JPH02212706A - Inspector for packaged printed circuit board - Google Patents

Abstract

PURPOSE:To enable measurement at points of a packed printed circuit board on the same conditions by varying respective angles of irradiation of a beam spot with respect to the printed circuit board. CONSTITUTION:An inspector for a packaged printed circuit board is provided with a plurality of beam spot generation means so arranged that a printed circuit board 10 is moved relative to the rotation of a rotor to be positioned on almost the same circumference on the center of the rotation of the rotor and a beam spot 11 is made to irradiate the printed circuit board 10 to scan it 10 sequentially and a plurality of photoelectric conversion means 2, 4, 6 and 8 which receives reflected light from the circuit board 10 to output a value corresponding to energy received. Information from multiple angles can be obtained by varying respective angles of irradiation of the beam spot 11 to the circuit board 10. Thus, as the plurality of photoelectric conversion elements 2, 4, 6 and 8 for receiving the reflected light of the beam spot 11 are arranged in perimeter of the beam spot 11, the reflected light can be received corresponding to a change in the reflected light which may occur to a certain extent depending on a direction of a soldered surface, thereby enabling a highly accurate inspection.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an inspection device for mounted printed circuit boards, and in particular uses a narrow beam spot to detect misalignment of mounted components, solder defects, solder bridges, etc. It is intended to be inspected.

Conventional technologyAs a device for inspecting conventionally mounted printed circuit boards for component deviations, missing parts, solder defects, solder bridges, etc.
There is a method using multi-slit light and a camera.

This will be explained below with reference to the drawings. In Figure 4, 5
5.66 is an irradiation device that irradiates each slit light,
64 is a camera, and 57 is a mounted printed circuit board. By irradiating two slit lights onto the mounted printed circuit board 67 from diagonally above so that their respective optical axes are perpendicular to each other and observing it from above with the camera 64, the height of the mounted component can be measured using the principle of triangulation. At this time, x, y3 /
You can know the position of parts in the \-7 direction.

Problems to be Solved by the Invention However, with the above configuration, although it is possible to measure the position of the mounted components before soldering, it is difficult to accurately inspect the solder surface after the soldering process. This is because the solder surface is close to the boundary surface, so depending on the orientation of the solder surface and the position of the camera, the reflected light may be too strong and the camera may become saturated, or conversely, the reflected light may be too weak to be detected. 3. Means for Solving the Problem The mounted printed circuit board inspection device of the present invention includes a rotating body that is rotationally driven and a printed circuit board to be inspected relative to the rotation. and a means for irradiating a beam spot onto the printed circuit board at substantially the same circumference around the center of rotation of the rotating body, and the beam spots are sequentially arranged as the rotating body rotates. a plurality of beam spot generating means disposed on the rotating body so as to scan the printed circuit board; and a plurality of beam spot generating means disposed on the rotating body radially centering on each of the beam spots to receive reflected light from the print co-forming. 7. Equipped with a plurality of photoelectric conversion means that output an output corresponding to the light receiving device and an amount corresponding to the received light energy, and It is characterized by the ability to obtain information from multiple angles by changing the image.

Effect According to the above configuration (C), a plurality of photoelectric conversion elements that receive the reflected light from the beam spot are arranged around the beam spot, so even if the reflected light changes to some extent depending on the orientation of the solder, the reflected light will be reflected accordingly. A plurality of photoelectric conversion elements that can receive light and are arranged around the beam spot (such as a steeply sloped solder surface that cannot receive light even if The reflected light can be received by either system.

As a result, implemented pudding!・It is possible to reproduce the irregularities of the board extremely accurately, enabling highly accurate inspection.

Embodiment 6 Beno Below, a mounted printed circuit board automatic inspection apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a unit inspection device in which a beam spot projecting optical system and a light receiving optical system group are integrated. 1 is a beam spot projection optical system using, for example, a laser; 2, 4, and 6.8 are devices for receiving reflected light from the reflecting surface of the beam spot and obtaining information on the height and brightness of the reflecting surface; It is a photoelectric conversion element such as a semiconductor device detection element T- (hereinafter referred to as PSD). This PSD has a predetermined length L2, and outputs from multiple output terminals change relatively depending on the irradiation position of the beat spot.
It is also possible to use an OD line sensor or the like.

