JPH0854203A - Apparatus for measuring plane shape - Google Patents

Abstract

PURPOSE:To realize an accurate measurement by providing means for standing an object along the vertical plane and supporting the object at several points on the circumference thereof, and means for shifting a measuring secsor in parallel with the plane of the object. CONSTITUTION:Stabilization rolls 14, each having a groove to receive the circumferential fringe of a work W, are formed on a truck 12 while being arranged accurately in parallel to each other. Right and left feed pitches are set equal constantly and the work W is elevated or lowered by means of a cylinder 15. The work W is made to abut on stoppers 15a, 16a and 17a and then a pressurization mechanism 17 is driven to impart a pressure F to the work W thus securing the work W by means of securing mechanisms 15, 16b and 17. A single shaft air slider shaft 18 is disposed contiguously to the mechanism 17 and an air slider, mounting a measuring mechanism 20, is mounted movably on the shaft 18. The air slider 19 is moved when an endless belt 22 is driven by an output from a driving section 21 and a sensor 23, mounted on the measuring mechanism 20, measures the work W.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar shape measuring apparatus, and more particularly, to a planar shape measuring apparatus for planarly measuring a surface shape such as a polishing plate of a silicon wafer. Regarding measuring device.

[0002]

2. Description of the Related Art A conventionally known apparatus for measuring the planar shape of a plate-like object is a plate-like object to be measured, a so-called work.
There is a device of the type that directly puts the surface on a surface plate for measurement, or a device of the type that supports three points on a concentric circle to measure the surface shape. For example, as shown in FIG. 10, in a measuring device with three-point support, the deformation along a straight line X ₁ connecting the center of each support point on the concentric circle and the center is within the concentric circle. The bending stress W _a in the downward direction is distributed along a quadratic curve, and the stress W _{u in the} upward direction is distributed along a quadratic curve outside the concentric circle. Further, at X ₂ connecting the center to the intermediate position between the respective support points, the bending stress distribution is a curve that appears as if a bending moment acts on the free end of the cantilever within the concentric circle. Further, in an apparatus of a type in which a work as shown in FIG. 11 is placed directly on a surface plate for measurement, it is difficult to make the upper surface of the surface plate more flat, and a ceramic polish is used. It is difficult to make the surface of an object to be measured, such as a plate, that comes into contact with the surface plate flatter. As a result, the object to be measured such as the surface plate and the ceramic polish plate is substantially supported at three points.

An outline of the measuring device will be described with reference to FIG. As shown in the figure, this device
One displacement sensor is provided on the slider shaft, and the plane information for each line is detected by linearly moving the displacement sensor. That is, the air-slider shaft 2 is horizontally arranged above the bed 1, and a small space is formed below the air-slider shaft 2. The air-slider shaft 3 is attached to the air-slider shaft 2.
The slider 3 is made movable to the air-slider shaft 2 by the motor 4 and the timing belt 6, and the displacement due to the movement is detected by the rotary encoder 7. A sensor 5 for detecting the planar shape is attached to the slider 3.

The work W is placed on the bed 1 and arranged in the space below the air-slider shaft 2. In the figure, reference numeral 8 indicates a personal computer as an arithmetic unit, and reference numeral 9 indicates a printer.

In this apparatus, while moving the slider 3 along the air-slider axis 2, the surface shape of a plate-like work W such as a polish plate, that is, along the straight line X ₃ shown in FIG. The detected shape information is combined with the position detection information to obtain the planar shape information shown in FIG. Next, as shown in FIG.
15 degrees, measure the shape on the straight line X ₄ again, and
The plane shape information of the work W shown in is obtained.

[0006]

In the conventional device as described above, the shape of the work surface is measured while the work is still flexibly deformed, and an accurate flat surface is obtained. There was a technical problem that it was not possible to obtain shape information. . This problem becomes particularly noticeable in the measurement of the polish plate which has recently become large in size, and today, improvement of the apparatus is desired in order to improve the measurement accuracy. The present invention has been made to solve the above problems, without being affected by flexural deformation due to the weight of the work,
It is an object of the present invention to provide a relatively inexpensive measuring device that can measure extremely accurately.

[0007]

In order to achieve the above object, a plane shape measuring apparatus according to the present invention comprises a sensor for measuring the plane shape of an object to be measured and the object to be measured along a vertical plane. And a means for supporting and fixing several points around the object to be measured, and a moving means for moving the measurement sensor parallel to the plane of the object to be measured.

[0008]

According to the plane shape measuring apparatus of the present invention,
Since the work is held upright along the vertical surface and the shape of the plane is measured, there is no influence of strain due to the weight of the work, and the device of the present invention also complicates the mechanism of the device. Without, accurate measurement is possible.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the apparatus according to the present invention will be described below with reference to FIGS. As shown in FIG. 1, this apparatus 10 has a trolley 12 with a roller mounted on a track 13 on a bed 11, and between the trolleys 12, 12 is a polish plate work station. The track W is mounted in a direction along a plane orthogonal to the length direction of the track 13.

Stabilizing rolls 14 and 14 having grooves for accommodating the periphery of the work W are formed on the carriages 12 and 12, and these rolls 14 and 14 are precisely arranged in parallel.
The left and right feed pitches are always the same.

The stable rolls 14 and 14 are mounted on the carriage 12.
On the top, the work W can be raised and lowered by a cylinder 15 such as a hydraulic pressure.
That is, after mounting the work W on the stable rolls 14 and 14, the work W is moved to the measurement position by the carriages 12 and 12 and brought into contact with the stoppers 15a, 16a and 17a. Then, the cylinder 15 is contracted to reach the measurement position.
After lowering W, the pressing mechanism 17 and the fixing mechanism 15,
The work W is fixed by 16b by so-called three-point support.
That is, after the work W is brought into contact with the stoppers 15a, 16a, 17a, the pressing mechanism 17 is driven to apply the pressing force F to the work W, and the fixing mechanisms 15, 16b and the pressing mechanism 17 are provided. It is something to fix with.

Assuming that the work W has a coefficient of static friction with the pressurizing mechanism 17 and a mounting angle θ of the pressurizing mechanism 17, a frictional force (work) in the measuring direction of the work W at the point A is obtained. The holding force P is represented by P = μFCOSθ. Similarly,
If the static friction coefficient between the work W and the fixing mechanism 16b is μ ′, the work holding force Q at the point B is Q = μ′FCOS
It is represented by θ. The work holding force R at point C is
The coefficient of static friction between the work W and the fixing mechanism 15 is μ ′, and the work W is
Let Wg be the own weight of R = μ'Wg + μ'FSINθ
It is represented by. As can be seen from this, the holding force P, Q, R can be set to a predetermined value so that the work W can be firmly fixed against the external force such as vibration by fixing the size of F. good.

Further, the stoppers 15a, 16a, 17
a is formed on the moving surface of the air-slider 19 described later, in other words, in the plane parallel to the air-slider axis 18. Therefore, when the work W is fixed by the pressing mechanism 17 and the fixing mechanisms 15 and 16b, the work W is arranged in parallel with the air-slider shaft 18. still,
Reference numeral 16 in the figure is a safety mechanism for preventing the work W from falling down unexpectedly. It is formed so as to be rotatable about one axis.

A uniaxial type air-slider shaft 18 is arranged adjacent to these fixing mechanisms, and an air-slider 19 is movably mounted on the air-slider shaft 18 and is mounted on the air-slider 19. The measuring mechanism 20 is mounted.

That is, the air-slider 19 is moved along with the air-slider shaft 18 by driving the endless belt 22 by the output of the driving portion 21, and the measuring mechanism 20 has -The two sensors 23 having the contacts that come into contact with the surface of
The plan shape of the work W is measured by 3. Although not shown in the figure, this device is also provided with a rotary encoder as in the conventional device so that the position information of the air slider 19 can be detected by the rotary encoder. There is. Similarly, a personal computer for calculating surface shape information obtained from the sensor 23 mounted on the air slider 19 and position information obtained from the rotary encoder, a printer for printing the obtained information, and an air printer. A control unit that controls a drive system such as the slider 19 is provided.

The work W and the air-slider 19 are arranged parallel to each other as described above. In order to further increase the parallelism, the movement line of the air-slider 19 and the work line are shown in FIG. -It is necessary to carry out parallel adjustment with W. The adjustment mechanism for this is also installed. In this adjusting mechanism, a fulcrum 26 is provided on the air-slider shaft 18, and a push plate 18a attached to the air-slider shaft 18 at the other end is rotated by an adjusting screw (not shown) so as to resist the spring unit 25. Then, the air-slider shaft 18 draws an arc and moves slightly. The fine movement distance is measured by the micrometer 24.

Next, the adjusting method of the adjusting mechanism will be described. First, the sensor 23 measures the distance between one point (point P) on the work W and the air-slider shaft 18. Then, the air-slider 19 is moved to another point (Q
The distance at the point) is measured in the same manner. Here, since the distances of the P point and the Q point from the fulcrum 26 can be detected by the rotary encoder, the air-slider 1 can be detected from these relationships.
The inclination angle between 8 and the work W can be calculated.

That is, assuming that the distance d from the point P to the air-slider shaft 18 is b, the distance from the fulcrum 26 is b, the distance y from the point Q to the air-slider shaft 18 is a, and the distance from the fulcrum 26 is a. θ = tan ⁻¹ (ye / ba). Therefore, by rotating the air-slider shaft 18 by the angle θ about the fulcrum 26, the work W and the air-slider shaft 18 can be made parallel to each other. The movement amount Y of the micrometer head 24 can be obtained by multiplying the distance X from the fulcrum 26 by the above-mentioned θ.

Further, in this apparatus, the measuring mechanism 20
When the external force of the electric wire 28 connected to the air supply tube 27 or the sensor is applied to the measuring mechanism 20, the measuring mechanism 20 causes a minute fluctuation, which causes a measurement error. In order to prevent this, a slide shaft 29 is provided in parallel with the air-slide shaft 18, and at the same pitch as the pulley 22 coaxially with the pulley 22 that drives the measuring mechanism 20 (air-slider 19). In addition to forming the pulley 30, there is provided a slide base 32 that always moves at equal intervals with the measurement mechanism 20 (air-slider 19) by the timing belt 31 having the same pitch and the same size.
By fixing the tube 27 and the electric wire 28 to the slide base 32, the external force of the tube 27 and the electric wire 28 is received by the slide base 32 so that no force is applied to the measuring mechanism 20. .

After the setting of the work W is completed, the slider 19 is moved along the air-slider shaft 18 while the contact of the sensor 23 measures the planar shape of the work W. Although not shown in this embodiment, the position information of the air-slider 19 and the surface shape information obtained from the sensor 23 are calculated by a calculation unit to obtain plane information of the entire work W. be able to.

Further, the work W is rotated, for example, by 45 degrees, and the measurement by the sensor 23 is performed again in the same manner as described above, and the surface of the work W is measured from the plane information and the position information.

As described above, the work W is placed in a state along the vertical plane to measure the surface shape.
Work W such as polish plate that has reached over kg
Can be accurately measured without being affected by its own weight.

Next, the measurement work using the apparatus of the present invention will be described in detail. First, as shown in FIG.
After the position is set so that the center O of the black W is on the moving line of the sensor 23, the straight line G0H and the straight line IQJ are traced by the sensor 23. At this time, Z is two sensors 23, 2.
The intervals are 3.

Further, the work W is rotated by 90 degrees as shown in FIG.
Information on the surface shape along the QOL and the straight line MPN is obtained. At this time, before and after rotating the work W by 90 degrees,
Although it depends on the surface shape of the work W and the contact state with the fixing mechanism, the information of G0H of the measurement result and the height information of O of the measurement result KQOL are matched, and
By matching the height information of Q on the straight line IQJ and the straight line KQOL, the data obtained by the two sets of sensors 23, 23 will be converted into the data on the same reference plane.
The measurement curve at this time is shown in FIG. The above data
As shown in FIG. 9, the surface shape of the work W can be three-dimensionally obtained from the data.

[0026]

As is apparent from the above description, according to the measuring method of the present invention, since the work is measured in the vertical state, there is no deformation due to the weight of the work itself, and the work is relatively accurate. The shape of the surface can be measured.

[Brief description of drawings]

FIG. 1 is a front view of a planar shape measuring apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a plan view of FIG.

FIG. 4 is a schematic view of an adjusting mechanism according to the planar shape measuring apparatus of the present invention.

FIG. 5 is a diagram illustrating an adjusting method by the adjusting mechanism shown in FIG.

FIG. 6 is an explanatory view showing a measuring process by the measuring apparatus of the present invention.

FIG. 7 is an explanatory diagram showing a measuring process by the measuring apparatus of the present invention.

FIG. 8 is an explanatory diagram of measurement results by the measuring device of the present invention.

FIG. 9 is a three-dimensional perspective view of a measurement result by the measuring device of the present invention.

FIG. 10 is an explanatory diagram showing a deformed state of the work in a measurement state by the conventional method.

FIG. 11 is a perspective view of a conventional measuring device.

FIG. 12 is an explanatory diagram showing a measurement process.

FIG. 13 is a curve diagram showing a measurement result by a conventional measuring device.

FIG. 14 is an explanatory diagram of a measurement process further performed by a conventional measurement device.

15 is a curve diagram corresponding to the measurement process shown in FIG.

[Explanation of symbols]

 11 bed 12 bogie 13 orbit 14 roller 15 fixing mechanism 16b fixing mechanism 17 pressurizing mechanism 18 air-slider shaft 19 air-slider 20 measuring mechanism

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuaki Kamiashi 30 Soya, Hadano City, Kanagawa Prefecture, Toshiba Ceramics Co., Ltd. (72) Inventor Shiro Majima 30 Soya, Hadano City, Kanagawa Prefecture, Toshiba Ceramics Co., Ltd.

Claims (1)

[Claims] 1. A sensor for measuring a planar shape of an object to be measured.
And, while standing up the measured object along a vertical plane,
A plane-shaped measuring device comprising: a means for supporting and fixing several points around an object to be measured; and a moving means for moving the measurement sensor in parallel to the plane of the object to be measured.