JPH0278300A - Automatic mounting method of electronic component - Google Patents

Abstract

PURPOSE:To enable the automatic mounting of a component by a method where in the tentatively set position of the contact point row of the component is corrected by shifting the component if the amount of deviation of the bent contact point row is within the tolerance of mounting with regard to all contact points. CONSTITUTION:The image of an electronic component 5 held by a chuck 6 is taken against a screen as a background, which is processed to obtain the position and the rotating direction of the component 5. In this process, an ideal contact point pitch of the component 5 is previously set, and the positions of all contact points of the component 5 to be actually mounted are obtained and the center position of a contact point row is obtained. And, the actual positions of the contact points are compared with their normal positions, the contact points which deviate the most to the left or the right are noted, and the center position of a contact point row 10' is corrected so as to make the amount of deviation of these two contact points equal to each other. In this state, even if the position-aligned component 5 is possessed of a bent contact point row but its deviation is within tolerance, the component 5 can be mounted on a printed board 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for automatically mounting electronic components onto a printed circuit board, and more particularly, to a method for automatically mounting components for imposition of flat package ICs and the like.

[Conventional technology]

As a conventional automatic mounting method for electronic components, Japanese Patent Application Laid-Open No. 62-8
A technique described in Japanese Patent No. 6789 is known.

In this conventional technique, the part gripped by a chuck is imaged by a TV camera, etc., and this image information is processed to form a part with contact rows provided on each side of the part. Find the center position, and from the center position of the contact row of each spear part, find the center position and rotation direction of this imposition part, and based on this information, imposition the part U to the contact pattern of the flint board.
To ensure that the J contacts are aligned, the parts are moved by a robot and each contact is connected.

[Problem to be solved by the invention]

There is a measurement error in the position coordinates of each valley contact that makes up the contact array. However, in the conventional technology described above, the center position is calculated by calculating the average value of the position coordinates of each contact point, so the measurement errors for each contact point are canceled out, and the center position can be determined with high accuracy. . However, each contact is always in an ideal arrangement shape (this does not mean that all the contacts are in an ideal arrangement shape, and some surface mounting may occur during the contact installation process of the part (this may cause minor inconveniences or slight shocks during transportation of the completed part). The contact point of a certain part is bent.Ignoring the existence of this bend, the imposition calculates the center position and rotation direction of the part and mounts it on the printed circuit board. , it becomes impossible to connect the bent contact to the board pattern,
In this case, the component or the board module itself must be discarded as a defective product. In other words, if the contact force difference is small, the part itself cannot be said to be defective, but because of the automatic mounting process, it is considered to be a defective product, which lowers the yield of the product and increases costs. cause it to happen. This is because the conventional technology does not take into account the bending of the contact point UJ.

An object of the present invention is to provide an automatic mounting method for electronic components, which determines the position and rotational direction of electronic components by taking into account the bending of contacts, and reduces the incidence of defective products and costs.

[Means to solve the problem]

The above problem is an electronic component automation system that includes a printed circuit board transfer device, an electronic component supply device, and a robot that has a chuck for gripping electronic components and picks up the electronic components from the electronic component supply device and mounts them on the printed circuit board. In a mounting device, when mounting an electronic component having multiple UJ contacts arranged in a straight line on a printed circuit board, an image of the electronic component obtained by capturing an image of the electronic component gripped by a chuck with a blindfold board in the background is obtained. When determining the position and rotational direction of an electronic component by processing, the ideal distance between the contacts of the electronic component is determined in advance by 8], and the positions of all the contacts CIJ of the actually mounted Tl electronic component are set by 5, and the contact points are Temporarily set the center position of the contact row on the row,
Calculate the actual normal position of each contact from the contact spacing force measured in advance), and focus on the contacts whose actual position ti is most shifted to the left and the contact point whose actual position ti is most shifted to the right compared to the normal position. This is achieved by correcting the temporarily set center position of the contact row so that the amount of sliding between these two contacts OJ left and right (/J) is equal to the center position of the contact row.

