems, and by adjusting the execution interval of the correction processing for correcting the movement of the head unit with high accuracy, the component mounting operation can be stably performed in a short tact time. The purpose is to provide component mounting technology.

  1st aspect of this invention is a component mounting apparatus, Comprising: The head unit which mounts components on a board | substrate, the head drive mechanism which drives a head unit, and the imaging which images the reference mark fixed to the preset position And a control unit that controls the head drive mechanism to control the mounting of the component on the board by the head unit, and the control unit is configured to perform the reference imaging performed by the imaging unit while mounting the component. A correction processing unit that intermittently executes correction processing for correcting the movement of the head unit by the head driving mechanism based on a change with time in the mark position information, and an adjustment processing execution interval that is adjusted according to the amount of change with time. And an interval adjusting unit.

  According to a second aspect of the present invention, there is provided a component mounting method in which a head unit is moved and a component is mounted on a substrate by the head unit, and the component is placed at a preset position while the component is repeatedly mounted. A step of intermittently executing a correction process for obtaining a time-dependent change in the position information of the reference mark from an image of the reference mark obtained by imaging the fixed reference mark and correcting the movement of the head unit based on the time-dependent change; And a step of adjusting the execution interval of the correction process in accordance with the amount of change with time.

  According to a third aspect of the present invention, there is provided a control program for a component mounting apparatus that moves a head unit and mounts a component on a board by the head unit, and is set in advance while repeatedly mounting the component. The correction process for obtaining the time-dependent change of the position information of the reference mark from the image of the reference mark obtained by imaging the reference mark fixed at the fixed position and correcting the movement of the head unit based on the change over time is intermittently performed. The present invention is characterized in that a computer realizes a correction function to be executed and an interval adjustment function for adjusting an execution interval of correction processing in accordance with a variation amount with time.

  The fourth aspect of the present invention is characterized in that the control program is recorded.

  In the invention configured as described above, an error may occur in the positional accuracy of the head unit due to thermal displacement while the components are being mounted, but since the correction processing is intermittently performed, the head unit is It can be moved to an appropriate position, and the component mounting operation can be executed with high accuracy and stability.

  In addition, a change with time is acquired in order to perform the correction process. The change with time varies greatly while the thermal displacement is relatively large, while the amount of change decreases when the thermal displacement is saturated. Thus, the characteristics of thermal displacement are closely related to the amount of change over time. Therefore, in the present invention, the correction processing execution interval is adjusted based on the variation amount with time, thereby performing correction processing according to the characteristics of the thermal displacement and optimizing the correction processing execution interval. For this reason, the execution of excessive correction processing is eliminated, and the tact time is shortened.

  Here, in consideration of the relationship between the above-described characteristics of thermal displacement and the amount of change over time, it is desirable to increase the execution interval as the amount of change decreases, thereby effectively reducing the tact time. be able to.

  In addition, since the execution interval is extended in multiple stages according to the fluctuation amount, that is, the execution interval is increased as the fluctuation amount becomes smaller, it is possible to adjust the execution interval of the correction process finely corresponding to the characteristics of the thermal displacement. As a result, the tact time can be further effectively shortened.

  When the component mounting operation is stopped, the interior of the component mounting apparatus changes from a warm state (a state where the thermal displacement is saturated or almost saturated) to a cold state (a state where the thermal displacement becomes unsaturated) over time. State). Therefore, a stop time measurement unit that measures the stop time when component mounting is stopped is provided, and if the stop time measured by the stop time measurement unit exceeds a certain value, it is determined that the state has shifted to the cold state, and correction is made. You may comprise so that the execution interval of a process may be narrowed. Thereby, the correction process immediately after restarting the mounting of components can be executed at intervals corresponding to the cold state, and the component mounting work can be performed with high accuracy even immediately after the restart.

  Furthermore, the number of fiducial marks can be set arbitrarily, but by providing a plurality of fiducial marks at different positions, the thermal displacement at each part in the component mounting apparatus can be monitored in detail. Based on all of these fiducial marks, The amount of change over time may be obtained to adjust the execution interval of the correction process. However, in this case, each reference mark needs to be imaged by the imaging unit, which is disadvantageous for shortening the tact time. Therefore, when the variation amount regarding the earliest reference mark first picked up by the image pickup unit among the plurality of reference marks is smaller than a predetermined value, the image pickup of the remaining reference marks by the image pickup unit may be omitted. As a result, an increase in tact time can be suppressed.

