JP2019060812A - Step measurement device, step measurement method, step measurement program, and equipment - Google Patents

Abstract

To provide a step measurement device, a step measurement method, a step measurement program, and equipment capable of accurately measuring a step height without increasing a load of arithmetic processing.SOLUTION: A step measurement device for measuring a height of a step positioned on a surface of an object to be measured comprises: a light projection part 11; a light reception part 12; a measurement control part; and an arithmetic part. The measurement control part acquires shape data including at least a reference point positioned on a plane part as a reference of step measurement, a measurement point as a measurement position of a step height from the reference point and three reference points positioned on the plane part on the surface of the object W to be measured. The arithmetic part specifies a plane of the plane part by a plane equation including the three reference points, and calculates a deviation amount in a height direction between the plane position of the measurement point on the specified plane and the reference point in the shape data, and calculates a value calculated by correcting a difference in height between the reference point and the measurement point in the shape data by the deviation amount as the step height.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a step measurement apparatus, a step measurement method, a step measurement program, and a device.

  Conventionally, an optical displacement meter is known that measures various dimensions of a measurement object by irradiating the surface of the measurement object with light and measuring the reflected light (see, for example, Patent Document 1).

JP, 2013-170838, A

  The displacement gauge described in Patent Document 1 uses a profile (master profile) as a whole reference in order to correct the displacement of the measurement object. In this case, it is necessary to calculate the difference between the profile measured and the master profile for each measurement, which is unsuitable for in-line measurement in which a large number of measurement objects are measured one after another.

  An object of one embodiment of the present invention is to provide a step measurement apparatus, a step measurement method, a step measurement program, and an apparatus capable of accurately measuring the step height without increasing the load of arithmetic processing.

  According to a first aspect of the present invention, there is provided a step measuring device for measuring the height of a step located on the surface of a measurement object, the projection unit irradiating measurement light to the measurement object, and the measurement A light receiving unit receiving light reflected from the object; a measurement control unit performing measurement by the light emitting unit and the light receiving unit; and acquiring shape data indicating a surface shape of the measurement object; And a calculation unit that calculates the height of the step on the basis of the measured shape data, and the measurement control unit is positioned on a flat portion which is a reference of the step measurement among the surfaces of the measurement object. The shape data including at least a reference point, a measurement point which is a measurement position of a step height from the reference point, and three reference points located on the flat portion is acquired, and the operation unit The plane equation according to a plane equation including the three reference points Define the plane of the plane, calculate the amount of deviation in the height direction between the plane position of the measurement point in the plane and the reference point in the shape data, and calculate the reference point and the measurement point in the shape data A level difference measuring apparatus is provided, which calculates, as a level difference height, a value obtained by correcting the difference in height with the amount of deviation.

  According to a second aspect of the present invention, there is provided a step measurement method for measuring the height of a step located on the surface of a measurement object, wherein the step of irradiating the measurement object with measurement light from a light projection unit; The step of receiving the reflected light from the object to be measured by the light receiving portion, and the position on the flat portion serving as the reference of the step measurement among the surfaces of the object to be measured based on the measurement data output from the light receiving portion Acquiring shape data of the measurement object including at least a reference point to be measured, a measurement point which is a measurement position of the step height from the reference point, and three reference points located on the flat portion And the plane equation including the three reference points to define the plane of the plane portion, and the amount of deviation in the height direction between the plane position of the measurement point on the plane defined and the reference point in the shape data Calculation of the shape data A value obtained by correcting the difference in height between the measuring point and the reference point by the shift amount, and a step of calculating a step height, the level difference measuring method is provided.

  According to a third aspect of the present invention, there is provided a step measurement program for measuring the height of a step located on the surface of a measurement object, the function of irradiating the measurement object with measurement light from the light projection unit, Based on the function of receiving the reflected light from the measurement object by the light receiving unit and the measurement data output from the light receiving unit, the surface of the measurement object is positioned on a flat surface serving as a reference for measuring the step. A function of acquiring shape data including at least a reference point to be measured, a measurement point which is a measurement value of the step height from the reference point, and three or more reference points located on the flat portion; The plane of the plane portion is defined by a plane equation including reference points of places, and the amount of deviation in the height direction between the plane position of the measurement point in the plane and the reference point in the shape data is calculated. The group in the shape data A value obtained by correcting the difference in height between the point and the measurement point by the shift amount, thereby realizing a function of calculating a step height, to the computer, step measurement program is provided.

