Substrate measuring apparatus and substrate measuring method

Abstract

In order to provide a substrate measurement device capable of performing high-precision measurement in a short period of time, there are provided a shooting processing section (14) that outputs a trigger signal; a shooting section (2) that shoots an image of a substrate based on the trigger signal, and outputs information of a plurality of images, i.e., an image group, as an image signal; a movement device (4) that changes a relative position between the substrate and the shooting section based on a control signal; an image processing section (10) that calculates coordinates of a feature point shot in the image group based on the image signal, and outputs the coordinates as tentative coordinates; a dynamic error correction amount calculation section (13) that calculates a dynamic error correction amount based on dynamic information obtained by measuring a position, a velocity, or an acceleration with respect to at least one of the substrate and the shooting section, or based on an estimated acceleration obtained by estimating a relative acceleration between the substrate and the shooting section; and a measurement processing section (16) that corrects the tentative coordinates based on a shooting residual, which is a deviation between a target shooting position and a shooting position, or the dynamic error correction amount, and outputs a measurement result of the coordinates of the feature point.

Description

Technical Field

[0001] This invention relates to a substrate measuring apparatus and a substrate measuring method. Background Technology

[0002] In recent years, with the increasing demand for higher productivity of printed circuit boards (hereinafter referred to as boards), there has been a pursuit of improved measurement accuracy and reduced measurement time for boards. Reference 1 discloses a board inspection apparatus in which a linear array camera with linearly arranged imaging elements and a board are moved in a direction perpendicular to the arrangement direction of the imaging elements of the linear array camera. Simultaneously, the apparatus photographs the board based on the coordinates of the moving device measured by a measuring device mounted on the board's moving device. The photographing coordinates are defined as the difference between the pre-calculated control value for the moving device and the actual position measured by the measuring device, added to the coordinates at the time of photographing.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2002-181733 Summary of the Invention

[0004] In the substrate inspection apparatus described in Patent Document 1, when the relative position between the substrate and the linear array camera is moved, vibrations and mechanical deformations occur in the moving device, the imaging unit, etc. This results in errors in the measurement results due to these vibrations and mechanical deformations, leading to reduced measurement accuracy of the substrate. For example, the measurement error increases when calculating the position of the object being photographed based on the image. Furthermore, attempts to improve measurement accuracy require reducing the moving speed, resulting in longer measurement times. The present invention addresses these problems and aims to provide a substrate measurement apparatus or method capable of performing high-precision measurements in a short period of time.

[0005] The substrate measuring apparatus of the present invention comprises: an image processing unit that outputs a trigger signal; an image capturing unit that captures an image of the substrate based on the trigger signal and outputs information of a plurality of images, i.e., an image group, as an image signal; a moving device that changes the relative position between the substrate and the image capturing unit based on a control signal; an image processing unit that calculates the coordinates of feature points captured in the image group based on the image signal and outputs them as provisional coordinates; a dynamic error correction calculation unit that calculates a dynamic error correction amount based on dynamic information obtained by measuring the position, velocity, or acceleration of at least one of the substrate and the image capturing unit, or based on an estimated acceleration obtained by estimating the relative acceleration between the substrate and the image capturing unit; and a measurement processing unit that corrects the provisional coordinates based on the deviation between the target image capturing position and the image capturing position, i.e., the image capturing residual or the dynamic error correction amount, and outputs the measurement result of the coordinates of the feature points.

[0006] Furthermore, in the substrate measurement method of the present invention, a trigger signal is output, and an imaging unit captures an image of the substrate based on the trigger signal. The imaging unit outputs information of multiple images, i.e., an image group, as an image signal. The relative position between the substrate and the imaging unit is changed based on a control signal. The coordinates of the feature points captured in the image group are calculated based on the image signal and output as provisional coordinates. The dynamic error correction amount is calculated based on dynamic information obtained by measuring the position, velocity, or acceleration of at least one of the substrate and the imaging unit, or based on the estimated acceleration obtained by estimating the relative acceleration between the substrate and the imaging unit. The provisional coordinates are corrected based on the deviation between the target shooting position and the shooting position, i.e., the shooting residual or the dynamic error correction amount. The measurement result of the coordinates of the feature points is output.

[0007] The effects of the invention

[0008] According to the present invention, a substrate measuring apparatus or substrate measuring method is provided that can perform high-precision measurements in a short period of time. Attached Figure Description

[0009] Figure 1 This is a diagram illustrating an example of the structure of the substrate measuring device according to Embodiment 1.

[0010] Figure 2 This is a block diagram illustrating an example of the structure of the image processing apparatus according to Embodiment 1.

[0011] Figure 3 This is a flowchart illustrating an example of the substrate measurement operation according to Embodiment 1.

[0012] Figure 4 This is an example of a group of images of holes captured by the imaging unit according to Embodiment 1.

[0013] Figure 5 This is a flowchart illustrating an example of the operation of the dynamic error correction calculation unit according to Embodiment 1.

[0014] Figure 6 This is a diagram illustrating a structural example of the processing circuit of the substrate measuring device according to Embodiment 1, which is composed of a processor and a memory.

[0015] Figure 7 This is a diagram illustrating a structural example of the processing circuitry of the substrate measuring device according to Embodiment 1, which is constructed using dedicated hardware.

[0016] Figure 8 This is a diagram illustrating an example of the structure of the substrate measuring device according to Embodiment 2.

[0017] Figure 9This is a block diagram illustrating an example of the structure of the image processing apparatus according to Embodiment 2.

[0018] Figure 10 This is a diagram illustrating an example of the structure of the substrate measuring device according to Embodiment 3.

[0019] Figure 11 This is a block diagram illustrating an example of the structure of the image processing apparatus according to Embodiment 3.

[0020] Figure 12 This is a flowchart illustrating an example of the processing of the imaging processing unit according to Embodiment 3.

[0021] Figure 13 This is a flowchart illustrating an example of the operation of the imaging processing unit involved in Embodiment 3.

[0022] Figure 14 This is a diagram illustrating an example of the range of high-precision measurements that the substrate measuring apparatus according to Embodiment 3 can perform.

[0023] Figure 15 This is a diagram illustrating an example of the structure of the substrate measuring device according to Embodiment 4.

[0024] Figure 16 This is a block diagram illustrating an example of the structure of the image processing apparatus according to Embodiment 4.

[0025] Figure 17 This is a flowchart illustrating an example of the operation of the image processing apparatus according to Embodiment 4.

[0026] Figure 18 This is a diagram illustrating an example of the structure of the substrate measuring device according to Embodiment 5.

[0027] Figure 19 This is a block diagram illustrating an example of the structure of the image processing apparatus according to Embodiment 5.

[0028] Figure 20 This is a flowchart illustrating an example of the operation of the image processing apparatus according to Embodiment 5. Detailed Implementation

[0029] Hereinafter, embodiments will be described in detail based on the accompanying drawings. Furthermore, the embodiments described below are illustrative, and the scope of the present invention is not limited to the embodiments described below. Additionally, the embodiments described below can be appropriately combined and implemented.

[0030] Implementation Method 1

[0031] Figure 1This diagram illustrates an example of the structure of the substrate measuring apparatus according to this embodiment. The substrate measuring apparatus 100 of this embodiment includes: an image processing unit 1 that outputs a measurement result mr; an imaging unit 2 that captures an image of the substrate b as an image signal is; and a control unit 3 that outputs a control signal CS to a worktable 4 to move the worktable 4. Furthermore, the substrate measuring apparatus 100 includes: a worktable 4 on which the substrate b is placed; and a substrate dynamic information acquisition unit 5-1 that measures the movement of the worktable 4 and outputs substrate dynamic information di1. Additionally, the substrate measuring apparatus 100 includes: an imaging unit dynamic information acquisition unit 5-2 that measures the movement of the imaging unit 2 and outputs imaging unit dynamic information di2; and a position measuring device 6 that measures the position of the worktable 4. Hereinafter, either or both of the substrate dynamic information di1 and the imaging unit dynamic information di2 will sometimes be referred to as dynamic information di.

[0032] Figure 2 This is a block diagram illustrating an example of the structure of the image processing apparatus according to this embodiment. The image processing apparatus 1 includes: an image processing unit 10 that calculates provisional coordinates pc based on an image signal is; a static error correction calculation unit 11 that calculates a static error correction amount sec; and a static error correction parameter storage unit 12 that stores static error correction parameters sp. Additionally, the image processing apparatus 1 includes: a dynamic error correction calculation unit 13 that calculates a dynamic error correction amount dec; an image processing unit 14 that outputs a trigger signal tr; and a data storage unit 15 that stores dynamic information di, image capture time data id, etc. The dynamic error correction calculation unit 13 includes: a vibration correction calculation unit 131 that calculates a vibration correction amount vca; and a mechanical deformation correction calculation unit 132 that calculates a mechanical deformation correction amount mdca. The image processing apparatus 1 can also be, for example, a computer including a signal processing board and an image processing board.

[0033] The imaging unit 2 captures multiple images i. Here, the image obtained by capturing one image is called image i. Furthermore, the image obtained by combining multiple images i is called image group ig. For example, the imaging unit 2 may also include a line scan camera (line scan camera) that arranges multiple image sensor elements in a straight line, a lens that projects an image of the subject, substrate b, etc., onto the light-receiving surface of the image sensor elements, and an illumination unit that illuminates the substrate b, etc. The image sensor element is a component that converts the amount of light incident on the light-receiving surface into an electrical signal. The imaging unit 2 is not limited to a line scan camera; a TDI (Time Delay Integration) camera, for example, can also be used. The time at which the imaging unit 2 captures image i is called the capture time. The determination of the capture time of image i by the image processing unit 14 will be described later.

[0034] The mechanism that changes the relative position between the substrate b and the imaging unit 2 is called a moving device. In this embodiment, the moving device is a worktable 4. A plate mounted on the upper part of the worktable 4 and used to place the substrate b is called a mounting plate. The mounting plate moves, thereby moving the substrate b. The substrate b can also be fixed to the worktable 4 by means of an adsorption device or the like. In this embodiment, the worktable 4 has an x-axis worktable 4-1, which moves the mounting plate and the substrate b along the x-axis. Additionally, the worktable 4 has a y-axis worktable 4-2, which moves the mounting plate and the substrate b along the y-axis. The x-axis worktable 4-1 and the y-axis worktable 4-2 may each have an actuator. Furthermore, in... Figure 1 In the diagram, the x-axis worktable 4-1 and the y-axis worktable 4-2 are combined and referred to as worktable 4, with their individual labels omitted.

[0035] The moving device (worktable 4) of this embodiment changes the relative position between the substrate b and the imaging unit 2 by moving the substrate b along the x-axis and y-axis directions. The moving device of the present invention is not limited to the structure described above; it can be used as long as the relative position between the substrate b and the imaging unit 2 changes. For example, it may be a structure that only moves the imaging unit 2, or it may be a structure that allows both the substrate b and the imaging unit 2 to move independently. Furthermore, the direction of movement of the imaging unit 2, substrate b, etc., can be appropriately selected as needed. For example, it may be one direction, or it may be two or more directions. Alternatively, it may be a structure where the substrate b does not move while the imaging unit 2 moves along the x-axis and y-axis directions. Alternatively, it may be a structure where both the imaging unit 2 and the substrate b can move along the x-axis and y-axis directions.

