JP3602965B2 - Non-contact three-dimensional measurement method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a non-contact image measurement function for measuring a contour shape or the like of an object to be measured from an image obtained by imaging a work by an imaging means such as a CCD camera, and a non-contact image measurement function that uses a distance from a measurement surface of the work as a displacement. The present invention relates to a non-contact three-dimensional measuring method which is effective when measuring a precision component such as an IC package using a non-contact three-dimensional measuring device having a non-contact displacement detecting function for detecting contact.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an image measuring device has been used for measuring a contour shape of a precision part. The image measurement device captures an image of a workpiece to be measured at an arbitrary magnification using a CCD camera, detects edges from the obtained two-dimensional image, and obtains coordinate values of a necessary portion using various measurement tools. Things. When three-dimensional measurement including the height direction of the work is performed by the image measurement device, focus determination is performed based on the contrast of the image on the measurement surface, and the focus position is set as a position in the height direction.
[0003]
[Problems to be solved by the invention]
In a mounted component having a fine structure such as an LSI package, the manufacturing quality of the package is a major factor that determines the yield. For this reason, a device that can measure each part of the package with high accuracy is desired. In the conventional image measuring device, the position in the height direction (Z-axis direction) is measured by autofocus, so that there is a restriction that a portion to be measured must be parallel to the XY plane. What is measured by focus is only the average value of the set area. Therefore, it was not possible to measure the contour shape or the surface roughness such as to measure fine irregularities in the Z-axis direction.
[0004]
The present invention has been made in view of such a point, and provides a non-contact three-dimensional measuring method in which a measuring part of a work is inclined, or three-dimensional measurement can be performed with high accuracy with fine irregularities. Aim.
[0005]
[Means for Solving the Problems]
The non-contact three-dimensional measurement method according to the present invention includes an imaging unit that captures an image of a workpiece and outputs two-dimensional image information for image measurement, and a non-contact three-dimensional measurement method that can detect a distance from a predetermined measurement point on the workpiece as a displacement amount. A non-contact three-dimensional measurement method for obtaining three-dimensional point sequence data by moving an imaging unit having a contact displacement meter and a measurement three-dimensional space, wherein the workpiece is image-measured using the imaging means. Confirming the position of the three-dimensional point sequence by moving the non-contact displacement meter to a predetermined measurement start point based on this position, and then performing scanning measurement along a specified measurement trajectory. A step of acquiring data, a step of performing a trend correction on the point sequence data obtained in this step, and a step of converting the three-dimensional data corrected in this step into two-dimensional data. And-up, the steps of applying a constant pitch processing in a two-dimensional data obtained in this step, characterized by comprising the step of applying a filtering process on the two-dimensional data constant pitch in this step.
[0006]
According to the present invention, since the non-contact displacement meter follows and measures the displacement of the work along the specified measurement trajectory using the two-dimensional image information obtained by the imaging means, even if the work is inclined, The influence on the measurement accuracy is small, and high-accuracy three-dimensional point sequence data can be obtained. By performing the trend correction on the three-dimensional point sequence data, the subsequent processing is simplified. Further, according to the present invention, since the obtained data is three-dimensional point sequence data, it is conceivable that filter processing or the like may be difficult. The original data is converted to two-dimensional data and subjected to constant pitch processing. Therefore, according to the present invention, it is easy to execute predetermined analysis processing such as analysis of fine irregularities in the Z-axis direction, contour shape analysis, and surface roughness analysis using the filtered two-dimensional data.
[0007]
For example, when only filtering is performed on the obtained point sequence data, a step of returning the filtered two-dimensional data to the original pitch, and a step of returning the two-dimensional data to the original pitch in this step To the three-dimensional data, and a step of performing an inverse trend correction on the three-dimensional data obtained in this step. Can be obtained.
[0008]
Further, the method may further include a step of performing an arbitrary analysis process on the two-dimensional data on which the filter process has been performed. For example, when measuring the flatness of a land grid array or a ball grid array of a workpiece made of an IC package, a step of extracting data of a plurality of vertexes or valleys of the filtered two-dimensional data, Converting the data extracted in the step from two-dimensional data to three-dimensional data, and calculating the flatness of the land grid array or ball grid array from the three-dimensional data obtained in this step. do it.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing an entire configuration of a non-contact three-dimensional measuring device according to one embodiment of the present invention.
This apparatus includes a three-dimensional measuring machine 1 having a non-contact image measuring function and a non-contact displacement measuring function, and a computer system 2 for controlling the driving of the three-dimensional measuring machine 1 and executing necessary data processing. It is configured.
