JPH0645796A - Part mounting method - Google Patents

Abstract

PURPOSE:To enable an image processing operation and the synthesis of image to be easily carried out for obtaining corrections and to change a camera used for recognition corresponding to a part by a method wherein a part and a mounting land are prescribed in positional relation between them to accurately mount a part, a recognition means, a part, and a mounting land are prescribed so as to cross each other at a right angle, and a reference position is set so as to be picked up by every camera. CONSTITUTION:A rectangular mounting part 3 is taken out of a part feeder 4, and the part 3 is transferred to a mounting position on a board 5 and mounted on a mounting land 9, where the mounting part 3 or the mounting land 9 are recognized from a direction nearly vertical to the end edge of either the mounting part 3 or the mounting land 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component mounting apparatus for accurately positioning a component with respect to a predetermined mounting position on a board by a recognizing means and mounting the component on a printed circuit board.

[0002]

2. Description of the Related Art Generally, when a component is automatically mounted on a board, the component is picked up by a component transfer head from a feeder that supplies the component, and the component is mounted on a board at a preset component mounting position. Carry to implement.

Especially when a surface mounting component having a very large number of leads is used as a component, the pitch between adjacent leads is small, and miswiring occurs even if the positions are slightly displaced.

Therefore, in order to prevent miswiring, the position of the component and the position of the board on which the component is mounted are detected, and the both are aligned, so that the component is accurately mounted at a predetermined position on the substrate. Is required.

As a mounting method of such a component, as shown in Japanese Patent Laid-Open No. 60-1900, the center position and the rotation angle of the component are determined from the image of the lead of the component, and the mounting pattern is determined from the image of the board. Two I formed at the same time
It is proposed that the center position and the rotation angle of the mounting pattern are determined by the C mark, and the component transfer head is moved / rotated according to the obtained positional relationship between the component and the mounting pattern to mount the component at a predetermined position on the substrate. (Hereinafter, conventional example 1
That).

Further, even if the positional relationship between the component and the mounting pattern is accurately and precisely defined and the component can be mounted on the mounting pattern with high precision, an adhesive or cream solder for temporarily attaching the component and the mounting land is used. There is a possibility that misalignment may occur immediately after mounting due to printing defects, etc., and it is possible to detect these misalignments and prevent the board with improper mounting from flowing in the next process (reflow oven, etc.). There is.

A method for judging the quality of mounting of such components is disclosed in, for example, Japanese Patent Laid-Open No. 63-90707, but this method is based on the positional relationship of land images before and after mounting. Japanese Patent Laid-Open No. 1-309190 discloses that
A technique for making a determination from the amount of overlap of land images before and after mounting is shown (hereinafter referred to as Conventional Example 2).

Further, conventionally, mounting of components on a board is performed by a component mounting machine, and the quality of this mounted component is judged by a mounted component inspection machine in the next step after completion of component mounting of the entire board, or A visual inspection was performed (hereinafter referred to as Conventional Example 3).

[0009]

However, in Conventional Example 1, when the mounting position of a component is corrected from the obtained positional relationship between the component and the mounting pattern, the positional relationship between the mounting pattern and the IC mark, and the component If the positional relationship of the imaging means between the board and the board is not accurately and accurately defined, the component cannot be mounted on the mounting pattern with high accuracy.

Further, a fine chip component or a leaded component with a narrow lead pitch, which requires high mounting accuracy, requires two IC marks for each component, so that high-density mounting cannot be performed.

Further, in the conventional example 2, all are methods for realizing as an inspection machine after mounting, and the reference for comparison is a taught one or a reference board, so that the board to be actually mounted is used. Absent. For this reason, it is necessary for the variation of the mounted boards themselves to have a fixed value as an allowable range.

Further, in the conventional example 3, when the quality of the mounted component is visually judged, it is not possible to obtain sufficient inspection accuracy for a fine chip component or a leaded component having a narrow lead pitch, and However, evenness cannot be expected due to individual differences and fatigue.

