JPH0414184A - Parts inspection method - Google Patents

Abstract

PURPOSE:To efficiently detect the difference of the dimension of parts caused by the supplyment of foreign parts or stand-absorption by measuring the dimensions of the four sides of an inspection subject and comparing them with the dimensions of the four sides instructed in advance. CONSTITUTION:In a normal parts picture, a picture center position and an inclination are calculated, lengths 21-24 of the lengths corresponding to the dimensions of the four sides + or - tolerance are retrieved by a scanning straight line, and distances 25-28 between the scanning straight line and the picture center position at that time are calculated. The picture center position and the inclination are calculated concerning a sample. Along the inclination, the scanning straight lines are designated to be 29=25a, 30=26a, 31=27a, and 32=28a (a<1) away from the picture center position. Thus, the calculated lengths are compared by taking acount of the lengths corresponding to the dimensions of the four sides of parts and the relation of position, and decided as noncompliant when even one of the four sides exceeds the dimensional tolerance. In the specimen, the figure (B) is good, but the figure (C) is not good because a length 38 exceeds the dimensional tolerance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a recognition method using a visual recognition device for purposes such as correcting the position and orientation of electronic components that are work objects in electronic component mounting equipment and inspecting defective components. The present invention relates to a method of inspecting whether an electronic component to be mounted is a specified component.

Conventional technology In recent years, as high-mix, low-volume production and high-density packaging have progressed in the field of circuit formation, electronic components, which are the workpieces of electronic component mounting equipment, have also become smaller. It is becoming increasingly difficult for operators to determine whether or not different parts are used. It is still common for the operator to supply electronic components to electronic component mounting equipment, and the operator may supply the wrong electronic component and then mount the wrong electronic component on the board. It is not uncommon for parts to later be found to be the wrong parts.

Problems to be Solved by the Invention In addition to detecting the supply of miniaturized electronic components,
It is also becoming difficult to transfer miniaturized electronic components from component supply departments. The method of transferring electronic components from the component supply section using a suction nozzle has become common;
For micro-shaped electronic components, there is vertical suction in which the component is attracted while standing up (C9D in Figure 6), and oblique suction in which the component is not completely erect but is tilted (Figure 6C9).
D) may occur. In visual recognition units, it has become common to take an image of the part using transmitted light and measure its position and orientation.In this method, when the part is minute, both the suction nozzle and the part are imaged,
In conventional pattern matching using areas, boundary points, etc., standing adsorption is used.

There were cases where oblique adsorption could not be detected.

Means for Solving the Problems Therefore, the present invention provides: 1) In an image taken of a normal electronic component, a search straight line 1 along the inclination is created on the image based on the image center position and inclination as shown in FIG. .2, 3.4, and search for the length corresponding to the four side dimensions of the electronic component while sequentially moving them in parallel from the outside of the image toward the center of the image, and find the search straight line position where the length can be searched for the first time. The distances 5, 6, and 7.8 between Convert half of each to the length on the image and calculate in advance the distances between the search straight line position and the image center position as 9, 10, 11.12,
3) In the image taken of the electronic component to be inspected (
(see Figure 4), find the image center position and inclination, and calculate the above 1) from the image center position.

Alternatively, search straight lines 13, 14, 15, and 16 along the inclination of the image are specified at the distance determined in 2), and the length of the image is measured on these straight lines. The four lengths obtained17
．． 18, 19. 20 and 4 of the electronic components given in advance
The side dimensions are compared, and if all four sides match, the part is determined to be normal.

With the above-described configuration, the present invention inspects electronic components by measuring dimensions on images even if they are minute, so it is possible to accurately determine whether the components are of the same type or different types, and to prevent the dimensions from appearing short. Utilizing this, it is also possible to detect standing adsorption.

Embodiment An embodiment of the component inspection method of the present invention will be described with reference to the drawings. FIG. 1 is a flowchart of the component inspection method of the present invention, and FIG. 6 is a diagram showing an example of an image of component inspection of an electronic component in this embodiment.

First, as shown in Fig. 5, the image center position and inclination are determined in advance in a normal electronic component image, and a search straight line is determined to have a length equivalent to the four side dimensions ± a length of dimensional tolerance of 21.22, 23.
24, and find the distance 25°26.27.28 between the position of the search straight line and the image center position at that time.

The image center position and inclination are determined in the image of the electronic component to be inspected (FIG. 6, C9D). 29-=25Xa from the image center position along the obtained inclination.

30=26Xa, 31=27X&, 32=28X
Specify a search straight line at a distant position and measure the image length on the search straight line. The reason why the distance from the image center position to the search straight line, which was determined in advance, is multiplied by a constant a (1) is to accommodate the fact that the size of actual electronic components varies due to dimensional tolerances. be.

The length obtained by the search straight line is compared with the length equivalent to the four side dimensions of the electronic component given in advance, taking into account the positional relationship (left and right, top and bottom), and as a result, even one of the four sides exceeds the dimensional tolerance. If detected, it is determined that the part is ineligible. Figure 5B.

In the example of C, B is passed, but C is judged to be rejected because the length of 38 exceeds the dimensional tolerance.As described above, in one embodiment of the present invention, B is the same type of part.

We were able to correctly identify dissimilar parts.

Effects of the Invention According to the present invention, it is possible to efficiently detect differences in part dimensions due to supply of different parts and standing suction by measuring the dimensions of the four sides of the image of the object to be inspected and comparing them with the dimensions of the four sides taught in advance. I can do it. In addition, the dimension measurement position in the image to be inspected is a fixed distance from the image center position, and the operation of searching for dimensions is moved to pre-processing, so the processing during inspection can be completed in a short time.

[Brief explanation of the drawing]

Figure 1 is a flowchart of the component inspection method of the present invention;
4 is an explanatory diagram showing the operation process of the component inspection method of the present invention, FIG. 5 is a diagram showing an example of an image for inspecting an electronic component in an embodiment of the present invention, and FIG. 6 is an explanatory diagram showing the operation process of the component inspection method of the present invention. FIG. 3 is an explanatory diagram showing an abnormal suction state occurring in the mounting equipment. Name of agent: Patent attorney Shigetaka Awano and one other person Figure Lt=L3. Lz=L4 9=ll=-! -! −(−♀)? to = tz = , (= 7) Figure Figure Figure (B> (B) (C) (Q)

Claims (2)

[Claims] (1) Find the image center position and inclination on the image of a normal target object, specify a search straight line along the determined inclination, move the search straight line sequentially from the outside to the inside of the image, and A first step of searching for the length on the image corresponding to the four side dimensions, and a second step of obtaining the distance between the position of the search straight line where the length corresponding to the four side dimensions was first detected in the first step and the center position of the image. A component inspection method having a teaching process consisting of: (2) The component inspection method according to claim 1, wherein when the object is a rectangular point-symmetrical object, half of the vertical and horizontal dimensions of the object given in advance is used as the distance between the position of the search straight line and the center position of the image. (3) In the image taken of the inspection object,
Find the image center position and tilt, specify a search straight line along the determined tilt from the image center position to the distance between the search straight line position and the image center, and measure the length of the image on the search straight line. A parts inspection method that determines whether an object is the same type or different type by comparing the four lengths given with the four side dimensions of the object given in advance.