JPH0563338A - Screen printing method and equipment for circuit board - Google Patents

Abstract

PURPOSE:To reduce processing time necessary for screen printing for a circuit board. CONSTITUTION:The set position of a board 91 set on a board table 41 is detected by a CCD camera 51, and its position deviation quantity is obtained by a control part 61. A driving circuit group 71 which has received a control signal from the control part 61 drives each of the motors 81X, 81Y, 81theta, in response to the position deviation quantity of the board 91. Each of the frames 12X, 12Y, 12theta is moved by the driving force of each of the motors 81X, 81Y, 81theta. The position of a screen 21 which is driven and controlled by the frames is conformed to the set position of the board 91, while the board table 41 is moved toward the screen 21 side. Thereby the screen printing of the circuit board can be speeded up.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing method and apparatus for circuit boards. Specifically, it is intended to provide a screen printing method and apparatus for a circuit board, which enables higher-speed processing in screen printing in which the circuit board is positioned by image recognition using an electronic camera.

[0002]

2. Description of the Related Art As the degree of integration of circuits becomes higher, when a circuit is printed on a substrate using a screen, it is required to position the substrate with high accuracy. However, the substrate may not be set in the correct position depending on the finish of the substrate itself. Therefore, conventionally, a method has been used in which the substrate is correctly positioned by image recognition using an electronic camera and screen printing is performed.

FIG. 4 shows the configuration concept of such a conventional screen printing apparatus for circuit boards. In FIG. 4, reference numeral 41 denotes a substrate table on which a circuit is printed, for example, a ceramic substrate 91 is set and is sent to the screen 31 side. The substrate 91 is set on the surface of the substrate table 41. A stopper (not shown here) is provided on the surface of the substrate table 41, and the position where the substrate 91 is set is determined by this. When the substrate 91 is set on the substrate table 41, two or more marks having a predetermined shape provided on the surface of the substrate 91 are replaced with one C mark.
The field of view of the camera is set so that a CD (charge-coupled device) camera 51 can be used to grasp one mark, or one CCD camera can be used to grasp one mark each. Mark is CC
When the mark is grasped by the D camera 51, the position of the mark is read by the controller 61 and the position is recognized.

When the mark position is read, the controller 61
Calculates the deviation amount and the deviation angle θ in the X-axis and Y-axis directions between the read mark position and the correct mark position where the printing plate attached to the screen 31 and the substrate 91 are aligned in position. Recognize the amount of displacement. This amount of positional deviation is the amount of movement of the substrate table 41 for position correction of the substrate 91 so as to obtain positional alignment with the printing plate. When the movement amount of the substrate table 41 is calculated, the control unit 61 sends a control signal to the drive circuit group 71 which drives the motors 81X, 81Y, 81θ. Here, the motor 8
1X moves the XY-θ table 43 to which the substrate table 41 is attached in the X-axis direction (left-right direction in the drawing). Further, the motor 81Y moves the XY-θ table 43 in the Y-axis direction (direction perpendicular to the paper surface), and the motor 81θ rotates the XY-θ table 43.

Therefore, the drive circuit group 71 receives the control signal from the control unit 61 indicating the amount of movement of the substrate table 41 for correcting the position of the set substrate 91, and drives the motors 81X, 81Y, 81θ. Drive it. As a result, the XY-θ table 43 moves in a direction that corrects the displacement amount of the substrate 91 in each of the X-axis and Y-axis directions, and moves the table 43 in accordance with the deviation angle θ of the substrate 91. Rotate in the direction to correct.

To explain this concretely, for example, two marks are provided on the substrate 91, and the proper position of the mark is such that the printing plate attached to the screen 31 and the substrate 91 are aligned with each other. M1 and M2 shown in FIG.
Is set on the substrate table 41 (FIG. 4) and CC
It is assumed that the mark positions of the substrate 91 grasped by the D camera 51 are m1 and m2 shown in FIG. Then, looking at the mark position m1 of the set substrate 91,
It deviates from the proper mark position M1 by Δx in the X-axis direction and Δy in the Y-axis direction. Further, the intersection angle between the line segment M1M2 and the line segment m1m2 is θ, and therefore the deviation angle of the substrate 91 is θ.

