JPH079366B2 - Shape measuring method and device - Google Patents

Description

The present invention relates to a shape measuring method for irradiating a surface of an object to be measured mounted on a mounting table with a light beam and measuring the surface shape thereof. Regarding the device.

<Prior Art> In this type of measuring device, an XY movable in the XY directions is used.
Place the object to be measured on the stage, move the stage, and measure the surface shape by moving the irradiation point of the light beam from above to the predetermined measurement point of the object to be measured. ing.

In such a shape measuring apparatus, when continuously measuring the same plurality of objects to be measured, the objects to be measured are arrayed at a plurality of predetermined measurement locations on the XY stage, The irradiation point is moved with respect to the XY stage in accordance with the measurement program including the position data of the measurement location to perform continuous measurement.

A mounting table 1 as shown in FIG. 7 has been conventionally used for mounting a plurality of objects to be measured at respective determined measurement locations.

The mounting table 1 can be fixed at a predetermined position on the XY stage, and three guide pieces 2 for vertically and horizontally arranging and mounting the measured objects W are screwed to the mounting table 1a.

The guide piece 2 is formed so as to abut on two adjacent sides of the quadrangular object to be measured W, and the object to be measured W can be placed at the left and right intervals (Xp) and the upper and lower intervals (Yp).

The semicircular notch 2a provided on the guide piece 2 avoids burrs and dust on the corners of the two pieces of the object to be measured that are in contact with the guide piece 2 and allows the object W to be placed on the guide piece 2 without gaps. It is for abutting.

At the time of measurement, a predetermined number of objects to be measured W are mounted on the mounting table 1 which is fixed on the XY stage in advance, and the XY set on the mounting table 1 as shown in FIG. Origin of plane (0,
The height Za is detected by moving the XY stage so that the irradiation point of the light beam comes to the calculated measurement point coordinate position (Xa, Ya) from (0).

In addition, a large number of small holes 3 provided on the surface of the mounting table 1.
Is an adsorption hole for adsorbing the object to be measured W on the mounting surface 1a.

<Problems to be Solved by the Present Invention> However, when measuring a portion extremely close to the end portion of the measurement surface, the measurement point is calculated due to dimensional accuracy or deformation of the guide piece 2, mounting error with respect to the mounting table 1, or the like. On the other hand, there is a problem in that the position of the actual irradiation point of the light beam is deviated from the guide piece 2 and the mounting surface outside the measurement surface, and the measurement fails.

An object of the present invention is to provide a shape measuring method and apparatus which solve this problem. <Means for Solving the Problems> In order to solve the problems, the shape measuring apparatus of the present invention is: A mounting table having a guide part for mounting an object at a predetermined measurement place, and an object surface mounted on the mounting table is irradiated with a light beam, and the reflected light is received from the mounting surface at the irradiation point. Corresponding to the coordinate data given to the origin of the XY plane set on the mounting surface of the mounting table, the light detecting means for detecting the height of the XYZ moving means for relatively moving the irradiation point to a position to be detected, and detecting the coordinate position of the irradiation point with respect to the origin of the XY plane.
The XY position detecting means, the reference object displayed at a predetermined position, and the coordinate position of the display of the reference object placed at a predetermined measurement place of the mounting table from the XY plane origin are calculated. Then, the calculating means for outputting the calculated coordinate data to the XYZ moving means, and the manual movement for making the display of the reference point and the irradiation point relatively moved by receiving the coordinate data from the calculating means coincide on the screen of the image means Means, and a movement amount detecting means for detecting a relative movement amount of the irradiation point with respect to the mounting table by the manual movement means by calculating the detected coordinates obtained from the XY position detecting means and the light detecting means and the coordinate data from the calculating means. , A storage means for storing the amount of movement as a correction value for the measurement location, and a XYZ movement means for performing correction calculation of the measurement point coordinates of the object to be measured placed at a predetermined measurement location with the correction value stored in the storage means. Compensation calculation output to And means.

Further, in the shape measuring method for measuring the surface shape of the measured object by irradiating the surface of the measured object placed on the mounting table with a light beam and detecting the height of the irradiation point, Place the reference object displayed at a predetermined position at a predetermined measurement position on a mounting table that has a guide for mounting it at a predetermined measurement position, and set it on the mounting surface of the mounting table. Of moving the irradiation point relative to the coordinate position of the reference object display calculated from the origin of the XY plane, and manually moving the irradiation point relative to the mounting table to image the vicinity of the irradiation point. Detecting the coordinate position of the irradiation point with respect to the origin of the XY plane after the manual movement and the step of matching the display of the reference object on the screen, and calculating the detection coordinates and the calculated display coordinates The step of calculating the relative movement amount and the calculated And storing the rotation amount as a correction value, instead of the reference object, the measuring point of the steps of placing the object to be measured in a predetermined measurement position, the measurement object placed in the predetermined measurement position X-Y
The method comprises the steps of correcting the calculated position on the surface with a correction value and measuring the height of the irradiation point in the Z direction by moving the irradiation point relative to the corrected position.