Therefore, the mounting component inspection machine is installed in the next process of the component mounting machine. However, both need to input data such as the component mounting position and the component inspection position and adjust the input data, and therefore the mounting board is concerned. The data creation time increases, the operator's burden is increased, and it becomes difficult to support various types of mounting boards.

The present invention has been made in order to solve such a problem, and an object of the present invention is to accurately mount a component by defining the positional relationship between the component and a mounting land, and to recognize the recognizing means. And the parts and mounting lands are defined to be orthogonal to each other, and the reference position is generated so as to be viewed from any camera, so that image processing calculation and image composition for extracting the correction amount can be easily performed. The object of the present invention is to provide a component mounting method in which the camera used for recognition is switched according to the component.

[0015]

In order to achieve the above object, in the invention according to claim 1, a rectangular mounting component is taken out from the component supplying device, and the mounting component is moved to a predetermined component mounting position on the substrate. In a component mounting method of transferring and mounting on a mounting land, the mounting component or the mounting land is recognized from a direction substantially perpendicular to an edge of at least one of the mounting component or the mounting land. To do. In the invention according to claim 2, the recognizing means provided in the component transfer head for transferring the mounted component recognizes the mounted component and the mounting land, and transfers the corresponding feature point of the mounting component and the mounting land to the component transfer. It is characterized in that the positional relationship is defined with respect to the head.

According to a third aspect of the present invention, the recognizing means is composed of at least two cameras having a symmetrical positional relationship with each other. According to the invention of claim 4,
Rectangular mounting parts are equipped with lead terminals that extend in two directions,
It is characterized in that the mounting component and the mounting land are recognized from the direction in which the lead terminal is recognized. The invention according to claim 5 is characterized in that the mounting component and the mounting land are recognized from the direction of the short side or the long side of the rectangular mounting component.
According to a sixth aspect of the invention, the recognizing means is composed of two pairs of cameras having a symmetrical positional relationship with each other, and each pair is selectable according to the recognizing direction.

[0017]

With the above construction, in the present invention, (1) a rectangular mounting component is taken out from the component supplying device,
This mounted component is transferred to a predetermined component mounting position on the board and mounted on a mounting land.When mounting, mounting is performed from a direction substantially perpendicular to the edge of at least one of the mounting component and the mounting land. By recognizing the component or the mounting land, the relationship between the captured image and the pixels of each camera becomes parallel or at a right angle, so that the image processing and the image synthesis are simplified. (2) The mounting component and the mounting land are recognized by a recognition unit such as a camera provided in the component transfer head. For example, the tip of the component transfer head is stored as a reference position in the recognition unit and the reference is stored. By including the position in the field of view of the camera, the combining operation for combining a plurality of images can be easily performed.

(3) The recognizing means arranges, for example, four cameras with a shift of about 90 degrees around the component transfer head, or two cameras with a shift of about 180 degrees. , Cameras which are in a symmetrical positional relationship with each other. (4) When recognizing a rectangular mounting component having lead terminals extending in two directions, the mounting component and the mounting land are recognized by the camera provided in the direction in which the lead terminal is recognized. (5) When the mounted component is rectangular, the mounted component and the mounting land can be recognized by the camera provided in the direction of the short side or the long side. (6) The recognizing means is composed of two pairs of cameras having a symmetrical positional relationship with each other, and each pair of cameras can be arbitrarily selected according to the recognizing direction.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the component transfer head 1 and the cameras 2-1, 2-2, 2-3, 2-4 are mounted on the same base and can be transferred in the XY directions. Further, the component transfer head 1 has a mechanism capable of transferring in the vertical direction and the rotational direction. Four (or two) cameras are arranged with the component transfer head 1 as the center, and the imaging (or recognition) direction of each camera is orthogonal to the component, and the transfer head 1 is obliquely mounted. Has a field of view in the direction of movement.

By combining the visual fields using a plurality of cameras in this way, the visual field resolution of the cameras is enhanced, the shadowed portion of the component transfer head 1 can be recognized, and the height information of the object to be recognized can be obtained. It is easy to obtain, and it is possible to suppress the appearance of the component transfer head 1 in the visual field (hereinafter, the unit of the component transfer head 1 and the recognition camera is referred to as a "transfer recognition unit").

