JPH03203251A - Detector to detect bent lead of electronical components - Google Patents

Abstract

PURPOSE:To eliminate the need for bringing leads into close contact with semi- transparent sheets or the like one by one during bending detection by irradiating light to the leads, photographing an image formed by the light which has penetrated between the leads, and detecting their bends based on the image. CONSTITUTION:Both a horizontal bend and a vertical bend of a lead 82 are detected from an image 100. More specifically, a bend of each lead 82 can be detected by placing an image under a state which excludes holding position errors x, y, theta of an image actually obtained by a camera device, upon a normal state of image (the image of an electronic component 78 where each lead is free from a horizontal bend and a vertical bend.), and examine whether or not the actual image is deviated from the normal image. This construction makes it possible to eliminate the need for bringing each lead into close contact with semi-transparent sheets or the like one by one.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for detecting bending of lead wires of an electronic component having a large number of lead wires protruding from a main body. The present invention relates to the detection of bending of a lead wire in a direction perpendicular to a plane to be detected.

BACKGROUND OF THE INVENTION Some prior art electronic components have multiple lead wires attached to their bodies. Electronic components called flat package type electronic components, plastic lead chip carriers, etc. are one type of electronic component, and these types of electronic components are soldered to the printed wiring of the target object such as a printed circuit board at the tip of the lead wire. .

For this reason, the tips of the many lead wires are originally located on a flat plane, so that all the lead wires are soldered to the printed wiring without fail. In this case, the tip of the lead wire is usually bent almost parallel to the main body, and the soldering area is large enough to ensure continuity, and when installed, the electronic component is held by the holding means. The tip of the lead wire is fixed in a state in which it is in direct contact with the printed wiring on the object to be mounted, or in a state in which it is in indirect contact through solder or the like.

When such an electronic component is mounted on an object, if the lead wire is bent, it will not be properly soldered to the printed wiring, resulting in a defective product. Therefore, JP-A-62-76529
In the electronic component mounting apparatus described in the publication, it is detected whether or not the tip of the lead wire is bent in a direction perpendicular to a plane on which the lead wire should originally be located. Detection of this bend (this bend is referred to as a perpendicular bend to distinguish it from a parallel bend, i.e., a bend in a direction parallel to the plane) is a method for detecting the tip of the lead wire. Information obtained by irradiating light from the electronic component side toward the translucent plate while in close contact with the translucent plate, and imaging the shadow of the lead wire on the translucent plate from the back side of the translucent plate. This is done by comparing with reference information corresponding to a normal electronic component with no bends in the Riet wire. If the tip of the lead wire is in close contact with the semi-transparent plate, a clear shadow will appear on the semi-transparent plate, but if it is not in close contact, the shadow will be unclear or small, making it difficult to match the standard information. There is a discrepancy between the two, and bends in the right angle direction can be detected.

If the bend in the lead wire in the right angle direction is detected in this way,
By stopping the installation of defective electronic components or correcting the lead wires before use based on the detection results, soldering can reduce the occurrence of defective electronic circuits due to defects.

Problems to be Solved by the Invention However, when detecting a bend in the right angle direction of a lead wire in this way, it is necessary to bring the lead wire of the electronic component into close contact with the semi-transparent plate and separate it from the translucent plate, which makes detection difficult. It is unavoidable that it takes a long time, but if the detection is performed when the electronic component is mounted, a problem arises in that the mounting time becomes long. Additionally, there is a limit to increasing the accuracy of detecting bends.

The first invention is to take an image of the bending of the lead wire in the right angle direction for each tip of the lead wire on one of the four sides or two sides parallel to each other, and to bend the lead wire in the right angle direction without touching the lead wire. The object of this invention is to provide a lead wire gap detection device that can detect bends.

A second aspect of the present invention is to provide a lead wire gap detection device capable of capturing images of the lead wires on four sides in one imaging operation and detecting bends in the right angle direction without contacting the lead wires. This was done with this in mind.

Means for Solving the Problems In order to solve the above-mentioned problems, the lead wire gap detection device of the first invention has the following features: (a) A large number of lead wires whose tips should be located on one plane are separated from the main body. (b) A light source that irradiates light onto a protruding lead wire of an electronic component, and (b) a light source that is provided on the opposite side of the lead wire from the light source and that forms the tip of the lead wire that is formed by the light transmitted between the lead wires. An imaging device that photographs an image and whose imaging direction is tilted with respect to the direction in which the lead wires are lined up; The invention is characterized in that it includes a bending detection means for detecting a bending.

The lead wire gap detection device of the second invention is characterized in that: (a) a lead wire of an electronic component is formed by a large number of lead wires, each of which has a leading end located on one plane, protruding from each of the four sides of a rectangular main body; (b) An image of the entire electronic component formed by the light emitted by the light source is captured in one imaging operation, and the imaging direction is set for all four sides of the main body of the electronic component. and an imaging device tilted at (
C) A bending detection means for detecting bending of the lead wire based on images of the tips of the lead wires taken by the imaging device.

Note that one imaging operation means that no operation other than the imaging operation is performed while images of the tips of all lead wires are taken, and images of the tips of all lead wires are taken at the same time. This includes not only cases where images are taken sequentially with a time lag, but also cases where images are taken sequentially with a time lag.

Further, in the second invention, the image of the tip of the lead wire may be formed by providing the light source and the imaging device on opposite sides of the lead wire, and using light transmitted between the lead wires. Alternatively, the light source and the imaging device may be provided on the same side with respect to the lead wire, and the light may be formed by reflected light.

