JPH0340500A - Position aligning device - Google Patents

Abstract

PURPOSE:To improve the mounting of a component in positioning accuracy by a method wherein the positional deviation between an electronic component and a board is detected, and the intrinsic drive error of a device is corrected. CONSTITUTION:A board image sensing optical system 3 and a board position recognition section 5 are provided to a board 11 placed on an X-Y table, and a component image sensing optical system 4 and a component position recognition section 6 are provided to an electronic component 2 held by a mounting head 8. Positional deviation data Xb and Yb, and Xp, Yp, and thetap detected by the recognition sections 5 and 6 are sent to an offset memory 10. corrections X, Y, and theta are computed through the memory 10 basing on the data Xb and Xb, data Xp, Yp, and thetap, and data dx, dy, and dtheta of the table 7 and the head 8. The computed corrections X, Y, and theta are sent to a control 9 to correct the positional deviation between the table 7 and the head 8.

Description

[Detailed Description of the Invention] [Summary] Regarding an alignment device that transfers and positions electronic components to a predetermined location on a board, the present invention detects misalignment of both the electronic components and the board, and also makes adjustments due to drive errors specific to the device. The purpose is to improve the positioning accuracy of mounting by making it possible to perform the positioning, and the system has a board photographing optical system that photographs the pattern of the board, and uses the image taken by the board photographing optical system to detect the positional deviation of the board. a component position recognition section that has a board position recognition section that detects a terminal section of the electronic component; a component position recognition section that has a component photographing optical system that photographs a terminal section of the electronic component, and detects a positional shift of the terminal section using an image taken by the component photographing optical system; A correction value is calculated and stored based on the positional deviation data detected by the board position recognition unit, the positional deviation data detected by the component position recognition unit, and the drive error data of the mounting head and the X-Y table, and the correction value is The offset memory is configured to send the correction value to the control unit so that the driving of the mounting head and the XY table is corrected according to the value.

(Industrial Application Field) The present invention relates to a positioning device for positioning electronic components at predetermined locations on a board.

As the integration of electronic components such as ICs has progressed dramatically, miniaturization of packages forming these electronic components and increase in the number of bins have become important factors for high-density packaging.

Therefore, DIP type (Dual In-1ine Pac
As a new package to replace the PGA type (Pin Grid) shown in the perspective view of the package in Figure 7.
Array) is now applied.

In such an electronic component 2, the pitch P of the bins 2B through which signals are input/output is narrow, and since a large number of bins 2B are arranged, it is difficult to visually observe the arrangement of the bins 2B from directly above.

Therefore, when mounting the electronic component 2 on the board 11 such as a printed circuit board, it is necessary to automatically mount the electronic component 2 on the board 11 using image recognition technology.
Container 1 with electronic parts 2 set in it, and base material 11
A loading head 8 driven by a drive mechanism 8A is provided with an X-Y table 7 loaded with
It is formed by providing

Therefore, the electronic component 2 set in the container l is held by the mounting head 8, and the mounting head 8 is driven by the drive mechanism 8A, and the bin 2B of the electronic component 2 is placed at a predetermined location on the pattern lIA stretched on the board 11. Positioning and mounting are performed one after another.

Therefore, a positioning device is provided for such positioning, and when mounting the electronic components 2, a large number of bins 2B are used.
High precision is required to ensure accurate positioning.

[Conventional technology]

Conventionally, the configuration was as shown in the conventional explanatory diagram of FIG. 6. (al) and (bl) in Fig. 6 are block diagrams, (a2
) is a photographed configuration diagram of the board, and (b2) is a photographed configuration diagram of the electronic component.

As shown in (al) of FIG. 6, by controlling the head drive unit 22 by the control unit 21, the loading head 8 is driven to hold the electronic components 2 from the container 1 and load them onto the X-Y table 7. The configuration is not such that the electronic component 2 is positioned at a predetermined location on the board 11 and the electronic component 2 is mounted.

In this case, the mounting head 8 is usually a suction head that suctions the electronic component 2 with a nozzle at its tip by suctioning air.

