JPH0460201B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for detecting bending of each pin in a component having a plurality of pins such as an IC element or an IC socket. The invention relates to a method capable of detecting.

<Prior Art> In recent years, automatic insertion devices have been increasingly used when mounting electronic components on circuit boards. Automatic insertion devices are capable of inserting various electronic components into boards automatically and at high speed. Electronic components inserted into the board are soldered and completed, but if the legs, or pins, of an electronic component such as an IC are bent, the pins must be inserted into the specified holes in the board. Instead, the board will be soldered as is, and the entire board will be defective. Therefore, it is desirable to inspect the bent pins of electronic components to be inserted into the board in advance, but automatic insertion equipment operates at high speed and is an expensive device, so it is difficult to detect such bent pins. Preferably, the device is capable of inspecting pin bending at high speed so as to maintain the operating rate of the automatic insertion device.

<Problems to be solved by the invention> In view of these demands, the main purpose of the present invention is to
It is an object of the present invention to provide a method for quickly and accurately inspecting pin bending in an element having a plurality of pins.

<Means for Solving the Problems> An object of the present invention is to provide a method for detecting bending of a plurality of pins that extend on a certain reference plane and are to be aligned parallel to each other, A visual sensor that irradiates each of the plurality of pins with a light ray along a predetermined plane that extends along the alignment direction of the plurality of pins and intersects the reference plane, and has a light receiving surface that faces the reference plane. A light image on each pin is captured by reflected light at an angle different from the incident angle of the light beam, and is captured on the visual sensor with respect to a predetermined reference position in the alignment direction and/or extension direction of the pins. This is achieved by providing a method for detecting pin bending, which is characterized by determining pass/fail based on the positional deviation of an optical image.

<Operation> In this way, each pin is irradiated with a light beam along a plane that intersects at a certain angle with the plane on which the pins are arranged, and each pin is illuminated from a position different from the light source in the direction in which the pins extend. When the optical images tied above are observed with a visual sensor, if the pin is bent, there will be a shift in the positions of the optical images on the visual sensor.If you compare this shift with a predetermined reference range, you can determine the position of the pin. The presence or absence of bending can be easily determined. Furthermore, if light is emitted in a planar shape and the reflected light is captured by a one-dimensional image sensor array, bending in two directions can be inspected simultaneously by scanning the light source or image sensor up and down once. I can do it.

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

FIGS. 1 and 2 show IC elements to be tested in this embodiment. This IC element has a total of 14 pins, including seven pins extending in the first direction, the up and down direction, and aligned in the second direction, the front and back direction. One pin 2 is bent outward, another pin 6 is bent inward, and still another pin 4 is bent in the front-rear direction. If the pins are bent in this way, when trying to insert this IC element 10 into the board, the bent pins 2, 4, and 6 will not be inserted into the holes provided in the board, and the entire board will be damaged. This causes the product to be of good quality.

Therefore, it may be possible to inspect from the side using an image recognition device, but in that case, although pins bent in the front-back direction like pin 4 can be easily detected, items bent in the left-right direction like pins 2 and 6 can be easily detected. Bent objects are generally difficult to detect. This is because the image recognition device must have the ability to discriminate depth.

It is conceivable to use an image recognition device to identify bent pins from the direction of the end of the element, but as mentioned above, it is difficult to identify pins that are bent in the front-rear direction like pin 4. Alternatively, it is difficult to detect pins that are bent outward because of the large distance difference.

FIG. 3 is an explanatory diagram showing an embodiment of the method for inspecting pin bending based on the present invention. First, the IC element 10 is positioned using a predetermined jig 40, and pin 1 is
Planar light 30 that is parallel to the alignment direction of ~7 is irradiated obliquely to the extending direction of the pins. This planar light 30 may be obtained by refracting a light source obtained by a laser into a planar shape using a cylindrical lens or the like.

The image sensor 20 is provided at a position where its light-receiving surface faces a predetermined reference plane on which the pins 1 to 7 should align and extend, that is, on the side of the pins,
A planar light 30 is projected onto the pins 1 to 7 so that spots of light focused on the pins can be detected. The image sensor 20 may be a linear image sensor array. This image sensor 20 is driven by a drive mechanism (not shown) in the vertical direction on a plane that faces substantially parallel to the reference plane on which the pins extend, as indicated by arrow A.