3.6.7.9 is a lens or lens group for respectively focusing the reflected beam spot from the mounted printed circuit board onto the photoelectric conversion element 2.4.6.8 in order to perform triangulation. . These photoelectric conversion elements and lenses are
They are arranged around the optical axis of the beam spots 116, and in this embodiment, four sets are arranged at equal intervals (C) on the same circumference centered on the beam spot.

The present mounted printed circuit board inspection apparatus has five unit inspection apparatuses in which the optical system group shown in FIG. 1 is integrated. One beam spot 11 is irradiated almost perpendicularly to the mounted printed circuit board 10, and the remaining four beam spots 11 are irradiated at a certain angle to the mounted printed circuit board 1o. It is configured to irradiate from four different directions.

FIG. 2 is a perspective view of the entire inspection device. 13°14.
Reference numerals 15, 16, and 17 are one unit inspection device in which the optical system group shown in FIG. 1 is integrated.

13 irradiates the beam spot 11 almost perpendicularly to the mounted printed circuit board 10; 16 irradiates the mounted printed circuit board 10 from the direction of the y-axis at a certain angle (for example, at a 45 degree angle to the mounted printed circuit board 11). 16 directs the beam spot 11 to the mounted printed circuit board 10,
The beam spot 17 is irradiated from one direction of the X axis at a certain angle (for example, an angle of 46 degrees with respect to the mounted printed circuit board 10), and the beam spot 17 is irradiated at a certain angle (
For example, at an angle of 46 degrees with respect to the mounted printed circuit board)
It is irradiated from one direction of the axis.

Reference numeral 12 denotes a rotating disk that is driven to rotate at a nearly constant speed by a drive source (not shown) such as a motor.

The unit inspection device 13, 14, 16, 16, 17 detects the beam spot sequentially on the mounted printed circuit board 10 as the rotating disk 12 rotates at equal intervals on the same circumference with respect to the center of the rotating disk 12. arranged to scan. Therefore, the mounted printed circuit board 10 is shown in FIG.
By sequentially moving in the y direction of the 7rz coordinate system, it becomes possible to p-scan the entire mounted printed circuit board 10 with the beam spot.

Reference numeral 18 indicates a trajectory of the printed circuit board 10 currently being scanned by the unit inspection device 13 in a stationary state, and 22 indicates a trajectory of the printed circuit board 10 in the stationary state being scanned by the unit inspection device 17 following the unit inspection device 13. , 21 indicates the trajectory scanned by the unit inspection device 16, and 2
Q indicates the locus scanned by the unit inspection device 16, and 1
Reference numeral 9 indicates a locus scanned by the unit inspection device 14.

In Fig. 2, unit inspection device i3, 14.16°1
When the scanning of 6.17 is completed, the mounted printed circuit board 10 is intermittently moved by 1 pitch 1 in the y-axis direction, and the movement is completed before the next unit inspection device 13 starts scanning, thereby eliminating waste. The inspection can be completed in the minimum amount of time. Note that 23 is a unit inspection device 13 before intermittent driving.
It shows the trajectory scanned by.

FIG. 3 shows an electric circuit of this device for obtaining height information and brightness information by calculating two current outputs whose values change relatively depending on the irradiation position from the photoelectric conversion element. 2
Height information is obtained from the two page 9 current outputs of the 4Fi photoelectric conversion element 2 through the divider 52, and
This is a height and brightness information detection circuit that obtains brightness information from the sum of the two current outputs through an operational amplifier 63.

26.26.27 is also the height and brightness information detection circuit 24
This is a detection circuit similar to that of , and is connected to the photoelectric conversion element 4.6.8. In this case, since four photoelectric conversion elements are used, four pieces of height and brightness information are output for one light spot.

