JP6507653B2 - Inspection apparatus and control method of inspection apparatus - Google Patents

Description

  The present invention relates to an inspection apparatus that inspects an object using an image captured in a state where a pattern image is projected onto the object.

  Conventionally, methods for measuring a three-dimensional shape of an object using an image have been studied. For example, in a method called active triangulation or active stereo method, imaging is performed with a projector projecting a pattern image (stripe pattern, dot pattern, etc.) onto an object by a projector, and a pattern or luminance generated depending on the unevenness of the object surface Is a technology for acquiring three-dimensional information of an object by analyzing the change of. As examples of active triangulation methods, phase shift methods, space coding methods, and the like have been put to practical use.

  In these methods, a phenomenon may occur in which light reflected by an object degrades the measurement accuracy of other objects present in the surroundings. This phenomenon will be described with reference to FIG. FIG. 12 shows a measurement system using the imaging device 200 and the projector 201. The light 201 L having a predetermined pattern is projected from the projector 201 onto the object 202, and the projection pattern projected on the surface of the object 202 is imaged by the imaging device 200. At this time, distortion of the projection pattern due to the surface unevenness of the object 202 appears as a change in luminance of the image captured by the imaging device 200. Therefore, the positional relationship between the point on the surface of the projector 201 and the object 202 and the imaging device 200 can be specified based on the luminance change of the image, and the height (three-dimensional position) of the surface of the object 202 can be estimated.

  However, as shown in FIG. 12, when a tall object 203 is present in the vicinity of the object 202, the light 201 L of the projector 201 is specularly reflected or diffusely reflected on the side of the object 203, and the reflected light 203 L is the surface of the object 202. May be illuminated. Then, not only the reflected light (primary reflected light) 201R of the light 201L of the projector 201 but also the reflected light (secondary reflected light) of the light 203L from the object 203 in the light reaching the imaging device 200 from the surface of the object 202 Light) 203R is also included. The secondary reflected light 203R is superimposed as a noise on the projection pattern on the surface of the object 202, which adversely affects the analysis of the projection pattern and causes a measurement error. In this specification, an object that can cause secondary reflection due to light reflected by another object (for example, the object 202 in FIG. 12) is referred to as “secondary reflective object”, and the reflected light that causes secondary reflection is The resulting object (for example, the object 203) is called a "cause object". In addition, the brightness change of the projection pattern resulting from such secondary reflection is called "secondary reflection noise".

  As a countermeasure against secondary reflection noise, in Patent Document 1, a pattern image is irradiated from two or more directions, and a measurement value from which a shadow defect, a specular defect, etc. is removed based on measurement accuracy (reliability) in each direction. The method of performing more accurate measurement of surface shape is proposed by sorting out. However, this conventional method is merely a method of reducing the influence of noise by combining measurement results in a plurality of directions, and does not fundamentally solve the generation of secondary reflection noise. Therefore, in an environment where secondary reflection occurs even if the pattern image is irradiated from any direction (for example, when there are a large number of tall objects in the periphery, etc.), the secondary reflection noise is used in the conventional method. It is difficult to eliminate the influence of

JP, 2012-112952, A

  The present invention has been made in view of the above situation, and in an inspection apparatus for inspecting an object using an image captured in a state where a pattern image is projected onto the object, secondary reflection noise is suppressed and reliability is improved. The object is to provide technology for enabling high measurement and inspection.

In order to achieve the above object, the present invention adopts the following configuration. That is, an inspection apparatus according to the present invention comprises an imaging device, a projection device for projecting a pattern image within the field of view of the imaging device, and an image captured by the imaging device in a state where the pattern image is projected from the projection device. It has an information processor which inspects one or more objects contained in a field of view of the imaging device, and a control device which controls the imaging device and the projection device. In the case where there is a secondary reflection object that can cause secondary reflection due to light reflected by a reflection surface of another object in the field of view of the imaging device, the control device determines that the secondary reflection object is the image After changing the position of the secondary reflecting object in the field of view of the imaging device so as to come to the center position in the field of view of the device, the pattern image projected from the projection device so that light does not hit the reflecting surface The projection range is changed to a predetermined range at the center of the field of view, and control is performed to capture the secondary reflective object by the imaging device in a state where the pattern image whose projection range has been changed is projected.

  According to this configuration, when there is a secondary reflection object in the field of view of the imaging device, the projection range of the pattern image so that light (pattern image) does not hit the reflection surface of the cause object causing the secondary reflection. Is changed. Therefore, the occurrence of secondary reflection noise can be suppressed, and the projection pattern on the object can be accurately imaged (observed), and the accuracy of measurement and inspection of the object can be improved.

  The image processing apparatus further includes a storage device that stores an inspection program including information for identifying a secondary reflective object from among a plurality of objects to be inspected, the control device based on the inspection program. It is preferable to determine whether there is a secondary reflecting object in the field of view of By creating such an inspection program in advance and setting it in the inspection device, detection of the secondary reflective object in the field of view can be performed easily and accurately, and the processing time for measurement and inspection can be shortened and the accuracy improved. Can be

  Further, the inspection program includes information of imaging conditions when imaging a secondary reflective object, and the control device projects when imaging the secondary reflective object based on the information of the imaging condition. It is also preferable to change the projection range of the pattern image. As described above, by setting the imaging conditions of each of the secondary reflecting objects in advance to the inspection device, the change control of the projection range for suppressing the secondary reflection can be performed easily and accurately, and the measurement and inspection can be performed. Processing time can be shortened and accuracy can be improved.

  The control device further includes a pattern image storage unit that stores in advance data of a plurality of pattern images having different projection ranges from each other in the inspection device, and the secondary reflective object is present in the field of view of the imaging device. Selecting a pattern image that includes the secondary reflective object in the projection range but does not include the reflective surface in the projection range from the plurality of pattern images stored in the pattern image storage unit; It is preferable to change the pattern image to be selected into the selected pattern image. By preparing data of the pattern image in advance, it is possible to simplify the switching process of the pattern image (as compared to generating the pattern image each time).

