KR100839915B1 - Optical inspection system - Google Patents

Abstract

The present invention relates to an inspection system for inspecting the appearance of an inspection object (printed circuit board) using an optical method. The optical inspection system of the present invention includes a camera for imaging the surface of the inspection object, at least two illuminations for irradiating light to the imaging area of the inspection object to be imaged by the camera, and vertical light reflected from the imaging area and incident vertically into the camera. And a blocking member for blocking the non-vertical light so as not to collide with the non-vertical light emitted from the at least two lights.

Optical inspection system, lighting, camera

Description

Optical inspection system {OPTICAL INSPECTION SYSTEM}

1 is a schematic configuration diagram of an optical inspection system using conventional coaxial fall illumination.

2 is a block diagram of an optical inspection system according to the present invention.

3 is a view for schematically explaining a light path in the optical inspection system of the present invention.

4 is a view for explaining a blocking plate that can be rotated in the optical inspection system of the present invention.

5 is a view showing an example provided with a rotatable blocking member in the optical inspection system of the present invention.

6 is a view showing an example provided with a blocking plate having a vertical inner surface in the optical inspection system of the present invention.

Explanation of symbols on the main parts of the drawings

110: camera

120: lights

122: casting name

130: blocking member

132: support plate

134: blocking plate

135: outer side

The present invention relates to an optical inspection system, and more particularly to an inspection system for inspecting the appearance of an inspection object (printed circuit board) using an optical method.

In recent years, printed circuit boards, which are one of the main materials used in various semiconductor integrated circuits such as LCD driver ICs, memory and LSIs, and micro products, have been manufactured in the form of films and tapes. .

Among these printed circuit boards, a circuit commonly referred to as a tape automatic bonding (TAB) or a chip on film (COF) substrate is used. Printed circuit boards in the form of films and tapes are formed through manufacturing processes such as exposure and development. These patterns are extremely miniaturized as semiconductor devices become increasingly miniaturized, making it difficult to inspect pattern defects through human eyes. The situation is getting worse. Therefore, it is necessary to introduce an optical inspection system to accurately and quickly detect printed circuit boards, which are raw materials for forming patterns, and defects in patterns formed on printed circuit boards.

In general, the optical inspection system performs an optical inspection by using a camera, an image sensor, etc. At this time, the optical automatic inspection system uses various lighting devices to highlight the defects on the appearance of the printed circuit board to perform accurate inspection. The selection of one of the various lighting devices is essential for accurate failure detection. In particular, coaxial fall illumination has been used to inspect products whose surfaces such as COFs for driving integrated circuits of liquid crystal display devices are shining like mirrors.

However, the optical inspection system 1 using coaxial fall illumination has the following problems. As shown in FIG. 1, the coaxial fall illumination 2 has a reflector 3 that refracts light coming from the side toward the inspection object (product) 10, which reflects the light of the illumination 2. In the process of refracting toward the inspection object 10, the amount of light loss occurs. In addition, since the image pickup device 8 (LINE CCD SENSOR through the lens) sees an image through the reflecting mirror 3 of coaxial falloff illumination, the phenomenon of refraction caused by the reflecting mirror 3 is generated and the focus is shifted.

An object of the present invention is to optically inspect the defects of the light incident from multiple angles through the image pickup device to receive only the components of the light whose defect shape is well highlighted from the imaging device and to inspect the desired defects to increase the inspection reliability. To provide a system.

Still another object of the present invention is to provide an optical inspection system having an illumination device capable of obtaining a clear image.

Still another object of the present invention is to provide an optical inspection system for enhancing inspection reliability by highlighting a defective shape on the surface of the inspection object.

According to one aspect of the present invention for achieving the above object, an optical inspection system for optically inspecting the surface of the inspection object includes a camera for imaging the surface of the inspection object; At least two lights for irradiating light to an imaging area of the inspection object to be picked up by the camera; And blocking the non-vertical light so that the vertical light reflected from the imaging area and vertically incident to the camera does not collide with the non-vertical light emitted from the at least two lights, and reflects some non-vertical light. It includes a blocking member for changing to a vertical component.

In a preferred embodiment of this aspect, the at least two illuminations are cast name which is installed to irradiate light at a first angle on the surface of the imaging area of the inspection object; And auxiliary lights installed to radiate light at an inclination angle smaller than the first angle of the casting name.

