JP2003008295A - Method for mounting electronic component and electronic component mounter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for mounting an electronic component and an electronic component mounter, provided with means for checking the mounting state of an electronic component mounted on a circuit board. SOLUTION: Image at the position of a circuit board 5 mounting an electronic component is imaged by an imaging apparatus 7, prior to and after the mounting of the electronic component. A processor 8 takes in the images photographed, before and after the mounting the electronic component and extracts the difference image. Since the image only of the electronic component can be obtained from the difference image, variation from a specified mounting state can be detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting method and apparatus capable of quickly determining the quality of a mounted state of an electronic component mounted on a circuit board.

[0002]

2. Description of the Related Art A suction nozzle that sucks an electronic component from a component supply position is moved to a component mounting position on a circuit board, and the operation of mounting the electronic component on the circuit board by the suction nozzle is repeated to make a plurality of circuit boards on the circuit board. Electronic parts can be mounted. The mounting density of the circuit board is increasing with the miniaturization and high functionality of the equipment using this circuit board, and it is desired to improve the mounting accuracy of electronic components.

FIG. 7 shows a main structure of a rotary head type electronic component mounting apparatus. A rotary head 3 is mounted with a plurality of suction nozzles 2 on its circumference, rotates intermittently, and moves to a component mounting position. The suction nozzle 2 sucks and holds the electronic component 1 from the component supply unit, and when the suction nozzle 2 moves to the component mounting position, the electronic component is placed on the circuit board 5 whose predetermined position is positioned at the component mounting position by the XY table 6. Wear 1. At a predetermined stop position where the suction nozzle 2 moves from the component supply position to the component mounting position, a component recognition device 48 for detecting the holding posture and the holding position of the electronic component 1 suction-held by the suction nozzle 2 is arranged. The deviation of the electronic component 1 from the predetermined position / orientation detected in step 1 is corrected by the movement operation of the XY table 6 and the rotation operation of the suction nozzle 2, so that the electronic component 1 is mounted at the correct position on the circuit board 5. It

However, it is difficult to guarantee the quality of the circuit board to be produced, because the circuit board 5 is not provided with means for determining whether or not the electronic component 1 is normally mounted. Therefore, the quality of the circuit board production can be improved by providing a means for determining the quality of the mounted state of the electronic component on the circuit board. As a means for judging the quality of the mounted state, as shown in FIG.
The one disclosed in Japanese Patent Publication No. 097 is known.

In FIG. 9, the suction nozzle 23 sucks the electronic component 21 from the component supply position and moves it to the component mounting position S set on the vertical line shown. The circuit board 22 on which the electronic component 21 is mounted is fixed on the XY table 24,
The XY table 24 positions the predetermined position of the circuit board 22 at the component mounting position S, so that the suction nozzle 23 that has moved to the component mounting position S moves down to place the sucked electronic component 21 at the predetermined position of the circuit substrate 22. be able to. The suction nozzle 23 having the electronic component 21 placed on the circuit board 22 releases the electronic component 21 by releasing the suction, and the electronic component 21 is mounted at a predetermined position on the circuit substrate 22 by moving upward.

In order to detect the mounting state of the electronic component 21 mounted on the circuit board 22 by the above operation, the camera 25 and the illumination 26 are directed toward the component mounting position S on the circuit board 22.
And are provided. The image captured by the camera 25 is displayed on the monitor device 28 and the controller 2
The mounting state of the electronic component 21 on the circuit board 22 is determined by the image processing by 7.

[0007]

The mounting speed of electronic parts has been remarkably improved by the electronic part mounting apparatus, and high-speed processing is also required to judge the quality of the mounting state. Also, there is a problem that it takes time to perform image processing and the speed of the mounting state inspection cannot keep up with the mounting speed. At the present time, the electronic component mounting speed of the electronic component mounting device is a high-speed operation in which one electronic component is mounted in 0.065 seconds. On the other hand, the processing time in the above configuration requires 0.1 seconds or more, and the inspection speed of the mounted state cannot keep up.

Further, the surface color and surface roughness of electronic parts differ greatly depending on the product type. When the surface color of the circuit board and the color tone of the electronic parts are in the same system, the electronic parts are not sufficiently recognized and erroneous detection is performed. May occur.

Further, the reliability of software for performing image processing is about 99.99%, but the reliability of mounting electronic parts is required to be 99.999% or higher. Inferior condition makes it impossible to secure sufficient inspection capability.

