JP3131977B2 - Parts inspection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial applications]

The present invention relates to a recognition method of a visual recognition device for correcting the position / posture of an electronic component which is a work target in an electronic component mounting facility, inspecting a defective component, and the like. It relates to a method of checking whether or not there is.

[0002]

[Prior art]

In recent years, with the progress of high-mix low-volume production and high-density packaging in the circuit formation field, the size of electronic components, which are the objects to be mounted on electronic component mounting equipment, has also been reduced. It is becoming difficult for the operator to easily judge. It is still common for an operator to supply electronic components to the electronic component mounting equipment, and the operator supplies the incorrect electronic component, mounts the incorrect electronic component on the board as it is, and after mounting. It is not unusual for an example to turn out to be the wrong part.

[0003]

[Problems to be solved by the invention]

In addition to detecting a supply error of a miniaturized electronic component, it is becoming difficult to transfer a miniaturized electronic component from a component supply unit. Although the method of transferring electronic components from the component supply unit using a suction nozzle has been generalized, for small-sized electronic components, the components are sucked in a standing state (FIGS. 6A and 6B). , And oblique suction in a state where it is not completely standing but is oblique (Fig. 6
C, D) may occur. In the visual recognition unit, a method of capturing a component image with transmitted light and measuring the position and orientation has been generalized. In the case of this method,
When the component is fine, both the suction nozzle and the component are imaged, and there is a case where standing suction and oblique suction cannot be detected by the conventional pattern matching using the area, the boundary point, and the like.

[0004]

[Means for Solving the Problems]

In order to solve the above-described problem, a component inspection method according to a first invention of the present application is a component inspection method in which a normal target component is imaged and taught, and then the inspection target component is imaged and inspected by comparing with a result of the teaching. In an image obtained by imaging a normal target component, a teaching step of moving a search straight line parallel to each side to search each side and obtaining a distance from the image center position to each side, In the captured image, a search straight line along each side is set at a position corresponding to the distance from the image center position obtained in the teaching step to each side, as viewed from the obtained image center position, and the length of the image is set. And measure
An inspection step of inspecting the target component by comparing the measured length with a predetermined length of each side.

In order to solve the above-mentioned problem, the component inspection method according to the second invention of the present application provides a method in which, in the teaching step, when a search straight line is moved and each side is searched, a length corresponding to each side dimension is set as: It is characterized in that the length of each side dimension ± dimension tolerance is searched.

In order to solve the above-mentioned problem, a component inspection method according to a third aspect of the present invention provides a component inspection method which sets a search straight line along each side and measures the image length in an inspection process. As a position corresponding to the distance from the position to each side, a search straight line is set at a position that is a distance obtained by multiplying the distance from the image center position obtained in the teaching process to each side by a constant smaller than 1 and the length of the image. Is measured.

[0007]

[Action]

According to the first aspect of the present invention, with the above-described configuration, the length of the image of the inspection target component is measured at the position where each side of the component obtained when teaching the normal target component is present. Since the length of each side directly connected to the shape can be checked and inspected, a component having a different type or a component having an abnormal suction such as a component standing can be accurately determined to be abnormal. Further, since the image processing for the inspection target component is a simple process of only detecting the length of the image on the search straight line at the designated position, the inspection time of the inspection target component can be greatly reduced.

Further, according to the second aspect of the present invention, with the above-described configuration, instead of searching for each side that exactly matches the dimension of each side of the part given in advance in the catalog or specification of the part, the above-described specification is used. Since each side can be searched in consideration of the range of the allowable dimensional tolerance given by, for example, even when the lengths are different within the range of the dimensional tolerance, the search can be accurately performed. Actually, there is always variation within the dimensional tolerance, so even if there is variation within the dimensional tolerance, the relevant side can be accurately identified.
More practical.

According to the third aspect of the present invention, with the above-described configuration, even if each side exists at a position closer to the component center position than the position taught by the inspection target component because of a dimensional tolerance or the like, The length of each side can be accurately measured.

[0010]

【Example】

One embodiment of the component inspection method of the present invention will be described with reference to the drawings.

1) In an image obtained by imaging a normal electronic component, search lines 1, 2, 3, and 4 along the inclination are designated on the image based on the image center position and the inclination as shown in FIG. While sequentially translating these from the outside of the image in the direction of the center of the image, a length corresponding to the dimension of each side of the electronic component given in advance, searching for the length of the image of the electronic component that falls on the search straight line, The distance between the search straight line position and the image center position where the length of the image of the electronic component corresponding to the dimension of each side of the electronic component could be searched for the first time
5, 6, 7, and 8 are obtained in advance. 2) If the target electronic component is a rectangular point target (see FIG. 3), each half of the given vertical and horizontal dimensions of the electronic component is set to the length on the image. And the distance between the search straight line position and the image center position 9,10,11,12
3) In an image obtained by imaging the electronic component to be inspected (see FIG. 4), the image center position and inclination are obtained, and the above-mentioned 1) or 2) is obtained from the image center position. The search straight lines 13, 14, 15, 16 along the inclination of the image are designated as the distances, and the length of the image is measured on these straight lines. The obtained four lengths 17, 18, 19, and 20 are compared with the predetermined dimensions of the four sides of the electronic component, and if the four sides also match, it is determined that the electronic component is a normal component.