The light spots formed when the pins 1 to 7 are irradiated with the planar light 30 will be detected as light spots aligned in a line if all the pins are not bent. In other words, as shown in Fig. 4, these light spots are located at appropriate positions in the length direction of the pins, relative to _the reference straight line _Y0 drawn across each pin. The points are detected at the intersections with the lines X ₁ to _{X 7} drawn at equal intervals in the direction orthogonal to each other, that is, the reference line in the extending direction of each pin (spots 11, 12a, 13, 14a, 15,
16a and 17). In other words, for a pin bent outward like pin 2, the light spot 12 will be located at a location spaced upward from the straight line _Y0 .
For a pin bent inward like pin 6, a light spot 16 is detected in a portion spaced downward from _Y0 . Further pin 4
For a pin bent in the front-rear direction as in the figure, the light spot ₁₄ is detected at a point spaced from the straight line

Since there is a correspondence relationship as described above between the bending of the pin and the spot of light detected by the image sensor 20, the allowable area in the detected image of the image sensor 20 that corresponds to the allowable range of the bending of the pin is set, and when the light spots 11 to 17 deviate from the allowable range set in this manner, it becomes possible to determine that the bending of the pin is greater than the allowable range. For example, in Fig. 4, when any one of the light spots 11 to 17 deviates above the straight line _Y1 or below the straight line _Y2 , the horizontal bending of each pin is greater than the allowable value. When the light spot does not overlap each of the straight lines _X1 to _X7 , it can be determined that the bending of the pin in the front-rear direction is equal to or greater than the allowable value.

FIG. 5 shows another embodiment according to the invention. In the embodiment described above, the image sensor 20 is moved vertically and parallel to scan a predetermined field of view to detect a spot of light, while the image sensor 20 is fixed and the image sensor 20 is Shape light 30 with arrow B
By vertically moving the pin in parallel as shown in the figure, the bending of the pin can be detected in the same manner as in the embodiment described above.

Although the present invention has been described above with reference to specific embodiments, various embodiments other than those described above are possible. For example, in the above embodiments, a surface light beam is used as the incident light beam, but the same purpose can also be achieved by scanning a laser beam within such a surface. In addition, image sensors are not limited to linear image sensor arrays, but also point-like image sensors that scan horizontally, vertically, or two-dimensional image sensors that are electronically scanned to achieve similar purposes. can also be achieved.

<Effects> As described above, according to the present invention, bending of a pin can be detected quickly and accurately in two directions by only irradiating laser light from one direction. Moreover, the detection end may be made of, for example, a linear photo array, and the detection signal can also be obtained as a digital signal, so that the detection signal can be processed efficiently.

[Brief explanation of drawings]

FIG. 1 is a test target of an embodiment based on the present invention.
FIG. 3 is a side view of an IC element. FIG. 2 is an end view of the IC element of FIG. 1. FIG. 3 is an explanatory diagram showing an embodiment of the method based on the present invention. FIG. 4 is an explanatory diagram showing an image detected by the image sensor of FIG. 3. FIG. 5 is a diagram similar to FIG. 3, showing a modified embodiment of the embodiment of FIG. 4. 1 to 7...pin, 10...IC element, 11 to 17...
Spot, 20... Image sensor, 30... Planar light, 40... Jig.

Claims (1)

[Scope of Claims] 1. A method for detecting the bending of a plurality of pins that extend on a certain reference plane and are to be aligned parallel to each other, the method comprising: irradiating each of the plurality of pins with a light ray along a predetermined plane extending across the plane; and irradiating a light beam at an angle different from the incident angle of the light ray with a visual sensor having a light-receiving surface facing the reference plane. A light image on each pin is captured by reflected light, and pass/fail is determined based on the positional deviation of the light image captured on the visual sensor with respect to a predetermined reference position in the alignment direction and/or extension direction of the pins. A method for detecting pin bending characterized by performing the following steps.