JP7511824B2 - Apparatus and method for inspecting the appearance of electronic components - Google Patents

Description

This disclosure relates to an electronic component appearance inspection device and an electronic component appearance inspection method, and in particular to an electronic component appearance inspection device and electronic component appearance inspection method that can perform accurate and reliable appearance inspection of the ridges of electronic components and their vicinity.

Conventionally, a method for visually inspecting a ridgeline has been used in which an oblique image of the ridgeline from the center of an object to be inspected to an angle close to the normal line is captured by an imaging means, and the oblique image of the ridgeline is inspected.
For example, one such conventional appearance inspection method is to irradiate the ridgeline with uniform illumination from multiple angles, and detect any defects on the ridgeline by utilizing the phenomenon in which the tendency of luminance change changes.

JP 2010-266366 A

However, no method has been developed to accurately and reliably inspect the appearance of the ridges and their vicinity of electronic components.
The present disclosure has been made in consideration of these points, and aims to provide an electronic component appearance inspection apparatus and an electronic component appearance inspection method that can accurately and reliably detect the appearance of the ridges and their vicinity of the electronic components to be inspected.

The present disclosure relates to an appearance inspection device for electronic components that inspects the appearance of an electronic component having at least a top surface, a side surface, and a ridgeline between the top surface and the side surface, the device comprising: a support section that supports the electronic component; a first irradiation device that irradiates light onto the top surface of the electronic component to obtain a first reflected light including reflected light from the top surface of the electronic component, reflected light from the ridgeline, and reflected light from the side surface; a second irradiation device that irradiates light onto the ridgeline of the electronic component to obtain a second reflected light including reflected light from the ridgeline of the electronic component, reflected light from the top surface, and reflected light from the side surface; The electronic component appearance inspection device includes a third irradiation device that irradiates light onto the side of the component and obtains a third reflected light including reflected light from the side of the electronic component, reflected light from the top surface, and reflected light from the ridge line, an imaging device that receives the first reflected light, second reflected light, and third reflected light from the electronic component to obtain a first image, a second image, and a third image, and an image processing device connected to the imaging device, and the image processing device detects defects present on the top surface, the ridge line, or the side based on the first image, the second image, and the third image.

The present disclosure relates to an electronic component appearance inspection device further comprising a reflecting device that guides a first reflected light from the electronic component, a second reflected light from the electronic component, and a third reflected light from the electronic component to the imaging device.

The present disclosure relates to an electronic component appearance inspection device, in which the reflecting device guides the direct reflected light of the light from the first irradiation device, the direct reflected light of the light from the second irradiation device, and the direct reflected light of the light from the third irradiation device to the imaging device.

The present disclosure relates to an electronic component appearance inspection device, in which the image processing device creates an inspection data pattern including binarized data for the top surface, the ridgeline, and the side surface on the first image, binarized data for the top surface, the ridgeline, and the side surface on the second image, and binarized data for the top surface, the ridgeline, and the side surface on the third image, and detects defects present on the top surface, the ridgeline, or the side surface while comparing the inspection data pattern with a predetermined reference data pattern corresponding to the inspection data pattern.

The present disclosure relates to an appearance inspection device for electronic components, in which a plurality of the reflecting devices are arranged at equal intervals around the outer periphery of the electronic component, and a plurality of first images, second images, and third images are obtained based on the light from each of the first irradiation device, the second irradiation device, and the third irradiation device.

The present disclosure relates to an electronic component visual inspection device, in which the reflecting device includes a mirror or a prism.

The present disclosure relates to an appearance inspection device for electronic components, in which the first irradiation device emits light in a first wavelength range, the second irradiation device emits light in a second wavelength range different from the first wavelength range, and the third irradiation device emits light in a third wavelength range different from the first wavelength range and the second wavelength range.

The present disclosure relates to an appearance inspection device for electronic components, the imaging device having an image sensor or optical sensor that receives the first reflected light, the second reflected light, and the third reflected light to obtain a first image, a second image, and a third image.

The present disclosure relates to an electronic component appearance inspection device, in which the electronic component has an electronic component body and an electrode connected to the electronic component body via a boundary line, and the image processing device creates and combines grayscale image data on the top surface, the ridge line, and the side surface on the first image, grayscale image data on the top surface, the ridge line, and the side surface on the second image, and grayscale image data on the top surface, the ridge line, and the side surface on the third image for a pair of ridge lines that are perpendicular to the boundary line of the electronic component and face each other, and identifies locations with low correlation and differences by bringing a grayscale image obtained by combining the grayscale images of the first image, the second image, and the third image for one ridge line and a grayscale image obtained by combining the grayscale images of the first image, the second image, and the third image for the other ridge line close to each other and comparing them, thereby detecting defects present on the top surface, the ridge line, or the side surface.

The present disclosure relates to an appearance inspection method for an electronic component that inspects the appearance of an electronic component having at least a top surface, a side surface, and a ridge line between the top surface and the side surface, the method comprising the steps of: irradiating light from a first irradiation device onto the top surface of the electronic component to obtain a first reflected light including reflected light from the top surface of the electronic component, reflected light from the ridge line, and reflected light from the side surface; irradiating light from a second irradiation device onto the ridge line of the electronic component to obtain a second reflected light including reflected light from the ridge line of the electronic component, reflected light from the top surface, and reflected light from the side surface; This is an appearance inspection method for electronic components, comprising the steps of: irradiating light from a third irradiation device onto the side of the component to obtain third reflected light including reflected light from the side of the electronic component, reflected light from the top surface, and reflected light from the ridge; receiving the first reflected light, second reflected light, and third reflected light from the electronic component with an imaging device to obtain a first image, a second image, and a third image; and detecting defects present on the top surface, the ridge, and the side based on the first image, the second image, and the third image with an image processing device.

The present disclosure relates to a method for visually inspecting an electronic component, further comprising a step of directing a first reflected light from the electronic component, a second reflected light from the electronic component, and a third reflected light from the electronic component to the imaging device using a reflecting device.

The present disclosure relates to a method for visually inspecting electronic components, in which the reflecting device guides the direct reflected light of the light from the first irradiation device, the direct reflected light of the light from the second irradiation device, and the direct reflected light of the light from the third irradiation device to the imaging device.

The present disclosure relates to a method for visually inspecting an electronic component, in which the image processing device creates an inspection data pattern including binarized data for the top surface, the ridgeline, and the side surface on the first image, binarized data for the top surface, the ridgeline, and the side surface on the second image, and binarized data for the top surface, the ridgeline, and the side surface on the third image, and detects defects present on the top surface, the ridgeline, or the side surface while comparing the inspection data pattern with a predetermined reference data pattern corresponding to the inspection data pattern.

The present disclosure relates to a method for visually inspecting electronic components, in which the first irradiation device emits light in a first wavelength range, the second irradiation device emits light in a second wavelength range different from the first wavelength range, and the third irradiation device emits light in a third wavelength range different from the first wavelength range and the second wavelength range.

The present disclosure relates to a method for detecting defects present on the top surface, the top edge, or the side surface, by comparing a grayscale image obtained by combining the grayscale images of the first, second, and third images for one top edge and a grayscale image obtained by combining the grayscale images of the first, second, and third images for the other top edge, with each other, by bringing the grayscale images of the first, second, and third images for the other top edge closer to each other and comparing the grayscale images, and thereby identifying locations with low correlation and differences and detecting defects present on the top surface, the top edge, or the side surface.
A method for visually inspecting electronic components.