[0036] The control unit 3 outputs a control signal CS to control the movement of the worktable 4. The control signal CS can be, for example, the position or speed of the worktable 4. Here, the control unit 3 includes: an x-axis controller 31, which controls the movement of the x-axis worktable 4-1; and a y-axis controller 32, which controls the movement of the y-axis worktable 4-2. The dynamic information acquisition unit 5 includes a substrate dynamic information acquisition unit 5-1 and an imaging unit dynamic information acquisition unit 5-2. The substrate dynamic information acquisition unit 5-1 is described as an accelerometer sensor that measures the acceleration of the mounting plate in the x-axis and y-axis directions, fixed to the worktable 4. Here, the acceleration of the mounting plate is practically considered equal to the acceleration of the substrate b. The imaging unit dynamic information acquisition unit 5-2 measures the acceleration of the imaging unit 2 in the x-axis and y-axis directions. An example of the imaging unit dynamic information acquisition unit 5-2 is described as an accelerometer sensor fixed to the imaging unit 2. The object to which the substrate dynamic information acquisition unit 5-1 is fixed is not limited to the mounting plate. As will be described later, the substrate dynamic information acquisition unit 5-1 can be fixed to any member that achieves the effect of measuring the position, velocity, or acceleration of the substrate b; that is, it can be fixed to any member that performs the same action as the substrate b during movement achieved by the moving device. In this invention, when the acceleration sensor is fixed to the mounting plate as in the substrate dynamic information acquisition unit 5-1, the mounting plate is considered to perform an action similar to that of the substrate b within the range of achieving the effects of this invention. Therefore, the substrate dynamic information acquisition unit 5-1 is described as measuring the acceleration of the substrate b.

[0037] The dynamic information acquisition unit 5 is not limited to an accelerometer. Examples of dynamic information acquisition units 5 other than accelerometers include position sensors capable of measuring vibrations, such as Doppler oscillometers, and laser interferometers. As described later in the description of the position measuring device 6, the position measuring device 6 can also be used as the dynamic information acquisition unit 5.

[0038] The substrate dynamic information acquisition unit 5-1 measures the position, velocity, or acceleration of the substrate b and outputs the measurement results as substrate dynamic information di1. Additionally, the imaging unit dynamic information acquisition unit 5-2 measures the position, velocity, or acceleration of the imaging unit 2 and outputs it as imaging unit dynamic information di2. Furthermore, Figure 1 The substrate dynamic information acquisition unit 5-1 and the imaging unit dynamic information acquisition unit 5-2 can each appropriately select the direction of the measured acceleration, etc., as needed. In this embodiment, a worktable 4 is provided to move the substrate b along the x-axis and y-axis directions, but the substrate b and the imaging unit 2 may vibrate, deform mechanically, etc., along the x-axis, y-axis, and z-axis directions. Furthermore, for example, it is also possible to... Figure 1The acceleration in the three directions shown (x-axis, y-axis, and z-axis) is measured, and the dynamic error correction calculation unit 13, described later, calculates the dynamic error correction amount dec for these three directions. Here, acceleration refers to position, velocity, or acceleration. The effects of this invention can be achieved by either the substrate dynamic information acquisition unit 5-1 or the imaging unit dynamic information acquisition unit 5-2 measuring acceleration in at least one direction.

[0039] exist Figure 1 In the structural example of the substrate measuring device 100, it includes both a substrate dynamic information acquisition unit 5-1 and an imaging unit dynamic information acquisition unit 5-2, but either one can be omitted. Furthermore, in Figure 1 In the structural example, the worktable 4 moves the substrate b. Therefore, in Figure 1 In this structure, it is effective to calculate the dynamic error correction amount dec based on the substrate dynamic information di1 output by the substrate dynamic information acquisition unit 5-1. In other words, it is preferable to measure acceleration and the like for the moving object of the mobile device, and it is preferable to have at least the substrate dynamic information acquisition unit 5-1.

[0040] The position measuring device 6 measures the position of the worktable 4 in the x-axis direction and the position of the worktable 4 in the y-axis direction, and outputs the position information pi. Figure 1 The position measuring device 6 includes: an x-axis position measuring device 6-1, which measures the position of the x-axis worktable 4-1; and a y-axis position measuring device 6-2, which measures the position of the y-axis worktable 4-2. The position measuring device 6 may, for example, use a linear scale. Alternatively, an encoder, laser interferometer, or the like mounted on the servo motor that moves the worktable 4 may also be used as the position measuring device 6.

[0041] As mentioned above, the position measuring device 6 can also be used as a dynamic information acquisition unit. The position information pi measured by the position measuring device 6 can be acquired as dynamic information di, and the acceleration can be calculated by performing a second derivative on the position information pi. The calculated acceleration is then used to correct measurement errors. An example of the operation of the position measuring device 6 when it is used as a dynamic information acquisition unit 5 is given. An example of the operation of the x-axis position measuring device 6-1 outputting substrate dynamic information di1 as substrate dynamic information acquisition unit 5-1 will be described. First, the position information pi is saved as substrate dynamic information di1 in the data storage unit 15. The dynamic error correction calculation unit 13 associates the time when the imaging unit 2 captures image i (i.e., the capture time) with the position information pi. Then, the vibration correction calculation unit 131 extracts the vibration position vp at each capture time from the position information pi.

[0042] An example is given of the process for extracting the vibration position vp. For instance, the difference between the position calculated based on the control signal cs and the position information pi can also be used as the vibration position vp. Compared to calculating the vibration position vp using an accelerometer, the amount of data is reduced when calculating the vibration position vp based on the position information pi. In addition, since integration processing is not required, it has the advantages of simplified processing and reduced computational load. The above is an example of the operation of the position measuring device 6 when it is used as the dynamic information acquisition unit 5.

[0043] Figure 3 This is a flowchart illustrating an example of the operation of substrate measurement according to this embodiment. The example shows the image capture process performed by the substrate measuring apparatus 100 in step S101. Figure 1 In this structure, the sensor elements of the line scan camera are arranged along the y-axis. Furthermore, the x-axis stage 4-1 moves the substrate b along the x-axis, which is orthogonal to the y-axis. That is, the x-axis stage 4-1 moves the substrate b along a direction orthogonal to the arrangement direction of the sensor elements of the line scan camera.

[0044] The image processing unit 14 outputs a trigger signal tr to the image capturing unit 2 to control the timing of image capturing. Furthermore, the image capturing unit 2 performs image capturing based on the trigger signal tr at the specified timing. In other words, the image capturing unit 2 performs image capturing at the timing indicated by the trigger signal tr. The image processing unit 14 can also output the trigger signal tr based on position information pi, thereby determining the position of the moving device during image capturing.

[0045] Alternatively, the image processing unit 14 can output a trigger signal tr based on the position information pi obtained from the position measuring device 6, such that the image capturing unit 2 captures image i every time the worktable 4 moves a certain distance, thus obtaining image group ig. Here, the control unit 3 can move the worktable 4 at a constant speed, and the image processing unit 14 can output the trigger signal tr at constant time intervals. Furthermore, it is also possible to perform image capture every time the worktable 4 moves a certain distance without using the position information pi. The image capturing unit 2 outputs the acquired image i or image group ig as an image signal is. Here, the image signal is can be the captured image i or image group ig, or it can be data representing information about image i or image group ig.

[0046] Additionally, the data storage unit 15 stores the shooting time data ID output by the shooting processing unit 14. The shooting time data ID only needs to indicate the moment when the shooting unit performed the shooting, i.e., the shooting time. For example, the shooting time data ID can be data containing the shooting time, or it can be the moment the trigger signal was output. Based on the image group ig, the shooting unit 2 or the image processing unit 10 can obtain an image of a region larger than the region obtained from image i. Furthermore, the shooting unit 2 can also perform shooting at intervals equivalent to the pixel size in the x-axis direction of image i. Thus, a 2D image group ig without gaps or repetitions can also be obtained.

[0047] The pixel size and the operation of the stage 4 are illustrated. Assume that one pixel of the imaging unit 2 is a square with one side measuring 3.5 micrometers, and each side is arranged parallel to the x-axis and y-axis. Furthermore, a lens with a magnification of 1x is mounted on the camera. In this example, one pixel of image i is a square with one side measuring 3.5 micrometers. The imaging processing unit 14 outputs a trigger signal tr such that the imaging unit 2 captures an image every 3.5 micrometers when the stage 4 moves along the x-axis. This is an example of the operation of step S101.

[0048] exist Figure 3 In step S102, the action of calculating the provisional coordinates pc of the feature point based on the image signal is is illustrated. Figure 3 In the action example, the feature point is set as the center coordinate of hole h for explanation. Figure 4 This is an example of an image group ig of the hole captured by the imaging unit 2 according to this embodiment. Figure 4 The black portion within the image group ig is designated as the hole h. Figure 4 In this model, brightness is expressed by the density of the small black dots. That is, the density of black dots is high in dark areas, and decreases as the brightness increases. Compared to other parts of the substrate b, the area with aperture h reflects less light, i.e., has lower luminance, and is therefore darker. Figure 4 The density of black dots in the middle is high.

[0049] The image processing unit 10 acquires the image signal is and detects the position coordinates of the edge of the aperture h. Here, the aperture h is the object being photographed. Furthermore, the object constituting the contour line, edge, region, etc., used to determine the coordinates of feature points is called the object being photographed. For example, the image processing unit 10 may also have a brightness threshold; by determining whether the brightness exceeds the threshold or is less than or equal to the threshold, it distinguishes between the region inside the aperture h and the region outside the aperture h, and detects the boundary between these two regions as an edge. Figure 4As shown, the image processing unit 10, for example, calculates the coordinates of eight points, namely edge detection points e-1 to e-8, which are arranged at equal angular intervals when viewed from the center. Edge detection points e-1 to e-8 are arranged at 45-degree intervals when viewed from the center of the hole. Based on the coordinates of edge detection points e-1 to e-8, the coordinates of the hole center point c in the image group ig are calculated and used as provisional coordinates pc. Alternatively, the centroids of these eight points, e-1 to e-8, can be calculated and used as provisional coordinates pc for the center point c.

[0050] The image processing unit 10 can also directly use the provisional coordinates pc expressed in pixel units. Alternatively, the image processing unit 10 can transform the pixel-based expression into a position coordinate-based expression. Transforming into a position coordinate-based expression involves the image processing unit 10 multiplying the pixel size by the provisional coordinates pc in pixel units. Furthermore, the image processing unit 10 sets a reference point within the image group ig and transforms it into an expression based on position coordinates with that reference point as the origin. Here, position coordinates are coordinates in real space, expressed in units of length. For example, they can also be expressed using units such as meters. The above is an example of the operation of calculating the provisional coordinates pc of the feature point in step S102. Furthermore, the process of transforming the provisional coordinates pc from a pixel-based expression to a position coordinate expression is described as part of step S102. This process is not necessarily performed in step S102. For example, in... Figure 3 Any of steps S101 to S105 can be performed. Furthermore, the process of transforming the pixel-based representation into a position coordinate-based representation can also be performed by structural elements other than the image processing unit 10. For example, it can be performed by the dynamic error correction calculation unit 13, the measurement processing unit 16, etc.

