KR102639842B1 - System and method capable of inspecting defect of curved part or drooped part - Google Patents

Abstract

Disclosed is a defect inspection system and method that can inspect defects in curved or sagging parts of an object. A defect inspection system that inspects an object using a reflection method includes a first illumination unit that vertically injects first light into the object, a second illumination unit that diagonally injects second light into the object, and a detection unit. Here, the first light is vertically reflected from the object, the second light is diffusely reflected from the object, the detection unit detects the reflected light due to the reflection and the diffusely reflected light due to the diffuse reflection, and the first lighting unit and The second lighting unit is arranged up and down, and the sensing unit detects defects in areas where bending or sagging of the object does not occur through the reflected light, and detects defects in areas where bending or sagging of the object occurs through the diffusely reflected light. sense

Description

System and method capable of inspecting defects in curved or sagging parts {SYSTEM AND METHOD CAPABLE OF INSPECTING DEFECT OF CURVED PART OR DROOPED PART}

The present invention relates to a system and method capable of inspecting defects in bent or sagging parts.

When transporting a substrate, if it is impossible to inspect defects using transmitted lighting, inspect the substrate for defects using a reflection method using top lighting.

However, in this defect inspection method, as shown in FIG. 1, when a part of the substrate is bent or sagged due to vibration, the bent or sagging portion in the image obtained by photographing the substrate with a camera is shown in FIG. 2. It comes out black as expected. In other words, it is not possible to inspect defects in curved or sagging parts.

KR 10-2012-0035484 A

The present invention provides a defect inspection system and method that can inspect defects in curved or sagging parts of an object.

In order to achieve the above-described object, a defect inspection system for inspecting an object using a reflection method according to an embodiment of the present invention includes a first lighting unit that vertically incident first light onto the object; a second illumination unit that diagonally enters second light into the object; and a detection unit. Here, the first light is vertically reflected from the object, the second light is diffusely reflected from the object, the detection unit detects the reflected light due to the reflection and the diffusely reflected light due to the diffuse reflection, and the first lighting unit and The second lighting unit is arranged up and down, and the sensing unit detects defects in areas where bending or sagging of the object does not occur through the reflected light, and detects defects in areas where bending or sagging of the object occurs through the diffusely reflected light. sense

A defect inspection method according to an embodiment of the present invention includes the steps of incident first light perpendicularly to an object; making second light obliquely incident on the object; detecting first reflected light corresponding to first light reflected from the object and second reflected light corresponding to second light reflected from the object; and inspecting the object for defects through the detected reflected light. Here, the first light and the second light have the same wavelength, and the second light is diffusely reflected from the object, enabling defect inspection of curved or sagging portions of the object.

In the defect inspection system and method according to the present invention, the first light is incident perpendicularly to the object and the second light is incident on the object obliquely to cause diffuse reflection, so that not only the area where no bending or sagging has occurred, but also the area where the bending or sagging has occurred Defects can also be accurately inspected.

Figure 1 is a diagram showing a conventional defect inspection system.
Figure 2 is a diagram showing an image according to a conventional defect inspection method.
Figure 3 is a diagram showing a system for inspecting defective objects according to a first embodiment of the present invention.
Figure 4 is a diagram showing a defect inspection system according to a second embodiment of the present invention.
Figure 5 is a diagram showing defective inspection results.
Figure 6 is a diagram showing a defect inspection system according to a second embodiment of the present invention.

As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “consists of” or “comprises” should not be construed as necessarily including all of the various components or steps described in the specification, and some of the components or steps may be included in the specification. It may not be included, or it should be interpreted as including additional components or steps. In addition, terms such as "... unit" and "module" used in the specification refer to a unit that processes at least one function or operation, which may be implemented as hardware or software, or as a combination of hardware and software. .

The present invention relates to a system and method for inspecting defects in a display object, for example, a substrate, and can accurately detect defects in the object even if the object is curved or sagging.

In particular, the system of the present invention is suitable for inspecting defects in objects that must be inspected by reflection.