For example, in the case where there is a secondary reflective object at the center of the field of view and in the case where there is a secondary reflective object at the edge of the field of view, the projection range of the pattern image must be changed. However, if separate pattern images are prepared for each position in the field of view, the number of pattern images becomes enormous. In addition, it is necessary to secure a large storage capacity in the pattern image storage unit, which leads to an increase in the cost of the apparatus. Therefore, the control device changes the position of the secondary reflective object in the field of view of the imaging device so that the secondary reflective object comes to a predetermined position in the field of view of the imaging device, and then the projection range changes. It intends line control for imaging the secondary reflection object by the image pickup device pattern image in a state projected to be. As described above, when the secondary reflective object is set to a predetermined position in the field of view, it is sufficient to prepare pattern images of different sizes and different shapes, and it is not necessary to prepare pattern images of different positions. In other words, the same pattern image can be commonly used for secondary reflective objects having substantially the same size and shape. Therefore, the number of pattern images prepared in advance can be significantly reduced, and the storage capacity of the pattern image storage unit can also be reduced. This configuration is particularly effective when the number of pattern images that can be registered in advance in the projection apparatus is limited.

Wherein the predetermined position is Ru center der of the field of view of the imaging device. The center of the field of view of the imaging device has the smallest aberration of the optical system of the imaging device. In addition, since the projection center of the projection device is usually aligned with the center of the field of view of the imaging device, distortion of the projection pattern (distortion due to aberration of the optical system of the projection device) is also minimized at the center of the field of view of the imaging device. Therefore, the accuracy of measurement and inspection can be expected to be further improved by projecting and imaging the secondary reflective object with the center of the field of view of the imaging device.

  When the secondary reflective object is present in the field of view of the imaging device, the control device sets the secondary reflective object within the projection range based on the information on the position and size of the secondary reflective object or the reflective surface. It is preferable to generate a pattern image that includes the reflection surface but does not include the reflective surface, and changes the pattern image projected from the projection apparatus to the generated pattern image. According to this configuration, an optimal projection range can be realized according to the position and size of the secondary reflecting object and the reflecting surface, and improvement in the accuracy of measurement and inspection can be expected. In addition, since it is not necessary to physically move the secondary reflective object or the imaging field, the processing time can be shortened.

  The inspection apparatus can be preferably applied to a substrate inspection apparatus that inspects components on a substrate. In this case, for example, an object such as a chip part or an IC is an object of inspection. According to the present invention, even if a cause object of secondary reflection (for example, a tall object such as a connector part) is present around a part to be inspected, generation of secondary reflection noise is suppressed to ensure reliability. It enables high part measurement and part inspection.

  The present invention can be grasped as an inspection apparatus or a substrate inspection apparatus including at least a part of the above means or functions. Further, the present invention is regarded as an inspection system having an inspection apparatus or substrate inspection apparatus including at least a part of the above means or functions, and a teaching apparatus for creating an inspection program for defining the operation of the inspection apparatus or substrate inspection apparatus. It can also be done. Further, the present invention can be regarded as a control method and inspection method of an inspection apparatus, a computer program for causing a computer to execute each step of the method, and a computer readable storage medium storing the program non-temporarily. You can also. Each of the above configurations and processes can be combined with each other as long as there is no technical contradiction.

  According to the present invention, in an inspection apparatus that inspects an object using an image captured in a state where a pattern image is projected onto the object, secondary reflection noise is suppressed, and highly reliable measurement and inspection are performed. it can.

The schematic diagram which shows the hardware constitutions of a board | substrate test | inspection system. The flowchart which shows the flow of teaching processing. 3 is a flowchart showing the flow of measurement and inspection in the first embodiment. The figure which shows the flow of the measurement in 1st Embodiment, and a test | inspection. The example of the pattern image in 1st Embodiment. The flowchart which shows the flow of measurement and inspection in a 2nd embodiment. The figure which shows the flow of the measurement in 2nd Embodiment, and a test | inspection. The flowchart which shows the flow of measurement and inspection in a 3rd embodiment. The figure which shows the flow of the measurement in 3rd Embodiment, and a test | inspection. The flowchart which shows the flow of measurement and inspection in a 4th embodiment. The figure which shows the flow of the measurement in 4th Embodiment, and a test | inspection. The figure explaining secondary reflective noise. The example of the phase image imaged by projecting a pattern image.

The present invention is a technique for suppressing secondary reflection noise and realizing highly reliable measurement and inspection in an inspection apparatus which inspects the object using an image captured in a state where a pattern image is projected onto the object. About. The present invention can be applied to an inspection apparatus using three-dimensional measurement by active triangulation or active stereo method, and in particular, can be preferably applied to an inspection apparatus used in the field of FA (factory automation) or automotive field. As inspections in the FA field, visual inspection, character inspection, positioning inspection, defective product inspection and the like using an image sensor (three-dimensional robot vision, three-dimensional digitizer, industrial image sensor, etc.) can be exemplified. Further, as inspection in the field of automobiles, tire shape inspection using a shape measurement sensor can be exemplified.

  Hereinafter, an example in which the present invention is applied to a substrate inspection apparatus in the FA field will be described in detail as a preferred embodiment for carrying out the present invention. However, the configurations and operations of the devices described in the following embodiments are merely examples, and the scope of the present invention is not limited thereto.

First Embodiment
(Hardware configuration of board inspection system)
An overall configuration of a substrate inspection system according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic view showing a hardware configuration of a substrate inspection system. The substrate inspection system includes a substrate inspection apparatus 1 that inspects the state of components and solder on a printed substrate using a captured image, and a teaching apparatus 2 that creates an inspection program that the substrate inspection apparatus 1 uses at the time of inspection. The substrate inspection apparatus 1 is preferably used for substrate appearance inspection (for example, component floating inspection after reflow) in a surface mounting line.