FIG. 5B shows such a set state of the substrate 91. The substrate 91 fixed on the surface of the substrate table 41 by the respective stoppers 42a and 42b (for the sake of convenience of explanation, the distortion of the shape is shown). However, it is not shown in the proper position.
Therefore, by driving and controlling the XY-θ table 43 (FIG. 4), the substrate table 41 is moved in the X-axis direction.
The substrate table 41 is moved by -Δy in the Δx and Y-axis directions, and the substrate table 41 is rotated by an angle θ so that the line segment m1m2 in FIG. 5A matches the line segment M1M2.
As a result, as shown in FIG. 5C, the substrate table 41 moves from the original position indicated by the alternate long and short dash line to the position indicated by the solid line, and the position of the substrate 91 set on the substrate table 41 is corrected. Done.

In FIG. 4, when the position of the substrate 91 set on the substrate table 41 is corrected, the feed table 44 on which the XY-θ table 43 to which the substrate table 41 is attached is mounted on the guide rail. It is guided by 45 and moves below the screen 31, where the circuit is printed on the substrate 91.

As described above, in the conventional example shown in FIG. 4, the positional deviation amount of the set substrate 91 is read by image recognition using the CCD camera 51, and the positional deviation amount is X-. The Y-θ table 43 is controlled by being driven and corrected to obtain the positional alignment between the printing plate attached to the screen 31 and the substrate 91.

[0010]

According to the conventional example shown in FIG. 4, before the circuit printing on the substrate 91 is started, after the set position of the substrate 91 is grasped by the CCD camera 51, each motor is moved. It takes time to drive 81X, 81Y and 81θ to drive and control the XY-θ table 43 and time to move the feed table 44 to the screen 31 side. However, in addition to the substrate table 41, the feed table 44 has an XY-θ table 43 mounted with the motors 81X, 81Y, and 81θ mounted thereon, and the weight of the feed table 44 is large. Therefore, the moving speed of the feed table 44 is slowed down, and it takes time from the setting of the substrate 91 on the substrate table 41 to the start of printing, and there is a problem to be solved that the device is lacking in high speed. ..

Moreover, there is an unsolved problem that the feed table 44 is shaken and the printing accuracy is lowered due to the heavy weight of the feed table 44. In addition, there is a problem to be solved that wear of the traveling portion of the feed table 44 and the guide rail 45 is increased and the durability of the device is impaired.

The motors 81X, 81Y and 81θ mounted on the XY-θ table 43 are connected to the drive circuit group 71 by drive control lines. Therefore, printing on one substrate 91 is completed and the next substrate 9 is printed.
In order to perform printing on No. 1, it is necessary to return the feed table 44 to the original position once, remove the printed substrate 91 from the substrate table 41, and set the next substrate 91. That is, it is difficult to arrange a large number of substrate tables 41 on which the substrates 91 have already been set and to feed them sequentially to the screen 31 side. Therefore, a means for feeding a large number of substrate tables 41 sequentially to the screen 31 side was taken. , Each of three motors 81X, 8
It is necessary to use a large number of XY-θ tables 43 equipped with 1Y and 81θ, which complicates the entire apparatus and reduces costs.
There was also an unsolved problem of causing ups.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in light of these problems to be solved. Therefore, in the present invention, the position of the substrate table on which the substrate is set is not corrected, and the substrate table is moved to the screen side as it is when the substrate is set. By image recognition using a camera,
The amount of positional deviation of the set substrate was determined, and the screen was moved according to the amount of positional deviation so that it would match the position of the set substrate.

[0014]

By using such means, the working time required to correct the position of the substrate table on which the substrate is set is saved, and the weight of the feed table of the substrate table is reduced. High-speed movement is also possible, and screen printing with high processing speed has come to be realized.

Further, the deviation of the feed table is prevented, the printing accuracy is improved, and further, the wear of the traveling portion of the feed table and the guide rails of the feed table is reduced, and the durability of the apparatus is improved. ..

