JPH0350417B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a device for detecting and removing defective electronic components such as IC elements, and in particular to an electronic component consisting of a base body and a plurality of leg pieces connected to both sides of the base body. The present invention relates to a device that detects whether the condition of the legs is good or bad while traveling on an inclined conveyance path, and removes defective products.

<Prior art> An electronic component consisting of a base and a plurality of legs connected to both sides of the base is inserted into a plurality of holes provided in advance at corresponding locations on a circuit board, etc., and the electronic component is inserted into the circuit board. In recent years, this type of insertion work has been performed using high-speed automatic insertion devices. In this case, the mutual positional relationship of the multiple pores on the circuit board is determined in advance, so if some of the legs of the electronic component are bent, it may be difficult to insert the electronic component onto the circuit board. This may result in a final product with some electronic components missing, or
This causes inconveniences such as having to interrupt work and remove defective products from the line.

Therefore, before fixing electronic components on the circuit board,
It is necessary to check the connection state of the legs and remove from the line those legs that are too bent to be inserted into the holes on the circuit board.

Conventionally, the bending of the leg pieces in the front-rear direction, that is, the alignment direction, was performed by applying a light beam to each surface of a plurality of leg pieces.
The reflected light is detected, and the image is compared with the positional relationship of the legs of a normal electronic component. If the two match or if the error is slight and there is no problem in fixing the electronic component on the circuit board. Some products were considered acceptable, and others were considered defective and removed from the line.

In addition, in order to detect bending in a direction perpendicular to the alignment direction of the leg pieces of an electronic component, a light beam is irradiated from a light source such as a floodlight installed on one side of the leg piece alignment direction, and the other side is The state of the leg is detected as a two-dimensional image by capturing the shadow of the leg with a detection unit such as an imager installed on the side, and the condition of the leg is detected as a two-dimensional image by comparing this image with an image of a normal leg. The idea is to detect abnormalities in pieces.

<Problems to be Solved by the Invention> However, in the method described above, depending on the surface condition of the leg piece, the amount of reflected light varies greatly, and even if the leg piece is in a normal position, the reflected light There is a risk that products that should have passed should be removed from the line without being able to detect them. Moreover, in order to detect a two-dimensional image, a two-dimensional image sensor is required, which poses a problem of complicating the device and increasing costs.

In addition, when detecting bending in the alignment direction of the leg pieces, the light source or detection unit occupies a position aligned with the alignment direction of the leg pieces, which becomes an obstacle when transporting electronic components, and may cause the light source or detection unit to move. In this case,
This makes it difficult to speed up the process of inspecting a large number of electronic components.

Moreover, in order to capture images of the leg pieces from the direction in which the leg pieces are aligned, the leg line has a depth, so
This requires an optical system with a large depth of focus or a strictly parallel light beam from a laser beam, which is disadvantageous in that it requires multiple devices and is expensive.

In view of these drawbacks of the prior art, the main object of the present invention is to detect bending of a leg in either direction relatively easily, regardless of the surface condition of the leg. It is an object of the present invention to provide a device which can operate at high speed, reliably detects only defective products, and removes the defective products from the line.

<Means for Solving the Problems> According to the present invention, an object of the present invention is to detect defects in the legs of an electronic component having a plurality of legs aligned along both sides of a base body. An inclined conveyance path that allows the electronic components to be conveyed by gravity, an escapement means provided on the upstream side of the conveyance path to feed out the electronic components one by one, and detection of bending of the legs in the front and rear direction. a first detection stage that detects bending of the leg in the left-right direction; a second detection stage that detects bending of the leg in the left-right direction; and electronic components in which an abnormality is detected in at least one of the first and second leg detection stages. In the device for detecting a defect in a leg of an electronic component, the first detection stage directs a light beam from between the rows of legs on both sides of the base toward the leg. substantially parallel to the bottom surface of the base,
and one-dimensional images of two or more portions that are different in the length direction of the leg by a means for emitting light substantially perpendicular to the alignment direction and a light beam transmitted to the outside of the leg. Compare the relative positions in the alignment direction of the two or more parts from the one-dimensional image with a detecting means to determine whether the distance between adjacent leg pieces in the alignment direction is within an allowable range. The second detection stage transmits a light beam from between the rows of legs on both sides of the base substantially parallel to the bottom surface of the base and in the direction in which the legs are aligned. a light projecting means for projecting light obliquely to the leg; and a means for detecting one-dimensional images of two or more different parts in the length direction of the leg using the light beam transmitted to the outside of the leg. Comparing the relative positions of the two or more parts in the alignment direction from the one-dimensional image to determine whether the spacing between adjacent leg pieces in the alignment direction is within an allowable range. This is achieved by providing a defect detection device for a leg piece of an electronic component, which is characterized by having a means.