It is an object of the present invention to provide an electronic component mounting method and apparatus capable of detecting the mounting state of electronic components mounted on a circuit board at high speed and with high reliability.

[0011]

A first invention of the present application for achieving the above object comprises a suction nozzle that suction holds an electronic component from a component supply position, and a predetermined position of a circuit board on which the electronic component is mounted. An electronic component mounting method of positioning an electronic component on a circuit board by a lowering operation of a suction nozzle, mounting an electronic component on a circuit board by a suction releasing and raising operation of the suction nozzle, and mounting the electronic component at a predetermined position on the circuit board. ,
It is characterized in that a predetermined position of the circuit board is imaged by the image pickup device before and after mounting the electronic component, and whether the mounting state of the electronic component is good or bad is determined from the difference image between the image before mounting and the image after mounting. .

According to the above-described electronic component mounting method, the difference image is obtained by performing image processing on the pre-mounting image and the post-mounting image before and after mounting the electronic component on the predetermined position of the circuit board.
Only the electronic components mounted on the circuit board can be extracted, and the mounting state of the electronic components can be detected. In addition, since the data processing is simple, the occurrence of software errors is extremely small, and highly reliable detection can be performed. By detecting the mounting state, it is possible to determine whether or not the electronic component has been mounted normally, and it is possible to improve the reliability of circuit board production.

In the above electronic component mounting method, by adjusting the depth of focus of the image pickup means on the basis of the size, mounting position, and angle data of the electronic component to be mounted, the definition of the image picked up by the image pickup means is improved. It becomes possible to accurately detect the mounted state.

Further, by adjusting the processing area of the difference image based on the data of the size, mounting position, and angle of the electronic component, the image processing can be performed only on the required area, and the processing speed is improved. It becomes possible to cope with high-speed mounting of electronic components.

According to the second aspect of the present invention, the suction nozzle that sucks and holds the electronic component from the component supply position and the predetermined position of the circuit board on which the electronic component is mounted are positioned on the component mounting position, and the suction nozzle descends. In an electronic component mounting apparatus that mounts an electronic component on a circuit board by an operation and mounts the electronic component at a predetermined position on the circuit board by a suction release and ascending operation of a suction nozzle, a predetermined position of the circuit board And an image processing unit that determines whether the electronic component is mounted or not based on a difference image between the pre-mounting image and the post-mounting image captured by the image capturing unit. Is characterized by.

According to the electronic component mounting apparatus, the pre-mounting image and the post-mounting image captured before and after mounting the electronic component on the predetermined position of the circuit board are subjected to image processing to obtain a difference image, thereby obtaining the difference image on the circuit board. Only the mounted electronic component can be extracted, and the mounting state of the electronic component can be detected. By detecting the mounting state, it is possible to determine whether or not the electronic component has been mounted normally, and it is possible to improve the reliability of circuit board production.

In the above structure, the image pickup means can be constituted by a high-speed camera for continuously picking up the pre-mounting image and the post-mounting image corresponding to the mounting speed of the electronic component mounting,
It is possible to cope with speeding up of electronic component mounting operation.

Further, the image pickup means is provided with a camera for photographing the component mounting position from the same direction at the same magnification before the mounting and a camera for capturing the image after the mounting. It is possible to share the images and to capture both images during a short-time mounting operation in the electronic component mounting that has been speeded up.

Further, the image pickup means is provided with a focal depth adjusting means for adjusting the focal depth of the camera,
The depth of focus can be adjusted according to the size and mounting angle of the electronic component to obtain a fine image.

Further, by providing the slit light projecting means for projecting the slit light at the component mounting position, it is difficult to distinguish the color tone of the electronic component from the surface color of the circuit board in the same system. Also, the electronic parts can be easily recognized by the principle of light cutting.

Further, by providing the storage means for storing the image data and the mounting state detection data, it can be utilized for investigating the cause of the mounting failure, and can be effectively utilized for preventing the failure recurrence.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.
The embodiments described below are examples of embodying the present invention and do not limit the technical scope of the present invention.

FIG. 1 is a schematic diagram showing an embodiment in which a rotary head type electronic component mounting apparatus is provided with a configuration for detecting the mounting state of electronic components. A specific configuration of the rotary head type electronic component mounting apparatus is shown in FIG.
Although it is configured as shown in FIG.
As shown in FIG.