  In the invention configured as described above, a fluctuation amount is obtained with respect to the temporal change of the position information of the reference mark fixed at a preset position, and the execution interval of the correction process is adjusted according to the fluctuation amount. For this reason, it is possible to perform the correction process at an appropriate execution interval and perform the component mounting work stably, while at the same time eliminating the excessive correction process and reducing the tact time.

It is a top view which shows 1st Embodiment of the component mounting apparatus concerning this invention. It is a partial front view of the component mounting apparatus shown in FIG. It is a block diagram which shows the main electrical structures of the component mounting apparatus shown in FIG. It is a graph which shows the example of a change of the error of a head unit in a component mounting operation. It is a flowchart which shows the content of the correction process in 1st Embodiment. It is a flowchart which shows the content of the space | interval adjustment process in 1st Embodiment. It is a figure which shows an example of the correction process performed by the component mounting apparatus shown in FIG. 1, and the adjustment process of a correction | amendment interval. It is an example of the correction | amendment space | interval in 1st Embodiment. It is a flowchart which shows the content of the correction process performed in 2nd Embodiment of the component mounting apparatus concerning this invention. It is a flowchart which shows the content of the space | interval adjustment process in 2nd Embodiment.

  FIG. 1 is a plan view showing a first embodiment of a component mounting apparatus according to the present invention. FIG. 2 is a partial front view of the component mounting apparatus shown in FIG. FIG. 3 is a block diagram showing the main electrical configuration of the component mounting apparatus shown in FIG. In FIGS. 1 and 2, XYZ rectangular coordinate axes are shown in order to clarify the directional relationship between the drawings.

  In the component mounting apparatus 1, the board transport mechanism 2 is disposed on the base 11, and the board S can be transported in a predetermined transport direction X. More specifically, the substrate transport mechanism 2 has a pair of conveyors 21 and 21 that transport the substrate S from the right side to the left side of FIG. And the conveyors 21 and 21 operate | move according to the operation command from the drive control part 82 of the control unit 8, carry in the board | substrate S, and stop at a predetermined mounting work position (position of the board | substrate S shown in the figure). The substrate S is fixed and held by a holding device (not shown). Then, the electronic component P (see FIG. 2) supplied from the component supply unit 4 is transferred to the substrate S by the mounting head 61 provided in the head unit 6. When all the electronic components P to be mounted on the substrate S have been mounted on the substrate S, the substrate transport mechanism 2 unloads the substrate S. A component recognition camera 7 is disposed on the base 11. The component recognition camera 7 includes an illumination unit, a CCD (Charge Coupled Device) camera, and the like, and images the electronic component P held by the suction nozzle 62 of each mounting head 61 of the head unit 6 from below. It is like that.

  The component supply unit 4 is arranged on the front side (+ Y axis direction side) and the rear side (−Y axis direction side) of the substrate transport mechanism 2 configured as described above. These component supply units 4 include a number of tape feeders 41. Each tape feeder 41 is provided with a reel (not shown) around which a tape storing and holding the electronic component P is wound, so that the electronic component P can be supplied to the head unit 6. That is, each tape stores and holds small chip electronic components P such as an integrated circuit (IC), a transistor, and a capacitor at predetermined intervals. Then, the tape feeder 41 feeds the tape from the reel toward the head unit 6, whereby the electronic component P in the tape is intermittently fed to the component suction position, and as a result, is mounted on the mounting head 61 of the head unit 6. The pickup nozzle 62 can pick up the electronic component P.