Further, the table driving section 2 controlled by the control section 21
3 includes a board position detection unit 2 that compares the image of the board 11 photographed by the board photographing optical system 3 with reference image data Dl.
4 is connected, the board position detection unit 24 detects the positional deviation amount of the board 11, and the detected positional deviation amount determines the
It is formed so that the position of the Y table 7 can be adjusted.

Furthermore, as shown in (a2), the substrate photographing optical system 3 in this case is loaded on the XV table 7 by passing the irradiation light from the light source 3A through the condenser lens 3B, the light shielding mask 3C, and the projection lens 3D. The structure is such that the substrate 11 is irradiated, the reflected light is received by the CC03G through the imaging lens 3E and the shielding mask 3F, and a silhouette image of the pattern IIA stretched over the substrate 11 is photographed. (Such an optical system for photographing a board has already been disclosed in Patent No. 63-13.
The application has been filed under No. 4440. ) Therefore, the mounting head 8
While the electronic component 2 is being transferred from the container 1 to the board 11 by the drive of It was taken into consideration.

Moreover, such position adjustment can also be performed by configuring as shown in (bl).

In the case of (bl), when the electronic component 2 is held by the mounting head 8, it is photographed by the component photographing optical system 4, and the photographed image is compared with the reference image data D2 by the component position detection section 28, and the positional deviation is detected. The mounting head 8 is configured so that the position of the mounting head 8 can be adjusted by detecting the amount and notifying the head driving section 27.

Therefore, when mounting the electronic component 2 on the board 11 loaded on the The amount of deviation is detected, the mounting head 8 is adjusted according to the amount of positional deviation, and after the adjustment, the electronic component 2 is mounted at a predetermined location on the substrate 11 by driving the mounting head 8.

In addition, as shown in (b2), the component photographing optical system 4 in this case moves the pin 2B of the terminal portion 2A of the electronic component 2 attracted by the nozzle at the tip of the mounting head 8 to the laser generating element 4^. Irradiates from all directions with laser light,
The camera 4F is configured to take pictures.

In this case, the laser beam irradiation by the laser generating element 4^ is performed on the side surface of the pin 2B by the cylindrical lens 4B, the cylindrical lens 4C, and the cylindrical lens 4D.
The illuminated pin 2B passes through the filter 4E and passes through the camera 4F.
It is formed to be photographed by.

(Such an optical system for photographing parts has already been disclosed in Japanese Patent Laid-Open No. 63-275907.) Therefore, when the electronic component 2 is held, the image taken by the optical system for photographing parts 4 The amount of positional deviation is checked, and if a positional deviation is detected, the mounting head 8 is adjusted in the X and Y directions and the angle θ, and after the position adjustment, the electronic component 2 is transferred to the board 11. , implemented.

[Problems to be Solved by the Invention] However, in the configuration shown in (al) and (b2) of FIG. Even if the positional deviation of the board 11 is detected and the position is adjusted, if the electronic component 2 actually has a positional deviation, it may not be possible to mount it in the specified position, or conversely, the position of the electronic component 2 may be incorrect. Even if the deviation is adjusted, if there is a positional deviation in the substrate 11, it cannot be mounted in a predetermined position.

In particular, if there is a device-specific drive error in the drive of the X-Y table 7 and mounting head 8 due to misalignment of the mounting of the optical system 3 for photographing the board and the optical system 4 for photographing the parts,
Even if the electronic component 2 is operated to be transferred to a predetermined location on the board 11, the electronic component 2 may not be mounted at the predetermined location due to a driving error.

Therefore, even if the position of the board 11 or the electronic component 2 is adjusted based on a predetermined standard, there is a problem in that accurate positioning cannot be performed.

Therefore, it is an object of the present invention to improve the positioning accuracy of mounting by detecting the positional deviation of both the electronic component and the board and making adjustments based on drive errors specific to the device.

(Means for solving problems) FIG. 1 is a diagram explaining the principle of the present invention.