In a preferred embodiment of this aspect, the cast name is located closer to the imaging area than the auxiliary lights, and the casting name and the auxiliary lights are sequentially lowered as they are farther from the imaging area.

In a preferred embodiment of this aspect, the blocking member may comprise a blocking plate located between the path through which the vertical light passes and the at least two lights, the blocking plate being irradiated from the at least two lights. It has an outer surface for guiding light to be irradiated to the imaging area.

In a preferred embodiment of this aspect, the blocking plate has an outer surface for guiding light emitted from the auxiliary lights to be irradiated to the imaging area, and the outer surface of the blocking plate is a reflective surface.

In a preferred embodiment of this aspect, the outer surface of the blocking plate may be inclined to face the imaging area.

In a preferred embodiment of this feature, the blocking member may further include a hinge portion provided on the blocking plate to adjust the angle of the light guided to the imaging area along the outer surface of the blocking plate.

In a preferred embodiment of this feature, the blocking member is installed on the blocking plate, and further includes a support plate on which the casting name and the auxiliary lights are installed.

In a preferred embodiment of this feature, the support plate is rotatably installed to adjust the irradiation angle of the cast name and the auxiliary lights.

In a preferred embodiment of this feature, the cast name and the auxiliary lights are rotatably installed on the bottom of the support plate (to adjust the irradiation angle).

In a preferred embodiment of this aspect, the angle of inclination of the first angle of the cast name and the outer surface of the blocking plate is preferably 75 ° to 90 ° with the surface of the imaging area.

According to another aspect of the present invention for achieving the above object, an optical inspection system for optically inspecting the surface of the inspection object includes a camera for imaging the surface of the inspection object; Illuminations for irradiating light to an imaging area of the inspection object to be imaged by the camera; And a blocking member configured to provide a vertical region such that only vertical lights from among lights reflected and reflected by the imaging region of the inspection object are incident on the camera.

In a preferred embodiment of the present feature, the blocking member includes an outer area where the lights are located and the light of the lights is provided to the imaging area of the inspection object, and a blocking plate for partitioning the vertical area.

In a preferred embodiment of this aspect, the blocking plate comprises an outer surface consisting of a reflective surface; The outer surface of the blocking plate is formed to be inclined so that the light irradiated to the outer surface of the blocking plate among the light emitted from the lights is guided to the imaging area.

In a preferred embodiment of the present invention, the lights are located closest to the imaging area of the inspection object, the cast name for irradiating light to the imaging area at a first angle; And auxiliary lights irradiating light to the imaging area at an inclination angle smaller than the first angle of the casting name.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the invention to those skilled in the art. Accordingly, the shape of the elements in the drawings and the like are exaggerated to emphasize a clearer description.

An embodiment of the present invention will be described in detail with reference to FIGS. 2 to 6. In addition, in the drawings, the same reference numerals are denoted together for components that perform the same function.

The basic intention of the present invention is to provide an optical inspection system capable of accurate and clear imaging by irradiating uniform light on the surface of an inspection object whose surface is shiny like a mirror (a printed circuit board, commonly referred to as a COF substrate). To this end, the present invention has a feature of having a blocking member for blocking the vertical light provided to the camera from colliding with the other light among the light that is irradiated to the image pickup area of the inspection object.

2 is a configuration diagram of an optical inspection system according to the present invention, Figure 3 is a view for schematically explaining the light path in the optical inspection system of the present invention.

2 and 3, the optical inspection system 100 includes a camera 110, illuminations 120, and a blocking member 130 for imaging the surface of the inspection object 10. The blocking member 130 and the lights 120 may be formed as one module.

The camera 110 is disposed to be spaced apart from an upper portion of the imaging area 10a of the inspection object 10. The blocking member 130 and the lights 120 are disposed at one side below the camera 110. Here, the camera 110 is for capturing an image of the imaging area 10a of the inspection object, and an image capturing device (CCD or CMOS) and an optical system (lens) may be used, and the image from the camera 110 may be used. The signal is provided to the image processing apparatus 180. The image processing apparatus 180 is provided as a typical computer system, and controls and processes various operations according to automatic optical inspection. The image processing apparatus 180 determines whether the surface of the inspection object is defective by using the image signal provided from the camera 110.