  According to an aspect of the present invention, there is provided a step measurement apparatus, a step measurement method, a step measurement program, and an apparatus capable of accurately measuring the step height without increasing the load of arithmetic processing.

FIG. 1 is a perspective view showing a step measurement apparatus according to an embodiment. FIG. 2 is a functional block diagram of the step measurement apparatus according to the embodiment. FIG. 3 is a flowchart of the step measurement method of the embodiment. FIG. 4 is an explanatory view of a shape measuring process using a laser measuring device. FIG. 5 is a plan view and a partial cross-sectional view showing an example of the measurement object. FIG. 6 is a view showing a three-dimensional measurement image obtained by the step measurement device. FIG. 7 is a schematic view showing a state in which the measurement object W is inclined on the pallet P. As shown in FIG.

Hereinafter, embodiments of the present invention will be described using the drawings.
In the drawings, an XYZ coordinate system is shown as a three-dimensional orthogonal coordinate system as appropriate. In the XYZ coordinate system, the Z-axis direction is the vertical direction. The X-axis direction is a direction orthogonal to the Z-axis direction, which is the left-right direction in FIG. The Y-axis direction is orthogonal to both the X-axis direction and the Z-axis direction.

FIG. 1 is a perspective view showing a level difference measuring apparatus according to the present embodiment. FIG. 2 is a functional block diagram of the level difference measuring apparatus of the present embodiment.
As shown in FIG. 1, the step measuring apparatus 100 according to the present embodiment supports the laser measuring instrument 10, the laser measuring instrument 10 and the measurement object W, and moves the laser measuring instrument 10 relative to the measurement object W. A stage device 20 and a display unit 30 with a touch panel are provided. The laser measurement device 10 has a light projecting unit 11 that irradiates the measurement object W with the measurement light, and a light receiving unit 12 that receives the reflected light from the measurement object W. In the case of the present embodiment, the light projecting unit 11 irradiates the measurement object W with a line-shaped laser beam for acquiring shape data by a light cutting method.

  The stage device 20 has a work stage unit 21 and a head stage unit 22. The work stage unit 21 is located below the stage device 20 and supports a pallet P that holds a plurality of measurement objects W. The work stage unit 21 moves the pallet P in the horizontal direction. The head stage unit 22 is located above the stage unit 20 and supports the laser measuring instrument 10. The head stage unit 22 moves the laser measuring instrument 10 in the horizontal direction and the vertical direction. According to the above configuration, the level difference measuring apparatus 100 can sequentially measure the level differences of the plurality of measurement objects W on the pallet P, and can be suitably used for in-line inspection.

  As shown in FIG. 2, the level difference measuring apparatus 100 includes an apparatus control unit 50. The device control unit 50 is connected to the laser measuring device 10, the stage device 20, and the display unit 30, and controls them comprehensively. In the case of this embodiment, the device control unit 50 can communicate with the external server 200. The device control unit 50 is a computer including hardware such as a main control unit, a storage unit, a work storage unit, and a communication unit.

  The apparatus control unit 50 displays an image on a display unit 30 with a touch panel, a measurement control unit 51 that controls the laser measuring unit 10 and the stage unit 20, an operation unit 52 that processes shape data acquired by the laser measuring unit 10, And an operation input unit 54 for receiving an operation input from the touch panel of the display unit 30 with a touch panel.

  The measurement control unit 51 is communicably connected to the communication unit 13 of the laser measuring instrument 10. The measurement control unit 51 outputs a control signal for operating the light emitting unit 11 and the light receiving unit 12 to the communication unit 13. The measurement control unit 51 acquires measurement data acquired by the light receiving unit 12 via the communication unit 13. The measurement control unit 51 outputs, to the stage device 20, a control signal based on position control information of the measurement object W and the laser measurement device 10.