As shown in FIG. 1, a board position recognition unit 5 has a board photographing optical system 3 that photographs the pattern of the board 11, and detects a positional shift of the board based on the image taken by the board photographing optical system 3; A component position recognition unit 6 includes a component photographing optical system 4 that photographs the terminal portion 2A of the electronic component 2, and detects a positional shift of the terminal portion 2A using an image taken by the component photographing optical system 4; Positional deviation data X b , Y b detected by the recognition unit 5 and positional deviation data X 111y, + θ detected by the component position recognition unit 6
, and the drive error data d, , dy+dθ of the mounted head 8 and the X-Y table 7, the correction values X, Y,
an offset memory that calculates and stores θ and sends the correction values XY, θ to the control unit 9 so that the driving of the mounting head 8 and the X-Y table 7 is corrected according to the correction values X, Y, θ; 10.

With this configuration, the above-mentioned problem is solved.

(Function) That is, the board photographing optical system 3 and the board position recognition unit 5 are attached to the board 11 loaded on the X-Y table 7, and the mounting head
The electronic component 2 held by the electronic component 2 is equipped with an optical system 4 for photographing the component.
and a component position recognition unit 6 are respectively provided, and the positional deviation data X b, Y b and Xp + Yst + θ, detected by the board position recognition unit 5 and the component position recognition unit 6 are sent to the offset memory 10, and the offset In the memory 10, positional deviation data X b , Y b and X, IYpl
θ, and the drive error data d, , d, , dθ of the X-Y table 7 and the mounted head 8, the correction values X, Y
, θ are calculated, and the calculated correction values X, Y, θ are sent to the control unit 9.
is notified, and the positional deviation of both the XY table 7 and the mounting head 8 is adjusted.

Therefore, compared to the conventional positional deviation adjustment of either the substrate 11 or the electronic component 2, the accuracy of the adjustment is improved, and furthermore, the drive error data d, d, of the X-Y table 7 and the mounting head 8, By adding , dθ, more accurate transfer can be performed, and quality can be improved through reliable mounting.

〔Example〕

The present invention will be explained in detail below with reference to FIGS. 2 to 5.

FIG. 2 is a block diagram of an embodiment of the present invention, FIG. 3 is a flowchart of the present invention, and FIG. 4 is an explanatory diagram of pin position deviation recognition of the present invention. (a) is a camera arrangement diagram; (b
) is a density graph, (c) (d) is an explanatory diagram of totaling the number of pixels, (e) (f) is an explanatory diagram of pin arrangement, (g) (j
) is a plan view of the window, (h) is an explanatory diagram of counting the number of pixels in the window, (k) is a flowchart diagram, and FIG.
a2) is a plan view of the main part of the substrate, (b) is a concentration graph, (C
) is an explanatory diagram for counting the number of pixels, and (d) is a flowchart diagram. The same reference numerals indicate the same objects throughout the figures.

As shown in FIG. 2, the pin 2B of the electronic component 2 held by the mounting head 8 driven by the head drive unit 13 is photographed by the component photographing optical system 4, and the photographed image data DP is controlled by the CPU 6A. The information is sent to the component position recognition unit 6 which includes a ROM 6B and a RAM 6G.
Further, the board 11 loaded on the X-Y table 7 driven by the table drive section 12 is photographed by the board photographing optical system 3, and the photographed image data DB is sent to the CPU 5^.
The output is sent to the board position recognition section 5 which includes a ROM 5B and a 1'lAM 5c controlled by the component position recognition section 6.
Positional deviation data x, y, θ calculated by
, and the positional deviation data X b , Y b calculated by the substrate position recognition unit 5 are stored in recording areas E2 and E3 of the offset memory 10, respectively,
In addition, in the recording area E4 of the offset memory 10, the installation error of the board photographing optical system 3 and the component photographing optical system 4 and the driving error of the mounting bed 8 and the X-Y table 7 were measured. Error data D3 of d, , dθ is stored, and these positional deviation data X 11+ yp,
θ, and X, , Y, and driving error data d
, , d, , dθ are calculated in the recording area El, and the correction values X, Y, θ are
The configuration is such that the positions 311 of the mounting head 8 and the x-y table 7 are adjusted by sending the information to the control unit 9 and controlling the head drive unit 13 and table drive unit 12.

