JPH02187605A - Parts position and attitude checking device - Google Patents

Abstract

PURPOSE:To offer a parts position and attitude checking device capable of short-time processing for parts to which many kinds of attitude angle are commanded by operating a light shielding mechanism in accordance with the attitude command angle of parts to select a first or second optical path system and picking up the image with a camera. CONSTITUTION:The local image of SOP electronic parts 2 attracted to an atraction head 1 is branched to a transmission optical path P and a reflection optical path R in two directions by a beam splitter 7, and branched images are synthesized on the image pickup element of a camera 15 through optical path converters 8' and 9'. Each of optical path converter 8' and 9' consists of four rectangular prisms, and they are provided in attitudes turned at 90 deg. around optical axes of the transmission optical path P and the reflection optical path R respectively. A shutter 13 is switched to the optical path P or R in accordance with the command value of the attitude angle of SOP electronic parts 2, and the silhouette image processed by the optical path converter 8' or 9' is taken in from the camera 15 to calculate the displacement and the angular displacement of a lead of electronic parts 2, and it is discriminated whether they are abnormal or not.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus suitable for inspecting electronic components sucked by a suction head of an electronic component mounting machine, for example.

"Prior Art" An electronic component mounting machine uses a suction spatula 1- to adsorb electronic components supplied from a supply device and mounts them onto a printed circuit board. In order to mount an electronic component on a printed circuit board at the correct position and angle, it is necessary to inspect whether the position and orientation of the electronic component sucked by the suction head is correct.

Several methods have been devised in the past for inspecting the position and orientation of lead-attached electronic components picked up by the suction head of an electronic component mounting machine using images taken with a camera. As described above, inspection is performed using only local images of specific parts of electronic components. When attaching electronic components with leads to printed circuit boards, it is important to place the leads in the correct position and orientation on the metal parts called lands on the board.
When inspecting the position and orientation of an electronic component with a lead attached to a suction head before attachment, the position of the lead is often detected.

Generally, there are the following methods for obtaining a plurality of local images of a glued electronic component. The first is a method of providing a rough 1-ware window on an image obtained through a single optical path system, and the second is a method of forming locally enlarged images from multiple optical path systems on image pickup devices of separate cameras. Third.
This is a method of combining multiple locally enlarged images onto a single camera imaging device using optical means such as prisms and mirrors.

Among these methods, the third method can combine multiple local images dispersed over a wide area into one image with high image resolution in the field of view of one camera, so it can shorten the time required for imaging and It has the advantage of making it possible to downsize.

[Problems to be Solved by the Invention] Among the above-mentioned conventional techniques, the first method has the advantage of being able to extract a local image of any part on the screen by programming, but cannot obtain sufficient image resolution. There may be no. In such cases, the second method or the third method
．． However, in all of these methods, the position of the locally enlarged image or the direction of movement during synthesis is fixed.

Therefore, when inspecting a 5OI (small 1-line package) electronic component with many leads lined up in parallel at both ends of the package, it is recommended to magnify the lead portions on both sides. When the above second or third method is applied, as shown in Fig. 7, it works only when the attitude angle of the component with respect to the screen is opposite to each other, as shown in Fig. 7 (a) and (b). The problem is that it doesn't.

Practically speaking, the minimum attitude angle for mounting SOP electronic components on a board is horizontal (0°C, 180°C) and vertical direction (90°C).
℃, -90℃), so if you try to inspect the position and orientation of the SOP electronic component given the attitude angle, the second method above requires 4
In addition, the third method described above can only support attitude angles in either the horizontal direction or the vertical direction, and both methods are difficult to apply to SOP electronic components.

As a solution to this problem, if the optical path system and camera are made movable, the detection accuracy will decrease due to mechanical errors, and the position and
Those that are not suitable for the purpose of posture testing are a winner.

An object of the present invention is to provide a component position/orientation inspection device that can perform processing in a short time while maintaining a wide field of view and high resolution for components for which a wide variety of orientation angles are commanded, and an optical path changing device suitable for use therein. Our goal is to provide the following.

[Means for Solving the Problems] The component position/orientation inspection device of the present invention has a first optical path including a first optical path conversion device that combines local images of two parts of one component on an image sensor of a camera. system, and local images of two other parts of the part that are different from the two parts synthesized by the first optical path system including the first optical path conversion device are synthesized on the image pickup device of the second camera. It is characterized by comprising a second optical path system including a second optical path conversion device, and a light shielding mechanism for selecting either one of these two optical path systems.