This disclosure makes it possible to perform visual inspection of ridges and their vicinity in electronic components with high accuracy.

FIG. 1A is a side view showing one embodiment of an appearance inspection apparatus for electronic components according to the present disclosure. FIG. 1B is a side view showing a modified example of the visual inspection apparatus for electronic components. FIG. 2 is a combined view of a first image, a second image, and a third image obtained by capturing an image of an electronic component. FIG. 3 is a diagram showing a first image obtained by capturing an image of an electronic component. FIG. 4 is a diagram showing a second image obtained by capturing an image of the electronic component. FIG. 5 is a diagram showing a third image obtained by capturing an image of an electronic component. FIG. 6 is a diagram showing a reference data pattern including a first image, a second image, and a third image. FIG. 7 is a side view showing a state in which a first image is obtained by irradiating light from a first irradiation device onto an electronic component. FIG. 8A is a side view showing a state in which a second image is obtained by irradiating light from a second irradiation device onto an electronic component. FIG. 8B is a plan view showing a state in which the second irradiation device irradiates the electronic component with light to obtain a second image. FIG. 9 is a side view showing a state in which the third irradiation device irradiates the electronic component with light to obtain a third image. FIG. 10 is a diagram showing the outer shape of an electronic component to be inspected. FIG. 11 is a flowchart showing a method for inspecting the appearance of an electronic component. FIG. 12 is a diagram showing a modified example of an appearance inspection apparatus for electronic components according to the present disclosure, and is a diagram showing an ideal boundary line between the electronic component body and the electrodes, which is a combination of the first image, the second image, and the third image. FIG. 13 is a diagram combining the first, second, and third images, showing a distorted boundary line between the electronic component body and the electrode. FIG. 14A is a combined view of the first, second, and third images of opposing ridgelines. FIG. 14B is a diagram of one edge line in which the first, second, and third images are combined. FIG. 15 is a comparison of grayscale images for a pair of opposing edges.

<One embodiment of the present disclosure>
Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.
1A to 11 are diagrams showing an embodiment of an appearance inspection apparatus and an appearance inspection method for electronic components according to the present disclosure.

First, the electronic component W to be inspected by the electronic component visual inspection device will be described with reference to FIG. 10.

As shown in FIG. 10, the electronic component W has an electronic component body W1 and a pair of electrodes W2, W2 provided on both sides of the electronic component body W1. The electronic component W has an overall rectangular parallelepiped shape with an upper surface 1, a side surface 2, and a ridge line 3 between the upper surface 1 and the side surface 2.

Examples of such electronic components W include semiconductors such as chip resistors, chip inductors, multilayer ceramic capacitors, and chip LEDs.

The electronic component appearance inspection device according to this embodiment inspects the appearance of the electronic component W, particularly the ridge 3, the top surface 1 near the ridge 3, and the side surface 2 near the ridge 3.

As shown in FIG. 1A, an appearance inspection device 10 for electronic components that inspects such electronic components W includes a table (support) 14 that supports the electronic components W, a first irradiation device 11 that irradiates light mainly onto the top surface 1 of the electronic components W on the table 14 near the ridge line 3, a second irradiation device 12 that irradiates light mainly onto the ridge line 3 of the electronic components W on the table 14, and a third irradiation device 13 that irradiates light mainly onto the side surface 2 of the electronic components W on the table 14 near the ridge line 3.

Of these, the first irradiation device 11 irradiates light onto the top surface 1 of the electronic component W near the ridge line 3, generating a first reflected light that includes reflected light from the top surface 1 of the electronic component W, reflected light from the ridge line 3, and reflected light from the side surface 2.

The second irradiation device 12 also irradiates light onto the edge 3 of the electronic component W to generate second reflected light including reflected light from the edge 3 of the electronic component W, reflected light from the top surface 1, and reflected light from the side surface 2.

Furthermore, the third irradiation device 13 irradiates light onto the side surface 2 near the ridge line 3 of the electronic component W, generating a third reflected light including reflected light from the side surface 2 of the electronic component W, reflected light from the top surface 1, and reflected light from the ridge line 3.

The first reflected light, second reflected light, and third reflected light from the electronic component W are guided by the reflecting device 15 to the imaging device 20, which receives the first reflected light, second reflected light, and third reflected light. The imaging device 20 then generates a first image based on the first reflected light, generates a second image based on the second reflected light, and obtains a third image based on the third reflected light.

An image processing device 25 is also connected to the imaging device 20, and this image processing device 25 detects a defect a2 on the edge 3 of the electronic component W, a defect a1 on the top surface 1 near the edge 3, and a defect a3 on the side surface 2 near the edge 3 based on the first image, the second image, and the third image.

In this embodiment, the first reflected light from the electronic component W, the second reflected light from the electronic component W, and the third reflected light from the electronic component W are all guided to the imaging device 20 by a reflecting device 15 such as a mirror or prism described below. In this case, the reflecting device 15 guides the direct reflected light of the light from the first irradiation device 11, the direct reflected light of the light from the second irradiation device 12, and the direct reflected light of the light from the third irradiation device 13 to the imaging device 20. Note that the reflecting device 15 is not limited to a mirror or a prism, and a wavelength cut filter that reflects visible light or a specific wavelength can also be used.

The imaging device 20 also has an imaging device body 21 and a lens 22 provided at the lower end of the imaging device body 21.

The electronic component W has a rectangular parallelepiped shape and a rectangular parallelepiped top surface 1 (see FIG. 10). In order to detect defects on the four sides of the top surface 1 of the electronic component W, i.e., the four ridges 3 and the top surface 1 and side surfaces 2 in their vicinity, it is preferable that reflecting devices 15 consisting of mirrors, prisms, etc. are provided at a total of four locations above and outside the four sides of the top surface 1, corresponding to the four sides of the top surface 1. Alternatively, reflecting devices 15 may be provided at four additional locations above and outside the four corners of the top surface 1, for a total of eight locations.

Alternatively, at least two reflecting devices 15 are provided on the outside and above a pair of opposing sides of the upper surface 1, corresponding to a pair of opposing sides of the upper surface 1.

As shown in FIG. 1A, the first irradiation device 11, the second irradiation device 12, and the third irradiation device 13 each emit illumination light in a different wavelength range, thereby efficiently separating the directly reflected light from the scattered reflected light, thereby enabling defect inspection suitable for each device to be performed.

In this embodiment, for example, the light irradiated from the first irradiation device 11 is blue light with a wavelength of 300 nm or more and 550 nm or less, the light irradiated from the second irradiation device 12 is green light with a wavelength of 470 nm or more and 620 nm or less, and the light irradiated from the third irradiation device 13 is red light with a wavelength of 580 nm or more and 1000 nm or less.

Here, the light irradiated from the first irradiation device 11 is directed toward the top surface 1, and light is directly reflected from the top surface 1. This directly reflected light from the top surface 1 is sent to the imaging device 20 via the reflecting device 15 (see FIG. 7). The light irradiated from the second irradiation device 12 is directed toward the ridge line 3, and light is directly reflected from the ridge line 3. This directly reflected light from the ridge line 3 is sent to the imaging device 20 via the reflecting device 15 (see FIG. 8A and FIG. 8B). The light irradiated from the third irradiation device 13 is directed toward the side surface 2, and light is directly reflected from the side surface 2. This directly reflected light from the side surface 2 is sent to the imaging device 20 via the reflecting device 15 (see FIG. 9).

