JPS63229313A - Mounting part inspection apparatus - Google Patents

Abstract

PURPOSE:To accurately measure a shape without generating blooming and to shorten a measuring time, by arranging a plurality of TV cameras each using a two-dimensional CCD sensor so as to shift the same little by little and dividing an object to be inspected to pick up the images of the divided sections and applying synthesizing processing to said images. CONSTITUTION:Since four TV cameras are arranged so as to be positionally shifted little by little, if four cameras are synchronized, time sharing operation is obtained. When a signal selection circuit 6 successively changes over four image signals 1-4 on the basis of the addresses in a frame Y-direction, one synthetic image wherein effective light cut images are gathered is obtained. This image is processed by a real time height data detection circuit 7 and the height data of left and right images are detected and two detected left and right height data are synthesized by a synthesizer circuit 11. The output data of the circuit 11 is stored in a memory 13 through a direct memory access DMA circuit 12. The DMA circuit 12 and the memory 13 are connected to a CPU 14 through a system bus and controlled if necessary by the CPU 14.

Description

[Detailed Description of the Invention] [Summary] The present invention provides an apparatus for inspecting the mounting state of components by irradiating an object to be inspected such as a printed board on which components are mounted and detecting the reflected light. Multiple television (TV) cameras using dimensional CCD sensors are arranged slightly offset from each other to divide images of the object to be inspected and perform composite processing to improve processing speed and avoid the sensor blooming phenomenon. This is what I did.

[Industrial application field]

The present invention relates to an automatic inspection device for the mounting state of electronic components such as chip components on printed circuit boards and hybrid ICs, and more particularly to a device for inspecting mounted components that measures and inspects three-dimensional shapes using a light cutting method.

[Conventional technology]

Conventionally, these devices used galvano mirrors (vibrating mirrors).
There is also one that uses a line CCD sensor. Printed boards and electronic components mounted on them are made of various materials, and the light reflectance varies greatly depending on the material. In particular, on a board after components have been soldered, the ratio of the reflected light intensity reaches 200,000 times between the solder surface, where the reflected light intensity is the highest, and the black component, where the reflected light intensity is the lowest. On the other hand, the dynamic range of the above-mentioned CCD line sensor is about 600. Therefore, when the detection system is given a sensitivity that allows detection of black components, saturation of the CCD line sensor is unavoidable in solder parts with high light reflectance.

When the CCD line sensor becomes saturated, pixels that are not actually saturated around the saturated pixel also output saturation signals due to a phenomenon called "pluming." For this reason, there is a problem that the image of the optical section is deformed, the measured shape becomes inaccurate, and accurate inspection cannot be performed.

If a two-dimensional CCD sensor is used instead of a galvanometer mirror and a line CCD sensor, the two-dimensional CCD sensor currently on the market can be used.
CD sensors are mainly used in consumer video cameras.
Unlike line CCD sensors, it has a blooming suppression function. Therefore, the above-mentioned plumping problem is solved. However, simply using a two-dimensional COD camera creates a new problem in that the measurement time increases.

Here are some concrete, realistic numbers:

(a) Dimensions of measurement target (printed board): 200 fins x 2
00mm (b) Horizontal resolution: 0.1 vn (c) Vertical (height) resolution: 0.2 Tsuru (d) Measurement height range: 10f
The output signal of the i two-dimensional CCD is an NTSC signal (standard TV signal), and frame data is output at 1/30 seconds. The number of pixels of the CCD is 510 horizontally. A product with a length of about 490 mm has been commercialized, and 500 heights can be obtained per frame. Therefore, for measurement under the above conditions, 20010, 1 xi1500 x 20010.1 x
i/30=267 seconds are required. On the other hand, what is practically required is 60 seconds or less. Furthermore, since the two-dimensional CCD can measure only 500 pixels in the horizontal direction at one time, an XY stage is required to measure the entire temporary print surface, which has the disadvantage of making the device expensive and large.

[Problem that the invention seeks to solve]

As mentioned above, a blooming phenomenon occurs in inspection equipment that uses a galvanometer mirror and a line CCD sensor, and another problem with equipment that uses a two-dimensional CCD sensor that suppresses the blooming phenomenon is that it takes a long time to perform measurements. .

Therefore, an object of the present invention is to be able to measure an accurate shape without causing the blooming phenomenon, based on the concept of dividing and imaging an object to be inspected using a plurality of TV cameras using two-dimensional CCDs, and to be able to measure the shape accurately. An object of the present invention is to obtain a mounted component inspection device that reduces time.

[Means for solving problems]

The device of the present invention includes a light irradiation means, a plurality of TV cameras 5,
A selection means 6 and a real-time height information detection circuit 7 are provided.

The light irradiation means irradiates a slit-shaped light beam 3 onto an object 1 to be inspected (for example, a printed board) on which a component 2 is mounted.

A plurality of TV cameras 5 are used to capture images of reflected light 4 from an object to be inspected 1 that is irradiated with a light beam 3 .

Each TV camera 5 divides each portion in the slit direction (direction of arrow 9) and images each portion.

The outputs of the plurality of TV cameras 5 are supplied to a selection means 6,
The outputs from each TV camera 5 are sequentially switched and combined into one screen, and the output of the selection means 6 is used to detect the height information of the component 2 in real time by a real-time height information detection circuit 7.

