JPS6133438B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a high frequency ultrasound probe.

BACKGROUND ART Recently, ultrasonic tomography devices that can be used as medical devices to view tomographic images of the abdomen and the state of mind of working people in real time have been rapidly becoming popular. This is because these methods are non-invasive and can obtain tomographic images of a living body with a large amount of information without any danger.
Ultrasound diagnostic methods include pulse reflection method, Doppler
The pulse reflection method is currently in practical use and is in increasing demand. The principle of pulse reflection method is based on the ultrasonic vibrator (piezoelectric element).
An ultrasonic pulse of 1MHz to 10MHz is emitted, and echoes due to impedance mismatch are received from the interface of tissues (substances) with different acoustic impedances using the same transducer. By applying brightness modulation and displaying the position and intensity of echoes, it is possible to obtain tomographic images of living bodies, etc.

The important characteristics of this ultrasonic probe are sensitivity and resolution. Good sensitivity means that the size of the echo is large relative to the emitted signal, and good resolution means that the echo carries a large amount of information. In order to increase this resolution, two things are important; one is to shorten the wavelength. The speed of sound in living organisms is approximately
If the frequency is 1MHz at 1500m/s, the wavelength is 1,
5 mm, so in order to see small tissues in living organisms, it is necessary to increase the frequency and shorten the wavelength.
Frequencies between 2 and 5 MHz are generally used. Another is to speed up the attenuation of oscillation and echo pulses. Generally, the Q of a vibrator (piezoelectric element) is high, so in order to speed up the damping, the vibrator and backing material are attached to a material with a low Q such as rubber. This bucking machine prevents echoes from the living body that have absorbed sound waves toward the rear of the vibrator (piezoelectric element) from intersecting with echoes from the bucking material side. Furthermore, increasing the frequency in order to increase the resolution has the disadvantage that the attenuation of the ultrasonic waves in the living body increases and the echo signal becomes smaller. However, the current trend is for frequencies to become higher due to the development of control electronic circuits. On the other hand, the higher the frequency, the thinner the vibrator needs to be.
This is to match the resonant frequency in the thickness direction of the vibrator to the operating frequency. Furthermore, from the relationship between piezoelectric characteristics and acoustic characteristics, it has been found that the highest efficiency is achieved when the relationship between the thickness and width of the vibrator is approximately 0.6. Therefore, as the frequency increases, the thickness of the resonator becomes 5 MHz and the width of 100-odd microns becomes very small, about 200 microns.

An object of the present invention is to provide a structure that is easier to manufacture by bonding such a small, thin vibrator to a backing material. Embodiments of the present invention and conventional examples will be described below based on the drawings. Figure 1 shows the general structure of a probe. 1 shows electrodes 2 on the front and back sides.
The vibrator is made of a plurality of piezoelectric elements divided into elements and is attached to the backing material 3. Electrical connections from the electrodes are made using a common electrode of the ground electrode 5 on the top surface, and are connected to the individual electrodes from the backing material side with leads 4. In addition, because of the way it is made, a single piezoelectric vibrator is pasted onto a backing material and then divided into m sections using a cutter, so the backing material also has grooves like the number 6. Generally, electrical signals are generated by vibrating several adjacent oscillators in parallel. Therefore, the leads 4 are used by connecting several leads. The individual leads 4 must be made very small as the piezoelectric vibrator becomes smaller, and small and thin leads such as flat cables have been used until now. However, there is a limit to how small it can be.

The ultrasonic probe of the present invention can be manufactured even if it is small, and an embodiment thereof is shown and explained in FIGS. 2, 3, and 4. FIG. 2 is a perspective view of the backing material 7, in which a plurality of depressions 9 are first formed on the surface 8 to which the vibrator is bonded. Reference numeral 10 denotes a lead extraction recess formed in communication with the recess 9.

FIG. 3 is a cross-sectional view of the vibrator 11, which has electrodes 11a and 11b on both sides, and is bonded to the backing material 7, and is bonded with a conductive adhesive. Keep it filled. FIG. 4 is a sectional view when the vibrator 11 is divided by a cutter, and the grooves 13 of the cutter are cut deeper than the surface of the backing material 7 and shallower than the bottom of the depression 10. At least one groove 13 is provided for each depression 10. In the figure, two are provided. In this way, three electrical connections of the lower electrodes of the vibrator 11 can be made at once in the case shown in the figure, and if the lead wires are buried in the recess 10, the output can be taken out to the outside.

As described above, the present invention makes it possible to miniaturize the probe to a shape that was previously impossible by providing a structure in which the backing material is provided with a recess, and it is also possible to obtain a small-sized probe relatively easily.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the general structure of an ultrasound probe, and FIGS. 2, 3, and 4 show an ultrasound probe according to an embodiment of the present invention. 2
The figure is a perspective view of the backing material, and FIGS. 3 and 4 are cross-sectional views of the same ultrasonic probe. 7... Bucking material, 8... Vibrator bonding surface,
9, 10... recess, 11... vibrator, 11a, 11
b... Electrode, 12... Conductive adhesive, 13... Groove.

Claims (1)

[Claims] 1. A recess is formed on the vibrator attachment surface of the backing material, the recess is filled with a conductive adhesive, and a vibrator with electrodes provided on both upper and lower surfaces is placed on the vibrator attachment surface. An ultrasonic probe characterized in that the transducer is bonded to the conductive adhesive, and the transducer is formed with at least one groove that reaches the conductive adhesive in each of the recesses. 2. The ultrasonic probe according to claim 1, wherein a recess for inserting a lead wire is formed in communication with the recess, and a conductive adhesive is also placed in this recess to attach the lead wire. .