JP3452201B2 - Component mounting equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component actual device for temporarily and automatically mounting electronic components and the like with high speed and high accuracy. 2. Description of the Related Art In recent years, the density of mounting electronic components (hereinafter abbreviated as IC) on a print base has been increasing. As for ICs, package components such as QFPs have been used more frequently than ever with the integration of circuits. As shown in FIG. 6, a component mounting apparatus (hereinafter, referred to as a component mounting apparatus)
In order to mount the IC 2 having the leads L adsorbed and fixed to the robot head 1 (abbreviated as a mounting machine) on the printed circuit board 3, it is necessary to measure the amount of displacement of the IC 2 with respect to the robot head 1. Conventionally, IC recognition camera 4
After capturing the image of the IC2, the image data is stored in the image memory in the visual recognition controller 5, and then all the image data is subjected to a binarization process. The center of gravity and the inclination of the binarized image were calculated. [0004] Similarly, the recognition of the printed circuit board 3 is performed after the board mark 6 on the printed circuit board 3 is imaged by the board recognition camera 7, and the image data is binarized through the visual recognition controller 5 to be recognized. are doing. Thereafter, based on the image data from the visual recognition controller 5, the misalignment between the IC 2 and the printed board 3 is relatively corrected via the mounting machine controller 8, and the alignment is performed.
Attach IC2 on top. FIG. 7 is a diagram showing a model of a result obtained by imaging an IC and performing a binarization process. When the optical system transmits the light, the image on the IC 2 is dark and the others are bright. In this figure, the measurement window W shows all the areas that can be imaged by the IC recognition camera 4. Now, the four corner points are defined as the measurement window origin W0, end point W1, and W
2, W3. Binary image data is extracted in parallel with the X axis starting from the origin W0 of the measurement window W.
This is sequentially performed in the Y-axis direction. This is indicated by the image data extraction lines L1 and L2 in FIG. Since the video data extraction line L1 does not scan on the binarized image, it always has a dark state, that is, only a value of 0, as shown in the scanning result R1 of FIG. On the other hand, in the case of the video data extraction line L2, since it scans on the lead L of the IC2, it has a saw-tooth shape as shown in the scanning result R2. Conventionally, the image data extraction line L2 scanned on the lead L of the IC2 is applied to all four sides of the IC2, thereby making the I2
The center position coordinates of C2 were detected. [0007] Next will be specifically described with reference to FIGS 8 to this method. As described above, the saw-tooth data can be obtained by the video data extraction line L2 shown in FIG. From the sawtooth waveform data, the center coordinates of one side of IC2 are calculated. FIG. 8 is a model diagram for explaining this. First, data obtained by the video data extraction line L2 is referred to as video data R2 in FIG. The result of binarizing this data with a certain binarization threshold is shown in the figure.
The result is as shown in FIG. From this result, it can be seen that the edges at both ends of each lead can be detected. The lead center is calculated from these two ends. As a result, the lead centers are detected by the number of leads. Next, if one side of the IC 2, that is, the center of the lead group is set as the center of all the lead portions, this point can be calculated as the center of gravity of each lead center. FIG. 8 shows a model of the result of processing this operation on all four sides of the IC. In FIG. 8, a video data extraction line L2 is provided above the lead of IC2, so that the middle point P of the lead is obtained.
1 is detected. By applying the video data extraction line L4 to the left part of the lead, the lead middle point P2 is detected. Similarly, by applying the video data extraction lines L6 and L8 to the lower part and the right part of the lead, the lead middle points P3 and P4 are detected. Next, these lead midpoints P1, P2,
A method of calculating the IC measurement center of gravity G, which is the position of the center of gravity of IC2, and the IC gradients θ1 and θ2 from P3 and P4 will be described. If the straight line formed by connecting the lead middle points P1 and P3 is a straight line A and the straight line B is formed by connecting the lead middle points P2 and P4, the intersection of these two straight lines is the IC measurement emphasis G. The inclination of these two straight lines in the X-axis and Y-axis directions is represented by an IC gradient θ.