The rotary head 3, as shown in FIG.
A plurality of suction nozzles 2 are mounted on the circumference at equal intervals, and the suction nozzles 2 are intermittently rotated at intervals. The component supply position and the component mounting position are set on the circumference on which the suction nozzle 2 rotates intermittently, and the suction nozzle 2 that has moved to the component supply position by the intermittent rotation moves to the component cassette 31 or the like that has moved to the component supply position. The electronic component 1 is suction-held from the component supply unit. When the suction nozzle 2 that suction-holds the electronic component 1 moves to the component mounting position by intermittent rotation, the rotary head 3 lowers the suction nozzle 2 to mount the electronic component 1 suction-held on the circuit board 5. The circuit board 5 is fixed on the XY table 6, and is positioned by the XY table 6 so that the predetermined position for mounting the electronic component 1 is located at the component mounting position. Therefore, when the predetermined position of the circuit board 5 is positioned at the component mounting position and the suction nozzle 2 moved to the component mounting position is lowered, the electronic component 1 sucked and held is placed at the predetermined position of the circuit board 5, and the suction nozzle 2, the electronic component 1 is released from the circuit board 5 by lifting the electronic component 1 after releasing the suction.
Is installed at a predetermined position. The operation of each unit in the above configuration is controlled by the control device 11 so that the operations are synchronized with each other.

An image pickup device (image pickup means) 7 for picking up an image on the circuit board 5 at the component mounting position in order to detect the mounting state of the electronic component 1 mounted on the circuit board 5 with the above configuration.
A processing device 8 for processing the image data imaged by the imaging device 7, and a suction nozzle 2 by the rotary head 3.
Of a cycle timer 10 which outputs a timing signal to the processing device 8 in response to a reference signal for controlling the elevating and lowering operation of the electronic component 1 and a mounting state of the electronic component 1 on the circuit board 5 based on the data processed by the processing device 8 A control device 11 for generally controlling the operation of the component mounting device, and a storage device 1 for storing the determination result of the mounting state and various data necessary for mounting electronic components.
2 and are provided. Further, a slit light projector 9 for projecting slit light is provided on the circuit board 5 at the component mounting position.

The image pickup device 7 comprises one high-speed camera or two cameras and a dynamic depth of focus adjustment mechanism. If using two cameras,
As shown in, the two CCD cameras 50 and 51 are used, and the half mirror 55 is arranged on each optical axis, and C
Electronic components 1 on the circuit board 5 by the CD cameras 50 and 51
Are configured so that they can be imaged in the same state. In addition, the dynamic depth of focus adjustment mechanism, as shown in FIG.
The movable lens 58 is configured to be movable on the optical axis with respect to 7, and the camera is focused on the electronic component 1 on the circuit board 5.

The processing procedure for detecting the mounting state according to the above configuration will be described below with reference to the flow chart shown in FIG. 2 and FIGS. Note that S1, S2, ... Shown in FIG. 2 are step numbers indicating the processing procedure and coincide with the numbers added in the text.

FIG. 4 shows the suction nozzle 2 of the electronic component mounting apparatus.
The timings of the ascending / descending operation and the positioning operation of the XY table 6, and the imaging timing and the image processing timing by the imaging device 7 for the same are shown. The mounting sequence of the electronic components 1 on the circuit board 5 is set in the mounting program, and the suction nozzles 2 that suction-hold the electronic components 1 to be mounted.
4 moves to the time point A shown in FIG. 4, the image pickup means 7 uses the dynamic focal depth mechanism so that the electronic component 1 is within the focal depth of the camera based on the size information, the mounting position information, and the mounting angle information of the electronic component 1 to be mounted. Adjust to enter (S1). Along with the movement of the suction nozzle 2, the XY table 6 also moves in the XY directions to position a predetermined position of the circuit board 5 at the component mounting position and stop the moving operation. The image pickup device 7 picks up an image of a predetermined position of the circuit board 5 at time B shown in FIG. 4 when the circuit board 5 is positioned (S2). The image data captured by the imaging device 7 is immediately taken in by the processing device 8 and transferred to the control device 11. FIG. 3A shows an example of a captured image before mounting the electronic component 1. The electronic component 1 previously mounted on the circuit board 5 and the slit light projector 9 project onto the component mounting position S. The illuminated slit light 30 is visible.