In addition, the imaging device body 21 of the imaging device 20 has a full-color imaging means that can distinguish between three or more colors.

The imaging device body 21 of the imaging device 20 is, for example, a CCD (Charge Coupled Device) camera or a CMOS (Complementary Metal-Oxide Semiconductor) camera having one imaging plate that generates the first image, the second image, and the third image, or multiple imaging plates corresponding to each image.

The table 14 that supports the electronic components W is made of a transparent support. Here, the "transparent" nature of the transparent support that constitutes the table 14 means that the visible light transmittance, specified as the average value of the transmittance at each wavelength when measured using a spectrophotometer (Shimadzu Corporation's "UV-3100PC" JIS K 0115 compliant product) within the measurement wavelength range of 380 nm to 780 nm, is 50% or more, preferably 80% or more.

The transparent support constituting the table 14 is made of, for example, glass, and may have any shape and be rotatable around any vertical rotation axis. When the table 14 is rotatable, the electronic component W to be inspected is placed at a position offset from the center of the table 14 made of the transparent support, in other words, at a position offset from the rotation axis of the table 14.

As described above, the electronic component W to be inspected may have a defect a1 on its top surface 1, a defect a2 on its edge 3, and a defect a3 on its side surface 2.

The defects a1, a2, and a3 formed in the electronic component W include, for example, cracks, chips, stains, scratches, cracks, disconnection of the electrode W2, adhesion of foreign matter, burrs, etc.

For example, if the wiring on the edge 3 of the electrode W2 is broken, no electricity will flow even if electricity is applied to the board on which the electronic component W is mounted, and the electrical product including the board on which the electronic component W is mounted will not function. Alternatively, if electricity is released while a foreign object is still attached, the foreign object may cause an electrical short circuit and start a fire.

According to this embodiment, defects a1, a2, and a3 that exist on edge line 3 of electronic component W and in its vicinity can be reliably detected, thereby improving the yield of electronic components.

Next, the first irradiation device 11, the second irradiation device 12, and the third irradiation device 13 will be further described with reference to FIG. 1A.

As shown in FIG. 1A, the first irradiation device 11 is provided between the imaging device 20 and the electronic component W, and is positioned closer to the imaging device 20 than the reflecting device 15, such as a mirror.

For example, the first irradiation device 11 irradiates parallel light or nearly parallel light (or irradiation light having a planar half angle of 10° or less) having a wavelength in a specific range (for example, 300 nm or more and 550 nm or less), and the first irradiation device 11 is, for example, an LED light.

As shown in FIG. 1A, the second irradiation device 12 is provided between the imaging device 20 and the electronic component W, and is provided above and adjacent to a reflecting device 15 such as a mirror.

The second irradiation device 12 irradiates parallel or nearly parallel light (or irradiation light having a planar half angle of 10° or less) having a wavelength in a specific range (for example, 470 nm or more and 620 nm or less), and the second irradiation device 12 is, for example, an LED light.

As shown in FIG. 1A, the third irradiation device 13 is disposed at a position approximately the same as or behind the electronic component W as seen from the imaging device 20, and in this embodiment, the third irradiation device 13 is disposed below the table 14.

The third irradiation device 13 irradiates parallel or nearly parallel light (or irradiation light having a planar half angle of 10° or less) with a wavelength in a specific range (for example, 580 nm or more and 1000 nm or less), and the third irradiation device 13 is, for example, an LED light.

The first irradiation device 11, the second irradiation device 12, and the third irradiation device 13 shown in FIG. 1A all have a structure that surrounds the electronic component W from the outside when viewed from above in a plane. In this embodiment, it is preferable that the first irradiation device 11, the second irradiation device 12, and the third irradiation device 13 all have a ring shape in a plane that surrounds the electronic component W from the outside.

In the embodiment shown in FIG. 1A, the electronic component W is placed on the table 14, and the table 14 supports the electronic component. However, the present invention is not limited to this. As shown in FIG. 1B, the electronic component W may be held by a conveying device 18 having a suction nozzle 18a and conveyed to a predetermined position below the reflecting device 15.

In FIG. 1B, a conveying device 18 having a suction nozzle 18a constitutes a support section that supports the electronic component W.

Next, the operation of this embodiment configured as described above, i.e., the method for visually inspecting electronic components, will be explained using the flowchart shown in FIG. 11.

First, place the electronic component W shown in FIG. 10 on the table 14.

7, the first irradiation device 11 directly irradiates the top surface 1 near the ridge 3 of the electronic component W, and the first reflected light from the top surface 1, ridge 3, and side surface 2 is sent to the imaging device 20 via the reflector 15. Next, as shown in FIGS. 8A and 8B, the second irradiation device 12 directly irradiates the ridge 3 of the electronic component W, and the second reflected light from the top surface 1, ridge 3, and side surface 2 is sent to the imaging device 20 via the reflector 15. Next, as shown in FIG. 9, the third irradiation device 13 directly irradiates the side surface 2 near the ridge 3 of the electronic component W, and the second reflected light from the top surface 1, ridge 3, and side surface 2 is sent to the imaging device 20 via the reflector 15.

The irradiation of the top surface 1 with direct light from the first irradiation device 11, the irradiation of the ridge line 3 with direct light from the second irradiation device 12, and the irradiation of the side surface with direct light from the third irradiation device 13 may be performed sequentially in this order, or may be performed simultaneously.

First, the action of direct light irradiation from the first irradiation device 11 onto the electronic component W will be described. The first irradiation device 11 has a ring shape that surrounds the electronic component W from the outside, and therefore the first irradiation device 11 can directly irradiate the top surface 1 of the electronic component W, particularly the top surface 1 in the vicinity of the ridge line 3, with light from the entire outer periphery of the electronic component W (see FIG. 7).

Figure 7 shows the state in which light is directly irradiated from the first irradiation device 11 mainly onto the top surface 1 of the electronic component W.

In FIG. 7, when direct light is irradiated from the first irradiation device 11 mainly onto the top surface 1 of the electronic component W, direct reflection occurs on defect-free parts of the top surface 1, and the directly reflected light from the top surface 1 is guided to the imaging device 20 via the reflecting device 15. In this case, if a defect a1 is present on the top surface 1, the direct light from the first irradiation device 11 causes scattered reflection at the defect a1. The scattered reflected light generated at the defect a1 becomes light that scatters in all directions from the defect a1.

The direct reflected light generated by the direct light being reflected from a defect-free portion of the top surface 1 of the electronic component W is a strong light that is guided to the imaging device 20, but on the other hand, the scattered reflected light generated by the reflection from the defect a1 on the top surface 1 is hardly guided to the imaging device 20.

Similarly, when direct light is irradiated from the first irradiation device 11 mainly onto the top surface 1 of the electronic component W, direct reflected light occurs at the portion of the ridge line 3 that is free of defects, but the direct reflected light from the ridge line 3 is not guided to the imaging device 20 via the reflecting device 15. In this case, if a defect a2 exists on the ridge line 3, the direct light from the first irradiation device 11 causes scattered reflection at the defect a2. The scattered reflected light generated at the defect a2 is scattered in all directions from the defect a2, but some of it is guided to the imaging device 20 via the reflecting device 15.