1, θ2. The calculation formula is as follows. The coordinates of the lead point midpoints P1 to P4 are determined as follows. Lead midpoint P1: (xa, ya) Lead midpoint P2: (xb, yb) Lead midpoint P3: (xc, yc) Lead midpoint P4: (xd, yd) Equation of straight line A: ( x−xa) × (yc−ya) = (x
c−xa) × (y−ya) Equation of straight line B: (x−xb) × (yd−yb) =
(Xd−xb) × (y−yb) Coordinate of the IC measurement center of gravity G: x = (mb−lb) / (la−)
ma) y = (la × mb−lb × ma) / (la−ma) where la, lb, ma and mb are la = (ya−yc) / (xa−xc) lb = (xa × yc−xc) × ya) / (xa−xc) ma = (yb−yd) / (xb−xd) mb = (xb × yd−xd × yb) / (xb−xd) IC gradient θ1 value: θ1 = tan−1 [(Yd-yb)
/ (Xd-xb)] IC gradient θ2 value: θ2 = tan-1 [ (xc-xa)
/ (Yc-ya) ] Note that the final inclination of the electronic component is transmitted to the mounter controller 8 as an average value of the IC inclinations θ1 and θ2. An IC2 robot using the above means
While detecting the displacement with respect to the head 1, the substrate mark
6 from the position of the center of the camera.
Obtains the positional deviation of the printed circuit board 3 has been carried out the actual mounting on the printed circuit board 3 while <br/> correct these positional deviation. [0015] In recent years, IC leads and lead pitches have been increasing in density and diversification. Therefore, two problems as described below have arisen. First, it has become increasingly difficult to accurately recognize leads due to the increased density of IC leads. In the optical system that has been set in the past, the leads of the IC have been crushed, and it has become impossible to correctly image each of them. To solve this problem, it is conceivable to increase the camera resolution, but it is difficult because the optical system must be changed. Even if the magnification of the camera is simply increased, the viewing angle of the camera becomes small, so that it is impossible to capture the whole view of the IC. For this reason, the problem of accuracy in recognition of IC leads is increasing year by year. Although the video data is apparently continuous data, it is actually discontinuous, and the resolution of the object to be imaged is limited due to the density and optical magnification of the camera light receiving element. When the IC lead pitch is extremely small, the video data is actually discontinuous data. Therefore, if the lead detection is performed by binarization processing or the like, the lead pitch value will contain a large error. That is, in the case where the IC leads themselves and the pitch thereof are extremely small and have a size corresponding to only a few pixels of the camera light receiving element, the conventional image processing techniques such as binarization or difference have extremely large variations in the leads and the lead pitch. It means that it gets bigger. A second problem is diversification of IC shapes. In the conventional method, after all the ICs of various sizes are imaged by the camera 1, binarization processing is performed on the entire area of the imaged screen, and then the IC lead position is determined for the binarized image of the IC present in the window. Measure and use the coordinates to calculate IC
After measuring the coordinates of the center of gravity, the positional deviation of the IC with respect to the robot head was calculated. Therefore, the amount of calculation is large,
In particular, in the case of an electronic component having a large resin mold portion, there is a problem that the processing time is greatly burdened and the processing speed is reduced. For example, in the above-mentioned conventional method, since the start of the video data extraction line for detecting the center of each lead portion starts from the four corners of the measurement window, the lead portion cannot be detected depending on the video data extraction line . Eventually, useless image scanning occurs. This means that, especially when the external size of the IC mounted on one printed circuit board is various, the magnification and the viewing angle of the camera for IC recognition must be set to the maximum external size of the IC. In the conventional method, when an IC having a small external size is mounted, the ratio of the IC binarized image occupying the imaging screen, that is, the measurement window, becomes small, and useless calculation processing is increased. Further, when calculating the center of gravity of the IC, there is a possibility that noise may be taken in an area other than the parts, and there is a possibility that the position of the center of gravity may be erroneously measured. Therefore, the present invention reduces the recognition processing time.
