JPH0330812B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for inspecting whether a leadless chip component is correctly mounted in a predetermined position and in a predetermined state when the chip component is mounted on a printed circuit board. The objective is to provide an apparatus that can automate processes and perform inspections accurately and at high speed.

Recently, with the miniaturization of television receivers,
Chip components without lead wires are often used as resistors and other components mounted on printed circuit boards. In addition, such chip components can be easily automated to be mounted on a printed circuit board, and the mounting device can be simplified, so they are being widely used in this respect as well.

However, when such chip components are mounted on a printed circuit board, it is necessary to inspect whether each chip component is correctly mounted in a predetermined position and in a predetermined condition after the equipment process is completed. , conventionally, inspection staff visually inspected
The installation status of each chip component was inspected, which resulted in extremely poor work efficiency.
Moreover, there was a problem that there were many inspection omissions and inspection errors, and accurate inspection was not possible.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an apparatus that can eliminate such conventional drawbacks, automate the inspection process, and perform inspection accurately and at high speed.

Therefore, in the present invention, illumination light is irradiated from diagonally above in a predetermined direction onto the printed circuit board on which the chip components are mounted, and the shadows formed by the chip components are photographed from another direction using a television camera. The photographed shadow is compared with a reference shadow position stored in advance, and when a discrepancy between the two is detected, it is determined that the chip component is installed incorrectly. It is.

EMBODIMENT OF THE INVENTION Hereinafter, the present invention will be described in detail with reference to the drawings showing one embodiment thereof.

Figure 1 shows its overall configuration. 1 is a conveyor that conveys a printed circuit board 2 on which chip parts are mounted to a predetermined inspection position; 3X, 3Y are conveyors that convey the printed circuit board 2 in the X-axis direction and Illumination device that emits illumination light from diagonally above in the axial direction, 4X,
4Y is a television camera that photographs the shadow formed on the printed circuit board 2 from the opposite sides of the illumination devices 3X and 3Y in the X-axis direction and Y-axis, and 5 is a television camera that uses the photographic output to determine the mounting state and the result thereof. This is a control unit that displays.

As shown in FIGS. 2 and 3, a large number of chip components 6 are mounted on the printed circuit board 2 by an automatic component device and transported to a predetermined inspection position by the conveyor 1. In the illustrated example, the mounting position of one of the chip parts 6 6' is erroneously deviated from the predetermined mounting position (broken line). When the printed circuit board 2 is positioned at a predetermined position, first, power is supplied from the control unit 5 to the illumination device 3X for the X-axis direction, and almost parallel illumination light is irradiated onto the printed circuit board 2 from diagonally upper left in the X-axis direction. . Then, this irradiation light causes dark shadows 7, 7' on the right side of the chip parts 6, 6'.
TV camera 4 from diagonally upper right in the X-axis direction at 7'.
Photograph by X. In the illustrated embodiment, in order to take more accurate pictures, the two television cameras 4X are used to take half the shots, but of course only one TV camera 4X may take the pictures.
In the following description, it will be assumed that the entire image was photographed using only one camera. FIG. 4 shows the photographed shadow image 8. Therefore, the positions of the shadows 7, 7' on the actual printed circuit board 2 obtained by this photographing, and the positions of the shadows that will serve as a reference when the chip component 6 is mounted at a predetermined correct mounting position. The controller 5 compares the values and automatically determines whether the mounting position is good or bad, and displays the results. A pattern 9 representing the reference shadow position in the illustrated embodiment is shown in FIG. Here, 10 represents the reference position of the shadow of each chip component 6.

FIG. 6 shows an example of a mounting state determination and display circuit in the control section 5. In the figure, reference numeral 11 denotes a synchronization board which generates synchronization reference signals such as horizontal and vertical synchronization signals, color carrier signals, and various clock signals in order to operate the entire system in the same synchronized state.

First, the video signal of the shadow image 8 obtained by photographing the shadows 7, 7' of the printed circuit board 2 on which the chip parts 6, 6' have been mounted as described above with the television camera 4 is
The signal processing circuit 12 converts the signal into a binary signal by slicing it at a constant level. On the other hand, a pattern 9 representing the reference shadow position 10 as shown in FIG. 5 is created in advance, and this pattern is stored in a magnetic sheet memory or
It is stored in advance in a pattern memory 13 such as an IC memory. Then, in synchronization with the photographing of the shadows 7, 7' of the printed circuit board 2 by the television camera 4, the pattern signal of the reference shadow position 10 is read out from the pattern memory 13, and the comparison circuit 14 compares the two.
This comparison operation corresponds to overlapping photographed shadows 7, 7' and reference shadow position 10 and detecting their coincidence as shown in FIG.
Therefore, in the comparison circuit 14, when there is a shadow that does not match the reference shadow position 10, such as the shadow 7' of the chip component 6', it is determined that the mounting position of the chip component 6' in the shadow 7' is incorrect. generates a judgment output.