[0010]
The coordinate measuring machine 1 is configured as follows. That is, a measurement table 13 on which the work 12 to be measured is placed is mounted on the gantry 11, and the measurement table 13 is driven in the Y-axis direction by a Y-axis drive mechanism (not shown). Support arms 14 and 15 extending upward are fixed to the center of both side edges of the gantry 11, and an X-axis guide 16 is fixed so as to connect both upper ends of the support arms 14 and 15. An imaging unit 17 is supported by the X-axis guide 16. The imaging unit 17 is driven along the X-axis guide 16 by an X-axis driving mechanism (not shown). The computer system 2 includes a computer 21 for performing measurement information processing and various controls, a keyboard 22, a joystick box 23 and a mouse 24 for inputting various instruction information, a CRT display 25 for displaying a measurement screen, an instruction screen, and a measurement result. And a printer 26 for printing out the measurement results.
[0011]
The inside of the imaging unit 17 is configured as shown in FIG. That is, the slider 31 is provided movably along the X-axis guide 16, and the Z-axis guide 32 is fixed to the slider 31 integrally. A support plate 33 is slidably provided in the Z-axis guide 32 in the Z-axis direction. The support plate 33 has a CCD camera 34 as an image pickup means for image measurement and a laser probe as a non-contact displacement meter. 35 are provided side by side. Thus, the CCD camera 34 and the laser probe 35 can be simultaneously moved in the X, Y, and Z axes while maintaining a fixed positional relationship. An illumination device 36 for illuminating the imaging range is added to the CCD camera 34. In the vicinity of the laser probe 35, a CCD camera 38 for imaging the periphery of the measurement position to confirm the measurement position of the laser probe 35 by the laser beam, and an illumination device 39 for illuminating the measurement position of the laser probe 35 Are provided. The laser probe 35 is supported by a vertical movement mechanism 40 for retracting the laser probe 35 when the imaging unit 17 moves, and a rotation mechanism 41 for adjusting the directionality of the laser beam to an optimal direction. .
[0012]
FIG. 3 is a diagram showing details of the laser probe 35.
The light emitted from the semiconductor laser 51 passes through a beam splitter 52 and a quarter-wave plate 53, is converted into a parallel light beam by a collimator lens 54, and passes through mirrors 55 and 56 and an objective lens 57 to measure the work 12. To form a light spot. The light reflected from the measurement section of the work 12 is reflected by the beam splitter 52 along a reverse path of the mirrors 56 and 55, the collimator lens 54 and the quarter-wave plate 53, and is vertically split by the edge mirror 58. . The vertically split light is detected by the vertically split light receiving elements 59 and 60. The detection circuit 61 outputs a signal corresponding to the amount of deviation from the focal position of the objective lens 57 to the measurement surface 62 of the workpiece 12 based on the output signals from the two-divided light receiving elements 59 and 60. The servo circuit 63 outputs a drive signal for driving the objective lens 57 to the drive mechanism 64 based on the detection output of the detection circuit 61. When the objective lens 57 moves up and down, the movable member 67 of the displacement detector 66 moves with respect to the fixed member 68. This movement amount is output as a displacement amount.
[0013]
FIG. 4 is a block diagram of the entire apparatus showing the configuration of the coordinate measuring machine 1 and the computer system 2 in more detail.
In the coordinate measuring machine 1, image signals obtained by imaging the work 12 with the CCD camera 34 for image measurement and the CCD camera 35 for confirming the measurement position of the laser probe 35 are converted into A / D converters 71 and 72, respectively. Is converted into multi-valued image data by the selector, and one of them is selected by the selection circuit 73 and supplied to the computer 21. Illumination light necessary for imaging by the CCD cameras 34 and 38 is given by the illumination control units 74 and 75 controlling the illumination devices 36 and 39, respectively, under the control of the computer 21. The signal of the displacement amount obtained from the laser probe 35 is supplied to the computer 21 via the A / D converter 76. Then, the imaging unit 17 including these is driven in the XYZ-axis directions by the XYZ-axis driving unit 77 that operates based on the control of the computer 21. The position of the imaging unit 17 in the XYZ-axis direction is detected by the XYZ-axis encoder 78 and supplied to the computer 21.