It is another object of the present invention to provide a component mounting apparatus capable of improving the position detection accuracy . According to the present invention, there is provided a lead or lead
Has visual recognition means for visually recognizing parts with marks.
In the component mounting apparatus, the visual recognition means includes:
Imaging means for capturing an image of a part, and external dimensions of the part, etc.
Storage means for storing data relating to
To recognize the parts from the video data obtained by
Based on the data stored in the storage means,
The lead or the mark exists in the video data
Region calculating means for predicting and calculating a detection region to be calculated;
Based on the calculated video data of the detection area only,
Detecting means for detecting the position of the mark or the mark;
Calculation for calculating the position of the component based on the detection result
Means. According to the present invention, the parts stored in the storage means are
Based on the data on the external dimensions, etc., the area calculation means
Recognition processing of parts from video data obtained by imaging means
Before reading, read the parts in the video data,
Predicts and calculates the detection area where the mark exists.
Detecting means based on the video data of only the detected detection area
Detects the position of the lead or mark, and
The calculating means calculates the position of the component based on the output result. An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the component mounting apparatus according to the present embodiment includes an IC data receiving unit 11 for receiving an IC outer size from a mounting machine controller 10 and an IC data receiving unit 11 based on the data.
C: a recognition area calculating means 12 for predicting an imaging area; an IC imaging means 13 for actually imaging an IC; an image memory 14 for storing image data from the IC imaging means 13; IC lead detecting means 15 for detecting by data interpolation processing, IC center of gravity / inclination calculating means 16 for calculating the center of gravity / inclination of the IC itself from the center of each detected IC lead, and IC on the printed circuit board based on the center of gravity / inclination. The main control part is constituted by IC correction data transmitting means 17 for calculating correction data for mounting and transmitting the data to the mounting machine controller 10. In the present embodiment having the main control unit configured as described above, the IC picked up by the robot head is picked up by the IC pick-up means 13 in the mounting machine. This captured image means that it is stored in the image memory 14 as data R2 on the sawtooth as shown in FIG. After that, the external size data of the imaged IC 2 shown in FIG. Next, the imaging data of the IC based on this data by the recognition area calculating means 12, i.e. the image memory 1
Among the image data stored in the 4, IC 2 and the IC
The area of the portion where the lead L is predicted to exist is calculated. In the present embodiment, the image data stored in the image memory 14 is interpolated by the IC lead detection means 15 only in this area, so that the recognition error caused by the increase in the lead pitch can be prevented while the center of the IC 2 in the four directions is prevented. Calculate the coordinates. As a result, the IC leads L can be detected without waste and with high accuracy. Next, from the center coordinates of the four sides of the IC, the coordinates of the center of gravity of the IC 2 and the inclination thereof are calculated by the IC center of gravity / inclination calculating means 16 and, based on this, the amount of displacement of the electronic component to the robot head is calculated. Then, the IC 2 is transmitted to the mounter controller 10 to mount the IC 2 on the printing base with high accuracy. In order to mount the IC 2 on the printed circuit board in the mounting machine , a visual recognition positioning process is performed by a camera as an IC imaging means. Hereinafter, the processing will be described with reference to FIG. First, the external data of the IC 2 to be recognized is received from the mounter controller 10 as a recognition condition (4-1). As shown in FIG. 2, the data to be received are the IC outer shapes IC1 to IC4, which are the outer sizes of the IC2 having the leads L, and the lead pitches P1, P2.
2. Number of lead pins, lead bending tolerance, pixel calibration value,
The content is the number of IC leads. Next, an image of the IC is taken by a camera. The captured image data is transmitted to the main control unit, where the A / D
After performing the conversion process and stored immediately in the image memory 14. Thereafter, based on the values of the IC outer shapes IC1 to IC4 and the pixel calibration values received as well as the lead pitches P1 and P2 ,
Four corner points of the small measurement window Wi shown in FIG.