For example, the system can perform defect inspection of an object that is moved while placed on a robot arm, defect inspection of a substrate on which a metal is formed, etc. Because the majority of light does not pass through these objects, defects cannot be inspected using a transmission method and defects must be inspected using a reflection method.

In the conventional inspection method, when bending or sagging occurs in the object, defects in the area where the bending or sagging occurs are not properly detected, as shown in FIG. 2.

Therefore, the present invention proposes a system and method that can accurately detect defects in areas where bending or sagging occurs.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings.

Figure 3 is a diagram showing a defect inspection system for an object according to a first embodiment of the present invention, Figure 4 is a diagram showing a defect inspection system according to a second embodiment of the present invention, and Figure 5 is a diagram showing the defect inspection result. This is a drawing. For convenience of explanation, it is assumed that the object 302 is placed on the robot arm 300.

Referring to FIG. 3, the defect inspection system of this embodiment includes a first lighting unit 304, a second lighting unit 306, and a detection unit 308.

The first lighting unit 304 outputs light perpendicular to the object 302, for example, the substrate, and may be arranged below the sensing unit 308.

This first lighting unit 304 may include a first body 310, a first light source 312, and a half mirror 314.

Additionally, a portion of the first body 310 directly below the sensing unit 308, that is, a portion facing the sensing unit 308, may be made of transparent glass 316. Reflected light is transmitted to the sensing unit 308 through the glass 316. Of course, it may be made of a hole instead of the glass 316, but if it is made of a hole, it is not efficient because dust, etc. may penetrate into the first lighting unit 304 and the second lighting unit 306.

The first light source 312 is formed on an inner portion of the first body 310, preferably on the side, and may be, for example, an LED.

The half mirror 314 is arranged below the glass 316 and reflects light incident from the first light source 312 toward the object 302 as shown in FIG. 3 . In this case, the light reflected by the half mirror 314 is incident perpendicularly to the object 302, and as a result, the light reflected from the object 302 is directed in a direction perpendicular to the object 302, that is, the half mirror 314 Proceed in the direction of Some of the reflected light incident on the half mirror 314 passes through the half mirror 314 and is incident on the detection unit 308.

The second lighting unit 306 is a light used to inspect defects in a bent or sagging portion of the object 302, and includes a second body 320, second lights 324a and 324b, and a dome-shaped reflector. It may include fields 322a and 322b.

For example, the second body 320 may have a rectangular parallelepiped shape with holes formed at the top and bottom. The holes formed at the top and bottom may be arranged, for example, side by side, corresponding to the glass 316 of the first lighting unit 304. As a result, the holes of the second lighting unit 306, the glass 316, and the sensing unit 308 can be arranged vertically. This is so that the reflected light reflected from the object 302 is received by the sensing unit 308.

The first body 310 may be placed on the second body 320.

The second lights 324a and 324b may be placed on the bottoms of the second body 320 and are, for example, LEDs.

The first reflector 322a may be arranged to correspond to the second lighting 324a, and the second reflector 322b may be arranged to correspond to the second lighting 324b. As a result, the light output from the second illumination 324a is reflected by the first reflector 322a and then enters the object 302 through the lower hole, and the light output from the second illumination 322b is reflected by the second reflector 322a. After being reflected by the reflector 322b, it may be incident on the object 302 through the lower hole.

The reflectors 322a and 322b incident on the object 302 are diffusely reflected, and the diffusely reflected light passes through the holes of the second body 320, the half mirror 314, and the glass 316 of the first lighting unit 304. is incident on the detection unit 308.

Below, we will look at the inspection process of a defect inspection system with this structure.

First, the first light 312 may output first light, and the second lights 324a and 324b may output second light.

According to one embodiment, the first light and the second light may be output at the same time and have the same wavelength. If the first light and the second light have different wavelengths, the detection unit 308, for example, a camera, cannot focus and must use a plurality of detection units. Accordingly, the defect inspection system of the present invention can use the first light and the second light of the same wavelength to use one detection unit 308.

