JP6042402B2 - Illumination module and visual inspection system using the same - Google Patents

Description

The present invention relates to an illumination module and an appearance inspection system using the illumination module, and more specifically, an illumination module that can uniformly irradiate light on the entire inspection surface of an inspection object and acquire an image, and an appearance inspection using the illumination module. About the system.

Normally, electronic components such as semiconductor chips and chip components are mounted on a printed circuit board using a chip mounter, and the board on which the electronic components are mounted is classified into good and defective products by testing the electrical characteristics. Are discarded and only good substrates are used.

Usually, a method of acquiring and inspecting an image of the appearance of an electronic component is mainly used to determine whether the electronic element is good or defective.

However, since the illumination module adopted in the conventional inspection system has directivity with respect to a specific area of the electronic component, there is a disadvantage that the entire surface of the electronic component cannot be irradiated with light uniformly.

Therefore, the occurrence of over-detection for determining a non-defective product as a defective product and the occurrence of non-detection for determining a defective product as a non-defective product are increasing.

Such an increase in undetected and overdetected causes a decrease in substrate productivity and an increase in cost. Therefore, an effective illumination module is required to be introduced into the inspection system.

Korean Patent Application Publication No. 2004-0089799

The objective of this invention is providing the illumination module which can irradiate light uniformly on the surface of the electronic component which is a test object, and an external appearance inspection system using the same.

An illumination module according to the present invention includes a housing having an inner surface formed in a dome shape, and is disposed inside the housing, and reflects light through the inner surface of the housing to indirectly inspect the inspection object. An illumination unit that emits light, and the illumination unit may include at least one light source having a wavelength in an ultraviolet region or an infrared region.

In this embodiment, the illuminating unit irradiates light toward the internal surface so that the maximum incident angle at which the light reflected by the internal surface is incident on the inspection object is 45 ° or more. Can do.

In the present embodiment, the housing is formed so that the inner surface is formed in a dome shape and reflects light emitted from the illumination portion, and protrudes inward from the lower end of the dome shape reflection portion. A light source arrangement unit.

In the present embodiment, the dome-shaped reflector may be formed in the shape of an integrating sphere.

In the present embodiment, the dome-shaped reflecting portion may be formed with a transmitting means capable of transmitting light at the uppermost end.

In the present embodiment, the camera module may further include a camera module that is disposed outside the dome-shaped reflection portion and photographs the inspection object through the transmission means.

In the present embodiment, the illumination unit may include at least one light source that irradiates light at a position adjacent to the transmission unit.

In the present embodiment, the dome-shaped reflector may have a smooth inner surface or a fine unevenness on the inner surface.

In the present embodiment, the light source arrangement unit may be formed with an inclined surface on which the illumination unit is arranged.

In the present embodiment, the light source placement unit may have an angle between 0 ° to 45 ° between the horizontal plane and the inclined surface.

In the present embodiment, the illumination unit can use at least one power LED as a light source.

In a present Example, the radius of the said dome shape reflection part should just be 20 mm-200 mm.

In this embodiment, the power LED can have a power of 350 to 370 mW.

The visual inspection system according to the present invention includes a housing having an inner surface formed in a dome shape, and is disposed inside the housing, and reflects light through the inner surface of the housing to the inspection object. An illumination unit that indirectly irradiates light; and a camera module that is disposed on the inspection object and that captures the appearance of the inspection object. The illumination unit includes an ultraviolet region or a visible region adjacent to the ultraviolet region. Light can be irradiated at a wavelength in the light ray region.

In the present embodiment, the illumination unit can irradiate light toward the inner surface of the housing so that the maximum incident angle of light incident on the inspection object is 45 ° or more.

The embodiment may further include a controller connected to the illumination module and the camera module to control functions of the illumination module and the camera module.

In addition, an appearance inspection system according to an embodiment of the present invention includes any one of the illumination modules described above, a camera module that captures an appearance of an inspection object irradiated with light by the illumination module, the illumination module, and the camera. And a controller connected to the module to control the functions of the illumination module and the camera module.