Since the transfer recognition unit moves in the XY directions, but the camera does not move up and down, the camera is focused on a certain surface with respect to the movement of the transfer recognition unit (see the camera of FIG. 1). The focus surface 8 is shown). Therefore, the pattern of the component and the board 5 to be mounted must be on this surface. However, conversely, unless a background or the like that is not desired to be imaged is not on this surface, the image is not focused because the camera is out of focus and the influence of the background can be suppressed.

The steps until the components are recognized and mounted by using the above-mentioned structure will be described below. 2 (a) and 2 (b) show the state at the time of component recognition. The component transfer head 1 sucks the mounted component 3 from the feeder 4, lifts it up to the focusing surface 8 of the camera, picks up images with the cameras 2-1, 2-2, 2-3, 2-4, and stores it in the frame memory. The composite image obtained at this time is shown in FIG.

After that, the component transfer head 1 rises to a height at which it can pass and moves to the board recognition point 7 in FIG. In balance with the operation, the component position recognition processing is performed with the component transfer head 1 as a reference.

Next, the state at the board recognition point 7 is shown in FIG.
Shown in (a) and (b). Since the component transfer head 1 is located above, the focus of the cameras 2-1, 2-2, 2-3, 2-4 matches the mounting land 9 on the substrate surface. A composite image obtained by imaging in this state is shown in FIG. Since this image is also obtained by the same camera as in FIG. 2C, the position of the mounting land can be recognized with the component transfer head 1 as a reference.

Since the positional information of the component obtained in FIG. 2C and the positional information of the board of the mounting land 9 obtained in FIG. 3C are recognized with reference to the component transfer head 1. The absolute accuracy of the entire apparatus is not required, but the parts and the lands are corrected so that they are corrected, and as a result, highly accurate mounting is possible.

That is, since the same camera can recognize parts and lands, and the head, which is the center of transfer, can also be recognized by the same camera, the error component can be suppressed and high-accuracy mounting is possible ( Fig. 4 shows the component mounting state.

As shown in FIGS. 7 (a) and 7 (b), the head is lowered to the focusing surface (hereinafter referred to as the recognition surface) 8 of the camera, and the image is taken by each camera.
As in (f), the tip portion of the head imaged by each camera is stored as a reference position for each camera. This is because tact is increased if the reference position is calculated each time recognition is performed. By including the reference position in the field of view of each camera, the images of the cameras can be combined using the reference position, and the combining operation can be easily performed.

Next, an inspection after mounting is performed. Even if highly accurate positioning is performed by the above method, the state of cream solder at the time of mounting, the air pressure of the transfer head being cut off, and the vibration at the time of mounting. Due to this, parts may move or parts may stand up. Therefore, inspection is performed after mounting.

After mounting, the state where the component transfer head 1 is lifted up is shown in FIGS. 5 (a) and 5 (b), and the combined image obtained at this time is shown in FIG. 5 (c). Since this composite image is stored in the frame memory, the transfer recognition unit can go to the next mounted component.

Next, FIG. 6 shows an image of image extraction. That is, an image of the mounting land 9 before mounting (see FIG.
Image comparison processing of (c)) and the image after mounting (FIG. 5C) is performed to obtain a component image after mounting. From this image,
The position of the mounted component can be recognized with the component transfer head 1 as a reference. By comparing this position information with the position information of the component before mounting, which is obtained from FIG. 2C, using the component transfer head 1 as a reference, the mounting state of the component after mounting can be recognized. .

As a result, the apparatus can judge whether the mounted components are mounted normally, the operator can be informed of the abnormality, and the positional deviation information can be returned to the next mounting data. .

In this embodiment, as a mounting apparatus having a recognition function, this function is used not only for alignment but also as an inspection function for the mounting state after mounting. Moreover, since the recognition is performed immediately after mounting, there is almost no time loss due to the inspection, and an inspection device is not required for the subsequent process unlike the conventional case. Therefore, the teaching of the position required for the inspection machine is not necessary, the number of steps before curing is reduced, and there is no risk of careless displacement of parts. That is, the entire line can be downsized, the teaching time and the product type switching time can be shortened, and the defective factors can be reduced.

