JP5424660B2 - Inspection device for inspection object - Google Patents

Description

  The present invention relates to an inspection apparatus for an object to be inspected, and more particularly to an inspection apparatus for an object to be inspected in which at least a part of the surface is coated with a coating.

  According to Patent Document 1, transparent ink is applied to form a transparent resin layer on the object surface to protect the object surface, or a white ink underlayer is formed on the object surface before applying colored ink. Conventionally, the biting and coloring of colored inks are improved. Patent Document 1 describes that a phosphor is mixed in advance with a transparent or white ink, and the thickness of the layer is measured from the fluorescence emitted from the ink layer that has received ultraviolet rays.

Japanese Patent Laid-Open No. 10-46071

  For example, the surface may be coated with a resin or the like in order to improve the waterproofness and moistureproofness of an object to be inspected such as an electronic substrate or to reduce deterioration with time. In order to enhance the visibility of the substrate surface after coating, a colorless coating agent is often used. The coating can be inspected by irradiating the coating agent with a fluorescent agent and irradiating it with ultraviolet light after application. For example, the thickness of the coating is inspected.

  However, particularly in the case of coating on an electronic substrate, the coating may not only be applied to the entire surface but also to a specific part of the surface. For example, the coating may be performed only on the part, or conversely, the coating may be performed while avoiding the part. In this case, for example, it is desirable to be able to accurately inspect the coating application position. Further, it is desirable that foreign matter inside or on the surface of the coating layer can be accurately inspected.

  In reality, these coating inspections are performed manually by visual inspection of inspectors.

  This invention is made | formed in view of such a condition, The objective is to provide the inspection apparatus which can test | inspect the coating of a to-be-inspected object.

  An inspection apparatus according to an aspect of the present invention is an inspection apparatus for an inspection object in which at least a part of the surface is coated with a coating that emits fluorescence when receiving ultraviolet light, and includes an ultraviolet light source and an inspection object that receives ultraviolet light. An imaging unit that receives fluorescence from the body and generates a plurality of images each separated into different color components, and inspects the coating of the inspected object based on at least one of the images generated by the imaging unit An inspection unit.

  According to this aspect, the coating inspection can be automatically performed. In addition, a plurality of images are generated by color-separating fluorescence generated by irradiating the inspection object with ultraviolet light. By selecting and inspecting any one or a plurality of images from a plurality of images, the coating inspection can be performed with high accuracy.

  The inspection unit may select and inspect one of a plurality of color-separated images for each inspection area. The inspection unit may determine the type of coating applied to the inspection area based on the image of the selected color component. The inspection unit may inspect the foreign matter by selecting an image according to the foreign matter to be inspected from a plurality of color-separated images. The inspection unit may select and inspect an image according to an inspection item from a plurality of images having different dynamic ranges obtained by the imaging unit.

  According to the present invention, it is possible to inspect the coating of an object to be inspected.

It is a figure showing typically composition of a coating inspection device concerning one embodiment of the present invention. It is a detailed perspective view of the test unit of FIG. It is a schematic diagram of the test unit containing the illumination unit of FIG. It is a figure which shows the structure of the line sensor which concerns on one Embodiment of this invention. It is a figure which shows an example of a structure of the analysis unit which concerns on one Embodiment of this invention. It is a flowchart which shows the test | inspection procedure of the coating test | inspection apparatus which concerns on one Embodiment of this invention. It is a flowchart which shows the coating test | inspection process which concerns on one Embodiment of this invention.

  In one embodiment of the present invention, a coating inspection apparatus inspects a coating of an inspection object based on an illumination light source that illuminates the inspection object, a sensor that receives light from the illuminated inspection object, and a sensor output. A main control unit. The coating inspection apparatus may include an optical system that guides light from the object to be inspected to the sensor, and a moving mechanism that relatively moves the sensor and the object to be inspected.

  The object to be inspected may be coated on at least a part of its surface with a coating that emits fluorescence upon receiving ultraviolet light. The coating agent may contain a fluorescent agent that emits fluorescence in the visible light region upon receiving ultraviolet light. The illumination light source may include an ultraviolet light source that emits ultraviolet light and a visible light source that emits visible light. The sensor may be a light receiving device that receives fluorescence emitted when the inspection object is illuminated with ultraviolet light and reflected light when the inspection object is illuminated with visible light. The light receiving device receives the fluorescence from the object to be inspected that has received ultraviolet light, generates an ultraviolet light image, and receives the reflected light from the object to be inspected that has received visible light to generate a visible light image. It may be. The imaging device may output an ultraviolet light image and a visible light image to the main control unit.

  The main control unit may include an inspection unit that inspects the coating of the object to be inspected based on the image to be inspected, and a position specifying unit that specifies position information of the object to be inspected in the image to be inspected. The position specifying unit may specify the position of the reference mark formed in advance on the object to be inspected based on the visible light image. The main control unit may include a position correction unit that corrects the position of the inspection image based on the reference mark position. The position correction unit may correct the position of the inspection image based on the reference mark position specified by the position specifying unit. Alternatively, either one of the position specifying unit and the position correcting unit may be configured to perform both the specification of the reference mark position and the inspection image correction based on the reference mark position. The inspection unit may set an inspection range in the image to be inspected based on the reference mark position, and determine the quality of the coating by comparing the inspection range with the reference image. When the coating region is a part on the substrate, a part of the image to be inspected may be set as the inspection range, and only the inspection range may be inspected.

  In an ultraviolet image, it may be difficult to recognize the reference mark on the coating base surface due to the fluorescence emitted by the coating. According to an embodiment of the present invention, since the position on the surface of the object to be inspected can be accurately identified from the visible light image, the coating position is not only inspected for the presence or absence of coating thickness unevenness or omission. Can be inspected with sufficient accuracy.

  The ultraviolet light source may be a light source that emits light including ultraviolet light instead of emitting only ultraviolet light. Alternatively, the ultraviolet light source may be a light source that emits ultraviolet light having a specific wavelength selected from the ultraviolet light region or a wavelength region. Similarly, the visible light source may be a light source that emits light including visible light instead of emitting only visible light. The visible light source may be a light source that emits light of a specific wavelength or wavelength range selected from the visible light range.

  The fluorescence emitted by the coating desirably includes light in the visible light range. If it does so, the imaging device for visible light can be shared. In this case, the captured image is actually an image illuminated with visible light fluorescence. However, in order to distinguish it clearly from the case of pointing an image when illuminated with a visible light source, it will be referred to as an “ultraviolet light image” for the sake of convenience. An image when illuminated with a visible light source is referred to as a “visible light image”.

  Moreover, in one Embodiment of this invention, the illumination unit containing the 1st illumination light source which radiates | emits 1st illumination light, and the 2nd illumination light source which radiates | emits the 2nd illumination light which has a spectrum different from 1st illumination light. May be provided. The first illumination light may include light having a wavelength that generates fluorescence in the coating of the object to be inspected, and the second illumination light may include light having a wavelength that passes through the coating and is reflected by the coating base surface. The main control unit may include an image processing unit that associates the first image obtained when illuminated with the first illumination light and the second image obtained when illuminated with the second illumination light. The image processing unit may generate a correspondence relationship of each pixel between the first image and the second image. For example, the image processing unit may acquire the relationship between the position of the inspection object in the second image and the position in the first image corresponding to the position. If it does in this way, the application state of coating can be test | inspected from a 1st image, and the position on a to-be-coated surface can be pinpointed from a 2nd image. Therefore, it is possible to precisely inspect the application state at a specific position on the surface of the object to be inspected.

  An inspection apparatus according to an embodiment of the present invention is an inspection apparatus for an inspected object in which at least a part of a surface is coated with a coating that emits fluorescence when receiving ultraviolet light, and includes an ultraviolet light source, a visible light source, and an ultraviolet light. An imaging unit that receives fluorescence from an object to be inspected that receives light, generates an ultraviolet light image, receives reflected light from the object to be inspected that receives visible light, and generates a visible light image; and a visible light image Based on the position specifying unit for specifying the position information of the object to be inspected, the position information of the object to be inspected specified by the position specifying unit, and at least the ultraviolet light image among the images generated by the imaging unit And an inspection unit that inspects the coating of the object to be inspected.

  An inspection apparatus according to an embodiment of the present invention is an inspection apparatus for an inspected object in which at least a part of a surface is coated with a coating that emits fluorescence when receiving ultraviolet light, and includes an ultraviolet light source, a visible light source, and an ultraviolet light. An imaging unit that receives fluorescence from an object to be inspected that receives light to generate an ultraviolet light image, receives reflected light from the object to be inspected that receives visible light, and generates a visible light image; and an ultraviolet light image And an inspection unit that inspects the coating of the object to be inspected based on an image in which a difference in luminance between corresponding pixels of each visible light image is set to the luminance of each pixel.

  In one embodiment of the present invention, the coating inspection apparatus may use a processed image obtained by subtracting a visible light image from an ultraviolet light image as an inspection image. The coating inspection apparatus may include an inspection unit that inspects the coating of the object to be inspected based on a processed image in which the luminance difference between the corresponding pixels of the ultraviolet light image and the visible light image is set to the luminance of each pixel. The inspection unit may inspect at least one of coating omission and thin coating of the object to be inspected based on the processed image.

  The ultraviolet light image includes fluorescence of the coating that has received ultraviolet light from an ultraviolet light source, and reflected light on the surface of the object to be inspected that has received the fluorescence of the coating as visible light. The visible light image includes reflected light on the surface of the object to be inspected that has received visible light from a visible light source. Inspecting coating omission and thin coating is based on whether or not the amount of fluorescent light emitted by the coating is smaller than the amount of light used as a criterion. It becomes noise. In the processed image described above, the reflected fluorescent light of the ultraviolet light image that becomes noise is canceled out by the reflected light of the visible light image. Therefore, it is possible to extract only the fluorescent component of the coating necessary for the coating omission inspection and the thin coating inspection from the ultraviolet light image and perform the inspection with high accuracy.

  In this case, the coating inspection apparatus may include a visible light source that emits visible light having substantially the same spectrum as the fluorescence emitted by the coating that has received ultraviolet light. The coating inspection apparatus may include a visible light source that emits visible light having substantially the same spectral reflectance as the fluorescence emitted by the coating that has received ultraviolet light.

  Or an inspection part is good also considering the image obtained as a difference of the image of the same color component among the images obtained by color-separating each of an ultraviolet light image and a visible light image as a to-be-inspected image. The inspection unit may select a color component having the strongest fluorescence intensity of the coating. For example, when the fluorescence is bluish light, a blue component may be extracted from the ultraviolet light image and the visible light image to take a difference.

  In one embodiment of the present invention, a coating inspection device receives fluorescence from an illumination unit including at least an ultraviolet light source that emits ultraviolet light and an object to be inspected that has received ultraviolet light, and each has a different color component. An imaging device that generates a plurality of decomposed images, and an inspection that inspects the coating of an object to be inspected by selecting one of a plurality of images having different color components and comparing the image of the selected color component with a reference May be provided.

  In place of so-called color separation, the coating may be inspected using an image captured at a specific wavelength or wavelength range. The coating inspection apparatus includes an illumination unit including at least an ultraviolet light source that emits ultraviolet light, an imaging apparatus that generates light by receiving light of a predetermined wavelength or wavelength range from an inspection object that has received ultraviolet light, and a generation An inspection unit that inspects the coating of the object to be inspected based on the image that has been obtained.

  The inspection unit may select and inspect one of a plurality of color-separated images for each inspection area, or may inspect by combining a plurality of color-separated images. In this case, the inspection area is an area defined on the image to be inspected, and may be, for example, a single pixel or an area composed of a plurality of pixels. Specifically, the image to be inspected may be divided into a plurality of inspection areas according to, for example, the type of coating agent. For example, when different coating agents are applied to the electronic component and the substrate surface, the electronic component region and the substrate surface region may be divided into different inspection areas. Also, the inspection area may be set according to the characteristics of the base of the coating (for example, material and color). For example, the area where the base is the electronic component and the area where the base is the substrate surface are divided into different inspection areas. May be.

  The inspection unit may determine the correctness of the coating applied to the inspection area or the type of coating agent based on the image of the selected color component. The coating agent can be easily identified by utilizing the fact that the wavelength peak of the fluorescence spectrum varies depending on the coating agent. The inspection unit may select and inspect one of a plurality of color-separated images according to the characteristics of the coating base in the inspection area. An image to be inspected that can expect a more accurate inspection result may be selected for each inspection area.

  The inspection unit selects the first image generated by the first wavelength range and performs the first inspection, and also generates the second image generated by the second wavelength range different from the first wavelength range. A second inspection different from the first inspection may be selected. The first inspection may be, for example, a rough inspection that detects coating omission or thin coating from the entire surface of the substrate, and the second inspection is a detailed inspection that detects, for example, fine foreign matters in the coating. Also good. Further, the first and second inspections may inspect different types of foreign matters.

  The inspection unit selects the first image having the first dynamic range to perform the first inspection, and selects the second image having the second dynamic range different from the first dynamic range. Then, the second inspection may be performed. In this case, the difference in the dynamic range between the two images is caused by, for example, a difference in brightness due to a difference in color components of the images. Further, the dynamic range may be different depending on the difference in the amount of fluorescence received by ultraviolet light irradiation. The amount of received fluorescence can be controlled by adjusting, for example, the intensity of light emitted from the ultraviolet light source or the imaging time of the imaging device. The first image and the second image may be images captured by irradiating illumination light having different wavelength ranges, or may be images captured with illumination light having a common wavelength range. .

  For example, the inspection unit may perform a first inspection by selecting a bright image among a plurality of images obtained by color separation, and may perform a second inspection by selecting a dark image among the plurality of images. . The inspection unit may perform the first inspection by selecting the brightest image and may perform the second inspection by selecting the darkest image. The inspection unit may select a blue component image as a bright image and a green component image as a dark image. The image to be inspected in the first inspection may be, for example, an image whose image brightness exceeds a predetermined reference value, and the image to be inspected in the second inspection may be, for example, an image whose image brightness does not satisfy the predetermined reference value. . The brightness of the image may be, for example, the average luminance of all the pixels of the image, and the reference value can be appropriately determined experimentally or empirically.

  The inspection unit may inspect the foreign matter by selecting an image from the plurality of color-separated images according to the foreign matter to be inspected. The foreign object to be inspected may be, for example, any of bubbles contained in the coating layer, dust such as substrate residue, brush hair used for applying the coating agent, and scratches on the surface. A highly accurate inspection can be realized by generating or selecting an optimal image according to the inspection object.

  Scattered light generated by a foreign substance has a strong blue component with a short wavelength and a weak green component with a long wavelength due to Rayleigh scattering. Therefore, the outline of a foreign substance (for example, a bubble) tends to appear thick in a blue component image and thin in a green component image. Therefore, the inspection unit may select different color components (or wavelength ranges) according to the required inspection accuracy. For example, a blue component image may be selected when high inspection accuracy is required.

  An inspection apparatus according to an embodiment of the present invention is an inspection apparatus for an inspection object in which at least a part of a surface is coated with a coating that emits fluorescence when receiving ultraviolet light, and receives an ultraviolet light source and ultraviolet light. An imaging unit that receives fluorescence from the object to be inspected to generate an ultraviolet light image, and a shading correction unit that performs shading correction of the ultraviolet light image based on the intensity of the fluorescence emitted by the reference member that has received the ultraviolet light. May be.

  In one embodiment of the present invention, the coating inspection apparatus may include a reference member that emits fluorescence upon receiving ultraviolet light. The main control unit may include a shading correction unit that performs shading correction based on the intensity of fluorescence from the reference member. By calibrating the brightness, variations in inspection results can be suppressed. In particular, since it is assumed that the ultraviolet light source has larger deterioration and variation with time than the visible light source, it is preferable to calibrate the ultraviolet light in order to realize a coating inspection apparatus having excellent practicality.

  The shading correction unit may measure the fluorescence emitted from the reference member and calibrate the luminance for each of the plurality of color components. The shading correction unit may perform shading correction of the visible light image based on the intensity of reflected light from the reference member that has received visible light. The reference member may be a region where the region receiving ultraviolet light and the region receiving visible light are common. In this case, the reference member may be a white plate containing a fluorescent brightener. In this way, calibration for ultraviolet light and visible light can be performed using a common reference member.

  The reference member may be divided into an ultraviolet light correction region that emits fluorescence upon receiving ultraviolet light and a visible light correction region that reflects visible light. Further, a reference member for ultraviolet light and a reference member for visible light may be provided separately. The ultraviolet light correction region or the ultraviolet light reference member may be, for example, a plate containing a fluorescent brightening agent. The visible light correction region or the visible light reference member may be, for example, a white plate.

  FIG. 1 schematically shows a configuration of a coating inspection apparatus 10 according to an embodiment of the present invention. In this apparatus, an inspection surface of an object to be inspected is scanned with a line sensor to form an image, and whether the coating application state is acceptable or not is determined by image recognition. By driving the scanning head perpendicular to the imaging line by the line sensor, an image for each line is sequentially obtained, and the inspection is completed by one-dimensional movement of the scanning head.

  As shown in FIG. 1, the coating inspection apparatus 10 includes a main unit 12 and a test unit 14. A support base 22 is provided below the test unit 14 to hold the substrate 1 as an object to be inspected. The support 22 is provided with a conveyor so that, for example, the substrate 1 that is the object to be inspected is gripped and flows from another process at a constant speed. Above the test unit 14, a scanning head 16, a stepping motor 20 that drives the scanning head 16, and a guide 18 such as a linear guide that supports the scanning head 16 are provided.

  The scanning head 16 has an illumination unit 30, a lens 32, and a line sensor 34. These members are fixed on the frame 36. The illumination unit 30 includes a side illumination source, a total reflection mirror, and the like which will be described later. Side illumination sources include ultraviolet light sources and visible light sources. Reflected light vertically upward from the substrate 1 is guided to the lens 32 by a mirror, and after passing through the lens 32, is input to the line sensor 34 which is a one-dimensional CCD sensor. The line sensor 34 images the substrate 1 line by line and outputs the image data 54.

  The test unit 14 is provided with a reference plate 60 for shading correction at a position facing the scanning head 16 at a standby position in a standby state before inspection. The reference plate 60 is connected to a position adjustment mechanism (not shown) that adjusts the position of the reference plate 60. The reference plate 60 is a resin-made white plate-like member containing a fluorescent brightening agent. Instead of the reference plate 60, a resin white sheet containing a fluorescent brightening agent may be used.

  The main unit 12 controls the entire apparatus as a whole, and can be realized in hardware by a CPU, memory, or other LSI of any computer, and in software, a coating inspection loaded in the memory. It is realized by a functional program or the like, but here, functional blocks realized by their cooperation are depicted. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

  First, the head control unit 40 of the main unit 12 supplies an illumination control clock 50 (hereinafter also referred to as a synchronization signal) to the illumination unit 30, and alternately switches on and turns off ultraviolet light illumination and visible light illumination for each line. . The head control unit 40 further outputs a motor control signal 52 to the motor 20 and a test start signal 56 to the memory control unit 42, respectively. The motor 20 is step-controlled by the motor control signal 52, and the scanning head 16 moves to the end of the substrate 1 at the start of inspection. Hereinafter, this position is referred to as a “start position”. Thereafter, every time one line is imaged, the scanning head 16 advances by one line by the motor control signal 52. On the other hand, referring to the test start signal 56, the memory control unit 42 controls the writing of the image data 54 to the memory 44, and thereafter, the image data 54 is recorded in line units. When the image data 54 is selectively input line by line, one captured when illuminated with ultraviolet light and one captured when illuminated with visible light, and all lines have been imaged. In the memory 44, an ultraviolet light image captured when illuminated with ultraviolet light and a visible light image captured when illuminated with visible light are formed.

  For example, the main unit 12 performs shading correction in a standby state. In the standby state, the inspection apparatus 10 is not provided with the substrate 1. When performing shading correction, the head control unit 40 of the main unit 12 controls the motor 20 by the motor control signal 52 to maintain the scanning head 16 at the standby position. The head control unit 40 outputs an illumination control signal 50 to the illumination unit 30 and controls the lighting state for shading correction.

  The main unit 12 generates a shading correction value so that the fluorescence brightness obtained when the reference plate 60 is illuminated with an ultraviolet light source becomes a preset reference brightness. In addition, the main unit 12 generates a shading correction value so that the brightness of the reflected light obtained when the reference plate 60 is illuminated with a visible light source becomes a preset reference brightness. Shading correction is performed for each of the RGB color components of the line sensor 34.

  Note that the internal configuration of the memory 44 and the arrangement of the image data 54 in the memory 44 have a degree of freedom in design, and various configurations are possible. For example, two independent storage areas for individually storing the ultraviolet light image and the visible light image are provided in the memory 44, and the memory control unit 42 divides the image data 54 into each storage area for each line. May be controlled to be stored separately. Alternatively, a single storage area for storing an ultraviolet light image and a visible light image is provided in the memory 44, and the memory control unit 42 has the image data 54 alternately line by line in the single storage area. You may control so that it may be stored in.

  The analysis unit 46 reads the image data from the memory 44 in parallel with the scan or after the scan is completed, takes into account the shading correction value obtained previously, and in light of the determination criterion recorded in the determination criterion storage unit 48 in advance. Judge pass / fail for each inspection item. The inspection items include, for example, coating omission, thin coating, bubbles, and dust. The analysis unit 46 determines the presence / absence of each inspection item. The analysis unit 46 may further specify a position on the substrate for each inspection item. In the judgment reference storage unit 48, judgment criteria or reference images relating to pass / fail are recorded in advance regarding the coating application state of the substrate 1 to be inspected, and these standards or images are applied to the images actually acquired by the line sensor 34. A pass / fail decision is made.

  FIG. 2 is a perspective view of the test unit 14, and FIG. 3 is a schematic view of the test unit 14 as viewed from an imaging line direction 110 of the line sensor 34 (hereinafter simply referred to as an imaging direction). When the image data for one line is captured in the state shown in FIG. 2 or FIG. 3, the scanning head 16 is sent out for one line in the driving direction 114 by the guide 18. Thereafter, similar processing is repeated to obtain image data over the entire surface of the substrate 1.

  The illumination unit 30 includes a side illumination source 102 provided with an acrylic sheet 104 at a lower portion, and a total reflection mirror 108. The acrylic sheet 104 has an action of diffusing side light from the side illumination source 102. Since the side illumination source 102 is an aggregate of LEDs that are point light sources, if there is no diffusing action, there is a concern that spot-like light is reflected in image data and adversely affects inspection accuracy.

  As shown in FIG. 3, the two side illumination sources 102 have an ultraviolet light source 102a having three rows of ultraviolet LED groups and a visible light source 102b having one row of white LED groups, and go to the line 112 under inspection. Inclined for efficient side light. The reflected light from the line 112 that has received the illumination light is reflected by the mirror 108 and directed to the lens 32. The ultraviolet light source 102a and the visible light source 102b have separate power sources (not shown) so that the lighting control can be performed independently of each other.

  FIG. 4 shows the configuration of the line sensor 34. The line sensor 34 includes a red imaging element array 150, a green imaging element array 152, and a blue imaging element array 154, each of which corresponds to one of RGB three colors. These element arrays are configured by arranging 5000 to 10000 image sensors 162. The red image pickup device array 150 is provided with a red color filter 156 for extracting a red component on an incident surface thereof. Similarly, a green color filter 158 for extracting a green component and a blue color filter 160 for extracting a blue component are provided on the incident surfaces of the green image sensor array 152 and the blue image sensor array 154, respectively. The red image sensor column 150 and the green image sensor column 152, and the green image sensor column 152 and the blue image sensor column 154 each maintain a pitch of ΔC. Therefore, the line sensor 34 outputs a red component image, a blue component image, and a green component image to the main unit 12.

  In these RGB three-color images, a slight positional deviation occurs due to the pitch ΔC. By combining the images while correcting the position to eliminate the positional deviation, an inspection image without deviation is generated. The position correction and composition of the RGB three-color image may be executed by the memory control unit when fetching from the line sensor 34 to the memory 44, or the RGB three-color image may be fetched separately into the memory 44 and later analyzed. Position correction and composition may be executed by Further, the analysis unit 46 may select any of the RGB three-color images as the inspection image.

  FIG. 5 is a diagram showing an example of the configuration of the analysis unit 46 according to an embodiment of the present invention. The analysis unit includes an inspection unit 70 and an image processing unit 72. The image processing unit 72 reads the image data from the memory 44 to generate an inspection image, and gives the inspection image to the inspection unit 70. The image processing unit 72 includes a position correction unit 74, a position specifying unit 75, and a shading correction unit 76. The inspection unit 70 determines pass / fail for each inspection item based on the determination criterion and the inspected image recorded in the determination criterion storage unit 48 in advance. In the case of failure, the inspection unit 70 specifies the application state of the coating or the position of the abnormality detected on the substrate surface on the inspected image.

  FIG. 6 is a flowchart showing an inspection procedure of the coating inspection apparatus 10 having the above configuration. The lighting of the ultraviolet light and the lighting of the visible light are selected according to the synchronization signal, and both the fluorescent image and the visible light image by the ultraviolet light are individually and while the scanning head 16 moves once on the substrate 1. Form at once. Here, an inspection procedure by a switching scanning method in which odd lines including the first line as a start position are set for ultraviolet light image acquisition and even lines are set for visible light is shown. For this reason, it is assumed that the image resolution by the coating inspection apparatus 10 is sufficiently high, and even if an image is acquired every several lines, it sufficiently withstands the inspection purpose.

  First, the ultraviolet illumination mode which is the first mode is selected, and the scanning head 16 is sent to the start position (S50). With the selection of the ultraviolet light illumination mode, the head control unit 40 puts the ultraviolet light source 102a in the side illumination source 102 in the on state and the visible light source 102b in the off state. Under the ultraviolet light illumination, the first line is imaged by the line sensor 34 (S52), and the image data 54 is written into the memory 44 (S54).

  Subsequently, the scanning head 16 is fed by one line in the driving direction by the head control unit 40 (S56), and the position is the scanning end position, that is, the end end of the substrate 1, in accordance with the information relating to the substrate 1 inputted in advance. It is determined whether or not there is (S58). If it is not the end position (N in S58), switching to the visible light illumination mode is performed (S60). With the selection of the visible light illumination mode, the head control unit 40 puts the ultraviolet light source 102a out of the side illumination source 102 and turns on the visible light source 102b. Under visible light illumination, the second line is imaged by the line sensor 34, the image data 54 is written to the memory 44, and the scanning head 16 is advanced (S52, S54, S56). The processes from S52 to S60 are repeated until the scanning head 16 reaches the end position, and an odd-numbered line image is formed by fluorescence generated by ultraviolet light illumination, while an even-numbered line image is formed by visible light illumination. According to this interleave method, a plurality of images can be acquired by passing the substrate 1 once under the scanning head, and the inspection time can be shortened.

  If the scanning head 16 reaches the end position, the process proceeds from Y in S58 to S62. In step S62, the analysis unit 46 inspects the application state of the surface coating on the substrate 1. The acceptance criteria for the coating application state inspection and other information are read from the criteria storage 48 and used. When the inspection is finished, the result is displayed (S64), and the series of processing is finished. Pass / fail may be recorded in the memory 44 as well as displayed. When the inspection process for the subsequent substrate 1 flowing on the conveyor of the support base 22 is continued, the processes from S50 to S64 are similarly performed on the substrate 1. In this way, the inspection process can be continuously performed on the substrate 1 that flows sequentially.

  FIG. 7 is a flowchart showing a coating inspection process S62 according to an embodiment of the present invention. In this inspection process, first, the position deviation of the visible light image is corrected by specifying the amount of positional deviation of the substrate in the visible light image. Then, position correction equivalent to the visible light image is also performed on the ultraviolet light image. After correcting the position of the ultraviolet light image based on the visible light image as described above, the coating inspection is performed based on the ultraviolet light image. In this embodiment, a visible light image and an ultraviolet light image are simultaneously acquired by an interleave method. Therefore, by correcting the position of the ultraviolet light image using the positional deviation amount of the visible light image, it can be corrected with high accuracy.

  As shown in FIG. 7, the image processing unit 72 reads a visible light image from the memory 44 and specifies the position of the substrate 1 in the visible light image (S70). Although the substrate 1 is held at a predetermined position on the support base 22, a certain amount of positional deviation is allowed when the substrate 1 is carried into the inspection apparatus 10. The position specifying unit 75 detects a reference mark on the substrate in the visible light image. As a result, the position of the substrate can be specified. The position correction unit 74 determines the amount of positional deviation of the substrate 1 by recognizing the reference mark position specified by the position specifying unit 75 on the visible light image.

  The reference mark is formed in advance on the surface of the substrate 1 and has a high contrast so that detection is easy. For example, the reference mark has a silver outline and a black interior, and is formed at two corners of the substrate 1 that are diagonal positions. Note that the shape or pattern of the substrate surface or the component surface may be used as a reference mark instead of such a position-specific mark.

  The position correction unit 74 determines whether or not the positional deviation amount of the substrate 1 is within the correctable range (S71). If the amount of positional deviation is considerably large and outside the correctable range (N in S71), the inspection is repeated. For example, the position specifying unit 75 specifies the reference mark position again, and the position correcting unit 74 recalculates the positional deviation amount. The visible light image and the ultraviolet light image shown in FIG. 6 may be acquired again. Alternatively, when the amount of positional deviation is outside the correctable range, the inspection unit 70 may stop the inspection.

  When the amount of misalignment is within the correctable range (Y in S71), the position correcting unit 74 corrects the position of the ultraviolet light image using the amount of misalignment of the substrate 1 specified from the visible light image ( S72). For example, the position correction unit 74 sets the inspection range in the ultraviolet light image in consideration of the positional deviation amount of the substrate 1 specified from the visible light image. When the coating application region is a part of the substrate surface, a part of the substrate surface including the coating region may be set as the inspection range.

  Note that the position correction unit 74 may determine whether the positional deviation amount of the substrate 1 is within an allowable range. If the positional deviation amount is within the allowable range, the position correction process (S72) is omitted, and the process proceeds to the next inspected image generation process (S74). If the amount of positional deviation exceeds the allowable range, the position correction unit 74 executes position correction processing (S72). For example, the allowable range is set to a range in which inspection can be performed with sufficient accuracy without performing position correction.

  In addition to the image position correction process, the shading correction unit 76 may adjust the brightness of the visible light image and the ultraviolet light image. The shading correction unit 76 adjusts the visible light image and the ultraviolet light image by using the shading correction values for the visible light image and the ultraviolet light image acquired in advance by illuminating the reference plate 60.

  Subsequently, an inspection image is generated or selected (S74). The inspected image is generated or selected by the image processing unit 72 or the inspection unit 70. For example, the image processing unit 72 reads out an inspected image set in advance according to the inspection item and the inspection area from the memory 44. The image processing unit 72 may process at least one of the visible light image and the ultraviolet light image stored in the memory 44 to generate a new image, and select the image as an inspection image.