[0051] Furthermore, the object being photographed is not limited to the hole h; any object can be freely selected from which the coordinates of feature points can be determined based on the image signal is of the image group ig containing the object. For example, any object can be freely selected from which the coordinates of feature points can be determined based on the outline, region, etc., of the object that differs from the object in the image group ig. Furthermore, the shape of the object is not limited to a circle. Feature points can also be the center of a hole, the corner of a quadrilateral substrate b, a positioning mark provided on the substrate b, a point on the mounting plate, etc. For example, the object can be a quadrilateral, and the centroid of the quadrilateral's vertices can be designated as feature points. Furthermore, the process of calculating the coordinates of feature points is not limited to the edge detection and arithmetic calculation using the object illustrated in step S102. For example, the image processing unit 10 may include at least: a state quantity observation unit that acquires a state quantity including the image signal is and provisional coordinates pc; and a learning unit that learns the relationship between the image signal is and the provisional coordinates pc based on the state quantity. Furthermore, the image processing unit 10 can also use the model generated by the learning unit through learning to calculate the provisional coordinates pc based on the image signal is. Alternatively, it can have a pre-trained learner obtained through the above-described learning process. The pre-trained learner can, for example, use the model generated through learning to calculate the provisional coordinates pc based on the image signal is.

[0052] In step S103, the process of the static error correction calculation unit 11 calculating the static error correction amount sec based on the static error correction parameter sp is illustrated. It is assumed that the provisional coordinate pc includes both dynamic and static errors. Furthermore, the measurement error of the position coordinates that is not caused by the movement of the moving device is called the static error. In other words, the static error is the measurement error that occurs in both cases where movement is achieved by the moving device and cases where movement is not achieved by the moving device. Additionally, the static error can also be described as the error that occurs when the moving device, i.e., the worktable 4, is stationary and there is no residual vibration caused by the worktable 4. In the case of this embodiment, the static error is the error that is not caused by the movement of the worktable 4. The static error can also be called the geometric error. Examples of causes of static error include deviations in pixel size from the specified value, static rotation of the substrate b depending on its position caused by the installation accuracy of the guide mechanism that moves the worktable 4 on a straight track, and optical distortion of the imaging unit 2, which is called distortion.

[0053] The static error correction calculation unit 11 obtains the static error correction parameter sp stored in the static error correction parameter storage unit 12, and calculates the static error correction amount sec based on the static error correction parameter sp. Examples of static error correction parameters sp can be the specification values ​​and measured values ​​of the imaging unit 2, the worktable 4, etc. Alternatively, the static error correction parameter sp can be obtained through experimentation and stored in the static error correction parameter storage unit 12.

[0054] For example, position coordinates can be pre-obtained using a measuring device different from the substrate measuring device 100. Furthermore, the position coordinates are measured by the substrate measuring device 100 in an environment unaffected by the movement of the moving device. The static error correction parameter sp can also be determined by comparing the measurement results of the two position coordinates. Alternatively, for example, the static error correction parameter sp can be determined by comparing the difference between the position coordinates before and after movement, calculated based on the control signal cs, with the measurement results obtained by the substrate measuring device 100 in an environment unaffected by movement.

[0055] Alternatively, for example, the static error correction parameter sp can be calculated by comparing the difference in position coordinates between the point before and after the movement, obtained from the measurement by the laser length measuring device, with the measurement result of the substrate measuring device 100 in an environment unaffected by the movement. Here, the measurement result of the substrate measuring device 100 can also be used as the output from the measurement processing unit 16 when the static error correction amount sec is zero. Furthermore, step S103 can be omitted. In other words, the static error correction amount calculation unit 11 and the static error correction parameter storage unit 12 can be omitted from the image processing device 1, and... Figure 3 The processing is set to omit the correction of static error.

[0056] In step S104, an example is shown of the dynamic error correction calculation unit 13 calculating the dynamic error correction amount dec based on the substrate dynamic information di1 and the imaging unit dynamic information di2. Here, the error in position coordinates caused by the movement of the moving device is called dynamic error. In other words, dynamic error is a measurement error that occurs when the movement performed by the moving device meets the specified conditions, and does not occur when the moving device is stationary and there is no residual vibration. In this embodiment, the dynamic error is the error caused by the movement of the stage 4. Furthermore, dynamic error is not only generated when the moving device is accelerating or decelerating, but also when it is not accelerating or decelerating due to residual vibration. Therefore, it should be noted that sometimes dynamic error correction is needed not only when the moving device is accelerating or decelerating, but also when it is not accelerating or decelerating.

[0057] Figure 5 This is a flowchart illustrating an example of the operation of the dynamic error correction calculation unit 13 according to this embodiment. Additionally, Figure 5 It means Figure 4 A flowchart illustrating an example of step S104 is provided. In step S111, the operation of the dynamic error correction calculation unit 13 in associating the provisional coordinate pc with the substrate dynamic information di1 and the imaging unit dynamic information di2 based on the shooting time data will be described. By associating the provisional coordinate pc with the dynamic information di, the dynamic error correction calculation unit 13 calculates the dynamic error correction amount dec at the provisional coordinate pc, or calculates the dynamic error correction amount dec at the shooting time of the image containing the provisional coordinate pc. The dynamic error correction calculation unit 13 obtains the shooting time data id, the substrate dynamic information di1, and the imaging unit dynamic information di2 from the data storage unit 15.

[0058] The substrate dynamic information di1 and the imaging unit dynamic information di2 include the time when the dynamic information di was measured, i.e., the measurement time. The measurement time is the time when the substrate dynamic information acquisition unit 5-1 and the imaging unit dynamic information acquisition unit 5-2 obtain the measurement results. Furthermore, based on the imaging time data id, the imaging time of each image i is associated with a provisional coordinate pc, and the imaging time of each image i is associated with the substrate dynamic information di1 and the imaging unit dynamic information di2 measured at that imaging time. Thus, each provisional coordinate pc is associated with the substrate dynamic information di1 and the imaging unit dynamic information di2. In other words, the dynamic error correction calculation unit 13 associates each image i containing the provisional coordinate pc with the dynamic information di measured at the imaging time of each image i. The above describes how... Figure 5 The action is associated with the provisional coordinate pc and the dynamic information di1 of the substrate and the dynamic information di2 of the imaging unit.

[0059] Here, the processing in step S111 only requires associating the provisional coordinate pc with the dynamic information di at the same shooting time, and is not limited to the processing exemplified above. For example, the dynamic error correction calculation unit 13 can also obtain the trigger signal tr instead of the shooting time data id, calculate the shooting time based on the trigger signal tr, and associate the provisional coordinate pc with the dynamic information di. Alternatively, for example, the dynamic error correction calculation unit 13 can also obtain the control signal cs from the control unit 3 and calculate the position of the feature point based on the control signal cs.

[0060] In step S112, the processing of the vibration correction calculation unit 131, which calculates the vibration correction amount vca based on the dynamic information di, will be described. The vibration correction calculation unit 131 calculates the substrate vibration position vp for each provisional coordinate pc based on the substrate dynamic information di1 associated with the provisional coordinate pc in step S111. Additionally, it calculates the imaging unit vibration position vpa based on the imaging unit dynamic information di2. Here, the substrate vibration position vp and the imaging unit vibration position vpa are the positional changes of the substrate b and the imaging unit 2 caused by the vibration.

[0061] When the substrate dynamic information di1 is the acceleration of substrate b, the vibration component is calculated based on the substrate dynamic information di1, and the value obtained by integrating the calculated vibration component twice is taken as the substrate vibration position vp. Alternatively, when the substrate dynamic information di1 is the velocity of substrate b, the vibration component is calculated based on the substrate dynamic information di1, and the value obtained by integrating the calculated vibration component once is taken as the substrate vibration position vp. When the substrate dynamic information di1 is the relative position of substrate b, the vibration component is calculated based on the substrate dynamic information di1, and the calculated vibration component is taken as the substrate vibration position vp. Here, the substrate dynamic information di1 can also be compared with the command signal cs, and the vibration component can be calculated based on the substrate dynamic information di1. For example, when the substrate dynamic information di1 is the acceleration of substrate b, the value obtained by subtracting the acceleration of substrate b calculated based on the command signal cs from the substrate dynamic information di1 can also be used as the vibration component.

[0062] Similarly, when the dynamic information di2 of the imaging unit is the acceleration of the imaging unit 2, the vibration component is calculated based on the dynamic information di2, and the value obtained by integrating the calculated vibration component twice is taken as the vibration position vpa of the imaging unit. Alternatively, when the dynamic information di2 of the imaging unit is the velocity of the imaging unit 2, the vibration component is calculated based on the dynamic information di2, and the value obtained by integrating the calculated vibration component once is taken as the vibration position vpa of the imaging unit. When the dynamic information di2 of the imaging unit is the position of the imaging unit 2, the vibration component is calculated based on the dynamic information di2, and the calculated vibration component is taken as the vibration position vpa. For example, when the dynamic information di2 of the imaging unit is the acceleration of the imaging unit 2, since the imaging unit 2 does not undergo movement implemented by the moving device in this embodiment, the dynamic information di2 of the imaging unit can also be used as the vibration component.

[0063] Next, the vibration correction calculation unit 131 calculates the difference between the substrate vibration position vp and the imaging unit vibration position vpa, and uses this difference as the relative vibration position rvp. The vibration correction calculation unit 131 uses this relative vibration position rvp as the vibration correction amount vca. Alternatively, the relative vibration position rvp can be calculated as a vector having components in multiple directions, and each of these components can be used as the directional component of the vibration correction amount vca.

[0064] Furthermore, either the substrate dynamic information acquisition unit 5-1 or the imaging unit dynamic information acquisition unit 5-2 can be omitted. When the imaging unit dynamic information acquisition unit 5-2 is omitted, the substrate vibration position vp is used as the vibration correction amount vca. Alternatively, when the substrate dynamic information acquisition unit 5-1 is omitted, the imaging unit vibration position vpa is used as the vibration correction amount vca. The above is an example of the process of determining the vibration correction amount vca in step S112.

[0065] In step S113, the processing of the vibration correction calculation unit 131, which calculates the mechanical deformation correction amount mdca based on the dynamic information di, will be described. The mechanical deformation correction amount calculation unit 132 obtains the substrate dynamic information di1, the imaging unit dynamic information di2, and the dynamic correction parameter dcp. Here, the dynamic correction parameter dcp is a parameter that associates the substrate dynamic information di1 and the imaging unit dynamic information di2 with the mechanical deformation correction amount mdca.

[0066] Examples of dynamic correction parameters dcp can be given, including parameters related to mechanical deformation and rigidity of the worktable 4, imaging unit 2, and substrate measuring device 100. The dynamic correction parameter dcp can also be calculated based on specifications such as the material, shape, rigidity, and weight of the worktable 4. Alternatively, the dynamic correction parameter dcp can be determined through prior testing. Examples of tests can be given, such as measuring the mechanical deformation generated in the worktable 4, imaging unit 2, and substrate measuring device 100 when the worktable 4 is moved, or when the worktable 4 and imaging unit 2 are accelerated or decelerated.

[0067] Examples of mechanical deformation include pitch deformation and yaw deformation. Here, the two types of mechanical deformation resulting from the application of an inertial force in the opposite direction to the acceleration direction are referred to as pitch deformation and yaw deformation. Pitch deformation and yaw deformation can also be, for example, two types of deformation that involve rotation around two mutually orthogonal axes passing through the center of gravity of the deformable object, which becomes the subject of the deformation. An example of pitch deformation will be explained when the deformable object is the worktable 4. When the position of the substrate b is far from the drive axis of the worktable 4, the worktable 4 deforms by tilting to the side opposite to the acceleration direction. Furthermore, a measurement error is generated in the provisional coordinate pc due to the mechanical deformation of the worktable 4. This is an example of pitch deformation.

