JP2005321352A - Inspection apparatus and inspection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To change a background color tone by using a simple constitution when an inspected object is imaged. <P>SOLUTION: An inspection apparatus 100 has a CCD camera 102 for imaging the inspected object 120, a suction stage 110 for holding the inspected object 120, a first LED illumination 104 for irradiating the suction stage 110 with a first color light, a second LED illumination 108 for irradiating the suction stage 110 with a second color light different from the first color light on the opposite side to the first LED illumination, a second switch 114 for turning on or off an emission from the second LED illumination 108, and a transmission filter 106 for transmitting the second color light and absorbing the first color light. The transmission filter 106 is disposed between the suction stage 110 and the second LED illumination 108, and used for a background when the inspected object 120 is imaged by the CCD camera 102. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inspection apparatus and an inspection method for inspecting the appearance of an inspection object based on an image obtained by imaging the inspection object.

  When a foreign object inspection of a product is performed by image processing, it is necessary to obtain a sufficient contrast between the object and the background in order to perform the inspection with high accuracy. If contrast cannot be obtained, highly accurate inspection cannot be performed.

Patent Document 1 discloses an electronic component inspection apparatus in which when an electronic component is visually recognized by a reflected light image, the contrast between the electronic component and the background is increased by a relatively small change in illumination intensity. Here, the electronic component inspection apparatus has a configuration in which a background plate placed behind the electronic component is a photochromic glass. When the intensity of illumination is increased, the color tone of the photochromic glass shifts from a light color tone to a dark color tone. Therefore, the contrast between the electronic component and the background becomes larger than the change in illumination intensity.
Japanese Patent Laid-Open No. 7-151523

  In the conventional technique described above, the illuminance of illumination from the camera side has to be increased in order to change the color tone of the background. When the illuminance of the illumination on the camera side is increased, there is a problem that the inspection sensitivity decreases because the foreign object to be inspected becomes smaller on the image due to halation. Moreover, the subject that the contrast of a target object and a background cannot fully be obtained was still there.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique for changing the color tone of a background when imaging an inspection object with a simple configuration.

  According to the present invention, an inspection apparatus that inspects the appearance of an inspection object based on an image obtained by imaging the inspection object, a camera that images the inspection object, a holding unit that holds the inspection object, A first illumination that emits a first color toward the holding portion, and a second light that can emit a second color different from the first color toward the holding portion from the opposite side of the first illumination. A switch for turning on or off the light emission of the second illumination, and a transmission filter that transmits the second color and absorbs the first color, between the holding unit and the second illumination And a transmission filter serving as a background when the inspection object is imaged by the camera.

  With such a configuration, when the light emission of the second illumination is turned off, the first light emitted from the first illumination is absorbed by the transmission filter, and the inspection object is imaged by the camera by subtractive color mixture. The background is dark (black). Further, when the second illumination is turned on, the second light emitted from the second illumination is transmitted through the transmission filter, so that the first light emitted from the first illumination and the second light are emitted from the second illumination. Light is additively mixed and the background when the inspection object is imaged by the camera becomes a bright color (white). In this way, a black background and a white background can be realized simply by turning on or off the light emission of the second illumination, so the inspection sensitivity is good without changing the illumination intensity from the camera side. It is possible to perform an appearance inspection by changing the color tone of the background of the inspection object while keeping the state. As a result, the image of the inspection object can be acquired by changing the color tone of the background according to the difference in the color of the inspection object or the difference in adhesion of foreign matter.

  In the inspection apparatus of the present invention, the first color and the second color can be any one of the three primary colors of red, green, and blue. By using light of such a color, the effect of subtractive color mixing and additive color mixing can be enhanced and the color tone of the background can be greatly changed. Thereby, the precision of a test | inspection can be raised.

  The inspection apparatus of the present invention may further include a third illumination that emits a first color and a third color different from the second color toward the holding unit from the same side as the first illumination. . Thereby, the effect of subtractive color mixing and additive color mixing can be enhanced. Therefore, the color tone of the background can be greatly changed, and the accuracy of inspection can be further increased. In the inspection apparatus of the present invention, the third color can be any one of the three primary colors of red, green, and blue.

  According to the present invention, there is provided a method for inspecting the appearance of an inspection object using any one of the inspection apparatuses described above, wherein the step of holding the inspection object in a holding unit and turning off the light emission of the second illumination Capturing the first image with the camera, turning on the second illumination and capturing the second image with the camera, and at least one of the first image and the second image. And a step of inspecting the appearance of the inspection object using the inspection method.