The calculation unit 52 calculates the height of the step of the measurement object W based on the shape data measured by the measurement control unit.
The display unit 30 with a touch panel displays an image based on shape data obtained by measuring the measurement object W, and the result of the step measurement process using the image data. The operation state of the device control unit 50 is displayed on the display unit 30 with a touch panel, and the user can operate the touch panel of the display unit 30 with a touch panel to perform operation input such as menu selection operation and display image operation. It is. The level | step difference measuring apparatus 100 may be equipped with a touch panel and a display panel as a separate apparatus.

  FIG. 3 is a flowchart of the step measurement method of the present embodiment. FIG. 4 is an explanatory view of a shape measuring process using a laser measuring device. FIG. 5 is a plan view and a partial cross-sectional view showing an example of the measurement object. FIG. 6 is a view showing a three-dimensional measurement image obtained by the step measurement device.

The level | step difference measurement method using the level | step difference measurement apparatus 100 contains process S1-S4 shown in FIG.
Step S1 is a step of measuring the shape of the measurement object W.
In step S <b> 1, as shown in FIG. 4, the level difference measuring apparatus 100 measures the surface shape of the measurement object W with the laser measuring device 10.

  Specifically, the device control unit 50 outputs a control signal from the measurement control unit 51 to the communication unit 13 and applies the measuring light L to the object to be measured W from the light projecting unit 11 of the laser measuring instrument 10, and measurement. And a step of receiving the reflected light from the object W by the light receiving unit 12. At this time, the measurement control unit 51 outputs a control signal to the stage device 20 and causes the work stage unit 21 to move the measurement object W in the −X direction. As a result, the measurement light L emitted from the light projection unit 11 is scanned in the X direction on the surface of the measurement object W, and the light receiving unit 12 samples the reflected light at constant intervals. Generate measurement data. The communication unit 13 transmits the measurement data obtained by the light receiving unit 12 to the measurement control unit 51.

  The measurement object W in the step measuring device 100 is an electronic component of several mm to several cm in length, such as a small actuator. For example, as shown in FIG. 5, the measurement object W has a rectangular parallelepiped casing 71 and a main body 72 accommodated in the casing 71. The object to be measured W has a flat portion 71s on the top surface of the housing 71, which serves as a reference for measuring the level difference. The measuring object W has two concave portions T1 and T2 aligned in the longitudinal direction of the housing 71 at the central portion of the flat portion 71s.

The concave portion T1 and the concave portion T2 have through holes 73 vertically penetrating through the housing 71, as shown in the partial cross-sectional view on the right side of FIG. The upper surface of the main body 72 is exposed to the inside of the through hole 73. In the present embodiment, the concave portions T1 and T2 are concave portions in which the through hole 73 is a part of the side surface and the upper surface of the main body portion 72 exposed to the inside of the through hole 73 is the bottom surface.
The level difference measuring apparatus 100 sets the distance in the vertical direction from the reference point P0 set at the center of the flat portion 71s of the housing 71 to the measurement point Tp on the bottom surface of the concave portions T1 and T2 as the stepped height of the concave portions T1 and T2. taking measurement.

  In step S1, the measurement control unit 51 is a measurement target including the reference point P0 shown in FIG. 5, concave portions T1 and T2 including the measurement point Tp, and three reference points P1, P2 and P3 included in the flat portion 71s. The surface area of the object W is measured by the laser measuring device 10. The laser measuring instrument 10 transmits measurement data including position information of the reference point P0, the measurement point Tp, and the reference points P1 to P3 to the measurement control unit 51. The device control unit 50 stores the measurement data acquired by the measurement control unit 51 in the storage unit of the device control unit 50 as shape data of the measurement object W. In the case of the present embodiment, by measuring the measurement object W shown in FIG. 5, shape data capable of constructing a three-dimensional measurement image shown in FIG. 6 can be obtained.

  In step S2 illustrated in FIG. 3, the flat surface portion 71s is identified based on the shape data acquired via the measurement control unit 51. Arithmetic unit 52 acquires shape data of measurement object W from the storage unit, and a plane equation using position information of three reference points P1, P2, and P3 included in the shape data on measurement object W. The flat portion 71s is identified.