The blocking member 130 is perpendicular to the vertical light L1 reflected from the imaging area 10a and vertically incident to the camera 110 so as not to collide with the non-vertical light emitted from the lights 120. To protect L1). The blocking member 130 includes a support plate 132 on which the lights 120 are installed on the bottom, and a blocking plate 134 for dividing the outer area a and the vertical area b. b) can be installed symmetrically to each other on both sides or only one side. The lights 120 are preferably installed only on one support plate 132. The support plate 132 has a bottom 132a inclined downward, and the lights 120 are installed at different heights on the inclined bottom 132a to prevent light interference between the lights 120. For example, the lights 120 may be rotatably installed on the hinge portion of the bracket 133 to adjust the installation angle (irradiation angle) manually or automatically.

The outer area (a) is a space in which the lights 120 installed on the support plate 132 are located and at the same time the light of the lights 120 is provided to the imaging area 10a of the inspection object 10. The vertical area b may be a space in which only the vertical light L1 is incident to the camera 110 among the light reflected from the imaging area 10a.

The blocking plate 134 protects the vertical light L1 such that the vertical light L1 reflected from the imaging area 10a and incident vertically into the camera 10 does not collide with other non-vertical light L2. It has a basic function. In addition, the blocking plate 134 has a function of guiding the direction of the light so that the non-vertical light L2 irradiated from the lights 120 is irradiated to the imaging area 10a. To this end, the blocking plate 134 has an outer surface 135 made of a reflecting surface capable of reflecting light emitted from the lights 120 and providing its direction to the imaging area 10a. That is, the outer surface 135 guides non-vertical light, which is out of the imaging area 10a, from the light emitted from the lights 120 to be irradiated to the imaging area. The outer surface 135 is inclined to face the imaging area 10a, and the inclination angle X1 may be 75 ° or more and 90 ° (angle close to vertical) from the surface of the imaging area 10a.

As shown in FIG. 4, the blocking plate 134 is rotatably installed at the hinge portion 139 of the supporting plate 132 so that the inclination angle of the outer side 135 can be adjusted to the outer side 135. The direction of the reflected indirect light (L3) can be adjusted.

Meanwhile, in the present exemplary embodiment, the inner side surface 136 of the blocking plate 134 has the same inclination angle as the outer side surface 135, but as shown in FIG. 6, the blocking plate 134 has vertical light L1. It may have an inner side 136 ′ that is perpendicular to and parallel to it.

5 is a view showing an example provided with a rotatable blocking member as an optical inspection system according to an embodiment of the present invention. As shown in FIG. 5, the blocking member 130 may be rotated around the hinge shaft 138, and the installation angle of the lights 120 and the blocking plate 134 may be rotated through the rotation of the blocking member 130. The inclination angle of the outer surface 135 can be adjusted at the same time.

The outer surface 135 of the blocking plate 134 may be made of a material (stainless steel, etc.) that is coated (coated) with a light reflective gloss paint, adheres a reflective sheet, or has a good reflection. Optionally, the outer surface 135 may have an intaglio or embossed pattern so that light is reflected and provided to the imaging area 10a.

Referring again to FIGS. 2 and 3, the lights 120 illuminate four lights 122, 124a, and 124b that irradiate light into the imaging area 10a of the object 10 to be imaged by the camera 110. 124c). The lights 120 may be divided into one cast name 122 and three auxiliary lights 124a, 124b, and 124c. Casting name 122 and the three auxiliary lights (124a, 124b, 124c) are rotatably installed on the support plate 132 bottom surface 132a of the blocking member 130 to change the irradiation angle. In the present embodiment, the lights 122, 124a, 124b, and 124c use light emitting diodes (LEDs) having a light emitting angle (light spreading angle) of 20 ° -30 °, but other light sources such as lamps other than the light emitting diodes. This may be used. In addition, four lights were used in this embodiment, but this is only one embodiment.

Casting name 122 is illumination that directly irradiates light onto the surface of the imaging area 10a of the inspection object, casting name 122 is 75 ° or more and 90 degrees (angle close to vertical) from the surface of the imaging area 10a. It is installed to have a first installation angle (X2). Of course, the casting name 122 may also provide indirect light L3 that is irradiated to the outer surface 135 of the blocking plate and reflected indirectly to the imaging area 10a according to the installation angle. However, the amount of indirect light is relatively small compared to auxiliary lights. The first, second, and third auxiliary lights 124a, 124b, and 124c are larger than the cast name 122 so that the indirect light L3 is irradiated indirectly than the light directly irradiated to the surface of the imaging area 10a of the inspection object. It is installed to have a slope. As shown in FIG. 2, the installation angles of the casting name 122 and the first, second, and third auxiliary lights 124a, 124b, and 124c are set to the casting name (X2)> first auxiliary light (X3)> second auxiliary light. (X4)> Third auxiliary light (X5).