According to the present invention, the inspection object is indirectly irradiated with light using the illumination unit, and the inspection object is imaged using the camera module. Therefore, it is possible to obtain an accurate image that optically reduces the similar defects due to the surface state of the inspection target object and prevents undetected and overdetection.

The illumination module according to the present invention uses a light source in the ultraviolet region or infrared region. Therefore, it is possible to greatly improve the detection power for the shape defect of the outer boundary portion or the electrode dropout failure inside the electrode.

Further, since a large amount of light can be secured by using the power LED, there is an advantage that high-speed inspection can be realized.

It is a figure which shows the structure of the test | inspection system by the Example of this invention. 1 is a cross-sectional view schematically illustrating an illumination module according to an embodiment of the present invention. 1 is a cross-sectional view schematically illustrating an illumination module according to an embodiment of the present invention. 1 is a cross-sectional view schematically illustrating an illumination module according to an embodiment of the present invention. It is the comparison table | surface which showed both the image | video image | photographed using the conventional illumination module, and the image | video image | photographed using the illumination module by a present Example.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for a clearer description.

The illumination module according to the embodiment of the present invention may be an apparatus for inspecting the appearance of an electronic component. In addition, the electronic component according to the present embodiment includes, for example, an MLCC (Multi Layer Ceramic Capacitor) chip, a chip resistor, a varistor, a chip inductor, a chip array, and the like. Any micro-miniature semiconductor chip may be used. Further, the inspection object of the inspection apparatus of the present invention is the above-described damage (cracking), crack (crack) of the semiconductor chip, electrode exposure, spread of the external electrode, damage of the external electrode, no electrode, excessive electrode, short electrode. The electrode has been peeled off, miscut, defective in size, ruptured, defective in cutting, pinholes, foreign matter, external electrode bubbles, peeling of the electrode, discoloration of the external electrode, thickness defect or plating discoloration, etc. is there.

FIG. 1 is a diagram showing a configuration of an inspection system according to an embodiment of the present invention. Referring to FIG. 1, the inspection system according to the present embodiment may include an illumination module 1, a camera module 2, a transfer plate 4, and a controller 3.

The illumination module 1 can irradiate the electronic component with light for appearance imaging of the electronic component that is the inspection object P. In addition, the camera module 2 captures an image of the inspection object P irradiated with light by the illumination module 1. The illumination module 1 and the camera module 2 will be described later.

The transfer plate 4 is a plate having a circular shape, and can be rotated by driving means such as a motor. However, the present invention is not limited to this, and any material can be used in various forms as long as it can transfer the inspection object P to the inspection position, such as a conveyor. Further, the transfer plate 4 can be made of a transparent material such as glass so that the bottom surface of the inspection object P can be photographed.

The control unit 3 includes a computer or the like, and can be connected to the illumination module 1 and the camera module 2 to control their operations and functions.

The operation of the inspection system configured as described above will be briefly described as follows.

First, the inspection object P is arranged below the illumination module 1 by the transfer plate 4. Next, when the illumination module 1 uniformly irradiates the surface of the inspection object P, the camera module 2 captures the appearance of the inspection object P and transmits it to the control unit 3.

Therefore, the control unit 3 reads the photographed video and determines a non-defective product / defective product.

Below, the illumination module 1 by the Example of this invention is demonstrated.

2 to 4 are cross-sectional views schematically showing an illumination module according to an embodiment of the present invention, FIG. 3 is a cross-sectional view further showing an incident angle of the light source of FIG. 2, and FIG. It is sectional drawing for demonstrating arrangement | positioning.

2 to 4, the illumination module 1 according to the present embodiment includes a housing 100 and an illumination unit 130.

The housing 100 may include a dome-shaped reflection unit 110 and a light source arrangement unit 120.

