JPH04296633A - Two-parallel-springs stylus structure body - Google Patents

Abstract

PURPOSE:To measure surface hardness distribution nondestructively by providing a piezoelectric element as a separating member at an end part of two-parallel- springs equipped with a stylus so as to drive by supersonic frequency voltage, and measuring propagated vibration with a supersonic sensor. CONSTITUTION:On a longitudinal stylus structure body 9, conductive plate spring 2, 3 are held in parallel by a piezoelectric element 4, an insulating body 5 and a stylus 1 are provided nearby the element the springs 2, 3 are fixed to an insulating base 8 together with the insulating body 5, and piezoelectric element drive power sources 6, 7 are connected to the springs 2, 3 at the outer end of insulating body 5. An AC voltage is applied to the structure body 9 from the power sources 6, 7 so as the stylus 1 to generate supersonic vibration, and a face to be measured is scanned by moving an object to be measured 10. Then the output of a supersonic sensor 11, fixed to the end part of the object to be measured 10, is recorded as the supersonic propagated output from the stylus 1. As the supersonic propagated output reflects the hardness distribution of the face to be measured, the hardness distribution in response to the contour of the face to be measured can be measured by one time scanning at the same time together with the surface contour.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stylus structure for measuring physical quantities on the surface of an object.

0002

[Prior Art] Conventionally, in order to measure physical quantities on the surface of an object, a stylus with a sharp tip is attached to a leaf spring, the stylus is pressed against the measuring surface with a minute load, while the measuring surface is moved within the measuring surface.
This movement of the stylus is detected by a displacement sensor, and the attraction force, frictional force, surface shape, etc. of the measurement surface are measured. As tribological information on such measurement surfaces, it is desired to newly measure physical quantities such as surface hardness distribution. Therefore, the surface was scanned several times with a stylus under a constant load, and the hardness distribution of the surface was measured from changes in the worn shape.

0003

[Problems to be Solved by the Invention] In the conventional stylus structure described above, when measuring a physical quantity such as the hardness distribution on the surface, it is necessary to destroy the sample and at the same time touch the measuring surface several times to several tens of times.
The disadvantage is that it is time consuming because it has to be scanned several times.

[0004] An object of the present invention is to provide a stylus structure capable of measuring surface hardness distribution, etc. in a short time without destroying the measurement surface of a sample.

[0005]

[Means for Solving the Problems] The two-parallel spring stylus structure of the present invention has two rectangular leaf springs made of conductive material located parallel to each other, the end of the leaf spring facing the measurement surface. The part is equipped with a stylus with a sharp tip facing the measurement surface, and 2
Of the two members that separate and hold the leaf spring at both ends in the longitudinal direction of the leaf spring, the stylus side member is formed of a piezoelectric material as a piezoelectric element, and the other end side member is formed of an insulating material. The piezoelectric element is fixed to an insulating base together with the leaf spring, and an ultrasonic frequency power source for driving the piezoelectric element is connected to each of the two leaf springs near a portion fixed to the base.

[0006]

[Operation] When the piezoelectric element is driven by an ultrasonic frequency power source, the vibration generated propagates to the stylus and causes the stylus to vibrate. Surface hardness can be measured by measuring ultrasonic vibrations.

[0007]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of the two-parallel spring stylus structure of the present invention, FIG. 2 is a side view of a measurement system using the two-parallel spring stylus structure of FIG. 1, and FIG. is a rough graph showing the hardness distribution of the object surface measured by the measurement system of FIG.

This two-parallel spring stylus structure includes leaf springs 2,
3, a piezoelectric element 4, an insulator 5, and a base 8. The leaf springs 2 and 3 are both formed into rectangular shapes made of conductive material and are positioned parallel to each other, and a stylus 1 is provided at one end of the leaf spring 2 facing the measuring surface. The stylus 1 has a sharp tip. The piezoelectric element 4 is attached to the end of the leaf spring 2 where the stylus 1 is provided, and holds the leaf springs 2 and 3 in parallel and spaced apart. The insulator 5 connects the leaf springs 2, 3 near the other ends of the leaf springs 2, 3.
3 are held parallel and spaced apart, and are fixed together with the leaf springs 2 and 3 to a base body 8 formed of an insulating material. Power supplies 6 and 7 for driving piezoelectric elements are connected to the outer ends of the insulators 5 of the leaf springs 2 and 3, respectively. When an AC voltage with an ultrasonic frequency is applied from the piezoelectric element driving power supplies 6 and 7, the applied voltage drives the piezoelectric element 4 via the leaf springs 2 and 3, and the ultrasonic vibrations generated by the piezoelectric element 4 are transmitted to the stylus. 1 and causes the stylus 1 to vibrate.