  The head unit 6 transports the electronic component P to the substrate S while being sucked and held by the suction nozzle 62 of the mounting head 61 and transfers the electronic component P to the component mounting position designated by the user. Then, a total of twelve mounting heads 61 including six mounting heads 61F arranged in a line in the X-axis direction on the front side and six mounting heads 61R arranged in a line in the X-axis direction on the rear side are arranged. Have. That is, as shown in FIGS. 1 and 2, in the head unit 6, six mounting heads 61F extending in the vertical direction Z are arranged at an equal pitch in the X-axis direction (the direction in which the substrate S is transported by the substrate transport mechanism 2). It is provided in a row. Further, a rear row configured in the same manner as the front row is provided on the rear side (−Y-axis direction side) with respect to the mounting head 61F. That is, six mounting heads 61 </ b> R extending in the vertical direction Z are provided in a row at an equal pitch in the X-axis direction. In the present embodiment, the mounting head 61F and the mounting head 61R are arranged with a half pitch shift in the X-axis direction, and are arranged in a zigzag shape in plan view as shown in FIG. Therefore, when viewed from the Y-axis direction, as shown in FIG. 2, the twelve mounting heads 61 are arranged in a line in the X-axis direction without overlapping each other.

  Further, the suction nozzle 62 mounted at the tip of each mounting head 61 can communicate with any one of a negative pressure generator, a positive pressure generator, and the atmosphere via a pressure switching mechanism (not shown). The pressure applied to the suction nozzle 62 can be switched by the unit 8 controlling the pressure switching mechanism. That is, by applying a negative pressure suction force from the negative pressure generator to the suction nozzle 62 by switching the pressure, the lower end portion (tip portion) of the suction nozzle 62 sucks the upper surface of the electronic component P and can hold the component. It has become. Conversely, when a positive pressure from the positive pressure generator is supplied to the suction nozzle 62, the suction holding of the electronic component P by the mounting head 61 is released, and the electronic component P is instantaneously mounted on the substrate S by the positive pressure. Then, after mounting the electronic components, the suction nozzle 62 is opened to the atmosphere. Thus, in the head unit 6, the electronic component P can be attached and detached by controlling the negative pressure adsorption force and the positive pressure supply by the control unit 8.

  Incidentally, the mounting head 61 is configured to be able to switch the nozzle used for component mounting from among a plurality of types of suction nozzles 62. That is, the auto nozzle changer 5 is provided between the component supply unit 4 on the rear side and the mounting work position in the component mounting apparatus 1, and the suction nozzle 62 attached to the mounting head 61 is switched in the auto nozzle changer 5. (Nozzle change). Thus, the suction nozzle 62 attached to the mounting head 61 is used as a use nozzle in the subsequent component mounting.

  Each mounting head 61 can be moved up and down (moved in the Z-axis direction) with respect to the head unit 6 by a nozzle lifting / lowering drive mechanism (not shown) and rotated about the nozzle center axis by a nozzle rotation driving mechanism (not shown) (FIG. 2). In the R direction). Among these drive mechanisms, the nozzle raising / lowering drive mechanism raises and lowers the mounting head 61 between a lowered position (falling end) when sucking or mounting and a rising position (raising end) when carrying. . On the other hand, the nozzle rotation driving mechanism is a mechanism for rotating the suction nozzle 62 as required, and can position the electronic component P in a predetermined R-axis direction during mounting by rotation driving. These drive mechanisms are each composed of a Z-axis servo motor 72, an R-axis servo motor 73, and a predetermined power transmission mechanism. The drive control unit 82 of the control unit 8 controls the Z-axis servo motor 72 and the R-axis. By controlling the servo motor 73, each mounting head 61 is moved in the Z direction and the R direction.

  Further, since the head unit 6 transports the electronic component P sucked by these mounting heads 61 between the component supply unit 4 and the substrate S and mounts it on the substrate S, the X-axis is extended over a predetermined range of the base 11. It can move in the direction and the Y-axis direction (direction orthogonal to the X-axis and Z-axis directions). That is, the head unit 6 is supported so as to be movable along the X axis with respect to the mounting head support member 63 extending in the X axis direction. Further, both ends of the mounting head support member 63 are supported by a fixed rail 64 in the Y-axis direction, and are movable along the fixed rail 64 in the Y-axis direction. The head unit 6 is driven in the X-axis direction by the X-axis servomotor 65 via the ball screw 66, and the mounting head support member 63 is driven in the Y-axis direction by the Y-axis servomotor 67 via the ball screw 68. Is done. In this way, the head unit 6 can transport the electronic component P attracted by the mounting head 61 from the component supply unit 4 to the target position.