  The substrate inspection apparatus 1 mainly includes a stage 10, a measurement unit 11, a control device 12, an information processing device 13, a display device 14, and a storage device (database) 3. The measurement unit 11 includes an imaging device (image sensor) 110, a lighting device 111, and a projection device (projector) 112.

  The stage 10 is a mechanism for holding the substrate 15 and aligning the component 150 and the solder 151 to be inspected with the field of view of the imaging device 110. As shown in FIG. 1, when the X axis and the Y axis are parallel to the stage 10 and the Z axis is vertical to the stage 10, the stage 10 can translate at least two axes in the X direction and the Y direction. The imaging device 110 is disposed such that the optical axis is parallel to the Z axis, and images the substrate 15 on the stage 10 from above from above. The image data captured by the imaging device 110 is taken into the information processing device 13.

  The illumination device 111 (111R, 111G, 111B) is illumination means for illuminating the substrate 15 with illumination light (red light RL, green light GL, blue light BL) of different colors (wavelengths). FIG. 1 schematically shows the XZ cross section of the illumination device 111. In fact, the illumination device 111 has an annular shape so as to be able to illuminate light of the same color from all directions (all directions around the Z axis). Or it has a dome shape. The projection device 112 is a pattern projection unit that projects a pattern image PL having a predetermined pattern on the substrate 15. The projection device 112 projects the pattern image PL through an opening provided in the middle of the illumination device 111. Although the number of projection devices 112 may be one, it is preferable to provide a plurality of projection devices 112 in order to eliminate blind spots in the pattern image PL. In this embodiment, two projection devices 112 are arranged in different azimuths (diagonal positions). As the projection device 112, a DLP (Digital Light Processing) projector of a system using a digital mirror device can be preferably used. This is because the DLP projector can change the projection pattern. The illumination device 111 and the projection device 112 are both illumination systems used when photographing the substrate 15 by the imaging device 110, but the illumination device 111 is illumination used for shape measurement by color highlight illumination method, and the projection device An illumination 112 is used for shape measurement by active triangulation.

The control device 12 is a control unit that controls the operation of the substrate inspection device 1 and controls movement of the stage 10, lighting control of the lighting device 111, lighting control of the projection device 112, change of pattern and light amount, imaging of the imaging device 110 It is responsible for control and the like.

  The information processing apparatus 13 acquires various measurement values of the component 150 and the solder 151 by using the image data taken from the imaging apparatus 110, or solders the electrode of the component 150 and a land (pad) on a substrate. It is an apparatus having a function to check the status. The display device 14 is a device that displays the measurement value and the inspection result obtained by the information processing device 13. The storage device 3 is a database in which an inspection program used in the substrate inspection apparatus 1 and data (image, measurement result, inspection result, etc.) obtained by the substrate inspection apparatus 1 and the like are stored. The inspection program is software that defines the operation of the substrate inspection apparatus 1 and includes various computer programs executed by the control device 12 and the information processing device 13 and various parameter data used by those computer programs. It is. The parameter data of the inspection program includes, for example, information (part number, position, size, etc.) of parts present on the substrate, imaging conditions (set values of the illumination device 111 and the projection device 112, etc.), inspection area (field of view) and imaging The order of execution, the inspection item for each part, the determination reference value (such as a threshold value or a value range for determining pass / fail), and the like are defined. Further, in the parameter data of the inspection program, information specifying a part (secondary reflecting object) affected by the secondary reflection noise, information on an imaging condition when imaging the part, and the like are also defined. Prior to the inspection, the inspection program is created by the teaching device 2 and registered in the storage device 3 (this work is called teaching).

  Each of the control device 12 and the information processing device 13 includes, for example, a general-purpose computer having a CPU (central processing unit), a memory, an auxiliary storage device (such as a hard disk drive), and an input device (a keyboard, a mouse, a touch panel or the like). can do. The teaching device 2 can also be configured by, for example, a general-purpose computer having a CPU, a memory, an auxiliary storage device, and an input device. Although FIG. 1 shows the control device 12, the information processing device 13, the display device 14, the teaching device 2 and the storage device 3 in separate blocks, they may be configured as separate devices, You may comprise by one apparatus.

(Phase shift method)
Active triangulation methods are roughly classified into time coding method and space coding method, and light coding method and phase shift method are used as time coding method. In this embodiment, a phase shift method will be described as an example.

  The phase shift method is one of the methods of measuring three-dimensional information (height information) of the object surface by analyzing distortion of the pattern when the pattern image is projected on the object surface. Specifically, using the projection device 112, imaging is performed by the imaging device 110 in a state where a predetermined pattern (for example, a stripe pattern in which the luminance changes in a sine wave shape) is projected onto the substrate. Then, as shown in FIG. 13, the distortion of the pattern corresponding to the unevenness appears on the surface of the object. By repeating this process a plurality of times (for example, 4 times) while changing the phase of the luminance change of the pattern image, a plurality of images (hereinafter referred to as phase images) having different luminance features can be obtained as shown in FIG. Be Since the brightness (brightness) of the same pixel of each image should change with the same cycle as the change of the stripe pattern, the phase of each pixel can be obtained by applying a sine wave to the change of the brightness of each pixel. I understand. Then, the distance (height) from the reference position can be calculated by obtaining the phase difference with respect to the phase of the predetermined reference position (table surface, substrate surface, etc.).