Operation In the bending detection device of the first invention, the image of the tip of the lead wire is taken on one of the four sides or every two sides that are parallel to each other, and the lead wire is attached to all four sides. In some cases, the imaging operation is repeated until images of all the lead wires are obtained, and between the imaging operations, for example, the electronic components are rotated or moved to the front side of the imaging device. Operations other than the imaging operation, such as a return operation, are performed, and the next imaging is performed. In this detection device, since the imaging direction of the imaging device is inclined with respect to the direction in which the lead wires are lined up, when the lead wire is bent in the right angle direction, the position is different from that when there is no bend. An image is formed on the lead wire, and based on the position data of the tip of the lead wire obtained from the image, it can be determined whether or not a bend in the right angle direction has occurred.

In the bending detection device of the second invention, since the imaging direction of the imaging device is inclined with respect to all four sides of the main body of the electronic component, all the parts protruding from each of the four sides by one imaging operation are If the lead wire has a bend in the right angle direction, the image will be formed at a different position than if the lead wire had no bend.

Effects of the Invention As in the first invention, if the lead wires are irradiated with light, an image formed by the light transmitted between the lead wires is photographed, and a bend is detected based on the image, bending can be detected in the right angle direction. It is possible to detect bends in a non-contact manner, and there is no need to bring the lead wire into close contact with a translucent plate or the like each time a bend is detected, and the detection time and electronic component mounting time can be shortened. In particular, when detecting bends by moving electronic components and imaging devices relative to each other, it is possible to use a dedicated There is no need to provide a moving device, and detection can be performed at low cost and efficiently. Further, it is easier to improve the detection accuracy compared to the case where bending in the right angle direction is detected by closely contacting the translucent plate.

Further, in the second invention as well, bending is detected by irradiating the lead wire with light and photographing an image formed by the light transmitted between the lead wires or the light reflected from the tip of the lead wire. Therefore, it is possible to detect without contact, and all position data of the tips of the lead wires on four sides can be obtained in one imaging operation, and no other operations are performed during the imaging operation. Detection time can be significantly reduced.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram showing an electronic component holding device that holds electronic components for mounting them on a printed circuit board.

In the figure, reference numeral 8 denotes a frame, and an x-y table 1o is attached to the frame 8, which can be moved in the X direction and the X direction, which are perpendicular to each other in a horizontal plane. This table 10 is driven by a surfboard motor or the like, and is positioned with high precision at any position within a horizontal plane. The table 10 also includes a linear slide 12 that is moved vertically by a drive device (not shown).
is provided, and the holder 1 is mounted on this linear slide 12.
4 is fixed. The holder 14 has an arm portion 16 extending horizontally from its lower end, and a cylindrical member 18 is rotatably supported by the arm portion 16 via a sleeve 020 around a vertical axis.

The cylindrical member 18 has a stepped shape, and is fitted into the sleeve 20 at its small diameter portion 26 so as to be movable in the axial direction.
At the engagement hole 30 provided in the large diameter portion 28, the sleeve 2
0, and is prevented from rotating relative to the sleeve 20. Further, an air passage 34 is formed in the cylindrical member 18 by passing through its center in the axial direction, and a nut 3 is provided at the upper end.
6 is fixed. A connecting fitting 40 of a rubber vacuum hose 38 is screwed into the nut 36, thereby connecting the cylindrical member 18 to a vacuum source (not shown). A compression coil spring 46 is disposed between the sleeve 20 and the protruding end of the cylindrical member 18 from the sleeve 20, so that the large diameter portion 28 of the cylindrical member 18 comes into contact with the upper surface of the sleeve 20. I'm forced to.

Further, a large-diameter gear 50 is integrally provided at the upper portion of the sleeve 20 projecting from the arm portion 16, and is meshed with a small-diameter gear 52 rotatably supported by the arm portion 16. This small diameter gear 52 has a medium diameter gear 54.
is fixed, and the medium diameter gear 54 is meshed with the drive gear 58. The drive gear 58 is rotated by a servo motor 60 attached to the linear slide 12 by a bracket 59. As a result, the medium diameter gear 5
4. The large diameter gear 50 is rotated via the small diameter gear 52, and the cylindrical member 18 is rotated together with the sleeve 20.

Furthermore, an outward flange portion 64 is provided at the lower end of the cylindrical portion 18 protruding from the sleeve 20, and the light emitting plate 6
6 is fixed by screws 68. The light emitting plate 66 is
A main body 70 having a plate shape and fixed to the flange portion 64;
The lower surface of the main body 70 is provided with a light-emitting layer 72 coated with fluorescent paint. An air passage 74 is formed in the light emitting plate 66, passing through it in the thickness direction and coaxial with the air passage 34 formed in the cylindrical member 18. One end of the air passage 74 opens at the center of the surface of the light emitting layer 72, and the other end is connected to a vacuum source via the air passage 34. A suction tube 76 made of metal with excellent wear resistance is press-fitted into the side of the air passage 74 that opens to the surface of the light emitting layer 72 . The suction tube 76 is thinner than the electronic component 78, and its surface, together with the lower surface of the main body 70, is coated with fluorescent paint to form a light emitting layer 80. The suction pipe 76 suctions and releases the electronic component 78 in response to switching of an electromagnetic directional valve provided in the vacuum source.

As shown in FIGS. 2 and 3, the electronic component 78 includes a rectangular main body 81 and a plurality of lead wires 8 attached at equal intervals to each of the four sides (side surfaces) of the main body 81.
From 2 onwards. The lead cotton 82 is extended parallel to the plate surface of the main body 81, then bent at right angles to the plate surface, and further bent away from the main body 81 to have a tip 83 parallel to the main body 81. ing. Each tip 83 is positioned in one plane, and is soldered to a printed circuit on a printed circuit board at this tip 83. In this embodiment, the main body 81 of the electronic component 78 is held horizontally by a suction tool 76 and is mounted on a horizontally supported printed circuit board, and the tip portions 83 of a large number of lead wires 82 are placed on one plane. is a horizontal plane, and the direction perpendicular to this plane is the vertical direction.