  In the present embodiment, as shown in FIG. 5, three reference points P1 to P3 are set at positions surrounding the measurement point Tp (concave portions T1 and T2) in plan view. Thereby, even in the flat portion 71s, the flat surface in the concave portions T1 and T2 and the region in the vicinity thereof can be specified based on the three reference points P1 to P3. Therefore, the step height correction based on the inclination of the flat portion 71s Can be done more accurately.

In step S3, the amount of deviation in the height direction between the flat portion 71s specified by the calculation unit 52 in step S2 and the reference point P0 in the shape data is calculated.
Here, FIG. 7 is a schematic view showing a state in which the measuring object W is inclined on the pallet P. As shown in FIG. When the measurement object W is inclined with respect to the horizontal direction, the depth (step height) of the recess T1 directly obtained from the shape data is the difference in height position between the reference point P0 and the measurement point Tp. Therefore, as shown in FIG. 7, when the object to be measured W is inclined in a direction inclined upward from the reference point P0 toward the recess T1, the depth of the recess T1 obtained as the difference in height position in shape data h is larger than the actual depth of the recess T1.

  The difference in the depth value of the recess T1 is caused by the flat surface 71s and the horizontal plane H0 passing through the reference point P0 being shifted due to the inclination of the measurement object W. In step S3, a shift amount Δh is calculated to correct the reference point in the height direction of the measurement point Tp from the reference position Tp0 in the horizontal plane H0 to the reference position Tp1 in the plane of the flat portion 71s.

  The computing unit 52 acquires the height position (Z coordinate) of the reference position Tp1 at the plane position (XY coordinate) of the measurement point Tp in the plane portion 71s specified in the process S2. The computing unit calculates the difference between the height position of the reference position Tp1 and the height position of the reference point P0 as the deviation amount Δh of the reference point P0 in the height direction.

  In step S4, the depth of the recess T1 is corrected by the amount of deviation Δh obtained in step S3. Specifically, the calculation unit 52 corrects the depth of the recess T1 calculated from the shape data (difference between the measurement point Tp and the height position of the reference point P0) by the deviation amount Δh. In the case of this embodiment, since the depth h of the recess T1 obtained from the shape data is a value larger than the actual depth, the shift amount Δh is subtracted from the depth h of the recess T1. Thereby, the actual depth (h-Δh) of the recess T1 is obtained.

  In the present embodiment, three reference points P1 to P3 are set in addition to the reference point P0, but any one of the three reference points P1 to P3 is used as a reference of the step height. It may be a point. In this case, since the plane including the reference point can be specified by the plane equation, it is possible to more accurately correct the depths of the recesses T1 and T2 based on the deviation amount Δh of the reference point. Therefore, the step height corresponding to the depth of the concave portions T1 and T2 can be measured with high accuracy.

  According to the step measurement apparatus 100 of the present embodiment described above, the plane equation is used even when the measurement object W is inclined in the depth measurement of the concave portions T1 and T2, ie, the measurement of the step height. Since the shift amount Δh in the height direction between the measurement point Tp and the reference point P0 due to the inclination of the measurement object W is acquired based on the specified plane, and the depths of the recesses T1 and T2 are corrected, the measurement object Deviation of the measurement value due to the inclination of the object W can be reduced, and high-precision step height measurement is possible. In the present embodiment, it is only necessary to have shape data including position information of at least four points for step measurement and inclination correction, so the calculation load is low and it is suitable for in-line measurement.

A program for realizing the function of the step measurement apparatus 100 according to the present embodiment is recorded in a computer readable recording medium, and the program recorded in the recording medium is read by the computer system and executed. May be The "computer system" mentioned here includes an OS and hardware such as peripheral devices.
The "computer system" also includes a WWW system provided with a homepage providing environment (or display environment). The term "computer-readable recording medium" refers to a storage medium such as a flexible disk, a magneto-optical disk, a ROM, a portable medium such as a ROM or a CD-ROM, or a hard disk built in a computer system. Furthermore, the "computer-readable recording medium" is a volatile memory (RAM) in a computer system serving as a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, the aspect which holds a program for a fixed time is included.

