JPH0999547A - Automatic instruction device of recognition mark position and instruction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automate mark instruction on a printed board and a screen mask by coaxially arranging optical axes of a wide range photographing camera and a recognizing high magnification camera, switching these cameras as occasion demands, and photographing a recognition mark. SOLUTION: A recognizing high magnification camera 9 to be used for recognition correction is arranged such that its optical axis is coaxial to a mark instruction through a wide range photographing camera 8 for photographing wide ranges, a lenses 10, 11 and a half mirror 12. A camera switching device 16 turns on and off a marker irradiation device 13 by a control signal 18 coming from a recognition board 17 and switches between the wide range photographing camera 8 and the recognizing high magnification camera 9. Errors ΔX, ΔY between the center point of the wide range photographing camera 8 and the recognition mark are read by a CCD element. Coordinates Cx2 and Cy2 at a target camera position are calculated based on Cx2=Cx1+ΔX.T, Cy2=Cy1+ΔY.T, wherein Cx1 and Cy1 represent a present camera position and T represents a length of a printed board per picture element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic teaching device and a teaching method for a recognition mark position, and more particularly to a recognition camera of equipment for printing cream solder on a printed circuit board for mounting electronic parts.

[0002]

2. Description of the Related Art In recent years, with the miniaturization of electronic equipment, the lead pitch of a QFP (Quad Flat Package) in which electronic components, especially IC chips are connected to lead wires and wholly sealed with resin or ceramics has become narrower. The cream solder printing machine is required to support narrow pitch land printing.

FIG. 4 is a schematic block diagram of a conventional cream solder printing machine. In the configuration shown in FIG. 4, the stage 1 is an apparatus that sets the printed board 2 to a predetermined position and moves it to the screen mask 3. The recognition camera 4 is the printed circuit board 2
The recognition mark (not shown) provided on the screen mask 3 is photographed, and the recognition monitor 5 displays the image photographed by the recognition camera 4. The camera shaft 6 is a mechanism for moving the recognition camera 4 to an arbitrary position. The squeegee 7 fills the opening of the screen mask 3 with the cream solder and the printed circuit board 2
Is a device for printing.

Next, the operation of the cream solder printing machine having the above construction will be described. The operation of the cream solder printing machine is mainly
It is divided into an operation of aligning the printed circuit board 2 with the position of the screen mask 3 (plate alignment) and an operation of filling the opening of the screen mask 3 with cream solder (printing operation).

In the plate aligning operation, first, the printed board 2 is carried into the stage 1 and is calibrated. After that, the position of the recognition mark provided on the printed circuit board 2 is measured by the recognition camera 4 to obtain the center position of the printed circuit board 2. The stage 1 is moved so that this center position is aligned with the center position of the screen mask 3 measured by the recognition camera 4 in advance.

The printing operation is performed after the plate alignment is performed.
By moving the squeegee 7 at a preset speed, the cream solder is filled in the opening of the screen mask 3.

In order to cope with the narrow pitch QFP in the cream solder printing machine performing such an operation, it is required to reduce the error in the plate matching operation (deviation between the pattern of the screen mask 3 and the pattern of the printed board 2). To be done. In the cream solder printing machine having the configuration shown in FIG. 4, generally, means for increasing the magnification of the recognition camera 4 and increasing the resolution of the movement amount of the drive shaft of the stage 1 are adopted.

[0008]

However, in the cream solder printer having the configuration shown in FIG. 4, in order to correct the fixed position of the screen mask 3 and the fluctuation of the printed circuit board 2 at the time of setting, the screen mask 3 and the printed circuit board 2 are corrected. It is necessary for the recognition camera 4 to capture the position of the recognition mark provided on the. Therefore, it is necessary to teach the positions of the screen mask 3 and the recognition marks on the printed circuit board 2 in advance.

In the conventional teaching method, the operator sets the sample printed circuit board 2 on the stage 1 when teaching the marks on the printed circuit board 2, and cream solders the screen mask 3 when teaching the recognition marks on the screen mask 3. It is set in a printing machine and the recognition monitor 5 confirms the position where the recognition camera 4 is currently photographing.

At this time, if there is a difference between the recognition mark to be taught and the center of the image taken by the recognition camera 4, the current position of the recognition camera 4 is estimated from the recognition monitor 5, the camera axis 6 is operated, and recognition is performed. The mark is adjusted so as to be in the center of the recognition camera 4.

However, as the recognition camera 4 becomes higher in magnification as the accuracy of the cream solder printing machine becomes higher, the range that can be photographed becomes narrower and the pattern of the printed circuit board 2 and the screen mask 3 displayed on the recognition monitor 5. It is difficult to estimate the shooting position of the recognition camera 4 from the characteristics. Further, even if the positional relationship between the recognition camera 4 and the recognition mark is visually confirmed, it is quite difficult to capture the recognition mark within a field of view of several millimeters square unless a means for displaying the photographing position of the recognition camera 4 is used. It costs.

