JP2001251098A - Component mounting position correcting method and surface mounter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely mount a component on a board by accurately and reasonably correcting the mounting position of the component with a head unit. SOLUTION: With a mark provided to a head unit, a component recognizing camera 23 comprising a CCD linear sensor is provided on a stage, and after the component is sucked, the head unit 5 is moved to the camera 23 to image the sucked component and the mark 22. The sucking deviation amount for the component is acquired by a calculation means 34 based on a positional relation ship between the mark 22 and a sucking head 20 which is a know information and a positional relationship between mark 22 and the sucked component is on a screen. At mounting, the driving of heat unit 5 is controlled by a main control means 31 based on the deviation amount.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for correcting a mounting position of a surface mounter configured to mount a component such as an IC on a printed circuit board, and a surface mounter capable of performing the correction method.

[0002]

2. Description of the Related Art Conventionally, an electronic component such as an IC is sucked from a component supply unit by a movable head unit having a suction head for picking up a component, and this component is placed on a printed circuit board positioned at a predetermined work position. A surface mounter adapted to be transported to and mounted on a device is generally known.

[0003] In this type of mounting machine, it is necessary to mount components on a printed circuit board taking into account the deviation of suction of components from the suction head. That is, it is necessary to correct the movement target position at the time of mounting the head unit according to the suction state of the components.

In this method, for example, a mark is provided near a suction head of a head unit, the positional relationship between the mark and the suction head is checked in advance and stored as known information, and a camera comprising a CCD area sensor is mounted on a base. After the component is sucked, the mark and the sucked component are imaged by a camera, and the shift amount of the component with respect to the suction head is obtained based on the positional relationship between the mark on the image and the sucked component and the known positional relationship. It is conceivable to correct the mounting position based on the amount.

[0005]

In the above-described method, since it is necessary to capture an image of the mark and the suction component by a camera including a CCD area sensor, for example, in a mounting machine having a plurality of suction heads in a head unit, It is necessary to provide a mark for each suction head.

However, the head unit tends to be miniaturized in order to increase the mounting speed, and there is a problem that it is difficult to provide a mark for each suction head in terms of space. Therefore, it is desired to be able to accurately detect a component suction deviation while responding to a demand for miniaturization of a head unit.

In this type of mounting machine, a driving error,
It is known that a movement error occurs in the head unit due to a thermal expansion of a mechanism portion and the like, which affects mounting accuracy. Therefore, it is necessary to examine such a movement error of the head unit at the time of imaging the suction component. If possible, the mounting position of the component can be corrected more accurately, which is convenient.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. A first object is to rationally correct a component mounting position by a head unit, and a second object is to provide a substrate. In order to be able to mount components with higher accuracy for

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention suctions an electronic component from a component supply unit by a movable head unit having a suction head for mounting a component, and removes the component from a predetermined position. This is a method of correcting a mounting position when mounting on a substrate positioned at a work position of the head, by moving a head unit after passing a component, and passing the head unit over a linear sensor provided on a base. The mark provided on the unit and the suction component are imaged by the linear sensor, and the positional relationship between the mark and the suction component on the image is obtained. The pickup state of the component is checked based on the detected state, and the mounting position of the component by the head unit is corrected based on the pickup state.

According to this method, the suction component and the mark are continuously imaged as one image while moving the head unit with respect to the linear sensor. Therefore, even if the head unit has a plurality of suction heads, only one mark is required. The mounting position can be corrected by checking the suction state of each component.

In the method of correcting a component mounting position according to the first aspect of the present invention, a pair of marks provided on the head unit are picked up by the linear sensor as the marks, and the distance between the two marks on the image and the distance between the marks are determined. It is preferable that a movement error of the head unit is obtained based on the reference value, and that the mounting position of the component by the head unit is corrected in consideration of the error.

With this configuration, it is possible to further take into account the movement error of the head unit due to the drive error, the thermal expansion of the mechanism, and the like, and the reliability of the mounting position correction is improved.