In this way, it is not necessary to install a mounting inspection machine by performing high-precision mounting by recognizing components and mounting lands with the same camera, and performing inspection after mounting. The above capabilities can be demonstrated.

Next, a series of flow from mounting to inspection will be described with reference to FIGS. In FIG. 8, step 1
At 01, rough teaching of the mounting position and accompanying mounting data are input, and then the process proceeds to the mounting data optimizing step. In this process, in step 102, the component is moved to the component supply position and the component is taken out based on the component supply position data, and in step 103, the component image information is captured and the component head position information is calculated based on the transfer head. I do.

At this time, FIG. 11C shows a captured image of the camera 2-1. However, as shown in FIGS. 11A and 11B, each camera is orthogonal to the rectangular mounting component. As shown in FIG. 11D, the relationship between the captured image and the pixels of each camera is parallel and at a right angle, which simplifies image processing (feature position extraction calculation) and image composition. The same applies to the mounting positions corresponding to the components.

At step 104, movement to the component mounting position based on the teaching data is performed. Step 105
Then, the board image information is captured, the mounting land for the mounted component is searched and extracted based on the extraction result of the component information, and the mounting land position information is calculated based on the transfer head.

In step 106, the mounting position that minimizes the difference in the positional relationship between the corresponding feature points of the component position and the mounting land position with respect to the transfer head is calculated. Step 107
Then, the mounting position data is updated, and in step 108, movement to the optimum mounting position and component mounting are performed.

In step 109, it is judged whether or not the component requires mounting accuracy. If YES, the process proceeds to the actual operation process of step 110 (FIG. 9), and if NO, step 119.
To the actual operation process (Fig. 10).

Thus, in step 110 of FIG. 9, the component is moved to the component supply position and the component is taken out based on the component supply position data, and in step 111, the component image information is taken and the transfer head is used as a reference. The component position information is calculated. The information on the component position calculated here is used for updating the data in step 117, and the updated data is used in step 110.
It is designed to be input to.

In step 112, the component is moved to the component mounting position based on the component mounting data, and in step 113, the board image information is captured and the mounting land for the mounted component is searched and extracted based on the extraction result of the component information.
The mounting land position information is calculated based on the transfer head.

The mounting land position information calculated here is
It is used to update the data in step 118, and the updated data is input to step 112. Then, in step 114,
The mounting position that minimizes the difference in the positional relationship between the corresponding feature points of the component position and the mounting land position with respect to the transfer head is calculated, and in step 115 the component is moved to the optimum mounting position and the component is mounted. The position information of the mounted component is extracted by capturing the image information, the component mounting information is calculated based on the transfer head, and the quality of mounting of the component based on the transfer head is determined.

Next, when the mounting accuracy is not required, as shown in FIG.
In step 119, the component supply position is moved and the component is taken out based on the component supply position data. In step 120, the component image information is captured and the component position information is calculated based on the transfer head. The component position information calculated here is used for updating the data in step 126, and the updated data is input to step 119.

Subsequently, at step 121, the component mounting position data is corrected based on the component position information with the transfer head as a reference, and the component mounting position is moved to the component mounting position corrected at steps 122 to 124 and the board image information is taken. In step 125, the board image information is captured to extract the position information of the mounted component, the component mounting position information is calculated with the transfer head as a reference, and the transfer head is used as a reference. The quality of the mounting of the component is determined by comparing the information obtained.

The board image information in step 123 and the component mounting position information calculated in step 125 are used for updating the data in step 127, and the updated data is input to the previous step 121. It is like this.

By the way, when mounting leads extending in four directions as shown in FIGS. 1 to 6 at the corresponding mounting positions,
Since it is necessary to define the X and Y directions with accuracy, it is necessary to recognize the leads from four directions and the mounting positions corresponding to them. However, as shown in FIGS. 12 to 17 (corresponding to FIGS. 1 to 6). When recognizing the mounting position corresponding to the lead extending in two directions as described above, only the accuracy for defining the Y direction is necessary.
The X direction does not require high precision. Therefore, in this case, as shown in FIGS. 13A to 13C and FIGS. 14A to 14C,
The correction amount is calculated by recognizing only the two cameras in which the two leads at the symmetrical positions or the corresponding lands appear to be linear.