Further, when the operator tries to stop the camera shaft 6 at an arbitrary position, since the range which can be confirmed by the recognition monitor 5 is extremely narrow, an operation of overshooting and returning without noticing that the target position is approached. repeat.

Further, when the pattern on the printed board 2 or the mask screen 3 has a shape similar to the recognition mark, a position different from the original recognition mark may be taught.

The present invention solves and teaches the above conventional problems.
(Producing a program) An object of the present invention is to provide a teaching automatic device and a teaching method suitable for a recognition solder mark position suitable for a cream solder printing machine that can shorten the time and automate the work of an operator.

[0015]

In order to achieve the above object, the present invention is directed to a recognition mark position automatic teaching device which is used for a recognition correction and a camera for photographing a wide range when a mark is taught. The recognition board includes a recognition high-magnification camera, a marker irradiation device for confirming the current photographing positions of the wide-range photographing camera and the recognition high-magnification camera, and a half mirror for switching the wide-range photographing camera and the recognition high-magnification camera. And a recognition monitor for displaying the photographing output of the wide-range photographing camera and the recognition high-magnification camera as an image.

Further, in the teaching method of the recognition mark position, since the center point of the camera image on the screen display of the recognition monitor photographed by the wide-range photographing camera and the center position of the recognition mark are matched, an error from the center point is generated. ΔX, ΔY
Is read by the CCD pixel of the wide-range shooting camera, and then the coordinates Cx2, C to be moved by the wide-range shooting camera are read.
Find y2.

[0017]

[Formula 2] Cx2 = Cx1 + ΔX · T Cy2 = Cy1 + ΔY · T where Cx1 and Cy1 are the coordinates of the current wide-range shooting camera, and T is the conversion coefficient, which is CC of the wide-range shooting camera.
Length of printed circuit board per pixel of D pixel After moving the camera for wide-range shooting to the coordinates Cx2, Cy2 obtained next, switch to the high-magnification camera for recognition and switch from the screen display of the recognition monitor to camera coordinates The feature is that mark teaching is performed by capturing the position.

[0018]

According to the present invention, the optical axes of the wide-range photographing camera and the recognition high-magnification camera are coaxially arranged in the cream solder printing machine, and switching is performed at any time depending on the use of the both cameras, and an error in the mounting positions of both cameras is caused. Since the recognition mark can be photographed without considering the above, the mark teaching provided on the printed circuit board or the screen mask can be automated, and the time spent by the operator for creating the program can be significantly reduced.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing the structure of an automatic teaching device for the recognition mark position in one embodiment of the present invention, showing a recognition camera section of a cream solder printing machine.

In FIG. 1, reference numeral 8 denotes a camera for photographing a wide area for mark teaching (hereinafter referred to as a wide area photographing camera: CAM1).
And is composed of CCD pixels. Reference numeral 9 denotes a recognition high-magnification camera (CAM2) used for recognition correction so that the optical axis is coaxial with the wide-range photographing camera 8 via lenses 10 and 11 and a half mirror (MIRROR) 12. It is arranged. Reference numeral 13 is a marker irradiation device (MARKER), which is used to photograph the current position on the printed circuit board 2 or the screen mask 3 from the illumination device 15 through the lens 14 by the wide-range photographing camera 8 or the recognition high-magnification camera 9. It is used to visually confirm whether or not the operation is being performed. Reference numeral 16 denotes a camera switching device, which is connected to the wide-range photographing camera 8, the recognition high-magnification camera 9, the marker irradiation device 13 and the half mirror 12, and the marker irradiation device 13 is controlled by the control signal 18 from the recognition board 17. Marker irradiation is turned ON / OFF, the wide-range photographing camera 8 and the recognition high-magnification camera 9 are switched, that is, the half mirror 12 is rotated and the image output signal of the recognition monitor 19 is switched.

The operation of the present embodiment constructed as described above will be described with reference to FIGS.
This will be described with reference to the flowchart of.

FIG. 2 (1) is a perspective view showing a state of the wide-range photographing camera 8, the recognition high-magnification camera 9, etc. while teaching the printed circuit board 2, and FIGS. 2 (2) and 2 (3) respectively show the recognition monitor 19.
An example of the screen display of the above-mentioned wide-range photographing camera (CAM1) 8 and recognition high-magnification camera (CAM2) 9 is shown. First, in order to teach the recognition mark 20, the printed circuit board 2 is first carried in and set on the stage 1 shown in FIG. Therefore, the control signal 18 from the recognition board 17 is used for the wide-range shooting camera (C
Switch to AM1) 8 (S1). Recognition monitor at this time 1
The screen display 19a of 9 is illustrated in FIG. 2 (2). Here, the cross point of the cross mark on the recognition monitor 19 is the center point 8a of the shooting range of the current wide-range shooting camera (CAM1) 8. This also matches the marker irradiation point 13a of the marker irradiation device 13 (S2).