Furthermore, an imaging device 84 is attached to the frame 8 . This imaging device 84 is equipped with a lens 86 and a camera 88, and the camera 88 has a curved imaging direction and is positioned at the detection position of the main body 81 of the electronic component 78.
The bend detection position is the intersection of the plane in which the lead wire tips are lined up and the center line of the suction tube 76, so that the center line of the suction tube 76 This is the position located on the axis. In this embodiment, the imaging device 84 is tilted by 15.5 degrees with respect to two sets of mutually parallel sides of the main body 81. The lens of the imaging device 84 A ring lamp 90 is provided around the light emitting plate 86 and is attached to the frame 8 via a bracket (not shown). is provided with an annular first filter 92 that allows only ultraviolet light to pass through, and is supported by the bracket.Therefore, the light emitting plate 66 is irradiated with only ultraviolet light, and the light emitting layer formed by applying fluorescent paint 72
．． 80 absorbs the ultraviolet light and emits visible light. The wavelength of the light emitted to the light emitting plate 66 and the wavelength of the light emitted by the light emitting plate 66 are different from each other, and the light emitting plate 66 constitutes a light source. Furthermore, the imaging device 84 has a lens 86 in close proximity to the lens 86;
A second filter 94 is provided at a position facing the electronic component 78 and supported by a bracket that supports the first filter 92. This second filter 94 absorbs ultraviolet rays while allowing visible light to pass through, and is used for the imaging device 8.
Only the visible light emitted by the light emitting layers 72 and 80 enters the electronic component 4, and an image formed by the light transmitted between the lead wires 82 of the electronic component 78 is photographed.

The electronic component holding device configured as described above receives the electronic components 78 from the component supply device and mounts them on a printed circuit board. The bend detection position is set between the component receiving position and the mounting position, and the electronic component 7 is placed at this position.
8, the holding position error of the main body 81 and the bending of the lead wire 82 are detected, and after the holding position error is corrected, the electronic component 78 is mounted on the printed circuit board, and the bending of the lead wire 82 is not suitable for mounting. The electronic components 78 that are too large are discarded. Note that the holding position errors include positional errors ΔX and Δy in the X-axis and y-axis directions set in the electronic component holding device between the center line of the main body 81 and the center line of the suction tube 76, and the main body 8
An angular error Δθ around the center of 1 is detected.

When receiving the electronic component 78, the linear slide 12 is lowered with the suction tube 76 positioned above the electronic component 78 to be picked up in the component supply device, and the suction tube 76 comes into contact with the top surface of the electronic component 78. I am made to do so. Even after contact, the suction tube 76 is moved down slightly by compressing the compression coil spring 46 and moving relative to the sleeve 20. 5 6 damage to the adsorption tube 76 is avoided. In this state, the suction tube 76 is communicated with a vacuum source to suction the electronic component 78.

Thereafter, the linear slide 12 is raised, the x-y table 10 is moved, and the suction tube 76 is positioned at the bend detection position. Of the light emitted from the ring lamp 90, only the ultraviolet rays pass through the first filter 92 and are emitted toward the light emitting plate 66. As a result, the light-emitting layers 72 and 80 absorb ultraviolet rays and emit visible light toward the electronic component 78, and this visible light enters the lens 86 and causes the solid-state imaging device 98 (see FIG. 5) of the imaging device 84 to emit electrons. A projected image of part 78 is formed. The imaging device 84 converts this projected image into a binary signal and outputs it to a control device (not shown). The control device uses the binary signal and the normal image of the electronic component 78 stored in advance in its own memory, that is, the normal electronic component 78 with no bends in the lead wire 82 is held in the normal position. The holding position error and the bending of the lead wire 82 are detected by comparing the binarized signal of the image.

Image 100 of electronic component 78 captured by imaging device 84
An example is shown in FIG. If this image 100 has a holding position error, an angular error Δθ around the center line of the suction tube 78, a deviation ΔX in the X-axis direction, and a deviation Δy in the yltIIi1 direction, the solid-state image sensor 98 is at a different position than when there is no deviation. An image is formed at , and Δθ, ΔX, and Δy are detected based on the positional deviation.

This detection is performed as follows. First, regarding the image 100 of the electronic component, 4
The straight lines I and j of the tree are found. There are various ways to find this straight line, and an example will be explained with reference to the lower side of FIG.

In addition, in FIG. 4, an xy coordinate plane with the origin 0 at the center line -L of the suction tube 76 is assumed, and the center ○' of the image 100 is shifted by ΔX and Δy in the X-axis direction and the y-axis direction, respectively. , and there is an angular error of Δθ. In addition, it is desirable that the straight line be in contact with all the glue wires 82 attached to the lower side at the same time, but since there is usually a slight length error in the lead wire 82, , such a thing cannot be expected. therefore,
They each extend parallel to the y-axis at a certain distance S (this distance is set to a value slightly shorter than half the length of the row of lead wires 82 on the lower side) in both the positive and negative directions from the y-axis. Within a strip area of two trees with a constant width W (the width of this strip area is selected to ensure that about 3 to 5 lead wires are present within the area), a straight line, Two or more lead wires each (to avoid errors caused by only one tree being particularly long) 8
2, and when the straight line L1 is moved downward by a predetermined small distance Δd from that state and no longer touches the lead wire 82 in any strip area, the straight line L1 touches all the leads on the lower side. It is assumed that the line 82 is in contact with the line 82.