In addition, the optical path conversion device suitable for use in this inspection device is
It is equipped with four right angle prisms in the form of right isosceles triangular prisms, and among these right angle prisms, the first and second right angle prisms 11
, the slopes of each right-angled isosceles triangular prism are brought into close contact with each other,
Alternatively, the slopes are parallel to each other at a certain interval and are installed in a direction perpendicular to the optical axis of the optical path, and the third and fourth right-angle prisms 11 are the first and second right-angle prisms described in -. The third and fourth rectangular prisms are placed on both sides of the optical axis with their slopes facing inward, with the ridgelines of the four rectangular prisms being parallel to each other. is displaced by a predetermined distance ld along the optical axis, that is, toward the output side, with respect to the first and second rectangular prisms.

[Operation] By setting the light shielding mechanism in accordance with the attitude command angle of the component and selecting either the first or second optical path system and capturing the image with the camera, the part that is well adapted to the attitude command angle is Position/posture inspection can be performed.

[Embodiment] FIG. 3 shows the simplest example of an optical path changing device for image synthesis used in the present invention. It is assumed that the SOP-electronic component 2 to be inspected, which is suctioned by the suction hem 1, is imaged from the side that is not suctioned.

The lines with arrows in the figure indicate the light rays coming from the electronic component 2. FIG. 3(a) shows an optical path changing device consisting of four plane mirrors 3, FIG. 3(b) shows an optical path changing device consisting of three right angle prisms 4, FIG. 3(c) and (d) is an optical path changing device each composed of two plane mirrors 5 and two right angle prisms 6. All of these optical path conversion devices are SOP type electronic components 2 shown in the figure.
It has the function of composing the images of the reeds 2□, 2□ on both sides of the package part 2□ which are separated from each other so that they are adjacent to each other as images. Figure 4 (,) shows the image before compositing, and Figure 4 (b)
The images after synthesis are shown in schematic diagrams.

FIG. 5 schematically shows an embodiment of an electronic component position/orientation inspection device according to the present invention using, for example, the 16-way conversion device shown in FIG. 3(b). As shown in the figure, the optical path from the SOP electronic component 2 is split into two by a beam splitter, and the optical path converter 8 (shown in FIG. 3(b)) is installed on one side, and the optical path converter 8 (shown in FIG. 3(b)) is installed on the other side. Around 1・111 ≦〕0°
A similar rotated optical path conversion device 1] is installed. , these optical path converters 8, 9], respectively.
．． The beams are bent at right angles by the beam splitter 11, merge again by the beam splitter 12, and are input to the camera. A shutter 1:3 is provided in the middle of the optical path from the optical path converters 8 and 9 to the beam splitter 12.
It is operated by a signal issued by the control device in accordance with the command value of the attitude angle of the component 2, and one of the optical paths is blocked to obtain a composite image that matches the inspection target in the camera.

The SOP electronic component 2 is suctioned at the attitude angle shown in Figure 0! ~
1, the output image of the optical path changing device 8 is effective for inspecting its position and orientation, so the shutter 13 should pass through the output of the optical path changing device 8 as shown. , is operated to cut off the output of the optical path changing device 9. On the other hand, if the attitude angle of the SOP completed part 2 that is attracted to the suction hem 1~1 is 90 degrees around the axis of the suction hem 1~1 than the attitude angle shown in FIG.
Since the output image of the optical path changing device 9 is effective for inspecting its position and orientation, the shutter 13
It is operated to pass the output of the optical path changing device 8 and cut off the output of the optical path changing device 8.

In this way, the above embodiment is particularly suitable for SOP electronic components for which four attitude angles of 0°, 90°, 180°, and -90' are commanded in 90° increments. In order to make the posture inspection RQ-enabled, as shown in Fig. 6, the optical paths are symmetrical around the optical axis, A, B, C, and D.
A first optical path system that obtains local images of two parts and synthesizes the local images of parts A and C, and a second optical path system that synthesizes local images of parts B and D are provided. The shutter is switched at an appropriate timing based on a signal issued by a control device according to the attitude angle, and an optical path system is selected to input an image.

Next, a preferred embodiment of the electronic component position/attitude inspection apparatus according to the present invention will be described with reference to FIGS. 1 and 2. The principle of this embodiment is similar to that of the previous embodiment.

As shown in FIG. 1, the electronic component position/attitude inspection apparatus according to the present embodiment includes an illumination means 14, an optical system, a shutter 13,
It is composed of a camera 15, an image processing device 16, and an electronic component mounting machine control device 17. It is assumed that the SOP electronic component 2 is sucked into the suction port 1<1 of the electronic component mounting machine.

An illumination means 14 is provided near the SOP electronic component 2, and a light shielding wall 18 is placed between the two, so that the light from the illumination means 14 is provided near the SOP electronic component 2.
The electronic component 2 is irradiated with the irradiation, but the background portion 19 is irradiated with the irradiation.

