JP2008268055A - Foreign material inspecting device, and foreign material inspection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foreign material inspecting device and a foreign material inspection method, capable of inspecting the existence of foreign materials in an assembly line of solid-state imaging element and optical components, and preventing an assembly with foreign material mixed from being delivered in a post-process. <P>SOLUTION: The foreign material inspecting device is provided with a first imaging camera 15 for imaging a jointing surface 2a of the optical component 2 and a second imaging camera 28 for imaging a jointing surface 1a of the solid-state imaging element 1. The optical component 2 held by a holding mechanism part 32 is cured temporarily with an adhesive, such as, UV resin on the solid-state imaging element 1 mounted on an adjusting base 13 to be jointed with the solid-state imaging element 1. In this state, the jointing surface of the solid-state imaging element 1 and the optical component 2 is imaged by the solid-state imaging element 1. The obtained respective image data is stored in a storage means 43, an image processing part 44 detects the contrasting density and distribution state generated by the foreign materials of each pixel, as gradation information and distribution information, and detects the existence of the foreign materials from the relation with previously set prescribed luminance data. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a foreign matter inspection apparatus and a foreign matter inspection method for inspecting foreign matters such as dust, dust, and dust when an optical component such as a solid-state imaging device and a lens is assembled.

2. Description of the Related Art Conventionally, in an endoscope or other optical product, a solid-state imaging device and an optical component such as an optical lens around the solid-state imaging device are sometimes used as an imaging unit in an assembled state. For example, in FIG. 11, the imaging unit 3 is obtained by bonding the solid-state imaging device 1 and the optical component 2 made of, for example, a flat lens or the like with an adhesive layer made of an adhesive such as UV resin.
In the assembling process of these imaging units 3, standards for dust, dust, dust and the like mixed during the assembling process are strictly determined. Should these dust, dust, and dust appear in the output image of the solid-state image sensor itself that is bonded to the optical component, the assembled imaging unit becomes a defective product, and is the imaging unit discarded as a defective product? It is necessary to reassemble after removing the dust, dust, and dust that have been decomposed and mixed.
Therefore, a technique for inspecting these foreign substances before and after assembling the imaging unit is essential, and various foreign substance inspection methods are employed.

As such a foreign substance inspection apparatus and method, there exists what was described in the following patent document 1, for example. In the foreign substance inspection apparatus 100 described in Patent Document 1 shown in FIG. 12, the illumination means 102 illuminates the surface of the specimen 101 conveyed along the rail, and foreign substances such as dust, dust, and dust are externally applied. The image is taken by the imaging means 103. The image captured by the imaging unit 103 is temporarily stored in the storage unit 105 in the control device 104. When necessary, the data is read from the storage unit 105, and the image processing unit 106 reads the density information for each pixel in the captured image to detect the presence or absence of a foreign object. When there is a foreign object, the size and position of the foreign object are detected.
In this foreign matter inspection apparatus 100, foreign matters having a size equal to or larger than the resolution for each pixel of the imaging means 103 and the image processing unit 106 can be detected with an accuracy corresponding to the gradation level of the storage means 105 and the image processing unit 106. Whether the inspection of the foreign matter is acceptable or not is determined by the control device 104. Based on the result of the acceptance / rejection, the discharge switching unit 107 classifies the defective product and the defective product, and rejects the defective product. It can be said that the foreign object inspection apparatus 100 is an off-line inspection apparatus that inspects the test object 101 alone separately from the assembly line.

On the other hand, Patent Document 2 is a defect inspection apparatus for a solid-state image sensor, which is a technique for detecting the number and positions of defective pixels by comparing the grayscale output of each pixel of the solid-state image sensor itself with a predetermined grayscale level. This defect inspection apparatus is a technique that can also be applied to inspection of foreign matters such as dust and dirt.
In this defect inspection method as well, as in Patent Document 1, foreign matter having a resolution equal to or larger than the resolution per pixel of the solid-state imaging device itself can be detected with a precision corresponding to the gradation level, and generally an assembled article. This is performed at the time of final evaluation or inspection of a single part.
JP-A-7-280738 JP-A-6-315112

However, as in the prior art described above, the foreign matter inspection by the external image pickup means and the foreign matter inspection by the solid-state image pickup device are inspections performed separately from the assembly line of the optical component before or after the assembly of the optical component. Even if the above-described foreign matter inspection is performed on the optical component alone before introducing the optical component for assembly into the assembly device, foreign matters such as dust are mixed when the optical component is subsequently carried into the assembly device. If there is a danger and foreign matter enters and adheres when the optical component is carried in, there is no detection means, and the assembly work is performed in a state where foreign matter is mixed.
In such a case, it was only possible to detect that foreign matter was mixed in the joint portion of the optical component by performing foreign matter inspection on the assembled optical component unit. For this reason, it is necessary to disassemble the assembled optical component unit to remove foreign matter, and then reassemble it. This results in a significant loss of assembly time and damages the optical components such as the solid-state image sensor and lens when disassembled. There was a drawback that the amount of damage would be enormous.

  In view of such circumstances, the present invention is capable of inspecting the presence or absence of foreign matter on an assembly line of a solid-state imaging device and an optical component, and prevents foreign substances from being mixed into a subsequent process. And a foreign matter inspection method.