First, a straight line L2 is assumed that is parallel to the straight line that touches all of the lead wires 82 on the lower side and is guaranteed to deviate downward from all the lead wires 82 when there is no holding position error in the electronic component 78. , and this straight line L2 is translated upward parallel to the y-axis. In the example of FIG. 4, since the electronic component 78 is held in a state where there is an angular error Δθ in the counterclockwise direction, the above-mentioned upward parallel movement causes the straight line L2 to first become two or more lines (originally (Although the position where the lead wires 82 of the two trees are in contact is searched for, it may be in contact with multiple lead wires 82 at the same time.) It does not touch the lead wire 82. Therefore, from this state, the straight line L2 is translated upward by a certain minute distance Δd, and it is thereby checked whether the straight line L2 touches the Riet line 82 in the right band-shaped region. If they do not touch, the straight line L2 is rotated counterclockwise by a predetermined minute angle Δβ about the intersection with yI+b. As a result, the straight line L2 returns to the state where it does not touch the lead wire 82 in the left band-like region, and from that position further upwards, it comes into contact with two or more lead wires 82 again in the left-hand band-like region. It is moved in parallel until it becomes .

From that position, the straight line L2 is further moved upward by a certain minute distance Δd, and it is checked to see if it comes into contact with two or more lead wires 82 in the right band-shaped region.

Then, if the line L2 does not touch yet, the constant minute angle Δβ
The rotation and the parallel movement by a certain minute distance Δd are repeated. As a result, after the straight line L2 comes into contact with two or more lead wires in the left strip area, a certain minute distance Δ
If it is translated upward by d, the band-shaped region on the right side will also come into contact with two or more lead wires 82 .

The straight line L2 at this time is the straight line L1 that can be considered to be in contact with all the lead wires 82 on the lower side.

The same thing may be done for both the left and right sides and the top side in FIG. 4, and the remaining three straight lines may be found, but for example, for the left side, the straight line L1 is found, and for the right side and the top side, the straight line L1 is found. It is also possible to calculate the straight lines from the positions of the lower and left sides, respectively, and the shape and dimensions planned for the image lOO of the electronic component 78.

In any case, if the four-tree straight line L is found,
Four straight lines wAL located inside by a predetermined distance w&u from these straight lines are found. and,
The tip portion 83 of each lead wire 82 on these straight lines L3
The coordinates of the midpoints A, B, and CD of each side are determined as the average value of the coordinates of the midpoint in the width direction of the image of The center point ○' of the electronic component 78 is determined as the intersection of the straight lines of the book. The X coordinate and the X coordinate of this center point ○' are the y-axis of the electronic component and the deviations ΔX and Δy in the y-axis direction.

The angle error Δθ is the angle that a straight line connecting the midpoints of two opposing sides makes with respect to the straight line L4 representing the position that the straight line should occupy if there is no holding position error in the electronic component 78.

In the above explanation, the simple arithmetic mean of the center position in the width direction of the tip end 83 of the lead wire 82 on each side is the coordinate value of the midpoint A, B, C, D on each side as shown in Table 1. That's true, but strictly speaking that's not the case. Imaging device 84
This is because the imaging direction of the electronic component 78 is tilted with respect to the electronic component 78, so the length of the portion of the electronic component 78 closer to the imaging device 84 is imaged longer than the length of the portion farther from the imaging device 84. This is clear from FIG. If the optical axis of the lens 86 of the imaging device 84 is tilted at an angle α with respect to the vertical line, the tip 83 of the lead wire 82 of the electronic component 78 should be located on the horizontal plane and the horizontal plane where the optical axis intersects with the horizontal plane. Points E and F, which are separated by a distance a, are as if they were point G
, H, but as is clear from FIG. 5, the distance from the optical axis to point G is not equal to the distance b2 to point H, and the distance b2 is is larger than the distance b1. This means that even if the arrangement pitches of the lead wires 82 are all equal, the pitch between the lead wires closer to the imaging device 84 is imaged larger than the pitch between the lead wires 82 farther away, and therefore, the lead wires on each side If the positions of midpoints A, B, C, and D are found as a simple arithmetic average of the positions of the tip portions 83 of 82, these positions can be found as points that are each slightly shifted toward the side closer to the imaging device 84 than they actually are. It happens. Therefore, strictly speaking, it is necessary to correct this deviation, but in reality, the size of the electronic component 78 is sufficiently small compared to the distance from the intersection P to the lens 86, so the pitch between the lead wires 82 is adjusted. The difference is so small that it can be ignored in practical terms, and the midpoint A
, B, C, and D can often be determined by simple arithmetic mean.

Horizontal and vertical bends in lead wire 82 are also detected from image 100 in FIG. That is, the holding position errors ΔX and Δ of the image 100 actually obtained by the imaging device 84
The image with y and Δθ removed is the normal image (lead line 8
2) (an image of the electronic component 78 in the case where there is no horizontal or vertical bending), and checking whether the actual image of each lead wire 82 deviates from the normal image. is carried out.

The lead wire 82 indicated by V in FIG. 4 is a lead wire with a bend. However, since the image 100 represents both the horizontal bending and the vertical bending of the lead wire 83 4 2, it is not possible to determine whether the lead wire 83 4 2 is bent horizontally or vertically. The electronic component 78 can only be determined to be usable if the lead wires are not bent either horizontally or vertically.

Note that the lead wire 82 is bent in both the horizontal and vertical directions, and the tip portion 83 is bent due to these bends.
If the deviations of the images from the normal positions exactly cancel each other out, that is, if the lead 1182 is just bent in the imaging direction of the imaging device 84, the lead wire 82
Although there is a bend, it is determined that there is no bend.

If the amount of bending is large, an unusable electronic component 78 will be attached to the printed circuit board, resulting in a defective product. However, since the possibility of this happening is not that high, the incidence of defective products is practically It never gets high enough to be a problem.