<Operation> Therefore, the measurement point coordinates for the object to be measured are corrected by the correction value stored for each measurement location before the object to be measured, and the irradiation point of the light beam is moved to the corrected coordinate position. The height measurement is performed.

<Embodiment of the present invention> (Figs. 1 to 6) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the overall configuration of a shape measuring apparatus according to an embodiment of the present invention.

In the figure, 10 is a measurement mechanism section, and X- is on the base 11.
A Y stage 12 is provided, and the mounting table 1 similar to the above is fixed on the XY stage 12.

The X stage 12a is configured to move the mounting table 1 in the left-right direction (in FIG. 1), and the Y stage 12b is configured to move the mounting table 1 in a direction orthogonal to the X stage 12a.

An X position detector 12c is provided on the Y stage 12b to detect the amount of movement of the X stage 12a from the reference position (reference origin of the mounting table). A Y position detector 12d for detecting the amount of movement of is provided.

A vacuum device 13 sucks air from the suction holes 3 of the mounting table 1.

Reference numeral 14 denotes an optical sensor unit arranged above the XY stage 12, which receives a light projecting unit 14a that irradiates the mounting table 1 with a light beam and its reflected light, and performs a displacement corresponding to a change in height of an irradiation point. It is composed of a light receiving detector 14b that outputs a signal.

This displacement signal changes according to the distance from the optical sensor unit 14 to the irradiation point, and the distance calculated based on this signal is measured from the optical sensor unit 14 to the origin of the XY plane of the mounting table 1. By subtracting from the height, the height of the irradiation point from the origin is obtained.

A monitor camera 15 that enlarges the vicinity of the irradiation point and outputs an image is integrated with the optical sensor unit 14.

Reference numeral 16 denotes a Z stage that moves the optical sensor unit 14 in a direction orthogonal to the XY stage 12, and the XY stage 12
The movement of both the Z stage 16 and the Z stage 16 is controlled by the XYZ drive unit 17.

Reference numeral 18 denotes a monitor television that displays the video signal from the monitor camera on the screen.

Reference numeral 19 denotes a manual operation unit that moves the XY stage 12 independently by directly inputting a movement signal to the XYZ drive unit 17.

Reference numeral 20 denotes a measurement control unit configured by a computer, which gives a movement signal from the XYZ drive unit 17 to each stage according to an input operation unit 21 for inputting a measurement program, a control signal, etc., and an optical sensor unit. A processing unit 22 that calculates the height in the Z direction of the measurement point of the object to be measured based on the displacement signal from the light reception detection unit 14b of 14 and a display unit 23 that displays data, measurement method, and the like. ing.

As shown in FIG. 2, the processing unit 22 sets X at a predetermined lower left position of the mounting table 1 as a reference origin (0, 0, 0) of absolute coordinates.
-The Y stage 12 and the Z stage 16 are controlled, and the measurement program for the object to be measured is the mounting reference position of the nine measurement locations E1 to E9 determined by the guide piece 2.
Coordinate points of the start point and the end point of the measurement route are set at the measurement point positions with R1 to R9 as the measurement origins.

Therefore, when the same measurement is performed for all DUTs, continuous measurement is performed by activating the measurement program for one DUT from the mounting reference positions R1 to R9 of the measurement locations E1 to E9. be able to.

FIG. 3 is a flow chart showing a procedure of a correction process performed in advance before the measurement of the object to be measured.

First, at the measurement points E1 to E9 of the mounting table 1, as shown in FIG. 4, the same shape as the object to be measured, from the reference mounting position (lower left corner) to the coordinate points (X ₀ , Y ₀ , Z ₀ ) When the reference object 30 having the display point M marked at the position is fixed and placed and the correction process is started, the count values Cn and Cm (values for the array position matrix) are set to 1 in step 1, respectively. Initialization is performed (n and m are the number of arrays at the measurement location, and both are 3).