<Operation> According to such a configuration, three-dimensional bending of the leg piece can be detected by the two-stage detection stage of the optical axis orthogonal to the alignment direction of the leg piece and the inclined optical axis.
The light source or the detection section can be provided at a position that does not interfere with the transport path of electronic components. The presence or absence of deformation of the leg piece can be determined based on the presence or absence of a relative shift in the imaging positions of two or more parts in the length direction of the leg piece, or the shift in the interval between images of adjacent leg pieces. .

<Embodiments> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an electronic component consisting of an IC element 1 having normal leg pieces, in which a plurality of leg pieces 3 and 4 are provided on both sides of a molded base 2, respectively. A notch 5 for direction identification is provided at the front end of the base body 2. The base body 2 has a separation line 6 corresponding to the joint surface of the mold, and the position of the leg piece cannot be determined with reference to the front and rear end surfaces 7 of the IC element 1 because of burrs generated in this part. The device according to the invention can detect the bending of the legs 3, 4 in the left-right and front-back directions as shown by imaginary lines.

FIG. 2 is a schematic illustration of a first embodiment of the device according to the invention.

The casing 11 has a pentagonal cross section in the front-rear direction, and the upper side surface 12 and lower side surface 13 of the casing 11 are parallel to each other,
and sloping. Each of the side surfaces 12 and 13 is provided with an IC element introduction hole 15 and an IC extraction hole 16 through which the IC element 1 consisting of the base body 2 and the leg pieces 3 and 4 can pass. A magazine (not shown) is attached to the outside of the introduction hole 15 and the extraction hole 16, and the opening of the cylindrical body 14 capable of accommodating a plurality of IC elements 1 in one row is connected to the introduction hole 15 and the extraction hole 16, respectively. It is designed so that it can be sequentially aligned with the extraction hole 16. A conveyance path member 19 is installed between the introduction hole 15 and the extraction hole 16, so that the IC element 1 can run on the conveyance path member 17 by its own weight.

An escapement device is provided at the upstream end of the conveyance path member 17, and includes two air cylinders 18 and 19 arranged one behind the other. These air cylinders 1
8 and 19 are operated alternately to sequentially send out the IC elements 1 to the downstream side of the conveyance path. A notch sensor 20 is provided between these air cylinders 18 and 19, and by detecting the notch 5 of the IC element 1, the forward and backward directions thereof can be identified. This notch sensor 20 may be of an ultrasonic type or an optical type. It is also possible to identify the front and rear directions of 1.

Conveyance path member 1 on the downstream side of the escapement device
7 constitutes a reversible portion 21, to which a rotating shaft 23 of a pulse motor 22 provided below is fixed, stopped by an air cylinder 25, and fixed on the reversible portion 21 by an air cylinder 24.
The IC element 1 is arranged so that its front and rear sides can be reversed.
When the IC element is fixed by the air cylinder 24, the air cylinder 25 is pulled up, and the piston rod 24a of the air cylinder 24 is connected to the pulse motor 22.
Since the IC element 1 is aligned with the rotation axis 23 of the IC element 1, the reversal of the IC element 1 is performed smoothly.

A first leg defect detection stage is provided downstream of the reversing portion 21 to detect bending of the leg in the alignment direction, that is, in the front-rear direction. This leg defect detection stage is
Consisting of two leg defect detection devices arranged symmetrically on the left and right sides of the conveyance path member 17, each of which can simultaneously detect bending in the alignment direction of the left and right legs 3 and 4 of the base body 2. . Above the downstream side,
An air cylinder 26 for temporarily stopping the IC element 1 is provided at the same portion.

FIG. 3 is an explanatory diagram showing details of this leg defect detection device.

A plurality of leg pieces 3 and 4 protrude from both left and right sides of the base body 2 having a flat rectangular cross section, and are each bent downward near the base end. IC element 1 is
Triangular prisms 27 and 2 are placed on the left and right sides of the lower part of the conveyance path 10, which are placed so as to straddle the conveyance path 17 and are located between the rows of the leg pieces 3 and 4 on both the left and right sides.
8 are arranged.