However, in cases where an extremely low rate of defective products cannot be tolerated, or where it is necessary to detect horizontal bends and vertical bends of the lead wire 82 separately, the imaging direction may be tilted. In addition to the imaging device 84, an imaging device whose imaging direction is perpendicular is provided, and the holding position errors ΔX and Δ of the electronic component 78 are calculated based on the image obtained by this imaging device.
y, Δθ, and the horizontal bend of the lead wire 82 are detected, and the tip of the lead wire 82 in the image obtained by the imaging device 84 whose imaging direction is tilted and the image obtained by the imaging device whose imaging direction is perpendicular. It is necessary to detect the vertical bending from the deviation of the image of the portion 83.

Note that when the lead wire 82 is bent in the vertical direction, the image shift of the tip end 83 of the lead wire 82 that is far from the imaging device 84 is larger than the image shift of the tip end 83 of the lead wire 82 that is closer. This is clear from FIG. A point 1. is located at a distance of an open path 'Mc from the intersection P of the optical axis of the lens 86 and the plane where the tip 83 of the lead wire 82 is located. When the tip 83 is located at point J, each point is located at point K.
3" is imaged as if it were located at M, but if the tip 83 is located at points N and Q a distance d above due to the vertical bending of the 5 6 lead wire 82, Since the image is taken as if the points R and S are located at a distance el+e2 from the point P, the lead wire 82 that is far from the imaging device 84 is detected as having a large bend in the vertical direction. Taking this fact into consideration, the reference value for determining whether the wire 82 is bent in the vertical direction to an extent that it cannot be used should be set larger for the lead wire 82 that is farther from the imaging device 84. be.

Furthermore, as is clear from the fact explained earlier with reference to FIG. Strictly speaking, the reference value for determining whether or not is excessive needs to be set larger for the lead wire 82 closer to the imaging device 84.

After detecting the holding position error of the main body 81 and the bending of the lead wire 82 as described above, the electronic component 78 whose lead wire 82 is determined to have no bend that is unusable is moved to the mounting position. However, at this time,
It is moved so that the deviations ΔX and Δy in the chi-axis and y-axis directions are eliminated, and during the movement, the servo motor 60 is driven and the suction tube 76 is rotated to eliminate the angular error Δθ. It can be rotated by the required angle. Therefore, when the suction tube 76 is stopped above the printed circuit board, the printed circuit board 1-1 and the electronic component 78
is a relative position suitable for mounting, and the linear slide 12 is lowered, and the electronic component 78 held by the suction tube 76 is pressed to a predetermined position on the printed circuit board and fixed by adhesive or the like. . In this state, by switching the electromagnetic directional control valve, the suction tube 76 is communicated with the atmosphere, thereby releasing the electronic component 78, and then, when the suction tube 76 rises, the mounting of the electronic component 78 on the printed circuit board is completed. .

Note that the larger the inclination angle in the imaging direction, the larger the pitch shift of the tip portions 87 8 3 when the lead wire 82 has a vertical bend, and the bend can be accurately captured. tip 83
When photographing an image with the camera 88, if the inclination angle is too large, the difference in distance from the imaging device between the distal end 83 that is close to the imaging device and the distal end 83 that is far away from the imaging device becomes large, and the image becomes unclear. Therefore, this inclination angle varies depending on the performance of the imaging device and the size of the electronic component 78, but is 10 degrees to 45 degrees.
The angle is preferably 15 degrees to 35 degrees, particularly preferably 15 degrees to 35 degrees.

In addition, in the above embodiment, the angular error Δθ of the electronic component 78 is
, positional deviation ΔX in the X-axis and y-axis directions.

Δy and the bending of the lead wire 82 were imaged and detected while the electronic component 78 was stopped moving, but it is now possible to image it while the electronic component 78 is moving and detect it.
It may also be detected. In this case, the imaging device has a linear imaging device in which light-receiving elements are arranged in a direction perpendicular to the moving direction of the electronic component 78, and each time the electronic component 78 moves a unit distance, the image obtained by the linear imaging device is This allows us to obtain the entire image as a set.

Furthermore, the light source that irradiates the lead wire 82 with light is not limited to one that irradiates ultraviolet rays, but can also be a direct illumination source or indirect illumination source that is larger than the electronic component and can illuminate the entire component and emits light of other wavelengths. Various light sources can be used.

Furthermore, in the above embodiment, the tubing of the lead cotton is detected based on the image formed by the light transmitted between the lead wires 82, but it is detected based on the image formed by the reflected light. The bend may also be detected by

Another embodiment of the invention is shown in FIGS. 7-15. In this embodiment, images of the tips 83 of the -1 line 82 provided on each of the four sides of the main body 81 of the electronic component 78 are taken every two parallel sides. In this embodiment, the electronic component 78 is taken out from an electronic component supply device (not shown) by an electronic component holding head for taking out, and then
It is placed on the mounting table 110 in the figure, and the mounting table 1101=
The electronic component 78 for mounting is held in the suction tool 114 by an electronic component holding head for mounting (referred to as 90 mounting head by Kawakami), and is transported toward the printed circuit board transport and positioning device 116 provided at the electronic component mounting position. Detection head 11
8 detects the holding position error of the main body 81 and the bending of the lead wire 82.

The supply and installation of this electronic component 78 is described in Japanese Patent Application Laid-open No. 1-1938.
This is the same as the electronic component mounting apparatus described in Japanese Patent No. 97, and the explanation thereof will be omitted.

The detection head 118, as shown in FIG. be placed). As shown in FIG. 9, these slides 128 and 130 are slidably fitted into guides 134 installed in the frame 132 parallel to the y-axis direction (direction perpendicular to the electronic component transport direction). , a nut 138 . ,． They are screwed together at 140. The feed screw 136 has two parts whose screw directions are opposite to each other.
38 and 140 are screwed together. Unfeeding 13
6 are rotatably and axially immovably supported by the frame 132, and timing healds 142, 144. It is connected to a servo motor 148 via a timing heald 146. Thereby, as the servo motor 148 rotates in the forward and reverse directions, respectively, the slides 128 .
Reference numeral 130 denotes horizontal curvature detection devices 120 and 122 . Vertical bend detection devices 124 and 126 are connected to electronic component 78.
The detection devices 120, 122, 124, and 126 are moved close to each other while maintaining a symmetrical relationship with respect to a vertical plane including the conveyance path, and the distance between the detection devices 120, 122, 124, and 126 is determined according to the size of the electronic component 78. adjusted to.

