JP2019124544A - Inspection device adjustment method and inspection device - Google Patents

Abstract

To provide an inspection device adjustment method and an inspection device including the adjustment method, with which it is possible to easily correct the right angle of an imaging unit drive mechanism by a simple configuration without requiring a special sensor, etc., for right angle correction.SOLUTION: Provided is an inspection device comprising an imaging unit 20, an XY stage 40 having an X direction guide 41, a Y direction master guide 43 and a Y direction slave guide 45, a reference board 47, and a control unit. The control unit includes the steps of: imaging three markers MA, MB, MC of the reference board 47 and detecting the position of the imaging unit 20; calculating the angles of the X direction guide 41, the Y direction master guide 43 and the Y direction slave guide 45 from the position of the imaging unit 20; and correcting the position of one end of the X direction guide 41 in the Y direction master guide 43 and the position of the other end of the X direction guide 41 in the Y direction slave guide 45 so that the angles are 90°.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method of adjusting an inspection apparatus and an inspection apparatus having the adjustment method.

  In recent years, electronic circuit boards have come to be mounted on various devices, but in devices on which this type of electronic circuit board is mounted, downsizing and thinning have always been an issue, From this point, it is required to increase the density of mounting of the electronic circuit board. For example, in an XY drive device for moving a camera for capturing an image of an electronic circuit board on which components are mounted in an electronic circuit board mounting device, relative to the electronic circuit board, an X-axis unit constituting the XY drive device If there is an error in the assembly of the Y and Y axis units, accurate mounting results can not be obtained.

  Conventionally, in an electronic circuit board mounting apparatus, it is important to correct an error in assembling the X-axis unit and the Y-axis unit in order to accurately mount electronic components on a predetermined position on the electronic circuit board. A method of measuring the distortion of the X-axis unit and the Y-axis unit by imaging the observation point on the reference jig and correcting the distortion of the machine coordinate system consisting of the X-axis unit and the Y-axis unit For example, Patent Document 1 discloses the disclosure.

Japanese Patent Application Publication No. 2003-028615

  However, in the conventional method, it is necessary to obtain in advance a correction parameter by the least squares method or the like from images of a plurality of observation points on the reference jig, and to correct using this parameter when operating the XY drive device. There is a problem that processing becomes complicated.

  Also, in the conventional inspection apparatus for electronic circuit boards, the absolute position on the substrate of the inspection object on the electronic circuit boards has not been emphasized, but in recent years, the mounting apparatus for electronic circuit boards and the inspection apparatus for electronic circuit boards It is advanced to link information on the subject under examination. It is important that the absolute position of each inspection object on the substrate be accurately grasped in order to link the information on the inspection object between the mounting device of the electronic circuit substrate and the inspection device of the electronic circuit substrate. Also in the inspection apparatus of the electronic circuit board, it is a problem to more accurately measure the absolute position on the board of the inspection object on the electronic circuit board.

  For that purpose, it is necessary to make the X-axis unit and Y-axis unit which comprise a coordinate system orthogonal.

  The present invention has been made in view of such problems, and it is possible to easily perform right angle correction of an imaging unit drive mechanism (XY drive device) with a simple configuration without requiring a special sensor or the like for right angle correction. It is an object of the present invention to provide a method of adjusting an inspection device that can perform the inspection and an inspection device having the adjustment method.

  In order to solve the problem, an adjustment method of an inspection apparatus according to the present invention includes an imaging unit for imaging an object to be inspected, a first guide for moving the imaging unit in a first direction, and one end of the first guide An imaging unit drive mechanism having a second guide moving the side in the second direction, and a third guide moving the other end side of the first guide in the second direction; Of the first guide, the second guide, and the third guide, which is detachable, and has an intersection point of two orthogonal straight lines and at least three markers disposed on each of the two straight lines; And a control unit for controlling operation, wherein the control unit unit images each of the three markers on the reference board with the imaging unit, and the imaging unit for each of the three markers is The steps of: detecting the position of the lens; calculating the angle between the first direction and the second direction from the position of the imaging unit; and setting the angle to approximately 90 °. And correcting the position of one end of the first guide in the second guide and the position of the other end of the first guide in the third guide.

  Further, in the adjustment method of the inspection apparatus according to the present invention, the step of calculating the angle includes: a straight line connecting the position of the sign at the intersection of the two straight lines and the position of the sign on one of the two straight lines; It is preferable to calculate the angle between the position of the mark on the straight line of intersection and the straight line connecting the position of the mark on the other of the two straight lines as the angle between the first direction and the second direction.

  Further, in the adjustment method of the inspection apparatus according to the present invention, the control unit is configured to control the position of the imaging unit, the position of one end of the first guide in the second guide, and the first guide in the third guide. The control unit is configured to determine the position of the imaging unit based on the design value and the correction value, the control unit having a design value that is a correspondence relationship with an end position, and a correction value of the design value. Preferably, in the correcting step, the correction value at which the angle is approximately 90 ° is calculated and stored.

  In the inspection apparatus according to the present invention, an imaging unit for imaging an object to be inspected, a first guide for moving the imaging unit in a first direction, and one end of the first guide are moved in a second direction. An imaging unit drive mechanism having a second guide and a third guide for moving the other end side of the first guide in the second direction, and removable and orthogonal to the position of the inspection object 2 A reference board having an intersection of straight lines and at least three markings arranged on each of the two straight lines; and a control unit for controlling the operation of the first guide, the second guide and the third guide And the controller unit controls the first guide of the second guide such that an angle between the first direction and the second direction is approximately 90.degree. According to the adjustment method of the inspection apparatus described above. The position of one end of the And correcting the position of the first guide and the other end of the serial third guide.

  According to the present invention, it is possible to provide an adjustment method of an inspection apparatus capable of easily performing right angle correction of an imaging unit drive mechanism with a simple configuration without requiring a special sensor or the like for right angle correction.

It is a block diagram showing composition of an inspection device. It is a schematic diagram which shows the structure of XY stage. It is explanatory drawing explaining the relationship between the phase of a reference plane, and the measured phase. It is a flowchart which shows the flow of a right angle correction process. It is explanatory drawing which shows the correction method of the angle in right angle correction processing.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. First, the configuration of the inspection apparatus 10 according to the present embodiment will be described using FIGS. 1 to 3. The inspection apparatus 10 is an apparatus that inspects the test object 12 using test object image data obtained by imaging the test object 12. The inspection object 12 is, for example, an electronic circuit board to which a solder is applied. The inspection apparatus 10 determines the quality of the application state of the solder based on the inspection object image data.

  The inspection apparatus 10 includes an inspection table 14 for holding the inspection object 12, an imaging unit 20 for illuminating and imaging the inspection object 12, and an XY stage 40 for moving the imaging unit 20 relative to the inspection table 14; And a control unit 30 for controlling the operations of the imaging unit 20 and the XY stage 40 and performing inspection of the inspection object 12. For convenience of explanation, as shown in FIG. 1, the inspection object disposition surface of the inspection table 14 is an XY plane, and the direction perpendicular to the disposition surface (ie, the imaging direction by the camera unit 21 configuring the imaging unit 20 (camera unit 21) is the Z direction.

  The imaging unit 20 is attached to a moving table (not shown) of the XY stage 40, which is a mechanism (imaging unit driving mechanism) for driving the imaging unit, and is moved by the XY stage 40 in each of the X and Y directions. It is movable. The XY stage 40 is, for example, a so-called H-type XY stage. Therefore, the XY stage 40 moves the movable table 41a in the X direction along the X direction guide 41 which is the first guide extending in the X direction which is the first direction, and the X direction guide 41 at both ends thereof Two Y direction guides and Y drive units (one of which is the second guide “Y as the second guide, which is supported by the movable table 41a and the X direction guide 41 can be moved in the Y direction which is the second direction. Direction master guide 43 "and" Y master drive unit 44 ", and the other is called a third guide" Y direction slave guide 45 "and" Y slave drive unit 46 ". The XY stage 40 may further include a Z movement mechanism for moving the imaging unit 20 in the Z direction, and may further include a rotation mechanism for rotating the imaging unit 20. The inspection apparatus 10 may further include an XY stage that allows the inspection table 14 to move. In this case, the XY stage 40 that moves the imaging unit 20 may be omitted. Further, a linear motor or a ball screw can be used for the X drive unit 42 and the Y drive units 44 and 46.

  The inspection apparatus 10 according to the present embodiment detects the position in the X-axis direction of the moving table 41a (imaging unit 20) in the X-direction guide 41 by the X-direction position detection unit 41b provided in the X-direction guide 41. The position of the X direction guide 41 in the Y direction master guide 43 is detected by the Y direction master position detection unit 43a provided in the Y direction master guide 43, and the Y direction slave position detection unit provided in the Y direction slave guide 45 By detecting at 45a, the positions of the imaging unit 20 in the X-axis direction and Y-axis direction are determined from the detection values of the X-direction position detection unit 41b, the Y-direction master position detection unit 43a, and the Y-direction slave position detection unit 45a. Are configured to

  The imaging unit 20 includes a camera unit 21 for capturing an image in a direction (Z-axis direction) perpendicular to the inspection surface (substrate surface) of the inspection object 12, an illumination unit 22, and a projection unit 23. . In the inspection apparatus 10 according to the present embodiment, the camera unit 21, the illumination unit 22, and the projection unit 23 may be configured as an integral imaging unit 20. In the integrated imaging unit 20, the relative positions of the camera unit 21, the illumination unit 22, and the projection unit 23 may be fixed, or each unit may be configured to be relatively movable. Also, the camera unit 21, the illumination unit 22, and the projection unit 23 may be separated and configured to be separately movable.

  The camera unit 21 includes an imaging device that generates a two-dimensional image of an object, and an optical system (for example, a lens) for forming an image on the imaging device. The camera unit 21 is, for example, a CCD camera. The maximum visual field of the camera unit 21 may be smaller than the inspection subject mounting area of the inspection table 14. In this case, the camera unit 21 divides the image into a plurality of partial images and images the entire inspection object 12. The control unit 30 controls the XY stage 40 so that the camera unit 21 is moved to the next imaging position each time the camera unit 21 captures a partial image. The control unit 30 combines the partial images to generate entire image data of the inspection object 12.

  The illumination unit 22 is configured to project illumination light for imaging by the camera unit 21 on the surface of the inspection object 12. The illumination unit 22 includes one or more light sources that emit light of a wavelength or a wavelength range selected from the wavelength range that can be detected by the imaging element of the camera unit 21. The illumination light is not limited to visible light, and ultraviolet light, X-rays, etc. may be used. When a plurality of light sources are provided, each light source is configured to project light of different wavelengths (for example, red, blue, and green) onto the surface of the inspection object 12 at different projection angles.

  In the inspection apparatus 10 according to the present embodiment, the illumination unit 22 is a side illumination source that projects illumination light in an oblique direction with respect to the inspection surface of the inspection object 12, and in the present embodiment, the upper light source 22a The position light source 22b and the lower light source 22c are provided. In the inspection apparatus 10 according to the present embodiment, the side illumination sources 22a, 22b and 22c are ring illumination sources, respectively, and surround the optical axis of the camera unit 21 and are oblique to the inspection surface of the inspection object 12 Is configured to project illumination light. Each of these side illumination sources 22a, 22b, 22c may be configured by arranging a plurality of light sources in an annular shape. Further, the upper light source 22a, the middle light source 22b and the lower light source 22c, which are side illumination sources, are configured to project illumination light at different angles with respect to the inspection surface.

  The projection unit 23 projects a pattern on the inspection surface of the inspection object 12. The inspection object 12 on which the pattern is projected is imaged by the camera unit 21. The inspection apparatus 10 measures the height of the inspection surface of the inspection object based on the captured pattern image data of the inspection object 12 (image data captured by the camera unit 21 in a state where the pattern is projected on the inspection object 12). Create a map. The control unit 30 detects local inconsistencies in the pattern image data with respect to the projection pattern, and acquires height information of the part based on the local inconsistencies. That is, the change in the imaging pattern with respect to the projection pattern corresponds to the change in height on the inspection surface.

  The projection pattern is preferably a one-dimensional stripe pattern in which bright lines and dark lines are alternately and periodically repeated. The projection unit 23 is arranged to project a stripe pattern from an oblique direction to the inspection surface of the inspection object 12. Discontinuities in height on the inspection surface of the object to be inspected appear as pattern deviations in the pattern image data. Therefore, the height difference can be obtained from the amount of deviation of the pattern. For example, the control unit 30 creates a height map by PMP (Phase Measurement Profilometry) method using a fringe pattern in which the brightness changes according to a sine curve. In the PMP method, the shift amount of the fringe pattern corresponds to the phase difference of the sine curve.

  The projection unit 23 includes a pattern forming device, a light source device for illuminating the pattern forming device, and a projection optical system for projecting the pattern onto the inspection surface of the inspection object 12. The patterning device may be, for example, a variable patterning device capable of dynamically generating a desired pattern such as a liquid crystal display or the like, or fixed patterning in which a pattern is fixedly formed on a substrate such as a glass plate It may be an apparatus. When the patterning device is a fixed patterning device, the projection position of the pattern can be made variable by providing a moving mechanism for moving the fixed patterning device or providing an adjustment mechanism in a projection optical system for pattern projection. Is preferred. Moreover, the projection unit 23 may be configured to be able to switch between a plurality of fixed patterning devices having different patterns.

  A plurality of projection units 23 may be provided around the camera unit 21. The plurality of projection units 23 are arranged to project patterns onto the inspection object 12 from different projection directions. In this way, it is possible to reduce the area where the pattern is not projected due to a shadow due to the height difference on the inspection surface.

  In the above description, the inspection object 12 is fixed, and the imaging unit 20 is moved in the X and Y directions by the XY stage 40. However, the imaging unit 20 is fixed and the inspection object 12 is It may be configured to move in the XY direction.

  The control unit 30 shown in FIG. 1 totally controls the entire apparatus. The hardware is realized by the CPU, memory, and other LSIs of an arbitrary computer, and software is loaded into the memory. Although realized by a program or the like, here, functional blocks realized by their cooperation are illustrated. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

  An example of the configuration of the control unit 30 is shown in FIG. The control unit 30 is configured to include an inspection control unit 31 and a memory 35 which is a storage unit. The inspection control unit 31 includes a height measurement unit 32, an inspection data processing unit 33, and an inspection unit 34. The inspection apparatus 10 further includes an input unit 36 for receiving an input from a user or another device, and an output unit 37 for outputting information related to an inspection, and the input unit 36 and the output unit 37. Are connected to the control unit 30, respectively. The input unit 36 includes, for example, input means such as a mouse and a keyboard for receiving an input from a user, and communication means for communicating with another device. The output unit 37 includes known output means such as a display and a printer.

  The examination control unit 31 is configured to execute various control processes for examination based on the input from the input unit 36 and the examination related information stored in the memory 35. The inspection related information includes two-dimensional image data of the inspection object 12, a height map of the inspection object 12, and substrate inspection data. Prior to the inspection, the inspection data processing unit 33 creates substrate inspection data using the two-dimensional image data and height map of the inspection object 12 that is guaranteed to pass all inspection items. The inspection unit 34 executes an inspection based on the created substrate inspection data and the two-dimensional image data and height map of the inspection object 12 to be inspected.

  The substrate inspection data is inspection data created for each type of substrate. The board inspection data is, so to speak, a collection of inspection data for each solder applied to the board. The inspection data of each solder includes an inspection item necessary for the solder, an inspection window which is an inspection area on the image data of each inspection item, and an inspection standard which is a criterion for determining the quality of each inspection item. One or more examination windows are set for each examination item. For example, in an inspection item for determining the quality of the solder application state, the inspection windows of the same number as the number of solder application areas of the component are usually set in an arrangement corresponding to the arrangement of the solder application areas. In addition, regarding inspection items using image data obtained by subjecting inspection object image data to predetermined image processing, the contents of the image processing are also included in the inspection data.

  The inspection data processing unit 33 sets each item of inspection data in accordance with the substrate as substrate inspection data creation processing. For example, the inspection data processing unit 33 automatically sets the position and size of each inspection window for each inspection item so as to conform to the solder layout of the substrate. The examination data processing unit 33 may receive an input from the user for a part of the examination data. For example, the inspection data processing unit 33 may accept the tuning of the inspection standard by the user. The inspection standard may be set using height information.

  The inspection control unit 31 executes an imaging process of the inspection object 12 as a pre-process of substrate inspection data creation. The inspection object 12 used is one that has passed all inspection items. As described above, the imaging process is performed by illuminating the test object 12 with the illumination unit 22 while controlling the relative movement between the imaging unit 20 and the inspection table 14 and sequentially capturing partial images of the test object 12 . Several partial images are imaged so that the whole to-be-inspected object 12 may be covered. The inspection control unit 31 synthesizes the plurality of partial images, and generates substrate entire surface image data including the entire inspection surface of the inspection object 12. The inspection control unit 31 stores the entire substrate surface image data in the memory 35.

  Further, as shown in FIG. 2, as a pre-processing for height map creation, the inspection control unit 31 projects the pattern onto the inspection object 12 by the projection unit 23 while the imaging unit 20 is relative to the inspection table 14. The movement is controlled, and the pattern image of the inspection object 12 is divided and sequentially imaged. The pattern to be projected is preferably a fringe pattern whose brightness changes according to a sine curve based on the PMP method. The inspection control unit 31 combines the captured divided images to generate pattern image data of the entire inspection surface of the inspection object 12. The inspection control unit 31 stores pattern image data in the memory 35. The pattern image data may be generated not for the whole but for a part of the inspection surface.

  The height measurement unit 32 creates a height map of the entire inspection surface of the inspection object 12 based on the image of the pattern on the pattern image data. The height measuring unit 32 first obtains a local phase difference between the pattern image data and the reference pattern image data (image data captured by the camera unit 21 in a state where the pattern is projected on the reference surface) for the entire image data. Thus, a phase difference map of the inspection surface of the inspection object 12 is obtained. The height measurement unit 32 creates a height map of the inspection object 12 based on the reference surface which is the reference of height measurement and the phase difference map. The reference surface is, for example, the substrate surface of the electronic circuit substrate to be inspected. The reference surface may not necessarily be a flat surface, and may be a curved surface on which a deformation such as a warp of a substrate is reflected.

  Specifically, the height measurement unit 32 is configured to detect a stripe pattern of each pixel of the pattern image data (FIG. 3B) and a pixel of the reference pattern image data (FIG. 3A) corresponding to the pixel. The phase difference (FIG. 3 (c), (d)) is determined. The height measurement unit 32 converts the phase difference into height information. The conversion to height information is performed using the local fringe width in the vicinity of the pixel. It is for compensating that the stripe width on pattern image data changes with places. Because the distance from the projection unit 23 differs depending on the position on the inspection surface, the stripe width changes linearly from one end of the pattern projection area of the inspection surface to the other end even if the stripe width of the reference pattern is constant. It is because it The height measurement unit 32 acquires height information from the reference surface based on the converted height information and the reference surface, and creates a height map of the inspection object 12.

  The inspection control unit 31 creates inspection object image data having a height distribution by associating the height information of the height map of the inspection object 12 with each pixel of the two-dimensional image data of the inspection object 12 You may The inspection control unit 31 may perform three-dimensional modeling display of the inspection object 12 based on the inspection object image data with height distribution. Further, the inspection control unit 31 may superimpose the height distribution on the two-dimensional inspection object image data and display it on the output unit 37. For example, the inspection object image data may be color-displayed by height distribution.

  As described above, acquisition of image data of the inspection object 12 by the imaging unit 20 is controlled by the control unit 30 by controlling the operation of the X drive unit 42, the Y master drive unit 44 and the Y slave drive unit 46 of the XY stage 40. It is done by The position of the imaging unit 20 with respect to the inspection table 14 is determined based on detection values detected by the X-direction position detection unit 41 b, the Y-direction master position detection unit 43 a, and the Y-direction slave position detection unit 45 a.

  The position of the imaging unit 20 with respect to the inspection table 14 can be appropriately set in the inspection device 10. Here, in FIG. 2, the predetermined position at the lower right corner of the inspection table 14 is set as the origin, and the center of the field of view of the camera unit 21 of the imaging unit 20 (the optical axis of the optical system constituting the camera unit 21 and When there is a match, the imaging unit 20 is described as being at the origin. Of course, the origin may be set when the predetermined position of the lower right corner of the inspection table 14 is in the lower right corner of the field of view of the camera unit 21 or the lower left corner of the inspection table 14, the upper right corner, or the upper left corner may be set as the origin. .

  Here, the position of the imaging unit 20 with respect to the inspection table 14 is represented by (x, y). Further, at the time of design of the inspection apparatus 10 according to the present embodiment, the X direction position detection unit 41b, the Y direction master position detection unit 43a, and the Y direction slave when the imaging unit 20 is at the position (x, y) Design values of the position detection unit 45 are (dx, dy1, dy2). In the control unit 30, the correspondence between the position (x, y) and the design values (dx, dy1, d2) is set in advance by an arithmetic expression or a table. For example, the correspondence relationship of design (0, 0, 0) is stored for position (0, 0).

  However, the X direction position detection unit when the X direction guide 41 is adjusted to be orthogonal to the Y direction master guide 43 and the Y direction slave guide 45 due to an assembly error or the like of the XY stage 40 assembled as the inspection apparatus 10 The detection values from 41b, Y-direction master position detection unit 43a, and Y-direction slave position detection unit 45 may be deviated, and the deviations are corrected with correction values ax, ay1, ay2. Specifically, detection values detected from the X-direction position detection unit 41b, the Y-direction master position detection unit 43a, and the Y-direction slave position detection unit 45 when the imaging unit 20 is at the position (x, y) The relationship with (sx, sy1, sy2) is given by the following equation (1).

(X, y) = (sx, sy1, sy2)
= (Dx + ax, dy1 + ay1, dy2 + ay2) (1)

  For example, when moving the imaging unit 20 to the position (x, y), the control unit 30 controls the X-direction position detection unit 41b corresponding to the position (x, y), the Y-direction master position detection unit 43a, and Y The design values (dx, dy1, dy2) of the direction slave position detection unit 45 are determined, and the correction values (ax, ay1, ay2) are read out, and the X direction position detection unit 41b, Y is calculated based on the equation (1). The target values (dx + ax, dy1 + ay1, dy2 + ay2) of the direction master position detection unit 43a and the Y direction slave position detection unit 45 are determined, and the X direction position detection unit 41b, the Y direction master position detection unit 43a, and the Y direction slave The operations of the X drive unit 42, the Y master drive unit 44 and the Y slave drive unit 46 are controlled so that the detection value from the position detection unit 45 becomes this target value.

  On the other hand, when the detection values from the current X direction position detection unit 41b, the Y direction master position detection unit 43a, and the Y direction slave position detection unit 45a are (sx, sy1, sy2), the control unit 30 Based on the equation (1), (sx-ax, sy1-ay1, sy2-ay2) is calculated, and from the design value (dx, dy1, dy2) that becomes this value, the current position (x, x, dy1, dy2) of the imaging unit 20 Determine y). The design value and the correction value are stored, for example, in the memory 35.

  The calculation of the correction values (ax, ay1, ay2) of the X direction position detection unit 41b, the Y direction master position detection unit 43a, and the Y direction slave position detection unit 45a described above (hereinafter referred to as “right angle correction”) is In advance, this is performed using a reference board (glass board) 47 having three signs that are apparently orthogonal (three signs where straight lines connecting them intersect). Specifically, as shown in FIG. 2, a reference board 47 on which three markers MA, MB, MC are formed is placed on the inspection table 14 instead of the inspection object 12, and the camera unit of the imaging unit 20 These markers MA, MB, MC are imaged at 21 to calculate correction values. Here, the origin is at the lower right of FIG. 2, the marker MA is located at the origin, and the marker MB is positioned with a predetermined distance (predetermined distance) in the X-axis direction from the marker MA, marker MC Will be described in the case where the position is determined from the sign MA in the Y-axis direction at a predetermined distance (predetermined distance).

  FIG. 4 shows a flowchart of the quadrature correction process in the control unit 30. When the right angle correction processing is started, control unit 30 first designs X direction position detection unit 41b, Y direction master position detection unit 43a, and Y direction slave position detection unit 45a with respect to origin P0 (0, 0). The value and the current correction value are read from the memory 35 (step 100), and the target value (sx, sy1, sy2) of the origin P0 is determined based on the above equation (1), and the determined value is the target value of the origin P0 Are set (step S101).

  Control unit 30 controls X drive unit 42 and Y master so that detection values of X direction position detection unit 41b, Y direction master position detection unit 43a, and Y direction slave position detection unit 45a become target values of origin P0. The operations of the drive unit 44 and the Y slave drive unit 46 are controlled, and the imaging unit 20 is moved to the origin P0 (step S102).

  The control unit 30 images the mark MA on the reference board 47 with the camera unit 21 and the X drive unit 42, the Y master drive unit 44, and the Y slave drive so that the mark MA is positioned at the center of the visual field area of the camera unit 21. The position PA1 (x, y) of the imaging unit 20 when the marker MA is positioned at the center of the visual field area is detected by controlling the operation of the unit 46 and moving the imaging unit 20 (step S103). It stores in 35 (step S104). The calculation of the position PA1 (x, y) is, as described above, detected values (sx, y) from the current X-direction position detection unit 41b, the Y-direction master position detection unit 43a, and the Y-direction slave position detection unit 45a. It can be calculated based on the above equation (1) using sy1, sy2) and correction values (ax, ay1, ay2).

  The control unit 30 controls the operation of the X drive unit 42 to move the imaging unit 20 in the X axis direction by a predetermined distance (step S105). Here, assuming that the predetermined distance is tx, the target position PB ′ for moving the imaging unit 20 is (tx, 0), and this position PB ′ (tx, 0), the X direction position detection unit 41 b, the Y direction master position The target value is determined based on the equation (1) from the design value of the detection unit 43a and the Y-direction slave position detection unit 45a and the current correction value, and the target value of the X drive unit 42 is determined. The operation is controlled.

  The control unit 30 images the marker MB on the reference board 47 with the camera unit 21 and the X drive unit 42, the Y master drive unit 44, and the Y slave drive so that the marker MB is positioned at the center of the view area of the camera unit 21. The position PB (x, y) of the imaging unit 20 when the marker MB is positioned at the center of the visual field area is detected by controlling the operation of the unit 46 to move the imaging unit 20 (step S106). The position PB is stored in the memory 35 (step S107). The method of detecting the position PB is the same as the position PA1.

  The control unit 30 controls the operations of the X drive unit 42, the Y master drive unit 44, and the Y slave drive unit 46, and moves the imaging unit 20 to the origin P0 (step S108). Then, the control unit 30 images the marker MA of the reference board 47 with the camera unit 21 and the X drive unit 42, the Y master drive unit 44, and Y so that the marker MA is positioned at the center of the visual field area of the camera unit 21. The operation of slave drive unit 46 is controlled to move imaging unit 20, and position PA2 (x, y) of imaging unit 20 when marker MA is located at the center of the visual field area is detected (step S109). The unit position PA2 is stored in the memory 35 (step S110).