Further, it becomes possible to sequentially feed a large number of substrate tables to the screen side without returning the feed table moved to the screen side to the original position, and high workability can be obtained.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of an embodiment of the present invention will be described with reference to FIG. Here, FIG. 1 shows the configuration concept of the present embodiment,
Components corresponding to those in FIG. 4 are designated by the same reference numerals.

In FIG. 1, differences from the configuration of the conventional example shown in FIG. 4 will be described. In the conventional example of FIG. 4, an XY-θ table 43 for correcting the set position of the substrate 91 (FIG. 4) placed on the substrate table 41 is arranged. On the other hand, in the present embodiment, the XY-θ table 43 is not arranged and the substrate table 41 is placed on the feed table 4.
It is directly mounted on No. 4. That is, when the positional displacement amount of the substrate 91 is obtained by image recognition using the CCD camera 51, the position of the substrate table 41 is not corrected, and the substrate table 41 is screened in the state when the substrate 91 is set. Move to 21 side.

On the other hand, on the screen 21 side, while the substrate table 41 on which the substrate 91 is set is moved to the screen 21 side, the screen 21 is moved in the X-axis and Y-axis directions and rotated to rotate the substrate. A screen drive unit 11 is provided to obtain positional alignment between 91 and the printing plate attached to the screen 21.
The screen drive unit 11 includes a frame 12X for receiving the driving force of the motor 81X to move the screen 21 in the X-axis direction, and a frame 12X for receiving the driving force of the motor 81Y to move the screen 21 in the Y-axis direction. 12Y and a frame 12θ for rotating the screen 21 by receiving the driving force of the motor 81θ. Here, the configuration of the screen drive unit 11 and each motor 81 in the conventional example shown in FIG.
The configuration of the XY-θ table 43 driven by X, 81Y and 81θ is substantially the same.

FIG. 2 is a sectional view showing the structure of the screen drive unit 11. In FIG. 2, the frame 12X and the apparatus main body (not shown) support the connecting tools 14Xa and 14Xb provided on the frame 12X by the respective support tools 13Xa and 13Xb fixedly attached to the apparatus main body. As a result, the frame 12X is coupled so as to be movable in the X-axis direction. Further, the frame 12X and the frame 12Y are connected to each other by the support tools 13Ya and 13Yb fixedly attached to the frame 12X, and the connection tools 14Ya and 14Y provided on the frame 12Y.
The frames 12Y are coupled in a movable state in the Y-axis direction by supporting b respectively. Further, the frame 12Y and the frame 12θ are each a supporting member 1 having a planar arc shape fixedly attached to the frame 12Y.
By supporting the respective couplers 14θa and 14θb provided on the frame 12θ by 3θa and 13θb,
A frame 12θ is rotatably connected, and a screen frame 22 on which a screen 21 is stretched is fixedly connected to the frame 12θ by fixing members 15a and 15b.

The operation of drive control of the screen 21 by the screen drive unit 11 thus constructed will be described. In FIG. 1, when the CCD camera 51 grasps the set position of the substrate 91, the control unit 61 recognizes the position of the substrate 91 by calculating the positional deviation amount of the set substrate 91. When the displacement amount of the substrate 91 is calculated,
The controller 61 sends a control signal to the drive circuit group 71 that drives the motors 81X, 81Y, 81θ. Therefore, the motors 81X, 81 that receive the output from the drive circuit group 71
By the driving force of Y, 81θ, each frame 12X, 12Y, 12θ is moved according to the displacement amount of the substrate 91. As a result, the screen 21 stretched on the screen frame 22 connected to the frame 12θ moves, and the positional alignment between the screen 21 having the printing plate attached and the substrate 91 is obtained.

That is, as shown in FIG. 3 (a), the substrates 91 fixed by the stoppers 42a and 42b on the surface of the substrate table 41 are set so as to be displaced, and therefore the setting position of the substrate 91 and the screen are set. Assuming that the position of the frame 22 is deviated by Δx in the X-axis direction and Δy in the Y-axis direction and has an angular difference θ, FIG.
As shown in (b), the screen frame 22 is moved by Δx in the X-axis direction and Δy in the Y-axis direction from the original position indicated by the alternate long and short dash line, and the angular difference between the substrate 91 and the screen frame 22 is eliminated. Thus, the screen frame 22 is rotated by the angle difference θ. As a result, the printing plate attached to the screen 21 and the substrate 91 are in positional alignment.

