JPS58129355A - Ultrasonic microscope - Google Patents

Abstract

PURPOSE:To obtain a clear picture through removal of trailing produced thanks to a reflecting signal from a lens interface, by applying a compensating pulse to a contact making contact with a sample electrode. CONSTITUTION:A piezo-electric film 2, which is a sample and positioned between the nip formed by electrodes 3, is located on a spherical lens 1 of an ultrasonic microscope. A tip of a contact 16 attached to a ring 15 formed of an insulating material makes contact with the electrode 3, and a RF pulse signal 5 is applied through the contact 16. A terminal 17, piercing the ring 15 through a side surface, makes contact with the contact 16, and a compensating pulse 18 is applied to the terminal 17. The compensating pulse 18 is synthetized with the RF pulse 5 which removes trailing of a pulse waveform produced by reflection from a lens interface.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to ultrasonic microscopic values, particularly to an ultrasonic microscopic end capable of applying stress to an observation sample.

In recent years, it has become possible to generate and detect ultra-high frequency sound waves up to IGHz, making it possible to realize a blue wavelength of approximately 1 μm underwater, and as a result, it has become possible to obtain a high-resolution sound wave imaging device. That is, a concave lens is used to create a focused sound wave beam, achieving a high resolution of 1 μm.

By placing a sample in the beam and detecting the ultrasonic waves reflected by the sample, we can elucidate the elastic properties of minute regions of the sample.
Alternatively, if the sample is mechanically scanned in two dimensions and the intensity of this signal is displayed as a brightness signal of a CRT,
You can zoom in on the fine structure of the sample.

FIG. 1 is a diagram showing the main components of the ultrasonic 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 then placing a piezoelectric thin film (Zr1012) on top of it.
1-A pulse 5 (generated from a pulse oscillator 4) is applied to the piezoelectric thin film 2 having a sandwich structure, which is recirculated by the upper and lower electrodes 3, to generate an ultrasonic wave 6. In addition, a concave hemispherical hole with a diameter of about 0.1 mm to 1.0 mm is formed at the other end, and between this hemispherical hole and the sample, the ultrasonic waves 6 are transmitted to the sample 7. medium for making (
For example, water) 8 is filled.

Ultrasonic waves 6 generated by the piezoelectric thin film 2 propagate in the cylinder as plane waves. When this plane wave reaches the hemispherical hole, refraction occurs due to the difference in sound speed between quartz (sound speed 6000 m/s) and water (sound speed 1500 m/l).

Focused ultrasonic waves 6 can be irradiated onto the surface of the sample 7. Conversely, the ultrasound reflected from the sample 7 is collected and phased by a spherical lens, becomes a plane wave, and reaches the piezoelectric thin film 2.
Here, it is converted into an RF signal 9. This RF signal is received by a receiver 10, detected by a diode and converted into a video signal 11, which is used as an input signal to a CRT display 120.

In the companion device 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 is scanned is two-dimensionally 081. displayed on screen 12.

FIG. 2(a) ilt shows the detection signal in the video area when an RF pulse signal with a certain repetition period of 11 is applied in such a conventional configuration. Here, the horizontal axis represents the time axis, and the vertical axis represents the signal strength. A shows the applied tF pulse, and the reflected signal from the Bfl lens interface is
It also shows the reflected signal from the ch sample.

In conventional imaging equipment, in order to distinguish this desired reflected signal C from B, the duration of the applied pulse tdy is set as short as possible, the B and C signals do not overlap, and only the C signal is timed. However, even if efforts are made to shorten the duration time tdt of the applied pulse, the pulse oscillator 4 is provided on the top surface of the spherical lens!The next piezoelectric thin film 2 The pulse waveform is affected by the capacitance C + inductive inductance L that exists in the circuit between
Because something on the tail side as shown in Figure 3(b) becomes a trap, the reflected signal B from the lens interface and the reflected signal C from the sample overlap, as shown in Figure 3(b). Even if you try to extract only the C signal with a dimegut,
As a result of the B signal being included, it is difficult to obtain a clear image.

Original F! A. This was developed to solve this problem, and makes it possible to remove the tail of the waveform of the applied pulse.

FIG. 3 shows the principle of the present invention. (If you apply the R, F signal waveform A shown in (b) to the RF pulse waveform A wave with the waveform shown in →, the RF signal waveform will become as shown in (C). As is well known.

Therefore, the tail side of the RF pulse waveform can be removed by performing this operation near the piezoelectric thin film [2] where the influence of the capacitance C and inductance L existing in the circuit system is minimal. .

In addition, in FIG. 3, the f'LP waveform serving as a carrier is omitted.

FIG. 4 is a diagram showing the detailed structure in the vicinity of the spherical lens provided with the function of removing the tail side of the pulse waveform described above.

A piezoelectric thin film 2 is formed on the upper surface of the spherical groove 1 with an electrode 3 forming a sandwich structure. There is an ultrasonic transmitter and receiver. A contactor 16 is attached to the contactor 16, which is molded from an insulator and attached to a wire 15, the tip of which is connected to the electrode 3.
I have been in contact with this and it is 0M! A pulse signal 5 is applied to the electrode 3 through the probe 16.

Further, the contactor 16 has a structure in which a terminal 17 penetrates through the ring 15 and comes into contact with the contactor 16 from the side.

A signal 18 for removing the tail side of the pulse signal 5 is applied to this terminal 17.

With this configuration, in the vicinity of the pole of electrode 3, signals 5 and 18 are combined, and a waveform signal with the caudal side completely removed is applied to electrode 3. Shorter pulses can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the schematic configuration of ultrasonic microscopic values, Fig. 2 is a diagram showing the timing of signal accumulation, Fig. 3 is a diagram explaining the details of the present invention, and Fig. 4 is a diagram showing the fJ 3 of the present invention. Figure%4 Figure

Claims (1)

[Claims] Ultrasonic waves consist of a sound wave propagation body and a sound wave lens formed at the end of this propagation body and having a predetermined focus, and image the sample using electric waves emitted from a predetermined sample provided near the focus. An ultrasonic microscopic value characterized by comprising means for combining and applying a compensation pulse to a piezoelectric thin film excitation pulse at a microscopic end.