  According to the present invention, as a background when imaging an inspection object, a backlight illumination that emits light of a predetermined color and can be switched on and off by a switch, and provided in front of the backlight illumination, The first image and the backlight illumination when the backlight illumination is turned off by irradiating the inspection object with light of a color different from the predetermined color using a filter that selectively transmits the prescribed color. An inspection comprising: a step of capturing a second image when turned on; and a step of inspecting the appearance of the inspection object using at least one of the first image and the second image. A method is provided.

  In this way, the background color of the inspection object can be changed between a bright color (white) and a dark color (black) simply by turning the backlight illumination on or off. It is possible to easily change the background color according to the difference or the difference in the foreign matter adhesion location. Thereby, the contrast between the inspection object and its background can be obtained, and the appearance inspection of the inspection object can be performed with high accuracy. In addition, the inspection range can be expanded.

  ADVANTAGE OF THE INVENTION According to this invention, the color tone of the background at the time of imaging a test object can be changed with a simple structure.

FIG. 1 is a diagram illustrating a configuration of an inspection apparatus 100 according to the present embodiment.
The inspection apparatus 100 includes a CCD camera 102, a first LED illumination 104 that emits a first color, a transmission filter 106, and a second LED illumination 108 that emits a second color different from the first color. And a suction stage 110 that holds the inspection object 120. The inspection apparatus 100 further includes a first switch 112 that turns on or off the light emission of the first LED illumination 104, a second switch 114 that turns on or off the light emission of the second LED illumination 108, and a first switch And a power supply 116 connected to the first LED illumination 104 and the second LED illumination 108 via the switch 112 and the second switch 114, respectively. Here, the transmission filter 106 selectively transmits the light of the second LED illumination 108.

  In the present embodiment, the CCD camera 102 images the inspection object 120 from above. The first LED illumination 104 illuminates the inspection object 120 obliquely from above. The second LED illumination 108 illuminates the inspection object 120 from below. The transmission filter 106 is provided between the suction stage 110 and the second LED illumination 108.

  The light from the first LED illumination 104 passes through the inspection object 120 and then irradiates the transmission filter 106. The light from the second LED illumination 108 passes through the transmission filter 106 and is applied to the inspection object 120. When the inspection object 120 is imaged by the CCD camera 102, the background of the inspection object 120 is configured by the transmission filter 106 and the second LED illumination 108. The inspection object 120 is a semiconductor device such as an IC package.

  In the present embodiment, the first LED illumination 104 is red LED illumination. The second LED illumination 108 is a blue LED illumination. The transmission filter 106 is a blue transmission filter that selectively transmits blue light (wavelength 450 nm).

Next, the operation of the inspection apparatus 100 configured as described above will be described with reference to FIGS. 1 and 2.
First, as shown in FIG. 1A, the first switch 112 is turned on and the second switch 114 is turned off. At this time, the first LED illumination 104 emits light, and the second LED illumination 108 does not emit light. In this state, the inspection object 120 is imaged by the CCD camera 102. Since the transmission filter 106 absorbs red light (wavelength 650 nm) emitted from the first LED illumination 104, there is no reflection of light from the transmission filter 106, and an image of the inspection object 120 captured by the CCD camera 102 is captured. The background 130 becomes black (FIG. 2A).

  Subsequently, as shown in FIG. 1B, the second switch 114 is also turned on while the first switch 112 is kept on. Thereby, the second LED illumination 108 also emits light. In this state, the inspection object 120 is imaged by the CCD camera 102. Since the transmission filter 106 transmits the blue light emitted from the second LED illumination 108, red light and blue light are additively mixed in the background of the inspection object 120, and the CCD camera 102 moves the inspection object 120. The background 132 of the captured image is white (FIG. 2B).

  The appearance inspection of the inspection object 120 can be performed using the two images having the black background and the white background obtained as described above. Further, the appearance inspection of the inspection object 120 can be performed using one image having a large contrast with the inspection object 120.

  As described above, according to the inspection apparatus 100 in the present embodiment, a black background and a white background can be realized only by turning on and off the second LED illumination 108 that is the background of the inspection object 120. Can do. In this way, since the color tone of the background can be changed without changing the illuminance of the first LED illumination 104 above the inspection object 120, the inspection object 120 can be inspected with good inspection sensitivity. It can be performed.

FIG. 3 is a diagram illustrating another example of the inspection apparatus 100 according to the present embodiment.
In addition to the configuration shown in FIG. 1, the inspection apparatus 100 further includes a third LED illumination 118 that emits a third color that is different from the first color and the second color, and the light emission of the third LED illumination 118. And a third switch 119 for turning on or off. Here, the third LED illumination 118 may be a green LED illumination. The first LED illumination 104, the transmission filter 106, and the second LED illumination 108 are the same as described with reference to FIG.