The direct reflected light generated by the direct light being reflected by a defect-free portion of the edge line 3 of the electronic component W is not guided from the reflecting device 15 to the imaging device 20, but the scattered reflected light generated by the direct light being reflected by the defect a2 of the edge line 3 is partially guided from the reflecting device 15 to the imaging device 20.

Similarly, when direct light is irradiated from the first irradiation device 11 mainly onto the top surface 1 of the electronic component W, direct reflected light occurs at parts of the side surface 2 that are free of defects, but the direct reflected light from the side surface 2 is not guided to the imaging device 20 via the reflecting device 15. In this case, if a defect a3 exists on the side surface 2, the direct light from the first irradiation device 11 causes scattered reflection at the defect a3. The scattered reflected light generated at the defect a3 is scattered in all directions from the defect a3, and some of it is guided to the imaging device 20 via the reflecting device 15.

In this way, the direct reflected light generated by reflection from a defect-free portion of the side surface 2 of the electronic component W is not guided from the reflecting device 15 to the imaging device 20, but on the other hand, a portion of the scattered reflected light generated by reflection from the defect a3 of the side surface 2 is guided from the reflecting device 15 to the imaging device 20.

As described above, by irradiating the top surface 1 of the electronic component W mainly with direct light from the first irradiation device 11, direct reflection occurs mainly in defect-free areas on the top surface 1 of the electronic component W, and diffuse reflection occurs mainly in defective areas on the ridges 3 and side surfaces 2. The direct reflected light and diffuse reflected light generated by direct reflection and diffuse reflection become the first reflected light and are sent to the imaging device 20 via the reflecting device 15 (see Figure 6).

Next, the imaging device body 21 of the imaging device 20 receives the first reflected light generated by reflection from the top surface 1, the ridge 3, and the side surface 2 of the electronic component W, and obtains a first image (see FIG. 3).

The first image from the imaging device 20 is then sent to the image processing device 25. As described above, by irradiating the upper surface 1 with direct light from the first irradiation device 11, the direct reflected light from the defect-free portion of the upper surface 1 is sent to the imaging device 20 via the reflecting device 15, and almost no scattered reflected light generated by the defect a1 on the upper surface 1 is sent from the reflecting device 15 to the imaging device 20.

As a result, in the first image, the defect-free parts of the top surface 1 appear bright, but the defect a1 on the top surface 1 appears clearly black.

In this way, the image processing device 25 can clearly detect the defect a1 on the upper surface 1 in the first image.

On the other hand, the light directly reflected from the non-defective portion of the ridgeline 3 in the first image is not guided from the reflecting device 15 to the imaging device 20, and so appears dark. The light scattered and reflected from the defect a2 on the ridgeline 3 is partially guided from the reflecting device 15 to the imaging device 20, so the defect a2 on the ridgeline 3 appears slightly brighter.

In this way, the image processing device 25 can detect the defect a2 on the edge line 3 in the first image with a certain degree of accuracy.

Similarly, in the first image, the direct reflected light from the defect-free portion of side surface 2 is not guided from reflecting device 15 to imaging device 20, and so appears dark. The scattered reflected light generated by defect a3 on side surface 2 is partially guided from reflecting device 15 to imaging device 20, and so defect a3 on side surface 2 appears slightly brighter.

In the image processing device 25, the defect a3 on the side surface 2 can be detected with a certain degree of accuracy in the first image.

In this embodiment, direct reflected light refers to reflected light that contains a large amount of light components that are reflected directly (specularly) when light is irradiated, and scattered reflected light refers to reflected light that is caused by scattered reflection (also called diffuse reflection) when light is irradiated.

Next, the effect of direct irradiation of light from the second irradiation device 12 onto the electronic component W will be described. The second irradiation device 12 has a ring shape that surrounds the electronic component W, and therefore the second irradiation device 12 can directly irradiate light onto the edge line 3 of the electronic component W from the outside of the entire circumference of the electronic component W (see Figures 8A and 8B).

Figure 8A is a side view of the state in which direct light is irradiated from the second irradiation device 12 mainly onto the edge line 3 of the electronic component W, and Figure 8B is a plan view of the same. As shown in Figure 8B, the direct light from the second irradiation device 12 passes beside the reflecting device 15 and can reach the electronic component W without interfering with the reflecting device 15.

In FIG. 8A, when direct light is irradiated from the second irradiation device 12 mainly onto the ridgeline 3 of the electronic component W, direct reflection occurs at the defect-free portion of the ridgeline 3, and the directly reflected light from the ridgeline 3 is guided to the imaging device 20 via the reflecting device 15. In this case, if a defect a2 exists on the ridgeline 3, the direct light from the second irradiation device 12 causes scattered reflection at the defect a2. The scattered reflected light generated at the defect a2 becomes light that scatters in all directions from the defect a2.

The direct reflected light generated by the direct light being reflected by a defect-free portion of the edge line 3 of the electronic component W is a strong light that is guided to the imaging device 20, but on the other hand, the scattered reflected light generated by the reflection by the defect a2 of the edge line 3 is hardly guided to the imaging device 20.

Similarly, when light is irradiated directly from the second irradiation device 12 mainly onto the ridges 3 of the electronic component W, light is directly reflected from the parts of the top surface 1 that are free of defects, but the light directly reflected from the top surface 1 is not guided to the imaging device 20 via the reflecting device 15. In this case, if a defect a1 is present on the top surface 1, the light from the second irradiation device 12 causes scattered reflection at the defect a1. The scattered reflected light generated by the defect a1 is scattered in all directions from the defect a1, but some of it is guided to the imaging device 20 via the reflecting device 15.

The direct reflected light generated by the direct light being reflected by a defect-free portion of the top surface 1 of the electronic component W is not guided from the reflecting device 15 to the imaging device 20, but the scattered reflected light generated by the direct light being reflected by the defect a1 on the top surface 1 is partially guided from the reflecting device 15 to the imaging device 20.

Similarly, when light is irradiated directly from the second irradiation device 12 mainly onto the ridgeline 3 of the electronic component W, direct reflection light occurs at the defect-free portion of the side surface 2, but the direct reflection light from the side surface 2 is not guided to the imaging device 20 via the reflection device 15. In this case, if a defect a3 exists on the side surface 2, the direct light from the second irradiation device 12 causes scattered reflection at the defect a3. The scattered reflection light generated at the defect a3 is scattered in all directions from the defect a3, but some of it is guided to the imaging device 20 via the reflection device 15.

In this way, the direct reflected light generated by reflection from a defect-free portion of the side surface 2 of the electronic component W is not guided from the reflecting device 15 to the imaging device 20, but on the other hand, a portion of the scattered reflected light generated by reflection from the defect a3 of the side surface 2 is guided from the reflecting device 15 to the imaging device 20.

As described above, by irradiating light directly from the second irradiation device 12 mainly onto the ridgeline 3 of the electronic component W, direct reflection mainly occurs in defect-free areas of the ridgeline 3 of the electronic component W, and diffuse reflection mainly occurs in defective areas of the top surface 1 and side surface 2. The direct reflected light and diffuse reflected light generated by the direct reflection and diffuse reflection become second reflected light and are sent to the imaging device 20 via the reflection device 15 (see Figure 6).

Next, the imaging device body 21 of the imaging device 20 receives the second reflected light generated by reflection from the top surface 1, the ridge 3, and the side surface 2 of the electronic component W, and obtains a second image (see FIG. 4).