  Furthermore, the head unit 6 includes a component inspection camera 91. The component inspection camera 91 includes an illumination unit and a CCD camera, and is used for inspecting the mounting state of each electronic component mounted on the substrate S. Specifically, the drive control unit 82 moves the head unit 6 as appropriate, thereby moving the component inspection camera 91 above the mounting position of the electronic component P. In this state, the image of the electronic component P captured by the component inspection camera 91 is transferred to the image processing unit 84. The image processing unit 84 determines the quality of the mounted state of the electronic component P from the transferred image of the electronic component P. In the present embodiment, the component inspection camera 91 functions to image reference marks M1 to M6 provided at positions set in advance with respect to each part of the component mounting apparatus 1 and the substrate S in addition to imaging the component. Also has. More specifically, the reference marks M1 to M3 are provided at three intervals on the frame (not shown) of the conveyors 21 and 21 that are not deformed due to thermal expansion with a certain interval therebetween. It arrange | positions so that it may be located in the vertex of a substantially right-angled triangle by planar view. The reference marks M4 and M5 are fiducial marks provided at a predetermined interval at two locations on the surface of the substrate S. Further, the reference mark M6 is provided on the auto nozzle changer 5.

  The component mounting apparatus 1 includes a display 92 that functions as an interface with the worker. In addition to the function of displaying the operation state of the component mounting apparatus 1, the display 92 includes a touch panel and has a function as an input terminal that receives input from an operator. The input / output control for the display 92 is executed by the input / output control unit 88 of the control unit 8.

  The overall operation of the component mounting apparatus 1 configured as described above is controlled centrally by the main control unit 85 of the control unit 8. That is, the main control unit 85 controls the entire apparatus 1 by exchanging signals with each unit of the control unit 8 via the bus 87 based on programs and data stored in the storage unit 86. The program 861 stored in the recording medium 862 such as a CD (compact disk), a DVD (digital versatile disk), or a USB (Universal Serial Bus) memory is stored in the storage unit 86.

  For example, when producing a plurality of mounting boards, the main control unit 85 reads out a production program 861 (production program) stored in the storage unit 86. The main control unit 85 controls each part of the control unit 8 according to the program 861 so that component mounting is sequentially performed on the plurality of boards S that are carried in, and a plurality of mounting boards are produced. .

  Specifically, component mounting is performed in which a predetermined electronic component P is mounted on each mounting position of one substrate S carried in and fixed at the mounting work position. When electronic components P are mounted on all mounting positions on one substrate S (that is, when component mounting is completed), one substrate S is unloaded from the mounting work position and the next substrate S is mounted. It is carried in and fixed at the position (board transfer), and a new component mounting is executed on the next board S. Such an operation is repeatedly executed to produce a plurality of mounting boards.

  Further, the program 861 intermittently executes the correction process in addition to the operation of repeatedly mounting components on the board S to be carried in. This is for the same reason as explained in the section “Background Art”. That is, in the component mounting apparatus 1 shown in FIG. 1, when the component mounting is repeatedly performed without performing the correction process, the head unit is caused by the thermal displacement of each part of the apparatus as the internal temperature of the component mounting apparatus 1 increases with the elapsed time. An error occurs in the movement amount of 6. For example, as shown in FIG. 4, the errors in the X-axis direction and the Y-axis direction change with time. Therefore, in order to accurately mount the component on the board S, it is necessary to correct the movement of the head unit 6 in consideration of the error. In the present embodiment as well, the program 861 is performed while the component mounting is repeated. Accordingly, the main control unit 85 performs the correction process intermittently. In this correction processing, the operation of acquiring and storing the position information of the reference mark based on the mark image obtained by imaging the reference mark with the component inspection camera 91 is performed for all or a part of the reference marks M1 to M6. Later, a plurality of pieces of position information are read out, and an error is calculated therefrom to correct the movement of the head unit 6, thereby correcting the movement amount error caused by the thermal displacement. Since the processing content itself is well known, the description of the content of the correction processing is omitted in this specification.