[0068] Furthermore, an example of yaw deformation will be explained by setting the deformable object as the worktable 4. Assume that the center of gravity of the portion fixed to the upper surface of the y-axis worktable 4-2 of the worktable 4 is off-center. In other words, the x-axis worktable 4-1 is fixed relative to the upper surface of the y-axis worktable 4-2, and the mounting plate is fixed relative to the upper surface of the x-axis worktable 4-1, with the x-axis worktable 4-1 in an eccentric state in the positive or negative x-axis direction. In this state, if the y-axis worktable 4-2 is accelerated or decelerated, an inertial force acts on the worktable 4, causing the worktable 4 to deform and rotate about an axis parallel to the z-axis. This results in a measurement error in the provisional coordinate pc due to mechanical deformation. This is an example of yaw deformation.

[0069] Similar to step S112, the substrate dynamic information di1 and the imaging unit dynamic information di2 are associated with the imaging time. An example is shown of the operation of calculating the mechanical deformation correction amount mdca for each imaging time using the substrate dynamic information di1 and the imaging unit dynamic information di2 for each imaging time.

[0070] Assuming an inertial force proportional to acceleration acts on a deformable object due to the movement of the moving device, mechanical deformation proportional to the inertial force is generated on the deformable object. Furthermore, the dynamic correction parameter storage unit 17 stores the proportionality coefficient between the acceleration of the substrate b and the substrate-side mechanical deformation bmd, and the proportionality coefficient between the acceleration of the imaging unit 2 and the imaging unit-side mechanical deformation iumd, as dynamic correction parameters dcp. Here, the substrate-side mechanical deformation bmd is the displacement of the substrate b caused by mechanical deformation. Additionally, the imaging unit-side mechanical deformation iumd is the displacement of the imaging unit 2 caused by mechanical deformation.

[0071] The mechanical deformation correction calculation unit 132 uses the difference between the mechanical deformation mbd on the substrate side and the mechanical deformation iumd on the imaging unit side as the mechanical deformation correction amount mdca. The mechanical deformation correction amount mdca is the mechanical deformation displacement of the substrate as observed from the imaging unit. Therefore, the relative displacement between the imaging unit 2 and the substrate b can be calculated and used as the mechanical deformation displacement mdca.

[0072] Here, when the substrate dynamic information di1 and the imaging unit dynamic information di2 are accelerations, they are used as accelerations when calculating the mechanical deformation mbd on the substrate side and the mechanical deformation iumd on the imaging unit side. Furthermore, when the substrate dynamic information di1 and the imaging unit dynamic information di2 are velocities, the values ​​obtained by performing a first derivative on them are used as accelerations when calculating the mechanical deformation mbd on the substrate side and the mechanical deformation iumd on the imaging unit side. When the substrate dynamic information di1 and the imaging unit dynamic information di2 are positions, the values ​​obtained by performing a second derivative on them are used as accelerations when calculating the mechanical deformation mbd on the substrate side and the mechanical deformation iumd on the imaging unit side. Additionally, a smoothing filtering process can be performed on the substrate dynamic information di1 and the imaging unit dynamic information di2 before performing the derivative calculation. The above is an example of the processing in step S113.

[0073] Furthermore, as described above, either the substrate dynamic information acquisition unit 5-1 or the imaging unit dynamic information acquisition unit 5-2 can be omitted. When the imaging unit dynamic information acquisition unit 5-2 is omitted, the mechanical deformation correction calculation unit 132 uses the substrate-side mechanical deformation mbd as the mechanical deformation correction amount mdca. Alternatively, when the substrate dynamic information acquisition unit 5-1 is omitted, the mechanical deformation correction calculation unit 132 uses the imaging unit-side mechanical deformation iumd as the mechanical deformation correction amount mdca.

[0074] In step S114, the operation of the dynamic error correction calculation unit 13, which calculates the dynamic error correction amount dec based on the vibration correction amount vca and the mechanical deformation correction amount mdca, is illustrated. The dynamic error correction calculation unit 13 uses the sum of the vibration correction amount vca and the mechanical deformation correction amount mdca as the dynamic error correction amount dec. Alternatively, the vibration correction amount vca and the mechanical deformation correction amount mdca can be set as vectors having x-axis and y-axis components, and the dynamic error correction amount dec can be calculated as a vector. This is an example of the operation of the dynamic error correction calculation unit 13 in step S114. Furthermore, as explained above... Figure 5 The action is Figure 4 This is an example of the process of calculating the dynamic error correction amount dec in step S104.

[0075] exist Figure 4 In step S105, the operation of the measurement processing unit 16, which corrects the provisional coordinate pc based on the static error correction amount sec and the dynamic error correction amount dec, is illustrated. The measurement processing unit 16 acquires the provisional coordinate pc, the static error correction amount sec, and the dynamic error correction amount dec, and outputs the value obtained by subtracting the static error correction amount sec and the dynamic error correction amount dec from the provisional coordinate pc as the measurement result mr. For example, the provisional coordinate pc and the measurement result mr can also be quantities having values ​​in the x-axis direction and the y-axis direction.

[0076] Furthermore, the measurement processing unit 16 can also apply coordinates to points that are different from the feature points. Figure 3 The correction described in steps S101 to S105 outputs the relative position of the feature point with respect to the point to which the correction was applied as the measurement result mr. Examples of points different from the feature point mentioned above include, for example, if the feature point is the center coordinate of a hole, positioning marks set on the printed circuit board, corners of the printed circuit board, etc.

[0077] When dynamic error correction is performed in the image processing step, it is necessary to correct the error for each image i acquired by the imaging unit 2, requiring multiple complex steps to improve measurement accuracy. On the other hand, in this embodiment, the substrate measuring apparatus 100 calculates the provisional coordinate pc based on the image signal is by the image processing unit 10. Furthermore, it is not necessary to perform error correction for each image i in order to perform correction for the provisional coordinate pc. Therefore, compared to the case where dynamic error correction is performed in the image processing step, the computational load can be reduced. In addition, high-speed processing is possible.

[0078] The substrate dynamic information di1 includes information about the movement of the substrate b. Therefore, the substrate measuring apparatus 100 according to this embodiment can perform corrections for measurement errors reflecting vibrations, mechanical deformations, etc., of the substrate b. Furthermore, the imaging unit dynamic information di2 includes information about the movement of the imaging unit 2. Therefore, the substrate measuring apparatus 100 according to this embodiment can perform corrections for measurement errors reflecting vibrations, mechanical deformations, etc., of the imaging unit 2. In addition, by acquiring the substrate dynamic information di1 or the imaging unit dynamic information di2 in the y-axis direction, z-axis direction, etc., in addition to the x-axis direction, corrections for dynamic errors reflecting vibrations, mechanical deformations, etc., in directions different from the movement direction of the moving device can be performed.

[0079] Alternatively, when calculating the dynamic error correction amount dec, the provisional coordinate pc and the dynamic error correction amount dec can be newly estimated through interpolation based on the provisional coordinate pc and multiple sets of dynamic error correction amounts dec corresponding to the provisional coordinate pc. An example is shown of the process of estimating the provisional coordinate pc and the dynamic error correction amount dec through interpolation.

[0080] Assume the dynamic error correction dec for a provisional coordinate pc of 5 pixels is 2 micrometers. Also, assume the dynamic error correction dec for a provisional coordinate pc of 6 pixels is 3 micrometers. Then, by applying linear interpolation to the dynamic correction dec for these two positions, the dynamic error correction dec for a provisional coordinate pc of 5.5 pixels is found to be 2.5 micrometers. This is an example of estimating the relationship between the provisional coordinate pc and the dynamic error correction dec obtained through interpolation. Although this example uses linear interpolation with a first-order function, the form of the interpolation function is not limited to a first-order function; a second-order function can also be appropriately chosen. For example, multiple provisional coordinate pcs and dynamic error correction decs obtained by the method described in this embodiment can be fitted, thereby selecting the appropriate function.

[0081] exist Figure 3 , Figure 5 In the example described above, the association process is illustrated by linking the substrate dynamic information di1 and the imaging unit dynamic information di2 with the provisional coordinate pc, performed via the shooting time. As another example, when the stage 4 moves at a constant speed and the imaging unit 2 performs shooting at constant time intervals, the image signal is is associated with the shooting time, thus enabling the association of the substrate dynamic information di1 with the provisional coordinate pc without relying on the shooting time. Furthermore, the dynamic error correction amount dec can be calculated for each provisional coordinate pc.

[0082] Although Figure 1, Figure 2 The structure shown includes both a vibration correction calculation unit 131 and a mechanical deformation correction calculation unit 132, but either one can be omitted. The dynamic correction amount dec is calculated based on either the vibration correction amount vca or the mechanical deformation correction amount mdca. Furthermore, if the mechanical deformation correction calculation unit 132 is omitted, the dynamic correction parameter storage unit 17 can also be omitted.

[0083] Figure 6 This diagram illustrates a structural example of the processing circuit of the substrate measuring apparatus according to this embodiment, which is configured with a processor and a memory. When the processing circuit is configured with a processor 10001 and a memory 10002, each function of the processing circuit of the substrate measuring apparatus 100 is implemented by software, firmware, or a combination of software and firmware. The software, firmware, etc., are described as programs and stored in the memory 10002. In the processing circuit, each function is implemented by the processor 10001 reading and executing the program stored in the memory 10002. That is, the processing circuit has a memory 10002, which stores the program that ultimately enables the processing of the substrate measuring apparatus 100 to be executed. Furthermore, the program can also be described as a process and method for a computer to execute the substrate measuring apparatus 100. Here, the processor 10001 can be a CPU (Central Processing Unit), a processing device, an arithmetic unit, a microprocessor, a microcomputer, a DSP (Digital Signal Processor), etc. The memory 10002 can be, for example, a non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable ROM), or EEPROM (Electrically EPROM). Alternatively, the memory 10002 can be a disk, floppy disk, optical disk, compact disc, mini-disk, or DVD (Digital Versatile Disc).

[0084] Figure 7 This diagram illustrates a structural example of the processing circuitry of the substrate measuring apparatus according to this embodiment, constructed using dedicated hardware. In the case where the processing circuitry is constructed using dedicated hardware... Figure 7The processing circuit 10003 shown may be, for example, a single circuit, a composite circuit, a programmable processor, a parallel programmable processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. The functions of the substrate measuring device 100 can be implemented by the processing circuit 10003 on a functional basis, or multiple functions can be implemented by the processing circuit 10003 in a combined manner.

[0085] The hardware components, including the imaging unit 2, control unit 3, worktable 4, motion information acquisition unit 5, and position measuring device 6, are collectively referred to as the substrate measurement mechanism. The processing circuitry does not necessarily need to be located near the substrate measurement mechanism. For example, it could also be... Figure 1 The image processing device 1 is configured as a processing circuit, and is placed in a location far from the substrate measuring mechanism, with the two connected via a network. Alternatively, for example, the image processing device 1 may be configured as a processing circuit on a cloud server.

[0086] As described above, the substrate measuring apparatus 100 illustrated in this embodiment includes an image processing unit 14 that outputs a trigger signal tr. Additionally, it includes an image capturing unit 2 that captures images of the substrate b based on the trigger signal tr and outputs information from multiple images i, i.e., image group ig, as an image signal is. Furthermore, the substrate measuring apparatus 100 includes a moving device (worktable 4) that changes the relative position between the substrate b and the image capturing unit 2 based on a control signal CS; and an image processing unit 10 that calculates the coordinates of feature points captured in the image group ig based on the image signal is and outputs them as provisional coordinates pc.