The suction nozzle 2 that suction-holds the electronic component 1 moves toward the component mounting position S by the intermittent rotation of the rotary head 3 and at the same time gradually descends to the component mounting position S to descend the bottom dead center. 3B, the electronic component 1 is placed at a predetermined position on the circuit board 5 at time C shown in FIG. Since the suction nozzle 2 releases the suction of the electronic component 1 and ascends, the electronic component 1 is mounted on the predetermined position of the circuit board 5 (S3). When the electronic component 1 is mounted on the circuit board 5 with the stationary time of the XY table 6 being 14 ms, the imaging device 7 images a predetermined position of the circuit board 5 on which the electronic component 1 is mounted within the stationary time of the XY table 6. (S4). That is, as shown in FIG.
Since the pre-mounting image and the post-mounting image of the electronic component 1 are imaged within the stationary time of the table 6, when the image pickup device 7 is composed of one camera, a high-speed camera is used to display the pre-mounting image. The processing device 8 immediately captures the image data after the image capturing and prepares for capturing the image after mounting. As shown in FIG.
When two CCD cameras 50 and 51 are used, one CCD camera 50 is not attached and the other CCD camera 51 is attached.
Can be used for imaging after mounting. FIG. 3C shows an example of a captured image after the electronic component 1 is mounted. The slit light 30 projected to the component mounting position S is the shape of the electronic component 1 when the electronic component 1 is mounted. It becomes a shape bent along. When the color tone of the electronic component 1 is similar to the surface color of the circuit board 5, it may be difficult to recognize the electronic component 1 on the captured image, but the slit light 30 clearly identifies the presence of the electronic component 1.

The processing device 8 which has taken in the image before mounting the electronic component 1 and the image after mounting the electronic component 1 performs image correction on the vibration component from both images by a pattern matching method (S5), and obtains the difference image of both images. Create (S6). Figure 3
(D) shows an example of a difference image between the image of (a) in the figure and the image of (c) in the figure, and only the mounted electronic component 1 is extracted together with the slit light 30. The component mounting position S obtained from the difference image from the size information, mounting position information, and mounting angle information of the electronic component 1 acquired in the previous step S1.
The area including the is defined as the processing target area as shown in FIG. 3E (S7). The difference image in which this area is limited is binarized by a predetermined threshold value (S8), and then the noise unevenness filtering process removes the illumination unevenness and the minute vibration component before and after mounting (S9). Acquired,
This determination image is output to the control device 11.

The control device 11 performs a determination process using the determination image (S11), and when the mounting position and the mounting angle of the electronic component 1 are within the allowable range, it is determined that the mounting is normally performed (S11). If the mounting position and the mounting angle of the electronic component 1 exceed the allowable range, it is determined that the mounting is defective (S12). When it is determined that the mounting is defective, the control device 11 can perform a recovery operation of re-mounting the electronic component 1 that has become defective by changing the mounting procedure. Since the detection data of the mounting state is stored in the storage device 12, it can be utilized for investigating the cause of the defective mounting.

As described above, the images before and after mounting the electronic component 1 on the circuit board 5 are captured by the high-speed camera or two cameras, so that the transfer cycle of the captured image data is longer than the mounting speed. It can be applied even in the case. Further, the processing speed is fast because the data concerning the component mounting position and the mounting angle and the size of the electronic component 1 are acquired, the depth of focus is set in advance at the imaging position, and the image of the target area necessary for detection is extracted. It can be applied to a fast electronic component mounting device.

Although the electronic component mounting apparatus described above is of the rotary head type, it can be applied to a robot type electronic component mounting apparatus as shown in FIG. The robot-type electronic component mounting device positions and fixes the circuit board 5 at a predetermined position in the device, and the mounting head 35 having the suction nozzle 2 is freely moved in the horizontal direction by the XY robot 36. The electronic component 1 supplied from 38 is sucked and held by the suction nozzle 2 and mounted on the circuit board 5 at the electronic component mounting position. In the case of this robot type, electronic component 1
Since the suction nozzle 2 that has suction-held is moved onto the circuit board 5 whose position is fixed, the imaging device 7 is attached to the mounting head 35 to detect the mounting state of the electronic component 1.