The second image from the imaging device 20 is then sent to the image processing device 25. As described above, when the direct light from the second irradiation device 12 is irradiated onto the ridgeline 3, the direct reflected light from the defect-free portion of the ridgeline 3 is sent to the imaging device 20 via the reflecting device 15, and almost no scattered reflected light generated by the defect a2 on the ridgeline 3 is sent from the reflecting device 15 to the imaging device 20.

As a result, in the second image, the non-defective parts of edge line 3 appear bright, but defect a2 on edge line 3 appears clearly black.

In this way, the image processing device 25 can clearly detect the defect a2 on the edge line 3 in the second image.

On the other hand, in the second image, the reflected light from the defect-free parts of the upper surface 1 is not guided from the reflecting device 15 to the imaging device 20, and so appears dark. Since a portion of the scattered reflected light generated by the defect a1 on the upper surface 1 is guided from the reflecting device 15 to the imaging device 20, the defect a1 on the upper surface 1 appears slightly brighter.

In this way, the image processing device 25 can detect the defect a1 on the upper surface 1 in the second image with a certain degree of accuracy.

Similarly, in the second image, reflected light from a non-defective portion of side surface 2 is not guided from reflecting device 15 to imaging device 20, and so appears dark. A portion of the scattered reflected light generated by defect a3 on side surface 2 is guided from reflecting device 15 to imaging device 20, so defect a3 on side surface 2 appears slightly brighter.

In this way, the image processing device 25 can detect the defect a3 on the side surface 2 in the second image with a certain degree of certainty.

Next, the effect of direct irradiation of light from the third irradiation device 13 onto the electronic component W will be described. The third irradiation device 13 has a ring shape, and therefore the third irradiation device 13 can directly irradiate light onto the side surface 2 of the electronic component W, particularly the side surface 2 in the vicinity of the ridge line 3, from the outside of the entire circumference of the electronic component W (see FIG. 9).

Figure 9 shows the state in which light is irradiated directly from the third irradiation device 13 mainly onto the side surface 2 of the electronic component W.

In FIG. 9, when direct light is irradiated from the third irradiation device 13 mainly onto the side surface 2 of the electronic component W, direct reflection occurs at the defect-free portion of the side surface 2, and the directly reflected light from the side surface 2 is guided to the imaging device 20 via the reflection device 15. In this case, if a defect a3 is present on the side surface 2, the direct light from the third irradiation device 13 causes scattered reflection at the defect a3. The scattered reflected light generated at the defect a3 becomes light that scatters in all directions from the defect a3.

The direct reflected light generated by the direct light being reflected from a defect-free portion of the side surface 2 of the electronic component W is an intense light that is guided to the imaging device 20, but on the other hand, the scattered reflected light generated by the direct light being reflected from the defect a3 on the side surface 2 is hardly guided to the imaging device 20.

Similarly, when light is irradiated directly from the third irradiation device 13 mainly onto the side surface 2 of the electronic component W, reflected light occurs on parts of the top surface 1 that are free of defects, but the reflected light from the top surface 1 is not guided to the imaging device 20 via the reflection device 15. In this case, if a defect a1 exists on the top surface 1, the light from the third irradiation device 13 causes scattered reflection at the defect a1. The scattered reflected light generated by the defect a1 is scattered in all directions from the defect a1, but some of it is guided to the imaging device 20 via the reflection device 15.

The reflected light generated when the direct light is reflected from a defect-free portion of the top surface 1 of the electronic component W is not guided from the reflecting device 15 to the imaging device 20, but the scattered reflected light generated when the direct light is reflected from the defect a1 on the top surface 1 is partially guided from the reflecting device 15 to the imaging device 20.

Similarly, when light is irradiated directly from the third irradiation device 13 mainly onto the side surface 2 of the electronic component W, reflected light occurs at the portion of the ridge line 3 that is free of defects, but the reflected light from the ridge line 3 is not guided to the imaging device 20 via the reflecting device 15. In this case, if a defect a2 exists on the ridge line 3, the light from the third irradiation device 13 causes scattered reflection at the defect a2. The scattered reflected light generated at the defect a2 is scattered in all directions from the defect a2, but some of it is guided to the imaging device 20 via the reflecting device 15.

In this way, the direct reflected light generated by reflection from a defect-free portion of the edge line 3 of the electronic component W is not guided from the reflecting device 15 to the imaging device 20, but a portion of the scattered reflected light generated by reflection from the defect a2 of the edge line 3 is guided from the reflecting device 15 to the imaging device 20.

As described above, by irradiating light directly from the third irradiation device 13 mainly onto the side surface 2 of the electronic component W, mainly direct reflection occurs in defect-free parts of the side surface 2 of the electronic component W, and mainly diffuse reflection occurs in defective parts of the top surface 1 and the ridge line 3. The direct reflected light and diffuse reflected light generated by the direct reflection and diffuse reflection become the third reflected light and are sent to the imaging device 20 via the reflection device 15 (see Figure 6).

Next, the imaging device body 21 of the imaging device 20 receives the third reflected light generated by reflection from the top surface 1, the ridge 3, and the side surface 2 of the electronic component W, and obtains a third image (see FIG. 5).

The third image from the imaging device 20 is then sent to the image processing device 25. As described above, by irradiating the side surface 2 with direct light from the third irradiation device 13, the direct reflected light from the defect-free portion of the side surface 2 is sent to the imaging device 20 via the reflecting device 15, and the scattered reflected light generated by the defect a3 on the side surface 2 is hardly sent from the reflecting device 15 to the imaging device 20.

As a result, in the third image, the non-defective parts of side 2 appear bright, but defect a3 on side 2 appears clearly black.

In this way, the image processing device 25 can clearly detect the defect a3 on the side surface 2 in the third image.

On the other hand, in the third image, the reflected light from the defect-free parts of the upper surface 1 is not guided from the reflecting device 15 to the imaging device 20, and so appears dark. On the other hand, part of the scattered reflected light generated by the defect a1 on the upper surface 1 is guided from the reflecting device 15 to the imaging device 20, so the defect a1 on the upper surface 1 appears slightly brighter.

In this way, the image processing device 25 can detect the defect a1 on the upper surface 1 in the third image with a certain degree of certainty.

Similarly, in the third image, reflected light from a non-defective portion of ridgeline 3 is not guided from reflecting device 15 to imaging device 20, and so appears dark. A portion of the scattered reflected light generated by defect a2 on ridgeline 3 is guided from reflecting device 15 to imaging device 20, so defect a2 on ridgeline 3 appears slightly brighter.

In this way, the image processing device 25 can detect the defect a2 on the edge line 3 in the third image with a certain degree of certainty.

As described above, according to this embodiment, the first image is obtained by irradiating the electronic component W directly with light from the first irradiation device 11, and the image processing device 25 can accurately detect the defect a1 on the top surface 1 that appears clearly in this first image. At the same time, the image processing device 25 can also detect the defect a2 on the edge line 3 and the defect a3 on the side surface 2 with a certain degree of accuracy.

In addition, a second image is obtained by irradiating the electronic component W directly with light from the second irradiation device 12, and the image processing device 25 can accurately detect the defect a2 on the edge line 3 that appears clearly in this second image. At the same time, the image processing device 25 can also detect the defect a1 on the top surface 1 and the defect a3 on the side surface 2 with a certain degree of accuracy.

In addition, a third image is obtained by irradiating the electronic component W directly with light from the third irradiation device 13, and the image processing device 25 can accurately detect the defect a3 on the side surface 2 that appears clearly in this third image. At the same time, the image processing device 25 can also detect the defect a1 on the top surface 1 and the defect a2 on the edge line 3 with a certain degree of accuracy.