Assuming that the intensity of the first light is 80 when only the first light 312 is used and that the intensity of the second light is 100 when only the second lights 324a and 324b are used, the first light 312 and the second lights When 324a and 324b are used together, the intensities of the first light and the second light may be, for example, 50 and 100, respectively.

That is, when inspecting defects using the first light 312 and the second lights 324a and 324b together, the intensity of the first light output from the first light 312 is lower than the intensity of the first light 312 when inspecting the object using only the first light 312. When inspecting 302 , the intensity of the first light output from the first illumination 312 may be smaller than that of the first light. This is because the first light is influenced by the second light output from the second lights 324a and 324b.

In the image, as shown in FIG. 5, the first light output from the first light 312 and the second light output from the second lights 324a and 324b so that light of similar intensity is incident on the entire object 302. The intensity of light can be adjusted. For example, in the right image of FIG. 5 , the difference in brightness between the bright portion corresponding to the first light 312 and the bright portion corresponding to the second lights 324a and 324b may be 3% or less.

Subsequently, some of the first light is reflected by the half mirror 314 and then enters the object 302 through the holes of the second lighting unit 306, and the first reflected light reflected from the object 302 is transmitted to the second lighting unit 306. It may enter the detection unit 308 through the holes of 306, the half mirror 314, and the glass 316 of the first lighting unit 304.

Additionally, the second light is reflected by the reflectors 322a and 322b and then enters the object 302 through the lower hole. At this time, the light reflected by the reflectors 322a and 322b is not incident perpendicularly but at an angle, as shown in FIG. 3, and as a result, the light is diffusely reflected from the object 302. The diffusely reflected light (second reflected light) may be incident on the sensing unit 308 through the holes of the second lighting unit 306, the half mirror 314, and the glass 316 of the first lighting unit 304.

That is, the detection unit 308 detects the reflected light that is perpendicularly incident and reflected on the object 302 by the first light 312 and the light output from the second lights 324a and 324b and diffusely reflected from the object 302. Receive. At this time, the inspection unit (not shown) can acquire one image (right image in FIG. 5) through the received reflected light and diffusely reflected light.

In theory, this image may correspond to an image that is a combination of an image corresponding to the reflected light (left image in FIG. 5) and an image corresponding to the diffusely reflected light (middle image in FIG. 5). Specifically, the black portion in the left image of FIG. 5 and the bright portion in the middle image are areas where bending or sagging occurs, and therefore the object 302 is formed bright overall in the image including both the left image and the middle image. That is, the inspection unit can inspect all defects in areas where bending or sagging has occurred as well as areas where bending or sagging has occurred through the final image.

In summary, the defect inspection system of this embodiment acquires images using the first lighting unit 304 and the second lighting unit 306, and through the images, not only defects in areas where bending or sagging do not occur, but also bending or sagging are detected. Defects in the area where this occurred can also be inspected. At this time, the first lighting unit 304 can clearly show the image of the area where bending or sagging has not occurred, and the second lighting unit 306 can clearly show the image of the area where bending or sagging has occurred, resulting in Using the lighting units 304 and 306, it is possible to inspect not only defects in areas where bending or sagging has not occurred, but also defects in areas where bending or sagging has occurred.

From above, the first lighting unit 304 is arranged above the second lighting unit 306, but the second lighting unit 306 may be arranged above the first lighting unit 304. In this case, glass may be formed without a hole being formed in the upper part of the second lighting unit 306, and a hole may still be formed in the lower part of the second lighting unit 306 and the glass 316 of the first lighting unit 304 may be formed. It can be replaced alone.

In addition, although the defect inspection system inspects defects in the moving object 302 above, it can also inspect defects in the fixed object 302. In this case, the process of acquiring the first image through the first light output from the first lighting unit 304 and the process of acquiring the second image through the second light output from the second lighting unit 306 are performed separately. Then, defects in the object 302 can be inspected by combining the acquired images. Of course, in this case, the first lighting unit 304 and the second lighting unit 306 may output light at the same time to inspect defects.

