JPH04332198A - Part mounting apparatus - Google Patents

Abstract

PURPOSE:To prevent damage of electronic parts and improve mounting tact time by forecastingly calculating a region where leads within part imaging screen exist to detect desired leads among the scanning lines of imaging means of only such region and by calculating center coordinates and gradient of the parts as a whole to carry out compensation of position. CONSTITUTION:A region of the part forecasting existence of electronic parts and leads among an imaging data, namely a video data of electronic parts is calculated with a measuring window calculating means 21. Only the predetermined number of leads on one side of an electronic part are effectively and independently detected only for such region with an IC lead detecting means 23 and moreover the center coordinates in the four directions of an electronic part are calculated by an IC center gradient calculating means 24 while recognition failure is prevented, even if deflection to the rotating direction of an electronic part is large. Thereafter, displacement of an electronic part is calculated by a mounting compensation data transmitting means 25 and the data obtained is transmitted to a mounting device controller 19.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component mounting apparatus for automatically mounting electronic components and the like on a board at high speed and with high precision.

0002

2. Description of the Related Art Conventionally, in a component mounting apparatus, a method for mounting electronic components and the like on a board has been realized, for example, by the apparatus configuration shown in FIG.

A suction head 2 that suctions the electronic component 1, a positioning stage 3 that mechanically positions the electronic component 1 that is suctioned by the suction head 2, and a positioning stage 3 that mechanically positions the electronic component 1 that is suctioned by the suction head 2. A camera 5 on the stand 1 that takes an image, and a second camera 5 that takes an image of the board mark 7 on the printed circuit board 6.
The camera 8 and the first and second cameras 5 and 8 are controlled to recognize the positions of the electronic component 1 and the printed circuit board 6, and to obtain correction data for the electronic component 1 and the printed circuit board 6 based on the recognition data and reference data. A visual recognition controller 9 that performs calculations;
Based on the correction data from this visual recognition controller 9,
It is composed of a mounting machine controller 10 that relatively corrects the positions of the electronic component 1 and the printed circuit board 5.

Further, as shown in FIG. 12, the positioning stage 3 has a regulating head 11 for regulating the position of the electronic component 1 from four directions. In the component mounting apparatus configured in this way, the electronic components 1 are picked up one by one by the suction head 2 from a packaging hard case (not shown), placed on the positioning stage 3, and then the regulating head 11 picks up the electronic components 1 one by one. The electronic component 1 is sandwiched from four directions. This mechanically corrects the suction position of the electronic component 1 with respect to the suction head 2 (X, Y, Q
direction). This is called prealignment.

After this pre-alignment, the suction head 2 again suctions the electronic component 1 and moves it onto the first camera 5.
Therefore, the positional misalignment between the electronic component 1 and the suction head 2 is once again captured by visual recognition, and highly accurate correction data is sent to the mounting machine controller 10 for mounting. Therefore, a conventional method for recognizing electronic components will be further described. FIG. 13 shows a model of the visual recognition method for the electronic component 1, in which the electronic component 1 suctioned and fixed to the suction head 2 is imaged by the first camera 5.

After imaging the electronic component 1 with the first camera 5 in this way, the image data is sent to the visual recognition controller 9.
All the stored image data was stored in the internal image memory, and all of the stored image data was binarized, and then the arithmetic processing described below was performed to calculate the center of gravity and slope of the binarized image of the captured image. . When the optical system uses transmitted light, the top of the electronic component 1 is imaged in a dark state and the rest is bright.

In addition, in FIG. 13, the measurement field of view A is
All areas that can be imaged by the first camera are shown. The four corner points of the measurement field of view A are the measurement field of view origin A1 , end point A2 , A
3, A4. Parallel to the X-axis starting from the origin A1 of this measurement field of view A (=parallel to the scanning line of the camera)
Extract the binarized image data. This is performed sequentially in the Y-axis direction. The data obtained here is the straight line L in Figure 13.
If it is on the lead 4 as in No. 1, a sawtooth shape can be obtained. Therefore, the center of each lead 4 is detected. The center of the entire lead group is calculated from this center. Next, if one side of the electronic component 1, that is, the center of the lead group, is taken as the center of all the lead parts, this point can be calculated as the center of gravity of each lead center. If this operation is performed on all four sides of the electronic component 1, its center coordinates and inclination will be detected.