[0014]
On the other hand, the computer 21 has a central processing unit (CPU) 81, a multi-valued image memory 82, a program storage unit 83, a work memory 84, interfaces 85 and 86 connected to the CPU 81, and a multi-valued image memory 81. A display control unit 87 for displaying the multi-valued image data on the CRT display 25. The CPU 81 switches the selection circuit 73 between the image measurement mode and the laser measurement mode. The multivalued image data for image measurement or the multivalued image data for laser measurement selected by the selection circuit 73 is stored in the multivalued image memory 82. The multivalued image data stored in the multivalued image memory 82 is displayed on the CRT display 25 by the display control operation of the display control unit 87. On the other hand, operator's instruction information input from the keyboard 22, the joystick 23 and the mouse 24 is input to the CPU 81 via the interface 85. Further, the CPU 81 captures the displacement amount detected by the laser probe 35, the XYZ coordinate information from the XYZ axis encoder 78, and the like. The CPU 81 executes various processes such as stage movement by the XYZ-axis driving unit 77 and arithmetic processing of measured values, based on the input information, the instructions of the operator, and the programs stored in the program storage unit 83. The work memory 84 provides a work area for various processes of the CPU 81. The measured values are output to the printer 26 via the interface 86.
[0015]
Next, measurement processing and data processing of the non-contact three-dimensional measuring apparatus according to the present embodiment configured as described above will be described. This device has an image measurement mode and a laser measurement mode. In the image measurement mode, the same operation as that of the conventional image measurement device is performed. Therefore, the laser measurement mode will be described here.
[0016]
FIG. 5 is a flowchart showing a procedure of scanning measurement in the laser measurement mode. First, calibration of the image for image measurement and the laser probe 35 is performed (S1). That is, a jig 91 including two non-parallel linear components L1 and L2 that can be measured by the CCD camera 34 and the laser probe 35 as shown in FIG. 6 is placed on the stage 13 of the coordinate measuring machine 1. The jig 91 may be, for example, such that a trapezoidal pattern 93 having a predetermined width h is arranged on a substrate 92. The CCD camera 34 and the laser probe 35 measure the straight lines L1 and L2 in the projection plane in the Z-axis direction by the CCD camera 34 and the laser probe 35, obtain the equations of these straight lines, and calculate the obtained equations. An offset value between the coordinate axes 35 is obtained, and this offset value is used as position calibration data of the CCD camera 34 and the laser probe 35.
[0017]
When the calibration processing is completed, next, the position of the work 12 is confirmed by measuring the image of the work 12, and the measurement point by the laser probe 35 is moved to the measurement start point (S2). At the time of image measurement, the laser probe 35 may interfere with the work 12. Therefore, during image measurement, the laser probe 35 is retracted upward by the vertical movement mechanism 40. The control is performed by, for example, an air cylinder. Next, when the laser measurement mode is selected (S3), the selection circuit 73 is switched, and the screen of the CRT display 25 changes from the CCD camera 34 to the screen of the CCD camera 38 for laser measurement. On this screen, the position (measurement position) of the laser beam spot from the laser probe 36 is confirmed (S4). Here, the position of the beam spot can be finely adjusted using the joystick 23, the mouse 24, or the like. Since the CCD camera 38 is for confirming whether or not the laser beam spot is correctly hitting the target position on the work 12, the image data is not used for the measurement. For this reason, it is not necessary to have a high-definition camera like the CCD camera 34 for image measurement. Further, only the position of the laser spot looks bright only with the laser light, and the surrounding area becomes dark, so that a clear image cannot be obtained. Of course, the CCD camera 38 and the illuminating device 39 can also be used as the CCD camera 34 and the illuminating device 36.
[0018]
Next, a measurement tool is selected and necessary parameters are set to provide a path for scanning measurement (S5). As the measurement tool, for example, the one shown in FIG. 7 can be considered.
(A) Point tool
The X, Y, and Z coordinate values of the current measurement point (black circle) are measured.
(B) Straight line tool
Given the end point position Pe, measurement is performed along a straight line from the current measurement point to the end point Pe.
(C) Area tool
Given the width W, height H, and pitches PT1 and PT2 of the area search, scanning measurement is performed while reciprocating within the specified area at the specified pitch from the current measurement point.
(D) Circle tool
Given a radius R, a pitch PT, and a start angle θ, the measurement is performed on a concentric circle from the current measurement point.
(E) Rectangular tool
Given a width W and a height H, the scanning measurement is performed along a rectangle.
(F) Cross tool
Given the lengths L1 and L2 of two line segments orthogonal to each other, the measurement is performed while following the cross.
