JPS58118960A - Ultrasonic microscope - Google Patents

Abstract

PURPOSE:To improve the reliability, by incorporating an ultrasonic microscope in a production line for supporting a sample without contact, introducing a liquid or gas from both sides of a running sample so that it is useful for an intermediate inspection of the material production. CONSTITUTION:A sample 14 is led into a sample holding part 16 through a guide rolls 15. Into the sample holding part 16, a liquid 17 which is an ultrasonic propagating medium is adjusted to some pressure and is discharged from a discharge port 18, therefore, the sample 14 is supported stably without contact in the holding part 16 by its static pressure, and moves smoothly. When an ultrasonic beam is irradiated from a spherical lens 1 provided on its upper part, to the sample 14 supported in this way, the liquid 17 between the spherical lens 1 and the sample 14 executes the same operation as the ultrasonic propagating medium, therefore, ultrasonic waves are propagated to the sample 14 surface without a trouble, and high resolution is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic microscope, and particularly to an ultrasonic microscope that can polish a predetermined sample.

In recent years, it has become possible to generate and detect ultrahigh-frequency sound waves up to IGHz, so it has become possible to realize sound wavelengths of about 1 μm underwater, and as a result, it has become possible to obtain high-resolution sound wave imaging devices. That is, a concave lens is used to create a focused sound wave beam, achieving a high resolution of 1 μm.

Place the sample in the above beam, detect the reflected ultrasonic waves from the sample, and elucidate the elastic properties of the minute region of the sample.
By mechanically scanning a sample in two dimensions and displaying the intensity of this signal as a brightness signal on a cathode ray tube, it is possible to magnify the fine structure of the sample.

FIG. 1 is a diagram showing the main components of the ultrasound microscope. The focusing, transmission and reception of ultrasonic waves is performed by a spherical lens 1, whose structure consists of optically polishing one side of a material made of cylindrical fused silica, etc., and piezoelectric thin films (ZnO) 2 placed on top and bottom electrodes. A pulse 5 generated from a pulse oscillator 4 is applied to the piezoelectric thin film 1112 sandwiched between the piezoelectric thin film 1112 sandwiched by the piezoelectric thin film 1112 sandwiched between the piezoelectric thin film 1112 sandwiched by the piezoelectric thin film 1112 sandwiched between the piezoelectric thin film 1112 sandwiched by the piezoelectric thin film 1112 sandwiched between the piezoelectric thin film 1112 sandwiched between the piezoelectric thin film 1112 sandwiched by the piezoelectric thin film 1112 sandwiched between the piezoelectric thin film 1112 sandwiched by the piezoelectric thin film 1112 sandwiched by the piezoelectric thin film 1112 that has a sandwich structure in this way. The other end has a diameter of 0.1 wφ to 1. A concave hemispherical hole of approximately Owφ is formed, and a medium (for example, water) 8 for propagating the ultrasonic wave 6 to the sample 7 is filled between the hemispherical hole and the sample.

Ultrasonic waves 6 generated by the piezoelectric thin film 2 propagate in the cylinder as plane waves. When this plane wave is carried to the hemispherical hole, it will cause quartz (sound speed 6000m/'1) and water (sound speed 1500m/s
), a refraction effect occurs due to the difference in sound speed between the sample 7 and the sample 7, and the focused ultrasonic waves 6 can be irradiated onto the sample 7 surface. Conversely, the ultrasonic waves reflected from the sample 7 are collected and phased by a spherical lens, become plane waves, reach the piezoelectric thin film 2, and are converted into an RF signal 9 here. This RF signal 9 is received by a receiver 10, where it is diode-detected and converted into a video signal 11.
It is used as an input signal for the CR'r display 12.

In the apparatus configured in this way, when the sample 7 is two-dimensionally scanned within the x-y plane by the sample stage drive power supply 13, the intensity of reflection from the sample surface as the sample scans changes two-dimensionally as CR. , is displayed on the T-plane 12.

Generally speaking, a portion of ultrasound waves is reflected by the surface of an object, but the other part of the ultrasound wave goes into the object, regardless of whether the object is optically transparent or not. , it returns as an echo reflecting differences in viscosity and defects.

Ultrasonic beams can utilize this property to detect aspects inside a sample.

The field of application of the ultrasonic microscope with the above-mentioned characteristics is in sectors such as steel, polymer materials, and metal surface treatment. There are big advantages.

In the steel rolling process or the process where sheets of polymeric materials are continuously produced, they are continuously inspected to check for defects and variations in thickness, as well as the thickness of the gold MFF surface layer treatment film and the presence or absence of defects. Testing to detect tFF requires a large amount of processing power in testing equipment, but conventional testing methods mainly involve sampling tests, and methods that calculate the overall tFF value from the test results of a specific sample. Therefore, the reliability of the results was not sufficient, and there was also a limit to the amount of samples that could be tested.

The present invention has been made in view of these points, and is intended to provide an entire device that can be incorporated into an ultrasonic microscope production line and is effective for intermediate inspection of material production.

The details of the present invention will be described below based on the figures.

Generally, when the sample 14 is moving at a constant speed in the direction of the arrow as shown in Figure 2, if the spherical lens at point A on the surface repeats scanning in the direction perpendicular to the sample movement, this Just as described in Figure 1, where an ultrasonic beam is irradiated onto a sample surface that is scanning at a predetermined speed on the X-Y plane, information about the sample surface is projected onto a CRT screen in a bundle. be able to.

FIG. 3 shows the main components of the present invention. The sample 14 is introduced into the sample holder 16 from the left side via the guide roller 15. When a liquid 17 that provides 1M ultrasonic propagation quality is adjusted to a certain pressure and is discharged from a discharge port 18 provided at a predetermined location in the direction perpendicular to the upper and lower surfaces of the sample, the sample 14 is stably supported within the sample holder 16 without contact due to its static pressure. Further, the discharged liquid 17 acts as a buffer between the sample 14 and the guide surface of the sample holder 16, and the sample can be moved smoothly without being affected by slight irregularities on the sample surface.

As mentioned above, when the sample 14 supported by static pressure is irradiated with an ultrasonic beam from the spherical lens from above, the liquid 17 forms the ultrasonic propagation medium 7 between the spherical lens 1 and the sample 14. Because it has the same effect as the ultrasonic wave, ultrasonic waves can be propagated on the sample surface without any problems.

Although the method for holding the sample 14t by discharging the liquid 17 from the discharge port 18 of the sample holder 16 has been described above, the same effect can be obtained by discharging high-pressure gas instead of the liquid 170.

When sound waves propagate in gas, as the pressure increases, the attenuation of the sound waves decreases, and even sound waves with high frequencies can propagate.

As an example, the attenuation of sound waves in argon gas of 400 Kp/σ1 is approximately the same as in water.

However, the propagation speed is about 1500 m/s in water and about 300 m/s in argon gas, so the wavelength in gas is 115 for the same frequency, so liquid 1r is used as a medium. Higher resolution than would otherwise be achieved.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a conventional ultrasonic microscope, Fig. 2 is a diagram for explaining the present invention, and Fig. 3 is a diagram for explaining the present invention.

Claims (1)

[Claims] 1. It consists of an f-wave propagation body and a sound wave lens shaped at the end of this propagation body and having a predetermined focal point, and the sample is photographed by the disturbing sound waves emitted from the predetermined sample provided near the focal point. 1. An ultrasonic microscope characterized by having sample holding means for supporting a moving sample from both sides by static pressure of liquid or gas.