  As is apparent from FIG. 4, the error saturates with time in both the X-axis direction and the Y-axis direction. That is, the thermal displacement is relatively large immediately after the start of component mounting and in the initial stage. On the other hand, the thermal displacement becomes smaller as the repetition time of component mounting becomes longer. Considering such thermal displacement characteristics, it is desirable to adjust the execution interval of the correction process according to the characteristics, and the main control unit 85 controls each part of the apparatus as described below to execute the interval adjustment. . As described above, in this embodiment, the main control unit 85 functions as the mounting processing unit 851 that executes the mounting process, the correction processing unit 852 that executes the correction process, and the interval adjustment unit 853 that adjusts the execution interval of the correction process.

  FIG. 5 is a flowchart showing the content of the correction process in the first embodiment. FIG. 6 is a flowchart showing the contents of the interval adjustment process in the first embodiment. Hereinafter, after the execution of the correction process in the component mounting apparatus of FIG. 1 will be described with reference to FIGS. 5 and 6, an example of the execution interval of the correction process (hereinafter referred to as “correction interval”) will be described.

  In the component mounting apparatus 1, when component mounting is started, the main control unit 85 resets a count value N indicating the number of executions of correction processing to zero (step S1) and a relatively short initial interval ΔT1 (for example, 1 minute) ) (Step S2). Further, immediately after the start of component mounting, as shown in FIG. 4, the error fluctuates relatively greatly in both the X-axis direction and the Y-axis direction, so that the predetermined count value Nx ( For example, 3 times). That is, the main control unit 85 increments the count value N by “1” (step S3), waits for the correction interval to elapse (step S4), and executes the correction process (step S5). The main controller 85 repeats such processing (steps S3 to S5) while the count value N is less than the predetermined count value Nx (step S6). For example, when the predetermined count value Nx is set to “3” as described above, the first three correction processes are always executed intermittently with a short correction interval ΔT1. Note that the reference mark position information obtained during the three correction processes is sequentially stored in the storage unit 86 and used for adjustment of the correction interval (step S7) as described below.

  On the other hand, when it is determined in step S6 that the count value N is equal to or greater than the predetermined count value Nx, that is, a predetermined time or more has elapsed since the start of component mounting, the main control unit 85 adjusts the correction interval (step S7). Here, at least the position information of the first reference mark M1 is stored in the correction process (step S5), and the correction interval is adjusted based on the position information as described with reference to FIG. 6, except for the first reference mark M1. It is also possible to use the position information of the reference marks M2 to M6, or to adjust the correction interval based on the position information of a plurality of reference marks.

In the adjustment of the correction interval (step S7), as shown in FIG. 6, the main control unit 85 reads the position information of the latest Nx times from the position information of the first reference mark M1 stored in the storage unit 86, A moving average (Xave, Yave) of the first reference mark M1 is obtained (step S71). For example, when the current count value N is “4” and the predetermined count value Nx is “3”, the position information Xcur1 (1) in the X-axis direction of the first reference mark M1 acquired in the first correction process. Position information Ycur1 (1) in the Y axis direction, position information Xcur1 (2) in the X axis direction of the first reference mark M1 acquired in the second correction process, and position information Ycur1 (2) in the Y axis direction, Based on the position information Xcur1 (3) in the X-axis direction and the position information Ycur1 (3) in the Y-axis direction of the first reference mark M1 acquired in the third correction process,
Xave = Xave (1-3) = (Xcur1 (1) + Xcur1 (2) + Xcur1 (3)) / 3
Yave = Yave (1-3) = (Ycur1 (1) + Ycur1 (2) + Ycur1 (3)) / 3
The moving average (Xave, Yave) is calculated according to

