JPH07104136B2 - Terminal tilt detection method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for detecting a tilt of a terminal of an electronic component such as a relay.

[Conventional technology]

Conventionally, as in Japanese Patent Laid-Open No. 63-293403, by imaging the terminals of chip parts (terminal bumps of flip chips) and determining the position of the center of gravity, the misalignment and tilt of the chip parts are recognized and highly accurate. There was a method of mounting a chip component, but it was not a method of detecting the inclination of the terminal itself.

A method has also been proposed in which parallel light is emitted perpendicularly to the terminals, the image is taken by a camera to detect the center of each terminal, and the tilt is detected by the distance between the centers, but only the tilt in the left and right directions of the terminal is detected. This is not possible, and there is a problem that it is not possible to cope with the case where the terminals are arranged in a grid pattern.

Japanese Patent Application Laid-Open No. 54-150089 has been proposed as a method for inspecting the bending of terminals. This proposal is a device to inspect the bending of IC terminals, more specifically DIP type plastic mold IC
The present invention relates to a device for inspecting whether or not the tip of the external terminal is within a bend in a range where it can be automatically inserted into a printed board or the like. The inspection of the bending of the terminal of the IC by this device is to hold the IC and lightly press the tip of the terminal against the semitransparent glass plate, scan the image of the tip of the terminal through the semitransparent glass plate and take the tip of each terminal. The position is extracted, and the result is compared with the reference terminal position information to make a pass / fail judgment.

However, in this conventional example, since the bending is inspected by bringing the tip of the terminal into contact with the semitransparent glass plate, it is necessary to bring the tip of the terminal into contact with the semitransparent glass plate in the inspected component having a thin terminal. Deformation of the terminals can be a problem. The contact position of the terminal with the semitransparent glass plate changes depending on the bending of the terminal. Therefore, the tip positions of the extracted terminals are not always accurate terminal positions, and cannot be applied to those that inspect bends with high accuracy. Further, there is a problem that the inspection cannot be performed with a terminal having a variation in length.

[Problems to be Solved by the Invention]

In the prior art, as described above, the inclination cannot be detected with high accuracy in all directions regardless of the size variation of the target terminal and the dimensional variation of the terminal length.
Therefore, in the present invention, the influence of the size and size of the terminal is small, and regardless of the order, even if the terminal is tilted in all directions (X, Y directions), the tilt can be detected with high accuracy. The purpose is to provide a possible method.

[Means for Solving the Problems]

The present invention has the following means to achieve the above object.

That is, for each terminal row of the component to be inspected, only the tip of the terminal is directly irradiated with light, the image is captured by the camera from above the component to be inspected, and it is captured as an image. The center is obtained, the distance between the centroids and the coordinate of the midpoint between the centroids are measured, and the inclination of the terminal is detected depending on whether the difference between the distance and the coordinate is within a reference range. The method of detecting the inclination of the terminal is as follows. Alternatively, for each row of terminals of the inspected component, only the tip of the terminal and the reference body at a fixed position are directly irradiated with light and the camera is applied from above the inspected component. Capture and capture as an image, find the centroid that is the center of each image of the terminal from this image, measure the distance from the reference body to the centroid and the distance between the centroids, the difference in the distance Whether it is within the reference range According to another aspect of the present invention, there is provided a method for detecting the inclination of a terminal, wherein the inclination of the terminal is detected.

[Action]

If the terminals of electronic parts such as relays are tilted, the distance between the terminals changes at the tips of the terminals. In order to detect the tip of the terminal, light is directly applied only to the tip of the terminal for each terminal row of the component to be inspected, and the image is captured from above the component to be inspected by the camera and captured as an image. The inclination of the terminal can be detected by obtaining the centroid, which is the center of each image of the terminal, and measuring the distance between the centroids and the coordinates of the midpoint between the centroids. However, if all the terminals are tilted in the same way, the tilt cannot be detected only by measuring the distance between the terminals. In such a case, a reference point is provided on the reference body and the positional relationship between this point and the centroid of the terminal is examined, so that the terminal inclination can be detected with high accuracy in any case. It is a thing.