In FIG. 13, a lead midpoint O1 is detected by drawing a straight line L1 above the lead of the electronic component 1. The lead midpoint O2 is detected by drawing a straight line L2 on the left side of the lead. Similarly, the straight line L3,
By applying L4 to the lower and right parts of the leads, the lead midpoints O3 and O4 are detected. Next, a method of calculating the center G, which is the center of gravity position of the electronic component 1, and the inclinations θ1 and θ2 from these lead midpoints O1, O2, O3, and O4 will be explained.

If the straight line connecting the lead midpoints O1 and O3 is a straight line L, and the straight line connecting the lead midpoints O2 and O4 is a straight line M, the intersection of these two straight lines is the IC measurement center of gravity G. , it is possible to obtain the inclinations of these two straight lines in the X-axis and Y-axis directions as IC inclinations θ1 and θ2. The calculation formula is as follows. The coordinates of the lead midpoints O1 to O4 are determined as follows. Lead midpoint O1: (xa, ya) Lead midpoint O2: (xb, yb) Lead midpoint O3
: (xc, yc) Lead midpoint O4 :
(xd, yd) Equation of straight line L: (X
-xa)×(yc-ya)=(xc-xa)×(Y-y
a) Equation of straight line M: (X-xb) x (yd-
yb) = (xd-xb) x (Y-yb) Coordinates of IC measurement center of gravity G: Value of IC inclination θ1 below: θ1 = tan-1 [(
yd-yb)/(xd-xb)] Value of IC slope θ2: θ2 = tan-1[(
yc-ya)/(xc-xa)]

[0010]The final inclination of the electronic component is IC inclination θ1
, θ2 is sent to the mounting machine controller 10 as the average value.

By detecting the center of gravity position of the conventional board mark using the above-mentioned means and comparing the detected value with the amount of deviation from the camera center position, the amount of positional deviation and inclination of the suction head 2 and the electronic component 1 can be determined. has been detected and the actual mounting onto the printed circuit board 6 has been carried out while correcting the positional deviation. [Intersection of straight lines L and M, that is, IC center coordinates G]X=(mb
-lb)/(la-ma) Y=(la×mb-lb×ma)/(la-ma) However, la, lb, ma, mb are la=(ya-yc)/(xa-xc) lb =(xa×
yc-xc×ya)/(xa-xc)ma=(yb-y
d)/(xb-xd)mb=(xb×yd-xd×yb
)/(xb-xd) The above is the conventional method of IC mounting procedure.

Here, the reason why the electronic component 1 passes through the positioning stage before being imaged by the first camera 5 is that the above recognition method is weak against rotational deviation of the electronic component 1 in the θ direction. be.

That is, in FIG. 13, if the electronic component 1 is tilted significantly, the straight lines L1 to L4 for detecting the leads 4 will not be able to scan all the leads 4 on one side of the electronic component 1 at the same time. However, when the electronic component 1 is taken out from the hard case for direct packaging, there is a possibility that the electronic component 1 is rotated significantly with respect to the suction head 2 not only in the X-Y axis direction but also in the θ direction. Therefore, the positioning stage 3 has become essential.

[0014]

[Problems to be Solved by the Invention] In recent years, the leads and lead pitches of electronic components have tended to become denser and more diverse. Therefore, two problems have arisen as described below.

First, as the lead density of electronic components increases, the leads themselves are becoming extremely thin and thin. For example, with TAB parts that have been put into practical use in recent years, if the position is corrected using a conventionally used positioning stage, there is a possibility that the TAB leads will be bent and damaged.

Furthermore, a second problem is that it is difficult to shorten the takt time for mounting electronic components. When electronic components are mounted using a conventional positioning stage, the correction operation of the electronic components occupies a large portion of the entire takt time, making it impossible to shorten the mounting tact time. The above problem occurs because the image processing algorithm for electronic component recognition has a low ability to recognize deviations in the rotational direction of electronic components.