When the mounting head 35 sucks and holds the electronic component 1 by the suction nozzle 2 and moves to the component mounting position on the circuit board 5, the imaging device 7 images the region including the component mounting position on the circuit board 5. To get the image before mounting. Next, the suction nozzle 2 is lowered to mount the electronic component 1 on the circuit board 5, the suction of the electronic component 1 is released, and the suction nozzle 2 is raised to image the region including the mounted electronic component 1. And get the image after mounting. The procedure for determining the quality of the mounting state of the electronic component 1 from the difference image between the pre-mounting image and the post-mounting image can be processed in the same manner as the case shown in the above embodiment.

[0035]

As described above, according to the present invention, the mounting state is detected from the difference image of the two images taken before and after the electronic component to be mounted at the predetermined position on the circuit board.
Image data processing is simple, there are few errors in software, and highly reliable detection is possible. Further, it can be applied to mounting electronic components with a short mounting state detection time and a high mounting speed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of an electronic component mounting apparatus according to an embodiment.

FIG. 2 is a flowchart showing a procedure for detecting a mounting state of electronic components.

FIG. 3 is a diagram illustrating an image processing procedure for detecting a mounting state (a) to (e).
FIG.

FIG. 4 is a timing chart for detecting a mounting state.

FIG. 5 is a schematic diagram showing the configuration of a dynamic depth of focus adjustment mechanism.

FIG. 6 is a schematic diagram showing a configuration of an image pickup apparatus using two cameras.

FIG. 7 is a perspective view showing the configuration of a rotary head type electronic component mounting apparatus.

FIG. 8A is a perspective view showing the configuration of a robot-type electronic component mounting apparatus, and FIG. 8B is a front view showing a state in which an imaging device is mounted on the mounting head.

FIG. 9 is a schematic view showing a configuration of mounting state detection according to a conventional technique.

[Explanation of symbols]

1 electronic components 2 adsorption nozzle 5 circuit board 7 Imaging device (imaging means) 8 Processing device (image processing means) 9 slit light projector

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshihiko Misawa             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Hirai Hi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Kazuyuki Nakano             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5E313 AA01 AA11 CC04 CD06 EE03                       EE24 FF24 FF29

Claims (9)

[Claims] 1. A suction nozzle that sucks and holds an electronic component from a component supply position and a predetermined position of a circuit board on which the electronic component is mounted are positioned on the component mounting position, and the electronic nozzle is lowered by the suction nozzle to move the electronic component to the circuit board. In an electronic component mounting method of mounting an electronic component on a predetermined position on a circuit board by a suction release and a lifting operation of a suction nozzle, the predetermined position of the circuit board is mounted before and after mounting the electronic component by an imaging means. An electronic component mounting method, characterized in that the quality of the mounting state of the electronic component is determined based on a difference image between a pre-mounting image and a post-mounting image. 2. The electronic component mounting method according to claim 1, wherein the depth of focus of the image pickup means is adjusted based on the size, mounting position, and angle data of the electronic component. 3. The electronic component mounting method according to claim 1, wherein the processing area of the difference image is adjusted based on the size, mounting position, and angle data of the electronic component. 4. A suction nozzle that holds an electronic component by suction from a component supply position and a predetermined position of a circuit board on which the electronic component is mounted are positioned on the component mounting position, and the electronic nozzle is lowered by the suction nozzle to move the electronic component to the circuit board. In an electronic component mounting device that is mounted on the electronic component mounting device and mounts the electronic component at a predetermined position on the circuit board by the suction release and ascending operation of the suction nozzle, the predetermined position of the circuit board is set before and after mounting the electronic component. Electronic component mounting, comprising: imaging means for capturing an image; and image processing means for determining whether the mounting state of the electronic component is good or bad based on the difference image between the pre-mounting image and the post-mounting image captured by the imaging means. apparatus. 5. The electronic component mounting apparatus according to claim 4, wherein the imaging means is a high-speed camera that continuously captures the pre-mounting image and the post-mounting image corresponding to the mounting speed of the electronic component mounting. 6. The electronic component mounting apparatus according to claim 4, wherein the imaging means includes a camera that images the component mounting position from the same direction at the same magnification and before and after the mounting. 7. The electronic component mounting apparatus according to claim 4, wherein the imaging means is provided with a focal depth adjusting means for adjusting a focal depth of the camera. 8. The electronic component mounting apparatus according to claim 4, wherein slit light projecting means for projecting slit light is provided at the component mounting position. 9. The electronic component mounting apparatus according to claim 4, further comprising storage means for storing image data and mounting state detection data.