A foreign matter inspection apparatus according to the present invention is a foreign matter inspection device for inspecting the presence or absence of foreign matter on a joint surface between a solid-state imaging device and an optical component, and each joint surface between the solid-state imaging device and the optical component before joining is subjected to a first treatment. An image, an imaging unit that captures an image as a second processed image, a solid-state image sensor that captures, as a third processed image, a joint surface between the solid-state imaging element and the optical component that are separably bonded, a first processed image, A storage means for storing the second processed image and the third processed image, and a foreign object is detected by image processing for each of the first processed image, the second processed image, and the third processed image read from the storage means. And an image processing unit.
The foreign matter inspection method according to the present invention is a foreign matter inspection method for inspecting the presence / absence of foreign matter on a joint surface between a solid-state image sensor and an optical component. A first imaging step for capturing an image to be processed and a second processed image; a first inspection step for detecting foreign matter by image processing based on the first processed image and the second processed image; a solid-state imaging device and an optical device An assembling step in which the parts are separably joined at each joining surface, a second imaging step in which the joining surface of the joined solid-state imaging device and the optical component is imaged as a third processed image by the solid-state imaging device, and a third And a second inspection step for detecting foreign matter by image processing based on the image to be processed.

According to the foreign matter inspection apparatus and the foreign matter inspection method of the present invention, each joint surface between the solid-state imaging device and the optical component before joining is imaged, and each of the joint surfaces is inspected by the image processing unit. If foreign matter is detected, it is removed. And in the state which joined each separation surface of these solid-state image sensors and optical parts so that separation was possible, it was detected whether the joint surface contained a foreign material by the solid-state image sensor, and when a foreign material was detected, it was joined solid By separating the image sensor and the optical component, removing the foreign matter, and re-joining, a unit that does not include the foreign matter on the joint surface can be manufactured while examining the foreign matter.
In the foreign matter inspection method according to the present invention, a first imaging step of picking up an image of the solid-state imaging device and the optical component, and a first inspection step of detecting foreign matter by image processing based on the first processed image and the second processed image Means that the solid-state imaging device and the optical component may be individually and continuously subjected to foreign matter inspection by imaging and image processing, or the first inspection step may be performed after the first imaging step.

In the foreign matter inspection apparatus and the foreign matter inspection method according to the present invention, the image processing unit determines the density and distribution state of the foreign matter for each pixel for each of the first processed image, the second processed image, and the third processed image. It is preferable to detect the presence or absence of foreign matter by detecting the tone information and the distribution information.
For each of the first processed image, the second processed image, and the third processed image, the shade information (luminance data) that detects the shade of the shadow caused by the foreign matter and its distribution state as gradation information and distribution information for each pixel. ) Can be detected as a foreign object in relation to a predetermined luminance value. Thereby, it is possible to perform a foreign object inspection with high accuracy for each pixel.

In the foreign matter inspection apparatus and the foreign matter inspection method according to the present invention, the image processing unit includes the entire image or a plurality of divided image areas for each of the first processed image, the second processed image, and the third processed image. Foreign matter may be detected based on the accumulated luminance value information.
In this case, the luminance accumulated value information is detected for each image area or one divided image area, and foreign matter can be detected for each image area in relation to the previously defined accumulated luminance value information. Since foreign matter is detected for each image area, foreign matter inspection can be performed in a shorter time than detection for each pixel.

The image processing unit detects the position information of the solid-state imaging device and the optical component based on the grayscale image of each pixel for each of the first processed image and the second processed image, and based on these position information You may make it join an image pick-up element and an optical component so that isolation | separation is possible on a joint surface.
At the time of joining, by detecting the position information of the solid-state imaging device and the optical component from the grayscale image of each pixel, the joining position of each joining surface can be accurately set and assembled.

In the foreign matter inspection method according to the present invention, the solid-state imaging device and the optical component are held in a separable state in the assembly step, the second imaging step and the second inspection step are processed, and then the solid-state imaging device We decided to fix the optical parts so that they would not separate.
Before the second imaging step and the second inspection step, the solid-state imaging device and the optical component are joined in a separable manner with an adhesive such as UV resin, and foreign matter is mixed in the joint surface between the solid-state imaging device and the optical component. Since it is fixed so as not to be separated after confirming that there is no foreign matter, it should be possible to separate and remove the solid-state imaging device and the optical component without any possibility of damage if foreign matter is mixed.

In addition, in the second imaging step, the illumination unit irradiates the joint surface with the solid-state image sensor through the translucent optical component, and in this state, the solid-state image sensor includes a surface facing the joint surface of the optical component. You may make it image-pick by setting to the depth which is not.
Illumination light is irradiated to the joint surface through the surface opposite to the joint surface of the optical component with the solid-state image sensor, and when the joint surface is imaged by the solid-state image sensor, the focal depth is reduced to the surface opposite to the optical component. Even if a foreign object adheres, it is not included in the captured image.