[Effect]

According to the automatic mounting method of the present invention, by focusing on the contacts whose actual positions are farthest to the left and those whose actual positions are farthest to the right compared to the normal position, the left and right sides of these two contacts are The center position of the contact row was corrected to be equal to the center position of the contact row, so even if there are bent contacts, each contact can be adjusted by slightly shifting the mounting position of the electronic component. It becomes possible to connect to the pattern contacts on the board, making it possible to mount electronic components on the printed circuit board. Note that if the unit does not satisfy the required mounting accuracy (in this case, it is determined that it cannot be mounted).

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Fig. 2 is an external view of an automatic loading device to which the automatic loading method according to the present invention (/J-embodiment) is applied. The printed circuit board 2i is fixed at position 4. A contact pattern 2a is printed on this printed circuit board 2i.

The robot 6 is equipped with a chuck 68 that moves in the X and Y directions, and grips one electronic component supply bag [4] with the chuck 6. Then, the robot 6 moves to a position directly above the gripped electronic component 58 ``1'' V-camera 7 and stands still. FIG. 6 is a diagram illustrating the state at this time. The TV camera 7 is fixed upward so that the central axis of the chuck 6 and the optical axis are in the same direction. A dark-colored blindfold plate 9 is attached to the chuck 6 so that only the image of the camera sub-component 5 is captured.

When the TV camera 7 takes an image of the electronic component 5, the chuck 6 has its central axis aligned with the optical axis of the TV camera 7αj, and the distance between the electronic component 5 and the TV camera 7 is always constant.
It stops at the f and r positions, and the TV camera 7 (electronic parts 5
(IJ image +1!i X image from below.

The image of the electronic component 5 obtained by the TV camera 7 is shown in FIG.
The image data is sent to the image processing device 8 shown in FIG. Send thread information. The robot 6 corrects the posture of the electronic component 5 held by the chuck B according to the deviation information @ from the image processing device 8, so that each contact protruding from the side of the electronic component 5 conforms to the contact pattern of the board 2. Consistent with T
Install it as shown. When the electronic components 5 have been mounted on the printed circuit board 2, the board transfer machine 1 ejects the printed circuit board next to the mounted circuit board, fixes a new printed circuit board 2 in the same position, and repeats the same operation. , the child parts 58 are mounted on this new printed circuit board 2.

Figure 4 shows 'Method U for determining the position and rotation direction of electronic components.
) is a diagram explaining the principle. In Figure 4, six rectangles in the − column are
They are arranged in a square. The valley rectangle is electronic component 5-4
This is an image of n contacts, six on each side. From the arrangement of the contact images, the position coordinates (X, Y) of the center 0 of the electronic component 5 and the vector D indicating the rotational direction of the electronic component 5 are determined using the following procedure.

First, if the center positions of the six contact rows on each side (/J- row are points a, b, c, and d, respectively, then the center position of the contact row is a+
b+c+d(/Jm mark(ul+ v+L (uz, v
2) Find (u3.v3) l (u4+ v<). Then, find a straight line e that connects center positions a and c, and a straight line f that connects center positions [b and d, and @ the intersection point 8 of lines e and f.
Center position of basket part 5 ftO(X, Y)a-1,, [W
e.

The rotation direction of the electronic component 5 is calculated from the bisector f OJ (N) force).

Next, a method of determining the center position a''d of the contact row QJ will be explained.

First, as shown in FIG.
3 Input to the image processing device [8] under the same conditions as the image input. It is assumed that the approximate position and direction of rotation of the electronic components are determined by mechanical position constraint means such as mechanical chucks and pallets, and the position (this virtual line 108 is set) that crosses the contact row within the image sensor is assumed. .On this virtual line 10,
The coordinates of the point where the brightness of the image changes rapidly, that is, the boundary point (x mark) between the contact point and the back shape, are determined. Next, the coordinates of the bright molecule on the virtual line 10, that is, the brightness change point (marked x) on both sides of the contact point, are determined as the midpoint 8 contact point position (◯ mark). Then, the average position t of each contact point on the - column is determined, and finally, the distance between the average position and each contact position It, and the position 411jl of each contact point from the average position are recorded.