Suppose that the electronic component 2 is photographed from the side that is not sucked, that is, from the bottom in FIG. 1, and a silhouette image of the SOP electronic component 2 is obtained in the background area 19. The optical path from the electronic component 2 is bent by 90 degrees by the front mirror 2o, and then branched into two directions, a transmission side optical path P and a reflection side optical path R, by a first beam splitter.

An optical path changing device 8' consisting of four right angle prisms is provided on the transmission side optical path (2).

This optical path changing device will be explained with reference to FIG. The first right-angle prism 2'' and the second right-angle prism 22 are aligned so that the slopes of their respective right-angled isosceles triangular prisms are aligned with each other, their centers are aligned with the optical axis, and they are oriented in a direction perpendicular to the optical axis. A third right-angle prism 23 and a fourth right-angle prism 24 are placed on both sides of the prism 23 and 24 with their slopes facing inward, with the same distance a spaced between them. However, these prisms are 23°2
4 is shifted by a distance d toward the rear (output side) along the optical axis from the slope position of the inner prisms 1121 and 22. Required portions of the surfaces of the first and second prisms 21.22 are treated to increase reflectance, such as by vapor deposition of aluminum, and antireflection coating is applied to the slopes of the third and fourth prisms 23.24.

Parallel light bt+bz+b3+b is applied to this optical path changing device 8'.
4 is incident in the optical axis direction, the ray b2.4 is separated by a distance of 4d. b3 is emitted at the same position as ray b' 2 l b' 3. Since the SOP electronic component 2 is placed far enough away compared to the size of the optical path converter 8', the SOP electronic component 2
The light from the OP electronic component 2 is the above-mentioned light ray b□.

b2. b3. It can be approximated by b4. Therefore, the optical path changing device 8' outputs an image in which the central part of the image of the SoP electronic component 2 is omitted over a width 4d.

Furthermore, a similar optical path changing device 9' is installed in the reflective side optical path R reflected by the first beam splitter in a position rotated by 90 degrees around the optical axis compared to the optical path changing device 8'. The transmission side optical path P and the reflection side optical path R pass through optical path converters 8' and 9', respectively, are bent by 90 degrees by front mirrors 10 and 11, enter a second beam splitter 12, merge, and pass through the front mirror. 2] and enters the camera 15.

A shutter 13 is provided so as to selectively allow only one of the transmission side optical path P and the reflection side optical path R to pass through by sliding operation. The electronic component mounting machine control device 17 turns on the illumination means 14 so as to obtain optimal imaging conditions according to the type of the SOP electronic component 2 to be inspected next, and also outputs a command value for the attitude angle of the SOP electronic component 2. ′, a switching command for the shutter 13 is issued to a shutter drive device such as a solenoid or a pneumatic cylinder, and the image processing device 1
6, the type of electronic components and the command value of the attitude angle are transmitted. In response to this, the image processing device 16 captures from the camera 15 the images processed as described above by the optical path conversion device 8' or 9', and calculates the displacement and angular displacement of the leads of the SOI' electronic component 2. is calculated, the presence or absence of an abnormality is determined, and the result is returned to the electronic component mounting machine control device 17.

When the attitude angle shown in FIG. 1 is given to the SOP electronic component 2, the shutter 13 is located at the position shown in the diagram so that the light path on the transmission side is in direct contact with the other parts, the SOP electronic If the attitude angle of the component is 90 degrees, use shutter 1.
3 is operated so that the reflection side optical path R becomes effective.

In this embodiment, the shutter J3 is of the slide+< type, but a plate that rotates about an axis may also be used. Alternatively, a lens diaphragm may be used. Furthermore, the optical path may be opened and closed by stacking two polarizing plates and rotating at least one of them.

As an illumination method for generating an image on the silica 1 of the SOP electronic component 2, instead of the illumination means 14, the background portion 19 may be illuminated at one point using optical fiber illumination. Furthermore, instead of an image on the Silera 1, it is also possible to use a bright image obtained by directly illuminating the SOP lighting component 2. In this embodiment, the beam 1, the splitter 7.
, 11 to form a rectangular optical path,
This may be for the purpose of making both optical path lengths curved. According to this embodiment, since the optical path lengths of the two screen parts to be synthesized, that is, the double-edged portions of light beams b2 and l)4 shown in FIG. 2, are the same, the synthesis is 10! It has the characteristic that the focus of the cow is perfectly aligned and a clear image is printed. According to the signs.

The problem that the optical path lengths of the two screens are different, which occurs in FIG. 3(b) or (d), can be solved.

Furthermore, according to this embodiment, the value of the distance d shown in FIG. 2 can be freely set within a certain range from 0 to
) or (b), in which the field of view becomes narrower if the width of the omitted central portion is narrowed, does not occur in this embodiment.

Note that the value of the distance d in Figure 2 is set so that the distance 4d is slightly smaller than the width of the package for the type of SOI) electronic component 2 to be inspected that has the smallest width of the pancage part. It is convenient to set this.