(G) Spiral tool
Given a maximum radius R and a pitch RT (radius value that increases in one rotation), a spiral measurement is performed.
(H) Focus tool
Just focus on the current position.
[0019]
When a measurement tool is selected and necessary parameters are set, scanning measurement is executed (S6). The displacement detection accuracy of the laser probe 35 has some directionality. For this reason, when measuring the contour and the surface roughness along the track, the laser probe 35 is rotated by the rotating mechanism 41 so that the laser probe 35 is oriented in the optimum direction with respect to the direction of the track. When measuring along a circular orbit or a spiral orbit, it is more effective to measure while rotating the laser probe 35.
[0020]
At the time of scanning measurement, the displacement amount from the laser probe 35 is, for example, as shown in FIG. The XYZ-axis driving unit 77 is driven based on this, and the position of the imaging unit 17 in the Z-axis direction is moved up and down. Thereby, control is performed such that the focus position of the laser probe 35 is always at the center of the measurement range. In this case, the Z-axis coordinate value obtained by the XYZ-axis encoder 78 is the displacement amount in the Z-axis direction. In order to perform high-speed measurement in which the position control in the Z-axis direction cannot be performed in time, it is only necessary to correct the Z-axis coordinate value with the displacement amount of the laser probe 35 and calculate a correct displacement amount. When measuring the minute surface roughness within the measurement range of the laser probe 35, as shown in FIG. 9, the position of the laser probe 35 in the Z-axis direction is fixed, and the objective lens 57 in the laser probe 35 is fixed. In this case, it is possible to perform processing at a higher speed and to measure at a higher resolution (eg, 0.01 μm) than the resolution (eg, 0.1 μm) by Z-axis driving. Become. By such scanning measurement, coordinate values in the Z-axis direction are obtained as point sequence data along with the X- and Y-axis coordinate values at predetermined intervals along a designated measurement trajectory, and are stored in the work memory 84. When the point sequence data is obtained, an analysis process of the point sequence data is executed (S7).
[0021]
Next, an analysis process of the point sequence data will be described. A conventional contour shape measuring device and a surface roughness measuring device are two-dimensional data, whereas the contour shape measuring data obtained by this non-contact three-dimensional measuring device is three-dimensional data. In addition, since the scanning measurement is performed along the designated two-dimensional trajectory, data processing becomes more complicated. Therefore, in order to simplify the data processing, the following point string data analysis processing is executed. The analysis process of this point sequence data will be described based on the flowchart of FIG. 10 and the waveform diagram of FIG.
[0022]
First, since the work 12 itself may be inclined, an average plane (an average line in the case of a straight line) is obtained from the point sequence data, and data trend correction is performed on this plane (S11). Thereby, the trend-corrected point sequence data shown in FIG. 11B is obtained from the inclined point sequence data as shown in FIG. Next, three-dimensional point sequence data is converted into two-dimensional point sequence data with the traveling direction along the measurement trajectory being the first axis direction and the normal direction of the average plane being the second axis direction (S12). As a result, data as shown in FIG. 11C is obtained. Since this point sequence data is obtained by scanning with acceleration / deceleration along the measurement trajectory, it is not a constant pitch. If the pitch is not constant, Gaussian (Gaussian) filter processing generally used in an FFT (Fast Fourier Transform) or a shape measuring instrument cannot be executed. Therefore, a constant pitch processing is executed here (S13: FIG. 11 ( d)). Next, Gaussian filter processing is executed (S14: FIG. 11E). Then, the fixed pitch data is returned to the original position (position of an unfixed pitch) (S15: FIG. 11 (f)). Next, two-dimensional to three-dimensional conversion for returning the two-dimensional data converted in step S12 to the original measurement trajectory position (XY position) is executed (S16: FIG. 11 (g). The inclination correction performed by the data trend correction in S11 is restored, and the data is converted in the direction in which the work 12 is originally inclined (S17: FIG. 11H).
[0023]
With the above processing, filtering of the three-dimensional point sequence data can be easily performed. Further, since the data after the processing in step S14 is two-dimensional data filtered at a constant pitch, various analysis processes such as those performed by a normal contour shape measuring device or a surface roughness measuring device can be performed. become.
[0024]
Next, as an example of the work 12, a procedure for evaluating the coplanarity (flatness) of an LGA (Land Grid Array) and a BGL (Ball Grid Array) of an LSI package will be described.
FIG. 12 is a plan view and a longitudinal sectional view of the LSI packages 101 and 102 as the work 12. In the case of the LSI package 101 having the LGA shown in FIG. 7A, the height of the land 103 is used. In the case of the LSI package 102 having the BGA shown in FIG. To perform point reciprocal linear scanning to obtain point sequence data. Then, based on the obtained point sequence data, as shown in FIG. 13, the coplanarity of the vertex or the valley bottom is evaluated.
[0025]
FIG. 14 shows a procedure for evaluating LGA coplanarity.
Here, the processing from the trend correction of the data in step S21 to the execution of the Gaussian filter in step S24 is the same as the processing described with reference to FIG. 10, and a description thereof will be omitted. The setting of filter constants and the like necessary for this processing is performed using, for example, a parameter setting viewer as shown in FIG. The presence / absence of trend correction, the high-frequency and low-frequency cutoff frequencies of the filter, and the calculation conditions can be set.
[0026]
FIG. 16 shows two-dimensional point sequence data (b) obtained by performing a filtering process from the two-dimensional point sequence data (a) that has been scanned at a constant pitch and scanned by the LGA. From this point sequence data, the center position of each valley (Land) is extracted by using a valley detection algorithm to obtain point cloud data (FIG. 16C) (S25). As shown in FIG. 17, the mountain valley algorithm gives the minimum depth h and the minimum pitch p from the reference position in advance, and the point sequence data existing in the range of the minimum depth h from the valley portion is only the minimum pitch p. The valley portion is detected by determining whether or not the valley is continued. This method has an advantage that a valley can be detected without having a design value file.
[0027]
As shown in FIG. 18, the number Nx of the lands in the horizontal direction, the number Ny of the lands in the vertical direction, the scan start positions Stx and Sty, the pitch Px in the horizontal direction, and the pitch Py in the vertical direction are prepared in advance as design data. In this case, the point data of the valley may be extracted using the design data.
[0028]
When point cloud data as shown in FIG. 16 (c) is obtained by such processing, it is converted from two-dimensional point cloud data to three-dimensional point cloud data (S26), and finally coplanarity is calculated (S26). S27).
[0029]
Similarly, when evaluating the coplanarity of the BGA, the processing shown in FIG. 19 may be executed. The process from the data trend correction (S31) to the Gaussian filter execution process (S34) is the same as the process from steps S21 to S24 in FIG. 14. After the filtering process, the peaks of each ball are determined using the mountain and valley detection algorithm. What is necessary is just to detect. In this case, a minimum height h and a minimum pitch p are given to detect a peak that satisfies the condition. Subsequent processes (S36, S37) for the extracted point cloud data are the same as steps S26, S27 in FIG.
[0030]
However, in this BGA detection, the vertex (the highest part) of the ball 104 may not be located at the center of the circle as shown in FIG. In addition, as shown in FIG. 3B, the laser probe 35 has an allowable inclination angle of, for example, ± 13 °, and if the scanning position shifts, the reflected light of the laser beam is not detected and correct measurement cannot be performed. There is. In consideration of such a point, it is desirable to perform zigzag scanning on the upper surface of the ball 104 as shown in FIG. 21A or spiral scanning as shown in FIG. Specifically, the XY coordinates of each ball 104 are prepared by, for example, design values or image measurement, and as shown in FIG. 22, the stage is stopped at a point a within the range of the allowable tilt angle (the laser probe 35). , The distance between the patterns ab is measured by the vertex scanning pattern as shown in FIG. Between bc, it moves at high speed without performing measurement. FIG. 23 is a diagram showing a setting screen for setting each parameter and scanning pattern of such a grid array scanning.
[0031]
【The invention's effect】
As described above, according to the present invention, since the non-contact displacement meter follows and measures the displacement of the work along the specified measurement trajectory, even if the work is tilted, its influence on the measurement accuracy is not affected. Small and accurate three-dimensional point sequence data can be obtained. By performing the trend correction on the three-dimensional point sequence data, the subsequent processing is simplified. According to the present invention, since the obtained data is three-dimensional point sequence data, it may be difficult to perform a filtering process or the like. Since the original data is converted to two-dimensional data and subjected to constant pitch processing, predetermined analysis processing such as fine unevenness and contour shape analysis and surface roughness analysis in the Z-axis direction is performed using the filtered two-dimensional data. This has the effect of making it easier to perform.
[Brief description of the drawings]
FIG. 1 is a perspective view of a non-contact three-dimensional image measuring apparatus according to an embodiment of the present invention.
FIG. 2 is a perspective view of the inside of an imaging unit in the apparatus.