18 (a) to 18 (f) show the details of the component recognition method. In FIGS. 18A and 18B, each camera 2-
Since the field of view is different for each of 1, 2, 2, 2-3, 2-4,
The captured images are also different, and the images shown in FIGS.
A recognition image is obtained by combining the images of (f).

19A to 19F show details of the board recognition method. 19A and 19B, each camera 2-
Since the field of view is different for each of 1, 2, 2, 2-3, 2-4,
The captured images are also different, and the images shown in FIGS.
A recognition image is obtained by combining the images of (f).

20 to 25 show a mounting method of a mounting component without lead legs, which correspond to FIGS. 1 to 6 already described.

FIG. 26 shows a flow chart for switching the recognition camera without using a camera when mounting a component having leads extending in two directions. That is, the direction of the mounting land is stored, the direction of the land is compared with the terminal direction of the component, and when they match, the camera recognizes the component in the same direction as the terminal. The parts are recognized by the direction camera.

FIG. 27A shows switching using a camera, which is judged by the presence / absence of a lead. That is, the image is picked up by four cameras, image processing is performed to select the camera in the direction in which the lead exists, and the selected camera recognizes the part. FIG. 27B shows switching using a camera, but when the external dimensions of the component are long or short, the determination is made in the direction in which the long side exists. For example, the parts are imaged by four cameras, image processing is performed to select the camera in the direction in which the long side exists, and the parts are recognized by the selected cameras.

[0051]

The present invention has the following effects. (1) Since the same camera recognizes the component and the mounting land with the component transfer head as a reference, it is possible to perform highly accurate alignment without requiring the precision of the entire apparatus. Further, the mounting state of the component can be inspected by comparing the positions of the image after mounting and the image obtained for mounting, and the inspection machine is not required in the subsequent process. Therefore, elements such as teaching of the inspection machine, switching of product types, and occurrence of defects by the inspection machine are eliminated, and the defect determination line can be connected immediately after the mounting apparatus. Further, the mounting deviation data can be accumulated and returned to the subsequent mounting data, which enables more accurate mounting.

(2) By recognizing the mounting components and the mounting lands from a direction substantially perpendicular to the sides of the mounting components and the mounting lands, the captured images of them are parallel to each other and are perpendicular to each other. Processing calculation and image composition are simplified.

(3) The tip of the component transfer head is imaged on the recognition surface in the field of view of each camera without using a special jig, a reference position is generated, and the reference position is stored.
Preventing an increase in recognition calculation and simplifying the combination calculation.

(4) When recognizing leads extending in two directions such as SOP (parts in which leads extend in two directions) with two symmetrical cameras, the images are first recognized by the four cameras,
It is inspected whether the lead is in the same direction as the land to be mounted, and thereafter, recognition is performed by the camera corresponding to the extending direction of the lead. That is, by checking the difference in the direction from the mounting land and automatically switching the recognition camera, it is possible to recognize whether a component such as SOP is supplied in the vertical or horizontal direction.

(5) The correction amount can be calculated by using the same image processing calculation even if the shapes of the components are different, using only the cameras corresponding to the side where the terminals of the mounting components and the mounting lands are arranged.

(6) For any part, once the part is recognized by all cameras and image processing is performed, the recognition camera suitable for the part can be automatically selected.

[Brief description of drawings]

FIG. 1 is a diagram showing a recognition mounting operation.

FIG. 2A is a front view showing a state at the time of component recognition,
(B) is the top view, (c) is a figure which shows the synthetic image of components.

3A is a front view showing a state at the time of recognition at a board recognition point, FIG. 3B is a plan view thereof, and FIG. 3C is a view showing a composite image of the boards.

FIG. 4 is a front view showing a component mounting state.

FIG. 5A is a front view showing an inspection state after component mounting,
(B) is the top view, (c) is a figure which shows the composite image of a component mounting state.