The dome-shaped reflection unit 110 is formed in a dome shape, and includes a transmission unit 112 that can transmit light in the center. The transmission means 112 may be a medium that can transmit light or a hole through which light passes.

The inner surface of the dome-shaped reflector 110 has a characteristic that allows incident light to be reflected. The dome-shaped reflection unit 110 is formed in a half sphere shape so that light is uniformly incident and reflected, and specifically, may be formed in an integrating sphere shape. However, the present invention is not limited to this, and for example, it may be formed in an elliptical shape with a partially different curvature.

In addition, the illumination module 1 according to the present embodiment uses an indirect illumination method using the dome-shaped reflector 110 in order to uniformly irradiate light onto the surface of the electronic component that is the inspection object P. This will be briefly described as follows.

Usually, the surface of the inspection object P is formed with traces of friction and fine bends that are unrelated to the determination of good / bad. Such a portion acts as noise during the appearance inspection and becomes a factor of reducing the accuracy of the inspection.

In order to obtain uniform brightness over the entire surface regardless of the micro-bending surface or the trace of friction, a light source corresponding to the inclined angle of each surface that is differentiated from the bending surface must be provided.

For this reason, in this embodiment, an indirect irradiation method in which light is reflected and diffused by using a reflector called the dome-shaped reflector 110 is used instead of a method of directly irradiating the inspection object P with light.

Therefore, the inner surface of the dome-shaped reflection unit 110 can be formed of a material that can easily reflect light. Further, the reflection surface can be formed with a smooth surface. Further, if necessary, fine irregularities can be formed on the reflecting surface so that the reflected light can be reflected at various angles.

In addition, the dome-shaped reflector 110 according to the present embodiment may be formed in a hemispherical shape having a radius (r in FIG. 4) of 100 mm or more. This is derived from a size that can provide optimum efficiency corresponding to the case where the size of the inspection object P is 0.1 mm to 60 mm.

On the other hand, when the radius r of the dome-shaped reflecting portion 110 is 200 mm or more, there is a possibility that the distance between the light source 131 and the reflecting surface is increased and the light efficiency is lowered. Therefore, the dome-shaped reflector 110 according to the present embodiment is preferably formed in a hemispherical shape with a radius r in the range of 20 mm to 200 mm.

In the light source arrangement unit 120, a light source 131 of the illumination unit 130 described later is arranged. The light source arrangement part 120 can be formed so as to protrude from the lower end of the hemispherical dome-shaped reflecting part 110 to the center side (or inspection object side) of the hemisphere.

In addition, the light source placement unit 120 may be formed with an inclined surface on one surface on which the light source 131 is disposed, that is, an upper surface. This is a configuration for increasing the light efficiency of the illumination module 1 according to the present embodiment. This will be briefly described as follows.

When light enters the inspection object P, the smaller the incident angle θ ₁ , that is, the closer the light is incident vertically (or the normal direction of the inspection object), the higher the light efficiency.

When light vertically upward from the light source 131 is illuminated, the light emitted is to be irradiated very far spaced position from the highest point of the dome-shaped reflection portion 110, the incident angle theta ₁ is increased. In contrast, when light from the light source 131 at a position adjacent to the highest point of the dome-shaped reflection portion 110 is irradiated, the incident angle theta ₁ is reduced.

Therefore, the light source arrangement unit 120 according to the present embodiment is formed with an inclined surface so that the light emitted from the light source 131 is irradiated to the highest position of the hemisphere as much as possible (that is, the position adjacent to the transmitting means). Is done. Therefore, the upper surface of the light source arrangement part 120 can be formed as an inclined surface whose height (or thickness) decreases toward the inspection object P side.

Here, the angle θ ₂ between the inclined surface of the light source arrangement unit 120 and the horizontal plane may be in the range of 0 ° to 45 °. If the above angle theta ₂ is not less than 45 °, since the light is irradiated becomes farther travel of light off the center of the reflector, rather light efficiency increase effects may be reduced.