Further, the image data DP is inputted by the camera interface 6D, and the image data DP is stored in the frame memory section 6E after A/D conversion. In this case, the parts photographing optical system 4 drives the zoom mechanism 4J by the zoom controller 6F to increase or decrease the magnification of the photographed image, and
The moving table 4 is moved by the moving table controller 6G.
It is formed so that an enlarged image of a predetermined location can be obtained by moving the image data H, and the positional deviation data x is determined by the image data DP.
,, Y'l) + θ, is the hard calculation processor 6■
The result of the calculation is sent to the external interface 6.
J to the offset memory 10, and similarly,
The image data DB is inputted by the camera interface 5D, the image data DB is stored in the frame memory section 5E after A/D conversion, and the positional deviation data Xb, Yb is calculated by the hard calculation processor 5F from the image data DB. The result is configured to be sent to the offset memory 10 via the external interface 5G.

Therefore, when mounting a predetermined electronic component 2 on the board 11, as shown in FIG. Set the parts to be moved to the predetermined location in Step 4.

On the other hand, the x-y table 7 is moved so that the part of the board 11 on which the electronic component 2 is mounted is located in the board photographing optical system 3 according to the mounting data stored in the floppy disk 9A.

Next, the component photographing optical system 4 and the component position recognition unit 6 recognize the position of the electronic component 2, and the board photographing optical system 3 and the board position recognition unit 5 recognize the position of the board 11. be exposed.

The positional deviations resulting from the recognition of the positions of the electronic component 2 and the board 11 are sent to the offset memory 10, and the offset memory 10 calculates correction values X, Y, and θ.

The drive of the mounting head 8 and the X-Y table 7 is controlled by the calculated correction values x, y, and θ, and are driven to perform position adjustment, and component mounting is performed.

Further, when the mounting of the electronic component 2 is completed, the presence or absence of the mounting of the next electronic component 2 is confirmed based on the mounting data described above, and if it is present, the process is repeated, and if not, the process ends.

Therefore, when mounting the electronic component 2 at a predetermined location on the board 11, the positional deviation of the electronic component 2 is corrected by the correction values X, Y, and θ, and the electronic component 2 is mounted with accurate positioning.

In addition, the camera 4F of the optical system 4 for photographing parts in this case is
As shown in FIG. 4(a), a half mirror 4G is disposed on the terminal portion 2A of the electronic component 2 to be photographed, and is provided at a location A and a location B so as to be orthogonal to the half mirror 4G. The camera 4F installed at location B has a wide field of view and low magnification, and the camera 4F installed at location B has a narrow field of view and high magnification. By switching between ^ and B, It is possible to freely obtain an enlarged image of the entire terminal portion 2A or a portion thereof without providing the zoom mechanism 4J as described above.

Further, the position of the image data DP photographed by the component photographing optical system 4 is recognized by the component position recognition section 6 in the following manner.

First, the image data DP is as shown in (b) of the first diagram.
The number of pixels corresponding to predetermined densities 0 to 255 is counted to create a density histogram.

In this case, since the total number of pixels in the electronic component 2 is known from the design value, the area closest to that value is integrated from the brightest side of the density histogram, and the density t at that time is binarized. Slice level.

Therefore, with the density t as the boundary, those darker than the density t are 0
′, image data OP with density t as 1 ゛
A/D conversion is performed by digitizing the data, and after conversion, the data is stored in the frame memory 6E.

Next, based on the data stored in the frame memory 6E, the vertical projection distribution on the X axis and the horizontal projection distribution on the Y axis are calculated for the number of pixels of 1' as shown in (c) and (d). The intersection point P of the vertical projection distribution xl and the vertical projection distribution v2 is set as shown in (e) and (f), and scanning is performed in the X and Y directions using the intersection P as the origin. The first bin Pl, which is the pixel of l', is detected, and the distances al and bl from the intersection P to the first pin P1 are calculated.

By comparing the calculated magnitudes of al and bi, when at<bl, the slope is in the 10 direction shown in (e), and when al>biO, the slope is in the 1θ direction shown in (f). It is confirmed that the inclination angle θ in this case is (1
) and (2).