As described above, in the phase shift method, the height of the object surface is estimated based on the periodic change in luminance among a plurality of images. Therefore, when the secondary reflection noise as described in FIG. 12 occurs, it is difficult to accurately detect the phase of the stripe pattern, which results in a decrease in measurement accuracy. Therefore, in the substrate inspection apparatus 1 according to the present embodiment, when there is a component (secondary reflective object) which may be affected by secondary reflection noise in the field of view of the imaging device, the projection range of the pattern image is selected. By limiting, light does not strike the component (causing object) that causes secondary reflection noise. This suppresses the occurrence of secondary reflection noise and prevents the decrease in measurement accuracy.

  In the following, (1) teaching processing and (2) processing of measurement and inspection based on phase shift will be specifically described as processing relating to measures against secondary reflection noise. In addition, although measurement and inspection using a color highlight illumination method are also performed in the substrate inspection system of the present embodiment, a publicly known method can be used for them, and the description thereof will be omitted. In addition, before the teaching process (for example, at the time of manufacture or installation of the substrate inspection apparatus 1), adjustment of the visual field position of the imaging device 110 and adjustment of focus, writing of a pattern image to the memory of the projection device 112, projection It is assumed that the adjustment of the resolution, focus, light quantity, and projection position of the apparatus 112, the setting of the normal (standard) imaging conditions, and the like are performed.

(1) Teaching FIG. 2 is a flowchart showing a flow of teaching processing.

  When a sample substrate for teaching is set on the stage 10 of the substrate inspection apparatus 1 and an instruction to start teaching processing (inspection program creation start) is input to the teaching apparatus 2, the processing of FIG. 2 is started. As the sample substrate, it is preferable to use a non-defective substrate on which all parts to be inspected and the like are mounted in a correct state. This is to register the height and position of the correct answer of each inspection target object in the inspection program. Moreover, it is for detecting components which may generate secondary reflection noise without omission.

  In step S200, the control device 12 controls the stage 10 to move the inspection area on the sample substrate into the field of view of the imaging device 110. In step S201, the control device 12 turns on the illumination device 111 entirely (or projects uniform white light without a pattern from the projection device 112), and causes the imaging device 110 to capture (here, the image acquired No image called "). Next, in step S202, the control device 12 causes the projection device 112 to project a pattern image of a stripe pattern, and causes the imaging device 110 to capture a phase image. At this time, a plurality of (for example, four) phase images are captured while changing the phase of the stripe pattern. The pattern-free image and the phase image obtained in step S201 and step S202 are taken into the teaching device 2.

  The teaching device 2 sets an inspection window for each of the plurality of inspection target objects present on the substrate (step S203). The inspection window is information for specifying the position and size of the inspection target object, and is defined by, for example, a circumscribed rectangle of the inspection target object. The setting of the inspection window may be set automatically with reference to the CAD information of the substrate, or may be set manually by the operator. In the case of the manual setting, it is easy to operate by displaying the patternless image of the substrate on the screen and making it possible to designate the area of the inspection window on the image using a mouse or the like. Although the typical inspection object is a component, an object other than the component (for example, a part of a component such as an electrode, land, solder, wiring, etc.) may be set as the inspection object. Thereafter, the teaching device 2 sets inspection parameters (inspection items, determination reference values, etc.) for each inspection target object (step S204). The setting of the inspection parameter is the same as the conventional teaching, so the description will be omitted.

Subsequently, teaching for suppressing secondary reflection is performed. First, in step S205, it is determined whether or not there is a secondary reflecting object among a plurality of inspection target objects for which an inspection window has been set, and a process of adding a flag to the detected secondary reflecting object is performed. The processing in step S205 may be processing that the teaching device 2 automatically detects and sets, or processing that an operator visually detects and sets manually. As a method of automatic detection, a method of evaluating the reliability, sharpness, and luminance of the projection pattern in the phase image acquired in step S202, a method of evaluating variation in height information calculated from the phase image, and the like It can be used. Alternatively, the height and positional relationship of each object is acquired from the CAD information of the substrate, and the secondary reflection object is detected by geometrical calculation based on the incident angle of the projection pattern, the height of the object, and the distance between the objects. It can also be done. On the other hand, in the case of manual setting, a patternless image of the substrate may be displayed on the screen, and a secondary reflective object may be selected on the screen using a mouse or the like.

  Subsequently, the teaching device 2 sets an imaging condition for secondary reflection suppression with respect to the secondary reflective object to which the flag is attached (step S206; YES) (step S207). In this embodiment, at the time of inspection, the processing of “move the secondary reflective object to the center of the field of view of the imaging device 110 and project and capture the pattern image only on the area including the secondary reflective object” is performed. As at least, a condition that defines a view position when imaging a secondary reflective object, and a condition that defines a projection range (or projection size) of a pattern image are set. When a plurality of secondary reflection objects are present in the image, imaging conditions for secondary reflection suppression may be set individually for each secondary reflection object, or a plurality of secondary reflections adjacent to each other may be set. Objects may be set as one group, and imaging conditions for secondary reflection suppression may be set in group units.

  Above, teaching to the inspection area set up at Step S200 is completed. If the size of the substrate is larger than the field of view of the imaging device 110, the inspection area is changed and the processing of steps S200 to S207 is repeated (step S208). For example, when the size of the substrate is 210 mm × 210 mm and the field of view of the imaging device 110 is 30 mm × 30 mm, teaching is performed on a 7 × 7 = 49 inspection area. Finally, the teaching device 2 stores the inspection program in the storage device 3, and the process ends (step S209). In addition, after setting for all objects to be inspected on the substrate is completed, the position of the inspection area at the time of inspection and the scan order thereof are optimized so as to minimize the number of imaging times at the time of inspection and the moving distance of the stage 10. You may process.

(2) Measurement and Inspection Based on Phase Shift An example of inspection processing in the substrate inspection apparatus 1 will be described with reference to the flowchart in FIG. FIG. 3 shows the flow of measurement and inspection based on phase shift in the first embodiment. These processes are implemented by the information processing device 13 and the control device 12 controlling the stage 10, the imaging device 110, the illumination device 111, and the projection device 112 according to the inspection program.