As described above, according to the present invention, the positional alignment between the printing plate attached to the screen 21 and the substrate 91 is obtained by driving and controlling the screen frame 22, and
The control operation is performed while the substrate table 41 (FIG. 1) moves to the screen 21 side.

Since the drive control line is not connected to the substrate table 41 side, it is not necessary to return the substrate table 41 to its original position when the circuit printing on one substrate 91 is completed. Therefore, it is possible to sequentially send a large number of substrate tables 41 on which the substrates 91 are set to the screen 21 side.

[0025]

As is apparent from the above description, according to the present invention, the position of the substrate table is corrected by the positional alignment between the substrate set on the substrate table and the printing plate attached to the screen. Instead, the substrate table is obtained by driving and controlling the screen frame while moving to the screen side, so that the processing time can be shortened by the time required when the position of the substrate table is corrected. Since the weight of the feed table having only the table mounted thereon is remarkably reduced as compared with the conventional one, and the moving speed of the feed table can be further increased, high-speed processing is realized when a circuit is printed on the substrate.

Further, as a result of reducing the weight applied to the feed table of the substrate table, deviation of the feed table is prevented and printing accuracy is improved, and wear of the traveling portion of the feed table and the guide rails on which the feed table moves. And the durability of the device is significantly improved.

Further, since the drive control line is not connected to the substrate table side, when the circuit printing on one substrate is completed, it is not necessary to return the substrate table to the original position, and the substrate is set. If a structure in which a large number of substrate tables are placed and sequentially fed to the screen side is used, it is possible to perform screen printing on a circuit board with a shorter working time. Therefore, the effect of the present invention is extremely large.

[Brief description of drawings]

FIG. 1 is a configuration conceptual diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the screen driving unit shown in FIG.

FIG. 3 is an operation explanatory diagram for explaining the operation of the screen drive unit shown in FIG.

FIG. 4 is a structural conceptual diagram showing a structure of a conventional example.

5 is an operation explanatory diagram for explaining the operation of the XY-θ table shown in FIG. 4. FIG.

[Explanation of symbols]

11 screen drive unit 12X, 12Y, 12θ frame 13Xa, 13Xb, 13Ya, 13Yb, 13θa,
13θb support tool 14Xa, 14Xb, 14Ya, 14Yb, 14θa,
14θb Connecting tool 15a, 15b Fixing tool 21 Screen 22 Screen frame 31 Screen 41 Substrate table 42a, 42b Stopper 43 XY-θ table 44 Feeding table 45 Guide rail 51 CCD camera 61 Control section 71 Drive circuit group 81X, 81Y, 81θ motor 91 substrate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H05K 13/04 P 8509-4E

Claims (2)

[Claims] 1. A position recognizing unit recognizes a positional deviation amount between a substrate (91) set on a substrate table unit (41) and a screen unit (21) for printing a circuit on the substrate (51, 61), moving the substrate for which the positional displacement amount is recognized by the position recognizing unit to the screen unit side, and adjusting the positional displacement amount to the substrate set on the substrate table unit while moving to the screen unit side. Correspondingly, the screen means is driven so that the position of the screen means coincides with the position of the substrate (12X, 12).
Y, 12θ, 81X, 81Y, 81θ, 71) Screen printing method for circuit board. 2. A substrate table means (41) for setting a substrate (91) and moving it to a screen means (21) side for printing a circuit on the substrate, and the substrate table means set to the substrate table means. Position recognizing means (51, 61) for recognizing the positional deviation amount between the substrate and the screen means, and the positional deviation amount during the movement of the substrate set on the substrate table means to the screen means side. Correspondingly, driving means (1) for driving the screen means to match the position of the screen means with the position of the substrate.
2X, 12Y, 12θ, 81X, 81Y, 81θ, 7
1) A screen printing device for a circuit board, which comprises: