JPH01454A - Object shape inspection device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] An object shape inspection device that inspects the shape of an object to be inspected by irradiating the object with a linear light beam and detecting the reflected light with a two-dimensional photodetector. In this method, the reflected light is divided horizontally by a mirror system, and each of them is vertically arranged and imaged on a two-dimensional photodetector, thereby using one two-dimensional photodetector. This allows a longer area to be detected at once.

[Industrial application field]

The present invention relates to an object shape inspection device that uses optical cutting to inspect, for example, the three-dimensional shape of a chip component mounted on a printed board.

[Conventional technology]

Conventionally, as a device for detecting the height of an object, the device shown in Fig. 6 (al.
A method using a photosection method as shown in FIG. 1 has been proposed. In the figure, for example, a linear light beam L is irradiated onto a printed board P on which a chip component Q is mounted using light l1liiIl and a cylindrical lens 2, and the reflected light is detected by a two-dimensional sensor 3 from diagonally above. It is supposed to be done. When there are irregularities on the printed board P, the two-dimensional sensor 3 obtains a light section image (FIG. 6(b)) having a shape corresponding to the irregularities. By determining the deviation h', the height h of the chip component Q can be determined, and by sequentially obtaining such images, the three-dimensional shape can be determined.

[Problem that the invention seeks to solve]

In the conventional device described above, the detected image obtained from the two-dimensional sensor 3 (see FIG. 6(b)) is, for example, 500 x 500
It has a substantially square shape about the size of a pixel. Therefore, for an object that is wide and short, such as a printed board P on which a chip component Q is mounted, the narrow part of the light beam irradiation area shown by the solid line in FIG. 6(a) is detected. Just by
There is a problem in that the portions on both sides indicated by dotted lines are not detected, and most of the vertical direction (vertical direction) of the detected image is wasted.

The present invention solves the above conventional problems and provides an object shape inspection device that makes effective use of detected images and can detect a longer area at once with one two-dimensional photodetector. With the goal.

[Means for solving problems]

The principle of the invention is shown in FIG. As shown in the figure,
By newly providing a mirror system T, the present invention can horizontally divide the reflected light obtained from the object N to be inspected by irradiation with the linear light beam L (not limited to two divisions), and can The reflected light beams are vertically aligned and imaged on a two-dimensional photodetector S.

[For production]

The above two-dimensional photodetector S can obtain a detection image with sufficient margin in the vertical direction (direction "a") as shown in Figure 6. Even if there is a long area on N (for example, the area including the dotted line in FIG. If the images are formed vertically side by side, they will be detected as one image without overlapping each other.In this way, each divided image will fit vertically into one approximately square detection image, so the detection will be easier. In addition to making effective use of images, it becomes possible to detect the long area mentioned above at once.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows the main parts of the detection optical system according to the first embodiment of the present invention.

In this embodiment, a mirror consisting of two pairs of mirrors (13, 14; 15, 16) is placed between the lens I2 for optical imaging on the two-dimensional CCD sensor 11 and the detection area R on the object to be inspected. This is a configuration in which the system is arranged. Here, the detection area R is defined as the center line of the two-dimensional CCD sensor 11 and the lens 12 (-dotted chain line).
Consider dividing it into two horizontally. mirrors 13 and 14
The reflected light (indicated by a solid line) from the detection region R5 is transmitted through the lens 12 to the lower region 11a of the two-dimensional CCD sensor 11.
The mirrors 15 and 16 are arranged to form an image of
It is arranged so that the reflected light (indicated by a broken line) from the other detection region R2 is focused on the lower region 11b of the two-dimensional CCD sensor 11 via the lens 12. In addition, in the figure, the path of light is shown with the light emitted from the center of each of the detection regions R1 and R2 as a representative.