  When the substrate to be inspected is carried onto the stage 10, the controller 12 adjusts the position of the substrate based on the fiducial marks on the substrate (step S300), and then the imaging device 110 is used to scan the first inspection area. (Step S301). (1) of FIG. 4 schematically shows the substrate in the field of view 41. In this example, two chip parts 42 a, 42 b and a tall connector part 43 are included in the field of view 41.

  First, in order to image the entire visual field (inspection area) 41, the control device 12 sets the projection pattern of the projection device 112 to the "normal pattern image" (step S302). The normal pattern image is an image for projecting a stripe pattern on substantially the entire field of view 41 of the imaging device 110. (2) of FIG. 4 is an example of the state of the field of view when the normal pattern image is projected.

FIG. 5 schematically shows types of pattern images that can be projected from the projection device 112. In this embodiment, in addition to the normal pattern image 51, a total of six types of data of five types of secondary reflection suppression pattern images 52 to 56 of different sizes are included in the memory (pattern image storage unit) 50 of the projection device 112. It is stored. The secondary reflection suppression pattern images 52, 53, 54, 55, 56 respectively have striped patterns in the range of 2 mm × 2 mm, 4 mm × 4 mm, 6 mm × 6 mm, 8 mm × 8 mm, 10 mm × 10 mm at the center of the visual field 41 It is an image for projection. That is, the secondary reflection suppression pattern images 52 to 56 are images in which the projection range of the pattern image is limited to a part of the field of view 41. Although only one image is shown for each projection size in FIG. 5, actually, a plurality of (for example, four) images having different phases are prepared for each projection size. Further, in order to expand the measurement range, an image in which the pattern cycle is changed may be prepared.

  In step S303, the control device 12 causes the imaging device 110 to capture an image while switching the phase of the normal pattern image 51 projected from the projection device 112. Thereby, a plurality of phase images are obtained (the phase image acquired in step S303 is referred to as a "normal phase image"). Data of the acquired phase image is taken into the information processing device 13. In step S304, the information processing device 13 calculates the height of each pixel by analyzing the phase of the luminance change of each pixel using the normal phase image data obtained in step S303. The calculated height information is stored in the form of image data (referred to as height data) in which the height (Z position) from the substrate surface is represented by pixel values. (3) of FIG. 4 shows an example of height data. The substrate surface is shown in black (pixel value: 0), and becomes brighter (pixel value becomes larger) as the height from the substrate surface becomes larger.

  Next, the control device 12 refers to the inspection program and determines whether or not there is an inspection target object with a flag of a secondary reflective object in the current visual field 41 (step S305). If there is a secondary reflective object, the control device 12 moves the secondary reflective object to the center of the field of view of the imaging device 110 according to the imaging condition for secondary reflection suppression in the inspection program (step S306), and the projection device The projection pattern 112 is changed to an appropriate "secondary reflection suppression pattern image" (step S307).

  For example, it is assumed that the right side surface of the connector component 43 is a reflection surface, light from the projection device 112 is reflected by the top surface of the chip component 42a, and secondary reflection noise is generated in the chip component 42a. In that case, as shown in (4) of FIG. 4, the chip component 42a is moved so that the center of the chip component 42a coincides with the center of the visual field 41, and as shown in (5) of FIG. Limit the projection range so that only striped patterns hit. If the size of the chip component 42a is, for example, 2 mm × 5 mm, any one of the secondary reflection suppression pattern images 54 to 56 having a projection size larger than the component size is used. However, the stripe pattern does not hit the reflection surface (right side surface) of the connector part 43 which is the cause of the secondary reflection noise.

  Then, in step S308, the control device 12 causes the imaging device 110 to capture images while switching the phase of the secondary reflection suppression pattern image projected from the projection device 112, and acquires a plurality of phase images (acquired in step S308) The phase image is called "secondary reflection suppression phase image"). The acquired phase image data is taken into the information processing device 13. In step S309, the information processing device 13 performs processing similar to that in step S304 using the secondary reflection suppression phase image data obtained in step S308 to generate height data of a portion of the secondary reflective object. At this time, information lacking in the secondary reflection suppression phase image data (for example, height information of the substrate surface, height information around the secondary reflective object, etc.) usually uses information extracted from the phase image data. It is good to do. When there are other secondary reflective objects in the field of view 41, the processing of steps S306 to S309 is repeated, and height data of each secondary reflective object is acquired. (6) of FIG. 4 is an example of height data of the secondary reflective object.

  In step S310, the information processing device 13 combines the height data of the entire visual field generated in step S304 with the height data of the secondary reflective object generated in step S309. As a synthesizing method, a method of replacing the data of the corresponding part in the height data of the whole visual field with the height data of the secondary reflecting object, the data of the corresponding part in the height data of the whole visual field and the height of the secondary reflecting object Any image combining method may be used, such as a method of determining an average or weighted average of data. Thereby, as shown to (7) of FIG. 4, the height data by which secondary reflection noise was suppressed can be obtained.

  After executing the processing of steps S301 to S310 on all inspection areas on the substrate (step S311), the information processing apparatus 13 uses the height data after composition obtained in step S310 to execute each inspection object object Inspection (for example, component floating, solder fillet failure, etc.), and the result is output (step S312). Thus, the measurement and inspection process for one substrate is completed.

(Advantages of the present embodiment)
According to the configuration of the present embodiment, when there is a secondary reflective object (for example: chip component 42a) in the field of view 41 of the imaging device 110, the cause object (for example: connector component 43) that causes secondary reflection The projection range of the pattern image is changed so that light does not hit the reflective surface of. Therefore, the generation of secondary reflection noise can be suppressed, and the projection pattern on the inspection target object can be accurately imaged (observed), and the accuracy of measurement and inspection of the inspection target object can be improved.