  The control unit 30 controls the operations of the Y master drive unit 44 and the Y slave drive unit 46 to move the imaging unit 20 in the Y axis direction by a predetermined distance (step S111). Here, assuming that the predetermined distance is ty, the target position PC 'for moving the imaging unit 20 is (0, ty), and this position PC' (0, ty), the X direction position detection unit 41b, the Y direction master position A target value is determined from the design value of the detection unit 43a and the Y-direction slave position detection unit 45a and the current correction value based on Equation (1), and the Y master drive unit 44 is set to this target value. And the Y slave drive 46 is controlled.

  The control unit 30 images the mark MC on the reference board 47 with the camera unit 21 and the X drive unit 42, the Y master drive unit 44, and the Y slave drive so that the mark MC is positioned at the center of the view area of the camera unit 21. The operation of the unit 46 is controlled to move the imaging unit 20, and the position PC (x, y) of the imaging unit 20 when the marker MC is located at the center of the visual field area is detected (step S112). The position PC is stored in the memory 35 (step S113).

  The positions PA1, PB, PA2, PC calculated by the control unit 30 by the above processing have the relationship shown in FIG. The control unit 30 calculates the angle θ between the straight line PA1-PB (line A1B) and the straight line PA2-PC (line A2C) from the coordinates of the positions PA1, PB, PA2, PC (step S114), and further, this angle The difference Δθ obtained by subtracting 90 ° from θ is calculated (step S115), and it is determined whether the absolute value of the difference Δθ is smaller than a predetermined threshold value (step S116).

  As shown in FIG. 5, when the angle θ between the straight line PA1-PB and the straight line PA2-PC is larger than 90 ° (when Δθ is a positive value), the position PA1 is moved in the D1 direction, and the position PB is D2 By moving in the direction (increasing the correction value ay1 for the Y direction master position detection unit 43a and decreasing the correction value ay2 for the Y direction slave position detection unit 45a), the angle θ can be made close to 90 °. Conversely, when the angle θ is smaller than 90 ° (when Δθ is a negative value), the position PA1 is moved in the opposite direction to D1 and the position PB is moved in the opposite direction to D2 (Y direction master position detection unit The angle θ can be made close to 90 ° by decreasing the correction value ay1 for 43a and increasing the correction value ay2 for the Y-direction slave position detection unit 45a.

  When the control unit 30 determines that the absolute value of the difference Δθ is not smaller than the predetermined threshold (step S116: No), the control unit 30 determines the Y direction master position according to the sign of the difference Δθ as described above. The correction value ay1 and the correction value ay2 for the detection unit 43a and the direction slave position detection unit 45a are corrected by a predetermined value, and the target values sy1 and sy2 of the origin P0 are updated based on the correction values (step S117). Return to and repeat the above process. By repeating the processes of steps S102 to S117, the target values sy1 and sy2 are updated, and the angle θ calculated at step S114 can be made close to 90 °. In the above description, although the correction values ay1 and ay2 are described as fixed values (predetermined values), the magnitude of the value to be corrected is changed according to the magnitude of the absolute value of the difference Δθ. It is also good.

  When the control unit 30 determines that the absolute value of the difference Δθ is smaller than the predetermined threshold (step S116: Yes), the control unit 30 determines the current X direction position detection unit 41b, the Y direction master position detection unit 43a, and The correction values (ax, ay1, ay2) of the Y-direction slave position detection unit 45a are stored in the memory 35 (step S118), and the right angle correction processing is ended.

  As described above, in the inspection apparatus 10 according to the present embodiment, the camera unit 21 captures three markers MA, MB, and MC which are obviously formed in the right angle in advance by the above-described right-angle correction processing. Thus, the X direction position detection unit 41b and the Y direction master position detection unit are arranged such that the X direction guide 41 (first direction) is orthogonal to the Y direction master guide 43 and the Y direction slave guide 45 (second direction). Since the correction values (ax, ay1, ay2) of the Y direction slave position detection unit 45a can be corrected 43a and 43a, the measurement accuracy of the inspection apparatus 10 can be improved.

  Further, in the inspection apparatus 10 according to the present embodiment, the XY stage 40 operates in a state where the X direction guide 41 is orthogonal to the Y direction master guide 43 and the Y direction slave guide 45 by the above-described right angle correction processing. In particular, since the load on the mechanism for moving the X-direction guide 41 with respect to the Y-master drive unit 44 and the Y-slave drive 46 and the Y-direction master guide 43 and the Y-direction slave guide 45 can be reduced, The durability performance of the

  As described above, when the markers MA, MB, and MC formed on the reference board 47 are at the center of the field of view of the camera unit 21 (on the optical axis of the optical system of the camera unit 21), By setting the positions of MA, MB, and MC, it is possible to perform the right angle correction processing independently of the mounting condition of the camera. In addition, since the images of the markers MA, MB, and MC to be imaged are not affected by the aberration of the optical system of the camera unit 21 and the like, accurate positions can be detected.