FIG. 3 is a diagram showing a configuration of a laser probe in the same device.
FIG. 4 is an overall block diagram of the device.
FIG. 5 is a flowchart showing a procedure of laser measurement by the apparatus.
FIG. 6 is a diagram for explaining a method of calibrating an image and a laser probe in the apparatus.
FIG. 7 is a diagram showing an example of a measurement tool used in the apparatus.
FIG. 8 is a view for explaining an example of scanning measurement of the apparatus.
FIG. 9 is a view for explaining another example of the scanning measurement of the same apparatus.
FIG. 10 is a flowchart of a point sequence data analysis process of the apparatus.
FIG. 11 is a diagram for explaining the analysis processing.
FIG. 12 is a diagram showing an LSI package as an example of a work.
FIG. 13 is a diagram illustrating coplanarity measurement of a BGA of the package.
FIG. 14 is a flowchart showing a procedure of LGA coplanarity evaluation.
FIG. 15 is a diagram showing a parameter setting screen for performing the same evaluation.
FIG. 16 is a diagram showing data obtained at each point in the evaluation processing.
FIG. 17 is a diagram for explaining a mountain-valley algorithm used in the evaluation processing.
FIG. 18 is a diagram illustrating the same evaluation process using design data.
FIG. 19 is a flowchart showing a procedure of BGA coplanarity evaluation.
FIG. 20 is a diagram for explaining a problem of BGA coplanarity evaluation.
FIG. 21 is a diagram illustrating an example of a vertex scanning pattern used in a scanning method for solving the same problem.
FIG. 22 is a diagram for explaining details of the scanning method.
FIG. 23 is a diagram showing a parameter setting screen for realizing the same scanning method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Coordinate measuring machine, 2 ... Computer system, 11 ... Stand, 12 ... Work, 13 ... Measurement table, 14, 15 ... Support arm, 16 ... X-axis guide, 17 ... Imaging unit, 21 ... Computer, 22 ... Keyboard , 23 joystick box, 24 mouse, 25 CRT display, 26 printer, 34, 38 CCD camera, 35 laser probe, 36, 39 lighting device.

Claims (4)

A tertiary measurement unit comprising: an imaging unit that captures a workpiece and outputs two-dimensional image information for image measurement and a non-contact displacement meter that can detect a distance from a predetermined measurement point on the workpiece as a displacement amount. A non-contact three-dimensional measurement method of obtaining three-dimensional point sequence data by moving in the original space,
Confirming the position of the work by measuring the image of the work using the imaging means,
After moving the non-contact displacement meter to a predetermined measurement start point based on this position, acquiring three-dimensional point sequence data by performing scanning measurement along a specified measurement trajectory,
Performing a trend correction on the point sequence data obtained in this step;
Converting the three-dimensional data trend-corrected in this step into two-dimensional data;
Performing a constant pitch process on the two-dimensional data obtained in this step;
Performing a filtering process on the two-dimensional data having a constant pitch in this step. Returning the filtered two-dimensional data to the original pitch,
Returning the two-dimensional data returned to the original pitch in this step to three-dimensional data,
Performing a reverse trend correction on the three-dimensional data obtained in this step. The non-contact three-dimensional measurement method according to claim 1, further comprising a step of performing an arbitrary analysis process on the two-dimensional data subjected to the filter process. An image pickup device that picks up a work made of an IC package and outputs two-dimensional image information for image measurement, and a non-contact displacement meter that can detect a distance from a predetermined measurement point on the work as a displacement amount. A non-contact three-dimensional method for obtaining three-dimensional point sequence data by moving a unit in a measurement three-dimensional space and measuring the flatness of a land grid array or a ball grid array of the IC package based on the three-dimensional point sequence data A measuring method,
Confirming the position of the work by measuring the image of the work using the imaging means,
After moving the non-contact displacement meter to a predetermined measurement start point based on this position, acquiring three-dimensional point sequence data by performing scanning measurement along a specified measurement trajectory,
Performing a trend correction on the point sequence data obtained in this step;
Converting the three-dimensional data trend-corrected in this step into two-dimensional data;
Performing a constant pitch process on the two-dimensional data obtained in this step;
Performing a filtering process on the two-dimensional data converted into a constant pitch in this step;
Extracting data of a plurality of vertices or valleys of the two-dimensional data filtered in this step;
Converting the data extracted in this step from two-dimensional data to three-dimensional data;
Calculating the flatness of the land grid array or ball grid array from the three-dimensional data obtained in this step.

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