According to the foreign matter inspection apparatus and the foreign matter inspection method according to the present invention, it is possible to image each of the joint surfaces of the solid-state imaging device and the optical component before joining and in the joined state. If foreign matter is detected on the joint surface, remove the foreign matter. If foreign matter is detected on the joint surface in the joined state, separate the solid-state image sensor and optical components from the joined state, remove the foreign matter, and then join again. Therefore, it is possible to prevent the unit of the solid-state imaging device and the optical component mixed with foreign matter from being conveyed to a subsequent process. As a result, it is possible to reliably prevent the trouble of separating and reassembling after the solid-state image sensor and the optical component are joined and solidified, eliminating the foreign matter, and damaging the solid-state image sensor and the optical component at that time. Can be significantly reduced.
Further, the foreign matter inspection apparatus and method according to the present invention can be employed in the assembly line to efficiently manufacture the unit and foreign matter, thereby suppressing the manufacturing cost and improving the yield.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
A foreign substance inspection apparatus according to a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is an explanatory diagram showing the overall configuration of the foreign substance inspection apparatus according to the first embodiment, and FIG. 2 shows a first imaging process on the second imaging unit side that images a solid-state imaging device by the second imaging unit of the foreign substance inspection apparatus. 3A is a perspective view of the solid-state imaging device, FIG. 3B is a diagram showing an effective pixel portion to which foreign matter is attached, and FIG. 4 is a foreign matter on the m-th column pixel in the first processed image of the solid-state imaging device. FIG. 5 is a diagram illustrating a luminance distribution including foreign matters on the n-row pixels, and FIGS. 6 to 9 are diagrams illustrating a first imaging unit side that images an optical component by the first imaging unit. It is a figure which shows the principal part of the foreign material inspection apparatus similar to FIG. 1 which shows one imaging process, an adhesive agent application process, an assembly process, and a 2nd imaging process.
In FIG. 1, the solid-state imaging device 1 is provided on an assembly line for manufacturing an imaging unit 3 (see FIG. 11) by joining an optical component 2 including a flat lens and various lenses positioned in the vicinity thereof. An overall schematic configuration of the foreign matter inspection apparatus 10 is shown. The foreign matter inspection apparatus 10 is provided with a frame body 11 having a rectangular frame shape, for example, and includes a foreign matter inspection mechanism and an assembly mechanism. Assume that assembly lines are arranged in a direction perpendicular to the paper surface shown in FIG.

In the foreign matter inspection apparatus 10 shown in FIG. 1, a base portion 12 is provided on a frame body 11, and an adjustment base on which the solid-state imaging device 1 is placed and supported in a suction fixed state by suction means or the like on the base portion 12. 13 is provided. The adjustment table 13 can be rotated horizontally with respect to the vertical axis, and the angle of the joint surface 1a of the solid-state imaging device 1 can be adjusted in the direction of multiple degrees of freedom with respect to the horizontal plane. Here, the multi-degree-of-freedom direction is, for example, a direction in which the joint surface 1a is inclined within a range of 360 degrees around the fulcrum when the intersection of the joint surface 1a and the rotation axis of the adjustment base 13 is a fulcrum, ie, solid-state imaging The direction of the vertical inclination angle (elevation angle) with respect to the horizontal plane of the joint surface 1a, which is the surface of the element 1, refers to the vertical inclination angle (elevation angle) is the tilt angle.
The solid-state imaging device 1 transported on the assembly line is placed on the adjustment table 13 by an automatic transport mechanism (not shown) or a worker.
A first imaging unit 14 is provided on the base unit 12 adjacent to the adjustment table 13. In the first imaging unit 14, a first imaging camera 15 is provided as a first imaging unit for imaging a joint surface 2 a of the optical component 2 described later, and above the first imaging camera 15, outside the imaging optical path. For example, ring-shaped illuminating means 16 is disposed to surround the imaging optical path. The illumination means 16 emits illumination light in a truncated conical direction indicated by hatching in the figure.

Supports 18a and 18b are fixed in an upright state at both ends of the base part 12, and a transfer stage 19 is provided by connecting upper ends of the supports 18a and 18b. A support unit 20 is slidably held on the transfer stage 19. The support unit 20 can be moved in a three-dimensional direction by the transfer stage 19. Here, the three-dimensional direction means a three-dimensional direction of the X axis (horizontal direction), the Y axis (Y direction perpendicular to the paper surface), and the Z axis (vertical direction) in this embodiment.
Further, the support unit 20 includes a second imaging unit 22 for imaging the joint surface 1a of the solid-state imaging device 1 from above, and an appropriate type of optical lens (here, a flat lens) assembled with the individual imaging device 1. ) And the like, an optical component holding unit 23 for holding the optical component 2 including the adhesive, an adhesive supply means 24 for supplying an adhesive for bonding the solid-state imaging device 1 and the optical component 2, and a separable bonded state. The solid-state imaging device 1 and a foreign substance inspection unit 25 that images the joint surface of the optical component 2 are provided, which are respectively provided by linear motion linear guides 26a, 26b, 26c, 26d and fixed plates 27, 31, 34, 36. It is supported so as to be able to advance and retract in the vertical direction (Z-axis direction).

In the second imaging unit 22, a second imaging camera 28 is provided as a second imaging means on a fixed plate 27 supported by a linear guide 26a so as to move up and down, and the second imaging camera 28 is located below the solid-state imaging device 1. Is taken to check the position and to inspect the foreign matter. For example, a ring-shaped illumination unit 29 for illuminating the joint surface 1 a of the solid-state imaging device 1 supported by the adjustment table 13 is provided below the second imaging camera 28. Illumination light is emitted by the illumination means 29 in a truncated conical direction indicated by hatching in the figure.
In the optical component holding unit 23, a gripping mechanism unit 32 is attached to a fixed plate 31 supported by a linear guide 26b so as to be movable up and down, and a suction unit 32a that sucks and holds the optical component 2 at the tip (lower end) of the gripping mechanism unit 32. Is provided. The optical component 2 conveyed on the assembly line is supplied by an automatic conveyance mechanism (not shown) or a worker and is adsorbed by the adsorption unit 32a.
In the adhesive supply means 24, an adhesive application syringe 35 is provided as an adhesive application means on a fixed plate 34 supported by a linear guide 26c so as to be movable up and down. As the adhesive s applied from the adhesive application cylinder 35 onto the joint surface 1a of the solid-state imaging device 1, for example, an ultraviolet curable resin such as a UV resin is used. The adhesive s can be set to a temporarily cured state where the bonding surface 1a and the bonding surface 2a are separably cured and a cured state so as not to be separated depending on the irradiation time (irradiation amount) of ultraviolet rays.
In the foreign matter inspection unit 25, a fixed plate 36 is supported by a linear guide 26d so as to be movable up and down. On the upper side of the fixed plate 36, for example, a surface illumination unit 37 is attached as a transmission type illumination unit, and on the lower side of the surface illumination unit 37, for example, a transparent or translucent diffusion plate (or glass chart) 38 is attached. ing. The surface illumination means 37 emits illumination light in a truncated conical direction indicated by hatching in the figure.

In the support unit 20, the fixed plates 27, 31, 34, and 36 supported by the linear guides 26a, 26b, 26c, and 26d so as to be movable up and down are independently moved up and down by a drive mechanism such as an air cylinder (not shown). It is possible to move in the direction.
Moreover, in the foreign material inspection apparatus 10 according to the present embodiment, the first imaging camera 15 and the second imaging camera 28 only image the bonding surface 2a of the optical component 2 and the bonding surface 1a of the solid-state imaging device 1 before bonding. Instead, the solid-state imaging device 1 is configured to image the joint surfaces 1a and 2a in the temporarily cured state of the solid-state imaging device 1 and the optical component 2 in the joined state by the adhesive S. For this reason, a power supply mechanism 40 for supplying power to the solid-state imaging device 1 supported on the adjustment table 13 is provided.
Then, each captured image captured by each of the first imaging camera 15, the second imaging camera 28, and the solid-state imaging device 1 is input to the storage means 43 such as a capture board in the control controller 42 as an image to be processed, and once. Remembered.
An image processing unit 44 is disposed in the control controller 42, and the joint surface 1 a of the solid-state image sensor 1 before joining and the optical components captured by the image processing unit 44 with the second imaging camera 28 and the first imaging camera 15, respectively. Each captured image of the two joint surfaces 2a is subjected to image processing as a first processed image and a second processed image. In addition, the image processing unit 44 performs image processing on the captured images of the joint surfaces 1a and 2a between the individual imaging device 1 and the optical component 2 captured by the solid-state imaging device 1 as a third processed image.
In addition, a display monitor 45 is connected to the controller 42, displays image information stored in the storage means 43 and a processed image subjected to image processing, and is used for a control instruction and an operation monitor. .

Here, in the image processing unit 44, the first processed image and the second processed image stored in the storage unit 43 are read as appropriate, and the outer shape of the bonding surface 1a of the solid-state imaging device 1 and the bonding surface 2a of the optical component 2 is read. Pattern matching is performed by detecting the edge position or the edge position of the imaging area or the positioning mark positions provided on the joint surfaces 1a and 2a, and the position recognition is performed through the position recognition image algorithm to obtain position information.
Also, each processed image file or each processed image data of the first processed image, the second processed image, and the third processed image is read from the storage means 43, and the grayscale image for each pixel is read in order, The gradation and distribution of shadows caused by foreign matter such as dust, dust, etc. are detected as gradation information and distribution information, and the position and size of the foreign matter based on the gradation information and distribution information for each pixel. Can be detected.
In the control controller 42, the gripping mechanism for the solid-state imaging device 1 supported by the adjustment table 13 is based on the position information obtained from the outer edge position or the positioning mark position of each joint surface detected by the image processing unit 44. The positioning of the optical component 2 sucked and held by the unit 32 and the adhesive supply operation by the adhesive application syringe 35 are controlled.
Here, the foreign matter inspection apparatus 10 includes a foreign matter inspection mechanism and an assembly mechanism for the imaging unit 3, and in particular, the first imaging unit 14, the second imaging unit 22, the foreign matter inspection unit 25, the storage unit 43, the image processing unit 44, and the like. Mainly constitutes a foreign matter inspection mechanism, and the optical component holder 23, the adhesive supply means 24, etc. mainly constitute an assembly mechanism.

The foreign matter inspection apparatus 10 according to the present embodiment has the above-described configuration. Next, a foreign matter inspection method using the foreign matter inspection apparatus 10 will be described.
First, in the foreign matter inspection apparatus 10 shown in FIG. 1, the solid-state imaging device 1 that is an assembly part is placed on and supported by an automatic conveyance mechanism or manually on an adjustment table 13 in the frame body 11. Next, based on a command from the controller 42, the support unit 20 is moved in the XY direction along the transport stage 19, and the second imaging camera 28 of the second imaging unit 22 is directly above the solid-state imaging device 1. Further, the support unit 20 is moved downward in the Z-axis direction by a vertical drive mechanism (not shown).
At the same time, in the second imaging unit 22 provided in the support unit 20, the fixing plate 27 is lowered along the linear guide 26 a by a driving mechanism such as an air cylinder (not shown) to lower the second imaging camera 28. The height position of the second imaging camera 28 is set so that the joint surface 1a of the solid-state imaging device 1 is positioned at the working distance height of the second imaging camera 28 as shown in FIG.
In this state, the lighting means 29 of the second image pickup unit 22 is controlled to illuminate, and irradiates the joint surface 1a of the solid-state image sensor 1 (irradiates a truncated conical direction indicated by hatching in the drawing).