A light source 29 is installed directly below the prisms 27 and 28, and the light rays from the light source 29 pass through the prisms 27 and 2.
8, the direction is changed into two groups of light rays, each pointing in the left and right directions. Since this embodiment is bilaterally symmetrical, only the light rays traveling in the right direction in FIG. 3 will be described below.

A part of the group of light rays traveling to the right hits the leg piece 4 and is blocked, and the rest travels straight to the right of the leg piece 4, and is diverted downward in FIG. 3 by the reflecting mirror 30. The lens 31 allows the image sensor 32
Tie a statue on top. This image becomes a silhouette image in which only the portion where the leg piece 4 is present is dark, as shown in FIG. 4a, for example. The sensitive portion 32a of the sensor 32 is linear and captures a one-dimensional image of the portion indicated by the line () in FIG. 3a, for example.

A pulse motor 33 having a built-in ball screw is connected to the sensor 32, and the pulse motor 33 moves the sensor 32 left and right as shown by the imaginary line in FIG. 3, and at the same time the sensing part 32a also changes its position. become. A light beam having a different path than before the movement is incident on the moved sensing section 32a and forms an image. This image is a one-dimensional image corresponding to the lower part of the leg piece 4 in FIG.
This is the image of the part indicated by the line ( ) in the figure.

By scanning the contrast image on the sensing section 32a in correspondence with a clock pulse of a certain prescribed frequency, a pulse signal corresponding to the captured image can be obtained, as shown in FIG. 4b. Fourth
The waveforms () and () in figure b are the lines () respectively.
This corresponds to (), and since the pulse signals of both parts match and the pulse period p of each part is constant, there is no defect such as bending or chipping in the leg piece 4 of the IC element 1 that is the object of detection. It shows that it was

The leftmost leg 4a shown in Fig. 5a is normal, but the two central legs 4b and 4c are bent, and as shown in Fig. 5b, the corresponding pulse waveforms This is detected as a mismatch in the pulse timing of the corresponding parts. The right end leg piece 4d in FIG. 5a is bent at the proximal end and straight from the middle part to the free end. Therefore, as shown in Figure 5b,
Although the pulse timings of both parts match, the interval p' between adjacent pulses is different from the period p, and the bending of the leg is also detected. 6th
The legs 4 shown in the figure are all bent in the same direction. Therefore, although the interval p between pulses is constant, a constant deviation q occurs between the pulse waveforms of portions () and ().

In this way, by comparing the pulse waveforms of the two parts obtained by scanning twice, the results are shown in Figure 4a ().
If the timing coincidence of the pulses and the interval between adjacent pulses according to the images of both parts shown in () are within the permissible range, it can be seen that all the leg pieces are normal. Therefore, this IC element is a passed product and can be used as a final product as is. At this time,
Since the defective leg piece is determined by comparing two pulse waveforms and determining the pulse interval, there is no need to position the base body, and there is no problem even if there is a burr on the front end surface of the IC element.

A second leg defect detection stage is disposed downstream of the first leg defect detection stage. This is for detecting the bending of the legs 3 and 4 in the left and right direction, and consists of two leg defect detection devices arranged one behind the other on the left and right sides of the conveyance path member 17, respectively. The bending of the leg in the left and right direction can be detected back and forth. Above the downstream side,
An air cylinder 4 for temporarily stopping the IC element is provided at the same portion.

FIG. 7 is an explanatory diagram showing details of this leg defect detection device.

A plurality of leg pieces 3 and 4 protrude from both left and right ends of the base body 2 having a flat rectangular cross section, and are each bent downward near the base end. IC element 1 is
A reflecting mirror is placed at an angle of about 45° with respect to the conveyance surface at the bottom of the conveyance path 17, which is placed so as to straddle the conveyance path 17, and is located between the rows of legs 3 and 4 at both left and right ends. 35 are arranged.

Another reflecting mirror 36 is installed diagonally below the reflecting mirror 35, and the light beam from the light source 37 is directed to the reflecting mirrors 36, 3.
5, the direction is changed to form one group of light rays pointing to the right in FIG.

A part of this group of rays is part of leg piece 4 ()
The rest of the light travels straight to the right of the leg 4, is diverted downward in FIG. 7 by the reflecting mirror 38, and is focused on the image sensor 40 by the lens 39. This image becomes a silhouette image in which only the portion where the leg piece 4 is present is dark. sensor 4
The sensing section 40a of No. 0 has a linear shape and captures a one-dimensional image of a portion () where the leg piece 4 intersects with a certain horizontal plane.