At the same time as or before or after the calculation of the moving average (step S71), the main controller 85 moves the head unit 6 toward the first reference mark M1, and images the first reference mark M1 by the component inspection camera 91 ( Step S72). Then, the main control unit 85 acquires the current position information (Xcur, Ycur) of the first reference mark M1 based on the captured mark image (step S73), and then the first control in the X-axis direction and the Y-axis direction. The error ΔX, ΔY of the reference mark M1 is expressed by the following equation: ΔX = | Xcur−Xave |
ΔY = | Ycur−Yave |
(Step S74). Further, the main control unit 85 obtains the maximum error Max (ΔX, ΔY) of the first reference mark M1, and adjusts the correction interval according to the value (steps S75 to S79). More specifically, as shown in FIG. 6, when the maximum error Max (ΔX, ΔY) is not less than a relatively large value D1 (eg, 5 μm) (“YES” in step S75), the correction interval is set to the initial value. The interval ΔT1 is set (step S76). If the maximum error Max (ΔX, ΔY) is smaller than the value D1, but exceeds the error tolerance D2 (eg, 3 μm) (“YES” in step S77), the correction interval is set to be greater than the initial interval ΔT1. A long interval ΔT2 (for example, 5 minutes) is set (step S78). Further, when the maximum error Max (ΔX, ΔY) is equal to or smaller than the allowable error value D2 (“NO” in step S77), the correction interval is set to a longer interval ΔT3 (for example, 30 minutes) (step S79). ).

  When the adjustment of the correction interval is completed in this way, as shown in FIG. 5, the process returns to step S3 to execute the next correction process.

  As described above, in the present embodiment, since the correction process (step S5) is intermittently performed while the components are being mounted, the head unit 6 can always be moved to an appropriate position. The component mounting operation can be executed with high accuracy and stability.

  Further, the position information (Xcur, Ycur) of the first reference mark M1 is obtained over time, and the maximum error (corresponding to “a variation amount of position information with time” of the present invention) is obtained. Then, the correction interval (correction processing execution interval) is adjusted according to the maximum error, and the correction processing according to the thermal displacement characteristics is performed as described above. Thus, the execution interval of the correction process can be optimized, and the tact time can be shortened by eliminating the excessive correction process.

  Further, since the extension of the correction interval is set in two steps according to the magnitude of the maximum error, the correction interval is extended in multiple steps as the maximum error becomes smaller, that is, as the thermal displacement becomes smaller. As described above, since the execution interval of the correction process is adjusted correspondingly to the thermal displacement characteristic, the tact time can be further effectively shortened.

FIG. 7 is a diagram illustrating an example of correction processing and correction interval adjustment processing executed in the component mounting apparatus shown in FIG. FIG. 8 is an example of a correction interval in the first embodiment. In addition, the vertical direction of FIG. 7 has shown time passage. In this specific example, the predetermined count value Nx is set to “3”, and the intervals ΔT1, ΔT2, and ΔT3 are ΔT1 <ΔT2 <ΔT3.
Is set to The correction process is executed based on the reference marks M1 to M3. Further, the values D1 and D2 are set to “5 μm” and “3 μm”, respectively.

  In this specific example, when the time ΔT1 elapses as the correction interval from the start of component mounting, the position information ((Xcur1 (1), Ycur1 (1)), (Xcur2 (1), Ycur2 (1)) of the reference marks M1 to M3. ), (Xcur3 (1), Ycur3 (1))) are acquired, and based on these, a correction calculation is executed, and the movement of the head unit 6 is corrected. Thereafter, as in the first time, correction processing is executed after the correction interval ΔT1 has elapsed.

  When the third correction process is completed, the correction interval is adjusted each time the correction process is executed. The error ΔX in the X-axis direction at this point is about “0 μm” as shown in FIG. 8, but the error ΔY in the Y-axis direction is about “11 μm”, and the correction interval is maintained at the interval ΔT1. Has been. Then, when the time ΔT1 has elapsed as the correction interval from the third correction process, the position information ((Xcur1 (4), Ycur1 (4)), (Xcur2 (4), Ycur2 (4)) of the reference marks M1 to M3), (Xcur3 (4), Ycur3 (4))) is acquired, and based on these, a correction calculation is performed, and the movement of the head unit 6 is corrected (fourth correction process).

  When the fourth correction process is completed, the correction interval is adjusted again. Then, the correction interval adjustment process is executed in the same manner as described above. Here, since the errors ΔX and ΔY are both within the values D1 and D2, the correction interval is changed from the interval ΔT1 to the interval ΔT2. Can be spread. Accordingly, the next sixth correction process is executed after waiting for a longer interval ΔT2 than before. After that, every time the correction process is completed, a correction interval adjustment process is performed, and as shown in FIG. 8, the correction interval is often increased with the lapse of time from the start of component mounting. The number of times can be reduced and the tact time can be greatly reduced.