When a large number of light sources 131 are arranged along the inclined surface in this way, the light irradiated from the light sources 131 is reflected at a position adjacent to the transmission means of the dome-shaped reflection unit 110 and then is inspected at an angle close to vertical. Since the body P can be irradiated, the light efficiency can be maximized.

On the other hand, the light source arrangement unit 120 according to the present embodiment has a configuration derived corresponding to the case where the light source 131 emits light in the normal direction from the inclined surface of the light source arrangement unit 120. Therefore, when the light irradiation direction is not the normal direction, the shape of the light source arrangement unit 120 and the above angle may be changed.

The illumination unit 130 is arranged on the light source arrangement unit 120 and irradiates light toward the dome-shaped reflection unit 110. The light emitted from the illumination unit 130 is reflected by the inner surface of the dome-shaped reflection unit 110 and is applied to the inspection object P. That is, the light irradiated from the illumination unit 130 is indirectly irradiated to the inspection object P via the dome-shaped reflection unit 110.

The illumination unit 130 can include a plurality of light sources 131. In addition, each light source 131 can be arranged so as to be directed in the same direction, but is not limited thereto, and may be arranged so as to be directed in different directions as necessary.

Since the illumination unit 130 includes a plurality of light sources 131, light incident from the plurality of light sources 131 is diffusely reflected on the inner surface of the dome-shaped reflection unit 110. Accordingly, the inspection object P can be irradiated with light at various angles.

In the illumination unit 130 according to the present embodiment, an LED that is a light emitting diode can be used as the light source 131.

When an LED is used as the light source 131, LEDs of various hues can be used so that all the various defects of the electronic component that is the inspection object P can be detected.

For example, a blue LED, a green LED, and a white LED can be arranged to form a group. In this case, the blue LED is mainly used at the time of detecting defects such as cracks and chipping of the silver electrode part, and the green LED separates the main body part and the electrode part of the electronic component or the outline of the electronic component. Can be used mainly to get accurately.

The white LED can be mainly used when detecting a defect such as a crack in the main body. The above example is described by taking MLCC as an example, and the present invention is not limited to this, and may be variously changed according to the target of the electronic component.

That is, the light source 131 may be configured with only one hue LED depending on the shape and defect type of the electronic component, or may be configured such that two or more hue LEDs emit light simultaneously.

Further, the presence / absence of light emission and the light amount of the LED as the light source 131 can be variously set before the inspection depending on the shape, structure, hue, and the like of the electronic component to be inspected.

In addition, the illumination unit 130 according to the present embodiment may include at least one power LED having high luminance and high output.

When the indirect illumination method is used, the light efficiency is not as good as that of the direct illumination method, which causes a problem that the amount of light is insufficient. In particular, when a reflector is used, light is absorbed by the reflector itself, or light is emitted to other parts than the inspection object P, so that it is not easy to apply to a high-speed inspection method.

In order to solve such a problem, the illumination unit 130 according to the present embodiment can use, as the light source 131, a power LED (Power LED) that has a higher luminance and a higher light amount than a general high-brightness LED.

More specifically, a general high-intensity LED used conventionally has a power of 2.2 to 2.7 mW. However, the power LED used in this example can have a power of 350-370 mW. Therefore, a larger amount of light can be secured as compared with the conventional high brightness LED.

On the other hand, the illumination unit 130 according to the present embodiment can form all the light sources 131 with power LEDs. However, the present invention is not limited to this, and if necessary, only a part of the light source 131 may be selectively formed of power LEDs.

Further, the illumination unit 130 according to the present embodiment only needs to have the maximum incident angle θ ₁ of the reflected light of 45 ° or more when the light reflected by the reflecting surface is irradiated onto the inspection object P. Here, the incident angle θ ₁ means an angle formed by the normal line standing on the inspection object P and the traveling direction of the reflected light.