The horizontal failure detection devices 120 and 122 include light emitters 152 and 154 that are attached to the slides 128 and 130 by brackets (not shown) and located above the passage path of the lead wire 82 of the electronic component 78, and the slide 12
8,130 and located on the opposite side of the path of the lead wire 82 from the emitter 1 2 152,], 54.
158. As the light emitters 152 and 154, it is preferable to use one that is equipped with a lens and can focus the visible light of the light emitting element on the passage path of the lead wire, or one that can emit a narrow laser beam. Not essential.

The light emitters 152, 154 and the light receivers 156, 158 are provided in a vertical direction, and as the electronic component 78 is transported, the tip 83 of the lead wire 82 is inserted between the light emitters 152, 154 and the light receivers 156, 158. The receiver 156
, 158 is obstructed, and the amount of light received decreases. The passage of time during the transportation of the electronic component 78 and the light receiver 156 at this time
．． The relationship between 158 and the amount of received light is expressed as shown in FIG. 10, which indicates the existence of a line 82 where the amount of received light decreases, and if there is a horizontal bend in the tip 83, it indicates the shading period when light reception is hindered. As a result, the interval at which the amount of received light decreases becomes longer or shorter than when there is no bend. Receiver 1
The amount of light received at 56 and 158 is supplied to the control device 160 and stored in the memory in association with the time when measurement is started from a predetermined point in time, and is stored in the memory in association with the time when the measurement is started from a predetermined point in time. Tip 8 based on conveyance speed
3 is calculated, and the horizontal bending can be detected by determining the position of the tip 83 in the same way as when taking an image of the tip 83 with a camera.

Vertical bend detection device 124. ], 26 are respectively,
Similar to the horizontal curvature detection devices 120 and 122, light emitters 162 are provided on opposite sides of the slides 128 and 130 across the passage path of the lead wire 82 of the electronic component 78.
, 164 and light receivers 166 and 168, and these light emitters 162164 and light receivers 166 and 168,
It is inclined with respect to the direction in which the lead wires 82 are lined up.

Therefore, the tip 83 of the lead wire 82 is connected to the light emitter 162.
．． 164 and the light receivers 166 and 168, the amount of received light decreases, and the decrease in the amount of received light indicates the presence of the lead wire 82. If the lead wire 82 has a vertical bend, the amount of received light decreases. The timing of the drop is different from that in the case where there is no bend.

3 4 As shown in FIG. 11, the tip 83', which has shifted upward due to the vertical bending of the lead wire, is
(Represented with reference numeral 83) Electronic component 7 is placed in a position that blocks light.
Even if 8 is moved, it still does not block the light,
The electronic component 78 is moved until the tip 83' reaches the position indicated by the two-dot chain line to block the light. In addition, the tip portion 83'' shifted downward blocks the light at the position shown by the dashed-dotted line before the electronic component 78 is moved to the position where it blocks the light when there is no shift, and the tip portion 83'' blocks the light more quickly than when there is no bending. The positional deviation due to the vertical bending of the lead wire 82 can be regarded as a deviation in the light reception timing of the light receiver, in the same way as the horizontal positional deviation due to the horizontal bending. The relationship between and the amount of received light is expressed as shown in FIG.

Note that even if the lead wire 82 is bent in the vertical direction, it will cause the light receiver 15 of the horizontal amount detection device 120, 122 to
6,158, but there is no difference in the light blocking timing when the light reception of 6,158 is prevented,
Since the light emitter 162164 and the light receivers 166 and 168 are inclined in the direction in which the lead wires 82 are lined up, even if the lead wires 82 are bent in the vertical direction, the horizontal tU
Even if there is a t-gap, there will be a shift in the light-shielding timing.

The light receivers 166 and 168 are connected to the control device 160, and the control device 160 stores the amount of light received from the light receiver 166168 in a memory in correspondence with time, and compares the time when the amount of light received and the electronic The amount of deviation of the tip portion 83 is calculated based on the conveyance speed of the component 78, and the amount of deviation in the vertical direction is calculated by subtracting the amount of deviation in the horizontal direction from the amount of deviation. In this embodiment, the light emitters 152, 154, 162
164 serves as a light source, and a light receiver 156 158.1
66, 168 and the control device 160 constitute an imaging device, and an image of the tip 83 of the lead vA82 formed by the light transmitted between the lead wires 82 is taken.

Below, the positional deviation Δ of the main body 81 in the X-axis direction and the y-axis direction
Detection of X and Δy, the angular error Δθ around the inner 5 6 core wire of the suction tool 114, and the detection of horizontal and vertical bending of the lead wire 82 will be described.

The distance between the horizontal direction point detection devices 120 and 122 and the distance between the vertical direction point detection devices 124 and 126 are set in advance according to the size of the electronic component 78, and the distance between the tips 83 of the lead wires 82 on two opposing sides. It is adjusted so that the light hits the center of the length.