And the joint surface 1a of the solid-state image sensor 1 on the adjustment stand 13 is imaged with the 2nd imaging camera 28 (1st imaging process by the 2nd imaging camera 28). The captured image is transmitted as a first processed image to the storage means 43 in the controller 42 and stored in the memory as a first processed image file or two-dimensional grayscale array data in units of pixels.
Next, as a first inspection step, the first processed image stored in the storage unit 43 is read out as a first processed image file or two-dimensional grayscale array data in units of pixels, and the image processing unit 44 reads the solid-state image sensor 1. The external shape of the joint surface 1a or the edge of the imaging area is detected, or the position of the positioning mark provided on the joint surface 1a is accurately detected through a position recognition image algorithm such as pattern matching to recognize the position of the solid-state imaging device 1. And detected as position information (first inspection step of the solid-state imaging device 1).
Thereafter, the first processed image file corresponding to the first processed image stored in the storage means 43 or the two-dimensional grayscale array data in pixel units is read again, and the image processing unit 44 performs solid-state imaging from the grayscale information for each pixel. Whether or not there is a foreign matter e such as dust, dust, or dust on the joint surface 1a on the element 1, and if there is a foreign matter e (see FIG. 3), the size and position of the foreign matter e are detected. If foreign matter e is detected, the assembling operation is temporarily terminated, a message indicating that foreign matter e has been detected is displayed on display monitor 45, and the removal of foreign matter e is left to the operator. After removing the foreign matter e, the assembly work is resumed.

Next, an algorithm for detecting foreign matter on the joint surface 1a of the solid-state imaging device 1 described above performed in the image processing unit 44 will be described.
FIG. 3 shows the solid-state imaging device 1, and in FIGS. 3A and 3B, a frame portion 1b having, for example, a rectangular frame shape is provided on the joint surface 1a (front surface), and effective pixels are provided in the frame portion 1b. Part 1c is provided. Here, in the pixels arranged in a matrix of (i columns × j rows) in the effective pixel portion 1c of the solid-state imaging device 1 shown in FIG. 3B, the foreign object e has a coordinate position (m, n) (where It is assumed that the pixel adheres to a pixel of m ≦ i; n ≦ j).
4 and 5 show the luminance distribution in the first processed image of the solid-state imaging device 1 as described above. FIG. 4 shows the m-th column grayscale pixel data on the horizontal axis and the vertical axis on the grayscale information ( It is a figure of the luminance distribution made into (luminance data). In FIG. 4, the luminance distribution falls into a valley shape from the normal luminance value of the effective pixel portion 1c without the foreign matter e, with the nth row being the position center of the foreign matter e as the center. The width ea of the depressed portion coincides with the foreign substance diameter in the vertical direction.
Further, FIG. 5 is a diagram showing a luminance distribution in which the n-th row of gray pixel data is the horizontal axis and the vertical axis is the gray information (luminance data). In FIG. 5, the luminance distribution falls in a valley shape from the normal luminance value with the m-th column as the center of the position of the foreign substance e. In this case, the width eb of the depressed portion coincides with the diameter of the foreign material e in the lateral direction.
However, the area where the foreign matter is detected is not the entire image of the captured joint surface 1a, but the detection of the region of only the effective pixel portion 1c inside the joint surface 1a after recognizing the outer position of the joint surface 1a of the solid-state imaging device 1. It is assumed that a masking process for performing is performed.

Then, the image processing unit 44 scans the brightness distribution of the luminance data corresponding to the first processed image read from the storage unit 43 in the column direction and the row direction, and is requested as shown in FIGS. A location where the brightness value is smaller than the prescribed brightness values pi and pj that are preset based on the detection accuracy is determined as the location of the foreign object e. Then, the pixel widths ea and eb of the portions below the specified luminance values pi and pj are detected as the diameters of the foreign matter e in the vertical and horizontal directions, respectively, and the pixel width ea and the pixel width ea in the column direction and the row direction of the pixel position determined as the foreign matter e. The middle point of eb is detected and recognized as the center coordinate of the foreign object e.
Here, with respect to the coordinates (m, n) of the foreign object e, the particle analysis is performed by the image processing unit 44, and the center of gravity position of the detected particles is used as the coordinates, or the brightness data corresponding to the first processed image is shaded. The distribution is scanned in the column direction and the row direction, and the position where the luminance value is the lowest among the regions determined to be the location of the foreign object e below the specified luminance value is defined as the coordinate.
After completion of the foreign matter inspection, the illumination unit 29 is turned off by a command from the controller 42.
In the above description, the foreign object detection method by the image processing unit 44 in the first processed image on the joint surface 1a of the solid-state imaging device 1 has been described. However, the joint surface 2a of the optical component 2 described later by the same method. It is assumed that the present invention is also applied to foreign object detection in the second processed image and foreign object detection in the third processed image of the bonded surfaces 1a and 2a of the joined solid-state imaging device 1 and optical component 2.

Then, based on a command from the controller 42, the optical component 2 to be assembled is sucked and gripped by the gripping mechanism 32, and supported to the position where the optical component 2 is directly above the first imaging camera 15 with respect to the transport stage 19. The unit 20 is moved. Next, as shown in FIG. 6, the support unit 20 is lowered by a vertical drive mechanism (not shown), and a fixing plate 31 is moved along the linear guide 26 b with respect to the support unit 20 by a drive mechanism such as an air cylinder (not shown). Then, the gripping mechanism 32 is lowered to such a height that the joint surface 2a (lower surface) of the optical component 2 finally comes to the working distance height of the first imaging camera 15.
In this state, the illumination means 16 is turned on to illuminate the joint surface 2a of the optical component 2. Then, the optical component 2 sucked and held by the holding mechanism unit 32 is picked up by the first image pickup camera 15 (first image pickup step by the first image pickup camera 15), and the picked up image is solid-state picked up as a second processed image. Similar to the first processed image of the element 1, it is transmitted to the storage means 43 in the controller 42, and is stored as a second processed image file or two-dimensional grayscale array data in units of pixels.

Then, the second processed image file corresponding to the second processed image or the two-dimensional grayscale array data (second processed image data) in pixel units is read from the storage means 43, and the image processing unit 44 performs the above-described solid processing. Similar to the image processing by the image processing unit 44 of the captured image of the image sensor 1, precise position recognition of the optical component is performed through the position recognition image algorithm such as edge detection and pattern matching of the outer shape of the joint surface 2a of the optical component 2, Detect as location information. Further, after the position recognition, the second processed image file or the two-dimensional grayscale array data in units of pixels is read again from the storage means 43, and dust or the like is deposited on the joint surface 2a on the optical component 2 based on the grayscale information for each pixel. If there is a foreign material e, the size and position of the foreign material e are detected from the density information (first inspection step of the optical component 2).
The foreign matter detection algorithm here is the same as the foreign matter inspection on the joint surface 1a of the solid-state imaging device 1 described above. Even in this case, the foreign object inspection area is not the entire captured image, but only the region that adheres to the bonding surface 1a of the solid-state imaging device 1 is detected after the outer position of the bonding surface 2a of the optical component 2 is recognized. It is assumed that a masking process is performed.
Also in this case, when the foreign object e is detected, the assembling operation is temporarily terminated at that stage, the display device 45 displays that the foreign object e has been detected, and the removal of the foreign object e is left to the operator. . After that, the assembly is resumed.
The illumination means 16 is turned off after the foreign object inspection of the optical component 2 is completed.

Next, as an adhesive application step, the support unit 20 is moved with respect to the transport stage 19 based on an instruction from the controller 42, and the adhesive application syringe 35 of the adhesive supply unit 24 is attached to the bonding surface of the solid-state imaging device 1. Located just above 1a. Then, the support unit 20 is moved downward by a vertical drive mechanism (not shown), and at the same time, the fixed plate 34 is lowered on the support unit 20 along a linear guide 26c by a drive mechanism such as an air cylinder (not shown).
Ultimately, the height of the needle tip of the adhesive application syringe 35 is such that it comes to a position on the joint surface 1a of the solid-state imaging device 1 with a small clearance according to the application amount of the adhesive s such as UV resin. Move to. Then, as shown in FIG. 7, a certain amount of adhesive s is applied onto the bonding surface 1a.
Next, in accordance with a command from the controller 42, the support unit 20 is moved with respect to the transport stage 19, and the solid-state image pickup device 1 is moved in a state where the gripping mechanism unit 32 of the optical component holding unit 23 holds the optical component 2 by suction. It is located right above the joint surface 1a. Then, the support unit 20 is moved downward by a vertical drive mechanism (not shown), and at the same time, the fixing plate 31 is lowered on the support unit 20 along a linear guide 26b by a drive mechanism such as an air cylinder (not shown).
As shown in FIG. 8, the optical component 2 sucked and held by the gripping mechanism portion 32 is bonded to the bonding surface 1a of the solid-state imaging device 1 by the adhesive s at the bonding surface 2a. In this way, the assembly operation of the solid-state imaging device 1 and the optical component 2 is performed (assembly process).

In the assembly work of the solid-state imaging device 1 and the optical component 2, the control controller 42 not only sets the joining position of the optical component 2 and the solid-state imaging device 1 by the lowering of the gripping mechanism 32, but also performs solid-state imaging by the adjustment stand 13. By adjusting the tilt angle of the element 1, the parallelism of the joint surfaces 1a and 2a between the solid-state imaging device 1 and the optical component 2 is adjusted.
As a result, the adhesive s is almost uniformly applied to both the joint surfaces 1 a and 2 a of the solid-state imaging device 1 and the optical component 2. Then, the solid imaging device 1 and the optical component 2 coated with the adhesive s are brought into a temporarily cured state that can be separated again, for example, by reducing the amount of ultraviolet irradiation to the adhesive s.
Thereafter, the suction to the optical component 2 by the gripping mechanism portion 32 is released to release the holding of the optical component 2, and then the fixed plate 31 on which the gripping mechanism portion 32 is disposed is raised along the linear guide 26b. Further, by raising the support unit 20, the assembly operation of the solid-state imaging device 1 and the optical component 2 is temporarily completed.

Then, based on a command from the controller 42, the support unit 20 is moved with respect to the transport stage 19, and the foreign matter inspection unit 25 is positioned directly above the solid-state imaging device 1 and the optical component 2 in the temporarily cured state after the assembly work. Let At the same time as the support unit 20 is moved downward by a vertical drive mechanism (not shown), the fixed plate 36 is lowered to a predetermined height position along the linear guide 26d on the support unit 20 by a drive mechanism such as an air cylinder (not shown).
Next, as shown in FIG. 9, the illumination light of the surface illumination means 37 is transmitted through the diffusion plate 38 and diffused so as not to be condensed on the joint surfaces 1a and 2a of the solid-state imaging device 1 and the optical component 2 in the temporarily cured state. By doing so, the bonded surfaces 1a and 2a in the bonded state are uniformly illuminated.

Next, as a second imaging step, a power supply mechanism 40 supplies power to the solid-state imaging device 1 of the temporarily cured imaging unit 3 so that the solid-state imaging device 1 joins the solid-state imaging device 1 and the optical component 2. 1a and 2a are imaged (imaging process by the solid-state image sensor 1). At that time, there is a possibility that foreign matter is attached to the surface opposite to the joint surface 2a of the optical component 2, and the depth of focus of the imaging unit 3 reaches the surface on the opposite side so as not to image the foreign matter on this surface. Set as shallow as possible.
The captured image captured by the solid-state imaging device 1 of the imaging unit 3 is stored as a third processed image in the storage unit 43 in the controller 42 as a third processed image file or as a two-dimensional grayscale array data in units of pixels. Saved in.
Next, as a second inspection step, the third processed image file or two-dimensional grayscale data in units of pixels is read from the storage means 43, and dust is collected on the joint surfaces 1a and 2a of the imaging unit 3 from the grayscale information for each pixel. If there is a foreign object e, the size and position of the foreign object e are detected.

As this foreign matter detection algorithm, an algorithm similar to the algorithm for detecting foreign matter from the captured image of the joint surface 1a of the solid-state imaging device 1 described above is applied.
If foreign matter e is detected here, the display monitor 45 displays that the foreign matter e has been detected and displays the position of the foreign matter e. Then, the assembling operation is interrupted, and the solid-state imaging device 1 and the optical component 2 in the temporarily cured state are disassembled by the operator to remove the foreign matter e, and the assembly is performed again. The disassembly here can be easily separated because the adhesive s of the joints 1a and 2a is in a temporarily cured state. After removing the foreign matter e, the solid-state imaging device 1 and the optical component 2 are joined again and irradiated with ultraviolet rays to completely cure the adhesive e.
Note that the optical component 2 may be adsorbed and separated from the solid-state imaging device 1 by the gripping mechanism unit 32 of the optical component holding unit 23.
When the foreign substance e is not detected from the joint surfaces 1a and 2a of the image pickup unit 3, the solid-state image pickup device 1 and the optical component 2 are assembled by irradiating the adhesive s with ultraviolet rays again to increase the irradiation amount and completely cure. finish.

As described above, according to the foreign matter inspection apparatus 10 and the foreign matter inspection method according to the present embodiment, the joining surfaces 1a and 2a of the solid-state imaging device 1 and the optical component 2 are pre-joined and the solid-state imaging device 1 and the optical component 2 are temporarily attached. The foreign matter e can be inspected in a state where the cured adhesive s is detachably joined, and the foreign matter e is detected on the joining surfaces 1a and 2a of the solid-state imaging device 1 and the optical component 2 before joining. If the foreign matter e is removed between the joining surfaces 1a and 2a in the joined state, the solid-state imaging device 1 and the optical component 2 are separated from the temporarily cured state, the foreign matter is removed, and the joining is performed again. it can. Therefore, it is possible to prevent the imaging unit 3 in which the foreign substance e is mixed from being conveyed to a subsequent process.
As a result, as in the prior art, after the solid-state imaging device 1 and the optical component 2 are joined and solidified, they are disassembled to remove foreign substances and reassembled, and the solid-state imaging device 1 and the optical component 2 are damaged at that time. Etc. can be reliably prevented, and the generation of defective products containing foreign substances can be prevented. Further, the foreign matter can be inspected before and during the assembly on the assembly line or the assembly apparatus, so that the foreign matter inspection and the imaging unit 3 can be efficiently assembled. Therefore, the assembly of the imaging unit 3 is efficient, and the manufacturing cost can be suppressed and the yield can be improved.

The present invention is not limited to the first embodiment described above, and can be changed as appropriate without departing from the spirit of the present invention.
Next, a foreign matter inspection method according to the second embodiment of the present invention will be described. The configuration of the foreign matter inspection apparatus according to this embodiment is the same as that of the foreign matter inspection apparatus 10 according to the first embodiment.
In the second embodiment, only the foreign object detection algorithm by the foreign object inspection apparatus 10 is different, so the configuration and operation of this part will be described.
In the first embodiment, the first and second processed images captured by the second imaging camera 28 and the first imaging camera 15 and the third processed image captured by the solid-state imaging device 1 are stored in the storage means 43 in the control controller 42. The first to third processed images are stored in the storage unit 43 and read out from the storage unit 43 as a processed image file or two-dimensional grayscale array data in units of pixels.
In the second embodiment, the image processing unit 44 does not detect the grayscale information for each pixel, but each image area obtained by dividing one entire screen or one screen of the target effective pixel unit 1C into several regions. Set. Then, the accumulated luminance value in these image areas is obtained and compared with a predetermined reference luminance accumulated value set in advance in the same image area. When the obtained accumulated luminance value falls below the reference luminance accumulated value, the designation is made. It is determined that a foreign object e exists in the image area.
In FIG. 10, as an example, for example, only one area of the effective pixel portion 1c of the joint surface 1a of the solid-state imaging device 1 or the joint surface 2a of the optical component 2 is divided into eight image areas 47, for example. Yes. Then, the accumulated luminance value in each image area 47 is obtained, and when each accumulated luminance value falls below a predetermined value preset in the same image area, it is determined that there is a foreign object e in the image area 47.

This foreign matter inspection method can detect the foreign matter e, but has a drawback that it cannot be specified where the foreign matter e exists in the image area 47. Therefore, it is preferable to set the number of image areas 47 to be divided in order to specify the detection position of the foreign object e as finely as possible.
However, in the foreign substance inspection apparatus 10 and the foreign substance inspection method according to the second embodiment, the processing loop of the processing loop is performed because the foreign substance determination is performed by dividing the image area 47 into one or a plurality of image areas 47 as compared with the case of performing the foreign substance inspection process for each pixel. The number of times is reduced, and the determination time required for detecting a foreign object can be shortened.
In the present invention, a method for detecting a foreign object by image processing is not limited to the method shown in the above-described embodiment, and an appropriate method can be adopted.