Looking at the light path of the lights in the optical inspection system 100 having the configuration as described above are as follows. First, the light emitted from the casting name 122 is irradiated to the imaging area 10a at an angle close to the vertical, and among the light reflected from the imaging area 10a, the vertical light L1 is a camera through the vertical area a. Incident at 110. At this time, if there are recessed portions (not shown) on the surface of the imaging area 10a, the portions irradiated with the recessed portions are dark because they are not reflected vertically. Therefore, when looking at the image picked up by the camera 110, since the indentations are dark, defect detection is very easy. Although some of the light emitted from the auxiliary lights 124a, 124b, and 124c is irradiated to the imaging area 10a, most of the light is irradiated to the outer surface 125 (reflection surface) of the blocking plate 124. The non-vertical light L2 irradiated to the outer surface 125 of the blocking plate 124 is guided along the outer surface 125 and indirectly provided to the imaging area 10a as an indirect light L3 close to the vertical. . In this case, the indirect light L3 that is irradiated and reflected on the outer surface 125 is provided as light that increases the amount of light in the imaging area 10a while being soft and uniform through the reflecting process. If the light irradiated from the auxiliary lights 124a, 124b, and 124c is directly irradiated onto the surface of the imaging area 10a, the part becomes bright due to light scattering inside the recesses of the surface, and thus the defective position is not visible. Problems may arise. do. Therefore, in the present invention, the irradiation angles (installation angles) of the auxiliary lights 124a, 124b, and 124c are inclined to prevent the undetection of such recessed portions, so that the light directly irradiated to the imaging area 10a is reduced as much as possible. In order to increase the amount of light incident on the camera 110, indirect light L3 is provided to the imaging area 10a.

The optical inspection system 100 according to the present invention can be very useful for inspecting a COF substrate in a film or tape type substrate. For example, a COF substrate has a very reflective surface whose surface is similar to a mirror. When the incident angle of light shining on the inspection object of the COF substrate is irradiated perpendicularly to the camera, the light is transmitted to the image sensor of the camera to obtain a clear image. That is, in the optical inspection system 100 of the present invention, the light L1 that is vertically reflected from the imaging area 10a of the inspection object 10 may be provided to the camera 110 without colliding with other light. The non-light L2 is irradiated by changing the direction of the non-vertical light L2 so as to provide indirect illumination close to the vertical in the imaging area 10a, thereby reducing the amount of light loss as much as possible and obtaining a clear image. It is.

The foregoing detailed description illustrates the present invention. In addition, the foregoing description merely shows and describes preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications, and environments. And, it is possible to change or modify within the scope of the concept of the invention disclosed in this specification, the scope equivalent to the written description, and / or the skill or knowledge in the art. The above-described embodiments are for explaining the best state in carrying out the present invention, the use of other inventions such as the present invention in other state known in the art, and the specific fields of application and uses of the present invention. Various changes are also possible. Accordingly, the detailed description of the invention is not intended to limit the invention to the disclosed embodiments. Also, the appended claims should be construed to include other embodiments.

As described above, the present invention can increase the reliability in inspecting the defective shape of the surface of the inspection object. The present invention not only can reduce the amount of light loss as much as possible, but also by adjusting the angle of the blocking member, it is possible to obtain a light component (a light component obtained by changing the angle) necessary for inspecting various defective shapes on the surface of the inspection object. . The present invention can be very usefully used to inspect a COF substrate in a film or tape type substrate.