10θ-Tanal/b1...(1)-θ=Tan
b1/a1 ・ ・ ・ ・ ・(2) Furthermore, the first bin P1, the inclination angle θ, and the pin 2B obtained in this way
A window Wl centered on the pin 2B separated by the dotted line shown in (g) by the pitch L of the window Wl.

W2. By setting W3... and increasing the magnification of the camera 4F, each window Wl, W2. W3・
Enter the enlarged image of...

The number of pixels in the X-axis and V-axis directions in the window of the enlarged image is totaled, and the vertical projection distribution and horizontal projection distribution shown in (h) are created, and the diagonal line of the vertical projection distribution and horizontal projection distribution is The center of gravity XG where the areas Sl and S2 are divided into two
By calculating and YG, the center of gravity of the window -G is calculated.

Finally, as shown in (j), the centroids WGI, WG2 . Calculate the linear equations V+ and y2 that are closest to each other by the least squares method, and calculate y, and y2
Find a straight line y that divides the intersection point into thirds, and calculate the angle α at which the straight line y intersects the X axis.

In this case, calculate the coordinates XO, YO that are 1/2 of the diagonal line in the design value of the electronic component 2 on the straight line y, and
The positional deviation data X Gl+ 1>1 θ can be obtained by the following equations (3), (4), and (5).

χG, =XO-xν...(3) Y, =YO-Yk...(4) θ, =4
5-α (5) However, in this case, X k rYk + is a coordinate when the positional deviation is zero based on the design value, and is a value calculated in advance.

Therefore, the positional shift of the electronic component 2 can be recognized by the operation shown in (k).

First, a selection is made to select the initial imaging range by the camera 4F, a density histogram of the image data DP obtained by imaging is created, a slice level for binarization is set, and the binarization of the image data DP is executed. , the vertical and horizontal projection distributions of the number of pixels are used to search for the first pin P1, thereby calculating the inclination angle θ.

Next, a window circle corresponding to each pin is set, an enlarged image in the window is inputted, the enlarged image is binarized, and the center of gravity WG of each pin 211 is detected. By detecting the center of gravity WG of all the pins, the attitude of the electronic component 2 is recognized, and component positional deviation data Xp+Yp+θ is calculated.

Further, the position of the image data DB photographed by the board photographing optical system 3 is recognized by the component position recognition section 6 in the following manner.

First, there is a fifth plate at the location where the electronic component 2 of the board 1t is mounted.
As shown in FIG.
Manually as in a2).

In this image data DB, as shown in (b), the number of pixels corresponding to predetermined densities 0 to 255 is counted to create a density histogram.

In this case, since the area of the reference mark IIB is known from the design value, the number of pixels closest to that value is found by integrating from the brightest side of the histogram, and the density t' at that time is taken as the binarization slice level.

Therefore, A/D conversion is performed by binarizing the image data DB with the density t as a boundary, values darker than the density t' as O', and those lighter than the density t' as 1, and after conversion, the data is stored in the frame memory. Store in 5E.

Next, as shown in (c), the 1' pixel of the image data DB is aggregated on the X-axis and V-axis to create a vertical projection distribution and a horizontal projection distribution. The center of gravity WG' of the reference mark IIB is calculated by calculating the center of gravity XG' and YG' where the area Sll, 5122 shown by diagonal lines is divided into two.

Therefore, the positional deviation data X, , Y of the substrate 11 is the coordinate X when the positional deviation of the reference mark IIB is zero.

It can be obtained by the following formulas (6) and (7) based on Y,'.

×5=XG'Xm'...(6)'l b=
YG' Y w ' (7) Therefore, the positional shift of the substrate 11 can be recognized by the operation shown in (d).

First, the image data DB captured by the optical system 3 for photographing the board.
Create a density histogram, set the binarization slice level, and execute binarization of the image data DB.
The vertical and horizontal projection distribution of the number of pixels is used to detect the center of gravity WG' of the reference mark 11B.

Next, positional deviation data Xb+Yb is calculated from the detected coordinates XG' and YG'' between the centroid points.