〔Example〕

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

FIG. 1 is a configuration diagram showing an outline of the configuration of a terminal inclination detection method of the present invention. The inspected component 11 of this embodiment is a component in which the terminals 12 are arranged in two rows. As shown in FIG. 1, the light source 14
The terminal 12 on the side closer to is not irradiated with light, and the light source 14 is provided for each terminal row so that the light is directly irradiated only on the tip of the terminal 12 on the side farther from the light source 14. Shield plate between
Install 13. Irradiate light and CC from above the inspected part 11.
The centroid, which is the center of the image of each terminal 12 obtained by the image processing device 16 by the D camera 15 is obtained, and the distance between the centroids is measured.

FIG. 2 is a diagram showing the captured image in an easily understandable manner. The inspected component 11 in this embodiment is a terminal
12 are arranged in two rows, and five terminals 12 are arranged in each row. Further, FIG. 3 shows a flow chart of the quality judgment in the case of detecting the inclination of the terminals of the inspected component 11 in which the terminals 12 are arranged in two rows.

In FIG. 3, first, as shown in the flow chart,
The centroid T _i of each terminal is obtained from the captured image (process 31),
Then, the X-direction pitch P _j and the Y-direction pitch W _k are obtained (process 32). FIG. 2 shows an X-direction (horizontal direction) pitch P _j (j = 1, 2 ... 8) and a Y-direction (longitudinal direction) pitch W _k (k = 1, 2 ... 5) of the terminals 12. Terminal i (i = 1,2 …… 1
When the coordinates of the centroid T _i of (0) are (x _i , y _i ), P _j , W _k are expressed as follows.

P _j = x _{j + 1} −x _j (1 ≦ j ≦ 4) P _j = x _{j + 2} −x _{j + 1} (5 ≦ j ≦ 8) W _k = y _{k + 5} −y _k (1 ≦ k ≦ 5) It is determined whether or not P _j , W _k obtained as described above is within the predetermined reference range (process 33), and if not within the reference range, it is determined as defective (process 39).

However, in this determination, as shown in FIG. 4, if all the terminals 12a in one row are inclined at equal intervals in the x direction, it is also determined as a good product. In order to avoid this, the midpoint A _m (m = _m) between the centroids T _i of the terminals 12a, 12 in the x direction
1, 2 ... 8) coordinates are obtained (process 34), and the difference between the facing midpoint coordinates in the x direction (A1−A5 in FIG. 4) is calculated,
It is determined whether the difference is within the reference range (process 3
5) If it is not within the reference range, it is determined to be defective (Process 3
9).

Furthermore, if the terminals 12 facing each other are all aligned and tilted in the y direction, it will be determined as a non-defective product.
As shown in the figure, the midpoint between centroids T _{m of} terminals 12 arranged in the y direction.
The B _k coordinate is obtained (process 36), the maximum value Bmax and the minimum value Bmin in the y direction are cut from the 5 midpoint coordinates, and the remaining 3 average values Bave are obtained (process 37). The difference between the average value thus obtained and the maximum and minimum values (the example in Fig. 5 is Bmax-Bav
e) is within the reference range (process 38),
If it is not within the reference range, it is determined to be defective (process 39). Those that were within the reference range are judged as non-defective for the first time (Process 4
0).

FIG. 6 shows a part to be inspected in which a plurality of terminals 62 are arranged in one row.
It is a block diagram which showed the outline of the structure of the inspection method at the time of inspecting the inclination of the terminal of 61. FIG. 7 shows an explanatory diagram in which the images of the inspected component 61 and the plate-shaped reference body 63 are imaged from above in an easily understandable manner. Tip of terminal 62 and reference body
The light source 64 directly irradiates only 63. The centroid K _i of each terminal 62 in the x direction from the reference position 71 of the reference body 63 (i = 1, 2 ...
The distance to 5) (X4 is illustrated in FIG. 7) is calculated, and if it is not within the reference range, it is determined to be defective. On the other hand, similarly in the y direction, y from the reference position 71 of the reference body 63 to the centroid of each terminal
The determination is performed based on the distance in the direction (Y _i , i = 1, 2 ... 5 is illustrated).