(M0, M1, M2, M3) is calculated (4-2). For example, the following formula is given as a specific calculation example. [Small measuring window origin M0 (XF 0, YF 0) ] XF 0 = 255- (X1 × γ × α / 2) YF 0 = 240- (Y1 × γ × α / 2) [ a small measurement window end point M 1 ( XF 1, YF 1)] XF 1 = 255+ (X1 × γ × α / 2) YF 1 = 240- (Y1 × γ × α / 2) ··· However, alpha, gamma, following for X1, Y1 Street α : Calibration data (pixel calibration value) γ : Window safety factor (1.0 to 2.0) This indicates the ratio of the window size to the IC size. X1: IC outline IC1 Y1: IC outline IC3 In this equation, the camera coordinate system is set to 512 × 480.
That is, the coordinates (255, 240) indicate the camera center coordinates. Next, the video data extraction line Li1 is sequentially moved and scanned from the upper portion of the small measurement window Wi toward the positive side in the Y-axis direction. When this scanning is continued, the scanning reaches the area where the lead L is located above the IC (= video data extraction line Li2) (4-3). At this point, detection of IC leads is started (4-3). Next, the video data interpolation processing for detecting the IC lead will be described. The video data to be interpolated is limited to only the area of the video data near the IC lead where the video level difference is large. That is, it means that data interpolation is performed for each IC lead. The following equation can be used as the interpolation equation. Real values: X0, X1, X2, X3... Xn and function values: f (X0), f (X1), f (X2), f (X
3) When f (Xn) is given, the n-th order polynomial passing through this (n + 1) point is given by: ## EQU2 ## Now, it is assumed that the X axis is the image data coordinates and the Y axis is the image level (= shade level). The video data is numerically analyzed in units of 1/10 pixel from the interpolation formula thus calculated. The data derived in this way can be applied as data of the IC lead and other areas which could not be captured originally due to the limitation of the resolution of the camera light receiving element. Therefore, this data is subjected to a binarization process,
Alternatively, by performing the difference processing, the left and right edges of the IC lead can be detected in 1/10 pixel units , that is, in subpixel units. FIG. 5 models this. For example, in FIG. 5, attention is focused on the middle IC lead. The width of this IC lead is the value of the video data itself shown in FIG. 5B, that is, the IC lead edge LE because the video data is not interpolated in the conventional method.
And RE ′, and the width is 3 pixels. But,
In this embodiment, since the video data are interpolated, IC indicated by LE' shown in FIG. 5 (b), RE' the FIGS. 5 (a)
The lead edges LE and RE become the same, and the width of the IC lead is detected more correctly. Therefore, the lead widths H1, H in FIG.
2 and H3 , the lead width is detected more correctly than H1 ', H2' and H3 ' in FIG. 5B. Thus, it is possible to detect the IC lead width with higher accuracy than before. The center of each IC lead is determined from the left and right edges of each IC lead and determined as the center of the IC lead. The distance between the centers , that is, the lead pitch LP shown in FIG.
1 and LP2 are also the lead pitches LP1 'and L1 in FIG.