  Further, in the present embodiment, since data of a plurality of types of pattern images are prepared in advance in the pattern image storage unit 50 of the projection device 112, switching of pattern images (compared to generation of a pattern image each time) Processing can be simplified.

  Furthermore, since the secondary reflection object is moved to the center of the field of view to perform imaging for secondary reflection suppression, the same secondary reflection suppression pattern image can be commonly used for objects of substantially the same size and shape, and prepared in advance. The number of pattern images to be stored can be significantly reduced. Usually, the storage capacity of the pattern image storage unit (memory) 50 built in the projection device 112 is limited, so that the number of pattern images (data capacity) can be reduced, which is a great practical advantage. Moreover, since the visual field center has the smallest aberration of the optical system of the imaging device 110 and the smallest distortion of the projection pattern (the distortion due to the aberration of the optical system of the projection device 112), the accuracy of measurement and inspection is further improved. Can be expected.

  In the present embodiment, the secondary reflective object is moved to the center of the visual field, but the scope of the present invention is not limited to this. After projection and imaging are performed after moving the secondary reflective object so that the secondary reflective object comes to a predetermined position in the field of view of the imaging device 110, at least suppression of secondary reflective noise, switching of the pattern image The effects of simplification of processing and commonality of pattern images can be obtained.

Second Embodiment
Next, a second embodiment of the present invention will be described. In the first embodiment, while the secondary reflective object is moved to the center of the field of view and imaged, in the second embodiment, the position of the secondary reflective object and the position of the secondary reflective object are not changed. It is characterized in that a pattern image having an appropriate projection range is generated and projected according to the size. The basic configuration of the substrate inspection system is the same as that of the first embodiment, and therefore, the configuration and operation specific to this embodiment will be mainly described below.

  The flow of measurement and inspection based on phase shift in the second embodiment will be described with reference to FIGS. 6 and 7. FIG. 6 is a flowchart showing the flow of measurement and inspection, and FIG. 7 is a schematic view showing the flow of measurement and inspection.

  First, as in the first embodiment, the entire field of view is imaged using the normal pattern image, and height data of the entire field of view is calculated based on the normal phase image (steps S300 to S304 in FIG. )-(3)).

Thereafter, the control device 12 refers to the inspection program and determines whether or not there is an inspection target object with the flag of the secondary reflection object present in the current visual field 41 (step S305).
If there is a secondary reflection object, the control device 12 generates a secondary reflection suppression pattern image used for imaging the secondary reflection object according to the imaging condition for secondary reflection suppression in the inspection program (step S600). . Information on the position and size of the secondary reflective object (for example, a rectangle including secondary reflective objects (a plurality of neighboring secondary reflective objects are imaged together as one group) as imaging conditions for secondary reflection suppression In this case, the coordinate values of the upper left point and the lower right point of the rectangle including the plurality of secondary reflective objects belonging to the group are given. Then, the control device 12 writes the data of the generated secondary reflection suppression pattern image into the memory of the projection device 112, and changes the projection pattern of the projection device 112 (step S601). The subsequent processing (steps S308 to S312) is the same as the processing of the first embodiment.

  According to the configuration of the present embodiment, as shown in (4) of FIG. 7, the position within the field of view of the chip component 42a remains unchanged, and the secondary reflective object (chip component 42a) is included in the projection range. In the reflection surface of the part 43), a secondary reflection suppression pattern image which is out of the projection range is automatically generated and projected. Therefore, the generation of secondary reflection noise can be suppressed, and the projection pattern on the inspection target object can be accurately imaged (observed), and the accuracy of measurement and inspection of the inspection target object can be improved.

  Further, in the present embodiment, since an optimum projection range can be realized according to the position and size of the secondary reflective object, generation of noise can be suppressed as much as possible, and further improvement in the accuracy of measurement and inspection can be expected. . Moreover, since it is not necessary to change the position within the field of view of the secondary reflective object, physical drive such as stage movement can be reduced, and processing time can be shortened.

  In the present embodiment, the secondary reflection suppression pattern image is generated at the inspection time, but the secondary reflection suppression pattern image for each secondary reflection object may be generated and stored in advance at the time of teaching. If the pattern image storage unit (memory) in the projection device 112 has a sufficient storage capacity, data of all pattern images may be written in the projection device 112 in advance. If the storage capacity of the projection device 112 is not sufficient, data of the pattern image is stored in the pattern image storage unit in the storage device 3 or in the auxiliary storage device of the information processing device 13, and the pattern image required when necessary. The controller 12 may read and use the data of.

Third Embodiment
Next, a third embodiment of the present invention will be described. When there is a secondary reflective object in the field of view, in the first and second embodiments, imaging of the entire field of view using a normal pattern image and imaging of a secondary reflective object using a secondary reflection suppression pattern image Was done. On the other hand, the third embodiment is characterized in that the entire field of view is imaged using a secondary reflection suppression pattern image having a projection range such that light does not hit the reflection surface of the cause object instead of the normal pattern image. There is. The basic configuration of the substrate inspection system is the same as that of the first embodiment, and therefore, the configuration and operation specific to this embodiment will be mainly described below.

  The flow of measurement and inspection based on phase shift in the third embodiment will be described with reference to FIGS. 8 and 9. FIG. 8 is a flowchart showing the flow of measurement and inspection, and FIG. 9 is a schematic view showing the flow of measurement and inspection.

  First, as in the first embodiment, a substrate to be inspected is carried in, and the first inspection area is adjusted to the field of view of the imaging device 110 (steps S300 to S301 in FIG. 8, (1) in FIG. 9). The control device 12 refers to the inspection program and determines whether or not there is an inspection target object with the flag of the secondary reflective object in the current visual field 41 (step S800). When there is no secondary reflective object (step S800; NO), the control device 12 sets the projection pattern of the projection device 112 as a normal pattern image (step S801).

