JPS5847209A - Device for measuring surface configuration - Google Patents

Abstract

PURPOSE:To provide a non-contact precise measurement of the surface configuration of an object to be measured by means wherein a light beam radiates an object surface and its reflective light is passed to a photo sensor to provide variation of a distance in the Z direction, said variation amount being into computor together with the amount of movement of the object under measurement in the X and Y direction. CONSTITUTION:The object under measurement is placed on a pass and is moved on transport tables in the X and Y directions of the X-Y plane. When a light beam from the light source 61 of the photo sensor 6 radiates the object surface, the signals i1, i2 output from the light receiving element 64 are input into the computor 65 so that displacement Z1 in the direction of the object surface is obtained. This output Z1 and the displacement X, Y obtained from the movement detectors 10, 11 are input to the signal processor 12, where the surface configuration of the object can be computed and output.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface profile measuring device capable of measuring the surface profile of a workpiece over a wide area at high speed and with high precision using an optical sensor.

Conventionally, as a method of measuring the surface shape (surface irregularities) of the object to be measured, a method is used in which the tip of (1) is brought into contact with the surface of the object to be measured and the button or the object to be measured is moved. . However, in this method, (a) since it is a contact method, it is not possible to increase the speed at which the surface is scanned, and the measurement takes time.

(b) There is a risk of damaging the object to be measured.

(c) Scanning is difficult if there are steps on the surface of the object to be measured.

There were drawbacks such as.

Another method is also used, in which a silicon wafer or flat glass is placed on the surface of the object to be measured and measurements are made using interference fringes that occur when the surface of the object is distorted. However, in this case, it is difficult for one person to measure (a) the surface of the object to be measured is rough;
The surface must be polished to a mirror surface before measurement.

(b) Displacements from about the wavelength to several tens of times that wavelength can be measured, but the spacing between the stripes becomes narrower than that, making it impractical.

(c) It is difficult to measure over a wide area.

There were drawbacks such as.

The present invention corrects the above-mentioned drawbacks and provides a surface shape measuring device that can measure a wide area non-contactly, at high speed, with high precision, even on rough surfaces or with steps. The purpose is to

An embodiment of the present invention will be described below based on the drawings.

FIG. 1 shows a surface profile measuring device according to an embodiment of the present invention.

In the same figure, reference numeral 1 denotes a flat base on which a fixed object W is placed, and this base 1 moves pulses in the horizontal direction (along the This X-direction moving table 2 is movable by a motor 3.
is movable in the Y-direction perpendicular to the X-direction by a pulse motor 5 in the vertical direction and the Y-axis direction on the table 4. Since the Y-direction moving table 4 is installed vertically, the object W to be measured is placed vertically on the surface of the base 1.

In front of the base 1, an optical sensor 6 is fixedly installed on a fixed base 7.

The optical sensor 6, shown in FIG. 2, includes a light source 61 that emits a beam of light with good directionality, a front lens 62 that focuses this light beam and irradiates it onto the surface of the object W to be measured, and an optical axis. is shifted at a certain angle from the optical axis of the irradiation lens 62, and focuses the reflected light beam from the light spot on the surface of the object W to be measured to form an image of the reflected light spot on the light receiving portion 64a of the light receiving element 64. Image lens 63
The light receiving section 64.8 is arranged so as to match the trajectory when the reflected light spot changes depending on the displacement of the surface of the object W in seven directions (directions perpendicular to the X-Y plane). 6/
A light-receiving element 64 outputs two signals 11 and i according to the position of the image of the reflected light spot on Ia, and two outputs of the light-receiving element 64 i, i, nt, etc. on the surface of the object W to be measured 4
- The arithmetic unit 65 that performs the height change 71 is composed of one J.

As shown in FIG. 3, the surface of the object W to be measured is
If there is a displacement (in a direction perpendicular to the Y plane) (that is, unevenness on the surface), the light beam from the black lens 62 will be reflected on the surface, and the image Q of the reflected light point formed by the imaging lens 63 will be in the Z direction. It is displaced in the Z direction corresponding to the displacement of . In order to detect the displacement of the image Q of the reflected light spot σ in these seven directions, the light receiving part 64a of the light receiving element 64 is moved in the Z direction to the axis trace of the image Q of the reflected light spot, as described above. It is a coincidence.