Therefore, the present invention was made to solve the above two problems, and its main purpose is to eliminate the need to pass through a positioning stage after taking out the electronic component from its hard case, even if the electronic component is rotated in the direction of rotation. The purpose of the present invention is to provide a component mounting device that prevents damage to electronic components and improves mounting takt time by providing a function that enables direct visual recognition using a camera for electronic component recognition even if there is a large deviation in the electronic component. . [Structure of the invention]

[0018]

[Means for Solving the Problems] Therefore, in order to achieve the above object, the present invention provides a component mounting apparatus having means for visually recognizing electronic components, etc., which includes an imaging means for capturing an image of the electronic components, etc.; The image captured from this imaging means is converted into grayscale image data, and this converted grayscale image data is converted into 2
The image processing means includes a storage means for storing at least data regarding the outer diameter dimension of the electronic component, etc., and an image of the part imaged by the imaging means from the storage means. A calculation that predicts and calculates the area where a lead exists, detects an arbitrary lead only in that area along the scanning line of the imaging means, and calculates the center coordinates and inclination of the entire part based on the detected results. Provided is a component mounting apparatus characterized by having means.

[0019]

[Operation] The component mounting apparatus of the present invention configured as described above captures an electronic component having leads to be mounted on a board as an image, converts it into grayscale image data, and binarizes the converted data. When doing so, the area where the lead exists in the part imaging screen is predicted and calculated based on the stored data regarding the outside diameter of the part, and any lead is detected only in that area along the scanning line of the imaging means. Based on the detected results, the center coordinates and inclination of the entire component are calculated, and the position of the electronic component, etc. is corrected based on the calculated values.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In this embodiment, as shown in FIG.
C data receiving means 20, measurement window calculating means 21 for predicting the IC imaging area based on this data, IC imaging means 22 for actually imaging the electronic component, and detecting leads of the electronic component in the captured image. An IC lead detection means 23, an IC center/inclination calculation means 24 which calculates the center coordinates/inclination of the electronic component itself from the center of each detected lead, and an electronic component mounted on a printed circuit board based on the calculated center/inclination. The mounter controller 19 has a mounting correction data transmitting means 25 that calculates correction data for the mounter and sends it to the mounter controller 19, and the mounter controller 19 controls a suction head (not shown) based on this mounter controller 19. ,
The relative positions of electronic components and printed circuit boards are corrected.

In the device configured as described above, first, the IC data receiving means 20 communicates with the mounting machine controller 19 to take in external size data of the electronic component to be imaged and data on the number of recognized IC leads.

Next, the IC imaging means 22 images the electronic component suctioned by the suction head (not shown). This means that, for example, the video data on the IC lead is stored in an arbitrary storage means (not shown) as data on the sawtooth.

Next, based on this data, the measurement window calculation means 21 predicts the presence of electronic components and their leads in the electronic component imaging data, that is, the video data stored in the above-mentioned arbitrary storage means. Calculate the area of the part. Then, only for this area, the IC lead detection means 23 detects a predetermined number of leads (=
It efficiently and independently detects only the 4 leads of the electronic component (number of recognized IC leads), and furthermore, the IC center inclination calculation means 24 prevents recognition failure even if there is a large deviation in the rotational direction of the electronic component. Calculate the direction center coordinates. Thereafter, the mounting correction data transmitting means 25 calculates the amount of positional deviation of the electronic component and transmits the data to the mounting machine controller 19. Next, regarding the visual recognition positioning process in this example for mounting electronic components on a printed circuit board,
This will be explained using FIGS. 2 and 3.

First, IC external shape data is received (2-1
). This is about the electronic component that you are trying to recognize.
The external size data is received from the mounting machine controller as a recognition condition.

As shown in FIG. 3, the received data is as follows.
IC external size C1~C4, lead pitch C5, C
6. Number of lead pins, lead bending tolerance, pixel calibration value, number of leads, and number of recognized leads. Here, the number of leads to be recognized is the number of leads that are simultaneously checked when recognizing the leads of an electronic component.

Next, based on the received data, a measurement visual field D1 as shown in FIG. 4 is calculated. This measurement field of view D1 is an area indicating the approximate position within the camera field of view when an electronic component is imaged by a camera, and can be freely set based on the external size of the electronic component. Next, the electronic component is imaged (2-2). Image data captured by imaging is subjected to A/D conversion processing and then stored in an arbitrary storage means.