The arrangement of the mirror system described above is shown in Figure 2 (bl and (
This will be explained in detail based on C). First, mirror 13.1
5 are symmetrical with respect to the optical axis in the same figure (bl), and are rotated by the same angle in opposite directions on the optical axis in the same figure (C1).
Contrary to the relationship in 3.15, in the figure (b), they rotate by the same angle in mutually opposite directions on the optical axis, and in the figure tel, they are symmetrical with respect to the optical axis. By changing the angles of the mirrors 14 and 16, the respective imaging positions on the two-dimensional CCD sensor 11 can be changed.

In one detection image obtained by the two-dimensional CCD sensor 11 as described above, as shown in FIG.
+ and M t are arranged in the vertical direction without overlapping each other. That is, one approximately square-shaped detected image includes the number of pixels (for example, about 1000 pixels) corresponding to twice the area of the conventional method. Therefore, 1. Not only can images be used effectively, but also an area twice as large as the above can be viewed at once.

The image detected in this way is sent to the height detection circuit 17 as in the conventional case, where the height of the component is determined based on the control of the controller 18.

At this time, since the height can be detected simultaneously for twice as many areas as in the conventional method, the overall inspection time is reduced to 1/2.

FIG. 4 is a perspective view showing essential parts of a detection optical system according to a second embodiment of the present invention.

In this embodiment, four pairs of mirrors (20, 21; 22, 23; 24° 25; 26, 2
7) is provided with a mirror system consisting of the following. The above four pairs of mirrors are divided into four detection areas RII+R11R.
13+ Each reflected light from R+a is transformed into two-dimensional C
A region J divided in the vertical direction of the CD sensor 11! till direct, 11j, 11-. 117, respectively. The relationship between mirror 20 and mirror 26 and the relationship between mirror 22 and mirror 24 are shown in FIG.
The relationship between the mirror 13 and the mirror 15 in FIG. 2 (bl, (C) is the same as that in FIG.
This is the same as the relationship between mirror 14 and mirror 16 in C1.

In this embodiment, one detection image obtained by the two-dimensional CCD sensor 11 includes four detection regions RI I +RI!
+ The respective light section images for R11 and R14 are arranged in the vertical direction. Therefore, it is possible to use a substantially square image even more effectively, and the area is four times larger than the conventional one (
For example, approximately 2000 pixels) can be viewed at - degrees. This reduces the inspection time to 174 times compared to the conventional method.

FIG. 5 is a plan view showing essential parts of a detection optical system according to a third embodiment of the present invention.

In this embodiment, six pairs of mirrors (30, 31i32, 33; 34°35; 36.3
7; 38.39; 40.41). Mirrors 30° 31 and mirrors 32, 33 are arranged so as to vertically combine the reflected light from two of the four divided detection areas R11+R12, and mirrors 34° 35 and mirrors 36, 37 It is arranged so that the reflected light from the two detection regions RI31 R+a may be combined in the vertical direction. The mirrors 38, 39 and 40, 41 further combine the two optical images obtained by combining in the above manner in the vertical direction and output the two-dimensional CCD sensor 1.
It is arranged so that an image is formed on 1.

In other words, the detection area R+++ R1t+R divided into four
By combining the reflected light from 11R+a in two stages, the two-dimensional CCD sensor 1
The images are formed vertically on the top of the screen.

The arrangement of mirrors 30 to 33, mirrors 34 to 37, and mirrors 38 to 41 is substantially the same as the arrangement of mirrors 13 to 16 in FIG.

In this embodiment, as in the second embodiment, an area four times as large as the conventional one can be viewed at once, so the inspection time is reduced to 1/4.
can be shortened to Furthermore, all mirror angles are 4.
5 degrees, and multiple identical units can be used (e.g. mirrors 31, 33, mirrors 35, 37 and mirror 39).
．． Since the same unit can be used for all the mirrors 41 and mirrors with approximately the same angle can be used for all the remaining mirrors, there is also the advantage that the manufacture and adjustment of the mirror system becomes very easy.