  On the other hand, when there is a secondary reflection object (step S800; YES), the control device 12 generates a secondary reflection suppression pattern image based on the imaging condition for secondary reflection suppression in the inspection program (step S802). . In the present embodiment, information on the position and size of the reflective surface of the connector part 43 which is the cause object (for example, a rectangle to be excluded from the projection range in order not to apply light to the reflective surface) as imaging conditions for secondary reflection suppression The coordinate values of the upper left and lower right points of the region are given. In addition, as the secondary reflection suppression pattern image, as shown in (2) of FIG. 9, it has a projection range excluding a portion 90 including the reflection surface of the cause object (connector part 43) from the projection range of the normal pattern image. An image is generated. The control device 12 writes the data of the generated secondary reflection suppression pattern image in the memory of the projection device 112, and sets the projection pattern of the projection device 112 as a secondary reflection suppression pattern image (step S803).

  Thereafter, imaging of a phase image is performed using the pattern image set in step S801 or S803 (step S804), and height data is calculated by the information processing apparatus 13 (step S805). The subsequent processing (steps S311 to S312) is the same as the processing of the first embodiment.

  According to the configuration of the present embodiment, as shown in (2) of FIG. 9, when there is a secondary reflective object (chip component 42a) in the field of view 41, light does not strike the portion 90 including the reflective surface. The secondary reflection suppression pattern image with various projection range is automatically generated and projected. Therefore, the generation of secondary reflection noise can be suppressed, and the projection pattern on the inspection target object can be accurately imaged (observed), and the accuracy of measurement and inspection of the inspection target object can be improved.

  Further, in the present embodiment, since the pattern image is projected on the area other than the reflective surface, the projection range of the pattern image can be maximized. As a result, the number of objects that can be measured in one projection and imaging can be increased as much as possible (for example, in the example of FIGS. 9 (2) and (3), the number of objects in the field of view in one projection and imaging) The height data of all objects can be acquired.) The number of imaging times can be reduced and the processing time can be shortened as compared with the first and second embodiments.

  In the present embodiment, the secondary reflection suppression pattern image is generated at the inspection time, but the secondary reflection suppression pattern image for each inspection area may be generated and stored in advance at the time of teaching. If the pattern image storage unit (memory) in the projection device 112 has a sufficient storage capacity, data of all pattern images may be written in the projection device 112 in advance. If the storage capacity of the projection device 112 is not sufficient, data of the pattern image is stored in the pattern image storage unit in the storage device 3 or in the auxiliary storage device of the information processing device 13, and the pattern image required when necessary. The controller 12 may read and use the data of.

Fourth Embodiment
Next, a fourth embodiment of the present invention will be described. In the first to third embodiments, the projection range of the pattern image is changed to suppress the secondary reflection noise when there is a secondary reflection object in the field of view, whereas in the fourth embodiment, the projection of the pattern image is performed. It is characterized in that secondary reflection noise is suppressed by resetting the position. The basic configuration of the substrate inspection system is the same as that of the first embodiment, and therefore, the configuration and operation specific to this embodiment will be mainly described below.

  The flow of measurement and inspection based on phase shift in the fourth embodiment will be described with reference to FIGS. 10 and 11. FIG. 10 is a flowchart showing the flow of measurement and inspection, and FIG. 11 is a schematic view showing the flow of measurement and inspection.

  First, as in the first embodiment, the entire field of view is imaged using the normal pattern image, and height data of the entire field of view is calculated based on the normal phase image (steps S300 to S304 in FIG. 10; )-(3)).

  Thereafter, the control device 12 refers to the inspection program and determines whether or not there is an inspection target object with the flag of the secondary reflection object present in the current visual field 41 (step S305). When there is a secondary reflective object, the control device 12 controls the stage 10 according to the imaging condition for secondary reflection suppression in the inspection program, and moves the secondary reflective object to a position where secondary reflection does not occur. (Step S1000). Specifically, as shown in (4) of FIG. 11, although the secondary reflective object (chip component 42a) is included in the projection range, the reflective surface of the cause object (connector component 43) that causes secondary reflection Resets the projection position of the pattern image so as to be out of the projection range. In the present embodiment, since the field of view 41 of the imaging device 110 substantially matches the projection range of the pattern image and the two move together, the “projected position of the pattern image” can be reworded as “field of view position”. . At this time, information of a visual field position at the time of imaging a secondary reflective object is given as an imaging condition for secondary reflection suppression. After resetting the projection position of the pattern image, as shown in (5) of FIG. 11, the control device 12 projects a normal pattern image from the projection device 112 and captures a phase image of the secondary reflection object (step S1001). The subsequent processing (steps S309 to S312 and (6) to (7) in FIG. 11) is the same as the processing of the first embodiment.

  According to the configuration of the present embodiment, when there is a secondary reflective object (for example: chip component 42a) in the field of view 41 of the imaging device 110, the cause object (for example: connector component 43) that causes secondary reflection The projection position (field of view position) of the pattern image is changed so that light does not hit the reflection surface of Therefore, the generation of secondary reflection noise can be suppressed, and the projection pattern on the inspection target object can be accurately imaged (observed), and the accuracy of measurement and inspection of the inspection target object can be improved.

  Further, in the present embodiment, since it is not necessary to change the pattern image as in the first to third embodiments, a projection device with a small storage capacity of the pattern image storage unit or a projection device of a type in which the pattern image can not be changed is used. It also has the advantage of being able to

Other Embodiments
The above description of the embodiment merely exemplifies the present invention, and the present invention is not limited to the above specific form. The present invention can be modified in various ways within the scope of the technical idea. For example, although the phase shift method is used in the above embodiment, the present invention is preferably applied to methods other than the phase shift method as long as the method includes the step of imaging an object in a state where a pattern image is projected. Can. Further, although the example in which the present invention is applied to substrate inspection has been described in the above embodiment, the scope of application of the present invention is not limited to this. For example, the present invention can be preferably applied to inspection devices used in the FA field and automotive field .