Next, a measurement window D28 for IC upper lead recognition as shown in FIG. 4 is calculated based on the received data. This window D28 is a rectangular area composed of four points D29 to D32. This window D28
A specific calculation example will be shown below regarding the coordinates of the four points D29 to D32. [Measurement window origin (D29: (X0, Y0)] X0
=255-(X1×r×α) Y0=240-(Y1×r×α) [Measurement window 1 point (D30: (X1, Y1)] X1
=255+(X1×r×α) Y1=240−(Y1×r×α) [Measurement window 2 points (D31: (X2, Y3)] X0
=255+(X1×r×α) Y0=240+(Y2×r×α) [Measurement window 3 points (D32: (X4, Y4)] X1
=255+(X1×r×α) Y1=240−(Y2×r×α) However, α/r is as follows: α: Calibration data (pixel calibration value) r: Window safety factor (1.0~ 2.0)...This shows the ratio of the window size to the IC size. X1: IC external size (C1 in Figure 3) Y1: IC
External size (C3 in Figure 3) X2: IC external size (C2 in Figure 3) Y2: IC
External size (C4 in Figure 3)

[0029] In this formula, the camera coordinate system is 512 x 480
It is said that That is, the coordinates (255, 240) indicate the camera center coordinates.

Next, video data is extracted from the top of this measurement window D28 along the scanning line of the camera (
2-4). If this scanning is continued, the area where the leads are located on the upper side of the IC will eventually be reached. The principle of detection is to calculate the center of each IC lead by detecting the left and right edges of the IC lead from changes in video data extracted along the scanning line. Note that a description of the lead edge detection method will be omitted.

When detecting IC leads, only the number of recognized IC leads described above are detected. Now, in FIG. 4, the results of recognition performed with the number of detected IC leads set to six are shown as a model (=scanning lines D6, D7). Scanning line D6 detects six leads on the top side of the IC from the left end, and scanning line D7 detects six leads from the right end. between the two, i.e. I
Regarding the leads near the center of the upper side of C, only a lead pitch check is performed. The centers of each of the six IC leads detected by scanning lines D6 and D7 are defined as lead centers D18 and D19 in FIG. 2, respectively. In addition, if the predetermined number of leads (=the number of recognized IC leads) cannot be detected, or if the lead is detected but the pitch is different from the data received in advance, it is treated as an IC defect (2 -5).

In this embodiment, the same process as above is also performed on the left side, bottom side, and right side of the electronic component (2-6 to 2-1).
1). Then, the lead centers detected by these recognition processes are designated as lead centers D20, D21, D22, D23, D2.
4, set as D25.

Next, from the lead centers D18 to D25 detected above, the center of gravity of the imaged electronic component (IC
The center G) and the slope (the average value of the IC slopes D26 and D27) are calculated (2-12). Therefore, the calculation method will be described below. (1) Calculation of straight lines D14 to D17 Since straight line D14 is a straight line passing through two points, lead centers D18 and D22, the coordinates of lead center D18: (x11, y11) and the coordinates of lead center D22: (x31, y31). , D14
:(X-x11)×(y31-y11)=(x31-x
11)×(Y-y11) Since the straight line D15 is a straight line passing through the two points of the lead centers D19 and D23, the coordinates of the lead center D19: (x12, y12) and the coordinates of the lead center D23: (x32, y32). D15
:(X-x12)×(y32-y12)=(x32-x
12)×(Y-y12) Since the straight line D16 is a straight line passing through the two points of the lead centers D20 and D25, the coordinates of the lead center D20: (x21, y21) and the coordinates of the lead center D25: (x42, y42). D16
:(X-x21)×(y42-y21)=(x42-x
21)×(Y-y21) Since the straight line D17 is a straight line passing through the two points of the lead centers D21 and D24, the coordinates of the lead center D21: (x22, y22) and the coordinates of the lead center D24: (x41, y41). D17
:(X-x22)×(y41-y22)=(x41-x
22)×(Y-y22) (2) Calculating the coordinates of the IC center G

[0034] The four straight lines obtained in (1) above (straight line D14~
D17) to each intersection point, point X1 (Xa, ya
), X2 (xb, yb), X3 (xc, yx), X
4 (xd, yd). At this time, the coordinates (x0, y0) of the IC center G can be calculated as the center of gravity of the above four points. That is, x0=(xa+xb+xc+xd)/4y0=(ya+
yb+yc+yd)/4 Also, the rotation angle of the IC can be calculated as follows. Value of IC slope D26: tan-1 [(Yd-Yb)/(
Xd-Xb)] Value of IC slope D27: tan-1[(Yc-Yd)/(
Xc-Xa)]

After measuring the IC center of gravity and inclination, calculate the distance from the center coordinates of the camera and send it to the mounting machine controller (
2-13). Additionally, if an abnormality is detected when detecting each side of the IC lead, an abnormality code is sent to the mounting machine controller (
2-14).