For example, the light receiving element 64 is shown in FIG. J-J:
In other words, a one-dimensional diffused PIN diode is used that converts displacement in the Z direction into an electrical signal. This light-receiving element 64 has a light-receiving current flowing through resistors R and R connected to terminals 64b and 164C provided at both ends in seven directions.
, 12 changes according to the change in the position of the image Q of the reflected light spot in the 7 directions, and the distance Z in the 7 directions of the light spot Fj + Q from the center line 1°, Ham 1 - Jin, Z, − is obtained as ■(1, t, (L K I Lj constant vi).

X on the X-direction moving table 2 and the Y-direction moving table 4
Each movement in the direction and Y direction ff1X, Y is determined by an X direction movement amount detector 10 which receives the drive outputs of an X driver 8 and a Y driver 9 which respectively drive a pulse motor 3.5, and an XY direction movement aim detector 11 J: detected.

Processor No. 48 12 connects the output cuff 1 of the arithmetic unit 65 of the optical sensor 16 to the X-direction movement amount detector 10,
A function of receiving the outputs X and Y of the Y-direction movement detector 11 and outputting the surface shape of the object to be measured W, a function of outputting a control signal for controlling the X driver 8 and Y driver 9, and a function of outputting a control signal for controlling the X driver 8 and the Y driver 9. The heights of the three points on the surface of Z
It has a function to output the position of contour lines in 7 directions based on the height of the direction.

Since the surface shape measuring device is configured as described above, the object to be measured W is installed on the base 1, and the X-direction moving table 2
While moving the base 1 in the X-Y plane using the Y-direction moving table 4, a light beam from a light source 61 of a photosensor (J-6) is irradiated onto the surface of the object W to be measured.
1, iU is output, and the arithmetic unit 65 outputs signals ii, il
Outputs Z1, X, and Y of the optical sensor 6 of the object to be measured W upon receiving the
The amount of movement X, Y in the near 'j direction from the direction movement amount detector 10.11 is output to the signal processor 12.

The signal processor 12 calculates the amount of displacement 71 appearing on the optical sensor 6 and X, Y.
The directional movement amounts X and Y are taken in, and the surface shape of the object W to be measured is calculated and output.

FIG. 5 shows a case where the optical sensor 6 is installed on a seven-direction moving table 13 so as to be movable in the Z-axis direction perpendicular to the X-Y plane by a motor 14. The 7-direction movement 12 of the optical sensor 6 on this Z-direction movement table 13 is caused by the frequency not being stabilized. Z-direction moving system detector 1 consisting of an interferometric length measuring device that detects the movement of optical sensors 1 and 6 using a laser
5.

FIG. 6 shows a structure for a surface-shaped oil cylinder in which the optical sensor 6 can be moved in seven directions as shown in FIG.

That is, the signal processor 12 is the arithmetic unit 65 of the optical sensor 6.
The height of the surface of the object W in the seven directions is calculated by adding the output Z1 of the detector 15 and the output Z of the seven-direction movement detector 15.
, the X-direction movement amount detector 10 and the Y-direction movement i! IIm
In addition to the function of receiving the output X1Y of the detector 11 and calculating and outputting the surface shape of the object W to be measured, the X driver 8 and the Y driver 9 also drive 1:-914! A function of outputting a control signal to control the Z driver 16 for IJ, an X direction movement table 2,
In order to know the Z-direction deviation amount (meandering) 72 that occurs as the Y-direction moving table 4 moves, an object to be measured with good flatness, such as an A-dimensional flat, is measured and stored in advance by the optical sensor 6, and the 7 of the surface of the object W to be measured from the caulking device
A device for correcting heights in directions is used to store the heights in seven directions at three points on the surface of the object W to be measured by the output of the optical sensor 6, and calculate the value in which the heights in seven directions at these three points are equal. A function to correct so as to output the height of any other arbitrary point in seven directions when the measured object W is virtually replaced so that
It has a function to output the positions of contour lines in seven directions from the height in the Z direction.

Further, the output point of the optical sensor 6 at a certain point in time is stored, and the stored value is compared with the output value of the optical sensor 6, and the motor 14 of the seven-direction moving table 13 is determined so that the output value of the optical sensor 6 almost matches.
It is equipped with a function to control the seven directions (C/position) of the optical sensor 6 by driving the optical sensor 6 to the 7 driver 16, and controls the output of the optical sensor 6 so that it is always at a nearly constant value. Things W
The heights in seven directions are determined by the sum of the output of the optical sensor 6 and the output of the seven-direction movement amount detector 15 consisting of an interferometric length measuring device,
It is now possible to obtain precise measurements over a wide range.