28 is a height information selection circuit that obtains one piece of height information from the four pieces of height information of the unit inspection device 13. For example, the selection method is to remove the maximum level and the minimum level among the four pieces and select the remaining two pieces of height information. There is a method of taking the average. 29, like 28, is a brightness information selection circuit that obtains one brightness information from four pieces of brightness information.As a selection method, for example, there is a method of taking the maximum level among the four pieces of brightness information. The above constitutes the brightness/height information detection circuit 30 of the unit inspection device 13. 31°3
2.33.34 are unit inspection devices 14゜16.1 respectively
The brightness/height information detection circuit 6.17 has the same configuration as the brightness/height information detection circuit 30 described above. Further, the selection circuits 28, 29 and 35, 38, .
This is provided for the purpose of saving 37, 38, 39 and reducing the load on the CPU 40 by adding preprocessing.

This brightness/height information detection circuit 30, 31, 32°33.
The output from 34 is sent to RAMs 35, 38, 37, 38, and 39 connected to the cptr4o bus. still,
The RAM 36 stores the data obtained by the unit inspection device 13 that irradiates the mounted printed circuit board with a beam spot almost perpendicularly. Similarly, the RAM 36 stores the data obtained by the unit inspection device 14, and the RAM 37 stores the data obtained by the unit inspection device 13. The data obtained by the inspection device 16 is stored in RAM3B, and the data obtained by the unit inspection device 16 is stored in RAM3B.
9 stores data obtained by the unit inspection device 17.

In the CPU4o, the RAM36.36.

37.38.39 Object 11 on the printed circuit board based on the height and brightness information obtained from multiple angles read out
7. Determine quality by reproducing an object more accurately and comparing it with pre-stored information.

Effects of the Invention As described above, the present invention irradiates a mounted printed circuit board to be inspected with a beam spot (Q) and moves the beam spot together with the photoelectric conversion elements arranged around it to irradiate each of the mounted printed circuit boards 1 and 1. Since the method measures changes in the height and brightness of a point, each point on the mounted printed circuit board is measured under the same conditions, and good inspection can be expected.

In addition, if the surface has a small inclination with respect to the perpendicular surface of the beam spot irradiation surface, the reflected light from the mounted printed circuit board is configured to be received by a plurality of photoelectric conversion elements arranged around the beam spot. Therefore, even if the reflected light from the mounted printed circuit board has various diffusion characteristics, it is possible to reduce the fluctuations in the inspection results caused by it.Furthermore, by changing the irradiation angle of the beam spot, it is possible to avoid extremely steep slopes relative to the mounted printed circuit board. However, the shape can be recognized extremely accurately.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a unit inspection device in which a beam spot projecting optical system and a light receiving optical system are integrated in one embodiment of the mounted printed circuit board inspection device of the present invention, and FIG. 2 is the same. FIG. 3 is a block diagram of an electric circuit of the inspection apparatus, and FIG. 4 is a perspective view of a conventional printed circuit board inspection apparatus. 1...Optical system for beam spot projection, 2,4°6.8...Photoelectric conversion element, 3,6,7.9...
... Lens%1o ... Printed circuit board, 11
...Beam spot, 12... Rotating disk, 13, 14, 16° 16.1 A... Unit inspection device, 24.25.26° 27... ... Height and brightness information detection circuit, 28 ... Height information selection circuit, 29 ... Brightness information selection circuit, 35.36,3
7, 38. 39...RAM, 40...C
PU0

Claims (1)

[Claims] A rotary body that is rotationally driven, a means for moving the printed circuit board to be inspected relative to the rotation thereof, and a means for moving the printed circuit board to be inspected relative to the rotation of the rotary body; a plurality of beam spot generating means disposed on the rotary body so as to irradiate the substrate with a beam spot and sequentially scan the printed circuit board with the rotation of the rotary body; A plurality of photoelectric conversion means are arranged radially around the beam spot and receive reflected light from the printed circuit board and output an output according to the light receiving position and an amount corresponding to the received light energy, An inspection device for a mounted printed circuit board, characterized in that information is obtained from multiple angles by changing the individual irradiation angles of the beam spot with respect to the printed circuit board.