It is explanatory drawing which shows the principal part structure of the foreign material inspection apparatus by 1st embodiment of this invention. It is a figure of the 1st imaging process and 1st inspection process which image a solid-state image sensor with the 2nd imaging part of the foreign material inspection apparatus shown in FIG. (A) is a perspective view of a solid-state image sensor, (b) is a figure which shows the foreign material adhering to the effective pixel part of a solid-state image sensor. It is a figure which shows the luminance distribution in case the foreign material on m column pixel is included. It is a figure which shows the luminance distribution in case the foreign material on n row pixel is included. It is a figure which shows the state which images an optical component with the 1st imaging part of a foreign material inspection apparatus. It is a figure which shows the adhesive agent application process which apply | coats an adhesive agent to a solid-state image sensor. It is a figure of the assembly process which shows the state which joined the solid-state image sensor and the optical component so that isolation | separation was possible. It is a figure of the 2nd imaging process and the 2nd inspection process which show the state which images the joint surface of an imaging unit with a solid-state image sensor. It is a figure which shows the state which divided | segmented the effective pixel part of the solid-state image sensor in the foreign material inspection method by 2nd embodiment of this invention by the image process part. (A) is a perspective view showing a separated state, and (b) is a perspective view showing a joined state about a solid-state image sensor and an optical component. It is explanatory drawing which shows schematic structure of the conventional foreign material inspection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid-state image sensor 2 Optical component 3 Imaging unit 13 Adjustment stand 14 1st imaging part 15 1st imaging camera (imaging means)
DESCRIPTION OF SYMBOLS 10 Foreign substance inspection apparatus 19 Conveyance stage 20 Support unit 22 Second imaging part 23 Optical component holding part 24 Adhesive supply means 25 Foreign substance inspection part 28 Second imaging camera (imaging means)
32 Grasping mechanism section 35 Adhesive application syringe 38 Diffusion plate 40 Power feeding mechanism 42 Controller 44 Image processing section 47 Image area

Claims (10)

A foreign matter inspection apparatus for inspecting the presence or absence of foreign matter on a joint surface between a solid-state imaging device and an optical component,
Image pickup means for picking up the respective bonded surfaces of the solid-state imaging element and the optical component before bonding as a first processed image and a second processed image, respectively.
The solid-state imaging device that images the joint surface between the solid-state imaging device and the optical component that are separably separable as a third processed image;
Storage means for storing the first processed image, the second processed image, and the third processed image;
A foreign matter inspection apparatus comprising: an image processing unit that detects foreign matter by image processing for each of the first processed image, the second processed image, and the third processed image read from the storage unit .   The image processing unit detects the density and distribution status of the foreign matter for each pixel for each of the first processed image, the second processed image, and the third processed image as gradation information and distribution information to detect the foreign matter. The foreign matter inspection apparatus according to claim 1, wherein presence or absence is detected.   The image processing unit detects a foreign object based on the accumulated luminance value information of the entire image area or a plurality of divided image areas for each of the first processed image, the second processed image, and the third processed image. The foreign matter inspection device according to claim 1 which was made. The image processing unit detects position information of the solid-state imaging device and the optical component based on a grayscale image of each pixel for each of the first processed image and the second processed image;
The foreign matter inspection apparatus according to claim 1, further comprising an assembly mechanism that joins the solid-state imaging device and the optical component at a joint surface based on the position information. A foreign matter inspection method for inspecting the presence or absence of foreign matter on a joint surface between a solid-state imaging device and an optical component,
A first imaging step of imaging each joining surface of the solid-state imaging device and the optical component before joining as a first processed image and a second processed image, respectively;
A first inspection step of detecting foreign matter by image processing based on the first processed image and the second processed image;
An assembly step of joining the solid-state imaging device and the optical component so as to be separable at each joint surface;
A second imaging step of imaging the bonded surface of the bonded solid-state imaging device and the optical component as a third processed image by the solid-state imaging device;
A foreign matter inspection method comprising: a second inspection step of detecting foreign matter by image processing based on the third processed image.   In the first and second inspection steps, grayscale information and distribution information due to foreign matter are detected for each pixel of the first processed image, the second processed image, and the third processed image during image processing. The foreign matter inspection method according to claim 5, wherein the presence or absence of foreign matter is detected.   In the first and second inspection steps, during image processing, the first processed image, the second processed image, and the third processed image are based on the accumulated luminance value information of the entire image area or a plurality of divided image areas. The foreign matter inspection method according to claim 5, wherein foreign matter is detected.   In the first inspection step, position information on each joint surface between the solid-state imaging element and the optical component is detected from the first processed image and the second processed image, and the solid-state imaging element and the optical are detected based on the position information The foreign matter inspection method according to claim 5, wherein the parts are joined to be separable at the joining surface. Holding the solid-state imaging device and the optical component in a separable state in the assembly step, processing the second imaging step and the second inspection step,
The foreign matter inspection method according to claim 5, wherein the solid-state imaging device and the optical component are fixed so as not to be separated thereafter.   In the second imaging step, the joint surface with the solid-state image sensor is irradiated with illumination means through the light-transmitting optical component, and in this state, the depth of focus is opposed to the joint surface of the optical component by the solid-state image sensor. The foreign matter inspection method according to claim 5, wherein imaging is performed by setting a depth not including a surface.

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