  FIG. 9 is a flowchart showing the contents of the correction processing executed in the second embodiment of the component mounting apparatus according to the present invention. FIG. 10 is a flowchart showing the contents of the interval adjustment process in the second embodiment. The second embodiment is greatly different from the first embodiment in the following points. That is, in the first embodiment, the correction process is performed without adjusting the correction interval for the first Nx times, but after that, the correction interval is adjusted (= moving average income of the reference mark M1 + reference mark M1). The correction processing is executed after the acquisition of the position information by the imaging of the above and the determination of the correction interval. On the other hand, in the second embodiment, as shown in FIG. 9, it is determined whether the number of correction processes (count value N) exceeds a predetermined number Nx after the correction process (step S5) (step S5). S8) As long as N does not exceed, the process returns to step S3 and correction processing is performed. That is, the correction process is performed without adjusting the correction interval for the first (Nx + 1) times.

  In addition, when “YES” is determined in Step S8, that is, when the (Nx + 1) th and subsequent correction processes are completed, the correction interval shown in FIG. 10 is adjusted (Step S9). That is, the main control unit 85 performs the latest correction process (Nth correction process) at the same time as or after the moving average of the first reference mark M1 (step S91) in the same manner as in the first embodiment. The position information of the obtained first reference mark M1 is read from the storage unit 86 (step S92). Thereafter, as in the first embodiment, the main control unit 85 calculates the errors ΔX and ΔY (step S93) and obtains the maximum error Max (ΔX, ΔY) of the first reference mark M1 (step S94). ), The correction interval is adjusted according to the value (steps S94 to S98).

  As described above, in the second embodiment, as in the first embodiment, the correction process (step S75) is intermittently performed while the components are being mounted, and the maximum error of the first reference mark M1 is performed. Since the correction interval (correction processing execution interval) is adjusted according to the above, the same effect as the first embodiment can be obtained. Furthermore, since the maximum error of the first reference mark M1 is obtained by using the position information of the first reference mark M1 obtained in the correction process executed immediately before the adjustment of the correction interval as it is, the first reference mark M1 is obtained. Imaging operation (step S72) is not required, and the tact time can be further shortened.

  As described above, in the above-described embodiment, the X-axis servo motor 65 and the Y-axis servo motor 67 correspond to an example of the “head drive mechanism” of the present invention. The component inspection camera 91 corresponds to an example of the “imaging unit” of the present invention. The main control unit 85 corresponds to an example of “correction processing unit”, “interval adjustment unit”, and “computer” of the present invention, and the program 861 corresponds to “control program for component mounting apparatus” of the present invention. Yes. The first reference mark M1 corresponds to an example of the “reference mark” in the present invention.

  The present invention is not limited to the above-described embodiment, and various modifications can be made to the above-described one without departing from the spirit of the present invention. For example, in the above embodiment, the correction interval is adjusted while the component mounting operation is repeated. However, when the component execution operation is stopped, the correction interval is appropriately increased as described below. Is desirable. This is because when the component mounting operation is stopped, the internal temperature of the component mounting apparatus 1 decreases with time. Even if the inside of the component mounting apparatus 1 is in a warm state (a state where the thermal displacement is saturated or almost saturated) at the time of the stop, if the stop time becomes long, the cold state (the thermal displacement becomes unsaturated). Shift to the state). Therefore, the main control unit 85 measures the stop time during which the mounting of the components is stopped, and if it exceeds a certain value, it is determined that it has shifted to the cold state, and the correction interval is narrowed, for example, returned to the initial interval ΔT1. It may be configured. Thereby, the correction process immediately after restarting the mounting of components can be executed at intervals corresponding to the cold state, and the component mounting work can be performed with high accuracy even immediately after the restart. In this embodiment, the main control unit 85 functions as the “stop time measuring unit” of the present invention.