FIG. 1 is a flowchart of a component inspection method of the component inspection method of the present invention, and FIG. 5 is a diagram showing an example of an image of a component inspection of an electronic component in the present embodiment.

First, as shown in FIG. 5A, the image center position and the inclination are obtained in a normal electronic component image, and 4
The lengths 21, 22, 23, and 24 of the lengths corresponding to the side dimensions ± the dimension tolerance are searched, and the distances 25, 26, 27, and 28 between the position of the search straight line and the image center position at that time are obtained.

In the electronic component image to be inspected (FIGS. 5B and 5C), the image center position and the inclination are obtained. 29 = 25 × a, 30 = 26 × a, 31 = 27 × a, 32 = 28 from the image center position along the obtained inclination
A search straight line is designated at a position xa away, and the image length on the search straight line is measured. The reason for multiplying the previously determined distance from the image center position to the search straight line by a constant a (<1) is to cope with the fact that the size of an actual electronic component varies by the dimensional tolerance. is there.

The length obtained by the search straight line is the length corresponding to the four side dimensions of the electronic component given in advance and the positional relationship (left, right,
(Upper and lower) is considered, and as a result, if any of the four sides has a difference exceeding the dimensional tolerance, it is determined to be an unqualified part. In the example of FIGS. 5B and C, B is a pass,
C was judged to be unacceptable because the length of 38 exceeded the dimensional tolerance.

As described above, in one embodiment of the present invention, the same type of component and different type of component can be correctly determined.

[0017]

【The invention's effect】

According to the present invention, in order to measure the length of the image of the inspection target component at the position where each side of the component obtained when teaching the normal target component is present, each side directly connected to the shape of the inspection target component Since the length of the component can be checked and inspected, components having different types of components and components having a suction abnormality such as component standing can be accurately determined to be abnormal. Further, since the image processing for the inspection target component is a simple process of only detecting the length of the image on the search straight line at the designated position, the inspection time of the inspection target component can be greatly reduced.

Further, when searching for each side of a normal target part, instead of searching for each side that exactly matches the dimensions of each side of the part given in advance in a catalog or specification of the part, the above-mentioned specification or the like is used. Since each side can be searched in consideration of the range of the allowable dimensional tolerance given by the above, accurate search can be performed even when the lengths are different within the range of the dimensional tolerance. Actually, since there is always a variation within the dimensional tolerance, even if there is a variation within the dimensional tolerance, the corresponding side can be accurately identified, which is more practical.

In the inspection step, when a search straight line is set along each side to measure the length of the image, the image obtained in the teaching step is determined as a position corresponding to the distance from the image center position to each side. Since the length of the image is measured by setting a search straight line at a position that is a distance obtained by multiplying the distance from the center position to each side by a constant smaller than 1, the position of the part to be inspected from the position taught due to dimensional tolerances or the like Even if each side exists at a position near the component center position, the length of each side can be accurately measured.

[Brief description of the drawings]

FIG. 1 is a flowchart of a component inspection method according to the present invention.

FIG. 2 is an explanatory view showing an operation process of the component inspection method of the present invention.

FIG. 3 is an explanatory diagram showing an operation process of the component inspection method of the present invention.

FIG. 4 is an explanatory diagram showing an operation process of the component inspection method of the present invention.

FIG. 5 is a diagram showing an example of an image of an electronic component inspection according to an embodiment of the present invention.

FIG. 6 is an explanatory view showing an abnormal suction state occurring in the electronic component mounting equipment.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-100181 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G06T 1/00 G06T 7/00-7 / 60 G01B 11/24-11/255 G01N 21/88-21/958

Claims (4)

(57) [Claims] A component inspection method for imaging and teaching a normal target component, and then inspecting the inspection target component by comparing the image with the result of the teaching. A search process is performed by moving a search straight line parallel to each side to search each side and obtain a distance from the image center position to each side. Set a search straight line along each side at a position corresponding to the distance from the image center position obtained in the teaching step to each side, measure the length of the image,
An inspection step of inspecting a target component by comparing the measured length with a predetermined length of each side. In a teaching step, a center position and an inclination of an image are obtained, a search straight line is designated along the obtained inclination, and the search straight line is sequentially moved from the outside to the inside of the image to obtain a predetermined target component. A first step of retrieving a length of the target part corresponding to each side dimension on the image of the target part that falls on the search line, and a length of the image of the target part corresponding to each side dimension in the first step And a second step of obtaining a distance between the position of the search straight line and the center position of the image in which the image is detected for the first time. In the inspection step, the second step A search straight line is set along the obtained slope at a position corresponding to the distance between the position of the search straight line on each side and the image center position obtained in step, and the length of the image is measured on the search straight line. Length and each side dimension of the target part given in advance Each cognate target component by comparison, parts inspection method according to claim 1, wherein determining different and. 3. In the teaching step, when a search straight line is moved and each side is searched, a length of each side dimension ± dimension tolerance is searched as a length corresponding to each side dimension. Part inspection method described. 4. In the inspection step, when a search straight line is set along each side and the length of the image is measured, an image obtained in the teaching step is determined as a position corresponding to the distance from the image center position to each side. The component according to any one of claims 1 to 3, wherein a search straight line is set at a position having a distance obtained by multiplying a distance from the center position to each side by a constant smaller than 1 to measure the length of the image. Inspection methods.