With reference to FIG. 2 and FIG. 3, operation | movement of the test | inspection apparatus 100 of such a structure is demonstrated.
First, the first switch 112 and the third switch 119 are turned on, and the second switch 114 is turned off. At this time, the first LED illumination 104 and the third LED illumination 118 emit light, and the second LED illumination 108 does not emit light. In this state, the inspection object 120 is imaged by the CCD camera 102. The transmission filter 106 absorbs the light emitted from the first LED illumination 104 and the third LED illumination 118, so that there is no reflection of light from the transmission filter 106. Therefore, the image obtained by imaging the inspection object 120 with the CCD camera 102 has a black background 130 as shown in FIG. Here, both the first switch 112 and the third switch 119 are turned on, but only one of them may be turned on.

  Subsequently, the first switch 112, the third switch 119, and the second switch 114 are all turned on. Thereby, the second LED illumination 108 also emits light. In this state, the inspection object 120 is imaged by the CCD camera 102. Since the transmission filter 106 transmits the blue light emitted from the second LED illumination 108, red light, green light, and blue light are additively mixed in the background of the inspection object 120. As a result, the image obtained by imaging the inspection object 120 with the CCD camera 102 has a white background 132 as shown in FIG.

  In this way, by providing the first LED illumination 104 and the third LED illumination 118 above the inspection target 120, the first LED illumination 104, the second LED illumination 108, and the third LED illumination. When all of 118 are made to emit light, the background of the inspection object 120 can be made clearer white, and an accurate inspection result can be obtained.

  The present invention has been described based on the embodiments and examples. It is to be understood by those skilled in the art that the embodiments and examples are merely examples, and various modifications are possible and that such modifications are within the scope of the present invention.

  In the above embodiment, the case where the second LED illumination 108 is blue LED illumination and the transmission filter 106 is a blue transmission filter has been described as an example. However, the second LED illumination 108 and the transmission filter 106 are, for example, A combination of a red LED illumination and a red transmission filter, or a green LED illumination and a green transmission filter may be used. In this case, as the first LED illumination 104 or the third LED illumination 118, LED illumination of a color different from that of the second LED illumination 108 is used.

  Moreover, in the above embodiment, red, blue, and green were shown as an example of LED illumination, but it can also be made into the thing of colors other than this.

  In the above embodiment, the case where the inspection target 120 is an IC package has been described as an example. However, the inspection target 120 is not limited to a semiconductor device such as an IC package, and may be any type. .

It is a figure which shows the structure of the test | inspection apparatus in embodiment of this invention. It is a figure which shows the image imaged with the test | inspection apparatus in embodiment of this invention. It is a figure which shows the other example of a structure of the test | inspection apparatus in embodiment of this invention.

Explanation of symbols

100 inspection device 102 CCD camera 104 first LED illumination 106 transmission filter 108 second LED illumination 110 suction stage 112 first switch 114 second switch 116 power supply 118 third LED illumination 119 third switch 120 inspection object Stuff

Claims (6)

An inspection apparatus that inspects the appearance of the inspection object based on an image obtained by imaging the inspection object,
A camera for imaging the inspection object;
A holding unit for holding the inspection object;
A first illumination that emits a first color toward the holder;
A second illumination capable of emitting a second color different from the first color from the opposite side of the first illumination toward the holding unit;
A switch for turning on or off the emission of the second illumination;
A transmission filter that transmits the second color and absorbs the first color, is disposed between the holding unit and the second illumination, and images the inspection object with the camera And a background transmission filter,
The inspection apparatus characterized by including. The inspection apparatus according to claim 1,
The inspection apparatus according to claim 1, wherein the first color and the second color are any one of three primary colors of red, green, and blue. The inspection apparatus according to claim 1 or 2,
The inspection further includes a third illumination that emits a third color different from the first color and the second color from the same side as the first illumination toward the holding unit. apparatus. The inspection apparatus according to claim 3, wherein
The inspection apparatus according to claim 3, wherein the third color is one of three primary colors of red, green, and blue. A method for inspecting the appearance of the inspection object using the inspection apparatus according to claim 1,
Holding the inspection object in the holding unit;
Imaging the first image with the camera with the second illumination turned off;
Turning on the second illumination and taking a second image with the camera;
Inspecting the appearance of the inspection object using at least one of the first image and the second image;
The inspection method characterized by including. Backlight illumination that emits light of a predetermined color and can be switched on and off by a switch as a background when imaging an inspection object, and is provided in front of the backlight illumination and selects the predetermined color The first image and the backlight illumination when the backlight illumination is turned off by irradiating the inspection object with light of a color different from the predetermined color. A step of taking a second image when
Inspecting the appearance of the inspection object using at least one of the first image and the second image;
The inspection method characterized by including.

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