[0087] Furthermore, the substrate measuring apparatus 100 includes a dynamic error correction calculation unit 13. The dynamic error correction calculation unit 13 calculates the dynamic error correction amount dec based on dynamic information di or on an estimated acceleration ea. Here, the dynamic information di is obtained by measuring the position, velocity, or acceleration of at least one of the substrate b and the imaging unit 2. The estimated acceleration ea is obtained by estimating the relative acceleration between the substrate b and the imaging unit 2. Additionally, the substrate measuring apparatus 100 includes a measurement processing unit 16. The measurement processing unit 16 corrects the provisional coordinate pc based on the deviation between the target imaging position and the imaging position, i.e., the imaging residual re, or the dynamic error correction amount dec, and outputs the measurement result mr of the feature point coordinates.

[0088] Furthermore, the structure for calculating the dynamic error correction amount dec based on the estimated acceleration ea obtained from the relative acceleration between the substrate b and the imaging unit 2 will be described later in Embodiment 4. Additionally, the structure for correcting the provisional coordinate pc based on the imaging residual re and outputting the measurement result mr of the feature point coordinates will be described later in Embodiment 5.

[0089] Furthermore, according to an example of the substrate measurement method exemplified in this embodiment, a trigger signal tr is output. Additionally, the imaging unit captures image i of the substrate b based on the trigger signal tr, and the imaging unit 2 outputs information from multiple images i, i.e., image group ig, as an image signal is. Furthermore, the relative position between the substrate b and the imaging unit 2 is changed based on the control signal CS. Additionally, the coordinates of feature points captured in the image group ig are calculated based on the image signal is and output as provisional coordinates pc.

[0090] Furthermore, in this substrate measurement method, a dynamic error correction amount dec is calculated based on dynamic information di obtained by measuring the position, velocity, or acceleration of at least one of the substrate b and the imaging unit 2, or an estimated acceleration ea obtained by estimating the relative acceleration between the substrate b and the imaging unit 2. Additionally, a provisional coordinate pc is corrected based on the deviation between the target imaging position and the imaging position, i.e., the imaging residual re, or the dynamic error correction amount dec, and the measurement result mr of the feature point coordinates is output. According to this substrate measurement apparatus or substrate measurement method, correction is performed after measuring the coordinates of the feature points from the image group ig as provisional coordinates. Therefore, it is not necessary to perform error correction processing for each image i. Thus, the computational processing load can be reduced.

[0091] Furthermore, according to an example of the substrate measuring apparatus 100 of this embodiment, the dynamic error correction calculation unit 13 has at least one of a vibration correction calculation unit 131 or a mechanical deformation correction calculation unit 132. The vibration correction calculation unit 131 calculates the vibration correction amount vca based on the dynamic information di. The mechanical deformation correction calculation unit 132 calculates the mechanical deformation correction amount mdca based on the dynamic information di and the dynamic correction parameter dcp. The dynamic error correction calculation unit 13 calculates the dynamic error correction amount dec based on at least one of the vibration correction amount vca or the mechanical deformation correction amount mdca.

[0092] In another example of the substrate measuring apparatus 100 in this embodiment, the dynamic error correction calculation unit 13 calculates the dynamic error correction amount dec when the provisional coordinate pc is set, or calculates the dynamic error correction amount dec at the time of capturing an image including the provisional coordinate pc.

[0093] In one example of the substrate measuring apparatus 100 in this embodiment, the imaging unit 2 is a line scan camera. The imaging unit 2 performs imaging while changing the relative position between the substrate b and the imaging unit 2 in a direction perpendicular to the arrangement direction of the plurality of imaging elements of the line scan camera. The imaging processing unit 14 outputs a trigger signal tr such that the magnitude of the change in relative position between the substrate b and the imaging unit 2 between two consecutive images remains constant. When a line scan camera is used as the imaging unit 2, the direction of frequent movement can be set to a single direction, simplifying the processing of image groups ig. Furthermore, when the imaging unit 2 performs imaging while changing the relative position between the substrate b and the imaging unit 2 in a direction perpendicular to the arrangement direction of the plurality of imaging elements of the line scan camera, the coordinates of feature points distributed over a large area can be measured quickly and accurately.

[0094] Furthermore, in one example of the substrate measuring apparatus 100 according to this embodiment, the dynamic information acquisition unit 5 is configured as an accelerometer. When the dynamic information acquisition unit 5 is configured as an accelerometer, it is smaller and easier to install compared to using a position measuring device 6 or similar device as the dynamic information acquisition unit 5. Additionally, the degree of freedom in the installation position is increased.

[0095] Furthermore, according to one example of the substrate measuring apparatus 100 of this embodiment, a static error correction calculation unit 11 is also included. This static error correction calculation unit 11 calculates a correction amount, namely a static error correction amount sec, for the measurement error, which occurs when the moving device (worktable 4) is stationary and there is no residual vibration caused by the moving device, based on the static error correction parameter sp. The measurement processing unit 16 calculates the measurement result mr based on the static error correction amount sec. As a result, measurements with minimal static error impact can be performed.

[0096] According to this embodiment, a substrate measuring apparatus or substrate measuring method capable of performing high-precision measurements in a short period of time can be provided.

[0097] Implementation Method 2

[0098] Figure 8This diagram illustrates an example of the structure of the substrate measuring apparatus according to this embodiment. In the substrate measuring apparatus 100 of Embodiment 1, images are taken while the substrate b is moved along the x-axis. In contrast, in the substrate measuring apparatus 100a, images are taken while the imaging unit 2 is moved along the x-axis. In this embodiment, signals and structural elements that are the same as or correspond to those in Embodiment 1 are labeled with the same reference numerals. Furthermore, in the description of the substrate measuring apparatus 100a, to avoid repetition, the description focuses on the differences from the substrate measuring apparatus 100 of Embodiment 1.

[0099] The substrate measuring device 100a of this embodiment has a worktable 4a instead of a table. Figure 1 The substrate measuring apparatus 100 shown has a worktable 4. Additionally, the substrate measuring apparatus 100a has a position measuring device 6a instead of a position measuring device 6, and a control unit 3a instead of a control unit 3. Furthermore, the substrate measuring apparatus 100a has an image processing device 1a instead of the image processing device 1 of Embodiment 1.

[0100] The worktable 4a is a moving device that changes the relative position of the imaging unit 2 and the substrate b in the x-axis direction. The worktable 4a has an x-axis worktable 4a-1 instead of the x-axis worktable 4-1 in Embodiment 1. The x-axis worktable 4-1 moves the substrate b along the x-axis direction, and in contrast, the x-axis worktable 4a-1 moves the imaging unit 2 along... Figure 8 The coordinate axis moves in the x-axis direction.

[0101] The control unit 3a has an x-axis controller 31a instead of the x-axis controller 31 in Embodiment 1. The x-axis controller 31 controls the movement of the x-axis stage 4-1 to move the substrate b. On the other hand, the x-axis controller 31a controls the x-axis stage 4a-1 to move the imaging unit 2. Figure 8 The position measuring device 6a shown differs from the position measuring device 6 in that it has an x-axis position measuring device 6a-1 that measures the position of the imaging unit 2 in the x-axis direction instead of the x-axis position measuring device 6-1.

[0102] Figure 9 This is a block diagram illustrating an example of the structure of the image processing apparatus according to this embodiment. The image processing apparatus 1a has an image processing unit 14a instead of an image processing unit 14. Additionally, it has a dynamic error correction amount calculation unit 13a instead of a dynamic error correction amount calculation unit 13. Apart from this, the structure of the substrate measuring apparatus 100a is similar to... Figure 1 , Figure 2 The substrate measuring device 100 shown is the same.

[0103] The image processing apparatus 1a of this embodiment performs the same operation as the image processing apparatus 1. Figure 3 Image processing is performed according to the various processes shown. For Figure 3 The differences between image processing device 1a and image processing device 1 in each process will be explained. Figure 3 In step S101, in one example of the operation of the imaging processing unit 14, the substrate b outputs a trigger signal tr every time it moves a certain distance. On the other hand, in one example of the operation of the imaging processing unit 14a, based on the position information pi from the x-axis position measuring device 6a-1, the imaging unit 2 outputs a trigger signal tr every time it moves a certain distance along the x-axis. Furthermore, when the imaging unit 2 moves at a constant speed, the imaging processing unit 14a can also output the trigger signal tr at a constant time interval.

[0104] Furthermore, the dynamic error correction calculation unit 13a is similar to the dynamic error correction calculation unit 13 in that it... Figure 3 In step S104, execute with Figure 5 The processing is the same for all processes. Figure 5 In each process, the dynamic error correction calculation unit 13a replaces the control unit 3a and uses the control signal cs from the control unit 3a to calculate the dynamic error correction amount dec. The above are the differences between the operation of the image processing device 1a and the operation of the image processing device 1.

[0105] Furthermore, similar to the substrate measuring device 100, the substrate measuring device 100a can also be configured to omit either the vibration correction calculation unit 131a or the mechanical deformation correction calculation unit 132a from the dynamic error correction calculation unit 13a. Additionally, similar to the substrate measuring device 100, the substrate measuring device 100a can also be configured to omit either the substrate dynamic information acquisition unit 5-1 or the imaging unit dynamic information acquisition unit 5-2. Furthermore, similar to the substrate measuring device 100, the substrate measuring device 100a can also be configured to omit the static error correction calculation unit 11.

[0106] Figure 8The imaging unit 2 moves via the x-axis stage 4a-1, and therefore tends to have a larger dynamic error due to vibration, mechanical deformation, etc., of the imaging unit 2 compared to the substrate measuring device 100. Therefore, the dynamic error correction based on the dynamic information di2 of the imaging unit is more effective in the substrate measuring device 100a compared to the substrate measuring device 100. Furthermore, with the movement of the imaging unit 2 caused by the x-axis stage 4a-1, vibration, mechanical deformation, etc., may occur not only in the x-axis direction, but also in the y-axis and z-axis directions. Moreover, the further the imaging unit 2 is from the moving device, i.e., the feed axis of the x-axis stage 4a-1, the greater the vibration, mechanical deformation, etc., in directions different from the movement direction of the x-axis stage 4a-1. In other words, the dynamic error tends to increase in directions different from the movement direction of the x-axis stage 4a-1.

[0107] As described above, according to this embodiment, a substrate measuring apparatus or substrate measuring method can be provided that can perform high-precision measurements in a short period of time even in a structure where the imaging unit 2 moves. Furthermore, since the substrate measuring apparatus 100a is a structure where the imaging unit 2 moves, the effect of dynamic error correction based on the dynamic information di2 of the imaging unit is further enhanced.

[0108] Implementation Method 3

[0109] Figure 10 This diagram illustrates an example of the structure of the substrate measuring apparatus according to this embodiment. The substrate measuring apparatus 100b of this embodiment performs imaging when the relative speed between the imaging unit 2 and the substrate b meets a preset condition. Figure 11 This is a block diagram illustrating an example of the structure of the image processing apparatus according to this embodiment. The substrate measuring apparatus 100b of this embodiment includes an image processing apparatus 1b instead of the image processing apparatus 1 described in Embodiment 1. The image processing apparatus 1b includes an image processing unit 14b instead of the image processing unit 14 described in Embodiment 1. Structural elements, signals, etc., that are the same as or corresponding to those in Embodiment 1 are labeled with the same reference numerals as in Embodiment 1. Furthermore, the following description focuses on the differences from Embodiment 1.

[0110] The imaging processing unit 14b calculates the relative velocity V between the imaging unit 2 and the worktable 4. Based on the calculated relative velocity V, it determines whether to output a trigger signal tr. Figure 12 This is a flowchart illustrating an example of the processing of the imaging processing unit according to this embodiment. In step S301, the imaging processing unit 14b calculates the relative velocity V based on the position information pi. Here, the vibration frequency of the moving part, i.e., the worktable 4, is set as f. In addition, the center position of the hole h is measured and used as a feature point, and the diameter of the hole h is set as the hole diameter D.