In step 2, the count value Cn, with respect to Cm, Xs = X1 + Xp ( Cn-1) + X 0 Ys = Y1 + Yp (m-Cm) + Y 0 Zs = mounting reference position R1 of the measured locations E1 by a calculation of Z ₀ is It is calculated.

In step 3, a movement signal corresponding to this coordinate value (Xs, Ys, Zs) is output to the XYZ drive unit 17, and the XY stage 12
The Z stage 16 is moved, and the light beam from the optical sensor unit 14 irradiates the coordinate position (Xs, Ys, Zs) of the mounting table 1.

After the irradiation point is focused in step 4, a manual movement permission signal is output to the display unit 23 in step 5.

Here, on the screen of the monitor TV 18, the irradiation point of the light beam and the display point M of the reference object 30 are imaged in a state where they do not match due to an attachment error of the guide piece 2 or the like, and step 6 Then, the XY stage 12 is manually moved by the operation of the manual operation unit 19 to match the irradiation point and the display point on the screen of the monitor TV 18.

After the irradiation point and the display point match by this manual operation,
In step 7, the key operation for fixing the position is detected.

In step 8, the coordinate position (Xr, Yr, Zr) of the irradiation point (display point) after the manual movement is detected.

This detection is a detection signal from the XY position detectors 12c and 12d,
The displacement signal from the optical sensor unit 14 corresponds to the distance between the optical sensor unit 14 and the irradiation point. In the processing unit 22, from the reference origin of the mounting table 1 to the optical sensor unit 14. By subtracting the distance corresponding to the displacement signal from the distance (which changes with the movement of the Z stage),
Zr will be detected.

This calculation is always performed by the processing unit 22 even during measurement.

In step 8, the calculated coordinate position of the display point (Xs, Ys,
Zs) and the coordinate position (Xr, Yr, Zr) after manual movement, the movement amount ΔX = Xr−Xs ΔY = Yr−Ys ΔZ = Zr−Zs is calculated, and this movement amount is measured in step 10. The correction value ΔR1 of the location E1 is stored in the memory at the addresses (Cm, Cn), that is, the addresses (1, 1).

In step 11, Cn is increased by 1 and this value is n + 1.
Whether it is equal to or less than (= 4) is determined in step 12,
If it is smaller, return to step 2.

When Cn is equal to “4”, Cn is set to 1 in step 13, Cm is increased by 1, and then the value of Cm is m + 1 (=
Whether it is equal to or smaller than 4) is determined in step 14, and when it is smaller, the process returns to step 2.

Therefore, the correction values ΔR1 to ΔR7 of the mounting reference positions R1 to R7 at the respective measurement locations E1 to E7 are ΔR1 to ΔR3, as shown in FIG.
ΔR6 to ΔR4 and ΔR7 to ΔR9 are arranged and stored in the memory address corresponding to the measurement location in this order.

FIG. 6 is a flowchart showing a processing procedure in which an object to be measured is placed at each measurement place instead of the reference object 30 and the same measurement is continuously performed. It is assumed that a common series of measurement programs is stored in advance at a predetermined address.

In step 1 in FIG. 6, the value W of the work counter
Is initialized to 1, and in step 2, the matrix value (Cm, Cn) of the measurement location (E1 when W = 1) corresponding to this W value, that is, (1, 1) is calculated.

In step 3, the correction value ΔR (W) (ΔX, ΔY, Δ) at the measurement location is calculated from the address corresponding to the matrix values (Cm, Cn).
X) is read out and the corrected coordinates of the mounting reference position are calculated by the following equation.

Xr = X1 + Xp (Cn-1) + ΔX Yr = Y1 + Yp (M-Cm) + ΔY Zr = ΔZ In step 4, the measurement program is read from a predetermined address, and in step 5, the read coordinate data of the measurement program is read. Corrected coordinates of mounting reference position (Xr,
Yr, Zr) are added.

As a result, the coordinate data of the measurement program is stored on the mounting table 1.
Will be converted into absolute coordinates with respect to the reference origin.

In step 6, the measurement program is executed based on the converted coordinate data, and the movement signal corresponding to this coordinate data is output to the XYZ drive unit 17.

In step 7, the measurement data (height data) obtained during the measurement is sequentially read and stored sequentially from a predetermined address.

In step 8, a determination calculation such as parallelism and warpage of the measurement surface is performed based on the stored measurement data, and in step 9, the determination result is stored in a predetermined address.

In step 10, the value of W is incremented by 1, and in step 11,
It is judged whether or not the value of W is equal to m × n + 1 (= 10), and if not equal (small), the process returns to step 2.