In addition, in the suction tool 114, one plane on which the tip end 83 of the lead wire 82 should be positioned is
The electronic component 78 is placed at the same height as the position where the optical axes of the light emitters 152 and 154 of the 22 light emitters 152 and 154 intersect with the optical axes of the light emitters 162 and 164 of the vertical target detection devices 124 and 126.
It is designed to transport. When the electronic component 78 passes over the detection head 118, the tips 83 of each lead wire 82 attached to two sides parallel to the moving direction
The light from the light receivers 156, 158, 166, and 168 is blocked in sequence. Light is emitted from each of the detection devices 120 to 126 after the mounting head 112 adsorbs the electronic component 78 and then the light emitter 1
52,154.162164, when the light emission start position of the short-distance mounting table 110 is reached, and time measurement is started with this position as 0, and the control device 16
0 memory contains the horizontal direction quantity detection device 120122.
, the amount of light received and the time are stored in association with each other for the vertical target detection devices 124 and 126, respectively.

When the lead wires 82 attached to the two sides parallel to the moving direction of the electronic component 78 have passed through the detection head 118, the suction tool 114 is rotated 90 degrees, and the mounting head 112 is moved to the light emission starting position. It is returned to the position of the mounting table 110, and then moved again toward the printed circuit board transport and positioning device 116. As a result, the ends 83 of the wires 82 are attached to the other two sides of the electronic component 78, and the tips 83 of the wires 82 are sequentially attached to the receivers 156, 158, 166.
．． 168 light reception, and data correlating the amount of light received with time can be obtained. In this embodiment, the data necessary for detecting the bending of the entire lead line 82 can be obtained by performing two imaging operations.

After the lead wires 82 on all four sides have passed through the detection head 118, the control device 160 determines whether there is an error in the holding position of the main body 81 and whether the lead wires 82 are bent. First, the holding position error of the main body 81 and the horizontal bending of the lead wire 82 are detected. The amount of received light supplied to the control device 160 is stored in association with the elapsed time from the start of light emission, and also the moving speed of the mounting head 112 and the position of the light receiver at a light shielding position that blocks the light reception of the light receivers 156 and 158. 156, 158) and the light emission start position, the position of each tip 83 ( (horizontal position) can be calculated using the light shielding position as the origin. If this is expressed using an xy coordinate plane, it will be as shown in FIG. 13. Note that the reason why the horizontal axis is the y-axis is because the electronic component 78 will be rotated 90 degrees after this, and when it is mounted, the lead wires 82 on the two sides detected the first time will be located in the y-axis direction. be.

For ease of explanation, assuming that the number of lead wires 82 attached to one side is three, the distance d1 from the light-shielding position of the tip 83 closest to the light-shielding position is At the time 1+ (stored in the memory of the control device 160) until the light shielding position is reached, the rad 11 is attached.
It can be found by multiplying 2 by the moving speed V. Also,
The distance dz between the central tip 83 and the farthest tip,
dz is similarly obtained by multiplying the moving time dz, d3 by the moving speed V. Note that X2 is equal to the distance between the light shielding position and the light emission start position, and the lengths of XaXb+X and Xc are equal to the distances from the center line of the suction tool 114 to the horizontal target detection devices 120 and 122, respectively.

Lead wires 8 attached to the other two sides of the main body 81
2, the distance from the light shielding position when the suction tool 114 is at the light emission starting position can also be determined in the same manner. If the first detection, second detection, and 9 0 are collectively shown on the xy coordinate plane, it will be as shown in FIG. 14.

Based on the detection result of the horizontal position of the tip 83, the holding position error of the main body 81 in the y-axis and y-axis directions, that is, the deviations ΔX and Δy in the X-axis direction and the y-axis direction with respect to the suction tool 114 are determined. Calculated. First, as shown in FIG. 13, the average positions A, B, C, and D in the horizontal direction of the tips 83 on each side of the main body 81 correspond to the midpoints of each side of the main body 81, and The straight lines Ls and L6 connecting the average positions each pass through the center of the main body 81, and based on the assumption that their intersection is the center point of the main body 81, the coordinates (x) of the center position O' of the main body 81.

yo) is required. Then, by comparing the coordinate value of the center position ○' of the main body 81 with the coordinate value 0 (x, , 3'a) when the suction tool 114 is located at the light emission starting position, the suction tool of the main body 81 can be found. Curves Δχ and Δy in the X-axis direction and the y-axis direction with respect to 114 can be determined.

Further, an angular error Δθ, which is a holding position error in the rotational direction of the main body 81, is determined from the y-axis and the inclination of the two straight lines with respect to the y-axis.

These holding position errors of the main body 81 will be corrected later, so
Tip portion 83 of each lead wire 82 when this modification is performed
The position is determined based on the detection result of the horizontal position. Then, this obtained result and each tip 83
(the position where the tip portion 83 is expected to be located when the suction tool 114 is located at the light emission start position with the light shielding position as the origin) is compared, and all the tip portions 83 are
If the amount of deviation of the position from the planned position is within a certain range,
It is determined that the lead wire 82 does not have any horizontal bending exceeding the reference amount and is mounted on the printed circuit board, but if even one of the lead wires 82 exceeds the above-mentioned certain range, the electronic component 78 is discarded.

Next, determination of vertical bending of the lead wire 82 will be described. The amount of light received from the light receivers 166 and 168 of the vertical gap detection devices 124 and 126 is stored in the control device 160 in association with the elapsed time from the start of light emission. Since the moving speed of the radar 112 is known, first, the moving distance from when the suction tool 114 reaches the light emission starting position to when each tip end portion 83 obstructs light reception is calculated. As described above, the deviation in the light reception timing of the light receivers 166 and 168 of the vertical bending detection devices 124 and 126 is also caused by the holding position error of the main body 81 and the horizontal bending of the lead wire 82. Therefore, the moving distance of the tip portion 83 when the holding position error of the main body 81 is corrected is determined,
This calculated result and the planned movement distance of each tip 83 (the light emitting device 152 of the horizontal target detection device 120, 122,
154 optical axis and vertical bend detection devices 124, 126
The intersection point with the optical axis of the light emitters 162 and 164 is the origin, and the distance between the origin and the position where each tip 83 is expected to be located when the suction tool 114 is located at the light emission start position) are compared, and the amount of deviation from the planned travel distance is determined. This amount of disconnection still includes the amount of disconnection due to horizontal bending of the lead wire 82. Therefore, the deviation amount of the tip portion 83 determined by the horizontal direction target detection device 120, 122 is compared with the vertical direction bending detection device 124,
By subtracting from the amount of deviation determined based on the detection result of 126, the amount of deviation only in the vertical direction is determined.