[0111] Furthermore, in this embodiment, the moving part is described as the worktable 4, but this embodiment can also be applied to the substrate measuring device 100a described in Embodiment 2. In such a case, Figure 8 The speed of the imaging unit 2 is used as the relative speed V. Furthermore, for example, the vibration frequency of the worktable 4 can also be used instead. Figure 8 The vibration frequency of the x-axis stage 4a-1 and the imaging unit 2 is used as the vibration frequency f. Thus, the same effect as in this embodiment can be obtained. Here, the main body that generates vibration through the movement of the moving device is called the vibrating body. In each of the three cases—the case where the substrate b moves, the case where the imaging unit 2 moves, and the case where both the substrate b and the imaging unit 2 move—vibration may occur in both the substrate b and the imaging unit 2. Therefore, in this embodiment, it is preferable to use the stage 4 and the imaging unit 2 as the vibrating bodies.

[0112] In step S302, the imaging processing unit 14b determines whether the relative velocity V is greater than 2 × f × D. In other words, the imaging processing unit 14b determines whether the calculated relative velocity V is greater than twice the product of the vibration frequency f and the aperture D. If, in step S302, the relative velocity V is determined to be greater than 2 × f × D, the process proceeds to step S303, where the imaging processing unit 14b determines to perform imaging. Then, within a preset time period, a trigger signal tr is output every time the relative position changes by a certain distance. For example, the relative velocity V can be obtained in units of the aforementioned preset time, and the determination in step S302 can be performed each time the relative velocity V is obtained.

[0113] On the other hand, if in step S302 it is determined that the relative speed V is less than or equal to 2×f×D, the process proceeds to step S304, where the imaging processing unit 14b determines that imaging will not be performed. Then, the imaging processing unit 14b does not output the trigger signal tr for a preset time period. In both the cases of proceeding to step S303 and step S304, after the preset time has elapsed, the process returns to step S301, and the imaging processing unit 14b repeatedly executes the processing steps S301 to S304.

[0114] As explained above, in Figure 12In the processing, the substrate measuring device 100c sets a threshold for the relative speed V of the moving device. Measurement is performed when the speed exceeds the threshold, in other words, an image is captured; otherwise, no image is captured. Furthermore, the image processing unit 14b can also be applied to the substrate measuring device 100a described in Embodiment 2. Similarly, in the substrate measuring device 100a, the relative speed between the imaging unit 2 and the substrate b is set to V, and an image is captured when the relative speed V is determined to be greater than 2 × f × D, thereby achieving the same effect as the substrate measuring device 100c.

[0115] Figure 13 This is a flowchart illustrating an example of the processing by the imaging processing unit according to this embodiment. In step S311, with... Figure 12 Similar to step S301, the image processing unit 14b calculates the relative velocity V based on the position information pi. In step S312, as... Figure 12 Similar to step S302, the image processing unit 14b determines whether the relative velocity V is greater than 2×f×D. If the relative velocity V is determined to be greater than 2×f×D in step S312, the process proceeds to step S313.

[0116] Upon proceeding to step S313, similar to step S303, the image processing unit 14b outputs a trigger signal every time it moves a certain distance, in other words, every time its relative position changes by a certain distance. If, in step S312, it is determined that the relative speed V is equal to 2×f×D or less than 2×f×D, the process proceeds to step S314, in which the control unit 3 increases the moving speed of the worktable 4. Then, the process returns to step S312. Steps S312 and S314 are then repeatedly executed until, in step S312, it is determined that the relative speed V is greater than 2×f×D.

[0117] In progress Figure 13 During the action of step S314, although in Figure 11 Although not shown in the diagram, the control unit 3 can also obtain position information pi from the position measuring device 6 and calculate the relative velocity V based on the position information pi. When using... Figure 13 In the case shown, the imaging is also performed when the relative speed V is greater than 2×f×D. Furthermore, in the substrate measuring apparatus 100a described in Embodiment 2, similarly, when the relative speed V is used as the moving speed of the imaging unit 2, and the control unit 3 moves the stage 4 at a relative speed V greater than 2×f×D, the same effect as the above-described operation example is achieved.

[0118] The following explains the relationship between the measurement accuracy of the substrate measuring apparatus 100b, the diameter of the hole h, and the relative speed V. As mentioned earlier, the diameter of the hole h is set to D. Here, the diameter D is the diameter. If the relative speed V of the moving device is set to V, the time taken to acquire one image group ig of one hole is the value obtained by dividing the diameter D by the relative speed V, i.e., D / V. The vibration period of the stage 4 is set to T. In this embodiment, the vibrating body in the substrate measuring apparatus 100b that affects the measurement accuracy is the stage 4, and the vibration period of the stage 4 is used. Even if the vibrating body is not the stage 4, the same effect as in this embodiment can be obtained by appropriately using the vibration period of the vibrating body according to the structure of the vibrating body.

[0119] For example, when this embodiment is applied to the substrate measuring apparatus 100a, the moving device may select the x-axis stage 4a-1 that moves the imaging unit 2 and the imaging unit 2 as vibrating bodies, and use the vibration frequency f of the x-axis stage 4a-1 and the imaging unit 2. Alternatively, for example, the frequency of the entire substrate measuring apparatus 100b may be used as the vibrating body.

[0120] According to the sampling theorem, if the sampling frequency is greater than twice the vibration frequency f, the vibration of the worktable 4 can be measured. The time required to obtain an image group ig for one hole must be at least less than 1 / 2 of the vibration period T of the worktable 4, i.e., the sampling period. This condition is expressed by equation (1).

[0121] [Mathematical Expression 1]

[0122]

[0123] Since T = 1 / f, equation (1) can be transformed into equation (2).

[0124] [Mathematical Expression 2]

[0125] V>2fD…(2)

[0126] The dynamic correction amount dec obtained when equation (2) is satisfied is more accurate than the dynamic correction amount dec obtained when equation (2) is not satisfied. In other words, if the measurement is performed when the absolute value of the relative velocity V is greater than twice the product of the vibration frequency f of the table 4 and the aperture D, a high-precision dynamic correction amount dec can be obtained.

[0127] Here's a numerical example. Assume the aperture D is less than or equal to 100 micrometers, the relative speed V of the stage 4 is 100 millimeters per second (100 mm / s), and the vibration frequency f of the substrate measuring device 100b, which affects measurement accuracy, is 100 Hz. In this case, twice the product of the vibration frequency f and the aperture D is 20 millimeters per second (20 mm / s). Thus, when the relative speed V exceeds 20 millimeters per second (20 mm / s), a high-precision dynamic correction value dec can be calculated.

[0128] Figure 14 This diagram illustrates an example of the range of high-precision measurements that the substrate measuring apparatus according to this embodiment can perform. Figure 14 The horizontal axis represents time, and the vertical axis represents position. The solid line in the figure represents the relationship between the position of the vibrating body and time. Furthermore, the solid line represents vibration with period T and frequency f. Position can also be, for example, the positional change of a feature point caused by vibration. ΔP represents the magnitude of the positional change caused by vibration during the time period obtained by dividing the aperture D by the relative velocity V. If D / V is less than half the period, the positional change ΔP caused by vibration can be accurately calculated as a correction factor.

[0129] In one example of the substrate measuring device 100b described in this embodiment, the relative velocity V between the imaging unit 2 and the substrate b is determined. Furthermore, based on the relative velocity V, it is determined whether the imaging processing unit 14b outputs a trigger signal tr, or whether the relative velocity V is maintained at a preset range value during the imaging unit 2's imaging process.

[0130] In another example of the substrate measuring device 100b described in this embodiment, there is a control unit 3 that outputs a control signal cs. During the imaging process performed by the imaging unit 2, the control unit 3 maintains the relative speed V between the imaging unit 2 and the substrate b at a value greater than twice the product of the vibration frequency f of the vibrator and the size of the object being imaged.

[0131] In another example of the substrate measuring device 100b described in this embodiment, when the relative velocity V between the imaging unit 2 and the substrate b is greater than twice the product of the vibration frequency f of the vibrator and the size of the object being photographed, the imaging processing unit 14b outputs a trigger signal tr to perform imaging.

[0132] As described above, according to this embodiment, a substrate measuring apparatus or substrate measuring method capable of performing high-precision measurements in a short period of time can be provided. Furthermore, whether to perform imaging is determined based on the relative velocity V. Therefore, dynamic error correction can be performed with high precision, and measurements with good accuracy can be performed. Additionally, the relative velocity V between the imaging unit 2 and the substrate b can be maintained within a range that allows for accurate dynamic error correction. Therefore, measurements with good accuracy can be performed. Furthermore, since the system operates by outputting a trigger signal tr only when dynamic error correction can be performed with high precision, imaging is performed at a timing that allows for accurate measurements.

[0133] Implementation Method 4

[0134] Figure 15 This is a diagram illustrating an example of the structure of the substrate measuring device according to this embodiment. Figure 16 This is a block diagram illustrating an example of the structure of the image processing apparatus according to this embodiment. In the description of this embodiment, structural elements and signals that are the same as or correspond to those of the substrate measuring apparatus 100 described in Embodiment 1 are labeled with the same reference numerals as in Embodiment 1.

[0135] Figure 15 The substrate measuring device 100c shown has an image processing device 1c instead of an image processing device 1c. Figure 1 Image processing device 1. For example... Figure 16 As shown, the image processing apparatus 1c has a dynamic error correction calculation unit 13c instead of the dynamic error correction calculation unit 13 in Embodiment 1. Additionally, the image processing apparatus 1c has a data storage unit 15c instead of the data storage unit 15. Furthermore, in addition to the structural elements present in the image processing apparatus 1, it also has an acceleration estimation unit 18. Further, the dynamic error correction calculation unit 13c has a mechanical deformation correction calculation unit 132c instead of the mechanical deformation correction calculation unit 132 of the dynamic error correction calculation unit 13.

[0136] Except for the processing of calculating the mechanical deformation correction amount mdca, the image processing apparatus 1c of this embodiment has the same structure and operation as the image processing apparatus 1 described in Embodiment 1. Hereinafter, the processing of calculating the mechanical deformation correction amount mdca performed by the mechanical deformation correction amount calculation unit 132c will be described. The data storage unit 15c stores the substrate dynamic information di1, the imaging unit dynamic information di2, and the imaging time data id, as well as the control signal CS. Here, the control signal CS will be described as the speed or position of the stage 4. Alternatively, the data storage unit 15c may also store, for example, the control signal CS from the start to the end of the image group ig captured by the imaging unit 2.

[0137] Figure 17 This is a flowchart illustrating an example of the operation of the image processing apparatus according to this embodiment. In step S401, the acceleration estimation unit 18 calculates the command acceleration based on the control signal cs. For example, the acceleration estimation unit 18 may also determine the relative position between the substrate b and the imaging unit 2 based on the control signal cs obtained from the data storage unit 15c, and use this as the command position, and calculate the relative acceleration between the substrate b and the imaging unit 2 by performing a second derivative on the command position, thus obtaining the command acceleration. Alternatively, for example, the acceleration estimation unit 18 may determine the relative velocity between the substrate b and the imaging unit 2 based on the control signal cs, and use this as the command velocity, and calculate the command acceleration by performing a first derivative on the determined command velocity.