A pulse motor 41 having a built-in ball screw is connected to the sensor 40, and the pulse motor 17 moves the sensor 40 left and right as shown by the imaginary line in FIG. 7, and at the same time the sensing part 40a also changes its position. become. A light beam having a different path than before the movement is incident on the moved sensing section 40a and forms an image. This image is a one-dimensional image of the portion () of the leg piece 4 in FIG. 2 that intersects with different horizontal lines.

8 and 9 are a side view and a plan view of the embodiment of FIG. 7. FIG. The first reflecting mirror 36 has an angle of approximately 58 degrees with respect to the conveying surface, and the light reflected thereon is reflected on the second reflecting mirror 35 and directed in the horizontal direction. Therefore, the light emitted from the light source 37 provided at the front side in the alignment direction and diagonally downward at the outer position of the leg row of the IC elements 1 is the first,
Its direction is changed by second reflecting mirrors 36 and 35,
Eventually, the beams will cross the leg rows with a group of rays pointing horizontally and diagonally backward.

As described above, according to the present invention, since the light rays passing through the leg array in an oblique direction are captured, the distance between the legs appears as a difference in image size in the image formed on the sensing section. That is, as shown in FIG. 10, each leg piece is perceived as an image whose size is proportional to the angle formed by the straight line connecting the point P representing the center position of the lens and the edge of each leg piece in the alignment direction. An image is formed on the portion 40a. Therefore, if the leg pieces are numbered 4 ₁ to 4 ₄ in order of distance from point P, and the above-mentioned angles are set to a ₁ to a ₄ , then a ₁ < a ₂ < a ₃ < a ₄ . A similar relationship holds true for the intervals b ₁ to _{b 3} between the leg pieces.

Therefore, when the bright and dark image on the sensing section 40a is scanned in correspondence with a clock pulse of a certain specified frequency, two waveforms as shown in FIG. 11 are obtained, and each leg piece 4 ₁ to 4 ₄ The corresponding pulse width A ₁ ~
A ₄ is proportional to the corresponding angle a ₁ -a ₄ . Here, the second reflecting mirror 35, the IC element 1, and the lens 3
9. Since the relative position of the sensing part 40a is fixed mechanically, the effect of perspective difference from point P to the position of each leg piece can be easily corrected based on the geometric relationship of each part. In this way, the accuracy of determining the bending of the leg can be improved.

The waveform diagram shown in FIG. 11 was obtained from a normal leg, and the pulse timings obtained for the two parts () and () of the leg 4 set at intervals in the vertical direction are They match, and the pulse intervals are within a predetermined tolerance.

In FIG. 12, the leg piece ₄₁ is bent inward,
The outward bending of the legs ₄₃ is detected as a timing mismatch between the pulses obtained from the two positions. In the waveform shown in FIG. 13, the timings of all the pulses corresponding to each of the legs 4 ₁ to 4 ₄ match, but there are some where the intervals between adjacent pulses are not appropriate, and It can be seen that even though leg 4 ₃ is straight in the vertical direction, it protrudes more outward than the other leg pieces.

On the downstream side of the second leg defective detection stage, a defective product removal stage is provided for eliminating IC elements having defective leg pieces. An air cylinder 42 is provided for temporarily stopping the operation.

A part of the conveyance path in the same part is the conveyance path member 17.
The downstream end of the pivot member is pivoted by a pivot shaft 44, and the operating end of an air cylinder 45 is connected to the lower part of the intermediate portion of the pivot member. There is. Therefore, the pivot member 43 can be rotated downward about the pivot shaft 44 by the air cylinder 45 below.

The detection results obtained by the sensors 32 and 40 of each leg defect detection device are aggregated by the controller 46,
If the front and back of the IC element are reversed, the pulse motor 22
is activated to reverse the direction of the IC element, and if even one abnormality is recognized in the detection results of the sensors 32 and 40, the air cylinder 45 is activated to pivot the IC element with the defective leg. It is removed from the device by means of member 43.

In short, the IC element 1 housed in the cylindrical body 14
is guided by its own weight from the introduction hole 15 to the conveyance path member 17 in the casing 11 and travels on the conveyance path member 17. During this time, the air cylinder 18 temporarily stops at a predetermined position on the conveyance path member 17, the front and rear are identified by the notch sensor 20, and if the direction is reversed, the reversing member 21 optimizes the front and rear direction, and the first The connection state of the legs 3 and 4 is checked by the second leg defect detection stage.