Therefore, by using this determination output, when even one chip component 6' is installed in an incorrect mounting position, the display device 15 is driven to display a red lamp or the like by lighting up a red lamp.

Also, by using this judgment output, when the surface of the printed circuit board 2 is divided into, for example, 10 vertical x 10 horizontal sections, the shadow 7' of the chip component 6' that is incorrectly installed in any of the sections is detected. A counter 16 counts the number of detected objects in each section, and a character generating circuit 17 generates a numerical character pattern signal representing the number of detected objects in each section. At the same time, a pattern signal for displaying 10 vertical x 10 horizontal squares is stored in advance in the display pattern memory 18, and the pattern signal is read out from this, and is synthesized with the previous character pattern signal in the synthesis circuit 19. By supplying the chips to the CRT display device 20, as shown in FIG. Display. Therefore, the staff member looks at the display screen 23 and immediately searches for the chip part 6' that is not installed correctly.
You can perform tasks such as reinstalling the device correctly. In addition, if all the chip parts 6 are in the correct mounting state and the comparator circuit 14 does not generate a judgment output of incorrect mounting, the character generation circuit 17 generates a character pattern for displaying the display characters 24 as shown in FIG. It is sufficient to generate a signal.

In this way, by comparing the image 8 obtained by photographing the shadows 7, 7' of the chip parts 6, 6' on the printed circuit board 2 with the television camera 4X and the pattern 9 of the predetermined reference shadow position 10, If a chip component 6' is not correctly installed in a predetermined position, this can be immediately detected. Furthermore, since all such inspections can be performed electronically, inspections can be carried out very efficiently in a short period of time, and accurate inspections can be carried out without any oversights or errors.

In the above explanation, the inspection process using illumination and photography in the X-axis direction was explained, but when the chip component 6 is mounted in various directions as shown in the figure, not only the X-axis direction but also the Y-axis direction is used. Similar tests may be performed from all directions, and the quality of the wearing condition may be determined based on the overall results.

To do this, after completing the inspection in the X-axis direction as described above, power is supplied to the illumination device 3Y for the Y-axis direction to illuminate the top surface of the printed circuit board 2 from diagonally above in the Y-axis direction. , the shadow at that time may be photographed by the television camera 4Y.
In this way, when inspecting from both the X-axis direction and the Y-axis direction, when inspecting in the X-axis direction, only the chip parts arranged in the direction perpendicular to the X-axis direction are inspected, When inspecting in the Y-axis direction, it is sufficient to inspect only chip parts arranged in a direction perpendicular to the Y-axis direction. Furthermore, such test results may be printed out using the printer 25.

As detailed above, according to the inspection device of the present invention, all inspection processing can be performed electronically, so compared to conventional inspections that were conducted visually by inspection personnel, It is possible to fully automate the process of inspecting whether the chip components are properly mounted on a printed circuit board, and moreover, the inspection can be performed accurately, efficiently, and at high speed.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the overall configuration of a chip component mounting inspection device according to an embodiment of the present invention, Fig. 2 is a top view of the illumination/photographing portion of a printed circuit board of the same device, and Fig. 3 is a side view thereof. , FIG. 4 is a plan view showing a shadow image taken by the same device, FIG. 5 is a pattern diagram of the reference shadow position used in the same device, FIG. 6 is a block diagram of the judgment display part of the same device, and FIG. Plan views illustrating comparison operations in the same device, Figures 8 and 9.
The figure is a front view showing the display state of the device. 2... Printed circuit board, 3X, 3Y... Lighting device, 4X, 4Y... Television camera, 5... Control unit, 6, 6'... Chip parts, 7, 7'... Shading,
8... Photographed image, 9... Reference shadow position pattern,
10...Reference shadow position, 11...Synchronized board, 12...
... Signal processing circuit, 13 ... Reference shadow position pattern memory, 14 ... Comparison circuit, 15 ... Display device,
16...Counter, 17...Character generation circuit, 18
...Display pattern memory, 19...Synthesis circuit,
20... CRT display device, 21... Square pattern, 22, 24... Character pattern.

Claims (1)

[Claims] 1 means for irradiating illumination light from diagonally above in a predetermined direction onto a printed circuit board on which a plurality of chip components are mounted; and means for photographing shadows formed by the chip components from another diagonally above direction using a television camera; and a means for comparing the photographed shadow with a reference shadow position stored in advance and determining that the mounting state of the chip component is defective when a mismatch between the two is detected. A device for inspecting the placement of chip parts.