The image processing device 25 then performs binarization processing on each of the obtained first image, second image, and third image.

Here, binarization refers to a process in which, for example, the brightest part of an image is set to 100%, the darkest part to 0%, the brightness of other parts is specified in the range of 0-100%, and parts with a brightness of 0% or less and less than 50% are set to dark parts, and parts between 50% and 100% are set to light parts.

In the image processing device 25, the first image, the second image, and the third image are subjected to the binarization process described above.

In this embodiment, a reference data pattern is stored in advance in the image processing device 25 by performing binarization processing on each of the first image, second image, and third image obtained from a reference electronic component. This reference data pattern includes binarized data of the first image, binarized data of the second image, and binarized data of the third image.

This reference data pattern is shown in Figure 6. In the reference data pattern shown in Figure 6, the defect-free areas of the top surface 1 in the first image are mainly bright areas (100%) due to direct reflected light, while the defect-free areas of the ridges 3 and side surfaces 2 are mainly dark areas (0%) due to scattered reflected light.

Furthermore, in the first image, defect a1 on top surface 1 appears as 0%, defect a2 on edge 3 appears as 100%, and defect a3 on side surface 2 appears as 100%.

In addition, in the second image, the ridge line 3 appears bright (100%) in areas without defects due to mainly direct reflected light, while the top surface 1 and side surface 2 appear dark (0%) in areas without defects due to mainly diffuse reflected light.

In this second image, defect a2 on edge 3 appears as 0%, defect a1 on top surface 1 appears as 100%, and defect a3 on side surface 2 appears as 100%.

Furthermore, in the third image, the side surface 2 appears bright (100%) in areas without defects due to mainly direct reflected light, while the top surface 1 and ridge line 3 appear dark (0%) in areas without defects due to mainly diffuse reflected light.

Furthermore, in the third image, defect a3 on side surface 2 appears as 0%, defect a1 on top surface 1 appears as 100%, and defect a3 on side surface 2 appears as 100%.

On the other hand, as described above, the image processing device 25 performs binarization processing on each of the first image, second image, and third image obtained by the imaging device 20 by performing a visual inspection on the electronic component W to be inspected. This makes it possible to obtain an inspection data pattern corresponding to the reference data pattern shown in FIG. 6. In this embodiment, the inspection data pattern includes binarized data of the first image, second image, and third image obtained by actually performing a visual inspection on the electronic component W.

The image processing device 25 then compares the obtained test data pattern with the reference data pattern.

As described above, defect a1 on top surface 1 in the reference data pattern is represented as 0% on the first image, 100% on the second image, and 100% on the third image.

On the other hand, if the inspection data pattern obtained by inspecting the electronic component W to be inspected shows defect a1 on top surface 1 as 0% on the first image, 100% on the second image, and 100% on the third image, then since the inspection data pattern for defect a1 on top surface 1 corresponds to the reference data pattern, it can be verified that defect a1 on top surface 1 obtained from the electronic component W to be inspected has been correctly detected.

In contrast, if there is a difference between the reference data pattern and the inspection data pattern for defect a1 on top surface 1, defect a2 on edge 3, or defect a3 on side surface 2, it is possible to check again whether the defect obtained from the electronic component W to be inspected has been correctly detected. For example, if in the inspection data pattern defect a1 on top surface 1 is 0% on the first image, but is also 0% on the second and third images, the detection accuracy of defect a1 on top surface 1 can be checked again because defect a1 on top surface 1 is not 0% on the first image, 100% on the second image, and 100% on the third image as in the reference data pattern.

If defect a1 on top surface 1 is not a normal defect, but a black foreign object, chip, or bulge that has turned black, defect a1 on top surface 1 may be shown as 0% on the first image and may also be shown as 0% on the second and third images, making it possible to identify the characteristics of defect a1 in this case (black foreign object, chip, etc.). Alternatively, if defect a1 on top surface 1 is shown as 0% on the first image and shown as 100% on the second and third images, it is possible to reliably detect defect a1 shown as 100% on the second and third images even if defect a1 that is 0% on the first image is overlooked.

According to this embodiment, the image processing device 25 compares a reference data pattern obtained in advance with an inspection data pattern obtained by performing a visual inspection on the electronic component W to be inspected. Then, by verifying whether the reference data pattern and the inspection data pattern match, it is possible to accurately detect the defect a1 on the top surface 1, the defect a3 on the edge line 3, or the defect a2 on the side surface 2 obtained by inspecting the electronic component W to be inspected.

Next, the image processing device 25 combines the obtained first, second, and third images (see FIG. 2). As described above, the light irradiated from the first irradiation device 11 to the electronic component W, the light irradiated from the second irradiation device 12 to the electronic component W, and the light irradiated from the third irradiation device 13 are each light of a different color, for example, blue light, green light, and red light.

As shown in FIG. 2, the first image, the second image, and the third image combined in the image processing device 25 are images with different colors, so that the defects detected in the first image, the defects detected in the second image, and the defects detected in the third image can be recognized separately in the combined image.

As described above, according to this embodiment, the first image is obtained by irradiating the electronic component W directly with light from the first irradiation device 11, and the image processing device 25 can accurately detect the defect a1 on the top surface 1 that appears clearly in this first image.

In addition, a second image is obtained by irradiating the electronic component W directly with light from the second irradiation device 12, and the defect a2 on the edge line 3 that appears clearly in this second image can be detected with high accuracy by the image processing device 25.

In addition, a third image is obtained by irradiating the electronic component W directly with light from the third irradiation device 13, and the defect a3 on the side surface 2 that appears clearly in this third image can be detected with high accuracy by the image processing device 25.

In this way, in the image processing device 25, defect a1 on the top surface 1 can be reliably detected based on the first image obtained by irradiating light from the first irradiation device 11, defect a2 on the ridge line 3 can be reliably detected based on the second image obtained by irradiating light from the second irradiation device 12, and defect a3 on the side surface 2 can be reliably detected based on the third image obtained by irradiating light from the third irradiation device 13.

In addition, according to this embodiment, the image processing device 25 compares a reference data pattern obtained in advance with an inspection data pattern obtained by performing a visual inspection on the electronic component W to be inspected. Then, by verifying whether the reference data pattern and the inspection data pattern correspond to each other, it is possible to accurately detect the defect a1 on the top surface 1, the defect a3 on the edge line 3, or the defect a2 on the side surface 2 obtained by inspecting the electronic component W to be inspected.

In this case, the reference data pattern and the inspection data pattern each have a first image including a top surface 1 obtained primarily by direct reflection light and a ridge line 3 and a side surface 2 obtained primarily by scattered reflection light, a second image including a ridge line 3 obtained primarily by direct reflection light and a top surface 1 and a side surface 2 obtained primarily by scattered reflection light, and a third image including a side surface 2 obtained primarily by direct reflection light and a top surface 1 and a ridge line 3 obtained primarily by scattered reflection light.

In this way, the image processing device 25 uses a reference data pattern obtained from direct reflected light and scattered reflected light and an inspection data pattern obtained from direct reflected light and scattered reflected light, and compares the two to verify the accuracy of defects a1, a2, and a3 obtained by inspecting the electronic component to be inspected. In this way, by using both direct reflected light and scattered reflected light, defects a1, a2, and a3 obtained by inspecting the electronic component to be inspected can be verified, and these defects a1, a2, and a3 can be reliably detected.