Next, image processing of the electronic components that will actually be installed (after getting stuck,
This will be explained with reference to FIG. First, in FIG. 5, (/JSimilarly to the explanation, the brightness distribution state 138 of the image on the virtual line 10' is determined, and the position of each contact point (white ○
Mark) Find 8. Next, find the average position 11 (0 mark) 8 of each contact position and use this as the virtual contact row center position. and,
The normal contact position data 8rPF of the ideal electronic component with no bending obtained in FIG. Compare jffi (← mark) and the actual position (○ mark), and find the contact point 1 that has the largest amount of sliding to the left (if there is no contact that is sliding to the left, the OJ that has the smallest amount of sliding to the right)
4, and the contact point 158 that has the largest deviation to the right (the smallest deviation is 0 to the left on the platform where there is no contact that is sliding to the right)
demand. Let ta be the contact 15 to the right (/J), and let tL be the negative contact 14 to the left.
, 15 to the left and right (La”tt,)
/ 2, by (tR-tt,) / 2,
The virtual contact row center position 1t (O mark) 8 right (scrubbing) is the contact row center position It a - d.For which hole in the contact row, l tR"tt, I / 2 is If the mounting error is larger than the allowable mounting error, the electronic component is discarded as a defective product.

As described above, according to this embodiment, for all the contact rows, the curved contact row 1t (tyt + tt)
If /2 is smaller than the allowable mounting error, the electronic component can be mounted on the printed circuit board as a good product without having to discard it as a defective product.

〔Effect of the invention〕

According to the present invention, electronic components that could not be mounted on a flint board conventionally as defective products due to bent contacts can be mounted as good products, which improves yield and reduces costs. There is.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining a method for mounting Kameko parts according to an embodiment of the present invention, and FIG. 2 is an external view of the own WtIJ mounting device.
The figure shows the positional relationship between the electronic component held in the chuck and the TV left camera, Figure 4 is an explanatory diagram for determining the position and rotation direction of the electronic component, and Figure 5 is an illustration of the electronic component without bending the contact point ζ. It is a figure explaining image processing. 1... Board transfer machine 2... Printed circuit board 3...
Robot 4...Electronic component supply device 5...Electronic component 698. Chuck 7...TV camera 8...
Image processing bag [9...Blind plate 10...Virtual line 11...Contact boundary point 12...Contact position 15.
...Brightness distribution state on the virtual line 14... Left facing contact point 15... Right Fig. 1, Fig. 42, Fig. 5, Fig. 44, Fig. 5

Claims (1)

[Claims] 1. In an electronic component automatic mounting device comprising a printed circuit board transfer device, an electronic component supply device, and a robot having a chuck for gripping electronic components and picking up and carrying the electronic components from the electronic component supply device and mounting them on the printed circuit board. When mounting an electronic component with multiple contact points arranged in a straight line on a printed circuit board, the electronic component gripped by the chuck is imaged with a blinding board as a background, and the image of the electronic component obtained is processed to create an electronic component. To find the position and rotation direction of the electronic component, measure the distance between the contacts of the ideal electronic component in advance, find the positions of all the contacts on the electronic component that will actually be mounted, and then set the center position of the contact row on the contact row. Temporarily set, find the actual normal position of each contact from the previously measured contact spacing, and compare the actual position to the contact whose actual position is farthest to the left and the contact whose actual position is farthest to the right. An electronic component automatic mounting method is characterized in that the center position of a contact row, which is temporarily set so that the left and right deviation amounts of these two contacts are equal, is corrected to become the center position of a contact row.