According to another embodiment, as shown in FIG. 4, the sensing unit may be located on the side of the first lighting unit and the first light of the first lighting unit may be located at the top of the inside of the first lighting unit, and the glass of the first lighting unit may be may be formed on the side to correspond to the sensing unit. However, the defect inspection process in this system is similar to the inspection process in the above embodiment.

Figure 6 is a diagram showing a defect inspection system according to a second embodiment of the present invention.

Referring to FIG. 6 , the defect inspection system of this embodiment may include a first lighting unit, a second lighting unit, and a detection unit 308 having the same structure as the first embodiment, as well as an additional transmitted lighting 600.

Additional transmitted lighting 600 may be located below the object 302. This includes an area where the object 302 can partially transmit, and therefore additional transmitted illumination 600 is used to inspect this transparent area.

Specifically, the third light output from the additional transmitted light 600 passes through the object 302 and enters the detection unit 308. Therefore, the defect inspection method of this embodiment can inspect defects of not only objects that do not include a transparent area but also objects that include a transparent area.

Meanwhile, the components of the above-described embodiment can be easily understood from a process perspective. In other words, each component can be understood as a separate process. Additionally, the processes of the above-described embodiments can be easily understood from the perspective of the components of the device.

Additionally, the technical contents described above may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc., singly or in combination. Program instructions recorded on the medium may be specially designed and configured for the embodiments or may be known and available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -Includes optical media (magneto-optical media) and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. Examples of program instructions include machine language code, such as that produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc. A hardware device may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

The above-described embodiments of the present invention have been disclosed for illustrative purposes, and those skilled in the art will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions will be possible. should be regarded as falling within the scope of the patent claims below.

300: Robotic arm 302: Object
304: first lighting unit 306: second lighting unit
310: first body 312: first light
314: half mirror 320: second body
322a, 322b: reflector 324a, 324b: second light

Claims (10)

In a defect inspection system that inspects an object using a reflection method,
a first illumination unit that incident first light perpendicularly to the object;
a second illumination unit that diagonally enters second light into the object; and
Including a sensing unit,
The first light is vertically reflected from the object, the second light is diffusely reflected from the object, and the detection unit detects reflected light due to the reflection and diffusely reflected light due to the diffuse reflection,
The first lighting unit and the second lighting unit are arranged up and down, and the sensing unit detects defects in areas where bending or sagging of the object does not occur through the reflected light and detects the bending or sagging of the object through the diffusely reflected light. Detect defects in the area where they occur,
The first lighting unit includes a first body, a first light, and a half mirror, and the second lighting unit includes a second body, a second light, and a dome-shaped reflector, and the sensing unit, the first lighting unit, and the dome-shaped reflector. The second lighting unit and the object are arranged vertically,
A region of the first body facing the sensing unit is formed of transparent glass, and regions of the second body facing the glass are formed alone,
The first light output from the first illumination is reflected by the half mirror and then vertically incident on the object through the holes of the second body, and the reflected light reflected by the object is reflected by the holes, the half mirror, and It is incident on the sensing unit through the glass, and when the first light passes through the second body, it is incident on the object without passing through the reflector,
The second light output from the second illumination is reflected by the reflector and then obliquely incident on the object through the lower hole of the second body and is diffusely reflected. The diffusely reflected light is reflected by the holes, the half mirror, and the second body. A defect inspection system characterized in that incident light enters the detection unit through the glass. The defect inspection method of claim 1, wherein the first light and the second light have the same wavelength, and the first lighting unit and the second lighting unit simultaneously output the first light and the second light. system. delete The method of claim 1, wherein when inspecting a defect in the object using both the first light and the second light, the intensity of the first light output from the first illumination is such that only the light output from the first illumination is inspected. A defect inspection system characterized in that the intensity of the first light when used is smaller than that of the first light. delete The method of claim 1, wherein the object is a substrate placed on a robot arm or coated with metal,
A defect inspection system, characterized in that the defect inspection is performed while the object is moving. According to paragraph 1,
It further includes additional transmitted lighting arranged at the bottom of the object,
A defect inspection system, wherein the third light output from the additional transmitted illumination passes through the object and enters the detection unit. delete delete delete