According to this embodiment, four reflecting devices 15 are provided on the four sides of the top surface 1 of the rectangular parallelepiped electronic component W, i.e., on the outer upper side of the four sides of the top surface 1 in correspondence with the four ridgelines 3. This allows accurate and reliable detection of defects a1, a2, and a3 present on the ridgelines 3 and on the top surface 1 and side surface 2 near each ridgeline 3 over the four sides of the top surface 1 of the electronic component W, i.e., the entire circumference of the four ridgelines 3. Alternatively, if the reflecting devices 15 are provided at four additional locations above the outer sides of the four corners of the top surface 1, for a total of eight locations, it is possible to accurately and reliably detect defects a1, a2, and a3 present on the ridgelines 3 and on the top surface 1 and side surface 2 near each ridgeline 3 over the four sides of the top surface 1 of the electronic component W, i.e., the four ridgelines and the four corners.

Next, we will further explain the specific operation of this embodiment.

First, the electronic component W to be inspected is placed on the glass plate that constitutes the table 14.

Then, as shown in FIG. 1A, the first irradiation device 11 directly irradiates the top surface 1 of the electronic component W, and the reflected light that mainly contains a large amount of direct reflection components is reflected from the top surface 1, and the reflected light that mainly contains a large amount of scattered reflection components is reflected from the ridges 3 and side surfaces 2.

The second irradiation device 12 directly irradiates the ridge 3 of the electronic component W, and reflected light containing a large amount of direct reflection components is reflected from the ridge 3, while reflected light containing a large amount of mainly scattered reflection components is reflected from the top surface 1 and side surface 2. The third irradiation device 13 directly irradiates the side surface 2 of the electronic component W, and reflected light containing a large amount of mainly direct reflection components is reflected from the side surface 2, while reflected light containing a large amount of mainly scattered reflection components is reflected from the top surface 1 and the ridge 3.

The reflected component is expressed, for example, by the following formula, and the coefficients Ka, Kd, and Ks are determined depending on the material and surface condition.
I = K a I a + I i (K d cos α + K s cos nr )

Here, KaIa is the ambient component, Kdcosα is the scattered component, and Kscosnr is the direct reflection component.

For example, if a defect a1 occurs on the top surface 1 of the electronic component W, when light is irradiated from the first irradiation device 11 onto the electronic component W, the reflection direction of the direct reflection at the defect a1 of the electronic component W is disturbed, and less light passes through the reflecting device 15 such as a mirror and enters the imaging device 20, so that the defect a1 of the electronic component W shown in the first image appears black.

When light is irradiated from the second irradiation device 12 onto the electronic component W, the reflection angle at the defect a1 in the electronic component W changes, resulting in scattered reflected light including the reflection direction of direct reflection. As a result, more light passes through the reflecting device 15, such as a mirror, and enters the imaging device 20, so that the defect a1 in the electronic component W shown in the second image appears light gray.

When light is irradiated from the third irradiation device 13 onto the electronic component W, the light that passes through the reflecting device 15, such as a mirror, from the defect a1 in the electronic component W and enters the imaging device 20 is reflected in a scattered manner that includes a direct reflection direction, and the defect a1 in the electronic component that appears in the third image appears light gray.

For example, if defect a2 occurs on edge line 3 of electronic component W, when light is irradiated from first irradiation device 11 onto electronic component W, the reflection angle of defect a2 in electronic component W changes, resulting in scattered reflected light including the reflection direction of direct reflection, and more light passes through reflection device 15 such as a mirror and enters imaging device 20. For this reason, defect a2 in electronic component W appears light gray in the first image.

In addition, when light is irradiated from the second irradiation device 12 onto the electronic component W, the reflection direction of the direct reflection is disturbed at the defect a2 in the electronic component W, and less light passes through the reflecting device 15, such as a mirror, and enters the imaging device 20, so that the defect a2 in the electronic component W shown in the second image appears black.

In addition, when light is irradiated from the third irradiation device 13 onto the electronic component W, the reflection angle changes at the defect a2 in the electronic component W, resulting in scattered reflected light including the reflection direction of direct reflection. As a result, more light passes through the reflecting device 15, such as a mirror, and enters the imaging device 20, so the defect a2 in the electronic component W that appears in the third image appears light gray.

For example, if a defect a3 occurs on the side surface 2 of the electronic component W, when light is irradiated from the first irradiation device 11 onto the electronic component W, the angle of reflection changes at the defect a3 of the electronic component W, resulting in scattered reflected light including the reflection direction of direct reflection. This scattered reflected light passes through a reflecting device 15 such as a mirror and enters the imaging device 20, so that the defect a3 of the electronic component W shown in the first image appears light gray.

When light is irradiated from the second irradiation device 12 onto the electronic component W, the reflection angle changes at defect a3 in the electronic component W, resulting in scattered reflected light including the reflection direction of direct reflection. The scattered reflected light that passes through a reflecting device 15 such as a mirror and enters the imaging device 20 causes defect a3 in the electronic component W to appear light gray in the second image.

When light is irradiated onto the electronic component W from the third irradiation device 13, the reflection direction of the direct reflection is disturbed at the defect a3 in the electronic component W, and less light passes through the reflecting device 15, such as a mirror, and enters the imaging device 20, so that the defect a3 in the electronic component W appears black in the third image.

The first, second, and third images thus obtained are then subjected to the binarization process described above to obtain an inspection data pattern, and the inspection data pattern thus obtained is compared with a previously determined reference data pattern to verify the detection accuracy of defects a1, a2, and a3 in the first, second, and third images.

<Modification>
Next, modified examples of the present disclosure will be described with reference to Fig. 12 to Fig. 15. Fig. 12 is a diagram showing a modified example of an appearance inspection apparatus for electronic components according to the present disclosure, which is a diagram showing an ideal boundary between an electronic component body and an electrode obtained by combining a first image, a second image, and a third image, Fig. 13 is a diagram showing a distorted boundary between an electronic component body and an electrode obtained by combining a first image, a second image, and a third image, Fig. 14A is a diagram showing a combination of a first image, a second image, and a third image for opposing ridgelines, Fig. 14B is a diagram showing a combination of a first image, a second image, and a third image for one ridgeline, and Fig. 15 is a diagram comparing grayscale images for a pair of opposing ridgelines.
Of these, Fig. 12 is a diagram combining the first image, the second image, and the third image obtained by imaging an electronic component W having an electronic component body W1 and a pair of electrodes W2, W2 provided on both sides of the electronic component body W1, respectively, in grayscale. In Fig. 12, the electronic component W is shown as seen from diagonally above the ridge line 3.

As shown in FIG. 12, an ideal boundary line L1 perpendicular to the ridge line 3 is formed between the electronic component body W1 of the electronic component W and the pair of electrodes W2, W2.

In FIG. 12, electronic component W has a black defect a1 on the top surface 1 of electrode W2, which is shown in white, and a white defect a3 on the side surface 2 of electronic component body W1, which is shown in black. However, in reality, when the first image, second image, and third image are binarized and combined, electronic component body W1 appears black overall, and electrodes W2, defect a1 in W2 are also shown in black. Then, electrodes W2, W2 appear white overall, and defect a3 in electronic component body W1 also appears white.