On the other hand, the surface mounter according to the present invention sucks an electronic component from the component supply unit by a movable head unit having a suction head for mounting a component, and positions the component at a predetermined work position. A mark provided on the head unit in a surface mounter mounted on the
A linear sensor arranged on a base and capable of imaging a mark and a suction component, and executes a predetermined mounting operation,
After picking up the component in the mounting operation, the head unit is moved with respect to the linear sensor, and control means for controlling the drive of the head unit to execute a component recognition operation of picking up the picked-up component and the mark is performed. Calculating means for calculating a positional shift of the component based on the positional relationship between the mark and the suction component on the image and the positional relationship between the mark and the suction head, which is known information stored in advance, and The mounting position of the component by the head unit is corrected on the basis of the suction deviation amount obtained by the calculating means (claim 3).

According to this apparatus, after the component is sucked, the head unit moves above the linear sensor to capture an image of the mark and the sucked component. Based on the image, the shift amount of the sucked component is determined. The mounting position of the component is corrected by controlling the driving of the head unit on the basis of the suction deviation amount.

In this device, as the mark,
A pair of marks that are continuously imaged in the moving direction of the head unit during the component recognition operation are provided, and the calculating means further calculates an error between the interval between the two marks on the image and a reference value of the interval. Further, the control means is configured to correct the mounting position of the component by the head unit based on the attraction deviation amount obtained by the calculation means and the error (claim 4).

According to this device, the mounting position of the head unit is corrected based on a movement error of the head unit caused by a driving error, a thermal expansion of the mechanism, and the like.

When a plurality of suction heads are provided in a row as suction heads, marks are arranged in the arrangement direction of the suction heads, and during the component recognition operation, the marks are arranged in the arrangement direction of the suction heads with respect to the linear sensor. It is desirable that the control means be configured to move the head unit (claim 5).

According to this configuration, each suction component and each mark are imaged at a time by moving the head unit in one direction with respect to the linear sensor.

[0019]

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

FIGS. 1 and 2 schematically show an example of a surface mounter (hereinafter abbreviated as a mounter) according to the present invention.
In this figure, a conveyor 2 constituting a transfer line is arranged on a base 1 so that the printed circuit board 3 is transferred on the conveyor 2 and stopped in a state where it is positioned at a predetermined work position. Has become.

At the side of the conveyor 2, a component supply unit 4
Is arranged. The component supply unit 4 includes, for example, a plurality of rows of tape feeders 4a. Each of the tape feeders 4a stores and holds small pieces of electronic components such as ICs, transistors, and capacitors at predetermined intervals. The tape feed end is provided with a feed mechanism, and the tape is intermittently fed as components are picked up by a head unit 5 described later.

Above the base 1, a head unit 5 for mounting electronic components is provided. The head unit 5 is movable across the component supply unit 4 and the printed circuit board 3 positioned at the work position,
In this embodiment, the X-axis direction (the direction of the conveyor 2) and the Y-axis direction
It can be moved in the axial direction (the direction orthogonal to the X axis on the horizontal plane).

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

The Y-axis servo motor 9 and the X-axis servo motor 15 are provided with position detecting means 10 and 16 each comprising an encoder so that the operating position of the head unit 5 can be detected. Has become.

The head unit 5 is provided with a plurality of suction heads 20 each having a nozzle for picking up a component at its tip. In this embodiment, eight suction heads 20 are arranged in a line in the X-axis direction. It is arranged.

Each suction head 20 is capable of moving in the Z-axis direction (vertical direction) and rotating around the R-axis (nozzle center axis) with respect to the frame of the head unit 5, respectively. And an R-axis servomotor. The nozzle of each suction head 20 is connected to negative pressure supply means via a valve or the like, so that a negative pressure for component suction is supplied.