Similarly, FIGS. 8 and 9 show different embodiments of the terminal inclination detection method. X direction of the inspected part 11,
In order to create each reference point in the y direction on the captured image, an optical fiber light source (not shown) is illuminated from one corner diagonally below the inspected component 11 to illuminate the component edge 91. is there. In this case, the reference body having the reference point is the inspected component 11 itself. The corner of the inspected part 11 captured by the imaging is set as the virtual origin G, and the centroid T of the terminals 12 and 12b in the row above the virtual origin G is set.
Distance DY _i (i = 1,2 ... 5) to _i (i = 1,2 ... 5)
5) and the centroid (T1 and T6 in the illustrated example) of the terminal 12b closest to the virtual origin G in the upper and lower rows in the x direction (DX _n (n
= 1, 2) is measured and it is inspected whether it is within a predetermined range. After that, the inspection is performed in accordance with the procedure of the embodiment shown in FIGS. 2, 4, and 5, so that even if all the terminals are inclined by the same amount in the same direction, The tilt can be detected.

〔The invention's effect〕

As described above, according to the present invention, for each terminal row of the inspected component, only the tip of the terminal is directly irradiated with light, the image is captured by the camera from above the inspected component, and is captured as an image. Obtain the centroid that is the center of each image, measure the distance between the centroids and the coordinates of the midpoint between the centroids, and determine the inclination of the terminal by checking whether the difference in the distance and the coordinate is within the reference range. According to the method for detecting the inclination of the terminal, which is characterized by detecting, the light is directly radiated only to the tip of the terminal and the reference body at a fixed position for each terminal row of the object to be inspected. The image is taken by a camera from above, and captured as an image, the centroid that is the center of each image of the terminal is obtained from this image, and the distance from the reference body to the centroid and the distance between the centroids are measured, The distance difference is within the reference range According to the terminal inclination detection method characterized by detecting the inclination of the terminal depending on whether or not there is little influence of terminal diameter size and dimensional variation, and regardless of that It is intended to provide a method capable of detecting the inclination with high accuracy even if the terminals are inclined in the (X, Y directions).

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of the configuration of an embodiment of a terminal inclination detection method of the present invention, and FIG. 2 is a CCD in that embodiment.
Fig. 3 is an explanatory diagram showing the image captured by the camera.
FIG. 4 is a flow chart of the quality judgment of the terminal inclination detection method of the present invention in the case of parts to be inspected arranged in rows, FIG. 4 is an explanatory diagram illustrating an imaged image showing an embodiment in the case of different terminal inclinations, FIG. 5 is an explanatory diagram illustrating an imaged image showing an embodiment in which the terminals are tilted differently, FIG. 6 is a configuration diagram showing an outline of the embodiment in the case where the terminals are in a line, and FIG. FIG. 8 is an explanatory diagram showing a captured image, FIG. 8 is an explanatory diagram showing a captured image showing a different embodiment, and FIG. 9 is a diagram showing the captured image. 11, 61 …… Inspected part, 12, 12a, 12b, 62 …… Terminal, 1
4, 64 …… Light source, 15, 65 …… CCD camera, 16, 66 …… Image processing device, T _i …… Centroid, G …… Virtual origin, Am …… Between centroids of adjacent terminals in the X direction X direction middle point, Bk …… Y direction middle point between centroids of adjacent terminals in Y direction

Claims (2)

[Claims] 1. A light for direct irradiating only the tips of the terminals for each terminal row of the component to be inspected, imaged by a camera from above the component to be inspected, captured as an image, and from this image, the center of each image of the terminal Is obtained, the distance between the centroids and the coordinates of the midpoint between the centroids are measured, and the inclination of the terminal is detected depending on whether the difference between the distance and the coordinate is within a reference range. A method for detecting the inclination of a terminal, characterized by 2. For each terminal row of the component to be inspected, only the tip of the terminal and the reference body at a fixed position are directly irradiated with light, and the image is captured by the camera from above the component to be inspected, and captured as an image. The centroid, which is the center of each image of the terminal, is obtained, the distance from the reference body to the centroid and the distance between the centroids are measured, and it is determined whether the difference in the distance is within the reference range. A method for detecting the inclination of a terminal, which comprises detecting the inclination of the terminal.