1: Substrate inspection device 2: 2: Teaching device 3: Storage device 10: Stage 11: Measurement unit 12: Control device 13: Information processing device 14: Display device 15: Substrate 41: Field of view 42a, 42b : Chip part, 43: connector part 50: pattern image storage part, 51: normal pattern image, 52 to 56: secondary reflection suppression pattern image 90: part 110 including the reflection surface of reflective part 110: imaging device, 111: illumination device , 111B: blue light source, 111G: green light source, 111R: red light source, 112: projection device 150: parts, 151: solder 200: imaging device, 201: projector, 201L: pattern light, 201R: primary reflected light, 202: Object, 203: tall object, 203L: reflected light, 203R: secondary reflected light RL: red light, BL: blue light, GL: green light, L: pattern image

Claims (10)

An imaging device,
A projection device for projecting a pattern image within the field of view of the imaging device;
An information processing apparatus for inspecting one or more objects included in a field of view of the imaging device using an image captured by the imaging device in a state in which a pattern image is projected from the projection device;
A control device that controls the imaging device and the projection device;
In the field of view of the imaging device, if there is a secondary reflective object that can cause secondary reflection due to light reflected by the reflective surface of another object,
The control device changes the position of the secondary reflective object in the field of view of the imaging device so that the secondary reflective object is at a central position in the field of view of the imaging device, and then light is transmitted to the reflective surface. The secondary reflective object is changed by the imaging device in a state where the projection range of the pattern image projected from the projection device is changed to a predetermined range at the center of the visual field so that the projection image does not hit, and the pattern image whose projection range is changed is projected. An inspection apparatus that performs control of imaging an image. And a storage device for storing an inspection program including information for identifying a secondary reflective object from among a plurality of objects to be inspected.
The inspection apparatus according to claim 1, wherein the control device determines whether a secondary reflective object is present in a field of view of the imaging device based on the inspection program. The inspection program includes information of imaging conditions when imaging a secondary reflective object,
The inspection apparatus according to claim 2, wherein the control device changes a projection range of a pattern image to be projected when imaging the secondary reflective object, based on information of the imaging condition. The image processing apparatus further includes a pattern image storage unit that stores in advance data of a plurality of pattern images having different projection ranges.
When the secondary reflective object is present in the field of view of the imaging device,
The control device selects, from the plurality of pattern images stored in the pattern image storage unit, a pattern image that includes the secondary reflective object in the projection range but does not include the reflective surface in the projection range. The inspection apparatus according to any one of claims 1 to 3, wherein a pattern image projected from a projection device is changed to the selected pattern image. When the secondary reflective object is present in the field of view of the imaging device,
The control device generates a pattern image that includes the secondary reflective object in the projection range but does not include the reflective surface in the projection range, based on the information of the position and size of the secondary reflective object or the reflective surface. The inspection apparatus according to any one of claims 1 to 3, wherein a pattern image projected from a projection device is changed to the generated pattern image. The inspection apparatus according to any one of claims 1 to 5 , wherein the inspection apparatus is a substrate inspection apparatus that inspects a component on a substrate. An imaging device, a projection device for projecting a pattern image within the field of view of the imaging device, and an image captured by the imaging device in a state where the pattern image is projected from the projection device are used within the field of view of the imaging device An inspection apparatus including an information processing apparatus that inspects one or more included objects; and a control apparatus that controls the imaging apparatus and the projection apparatus.
A teaching apparatus for creating an inspection program that defines the operation of the inspection apparatus;
An inspection system having
The teaching apparatus includes information for identifying a secondary reflection object that may cause secondary reflection due to light reflected by a reflection surface of another object, and information of imaging conditions when imaging the secondary reflection object. Create an inspection program that includes
In the case where there is a secondary reflection object that can cause secondary reflection due to light reflected by a reflection surface of another object in the field of view of the imaging device, the control device determines that the secondary reflection object is the image After changing the position of the secondary reflective object in the field of view of the imaging device so as to come to the center position in the field of view of the device, the projection is performed so that light does not hit the reflective surface based on the inspection program. The projection range of the pattern image to be projected from the device is changed to a predetermined range at the center of the field of view, and control is performed to capture the secondary reflective object by the imaging device in a state where the pattern image whose projection range is changed is projected. An inspection system characterized by A control method of an inspection apparatus, comprising: an imaging device; and a projection device for projecting a pattern image into a field of view of the imaging device,
In the field of view of the imaging device, in the case where there is a secondary reflecting object that may cause secondary reflection due to light reflected by the reflecting surface of another object, the secondary reflecting object is in the field of view of the imaging device to come to the center position, after changing the position of the secondary reflection object in the field of view of the imaging device, the projection range of the pattern image projected from the projection device so as not exposed to light on the reflecting surface the field Changing to a predetermined range at the center of the
Imaging the secondary reflective object by the imaging device in a state where the pattern image whose projection range has been changed is projected;
And D. inspecting the secondary reflection object using the image captured by the imaging device. The inspection apparatus further includes a storage device for storing an inspection program including information for identifying a secondary reflective object from among a plurality of objects to be inspected.
9. The control method of the inspection apparatus according to claim 8 , wherein it is determined whether or not a secondary reflective object is present in the field of view of the imaging device based on the inspection program. The inspection program includes information of imaging conditions when imaging a secondary reflective object,
The control method of the inspection apparatus according to claim 9 , wherein a change of a projection range of a pattern image to be projected when imaging the secondary reflective object is performed based on the information of the imaging condition.

Images