Note that the mirror system may be configured to divide the divided images into more parts as long as the divided images do not overlap with each other.Furthermore,
The configuration of the mirror system is not limited to the configuration described above, and the reflected light from the detection area is horizontally divided into 7
Any configuration may be used as long as they can be arranged vertically on the two-dimensional sensor.

Furthermore, various types of two-dimensional sensors can be used in addition to the two-dimensional CCD sensor.

Furthermore, the inspection target can be applied to various objects other than printed boards with components mounted thereon, as long as they include objects that are not very tall.

〔Effect of the invention〕

As explained above, according to the present invention, even if there is a long area on the object to be inspected that could not be detected conventionally, the reflected light from the area is divided and arranged vertically on a two-dimensional photodetector. Since each divided image can be imaged into one detected image, it is possible to use the image effectively, and the long area mentioned above can be detected at once, which also makes it possible to shorten inspection time. .

[Brief explanation of drawings]

Fig. 1 is a diagram of the principle of the present invention, and Fig. 2 (al, (bl, TC)) is a diagram of the principle of the present invention.
FIG. 3 is a perspective view, plan view, and side view showing essential parts of a detection optical system according to an embodiment of the present invention; FIG. 3 is a diagram showing an example of a detected image of the two-dimensional CCD sensor 11 and an image processing system; FIG. 5 is a perspective view showing the main parts of the detection optical system according to the second embodiment of the present invention, FIG. 5 is a plan view showing the main parts of the detection optical system according to the third embodiment of the present invention, and FIG. 2) are a perspective view showing an optical system of a conventional device and a diagram showing an example of a detected image of a two-dimensional sensor, respectively. 11... Two-dimensional CCD sensor, 13.14.15.16... Mirror, 20.21.2
2,23°24.25.26.27...Mirror, 30.31,
32.33, 34, 35, 36° 37.38, 39, 4
0.41... Mirror, L... Linear light beam, N... Target to be inspected, T... Mirror system, S... Two-dimensional photodetector.

Claims (1)

[Claims] 1) A linear light beam (L) is irradiated onto the object to be inspected (N), and the reflected light is detected by a two-dimensional photodetector (S) to obtain a light section image; The object to be inspected (N
) in an object shape inspection device for inspecting the shape of a mirror system ( An object shape inspection device comprising: T). 2) The mirror system includes two pairs of mirrors (13, 14; 15,
16), which divides the irradiation area of the light beam on the object to be inspected into two in the horizontal direction and directs the reflected light from each area through each mirror pair of the mirror group. 2. The object shape inspection apparatus according to claim 1, wherein images are vertically aligned and formed on the two-dimensional photodetector. 3) The mirror system includes four pairs of mirrors (20, 21; 22,
23; 24, 25; 26, 27), and the reflected light from each area obtained by dividing the irradiation area of the light beam on the object to be inspected into four in the horizontal direction is reflected by the mirror group. 2. The object shape inspection apparatus according to claim 1, wherein images are vertically aligned and formed on the two-dimensional photodetector via each pair of mirrors. 4) The mirror system includes six pairs of mirrors from the first to the sixth (
30, 31; 32, 33; 34, 35; 36, 37; 3
8, 39; 40, 41), of the first to fourth areas obtained by horizontally dividing the irradiation area of the light beam on the object to be inspected into four. The reflected lights from the first and second regions are combined in the vertical direction via the first and second mirror pairs, respectively, and the reflected lights from the third and fourth regions are combined into the third and fourth regions, respectively. 4 mirror pairs in the vertical direction, and the two light images obtained by the combination are arranged vertically on the two-dimensional photodetector via the fifth and sixth mirror pairs, respectively. The object shape inspection device according to claim 1, characterized in that the object shape inspection device forms an image. 5) The two-dimensional photodetector is a two-dimensional CCD sensor (11)
Claims 1 to 4 are characterized in that:
The object shape inspection device according to any one of the items. 6) The object shape according to any one of claims 1 to 5, wherein the object to be inspected is a printed board (P) on which a chip component (Q) is mounted. Inspection equipment.