The detection is more accurate than P2 '. By this processing, the midpoint Pi1 of the IC lead portion in FIG. 4 is calculated (4-3). Thereafter, a check is made by comparing the detected number of IC leads and the lead pitch with the received IC outer shape data shown in FIG. 2 (4-4). Thereafter, the leads on the left, lower, and right sides of the IC are sequentially detected (4-6, 4-8, 4-10). However, at this time, in the three sides of the IC, the area where the IC lead exists, that is, the areas B to D are also predicted in advance . That is, the coordinates of the four corners of each of the B area, the C area, and the D area in FIG. The calculation procedure is performed by the following equation, for example. [B area] B area 1 point B1 X = 255− (X1 × γ × α / 2 ) Y = 240− (Y1 × γ × α / 2 ) B area 2 points B2 X = 255− (X2 × (2- γ ) ×
α / 2) Y = 240− (Y1 × γ × α / 2) B area 3 points B3 X = 255− (X2 × (2- γ ) ×
α / 2) Y = 240 + (Y1 × γ × α / 2) B area 4 points B4 X = 255− (X1 × γ × α / 2) Y = 240 + (Y1 × γ × α / 2) [C area] C region 1 point C1 X = 255- (X1 × γ × α / 2) Y = 240 + (Y 2 × (2-γ) × α / 2) C region 2 points C2 X = 255+ (X1 × γ × α / 2) Y = 240 + ( Y2 × (2-γ ) × α / 2) C area 3 points C3 X = 255 + ( X1 × γ × α / 2) Y = 240 + (Y1 × γ × α / 2) C area 4 Point C4 X = 255− (X1 × γ × α / 2) Y = 240 + (Y1 × γ × α / 2) [D area] D area 1 point D1 X = 255 + ( X2 × (2-γ) ×
α / 2) Y = 240− (Y1 × γ × α / 2) D area 2 points D2 X = 255 + ( X1 × γ × α / 2) Y = 240− (Y1 × γ × α / 2) D area 3 Point D3 X = 255 + ( X1 × γ × α / 2) Y = 240 + (Y1 × γ × α / 2) D area 4 points D4 X = 255 + ( X2 × (2-γ) ×
α / 2) Y = 240 + (Y1 × γ × α / 2) where α, γ, X1, X2, Y1, and Y2 are as follows: α : calibration data (pixel calibration value) γ : window safety factor ( 1.0 to 2.0) This indicates the ratio of the window size to the IC size. X1: IC outline IC1 X2: IC outline IC2 Y1: IC outline IC3 Y2: IC outline IC4 For example, the upper left point of the window W in FIG.
For example, γ = 1 at two points B2 in the B region in the above equation.
And X = 255− (X1 × α / 2), Y = 240− (Y
1 × α / 2), which is given by:
In the X direction, in the negative direction (left direction in FIG. 4) in FIG.
2) × α, that is, half of the IC outline IC1
Yes, in the Y direction, a negative direction (Fig.
(Upward at 4) (Y1 / 2) × α, ie IC outer shape IC
It means half of three. And B1 and B2
Is calculated by the same equation, so that the value of γ is close to 2.
As the distance increases, the distance between B1 and B2 in the X direction increases.
From the equation, it can be seen that the B region has an increased γ value.
It becomes wider as it goes. The same applies to other areas. Accordingly
The positioning of the IC when capturing images with the camera.
If the degree is high, set the value of γ close to 1.
And Thus , the lead detection of each side of the IC is performed while calculating the B to D areas for the lead detection. In the past, scanning to extract video data in order from the upper end of the camera coordinate system and searching for IC leads was performed, but it is sufficient to start from the upper end of the small measurement window Wi. When the lead on the IC is searched, the number of lead pins and the lead pitch are checked. If both within the allowable range, seek the lead center position coordinate is calculated from the value IC upper lead group entire center, i.e. the leads midpoint Pi1 of FIG. Here, the leads on the left, lower and right sides of the IC are detected.
The details of the exit are as follows. First,
Three regions B, C, and D are calculated from the solid expression . Now, the four points constituting this area are defined as B areas B1 to B4, C areas C1 to C4, and D areas D1 to D4, respectively, as shown in FIG. Since the lead midpoints Pi2 to Pi4 are present in the above area, the lead search by the video data scanning is performed in areas B to D
Perform only the area. [0051] That is, to scan in parallel toward the electronic component center and B region 1 point B1 a line segment connecting the four points B 4 as a start. 3 points C region for C region C 3 and 4 points C 4
A line segment that connects, performs a read search as start the D area two points D 2 and 3-point D 3 also for the D area. The action of the above are performed by the IC lead detecting means 15 of FIG. 1.