  In the above embodiment, the maximum error (corresponding to the “variation amount” of the present invention) is obtained based on the first reference mark M1, but the maximum error may be obtained based on the other reference marks M2 to M6. Good. In addition, the maximum error may be obtained by using the position information of a plurality of reference marks, the thermal displacement in each part in the component mounting apparatus 1 can be monitored in detail, and the adjustment accuracy of the correction interval can be improved. Can do. However, on the other hand, each reference mark needs to be imaged by the component inspection camera 91, which is disadvantageous for shortening the tact time. Therefore, when the error (variation amount) regarding the earliest reference mark first captured by the component inspection camera 91 among the plurality of reference marks is smaller than a predetermined value, the remaining reference marks are not captured by the component inspection camera 91. May be.

  In the above embodiment, the component inspection camera 91 is also used for imaging the reference marks M1 to M6. However, a dedicated imaging unit that images the reference marks M1 to M6 may be provided.

  In the above embodiment, the correction interval spread according to the magnitude of the maximum error is set to two stages, but may be set to one stage, or conversely, may be set to three or more stages.

  The present invention can be applied to all component mounting techniques for mounting components on a substrate using a head unit.

DESCRIPTION OF SYMBOLS 1 ... Component mounting apparatus 6 ... Head unit 8 ... Control unit 65 ... X-axis servomotor (head drive mechanism)
67 ... Y-axis servo motor (head drive mechanism)
85 ... Main control unit (correction processing unit, interval adjustment unit, stop time measurement unit, computer)
91 ... Parts inspection camera (imaging part)
852 ... Correction processing unit 853 ... Interval adjustment unit 861 ... Program 862 ... Recording medium M1-M6 ... Reference mark P ... Electronic component S ... Substrate Xcur1-Xcur3, Ycur1-Ycur3 ... Position information

Claims (8)

A head unit for mounting components on the board;
A head driving mechanism for driving the head unit;
An imaging unit for imaging a reference mark fixed at a preset position;
A control unit for controlling the head driving mechanism to control the mounting of the component on the substrate by the head unit, and
The control unit is
While the component is being mounted, a correction process for correcting the movement of the head unit by the head driving mechanism is intermittently executed based on the change over time of the position information of the reference mark imaged by the imaging unit. A correction processing unit to
An interval adjustment unit that adjusts an execution interval of the correction process according to a variation amount of the temporal change;
A component mounting apparatus comprising: The component mounting apparatus according to claim 1,
The interval adjusting unit is a component mounting apparatus that expands the execution interval as the variation amount decreases. The component mounting apparatus according to claim 2,
The said space | interval adjustment part is a component mounting apparatus which extends the said execution space | interval in multiple steps according to the said variation | change_quantity. The component mounting apparatus according to claim 2 or 3,
The control unit has a stop time measuring unit that measures a stop time during which the mounting of the component is stopped,
The interval adjusting unit is a component mounting apparatus that narrows the execution interval when the stop time measured by the stop time measuring unit exceeds a certain value. The component mounting apparatus according to any one of claims 1 to 4,
A plurality of the reference marks are provided at different positions,
The control unit omits imaging of the remaining reference marks by the imaging unit when the variation amount related to the earliest reference mark first captured by the imaging unit among the plurality of reference marks is smaller than a predetermined value. Component mounting equipment. A component mounting method for moving a head unit and mounting a component on a substrate by the head unit,
While the mounting of the component is repeatedly performed, a change with time of the position information of the reference mark is obtained from an image of the reference mark obtained by imaging a reference mark fixed at a preset position. A step of intermittently performing a correction process for correcting the movement of the head unit based on a change;
Adjusting the execution interval of the correction process according to the variation amount of the change over time;
A component mounting method characterized by comprising: A program for controlling a component mounting apparatus that moves a head unit and mounts a component on a board by the head unit,
While the mounting of the component is repeatedly performed, a change with time of the position information of the reference mark is obtained from an image of the reference mark obtained by imaging a reference mark fixed at a preset position. A correction function that intermittently executes correction processing for correcting movement of the head unit based on a change;
A program for controlling a component mounting apparatus, which causes a computer to realize an interval adjustment function for adjusting an execution interval of the correction processing in accordance with a variation amount of the temporal change.   8. A recording medium on which the control program for the component mounting apparatus according to claim 7 is recorded.

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