If the maximum incident angle theta ₁ is 45 ° or less, may light the entire surface of the inspection target object P light irradiated to the inspection target object P is focused mostly on the upper surface of the inspection target object P is not irradiated is there.

Thus, in this embodiment, the maximum incident angle theta ₁ of the light by a 45 ° or more, for irradiating light to the inspection object P in more various directions. Therefore, it is possible to effectively remove noise due to surface bending or the like in the captured image.

On the other hand, although the maximum incident angle theta ₁ can be a 90 ° or more, when the light source 131 is disposed along the inclined surface of the light source arrangement portion 120 as in this embodiment, structurally by mechanical arrangement because there is such a limit, a maximum incident angle theta ₁ preferably set to 90 ° or less. However, the configuration of the present invention is not limited to this.

In addition, the illumination unit 130 according to the present embodiment may include a light source 131 that emits ultraviolet rays or infrared rays.

More specifically, the light source 131 of the illumination unit 130 can emit light in the visible light region, and can also emit light in the ultraviolet region or infrared region.

In particular, the illumination unit 130 according to the present embodiment may include a light source 131 that emits a wavelength in the ultraviolet region or a wavelength in the visible light region adjacent to the ultraviolet region.

The wavelength band in the ultraviolet region or infrared region has a better refractive index and transmittance on the surface of the inspection object P than in the visible light region. Therefore, it is easier to detect defects on the surface of the inspection object P than in the visible light region.

The camera module 2 is installed outside the dome-shaped reflector 110 and images the inspection object P via the transmission means 112 of the dome-shaped reflector 110. Therefore, the camera module 2 is installed in a direction facing the inspection object P so that the inspection object P can be imaged. Specifically, the camera module 2 may be disposed in the normal direction of the inspection object P. it can.

Further, in this embodiment, the case where the camera module 2 is installed outside the dome-shaped reflection unit 110 is taken as an example, but various applications such as installation inside the dome-type reflection unit 110 are possible as necessary. Is possible.

In the illumination module 1 according to the present embodiment configured as described above, the light emitted from the illumination unit 130 enters the inner surface of the dome-shaped reflection unit 110. Thereafter, the light incident on the inner surface of the dome-shaped reflecting portion 110 is reflected corresponding to the curvature of the inner surface of the dome-shaped reflecting portion 110. Next, the reflected light is emitted in various directions and applied to the inspection object P, or is incident again on the inner surface of the dome-shaped reflection unit 110 and reflected, and then applied to the inspection object P. Is done.

That is, the illumination module 1 according to the present embodiment indirectly irradiates the inspection object P with the illumination unit 130 and images the inspection object P with the camera module 2. Therefore, it is possible to acquire an accurate image that optically reduces the similar defects due to the surface state of the inspection object P and prevents undetected and overdetection.

In addition, the illumination unit 130 according to the present embodiment includes a plurality of light sources 131. Therefore, since illumination is incident on the inspection object P at one angle at various angles, the light intensity of the entire surface of the inspection object P can be further increased.

Furthermore, the illumination module 1 according to the present embodiment uses a light source 131 in the ultraviolet region or the infrared region. Therefore, it is possible to greatly improve the detection power such as the shape defect of the outer boundary portion or the electrode dropout defect inside the electrode.

FIG. 5 is a comparison table showing both an image captured using a conventional illumination module and an image captured using an improved illumination module according to the present embodiment.

Here, an image using a conventional illumination module (existing illumination) is taken by a direct illumination method using a high-intensity LED having a wavelength in the visible light band as a light source. As described above, the image using the illumination module (improved illumination) according to the present embodiment is taken by the indirect illumination method using the power LED having the wavelength in the ultraviolet band as the light source.

Referring to FIG. 5, the image of the conventional illumination module is imaged in light and dark so that the electrodes are defective due to fine bending formed in the electrode portions. Therefore, it is difficult to clearly identify whether the product is defective or good by visual inspection.