Therefore, in the surface profile measuring apparatus shown in FIG. There is a reflected light point Wi near the center line I of the light receiving surface 64a of
The motor 14 is driven by the 7 driver 16 so that the light beam is moved in one direction on the Z-direction moving table 13 so that the image is formed. For the movement of the optical beam 6 in 7 directions, a 7-direction movement I consisting of an interferometric length measuring device is used.
It is detected by the δ detector 15.

The X, Y, and Z direction movement amount detectors 10.11.15 detect the movement IX in the x, y, and Z directions, respectively.

Y and Z are output to the signal processor 12.

The signal processor 12 adds the displacement amount 71 determined by the optical sensor 6 and the seven-direction movement suspension 7 determined by the seven-direction movement amount detector 13,
The X and Y direction movements ax and y are taken in, and the surface shape of the object W to be measured is calculated and output.

In addition, by placing the object W to be measured on the base 1 and irradiating the light beam of the optical sensor 1 6 onto the surface of an object with good flatness, such as the A optical flat 1, The amount of deviation in seven directions of the X-direction moving table 2 and the Y-direction moving table 4 is stored in advance in the signal processor 12 as the output of the optical sensor 6, and this deviation is corrected from the value obtained by adding the above-mentioned values 7 and 7. By doing so, correct measurement values can be obtained regardless of meandering in the X-direction moving table 2 and the Y-direction moving table 4.

In addition, when the surface of the object W to be measured is a plane inclined with respect to the When the measured object W is virtually turned so that the heights of these three points in seven directions become the same value, the height of any other arbitrary point in seven directions is output. It can also be corrected.

Note that the positions of contour lines in seven directions can also be output from the height in the Z direction.

(a) Since the surface profile measuring device of the present invention is of a non-contact type, it can perform high-speed scanning and high-speed measurement. It can also be measured on rough surfaces.

(b) Since the object to be measured can be moved arbitrarily on the X-Y plane using the X-direction moving table and the Y-direction moving table, measurement can be performed over a wide area.

=11- (c) Since the optical sensor can be moved by the Z-direction moving table, high-definition measurements can be made even when the displacement in seven directions is large.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a mechanical section of a surface profile measuring device according to an embodiment of the present invention, FIG. 2 is a block diagram of its circuit section, and FIG.
The figure shows the measurement source for the optical sensor 9-, and FIG. 4 is an explanatory diagram without showing an example of the light-receiving element.
...Pulse motor, 4...Y direction movement table, 5...Pulse motor, 6...Light sensor 9", 10...X direction movement amount Detector, 11...
... Y direction movement 171 detector, 12 ... signal processor, 13 ... Z direction movement table, 15
...Z-direction moving detector, 16...7
Driver, 61... Light source, 64... Light receiving element, 65... Arithmetic unit. Patent applicant Anritsu Electric Co., Ltd. 12-

Claims (3)

[Claims] (1) An X-direction moving table that moves the object to be measured in the X-direction: X that detects the amount of movement X of the X-direction moving table.
a directional movement amount detector; a Y-direction moving table for moving the object to be measured in a Y direction perpendicular to the X direction; a Y-direction moving 3M detector for detecting the movement amount Y of the Y-direction moving table; an optical sensor that outputs a distance change Z1 to the surface of the object to be measured in the Z direction perpendicular to the X-Y plane by irradiating the object surface with a light beam and detecting the position change of the reflected light point; A surface shape measuring device comprising: a signal processor that receives the output z1 of the optical sensor and the outputs X1Y of the X-direction movement amount detector and the Y-direction movement amount detector, and calculates and outputs the surface shape of the object to be measured. (2) an X-direction moving table that moves the object to be measured in the X direction; an X-direction movement amount detector that detects the amount of movement X-oA of the X-direction moving table;
a Y-direction moving table that moves in the Y direction perpendicular to the Y direction; a Y-direction movement amount detector that detects the movement of the Y-direction moving table;
an optical sensor that outputs a distance 11111 change fiiZ1 to the surface of the object to be measured in the Z direction orthogonal to the X-Y plane by detecting the (/ hfl change of the reflected light point; a 7-direction moving table to be moved; a Z-direction movement amount detector for detecting the movement amount Z of the Z-direction movement table; and an output Z1 of the optical sensor and an output Z of the 7-direction movement detector. a signal that calculates a change in height of the surface of the object to be measured in the Z direction, receives the outputs X1Y of the X-direction movement amount detector and the Y-direction movement amount detector, and calculates and outputs the surface shape of the object to be measured. Surface shape measuring device equipped with processing equipment. (3) The surface shape measuring device according to claim 2, wherein the optical sensor is moved by the Z-direction moving table so that the output cuff 1 of the optical sensor particles always has a constant value. 2-