〔Effect of the invention〕

As explained above, according to the present invention, when mounting the electronic component 2 at a predetermined location on the board 11, the positional deviation data X, ly, +θ of the electronic component 2 and the positional deviation data X of the board 11 are determined in advance. b, Y, and mounting.

Driving error data d, , d, , dθ is stored in the offset memory 10, and adjustment values X, Y, and θ for correcting these positional deviations can be easily retrieved.

By driving the mounting head 8 and the X-Y table 7 by Y and θ, positional deviation can be eliminated and reliable mounting can be performed.

Therefore, compared to the conventional configuration in which the positional deviation is corrected by either the positional deviation of the electronic component 2 or the positional deviation of the board 11, highly accurate positioning is possible. Data d , , d, , d
By adding θ, when a large number of devices are prepared, a unique adjustment value is created for each device, which prevents positional deviation due to the device, improving positioning accuracy and quality. The practical effect is significant.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the principle of the present invention. FIG. 2 is a block diagram of an embodiment of the present invention. FIG. 3 is a flowchart of the present invention. FIG.
) is the camera layout, (b) is the density graph, (c) is the density graph.
(d) is an explanatory diagram of counting the number of pixels, (e) and (f) is an explanatory diagram of pin arrangement, (g) (j) is a plan view of the window, h) is an explanatory diagram of counting the number of pixels in the window, ( k) is a flow chart diagram. FIG. 5 is an explanatory diagram of the recognition of positional deviation of the substrate according to the present invention, (a
l) (a2) is a plan view of the main part of the substrate, (b) is a density graph, and (C) is an explanatory diagram of counting the number of pixels. (d) is a flow chart diagram. FIG. 6 is a conventional explanatory diagram, in which (al) and (bl) are block diagrams, (a2) is a photographed configuration diagram of a board, and (b2) is a photographed configuration diagram of electronic components. FIG. 7 is a perspective view of the package. Figure 8 shows a perspective view of the onboard aircraft. In the figure, (2) is the container 3, and the board photographing optical system 5 is the board position recognition unit. 7 is the X-Y table. 9 is a control unit. 11 is the board. Reference numeral 13 indicates a head driving section. 2 is electronic parts. 4 is an optical system for photographing parts. 6 is a component position recognition unit. 8 is the installed head. 1O is an offset memory 12 which is a table drive unit. (l'1) Figure + (2) Number of pixels (various) 'Q'' Figure 5 C Sai-nori (Kanmei Sagaki's Momo 4 Tan's I π Place F Shiroken Ken O Explanatory Diagram No. 50 C Shi no 2) Conventional Explanatory Diagram No. 6 (f)) Conventional Explanatory Port '1 !-6 figure (t no 2) Conventional explanatory diagram 6 figure ('f/) l) 4 parts photograph / Nakamoto's conventional Akatsukiyo X figure Kotobuki 651 (t no 4)

Claims (1)

[Claims] An X loaded with an electronic component (2) set in a container (1) and a board (11) on which the electronic component (2) is mounted.
-Table drive unit (12) that drives the Y table (7)
, a head drive unit (13) that drives the mounting head (8) on which the electronic component (2) is held, and the table drive unit (
12) and a control section (9) that controls the drive of the head drive section (13), the mounting head (8) and the X-
A positioning device that positions the electronic component (2) at a predetermined location on the board (11) by driving with a Y table (7), the board photographing optical system photographing the pattern of the board (11). (3) and detects a positional shift of the board (11) using an image taken by the board photographing optical system (3); and a terminal part (2A) of the electronic component (2). a component position recognition unit (6) having a component photographing optical system (4) for photographing the component, and detecting a positional deviation of the terminal portion (2A) using an image taken by the component photographing optical system (4); The positional deviation data (X_b, Y_b) detected by the position recognition unit (5) and the positional deviation data (X_p, Y_p, θ) detected by the component position recognition unit (6)
_p) and drive error data (d_x, d_y, dθ) of the mounting head (8) and the X-Y table (7)
The correction values (X, Y, θ) are calculated and stored, and the mounting head (8) and the X
- an offset memory (10) for sending the correction values (X, Y, θ) to the control unit (9) so that the drive with the Y table (7) is corrected; Device.