FIG. 6 is a diagram showing an image of image extraction.

7A is a front view when a reference position is generated, FIG. 7B is a plan view thereof, and FIGS. 7C to 7F are views showing images captured by a camera.

FIG. 8 is a diagram showing a flowchart from component mounting to inspection.

FIG. 9 is a diagram showing a flowchart from component mounting to inspection.

FIG. 10 is a diagram showing a flowchart from component mounting to inspection.

11A is a front view showing a positional relationship between a mounted component and a camera, FIG. 11B is a plan view thereof, FIG. 11C is a view showing a captured image of the camera, and FIG. 11D is a captured image. It is a figure which shows the relationship of the pixel of each camera.

FIG. 12 is a diagram showing a recognition mounting operation of a bidirectional leaded component.

FIG. 13A is a front view showing a state at the time of component recognition,
(B) is the top view, (c) is a figure which shows the synthetic image of components.

14A is a front view showing a state at the time of recognition at a board recognition point, FIG. 14B is a plan view thereof, and FIG. 14C is a view showing a composite image of the boards.

FIG. 15 is a front view showing a component mounting state.

16A is a front view showing an inspection state after component mounting, FIG. 16B is a plan view thereof, and FIG. 16C is a diagram showing a composite image of the component mounting state.

FIG. 17 is a diagram showing an image of image extraction.

FIG. 18 (a) is a front view at the time of component recognition, FIG. 18 (b) is a plan view thereof, and FIGS. 18 (c) to 18 (f) are views showing images taken by a camera.

FIG. 19 (a) is a front view at the time of board recognition, FIG. 19 (b) is a plan view thereof, and FIGS. 19 (c) to 19 (f) are views showing images captured by a camera.

FIG. 20 is a diagram showing a recognition mounting operation of a mounting component without lead legs.

FIG. 21 (a) is a front view showing a state at the time of component recognition,
(B) is the top view, (c) is a figure which shows the synthetic image of components.

22A is a front view showing a state at the time of recognition at a board recognition point, FIG. 22B is a plan view thereof, and FIG. 22C is a view showing a composite image of boards.

FIG. 23 is a front view showing a component mounting state.

24A is a front view showing an inspection state after component mounting, FIG. 24B is a plan view thereof, and FIG. 24C is a diagram showing a composite image of the component mounting state.

FIG. 25 is a diagram showing an image of image extraction.

FIG. 26 is a diagram showing a flowchart for switching recognition cameras without using a camera.

FIG. 27 is a diagram showing a flowchart of switching of a recognition camera using a camera.

[Explanation of symbols]

 1 Component Transfer Head 2-1, 2-2, 2-3, 2-4 Camera 3 Component 5 Board 6 Component Recognition Point 7 Board Recognition Point 8 Camera Focusing Surface 9 Land

Claims (6)

[Claims] 1. A component mounting method for picking up a rectangular mounting component from a component supply device, transferring the mounting component to a predetermined component mounting position on a board, and mounting it on a mounting land. 2. The component mounting method, wherein the mounting component or the mounting land is recognized in a direction substantially perpendicular to at least one of the edges. 2. The recognizing means provided in the component transfer head for transferring the mounted component recognizes the mounted component and the mounting land, and the corresponding characteristic points of the mounted component and the mounting land are determined based on the component transfer head. 2. The component mounting method according to claim 1, wherein the positional relationship is defined as 3. The component mounting method according to claim 2, wherein the recognizing means is composed of at least two cameras having a symmetrical positional relationship with each other. 4. The mounting component having a rectangular shape is provided with a lead terminal extending in two directions, and the mounting component and the mounting land are recognized from a direction in which the lead terminal is recognized. Parts mounting method. 5. The component mounting method according to claim 1, wherein the mounting component and the mounting land are recognized from the direction of the short side or the long side of the rectangular mounting component. 6. The component mounting according to claim 4, wherein said recognizing means is composed of two pairs of cameras having a symmetrical positional relationship with each other, and each pair is selectable according to the recognizing direction. Method.