The leg piece 3 is detected by the first and second leg defect detection stages.
4 is detected in any of the front, rear, left, and right directions, the controller 46 causes the air cylinder 4 to bend.
5 is activated and when the IC element 1 with the bent leg piece is placed on the pivot member 43, the pivot member 43 is rotated downward as shown by the imaginary line to remove the defective product.
IC elements are removed from the line. The IC element 1 for which no abnormality was detected in the leg pieces 3 and 4 is attached to the pivot member 4.
3, the air cylinder 45 does not operate, and the product passes through the take-out hole 16 and is stored in the lower cylindrical body 14 as an acceptable product.

<Effects of the Invention> The present invention allows an electronic component to travel by its own weight on a conveyance path member provided with a displacement detector capable of detecting displacement of a leg, and when displacement of a leg is detected,
Based on the detection, the electronic component whose displacement has been detected is removed from the conveyance path member. Further, reflected light is not used to detect the displacement of the leg, and a portion of the detection device does not protrude onto the conveyance path of the detection target. Therefore, according to the device based on the present invention, it is possible to automatically detect whether the condition of the leg of an electronic component is good or bad and remove defective products from the line, regardless of the surface condition of the leg. Since electronic components are often mass-produced, being able to inspect them at high speed and with high precision has an extremely large economic effect.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the electronic component showing the bending of the leg pieces using imaginary lines. FIG. 2 is a schematic explanatory diagram showing an embodiment of the apparatus based on the present invention. Figure 3 is the first
It is an explanatory diagram showing a detection stage of. 4 to 6 are plan views showing silhouette images formed on the image sensor. 4 to 6 are waveform diagrams showing the output waveforms of the image sensors corresponding to the respective images. FIG. 7 is an explanatory diagram showing the second detection stage. 8 and 9 are a side view and a plan view, respectively, of essential parts of the embodiment shown in FIG. 7. FIG. 10 is an explanatory diagram showing the size relationship of corresponding leg images depending on the distance difference between the legs. 11th
13 are waveform diagrams of signals obtained from the image sensor. 1...IC element, 2...substrate, 3, 4...leg piece, 5...
Notch, 6... Separation line, 7... End face, 11... Casing, 12, 13... Side surface, 14... Cylindrical body, 15... Introducing hole, 16... Taking out hole, 17... Conveying path member, 18,
19...Air cylinder, 20...Notch sensor, 21
...Reversing member, 22... Pulse motor, 23... Rotating shaft, 24-26... Air cylinder, 27, 28... Prism, 29... Light source, 30... Reflector, 31... Lens, 32... Sensor, 32a... Sensing unit, 33...Pulse motor, 34...Air cylinder, 35, 36...Reflector, 37...Light source, 38...Reflector, 39...Lens, 40...Sensor, 40a...Sensing section, 41...Pulse motor, 42...Air cylinder, 43... Pivot member, 44... Pivot, 45... Air cylinder, 46... Controller.

Claims (1)

[Claims] 1. To detect a defect in a leg of an electronic component having a plurality of legs aligned along both sides of a base,
An inclined conveyance path that allows the electronic components to be conveyed by gravity; an escapement means provided on the upstream side of the conveyance path for feeding out the electronic components one by one; and detection of bending of the leg in the front-rear direction. First thing to do
a detection stage, a second detection stage for detecting bending of the leg in the left-right direction, and elimination for eliminating electronic components in which an abnormality is detected in at least one of the first and second detection stages. In the device for detecting a defect in a leg of an electronic component, the first detection stage directs a light beam from between the rows of legs on both sides of the base toward the leg, The length direction of the leg piece is different depending on the means for irradiating the light so as to be substantially parallel to the bottom surface and substantially perpendicular to the alignment direction, and the light beam transmitted to the outside of the leg piece. means for detecting a one-dimensional image of two or more parts;
means for comparing the relative positions of the two or more parts in the alignment direction to determine whether or not the spacing between adjacent ones of the plurality of leg pieces in the alignment direction is within a permissible range; a second detection stage is a light projecting means that makes a light beam enter between the rows of legs on both sides of the base substantially parallel to the bottom surface of the base and obliquely with respect to the alignment direction of the legs; The length direction of the leg piece varies depending on the light beam transmitted to the outside of the leg piece.
means for detecting a one-dimensional image of two or more parts; and a means for detecting a one-dimensional image of two or more parts, and comparing relative positions of the two or more parts in the alignment direction from the one-dimensional image to determine the alignment direction of adjacent ones of the plurality of leg pieces. A defect detection device for a leg piece of an electronic component, characterized in that the device has a means for determining whether or not the interval between the legs is within an allowable range.