[0010] With this two-parallel spring stylus structure, the surface hardness distribution of the measurement surface can be measured in one scan, so not only does it not destroy the sample, but it can also be measured in a short time. Since the ultrasonic vibrations are applied from the position, the propagation efficiency of the ultrasonic vibrations is high, and there is no difference in the amount of vibration propagation depending on the material, dimensions, etc. of the spring portion serving as the propagation medium.

Next, an example of the use of this two-parallel spring stylus structure will be explained.

The measurement system shown in FIG. 2 is composed of the two-piece parallel spring stylus structure 9 shown in FIG. The ultrasonic sensor 11 is attached to the end of the object 10 placed on the X-axis moving table 13. The X-axis moving stage 13 moves the object 10 to be measured in the X-axis direction on the surface to be measured. The Y-axis moving table 14 moves the object 10 to be measured in the Y-axis direction on the surface to be measured. The displacement sensor 12 detects the displacement of the stylus 1 in the Z-axis direction perpendicular to the surface to be measured from above the object 10 to be measured.

In order to measure the hardness distribution corresponding to the surface shape of the surface to be measured of the object 10 using this measurement system, the two parallel spring stylus structure 9 is powered by 355k from the piezoelectric element driving power supplies 6 and 7.
A Hertz AC voltage is applied to generate ultrasonic vibrations in the stylus 1, and then the surface to be measured of the object 10 is scanned by moving the X-axis moving table 13 and the Y-axis moving table 14. The output of the displacement sensor 12 at this time is recorded as the surface shape output of the surface to be measured, while the output of the ultrasonic sensor 11 is recorded as the ultrasonic propagation output from the stylus 1. The ultrasonic propagation output reflects the hardness distribution of the surface to be measured, and in the case of low hardness, the amount of ultrasonic propagation from the stylus 1 to the ultrasonic sensor 11 is reduced, and in the case of high hardness, the amount of ultrasonic propagation is reduced. increase Therefore, in combination with the output of the displacement sensor 12, the hardness distribution corresponding to the surface shape of the surface to be measured can be measured non-destructively and at the same time as the surface shape.

[0014] Furthermore, since the minute displacement due to ultrasonic vibration applied to the stylus 1 is on the high frequency side compared to the output of the displacement sensor 12 corresponding to the surface shape, its influence can be easily removed by a low-pass filter. However, since the ultrasonic vibration displacement is very small, if the surface shape displacement output is large, it is possible to directly measure the displacement output without using a filter.

Next, a specific example showing the effects of this embodiment will be explained.

FIG. 3 shows the results of one-dimensional scanning of a surface to be measured on which a resist pattern is printed on a silicon substrate using the measurement system shown in FIG. In this graph, the ultrasonic sensor output decreases in the portion of the surface to be measured where the photoresist is present, and the ultrasonic output increases in the portion where the silicon substrate surface is exposed. In other words, it can be seen that this data reflects the difference in hardness between the photoresist and silicon.

[0017]

Effects of the Invention As explained above, the present invention provides a piezoelectric element as a separation member at the end of two parallel leaf springs equipped with a stylus, and drives it with an ultrasonic frequency voltage, so that the object to be measured can be The attached ultrasonic sensor measures the propagating vibration and the surface hardness distribution can be measured in one scan, so the measurement can be done in a short time without destroying the sample, and ultrasonic vibrations are generated from the position closest to the stylus. Therefore, there is an effect that the vibration propagation efficiency is high and that there is no variation in the amount of vibration propagation due to the material, dimensions, etc. of the spring portion.

[Brief explanation of drawings]

FIG. 1 is a perspective view of one embodiment of the two-parallel spring stylus structure of the present invention.

FIG. 2 is a side view of a measurement system using the two-parallel spring stylus structure of FIG. 1;

FIG. 3 is a rough diagram showing the hardness distribution of the object surface measured by the measurement system of FIG. 2;

[Explanation of symbols]

1 Stylus 2, 3 Leaf spring 4 Piezoelectric element 5 Insulator 6,7　　　　Piezoelectric element drive power supply 8 Base 9 Two parallel spring stylus structure 10 Measurement object 11 Ultrasonic sensor 12 Displacement sensor 13 X-axis moving table 14 Y-axis moving table

Claims (1)

[Claims] 1. Two rectangular leaf springs made of conductive material located parallel to each other, the end of the leaf spring facing the measurement surface is provided with a stylus with a sharp tip facing the measurement surface, Of the two members that separate and hold the two leaf springs at both ends in the longitudinal direction of the leaf springs, the stylus side member is formed of a piezoelectric material as a piezoelectric element, and the other end side member is formed of an insulating material. and fixed to an insulating base together with the leaf spring, and each of the two leaf springs has two parallel spring contacts to which an ultrasonic frequency power source for driving the piezoelectric element is connected near the part fixed to the base. Needle structure.