For example, as shown in FIG. 15, if the tip 83 is bent both horizontally and vertically and is in the position indicated by the tip 83', the movement calculated based on the detection of the vertical bend detectors 124 and 126. The amount of distance deviation is f. Further, the amount of deviation calculated based on the detection by the horizontal direction target detection devices 120 and 122 is g, and the amount of deviation based on the vertical direction bending is h=f−g, and this h
It is determined whether or not the tip portion 83 has a bend exceeding an allowable amount in the vertical direction depending on whether or not the amount is within a certain range. If the amount of disconnection is within a certain range, the lead wire 8
It is determined that there is no bend in the vertical direction exceeding the reference amount in the electronic components 78, and the electronic components 78 are mounted on the printed circuit board. However, if even one electronic component 78 exceeds the above-mentioned certain range, that electronic component 78 is discarded.

After detecting the holding position error of the main body 81 and detecting the bending of the lead wire 82 at step 3 4 , the lead wire 8
The electronic components 78 that are determined to have no bending exceeding the reference amount are transported to the printed circuit board transport and position device 116.

During this transportation, the holding position error of the main body 81 is corrected, and the electronic component 78 is mounted on the printed circuit board.

Note that if a bend exceeding an allowable range is detected in the horizontal direction bend detection of the lead wire 82, the electronic component 78 may be discarded without calculating the vertical bend.

Furthermore, in the embodiments shown in FIGS. 7 to 15, the lead wire 82 is irradiated with light one tree at a time, and the inclination angle of the vertical bend detection devices 124 and 126 is increased. Also, in the embodiments shown in FIGS. 1 to 6, images of all the lead wires 82 are not blurred depending on the distance between the lead wires 82 and the imaging device 84, as in the case where the camera 88 obtains images of all the lead wires 82 at once. do not have. Therefore, in this case, it is desirable that the inclination angle is between 30 degrees and 75 degrees.
It is particularly desirable that the angle be 45 degrees to 75 degrees.

Furthermore, in each of the above embodiments, the imaging device 84 and the vertical bend detection devices 124, 126 are tilted, and the imaging direction is tilted in the direction of the main body of the electronic component or the direction in which the lead wires are arranged. You may let them.

In addition, the present invention can be implemented in Model B with various modifications and improvements based on the knowledge of those skilled in the art without departing from the scope of the claims.

[Brief explanation of drawings]

FIG. 1 is a front view (partially in section) of an electronic component holding device having a lead wire gap detection device according to an embodiment of the present invention. FIG. 2 is a plan view of an electronic component whose lead wires are bent by the detection device, and FIG. 3 is a side view. FIG. 4 is a plan view showing an image of the electronic component taken by the imaging device of the detection device. FIG. 5 is a diagram illustrating the position of the image of the lead wire connected to the solid-state image sensor of the imaging device, and FIG. 6 is a diagram illustrating the position of the image when the lead wire has a vertical bend. be. FIG. 7 is a diagram schematically showing an electronic component mounting apparatus having a gap detection device between lead wires, which is another embodiment of the present invention. FIG. 8 is a perspective view showing the lead edge bending detection device, and FIG. 9 is a side view. Figure 10 shows
7 is a graph showing the relationship between the amount of light received by the light receiver of the horizontal direction bending detecting device of the lead edge bending detecting device and time. 1st
FIG. 1 is a diagram illustrating the principle of bend detection by the vertical bend detection device of the lead edge bend detection device. FIG. 12 is a graph showing the relationship between the amount of light received by the light receiver of the vertical bend detection device and time. FIG. 13 is a diagram illustrating calculation of the horizontal position of the tip of the lead wire based on detection by the horizontal direction overshoot detection device, and FIG. 14 is a diagram showing the detection of the holding position error of the main body of the electronic component with respect to the suction tool. This is a diagram. FIG. 15 is a diagram illustrating detection of vertical bending of a lead wire. 66: Light emitting plate 81: Main body 83: Tip part 118: Detection head 78: Electronic component 82: Riet wire 84: Imaging device 20 124° 52 56 162° 66 22 26 54 58 64 68 Horizontal direction amount detection device Vertical direction bending Detection device Light emitter Light receiver 160 Light emitter Light receiver 2 Control device

Claims (2)

[Claims] (1) A light source that irradiates light onto the lead wires of an electronic component that includes a number of lead wires protruding from a main body, each tip of which is positioned on one plane; and a side opposite to the light source with respect to the lead wires. established in
An imaging device that photographs an image of the tip of the lead wire formed by light transmitted between the lead wires, and whose imaging direction is tilted with respect to the direction in which the lead wires are lined up, and an image taken by the imaging device. A lead wire bend detection device for an electronic component, comprising: bend detection means for detecting bends in the lead wires based on images of the tips of the plurality of lead wires. (2) A light source that irradiates light onto the lead wires of an electronic component consisting of a large number of lead wires whose tips should be located on one plane and protrude from the four sides of a rectangular main body. Formed by the light irradiated by the light source. An image of the entire electronic component is captured by one imaging operation, and an imaging device whose imaging direction is inclined with respect to all four sides of the main body of the electronic component; A lead wire bend detection device for an electronic component, comprising: bend detection means for detecting bends in the lead wires based on images of the tips of the plurality of lead wires.