Furthermore, the first and second prisms 2L 22 are
and the fourth prism 23, 24, and is provided with a prism drive device for such movement, to determine the optimum distance d value according to the type of SOI electronic component to be inspected. If d is determined in advance and a position command corresponding to the value of d is given to the prism drive device during inspection, the present device can be applied to more types of electronic components.

In addition, by using the apparatus of this embodiment and imaging twice using the two optical paths i1°R in sequence, it is also possible to inspect the position and orientation of electronic components such as QFP electronic components that have leads in four directions. It is possible.

In the embodiment of the electronic component position/attitude inspection device described above, the respective optical path changing devices in the two optical paths are arranged at angles rotated by 90 degrees with respect to the optical axis, thereby making it possible to This is adapted to the normal attitude command angle in 90° increments, but if the mutual rotation arrangement angle of both optical path conversion devices is set to an arbitrary angle other than 90°, the attitude command angle can be given in arbitrary angle increments. It is also possible to inspect the position and orientation of electronic components for four of these orientation command angles. Furthermore, if a large number of optical path changing devices are provided and one optical path changing device can be selected, it is of course possible to inspect the position and orientation of the electric Y component even for attitude command angles in arbitrary angle increments.

[Effects of the Invention] According to the present invention, J of two parts at different angles of the part
Since I' three-position image synthesis can be selectively used,
Even for different orientation command angles, the position and orientation of a part can be accurately inspected using a composite image of two appropriate parts of the part1.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the overall configuration of an embodiment of the present invention, FIG. 2 is an explanatory diagram of the optical path conversion device in FIG. 1, and FIG.
a) to (d) are diagrams showing other different examples of the optical path changing device used in the present invention, and FIG. 4(a). (b) is a diagram showing the images before and after composition, respectively.
The figures show another embodiment of the present invention, FIG. 6 is a layout diagram of the local screen around the optical axis in the embodiment, and FIG. 7(a)
, (b) are diagrams showing electronic component postures that can be detected by a conventional device. 1. Suction head 2. S OP electronic components 7.. 1st
beam splitter 8.9... optical path changing device 8', 9'... optical path changing device 10.11... surface mirror 12, second beam splitter ]3, shutter 14,
Illumination means 15...Camera 16...Image processing device 17...Electronic component mounting machine control device 20.21/Surface mirror

Claims (1)

[Scope of Claims] 1. A first optical path system including a first optical path changing device that combines local images of two parts of one part on an image sensor of a camera; and a first optical path system including the first optical path changing device. A second system that combines local images of two other parts of the component, which are different from the two parts that are combined by the first optical path system, on the image sensor of the camera.
A component position/orientation inspection device comprising: a second optical path system including an optical path changing device; and a light shielding mechanism for selecting one of these two optical path systems. 2. The first optical path system and the second optical path system are branched from a single optical path system by a first beam splitter, and after passing through the first optical path conversion device and the second optical path conversion device, respectively, The first optical path changing device and the second optical path changing device are configured to merge together again and reach the camera by a second beam splitter, and the first optical path changing device and the second optical path changing device respectively move the two beams in different directions on the image sensor screen of the camera. 2. The component position/orientation inspection device according to claim 1, wherein the component position/orientation inspection device is arranged to move and synthesize local images of a part. 3. The first optical path system including the first optical path changing device forms local images of two parts of one component on the left half and right half of the image sensor screen of the camera, and the first optical path system includes the first optical path changing device. 3. The second optical path system including the optical path changing device forms local images of two other parts of the component on the upper and lower halves of the image sensor screen of the camera. Part position/attitude inspection device. 4 Equipped with four right-angled isosceles triangular prisms,
Among these right-angle prisms, the first and second right-angle prisms are arranged so that the slopes of the respective right-angled isosceles triangular prisms are in close contact with each other, or the slopes are parallel to each other with a certain distance between them, and are perpendicular to the optical axis of the optical path. The third and fourth rectangular prisms are placed on both sides of the optical axis with the first and second rectangular prisms in between, with their slopes facing inward. The ridgelines of the triangular prisms of the right-angle prisms are parallel to each other, and the third and fourth right-angle prisms are moved a predetermined distance d backward, that is, on the output side, from the first and second right-angle prisms along the optical axis. An optical path changing device characterized by being displaced. 5. The set of the first and second right angle prisms is relatively movable in the front and back direction along the optical axis with respect to the third and fourth right angle prisms, so that the value of the distance d can be adjusted. The optical path changing device according to claim 4. 6. The component position/attitude inspection device according to claim 1, 2 or 3, wherein the optical path changing device according to claim 4 or 5 is used as the first optical path changing device and the second optical path changing device.