The processing described above corresponds to 4-3 to 4-10 in FIG. Next, the lead portion midpoint Pi1~Pi4 detected by the action to calculate the captured IC2 of the center of gravity (IC measuring the center of gravity G) · gradient (IC gradient Shitaai1, the average value of θi2) (4 -12). The calculation method can be the same as in the conventional example. After the measurement of the center of gravity and the inclination of the IC, the distance from the center coordinates of the camera is calculated and transmitted to the mounter controller 10 (4-13). Also, if abnormality is detected when the IC leads each side detection, it transmits the abnormality code to the mounting machine controller 10 (4-14). As described in detail above, in the present embodiment, the IC lead can be detected in subpixel units.
It is possible to prevent problems such as poor lead recognition and errors when detecting IC leads, which are caused by the limit of camera resolution. Further, in order to visually recognize only the area where the lead required for detecting the position of the IC is imaged, the I
Even if noise is generated at or around C, the position of the IC can be detected while avoiding the noise , and the accuracy of position detection is improved. Also, since image processing for recognition is not performed on unnecessary portions on the IC , the position detection efficiency is improved and
It is also possible to speed up the C recognition process. Also, the recognition area calculation means uses the external shape data of the IC.
Data (data on the external dimensions of parts, etc.)
Of the IC image data captured by the camera
The detection area where the code exists is predicted and calculated.
When it becomes necessary to change the detection area due to the change of the product type
In any case, as long as the external shape data of the IC is stored,
Automatically predicts IC lead detection area according to IC
Therefore, it is easy to set the detection area according to the IC.
It becomes possible. In the above embodiment, only the method of detecting the position of an IC has been described. However, the present invention is also applicable to the recognition of a substrate mark printed for detecting the position of a printed circuit board. That is, the substrate marks include a round shape, a square shape, a triangular shape, and a cross shape. These are imaged with an ITV camera and then binarized to measure the position of the center of gravity. At this time, if the shape of the board mark is previously filed in a visual recognition device, the board mark can be obtained from the data. The area where the edge detection point exists can be predicted .
This makes it possible to set an efficient measurement window in advance, thereby improving the recognition processing speed. Furthermore, in this case, it does not perform a recognition process measurement for unnecessary portions, thereby also improving the accuracy of position detection becomes possible to avoid the influence of noise on and near the substrate mark. [0059] Further, for the video data interpolation processing embedding also more accurately recognizable and makes a mark outer edge when applied to a substrate mark recognition, whereby the center of gravity measurement accuracy of the substrate mark is improved. According to the present invention, the recognition processing time can be reduced.
In addition, the position detection accuracy can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram showing a main control unit according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram showing IC outer shape data applied in one embodiment of the present invention. FIG. 3 is a control flowchart applied in one embodiment of the present invention. FIG. 4 is a model diagram showing data applied in one embodiment of the present invention. FIG. 5 is a view for explaining data interpolation applied in one embodiment of the present invention. FIG. 6 is a schematic configuration diagram showing a hardware configuration of an embodiment of the present invention. [7] The electronic component picked-model diagram illustrating the binarization result. 8 is a diagram illustrating the center coordinate calculation of the electronic component from the binarization result shown in FIG. [Description of Signs] 10 Mounter controller 11 IC data receiving means 12 Recognition area calculating means 13 IC imaging means 14 Image memory 15 IC lead detecting means 16 IC gravity center / gradient calculating means 17 IC correction data transmitting means

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-64-21673 (JP, A) JP-A-2-143599 (JP, A) JP-A-2-291906 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H05K 13/04 B23P 21/00 305 G01B 11/24 G06F 15/62 405

Claims (1)

(57) Patent Claims 1. A lead or in the component mounting apparatus having a <br/> objective recognizing visually recognizing means viewing the part with a mark, the visual recognition means, said part of the image Imaging means for capturing the image data; storage means for storing data relating to the external dimensions of the component; and video data obtained by the imaging means.
Before recognizing the part from the storage means,
Wherein Re in the image data based on憶data
Prediction calculation of the detection area where the code or the mark exists
Area calculation means to perform, and only the detection area predicted and calculated
The lead or the mark based on the video data of
A detecting means for detecting the position, the component mounting apparatus characterized by having a calculating means for calculating the position of the component based on the detection result.