[0138] In step S402, the acceleration estimation unit 18 corrects for the delay time of the commanded acceleration. Here, the delay time refers to the delay of the control response of the stage 4 relative to the control signal cs. The acceleration estimation unit 18 corrects for the time delay by multiplying the delay element exhibiting responsiveness by the calculated commanded acceleration, and estimates the estimated acceleration ea. In other words, the estimated acceleration ea is the acceleration of the substrate b after time delay correction, calculated based on the control signal cs.

[0139] In step S403, the mechanical deformation correction calculation unit 132 associates the shooting time with the estimated acceleration ea. Based on the shooting time data id and the estimated acceleration ea, the mechanical deformation correction calculation unit 132 associates each shooting time of image i with the estimated acceleration ea at that shooting time. In other words, the estimated acceleration ea at the shooting time is calculated for each shooting time of image i containing feature points. Furthermore, the process of associating the shooting time with the estimated acceleration ea at the shooting time can also be performed by structural elements other than the mechanical deformation correction calculation unit 132, such as the acceleration estimation unit 18.

[0140] In step S404, the mechanical deformation correction calculation unit 132c calculates the mechanical deformation correction amount mdca based on the dynamic correction parameter dcp and the estimated acceleration ea. The mechanical deformation correction calculation unit 132c calculates the mechanical deformation correction amount mdca for each shooting moment based on the estimated acceleration ea at each shooting moment and the dynamic correction parameter dcp obtained from the dynamic correction parameter storage unit 17. Through the processing in step S404, the mechanical deformation correction amount mdca for each shooting moment of the image i containing feature points is obtained.

[0141] Except for using the estimated acceleration ea instead of the actual acceleration, the processing of the mechanical deformation correction calculation unit 132c, which calculates the mechanical deformation correction amount mdca, is the same as the operation of the mechanical deformation correction calculation unit 132 described in Embodiment 1. For example, the mechanical deformation correction calculation unit 132c may also be based on a model that generates a mechanical deformation error proportional to the estimated acceleration ea in the deformed object, and use the value obtained by multiplying the dynamic correction parameter dcp by the estimated acceleration ea at each shooting time as the mechanical deformation correction amount mdca at each shooting time. In this case, the dynamic correction parameter dcp is a proportionality coefficient between the estimated acceleration ea and the mechanical deformation correction amount mdca.

[0142] Furthermore, the mechanical deformation correction calculation unit 132c can also calculate the mechanical deformation for pitch and yaw separately, just like the mechanical deformation correction calculation unit 132, and combine them as the mechanical deformation correction amount mdca. In addition, similar to the dynamic error correction calculation unit 13, the vibration correction calculation unit 131 can be omitted in the dynamic error correction calculation unit 13c, and the dynamic error correction amount dec can be calculated only based on the mechanical deformation correction amount mdca.

[0143] Furthermore, the processing of the substrate measuring apparatus 100c can also be applied to the substrate measuring apparatus 100a described in Embodiment 2. When applied to the substrate measuring apparatus 100a, in the substrate measuring apparatus 100a, except... Figure 9 In addition to the structure, it also has an acceleration estimation unit 18. Furthermore, it can perform the same processing as the mechanical deformation correction amount calculation unit 132c described in this embodiment, replacing the processing performed by the mechanical deformation correction amount calculation unit 132. In other words, the acceleration estimation unit 18 only needs to calculate the estimated acceleration ea based on the control signal cs of the control unit 3a.

[0144] Furthermore, the processing of the substrate measuring apparatus 100c can also be applied to the substrate measuring apparatus 100b described in Embodiment 3. For example, in the substrate measuring apparatus 100b, it is also possible to remove... Figure 11In addition to the structure, it also has an acceleration estimation unit 18, which performs the same processing as the mechanical deformation correction amount calculation unit 132c described in this embodiment, instead of the processing performed by the mechanical deformation correction amount calculation unit 132. Furthermore, the relative velocity between the imaging unit 2 and the substrate b can be calculated, and the imaging processing unit 14b determines whether to output a trigger signal tr based on the relative velocity. Alternatively, the relative velocity between the imaging unit 2 and the substrate b can be calculated, and the relative velocity can be maintained at a preset range value during imaging by the imaging unit 2. Additionally, for example, the imaging processing unit 14b can output the trigger signal tr only when equation (2) is satisfied. Furthermore, the speed of the moving device can be controlled in a manner that satisfies equation (2).

[0145] As described above, in one example of the substrate measuring device 100c of this embodiment, there is an acceleration estimation unit 18 that estimates the relative acceleration between the imaging unit 2 and the substrate b based on the control signal sc, and the dynamic error correction calculation unit 13 has a mechanical deformation correction calculation unit 132c. The mechanical deformation correction calculation unit 132c calculates the mechanical deformation correction amount mdca based on the estimated acceleration ea and the dynamic error correction parameter dcp.

[0146] According to the substrate measuring device 100c, the acceleration estimation unit 18 calculates the estimated acceleration ea based on the control signal CS. Therefore, with the acceleration and deceleration of the stage 4, the measurement error caused by the mechanical deformation of the stage 4 due to inertial force can be estimated. Furthermore, the mechanical deformation correction calculation unit 132c calculates the mechanical deformation correction amount mdca based on the estimated acceleration ea, the dynamic correction parameter dcp, the provisional coordinate pc, and the shooting time data id. Therefore, the dynamic error correction calculation unit 13 and the dynamic error correction calculation unit 13a can calculate the dynamic correction amount dec in the same way as when the dynamic error correction amount dec is calculated based on the dynamic information di. In addition, as in the case where the dynamic information di is obtained by the dynamic information acquisition unit 5, it is not affected by the noise of the sensor, so a high-precision estimation of relative acceleration can be achieved.

[0147] Furthermore, by correcting the provisional coordinate pc based on the dynamic correction amount dec in the measurement processing unit 16, even if the worktable 4 is in a state of mechanical deformation during the imaging unit 2's imaging, a measurement result corrected for the measurement error caused by the aforementioned mechanical deformation can be obtained. In other words, the dynamic information di is sometimes affected by the mechanical deformation generated in the worktable 4, etc. On the other hand, the estimated acceleration ea in this embodiment is a value that is not affected by mechanical deformation, so the dynamic error correction amount dec can be calculated more accurately.

[0148] As described above, according to this embodiment, a substrate measuring apparatus or substrate measuring method capable of performing high-precision measurements in a short period of time can be provided.

[0149] Implementation Method 5

[0150] Figure 18 This is a diagram illustrating an example of the structure of the substrate measuring device according to this embodiment. Figure 19 This is a block diagram illustrating an example of the structure of the image processing apparatus according to this embodiment. In the description of this embodiment, structural elements and signals that are the same as or correspond to those of the substrate measuring apparatus 100 described in Embodiment 1 are labeled with the same reference numerals as in Embodiment 1.

[0151] Figure 18 The substrate measuring device 100d shown has an image processing device 1d instead. Figure 1 Image processing apparatus 1d. Image processing apparatus 1d has a measurement processing unit 16d instead of the measurement processing unit 16 in embodiment 1. In addition, image processing apparatus 1d has an image processing unit 14d instead of the image processing unit 14. Image processing unit 14d has an image residual calculation unit 141 for calculating the image residual re. In addition, it has an image residual storage unit 142 for storing the calculated image residual re. Hereinafter, the differences between image processing apparatus 1d and image processing apparatus 1d will be described.

[0152] Figure 20 This is a flowchart illustrating an example of the operation of the image processing apparatus according to this embodiment. In step S501, the shooting residual calculation unit 141 calculates the shooting residual re based on the dynamic error correction amount dec. An example is shown of the process of calculating the shooting residual re at each shooting time. The shooting residual calculation unit 141 calculates the positional deviation between the target shooting position and the position information pi at the shooting time as the shooting position deviation Δp. Further, the dynamic error correction amount dec is obtained from the dynamic error correction amount calculation unit 13. And, the shooting residual re is calculated based on the shooting position deviation Δp and the dynamic error correction amount dec.

[0153] The following example illustrates the process for calculating the shooting position deviation Δp. The position of the mobile device at each moment is designated as the command position via the control signal cs. Furthermore, the command position at each shooting moment is set as the target shooting position. The difference between the position information pi at each shooting moment and the aforementioned target shooting position is taken as the shooting position deviation Δp. This is an example of the process for calculating the shooting position deviation Δp.

[0154] For example, the imaging residual calculation unit 141 is a unit with... Figure 19The shooting position deviation Δp and dynamic error correction amount dec are obtained by taking the vectors of the x-axis and y-axis components. Furthermore, the shooting residual re can also be calculated as the sum of the shooting position deviation Δp and the dynamic error correction amount dec. In this case, the shooting residual re is a vector having x-axis and y-axis components. The above is an example of the processing in step S501.

[0155] In step S502, the imaging processing unit 14d outputs a trigger signal based on the imaging residual re. For example, based on one or more acquired imaging residuals re, the imaging residual re1 at time t1 after the time when the imaging residual re was acquired is estimated. Furthermore, the time of the output trigger signal tr can be varied relative to time t1 so that the imaging residual re at the time of the output trigger signal tr is smaller than the estimated imaging residual re1. Alternatively, the time of the output trigger signal tr1 can be varied relative to time t1 so that the imaging position approaches the target position by an amount equivalent to the imaging residual re1. The time equivalent to the imaging residual re1 refers to the time for compensating for positional deviations of the amount of the imaging residual re1.

[0156] For example, at time t1, if it is determined, based on the estimated value of the shooting residual re1, that the movement of the relative position between the substrate b and the imaging unit 2 is delayed relative to the target shooting position by a distance Δl, the timing of issuing the trigger signal tr is advanced by using the value obtained by dividing Δl by the relative velocity v. In this case, Δl / v becomes the time equivalent to the shooting residual re. Here, the relative velocity v is the relative velocity between the substrate b and the imaging unit 2.

[0157] In step S503, the shooting residual calculation unit 141 associates the shooting time with the shooting residual re using the shooting time data id. For example, the shooting processing unit 14d may also associate the shooting time with the shooting residual re at that shooting time using the location information pi and the shooting time data id. In step S504, the shooting residual re associated with the shooting time is stored in the shooting residual storage unit 142.

[0158] In step S505, the provisional coordinate pc is corrected based on the shooting residual re and the static error correction amount sec, and output as the measurement result mr. For example, the measurement processing unit 16d may also associate the static error correction amount and the shooting residual re with the provisional coordinate pc via the shooting time, and perform correction on each provisional coordinate.

[0159] For example, the measurement processing unit 16d obtains the shooting residual re, which has components in the x-axis and y-axis directions, from the shooting residual storage unit 142. Furthermore, the measurement processing unit 16d obtains the static error sec, which has components in the x-axis and y-axis directions, from the static error correction calculation unit 11. The measurement result mr can also be calculated by subtracting the shooting residual re and the static error sec from the provisional coordinate pc.

[0160] The structure described in this embodiment can also be applied to the substrate measuring apparatus described in embodiments 2 to 4. That is, in the measurement processing units of substrate measuring apparatus 100a, substrate measuring apparatus 100b, and substrate measuring apparatus 100c, the shooting residual re can be used to calculate the measurement result mr instead of the dynamic error correction amount dec. In addition, in substrate measuring apparatus 100d, the shooting residual re calculated by the shooting residual calculation unit 141 is temporarily stored in the shooting residual storage unit 142, but the shooting residual storage unit 142 can also be omitted. Furthermore, the measurement processing unit 16d can also be structured to directly obtain the shooting residual re from the shooting residual calculation unit 141.