[For production]

When a mounted component is inspected using the above-mentioned apparatus, the time for inspection is shortened according to the number of TV cameras.

〔Example〕

The configuration of a mounted component inspection apparatus as a first embodiment of the present invention is shown in FIG. 3, and a block diagram is shown in FIG. 4.

A light beam 3 made by slit-shaped light emitted from a semiconductor laser with a cylindrical lens is irradiated onto the printed board 1 perpendicularly. There are four TV cameras 5 on one side and a total of eight TV cameras on both sides using two-dimensional CCDs.

Fig. 3 is simplified and shows one TV camera 5 on each side, but as in Fig. 1, the positions have been shifted and four are placed on one side.
The tables will be placed one by one. The reason for arranging the TV cameras 5 on both sides is to eliminate shadows that cannot be detected. One CCD camera 5 can obtain an image with approximately 500 pixels horizontally and 480 pixels vertically, so if four cameras are used on one side and the light beam 3 is divided in the slit direction 9 to capture the image, the horizontal total of 2 in the direction
Reflected light 4 from an object to be inspected in an area of 000 pixels can be imaged in one frame time (1/30 second).

Two signal selection circuits 6 as selection means are provided, one for each group of four TV cameras on one side. The signal selection circuit 6 receives images 1, 2, 3 and 4 from the four F cameras as shown in FIG. 4, and sequentially switches them to obtain a composite image as shown in FIG. . The positions of the four TV cameras are shifted little by little, that is, the first
Since the arrangement is shifted in the vertical direction in the figure, as shown in images 1 to 4 in FIG. If four cameras are operating synchronously, it will be time-division operation, and the four image signals will be divided into frames.
By sequentially switching based on the Y-direction address, one composite image that collects effective light section images can be obtained.

This image is processed by the real-time height information detection circuit 7,
The height information of the left and right images is detected in real time. The detected left and right height information is combined by a combining circuit 11. In other words, the signal from the TV camera on the side that is in the shadow and the reflected light 4 cannot be detected satisfactorily is excluded,
Select the signal from the TV camera that provides a satisfactory reflected light.

The output data of the synthesis circuit 11 is directly stored in a memory 13 via a DMA (direct memory access) circuit 12. Further, the DMA control circuit 12 and memory 13 are connected to a central processing unit (CPU) 14 via a system bus, and are controlled by the CPU 14 as necessary.

A block diagram illustrating image composition according to the second embodiment of the present invention is shown in FIG. In this embodiment, the TV camera groups on either the left or right side of the first embodiment are used, and these TV cameras are rotated 90 degrees around the optical axis. Therefore, the image of light sectioning becomes vertically long. In this way, the scanning line of the TV camera 5 becomes perpendicular to the slit direction of the light beam 3 in the image. A composite image is obtained by the signal selection circuit 16. This results in
Compared to the first embodiment, the height information detection circuit 17 can be made simpler in some cases, which helps to simplify the hardware. The number of pixels of an image obtained by one TV camera differs in length and width, so depending on the application, the second embodiment may be advantageous, or the first embodiment may be advantageous. The second embodiment is of course applicable to the case where two TV camera groups, one on the left and one on the right, are used.

〔Effect of the invention〕

According to the present invention, since blooming does not occur, the shape can be accurately measured, and the increase in the number of processing circuits can be suppressed to a minimum, thereby realizing an improvement in measurement speed.

[Brief explanation of drawings]

FIG. 1 is a block diagram explaining the present invention, FIG. 2 is a block diagram explaining the composite image of the present invention, FIG. 3 is a block diagram of the first embodiment of the present invention, and FIG. 4 is a block diagram explaining the composite image of the present invention.
FIG. 5 is a block diagram of a second embodiment of the present invention. In the figure, l...Printed board, 2...Component, 3...Slit-shaped light beam, 4...Reflected light, 5...TV camera, 6
...Signal selection circuit, 7.Real-time height information detection circuit, 8.Stage, 9.Slit direction arrow, 11.Composition circuit, 12.DMA circuit, 13..・Memory, 14...CPU,
16... Signal selection circuit, 17... Real-time height information detection circuit. Figure 1 to explain the present invention Figure 2 to explain the composite image of the present invention Figure 2 Configuration diagram of the first embodiment Figure 3 Left image Right image Block diagram image of the first embodiment Image 2 Image 3 Image 4 Second
Example block diagram

Claims (1)

[Claims] 1. Light irradiation means for irradiating a slit-shaped light beam (3) onto an object to be inspected (1) on which a component (2) is mounted; Target to be inspected (1)
a plurality of television cameras (5) that receive the reflected light (4) divided in the slit direction (9); and a selection of sequentially switching in response to output signals from the plurality of television cameras (5). A mounted component inspection apparatus comprising: means (6); and a circuit (7) for receiving a signal from the selecting means (6) and detecting height information of the component (2) in real time. 2. The plurality of television cameras (5) are divided into two groups, arranged so as to face each other across the slit-shaped light beam (3), and the selection means ( 6) and a circuit for detecting height information (7), and outputs of the two circuits for detecting height information are selectively used. 3. The plurality of television cameras (5) are arranged such that the scanning line of the television camera (5) is perpendicular to the slit direction of the light beam. or the device according to paragraph 2.