Finally, the IC center of gravity G and I detected above
C tilt (not shown) and camera center coordinates (255, 23
9) is sent to the mounting machine controller as a mounting correction amount (2-13). In this embodiment, only the case where an electronic component is imaged in one field of view has been described, but it is also applicable to the case where an IC is imaged in a divided field of view. Next, other embodiments will be described using the drawings.

FIGS. 5 to 9 are modeled illustrations of the case where an electronic component is imaged with a divided field of view. Each of them does not image the entire electronic component, but images the four corners of the electronic component separately. A predetermined number of leads at the four corners of the electronic component are detected in each field of view. For example, in FIGS. 6 to 9, scanning lines D2, D3, D6, D7, D
10, D11, D14, and D15. Detect the center coordinates of the determined IC leads (6 leads). This is illustrated by the lead centers D4 and D5 in Figure 6.
, lead centers D8 and D9 in FIG. 7, lead centers D12 and D13 in FIG. 8, and lead centers D16 and D17 in FIG. Thereafter, the entire image data is synthesized within the visual recognition controller to calculate the center coordinates of the electronic component. FIG. 10 shows this as a model. Then, the IC center gradient calculation means calculates the IC center G, which is the IC center position, and transmits the amount of offset from the position of the camera center D20 to the mounting machine controller as correction data.

[0038]

[Effects of the Invention] As described above, according to the present invention, when the suction head takes out the electronic component from the packaging case,
Even if the electronic component is tilted, direct visual recognition is possible without mechanical pre-alignment, thereby preventing lead damage due to pre-alignment operation. Moreover, by eliminating this pre-alignment process, the time required to mount electronic components onto a board can be shortened.

[Brief explanation of the drawing]

[Fig. 1] A schematic configuration diagram showing one embodiment of the present invention

FIG. 2 is a flowchart showing control of an embodiment of the present invention.

[Fig. 3] A diagram showing received data of an electronic component used in an embodiment of the present invention.

[Fig. 4] A diagram modeling a position correction method in an embodiment of the present invention.

FIG. 5 is a modeled diagram showing another embodiment of the present invention.

FIG. 6 is a modeled diagram showing another embodiment of the present invention.

[Figure 7]
Modeled diagram showing another embodiment of the invention

FIG. 8 is a modeled diagram showing another embodiment of the present invention.

FIG. 9 is a modeled diagram showing another embodiment of the present invention.

FIG. 10 is a diagram modeling a position correction method in another embodiment of the present invention.

[Figure 11] Schematic configuration diagram showing a conventional component mounting device

[Figure 1
2] Schematic configuration diagram showing a positioning stage in a conventional component mounting apparatus

[Figure 13] A diagram modeling the conventional position correction method for electronic components

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1...Electronic component, 4...Lead, 19...Mounter controller, 20...IC data receiving means, 21...Measurement window calculation means, 22...IC imaging means, 23...IC lead detection means, 24...IC center/inclination calculation means , 25... Mounting correction data transmission means.

Claims (1)

[Claims] 1. A component mounting apparatus having a means for visually confirming an electronic component or the like having a lead, comprising a photographing means for capturing an image of the electronic component or the like, and converting the image captured from the photographing means into grayscale image data. and an image processing means for binarizing the converted data, the image processing means storing at least data regarding the external dimensions of the electronic component, and a part image capturing screen by the imaging means from the storage means. Predicting and calculating the area where the inner and middle leads exist, detecting an arbitrary lead only in that area along the scanning line of the imaging means, and based on the detected result,
1. A component mounting apparatus comprising: arithmetic means for calculating center coordinates and inclination of the entire component.