[0161] As described above, in one example of the substrate measuring apparatus 100d according to this embodiment, the image processing unit 14d includes an image residual calculation unit 141. The image residual calculation unit 141 calculates the deviation between the target image position and the image position based on the dynamic error correction amount dec, and uses this as the image residual re. The image processing unit 14d outputs a trigger signal tr based on the image residual re, and the measurement processing unit 16d corrects the provisional coordinate pc based on the image residual re and calculates the measurement result mr.

[0162] Here, the measurement processing unit 16d can also output a trigger signal after the aforementioned time based on the shooting residual re calculated at a certain time. Alternatively, it can estimate the shooting residual re1 at time t1 after the aforementioned time based on the shooting residual re at a certain time, and change the time of the output trigger signal tr relative to time t1 in such a way that the shooting residual re at the time of output trigger signal tr is smaller than the estimated shooting residual re1, thereby determining the time of output trigger signal tr. This reduces the deviation between the target shooting position and the shooting position.

[0163] As described above, according to this embodiment, a substrate measurement apparatus or substrate measurement method capable of performing high-precision measurements in a short period of time can be provided. Furthermore, by calculating the shooting residual *re* as the deviation of the shooting position from the target shooting position, and outputting a trigger signal *tr* based on the shooting residual *re*, the positional deviation between the target shooting position and the actual shooting position can be corrected based on the dynamic error correction amount *dec*. Therefore, high-precision shooting can be performed. Additionally, by correcting the provisional coordinate *pc* using the shooting residual *re*, the accuracy of the measurement result *mr* can be improved in the same way as the substrate measurement apparatus described in embodiments 1 to 4.

[0164] Explanation of the label

[0165] 1. Image processing device (1a, 1b, 1c, 1d); 2. Imaging unit; 3. Control unit (3a); 4. Worktable (4a); 5. Dynamic information acquisition unit; 6. Position measuring device (6a); 10. Image processing unit; 11. Static error correction calculation unit; 12. Static error correction parameter storage unit; 13. Dynamic error correction calculation unit (13a, 13c); 14. Imaging processing unit (14a, 14b, 14d); 15. Data storage unit (15c); 16. Measurement processing unit (16d); 17. Dynamic correction parameter storage unit; 18. Acceleration estimation unit; 31. 31a X-axis controller, 32 Y-axis controller, 100, 100a, 100b, 100c, 100d substrate measuring devices, 131 vibration correction calculation unit, 132, 132c mechanical deformation correction calculation units, 141 image residual calculation unit, 142 image residual storage unit, 10001 processor, 10002 memory, 10003 processing circuit, b substrate, CS control signal, dcp dynamic error correction parameter, dc dynamic correction amount, dec dynamic error correction amount, di1 substrate dynamic information, di2 image unit dynamic information, e edge detection point, f vibration frequency, h hole, is image signal, id image time data, mr measurement result, pc provisional coordinates, pi position information, re image residual, sec static error correction amount, sp static residual correction parameter, tr trigger signal.

Claims

1. A substrate measuring device, characterized in that, have: The image processing unit outputs a trigger signal; The imaging unit captures images of the substrate based on the trigger signal and outputs information of multiple images, i.e., image groups, as image signals. A mobile device that changes the relative position between the substrate and the imaging unit based on control signals; The image processing unit calculates the real-space position coordinates of the feature points captured in the image based on the image signal and outputs them as provisional coordinates. An acceleration sensor is provided in at least one of the following two cases: that is, the acceleration sensor is provided on the worktable on which the substrate is placed to measure the acceleration of the substrate when it is moved by the moving device; or, the acceleration sensor is provided on the imaging unit to measure the acceleration of the imaging unit when it is moved by the moving device. The dynamic error correction calculation unit calculates a dynamic error correction amount based on at least one of the acceleration of the substrate or the acceleration of the imaging unit when the moving device moves. The dynamic error correction calculation unit includes a vibration correction calculation unit, which performs at least one of the following: calculating the position change of the substrate caused by the vibration of the substrate, i.e., the substrate vibration position, based on the acceleration of the substrate; or calculating the position change of the imaging unit caused by the vibration of the imaging unit, i.e., the imaging unit vibration position, based on the acceleration of the imaging unit. as well as The measurement processing unit corrects the provisional coordinates based on the dynamic error correction amount and outputs the measurement result as the position coordinates of the feature point in real space. The dynamic error correction calculation unit performs at least one of the following calculations: The dynamic error correction amount is calculated based on the vibration position of the substrate calculated according to the acceleration of the substrate during the capture of the image group including the provisional coordinates. Alternatively, the dynamic error correction amount is calculated based on the vibration position of the imaging unit, which is calculated according to the acceleration of the imaging unit during the capture of the image group including the provisional coordinates.

2. The substrate measuring device according to claim 1, characterized in that, The moving device moves only the substrate based on the control signal, thereby changing the relative position. The acceleration sensor is only located on the imaging unit to measure the acceleration of the imaging unit.

3. The substrate measuring device according to claim 1, characterized in that, When the substrate moves via the moving device, the vibration correction calculation unit calculates the vibration position of the substrate based on the acceleration of the substrate obtained by the acceleration sensor provided on the worktable, as well as the acceleration of the substrate calculated according to the control signal. When the imaging unit moves via the moving device, the vibration correction calculation unit calculates the vibration position of the substrate using the acceleration of the imaging unit calculated based on the control signal, in addition to the acceleration of the imaging unit obtained by the acceleration sensor provided on the imaging unit.

4. The substrate measuring device according to claim 1, characterized in that, The dynamic error correction calculation unit performs at least one of the following processes: The acceleration of the substrate, measured by the accelerometer installed on the worktable at the moment the image containing the provisional coordinates is captured, is used as the acceleration of the substrate during the capture of the image set containing the provisional coordinates. Alternatively, the acceleration of the imaging unit, measured by the accelerometer provided on the imaging unit at the moment of shooting the image containing the provisional coordinates, can be obtained as the acceleration of the imaging unit when shooting the image group containing the provisional coordinates.

5. The substrate measuring apparatus according to any one of claims 1 to 4, characterized in that, The accelerometer performs at least one of the following processes: obtaining the acceleration of the substrate in the x-axis direction, which is the direction in which the relative position changes due to the movement of the moving device during the capture of the image group, and the acceleration of the substrate in the y-axis direction, which is perpendicular to the direction in which the relative position changes during the capture of the image group; or, obtaining the acceleration in the x-axis direction and the acceleration in the y-axis direction of the capturing unit. The vibration correction calculation unit performs at least one of the following processes: calculating the vibration position of the substrate in the x-axis direction based on the acceleration of the substrate in the x-axis direction, and calculating the vibration position of the substrate in the y-axis direction based on the acceleration of the substrate in the y-axis direction; or calculating the vibration position of the imaging unit in the x-axis direction based on the acceleration of the imaging unit in the x-axis direction, and calculating the vibration position of the imaging unit in the y-axis direction based on the acceleration of the substrate in the y-axis direction. The dynamic error correction calculation unit calculates the dynamic error correction amount in the x-axis direction based on at least one of the vibration position of the substrate in the x-axis direction or the vibration position of the imaging unit in the x-axis direction. The dynamic error correction calculation unit calculates the dynamic error correction amount in the y-axis direction based on at least one of the vibration position of the substrate in the y-axis direction or the vibration position of the imaging unit in the y-axis direction. The measurement processing unit corrects the coordinates of the provisional coordinates in the x-axis direction using the dynamic error correction amount in the x-axis direction, and corrects the coordinates of the provisional coordinates in the y-axis direction using the dynamic error correction amount in the y-axis direction.

6. The substrate measuring apparatus according to any one of claims 1 to 4, characterized in that, The dynamic error correction calculation unit includes a mechanical deformation correction calculation unit, which performs at least one of the following calculations: calculating the displacement caused by the mechanical deformation of the substrate, i.e., the substrate-side mechanical deformation, based on the acceleration of the substrate; or calculating the displacement caused by the mechanical deformation of the imaging unit, i.e., the imaging unit-side mechanical deformation, based on the acceleration of the imaging unit. The dynamic error correction calculation unit calculates the dynamic error correction amount based on at least one of the mechanical deformation on the substrate side or the mechanical deformation on the imaging side, and the dynamic correction parameters. The mechanical deformation correction calculation unit performs at least one of the following calculations: calculating the mechanical deformation on the substrate side based on the acceleration of the substrate during the capture of the image group including the provisional coordinates, or calculating the mechanical deformation on the imaging part side based on the acceleration of the imaging part during the capture of the image group including the provisional coordinates.

7. The substrate measuring apparatus according to any one of claims 1 to 4, characterized in that, The imaging unit is a line scan camera. While changing the relative position between the substrate and the imaging unit in a direction perpendicular to the arrangement direction of the plurality of imaging elements of the line scan camera, the imaging unit performs imaging. The imaging processing unit outputs the trigger signal in a manner that keeps the magnitude of the change in the relative position between the substrate and the imaging unit constant between two consecutive imaging sessions.

8. The substrate measuring apparatus according to any one of claims 1 to 4, characterized in that, It also includes a static error correction calculation unit, which calculates a correction amount, i.e., a static error correction amount, for the measurement error generated when the mobile device is stationary and there is no residual vibration caused by the mobile device, based on static error correction parameters. The measurement processing unit calculates the measurement result based on the static error correction amount.

9. The substrate measuring apparatus according to any one of claims 1 to 4, characterized in that, The relative speed between the imaging unit and the substrate is determined, and the imaging processing unit decides whether to output the trigger signal based on the relative speed, or to maintain the relative speed at a preset range during the imaging process performed by the imaging unit.

10. The substrate measuring apparatus according to claim 9, characterized in that, The control unit has a control unit that outputs the control signal. During the shooting process performed by the shooting unit, the control unit maintains the relative speed between the shooting unit and the substrate at a value greater than twice the product of the vibration frequency of the vibrating body and the size of the shooting object constituting the contour line, edge, or region used to determine the coordinates of the feature point. The vibrating body includes at least one of the worktable and the shooting unit.

11. A substrate measurement method, wherein in the substrate measurement method, Output trigger signal, The imaging unit captures images of the substrate based on the trigger signal, and outputs information from multiple images, i.e., image groups, as image signals. The relative position between the substrate and the imaging unit is changed by a moving device based on a control signal. Based on the image signal, the real-space coordinates of the feature points captured in the image are calculated and output as provisional coordinates. Perform at least one of the following processes: measure the acceleration of the substrate during movement by the moving device using an accelerometer provided on the worktable on which the substrate is placed; or measure the acceleration of the imaging unit during movement by the moving device using an accelerometer provided on the imaging unit. The dynamic error correction amount is calculated based on at least one of the acceleration of the substrate or the acceleration of the imaging unit during the movement of the mobile device. Perform at least one of the following calculations: calculate the positional change of the substrate caused by the vibration of the substrate, i.e., the substrate vibration position, based on the acceleration of the substrate; or calculate the positional change of the imaging unit caused by the vibration of the imaging unit, i.e., the imaging unit vibration position, based on the acceleration of the imaging unit. The provisional coordinates are corrected based on the dynamic error correction amount, and the result is output as the measurement result of the position coordinates of the feature point in the real space. When calculating the dynamic error correction amount, at least one of the following calculations is performed: The acceleration of the substrate during the capture of the image group including the provisional coordinates is determined. Based on the vibration position of the substrate calculated according to the determined acceleration, the dynamic error correction amount is calculated. Alternatively, the acceleration of the imaging unit during the capture of the image group including the provisional coordinates is determined, and the dynamic error correction amount is calculated based on the vibration position of the imaging unit calculated according to the determined acceleration of the imaging unit.

Images