The head unit 5 includes a suction head 2.
A pair of marks 22 for examining a component slippage due to zero is provided. These marks 22 are provided on both sides of the suction heads 20 arranged in the X-axis direction as described above (on both left and right sides in FIG. 2), and are arranged in a line on the suction heads 20. Camera 23
It is provided downward so as to enable imaging by.

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

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

The mounting machine comprises a well-known CPU for executing a logical operation, a ROM for previously storing various programs for controlling the CPU, and a RAM for temporarily storing various data during operation of the apparatus. Control device 30
have.

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

The main control means 31 controls the operation of the mounting machine in a comprehensive manner. The main control means 31 drives the head unit 5 and the like via the driver 32 in order to execute the suction mounting operation of the components in accordance with a program stored in advance. To control. In particular, after the components are sucked, the head unit 5 is driven and controlled to execute a component recognition operation of capturing the components sucked by the suction heads 20 and the marks 22 by the component recognition camera 23, as described in detail later. The drive of the head unit 5 is controlled so as to correct the mounting position of the component by the head unit 5 based on the component shift amount or the like obtained by the component recognition operation.

The driver 32 controls the driving of the head unit 5, and the servomotors 15, 9 for the X axis, Y axis, etc., and their position detecting means 16, 10 are connected to the driver 32. I have. Then, during the mounting operation, the driving of the servo motor 15 and the like is controlled by the main control means 31 via the driver 32 as a whole.

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

The arithmetic means 34 is adapted to operate the mark 22 picked up by the board recognizing camera 23 in the component recognizing operation.
The positional relationship between the (one mark 22) and each suction component on the image, and the positional relationship between the previously stored mark 22 (the one mark 22) and each suction head 20 (theoretical positional relationship, or the Position relationship actually measured; known information)
, The suction deviation amount Δa of each suction component with respect to each suction head 20 is calculated based on the distance between the two marks 22 on the image (that is, the distance in the X-axis direction) and the reference value of the same distance stored in advance. (Theoretical value or a value actually measured in advance) to determine the movement error Δb of the head unit 5 in the X-axis direction.

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

When the mounting operation is started in the mounting machine, first, the printed circuit board 3 is carried in along the conveyor 2 and positioned at the work position, and at the same time, the head unit 5 is mounted. The first component placed above the supply unit 4 is sucked and taken out from the tape feeder 4a (Steps S1 and S2).

Next, it is determined whether or not there is another component to be picked up. If there is, the process shifts to step S1 to pick up the next component (step S3). On the other hand, if there is no other component to be picked up (N in step S3)
O), the process proceeds to step S4, and a component recognition operation is performed.

More specifically, when the head unit 5 moves at a constant speed above the component recognition camera 23, for example, in a direction indicated by an arrow in FIG. Parts and each mark 22
Are sequentially captured in the sub-scanning direction (X-axis direction) and output to the image processing means 33 as a predetermined image signal. Thereby, each suction component and both marks 22 are continuously imaged as one image. At this time, imaging by the component recognition camera 23 is performed in synchronization with a pulse signal output from the position detection means 16 of the X-axis servo motor 15.

In this way, when the head unit 5 has completely passed over the component recognition camera 23 and imaging of all the suction components and both marks 22 is completed, each suction component and the mark 2
2 and the positional relationship between the mark 22 and the known positional relationship between the mark 22 and each of the suction heads 20, the amount of deviation Δa of suction of the component with respect to each of the suction heads 20 is obtained. The movement error Δb of the head unit 5 in the X-axis direction is obtained from the reference value (step S5).

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

When the component is mounted, it is next determined whether or not there is another component to be mounted. If there is, the process proceeds to step S6 to mount the next component. On the other hand, when there is no other component to be mounted (N in step S8)
In O), this flowchart ends.

According to the mounting machine described above, the CCD
Since the suction component of each suction head 20 and both marks 22 are continuously imaged as one image while moving the head unit 5 with respect to the component recognition camera 23 composed of a linear sensor, However, as described above, the suction deviation amount Δa of each component can be obtained based on one mark 22. Therefore, the correction of the mounting position of the component can be obtained with a rational configuration, and thus, there is an effect that it is possible to satisfactorily meet the demand for downsizing the head unit.