  In the present embodiment, for example, in coating coating omission inspection and thin coating inspection, since the fluorescence of the coating is typically bluish, the blue component image of the ultraviolet light image is selected as the inspection image. As a result, a sufficiently bright image is obtained at the position where the coating is normally performed, and a dark image is obtained at the paint leakage position, so that the paint leakage inspection can be easily performed. In the bubble inspection, either the blue component image or the green component image of the ultraviolet light image may be selected according to the required inspection accuracy. In other foreign matter inspection, a color image of a visible light image or an ultraviolet light image may be selected as an inspection image.

  The inspection unit 70 compares the image to be inspected with the reference image and makes a pass / fail determination for a predetermined inspection item (S76). Inspection items include coating omission inspection, thin coating inspection, and foreign object inspection. The foreign matter inspection includes bubble inspection and dust inspection. The inspection unit 70 determines that the image is acceptable when the image to be inspected is included within a predetermined allowable range set based on the reference image. For example, the reference image is an average image of a plurality of images determined to be acceptable.

  For example, in the coating omission inspection and the thin coating inspection, the inspection unit 70, for example, when the luminance value of the pixel in the image to be inspected does not satisfy a preset threshold value, the substrate corresponding to the inspection target pixel It is determined that there is omission or light coating in the upper position. Fluorescence intensity is reduced in places where the coating is smeared or thinly coated, and appears darker than the normal application state on the inspected image. For example, the threshold value of the luminance is set to a value obtained by reducing the luminance value of the pixel on the reference image corresponding to the inspection target pixel by a predetermined margin.

  Further, in the bubble inspection, for example, when the luminance value of the pixel in the image to be inspected exceeds a preset threshold value, the inspection unit 70 determines that there is a bubble at a position on the substrate corresponding to the inspection target pixel. judge. This is because light is scattered at the outline of the bubble and appears brighter than the normal application state. For example, the threshold value of luminance is set to a value that is increased by a predetermined margin from the luminance value of the pixel on the reference image corresponding to the pixel to be inspected. Similarly, in the case of other foreign matter inspection, the inspection unit 70 detects, for example, a foreign matter at a position on the substrate corresponding to the pixel to be inspected when the luminance value of the pixel in the image to be inspected is outside a preset allowable range. Judge that there is.

  The inspection unit 70 determines whether or not all inspection items have been inspected (S78), and when all inspections have been completed (Y in S78), the process ends. In this case, the process returns to the display process (S64) shown in FIG. When there is an inspection that has not been completed (N in S78), the selection of the image to be inspected (S74) and the pass / fail determination (S76) are repeated for incomplete inspection items.

  In addition, after all the inspections for the ultraviolet image are completed, the inspection unit 70 may inspect the foreign matter on the inspection object based on the visible light image as a final inspection. Usually, the substrate coating process is the final stage in the electronic substrate manufacturing process. The shipping risk of defective products can be further reduced by adding a final inspection using a visible light image. It is also preferable in that the generated visible light image can be used more meaningfully.

  1 substrate, 10 coating inspection device, 16 scanning head, 30 illumination unit, 34 line sensor, 40 head control unit, 42 memory control unit, 44 memory, 46 analysis unit, 48 judgment criterion storage unit, 70 inspection unit, 72 image processing Department.

Claims (4)

An inspection device for an object to be inspected, in which at least part of the surface is coated with a coating that emits fluorescence in response to ultraviolet light
An ultraviolet light source,
An imaging unit that receives fluorescence from an object to be inspected that has received ultraviolet light, and generates a plurality of images each separated into different color components;
An inspection unit that inspects the coating of the object to be inspected based on at least one of the images generated by the imaging unit ,
The inspection unit selects and inspects one of a plurality of color-separated images for each inspection area,
The inspection unit, the inspection apparatus characterized that you determine the type of coating that is applied to the test zone on the basis of the image of the selected color component.   The inspection apparatus according to claim 1, wherein the inspection unit selects an image according to a foreign object to be inspected from a plurality of color-separated images and inspects the foreign object. The inspection unit, the inspection apparatus according to claim 1 or 2, characterized in that by selecting an image inspecting according to the inspection item from a plurality of different images the dynamic range obtained by the imaging unit. Inspection apparatus according to claim 1, characterized by further comprising a shading correction unit that performs shading correction of the ultraviolet light image based on the intensity of the fluorescence emitted by the reference member which receives the ultraviolet light 3.

Images