  The program may be transmitted from a computer system in which the program is stored in a storage device or the like to another computer system via a transmission medium or by transmission waves in the transmission medium. Here, the “transmission medium” for transmitting the program is a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. Further, the program may be configured to realize part of the functions described above. Furthermore, it may be a configuration that can realize the functions described above in combination with a program already recorded in the computer system, a so-called difference file (difference program).

  11 light emitting unit 12 light receiving unit 20 stage device 51 measurement control unit 52 arithmetic unit 71s flat portion 100 step measuring device h depth L measuring light P Pallet, P0 ... reference point, P1 ... reference point, S1, S2, S3, S4 ... process, T1, T2 ... recess, Tp ... measurement point, W ... measurement object

Claims (9)

A step measuring device for measuring the height of a step located on the surface of a measurement object, comprising:
A light projecting unit that irradiates measurement light to the measurement object;
A light receiving unit that receives light reflected from the object to be measured;
A measurement control unit that performs measurement by the light emitting unit and the light receiving unit and acquires shape data indicating a surface shape of the measurement object;
An operation unit that calculates the height of the step based on the shape data measured by the measurement control unit;
Equipped with
The measurement control unit is configured to measure, on the surface of the measurement object, a reference point located on a flat portion serving as a reference for measuring the level difference, a measurement point which is a measurement position of the height of the level difference from the reference point, and the plane Obtaining the shape data including at least three reference points located on the part;
The arithmetic unit is
Define a plane of the flat portion by a plane equation including the three reference points,
Calculating a shift amount in a height direction between a planar position of the measurement point on the defined plane and the reference point in the shape data;
A value obtained by correcting the difference in height between the reference point and the measurement point in the shape data using the amount of deviation is calculated as a step height.
Step measurement device.   The level | step difference measurement apparatus of Claim 1 which makes any one of the said three reference points the said reference point.   The level difference measuring apparatus according to claim 1, wherein the three reference points are set at positions surrounding the measurement point in plan view.   The level | step difference measuring apparatus of any one of Claim 1 to 3 whose level | step difference of the said measurement object is the depth of the recessed part adjacent to the said plane part of the said measurement object and dented below.   The level | step-difference measuring device of any one of Claim 1 to 4 which has a stage apparatus which makes the said measurement object relatively move with respect to the said light projection part and the said light reception part. The stage device can support a pallet that holds a plurality of the measurement objects.
The steps on the surface of the measurement object on the pallet can be sequentially measured.
The level | step difference measuring apparatus of Claim 5. A step measuring method for measuring the height of a step located on the surface of a measurement object, comprising:
Irradiating the measurement object with measurement light from a light emitter;
Receiving light reflected from the object to be measured by a light receiving unit;
At the measurement position of the step height from the reference point and the reference point located on the flat portion which becomes the reference of the step measurement among the surfaces of the measurement object based on the measurement data output from the light receiving unit Acquiring shape data of the measurement object including at least a measurement point and three reference points located on the flat portion;
The plane of the plane portion is defined by a plane equation including the three reference points, and the amount of deviation in the height direction between the plane position of the measurement point in the plane and the reference point in the shape data is calculated. Calculating as a step height a value obtained by correcting the difference in height between the reference point and the measurement point in the shape data using the amount of deviation;
Step measurement method. A step measurement program for measuring the height of a step located on the surface of a measurement object, comprising:
A function of irradiating the measuring object with measuring light from a light emitting unit;
A function of receiving reflected light from the object to be measured by a light receiving unit;
Based on the measurement data output from the light receiving unit, among the surface of the measurement object, a reference point located on a flat portion serving as a reference for measuring a step, and a measurement value of the step height from the reference point A function of acquiring shape data including at least a measurement point and three or more reference points located on the flat portion;
The plane of the plane portion is defined by a plane equation including the three reference points, and the amount of deviation in the height direction between the plane position of the measurement point in the plane and the reference point in the shape data is calculated. A function of calculating, as a step height, a value obtained by correcting the difference in height between the reference point and the measurement point in the shape data using the amount of deviation;
A step measurement program that realizes a computer.   A computer-readable recording medium or an apparatus on which the program according to claim 8 is stored.