Further, a pair of marks 22 are provided on the head unit 5 and these marks 22 are used in the component recognition operation.
The movement error Δb of the head unit 5 in the X-axis direction is obtained by additionally checking the intervals on the image of
Since the mounting position of the component by the head unit 5 is corrected based not only on the component deviation Δa but also on the movement error Δb, it is possible to more accurately mount the component on the printed circuit board 3. There is.

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

[0046]

As described above, according to the present invention,
While moving the head unit with respect to the linear sensor, the mark provided on the head unit and the suction component are continuously imaged as one image to check the suction status of the component. Even when a head is provided, it is possible to satisfactorily correct the mounting position of each suction component only by providing one mark, and it is not necessary to provide a mark for each suction head. Therefore, there is an effect that the mounting position of the component by the head unit can be corrected rationally.

Further, a pair of marks is provided on the head unit as the above-mentioned marks, these are picked up by a linear sensor, and the distance between the two marks on the image is checked to determine the movement error of the head unit. If the mounting position of the component by the head unit is corrected on the basis of the above, the mounting position can be corrected more accurately, and the mounting accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a surface mounter according to the present invention.

FIG. 2 is a front view showing the surface mounter.

FIG. 3 is a block diagram showing a control system of the surface mounter.

FIG. 4 is a flowchart illustrating a mounting operation.

[Explanation of symbols]

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

Claims (5)

[Claims] An electronic component is sucked from a component supply unit by a movable head unit having a component mounting suction head, and the component is mounted on a board positioned at a predetermined work position. This is a position correction method, wherein after a component is sucked, a mark and a suction component provided on the head unit are imaged by the linear sensor by passing the head unit over a linear sensor provided on a base while moving the head unit. At the same time, the positional relationship between the mark and the suction component on the image is obtained, and the suction state of the component is checked based on the positional relationship and the positional relationship between the mark and the suction head, which is known information. A component mounting position correction method, wherein the component mounting position of the head unit is corrected based on the above. 2. The component mounting position correcting method according to claim 1, wherein a pair of marks provided on the head unit are imaged by the linear sensor as the marks, and a distance between the marks on the image and a reference of the distance. A component mounting position correction method, wherein a movement error of the head unit is determined based on the value, and the error is further taken into account to correct the mounting position of the component by the head unit. 3. A surface mounter for picking up an electronic component from a component supply unit by a movable head unit having a component mounting suction head and mounting the component on a board positioned at a predetermined work position. A mark provided on the head unit, a linear sensor disposed on a base, capable of imaging the mark and the suction component, and performing a predetermined mounting operation, and after mounting the component in the mounting operation, Control means for controlling the drive of the head unit so as to execute a component recognition operation of imaging the suction component and the mark while moving the head unit with respect to the linear sensor; and an image of the mark and the suction component captured by the linear sensor Based on the above positional relationship and the positional relationship between the mark and the suction head, which is known information stored in advance. Calculating means for calculating an amount of suction deviation of an article, wherein the control means is configured to correct a mounting position of a component by the head unit based on the amount of suction deviation obtained by the calculating means. Characterized surface mounting machine. 4. The surface mounter according to claim 3, wherein a pair of marks which are continuously imaged in a moving direction of the head unit at the time of the component recognition operation are provided as the marks, and wherein the arithmetic means is provided on the image. Further calculating the error between the interval between the two marks and the reference value of the interval, the control means,
A surface mounter configured to correct a mounting position of a component by a head unit based on the amount of suction deviation and the error obtained by the arithmetic means. 5. The surface mounter according to claim 4, wherein a plurality of suction heads are provided in a row as the suction heads, and the marks are provided in a direction in which the suction heads are arranged. A surface mounter, wherein a head unit is moved in a direction of arrangement of each suction head with respect to the linear sensor during a recognition operation.