Next, in order to match the center position of the recognition mark 20 with the cross point (center point 8a), the cross point (center point) 8
Wide-angle shooting camera (CAM
1) It is possible to measure whether or not the recognition mark 20 registered in advance in the wide-range photographing camera (CAM1) 8 is photographed by reading with the CCD element 8 (S3). The difference between the center point 8a of the wide-range shooting camera (CAM1) 8 to be moved next and the recognition mark 20 in the field of view, that is, the coordinate Cx of the target camera position to be moved.
2, Cy2 is calculated by (Equation 3) (S4). This calculation is performed by the CPU built in the recognition board 17.

[0024]

[Expression 3] Cx2 = Cx1 + ΔX · T Cy2 = Cy1 + ΔY · T where Cx1 and Cy1 are the coordinates of the current wide-range shooting camera 8, and T is a conversion coefficient, and the wide-range shooting camera (C
AM 1) 8 CCD pixel length per pixel on the printed circuit board 2.

Next, the coordinates Cx2, C obtained in the above (Equation 3)
High magnification camera for recognition by adding error ΔX ・ T, ΔY ・ T to y2 and moving wide-range shooting camera (CAM1) 8 (S5)
Control signal 18 from recognition board 17 to (CAM2) 9
Is switched by the camera switching device 16 (S6).

Next, the control signal from the recognition board 17
Marker irradiation device 13 via camera switching device 16 by 18
Is operated to irradiate the marker on the printed circuit board 2 or the screen mask 3 (S7). Recognition monitor at this time
The screen display 19b of 19 is illustrated in FIG. In this case, the center of the recognition mark 20 and the center point 8a of the wide-range shooting camera (CAM1) 8 coincide with each other (S8).

If the marker illuminated on the printed board 2 or the screen mask 3 and the image displayed on the recognition monitor 19 (FIG. 2 (2)) are confirmed, the camera position is corrected if necessary. Then, mark recognition is performed (S9), and mark teaching is performed by capturing the camera coordinate position.

[0028]

As described above, according to the present invention, the optical axes of the wide-range photographing camera and the recognition high-magnification camera are coaxially arranged in the cream solder printing machine, and the cream solder printing machine can be switched at any time depending on the use of the both cameras. Since the recognition mark can be photographed without considering the error of the mounting positions of both cameras, the mark teaching provided on the printed circuit board and the screen mask can be automated, and the operator can spend a lot of time to create the program. It can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an automatic teaching mark position teaching apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a process at the time of teaching marks in FIG.

3 is a flowchart illustrating the operation of FIG.

FIG. 4 is a schematic configuration diagram of a conventional cream solder printing machine.

[Explanation of symbols]

1 ... Stage, 2 ... Printed circuit board, 3 ... Screen mask, 7 ... Squeegee, 8 ... Wide range camera
(CAM1), 9 ... High magnification camera for recognition (CAM2),
10, 11, 14 ... Lens, 12 ... Half mirror, 13 ... Marker irradiation device, 15 ... Illumination device, 16 ... Camera switching device, 17 ... Recognition board, 18 ... Control signal, 19
… Recognition monitor, 20… recognition mark.

Claims (2)

[Claims] 1. A camera which has a coaxial optical axis and which captures a wide range at the time of teaching a mark, and a recognition high-magnification camera used for recognition correction, and current photographing positions of the wide-range photography camera and the recognition high-magnification camera. A marker irradiating device for confirming the above, a camera switching device for rotating a half mirror for switching the wide-range shooting camera and the recognition high-magnification camera according to a control signal from the recognition board, the wide-range shooting camera and the recognition high-magnification camera An automatic teaching device for a recognition mark position, comprising: a recognition monitor that displays the imaged output of the image. 2. The errors ΔX and ΔY from the center point for the wide-range photographing are adjusted so that the center point of the camera image on the screen display of the recognition monitor photographed by the wide-range photographing camera coincides with the center position of the recognition mark. CCD of camera
The pixel is read, and then the coordinates Cx2, Cy2 to be moved by the wide range photographing camera are obtained. [Equation 1] Cx2 = Cx1 + ΔX · T Cy2 = Cy1 + ΔY · T where Cx1 and Cy1 are the coordinates of the current wide-range shooting camera, and T is the conversion coefficient, which is CC of the wide-range shooting camera.
Length of printed circuit board per pixel of D pixel After moving the camera for wide-range shooting to the coordinates Cx2, Cy2 obtained next, switch to the high-magnification camera for recognition and switch from the screen display of the recognition monitor to camera coordinates A teaching method of a recognition mark position, which is characterized by performing mark teaching by capturing a position.