This process is repeated for all DUTs and W is m
When it becomes equal to × n + 1 (= 10), the determination results of all the DUTs are displayed on the display unit 23 in step 12.

<Other Embodiments of the Present Invention> In the above embodiment, the mounting table 1 was moved in the XY direction on the XY stage 12, and the optical sensor unit 14 was moved in the Z direction. The invention is not limited to the embodiment described above, and the optical sensor unit may be controlled to move in the XYZ directions with respect to the fixed mounting table.

Further, in the above-mentioned embodiment, the mounting table 1 having 3 × 3 measuring locations has been described. However, for example, by measuring the mounting table having 10 × 10 measuring locations, a small object to be measured can be measured. Can be performed continuously.

Further, in the case where various types of mounting tables are prepared in advance as described above, the correction value data for each mounting table is stored in advance, so that the measurement can be quickly performed.

<Effects of the Present Invention> As described above, the shape measuring method and apparatus of the present invention can correct the manufacturing error of the mounting table and the guide portion to measure the object to be measured, and therefore the positioning of the measuring point is accurate. In addition, it is possible to measure the portion near the edge of the measurement surface without failure.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of an embodiment of the present invention, FIG. 2 is a plan view of a main part of the embodiment, FIG. 3 is a flowchart showing a processing procedure of the embodiment, and FIG. FIG. 3 is a perspective view showing a main part of one embodiment. FIG. 5 is a memory section showing the processing result of FIG. 3, and FIG. 6 is a flow chart showing the processing procedure of one embodiment. FIG. 7 is a perspective view of a main part used in the conventional apparatus and the apparatus of one embodiment, and FIG. 8 is a plan view in which XY coordinates are set in FIG. 10 …… Measurement mechanism section, 11 …… Base, 12 …… XY stage, 14 …… Optical sensor section, 15 …… Monta camera, 16 …… Z
Stage, 17 …… XYZ drive, 18 …… Monitor TV, 20
…… Measurement control unit, 21 …… Input operation unit, 22 …… Processing unit, 23
…… Display section.

Claims (2)

[Claims] 1. A mounting table having a guide portion for mounting an object to be measured at a predetermined measurement place, and an object surface mounted on the mounting table is irradiated with a light beam,
The light detection means for receiving the reflected light to detect the height of the irradiation point from the mounting surface, the image means for displaying an image near the irradiation point on the screen, and the setting surface for the mounting table of the mounting table XYZ moving means for relatively moving the irradiation point to a position corresponding to coordinate data given with respect to the origin of the XY plane, and an XY position for detecting a coordinate position of the irradiation point with respect to the origin of the XY plane. The coordinate position from the XY plane origin of the detection means, the reference object displayed at a predetermined position, and the display of the reference object placed at the predetermined measurement place of the mounting table is calculated. hand,
Calculating means for outputting the calculated coordinate data to the XYZ moving means; and a manual moving means for matching the irradiation point and the display, which are moved relative to each other by receiving the coordinate data from the calculating means, on the screen of the image means. A movement for detecting a relative movement amount of the irradiation point with respect to the mounting table by the manual movement means by calculation of detection coordinates obtained from the XY position detection means and the light detection means and coordinate data from the calculation means. Amount detection means, storage means for storing the movement amount as a correction value for the measurement location, and measurement point coordinates of the object to be measured placed at the predetermined measurement location with the correction values stored in the storage means. Correction calculation
A shape measuring device comprising a correction calculation means for outputting to an XYZ moving means. 2. A shape measuring method for measuring the surface shape of an object to be measured by irradiating the surface of the object to be measured placed on a mounting table with a light beam and detecting the height of the irradiation point. , A step of placing a reference object, which is displayed at a predetermined position, on a predetermined measuring position of a mounting table having a guide portion for placing an object on the predetermined measuring position; A step of relatively moving the irradiation point to a coordinate position of the display of the reference object calculated from the origin of the XY plane set on the mounting surface, and manually moving the irradiation point with respect to the mounting table, The step of matching the display on the screen near the irradiation point and the coordinate position of the irradiation point with respect to the origin of the XY plane after the manual movement, and the detected coordinates and the coordinates of the calculated display. The relative movement amount of the irradiation point is calculated by A step of storing the calculated movement amount as a correction value, a step of placing the measured object in place of the reference object at the predetermined measurement place, and a step of placing it at a predetermined measurement place. XY of the measured point of the measured object
Correcting the calculated position on the surface with the correction value, and moving the irradiation point to the corrected position relative to the irradiation point Z.
A shape measuring method comprising a step of measuring a height in a direction.