  Further, as described above, the orthogonal correction processing in the inspection apparatus 10 according to the present embodiment does not require a special sensor or the like for orthogonal correction, and the orthogonal correction can be easily performed with a simple configuration.

  Further, in the right angle correction processing in the inspection apparatus 10 according to the present embodiment, even if the reference board 47 placed on the inspection table 14 is arranged to be inclined, the X direction guide 41 and the Y direction master guide The angles with the 43 and Y direction slave guides 45 can be corrected at right angles. When the angle between the X direction guide 41 and the Y direction master guide 43 and the Y direction slave guide 45 is not a right angle, and the reference board 47 is disposed at an angle, the Y direction is as described above according to the process described above. It can be determined how far the X-direction guide 41 is shifted with respect to the master guide 43 and the Y-direction slave guide 45. Based on the information on the deviation, the angle between the X direction guide 41 and the Y direction master guide 43 and the Y direction slave guide 45 is obtained by repeating the measurement of the sign and the correction of the correction value based on the difference Δθ by the above-mentioned right angle correction processing. Can be brought close to a right angle, and the measurement accuracy of the inspection apparatus 10 can be improved.

  Further, in the reference board 47 used in the above description, only three labels MA, MB, MC are formed, but similar labels may be arranged in two dimensions in advance at known intervals. As described above, since the marker MA is located at the origin, and the markers MB and MC are at a predetermined distance from the marker MA, the above process is performed using the markers at that distance. Can. In this case, of the image data of the camera unit 21, the range used for the orthogonal correction processing is a predetermined range including the optical axis of the camera unit 21 and the predetermined range regardless of the position of the imaging unit 20. Within the range of, it is necessary to be configured so that one sign is always imaged.

  The above embodiment does not limit the invention described in the claims, and all combinations of characteristic items described in the embodiments are essential items of the solution means. Needless to say, it is not limited.

  The apparatus measurement accuracy can be continuously maintained by performing the right angle correction of the XY stage 40 by the method described above not only at the time of apparatus manufacture but also at the time of operation regularly or irregularly.

10 inspection apparatus 20 imaging unit 30 control unit 40 XY stage (imaging unit drive mechanism)
41 X direction guide (first guide)
43 Y Direction Master Guide (2nd Guide)
45 Y Direction Slave Guide (Third Guide)

Claims (4)

An imaging unit for imaging an object to be inspected;
A first guide for moving the imaging unit in a first direction;
A second guide for moving one end side of the first guide in a second direction;
An imaging unit drive mechanism having a third guide for moving the other end side of the first guide in the second direction;
A reference board which is detachable at the position of the object to be inspected and which has an intersection point of two orthogonal straight lines and at least three markers disposed on each of the two straight lines;
A control unit configured to control operation of the first guide, the second guide, and the third guide;
The controller unit is
Imaging each of the three indicia on the reference board with the imaging unit to detect the position of the imaging unit relative to each of the three indicia;
Calculating an angle between the first direction and the second direction from the position of the imaging unit;
Correcting the position of one end of the first guide in the second guide and the position of the other end of the first guide in the third guide so that the angle is approximately 90 °;
And a method of adjusting the inspection apparatus. The step of calculating the angle is
A straight line connecting the position of the sign at the intersection of the two straight lines and the position of the sign on one of the two straight lines; the position of the sign at the intersection of the two straight lines; and the position of the sign on the other of the two straight lines The adjustment method of the inspection apparatus according to claim 1, wherein an angle with a straight line connecting the two is calculated as an angle between the first direction and the second direction. The control unit
A design value which is a correspondence relationship between the position of the imaging unit, the position of one end of the first guide in the second guide, and the position of the other end of the first guide in the third guide;
And the correction value of the design value,
The control unit is configured to determine the position of the imaging unit based on the design value and the correction value.
3. The method according to claim 1, wherein the correcting step calculates and stores the correction value at which the angle is approximately 90 degrees. An imaging unit for imaging an object to be inspected;
A first guide for moving the imaging unit in a first direction;
A second guide for moving one end side of the first guide in a second direction;
An imaging unit drive mechanism having a third guide for moving the other end side of the first guide in the second direction;
A reference board which is detachable at the position of the object to be inspected and which has an intersection point of two orthogonal straight lines and at least three markers disposed on each of the two straight lines;
A control unit that controls the operation of the first guide, the second guide, and the third guide;
The control unit is configured such that an angle between the first direction and the second direction is approximately 90 ° by the adjustment method of the inspection apparatus according to any one of claims 1 to 3. An inspection apparatus characterized by correcting the position of one end of the first guide in the second guide and the position of the other end of the first guide in the third guide.