On the other hand, in the image by the illumination module according to the present embodiment, similar defects on the electrode surface are optically reduced by indirect illumination. Therefore, there is no change in brightness due to fine bending, and a difference in brightness is clearly generated only in a portion where a defect is substantially generated. Therefore, the defective / non-defective product can be more easily classified as compared with the prior art.

The embodiment of the present invention has been described in detail above, but the scope of the present invention is not limited to this, and various modifications and variations can be made without departing from the technical idea of the present invention described in the claims. It will be apparent to those having ordinary knowledge in the art.

DESCRIPTION OF SYMBOLS 1 Illumination module 2 Camera module 3 Control part 100 Housing 110 Dome-type reflection part 120 Light source arrangement part 130 Illumination part

Claims (13)

A housing having an inner surface formed in a dome shape;
An illuminating unit that is disposed inside the housing and reflects light indirectly through the inner surface of the housing to indirectly irradiate the inspection object;
Including
The illumination unit includes at least one light source having a wavelength in the ultraviolet region,
The housing includes a dome-shaped reflection portion that reflects light emitted from the illumination portion, and a light source arrangement portion that is formed to protrude inward from a lower end of the dome-shaped reflection portion,
The light source arrangement portion, a surface that the illuminating part is arranged is formed in the inclined surface, an angle range of less than 0 ° exceed 45 ° between the horizontal plane and the inclined plane,
The inspection object is formed with a size of 0.1 mm to 60 mm,
The dome-shaped reflection unit is an illumination module having a radius of 20 mm to 200 mm. The illumination unit is
2. The illumination module according to claim 1, wherein light is emitted toward the inner surface so that a maximum incident angle at which the light reflected by the inner surface is incident on the inspection object is 45 ° or more. The dome-shaped reflector is
The illumination module according to claim 1, which is formed in the shape of an integrating sphere. The dome-shaped reflector is
The illumination module according to claim 1, wherein a transmission means capable of transmitting light is formed at an uppermost end.   The illumination module according to claim 4, further comprising a camera module that is disposed outside the dome-shaped reflection unit and photographs the inspection object through the transmission unit. The illumination unit is
The illumination module according to claim 4, comprising at least one light source that irradiates light at a position adjacent to the transmission means. The dome-shaped reflector is
The illumination module according to claim 1, wherein the inner surface is formed with a smooth surface or fine irregularities are formed on the inner surface. The illumination unit is
The illumination module according to claim 1, wherein at least one power LED is used as a light source. The power LED is
The lighting module according to claim 8, having a power of 350 to 370 mW. A housing having an inner surface formed in a dome shape, and an illuminating unit that is disposed inside the housing and reflects light indirectly through the inner surface of the housing to indirectly irradiate the inspection object. Including a lighting module;
A camera module that is arranged on the inspection object and photographs the appearance of the inspection object;
Including
The illumination module emits light at a wavelength in the ultraviolet region,
The housing includes a dome-shaped reflection portion that reflects light emitted from the illumination portion, and a light source arrangement portion that is formed to protrude inward from a lower end of the dome-shaped reflection portion,
The light source arrangement portion, a surface that the illuminating part is arranged is formed in the inclined surface, an angle range of less than 0 ° exceed 45 ° between the horizontal plane and the inclined plane,
The inspection object is formed with a size of 0.1 mm to 60 mm,
The dome-shaped reflection unit is an appearance inspection system having a radius of 20 mm to 200 mm. The illumination unit is
The appearance inspection system according to claim 10, wherein light is irradiated toward an inner surface of the housing so that a maximum incident angle of light incident on the inspection object is 45 ° or more.   The visual inspection system according to claim 10, further comprising a controller connected to the illumination module and the camera module to control functions of the illumination module and the camera module. At least one lighting module according to claim 1;
A camera module for photographing the appearance of the inspection object irradiated with light by the illumination module;
A controller connected to the illumination module and the camera module to control functions of the illumination module and the camera module;
Including visual inspection system.

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