In this case, the boundary line L2 between the electronic component body W1 and the electrode w2 is shown distorted and not perpendicular to the edge line 3 due to the defect a1 shown in black and the defect a3 shown in white, and in this case, the black defect a1 and the white defect a3 are overlooked.

In this modified example, the first, second, and third grayscale images obtained by imaging the vicinity of one edge line 3 of the electronic component W are combined (see FIG. 14A). Next, the first, second, and third grayscale images obtained by imaging the vicinity of the other edge line 3A of the electronic component W are combined (see FIG. 14B). In FIGS. 14A and 14B, the other edge line 3A is formed between the top surface 1 and the other side surface 2A. Next, an image (see FIG. 14A) obtained by combining the grayscale images of the first, second, and third images obtained by imaging the vicinity of one edge line 3 of the electronic component W and an image (see FIG. 14B) obtained by combining the grayscale images of the first, second, and third images obtained by imaging the vicinity of the other edge line 3A of the electronic component W are brought close to each other, and image processing is performed so that the combined grayscale image near one edge line 3 of the electronic component W and the combined grayscale image near the other edge line 3A overlap each other (see FIG. 14A).

Next, as shown in FIG. 15, the correlation between an image (see FIG. 14A) obtained by combining the grayscale images of the first, second, and third images obtained by capturing the vicinity of one edge line 3 of the electronic component W and an image (see FIG. 14B) obtained by combining the grayscale images of the first, second, and third images obtained by capturing the vicinity of the other edge line 3A of the electronic component W is compared. This allows for identifying locations with low and different correlations around the boundary line L1 between the electronic component body W1 and the electrode W2 with respect to one edge line 3, and thus allows for the defect a1 on the top surface 1 of the electrode W2 and the defect a3 on the side surface of the electronic component body W1 with respect to one edge line 3 to be correctly recognized and detected.

REFERENCE SIGNS LIST 1 Upper surface 2 Side surface 2A Other side surface 3 Ridge line, one ridge line 3A Other ridge line 10 Appearance inspection device for electronic components 11 First irradiation device 12 Second irradiation device 13 Third irradiation device 14 Table 15 Reflection device 18a Suction nozzle 18 Conveyor device 20 Imaging device 21 Imaging device main body 22 Lens 25 Image processing device W Electronic component a1 Defect a2 Defect a3 Defect

Claims (7)

An electronic component appearance inspection apparatus for inspecting the appearance of an electronic component having at least a top surface, a side surface, and a ridge line between the top surface and the side surface, comprising:
A support portion that supports the electronic component;
a first irradiation device that irradiates a top surface of the electronic component with light to obtain a first reflected light including reflected light from the top surface of the electronic component, reflected light from the ridge line, and reflected light from the side surface;
a second irradiation device that irradiates a ridge line of the electronic component with light to obtain second reflected light including reflected light from the ridge line of the electronic component, reflected light from the top surface, and reflected light from the side surface;
a third irradiation device that irradiates a side surface of the electronic component with light to obtain a third reflected light including a reflected light from the side surface of the electronic component, a reflected light from the top surface, and a reflected light from the ridge line;
an imaging device that receives a first reflected light, a second reflected light, and a third reflected light from the electronic component to obtain a first image, a second image, and a third image;
an image processing device connected to the imaging device,
the image processing device detects defects present on the top surface, the ridge line, or the side surface based on the first image, the second image, and the third image;
a reflecting device that guides a first reflected light from the electronic component, a second reflected light from the electronic component, and a third reflected light from the electronic component to the imaging device,
the reflection device guides the directly reflected light of the light from the first irradiation device, the directly reflected light of the light from the second irradiation device, and the directly reflected light of the light from the third irradiation device to the imaging device;
The electronic component has an electronic component body and an electrode connected to the electronic component body via a boundary line,
the image processing device creates and combines grayscale image data for the top surface, the ridge line, and the side surface on the first image, grayscale image data for the top surface, the ridge line, and the side surface on the second image, and grayscale image data for the top surface, the ridge line, and the side surface on the third image for a pair of ridge lines that are perpendicular to the boundary line of the electronic component and face each other, and by bringing a grayscale image obtained by combining the grayscale images of the first, second, and third images for one ridge line and a grayscale image obtained by combining the grayscale images of the first, second, and third images for the other ridge line close to each other and comparing them, the device identifies areas where there are differences with low correlation and detects defects present on the top surface, the ridge line, or the side surface . 2. The electronic component appearance inspection apparatus according to claim 1, wherein the reflection device is arranged in plurality around the outer periphery of the electronic component, and a plurality of first images, a second image, and a third image are obtained based on the light from each of the first illumination device, the second illumination device, and the third illumination device. 2. The electronic component visual inspection apparatus according to claim 1 , wherein the reflecting device includes a mirror or a prism. The electronic component visual inspection device according to claim 1, wherein the first irradiation device emits light in a first wavelength range, the second irradiation device emits light in a second wavelength range different from the first wavelength range, and the third irradiation device emits light in a third wavelength range different from the first wavelength range and the second wavelength range. The electronic component appearance inspection device according to claim 1, wherein the imaging device has an image sensor or optical sensor that receives the first reflected light, the second reflected light, and the third reflected light to obtain a first image, a second image, and a third image. 1. A method for inspecting the appearance of an electronic component having at least a top surface, a side surface, and a ridge line between the top surface and the side surface, comprising:
a step of irradiating a top surface of the electronic component with light from a first irradiation device to obtain a first reflected light including reflected light from the top surface of the electronic component, reflected light from the ridge line, and reflected light from the side surface;
a step of irradiating a ridge line of the electronic component with light from a second irradiation device to obtain second reflected light including reflected light from the ridge line of the electronic component, reflected light from the top surface, and reflected light from the side surface;
irradiating a side surface of the electronic component with light from a third irradiation device to obtain third reflected light including reflected light from the side surface of the electronic component, reflected light from the top surface, and reflected light from the ridge line;
receiving a first reflected light, a second reflected light, and a third reflected light from the electronic component with an imaging device to obtain a first image, a second image, and a third image;
detecting defects present on the top surface, the ridge line, and the side surface based on the first image, the second image, and the third image by an image processing device ;
The method further includes a step of guiding the first reflected light from the electronic component, the second reflected light from the electronic component, and the third reflected light from the electronic component to the imaging device by a reflecting device,
the reflection device guides the directly reflected light of the light from the first irradiation device, the directly reflected light of the light from the second irradiation device, and the directly reflected light of the light from the third irradiation device to the imaging device;
The electronic component has an electronic component body and an electrode connected to the electronic component body via a boundary line,
the image processing device creates and combines grayscale image data for the top surface, the ridge line, and the side surface on the first image, grayscale image data for the top surface, the ridge line, and the side surface on the second image, and grayscale image data for the top surface, the ridge line, and the side surface on the third image for a pair of ridge lines that are perpendicular to the boundary line of the electronic component and face each other, and by bringing a grayscale image obtained by combining the grayscale images of the first, second, and third images for one ridge line and a grayscale image obtained by combining the grayscale images of the first, second, and third images for the other ridge line close to each other and comparing them, locations where there are differences with low correlation are identified and defects present on any of the top surface, the ridge line, or the side surfaces are detected . 7. The method for visual inspection of electronic components according to claim 6, wherein the first irradiation device emits light in a first wavelength range, the second irradiation device emits light in a second wavelength range different from the first wavelength range, and the third irradiation device emits light in a third wavelength range different from the first wavelength range and the second wavelength range.

Images