Claims (17)

delete delete delete delete delete delete In an optical inspection system for optically inspecting the surface of an inspection object: A camera for imaging the surface of the inspection object; At least two lights for irradiating light to an imaging area of the inspection object to be picked up by the camera; And And a blocking member blocking the non-vertical light so that the vertical light reflected from the imaging area and incident vertically into the camera does not collide with the non-vertical light emitted from the at least two lights; The at least two lights A casting name installed to irradiate light on the surface of the imaging area of the inspection object at a first angle; And At least one auxiliary light is installed to irradiate light at an inclination angle smaller than the first angle of the casting name, The blocking member is positioned between the path through which the vertical light passes and the at least two illuminations so that non-vertical light that is out of the imaging area is irradiated to the imaging area among the light emitted from the at least one auxiliary light. And a blocking plate having an outer surface made of a reflective surface. In an optical inspection system for optically inspecting the surface of an inspection object: A camera for imaging the surface of the inspection object; At least two lights for irradiating light to an imaging area of the inspection object to be picked up by the camera; And And a blocking member blocking the non-vertical light so that the vertical light reflected from the imaging area and incident vertically into the camera does not collide with the non-vertical light emitted from the at least two lights; The at least two lights A casting name installed to irradiate light on the surface of the imaging area of the inspection object at a first angle; And At least one auxiliary light is installed to irradiate light at an inclination angle smaller than the first angle of the casting name, The blocking member is positioned between the path through which the vertical light passes and the at least two illuminations so that non-vertical light that is out of the imaging area is irradiated to the imaging area among the light emitted from the at least one auxiliary light. And a blocking plate which guides and has an outer side surface inclined toward the imaging area. In an optical inspection system for optically inspecting the surface of an inspection object: A camera for imaging the surface of the inspection object; At least two lights for irradiating light to an imaging area of the inspection object to be picked up by the camera; And And a blocking member blocking the non-vertical light so that the vertical light reflected from the imaging area and incident vertically into the camera does not collide with the non-vertical light emitted from the at least two lights; The at least two lights A casting name installed to irradiate light on the surface of the imaging area of the inspection object at a first angle; And At least one auxiliary light is installed to irradiate light at an inclination angle smaller than the first angle of the casting name, The blocking member is positioned between the path through which the vertical light passes and the at least two illuminations so that non-vertical light that is out of the imaging area is irradiated to the imaging area among the light emitted from the at least one auxiliary light. A blocking plate having a guided outer surface; And And a hinge part installed on the blocking plate so as to adjust an angle of light guided to the imaging area along an outer surface of the blocking plate. delete In an optical inspection system for optically inspecting the surface of an inspection object: A camera for imaging the surface of the inspection object; At least two lights for irradiating light to an imaging area of the inspection object to be picked up by the camera; And And a blocking member blocking the non-vertical light so that the vertical light reflected from the imaging area and incident vertically into the camera does not collide with the non-vertical light emitted from the at least two lights; The at least two lights A casting name installed to irradiate light on the surface of the imaging area of the inspection object at a first angle; And At least one auxiliary light is installed to irradiate light at an inclination angle smaller than the first angle of the casting name, The blocking member is positioned between the path through which the vertical light passes and the at least two illuminations so that non-vertical light that is out of the imaging area is irradiated to the imaging area among the light emitted from the at least one auxiliary light. A blocking plate having a guided outer surface; And An optical inspection system, the support plate being installed on the blocking plate, the casting name and the auxiliary lights installed on a bottom surface thereof, and a support plate rotatably installed to adjust an irradiation angle of the casting name and the auxiliary lights. . The method according to any one of claims 7 to 9, The cast name and the auxiliary lights are rotatably installed on the bottom surface of the blocking member. The method according to any one of claims 7 to 9, And an angle of inclination of the first angle of the casting name and the outer surface of the blocking plate is 75 ° to 90 ° with the surface of the imaging area. delete delete In an optical inspection system for optically inspecting the surface of an inspection object: A camera for imaging the surface of the inspection object; Illuminations for irradiating light to an imaging area of the inspection object to be imaged by the camera; And It includes a blocking member for providing a vertical area so that only the vertical light of the light that is irradiated to the imaging area of the inspection object is reflected to the camera; The blocking member includes an outer area where the lights are located and the light of the lights is provided to the imaging area of the inspection object, and a blocking plate for partitioning the vertical area. The blocking plate is formed of a reflecting surface, and the optical inspection system comprising an outer surface inclined so that the light irradiated to the outer surface of the blocking plate among the light irradiated from the illumination is guided to the imaging area. . The method of claim 16, The lights A casting name which is located closest to an imaging area of the inspection object and irradiates light to the imaging area at a first angle; And And auxiliary lights for illuminating the imaging area with an inclination angle smaller than the first angle of the casting name.

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