JPS5899954A - Manufacturing method of ultrasonic deep probe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method of manufacturing an ultrasonic probe.

BACKGROUND ART Recently, ultrasonic tomography devices that can view tomographic images of a moving heart and abdomen in real time have been rapidly becoming popular as medical equipment. This is because it is non-invasive, has little risk, and provides a large amount of information despite its low cost. Ultrasonic diagnostic methods include the pulse reflection method, the Drabler method, and the transmission method, but the pulse reflection method is currently in practical use and is the key to research.

The principle of the pulse reflection method is that the IM
Hz to 1 oM) (A pulse of ultrasonic waves is emitted, and the same transducer receives the echoes returned from the interface of two tissues (substances) with different acoustic impedances due to impedance mismatch, and calculates the intensity of the echoes. This applies brightness modulation to the oscilloscope and displays the location of the echo.

There are two types of diagnostic equipment: a mechanical scanning method and an electronic scanning method, but there is a tendency to standardize on the electronic scanning method, which provides a large amount of information.

In the case of the electronic blurring method, there are two types: one in which only one electrode of the vibrator is divided into m pieces, and one in which the vibrator is divided into m pieces.

The important characteristics of this ultrasonic probe are sensitivity and resolution1. Good sensitivity means that the size of the echo is large relative to the emitted signal, and good resolution means that This means that the echo brings a large amount of information. There are two important things to do to increase this resolution; one is to shorten the wavelength. η
In other words, the speed of sound in a living body is approximately 1500 m/s and 1 MHz.
If the frequency is , the wavelength is 1.5 wa, so in order to see small tissues in living organisms, it is necessary to increase the frequency and shorten the wavelength. Generally 2~5MHz
frequencies are often used. Another important point is fast decay of the oscillation and echo pulses. Generally, the Q of a vibrator (piezoelectric element) is high, so in order to speed up the damping, the vibrator is attached to a backing material made of a material with a low Q such as rubber. This backing material absorbs sound waves toward the rear of the vibrator, and prevents echoes from the living body from intersecting with echoes from the backing material side. Furthermore, if the frequency is increased in order to increase the resolution, the attenuation of the ultrasonic waves in the living body increases, which has the disadvantage that 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 done by matching the resonant frequency in the thickness direction of the vibrator to the operating frequency, and from the relationship between piezoelectric characteristics and acoustic characteristics, the relationship between the thickness of the vibrator and IJ is W/T = o
,s (Tatashi, W-ri.

It is known that the efficiency is highest when the thickness is T-thickness.

Therefore, at 2.5MHz, the thickness of the resonator is a few tens of microns.

The width is very small, about 200μ.

A conventional example will be explained below with reference to the drawings. In FIGS. 1 and 2, reference numeral 1 denotes a vibrator consisting of a plurality of divided piezoelectric elements having electrodes 2.3 on the front and back surfaces, and is pasted on a backing material 6. For electrical connection from the electrodes 2 and 3, a common electrode 4 made of metal foil, such as a station, is attached to the top electrode 3 of the vibrator 1 by soldering or the like. 5
is a lead wire fixed to the lower electrode 2 of the vibrator 1 with a conductive adhesive or the like.

In this case, the common electrode is made of metal foil such as steel, as shown in FIG. 2, and the cross section of the common electrode is flat. In order to connect a large number of these to the vibrator having a width as small as about 200 μm, it was necessary to perform the soldering work using a microscope. Also, it is necessary to check whether the electrical connection is made after soldering, but since the common electrode is a flat plate when viewed from the top or side, even if it appears to be connected, The disadvantage was that some of the oscillators did not exhibit characteristics because they were not connected.

Furthermore, since the vibrator is divided into m pieces and the common electrodes are then connected by soldering, there are problems such as solder flowing between the divided vibrators, resulting in a short circuit.

The present invention aims to eliminate the above-mentioned conventional drawbacks and to provide a method for manufacturing an ultrasonic probe that has a simple structure and can reliably provide a common electrode.

An embodiment of the present invention will be described with reference to FIGS. 3 and 4. Here, the same numbers are given to the same parts as in the conventional example. The features of the present invention are that the vibrator 1 bonded to the punching material 6 does not have a bottom electrode 2' at one end 8 in the longitudinal direction, and - the top electrode 3 and the backing material 6 have silver After fixing the common electrode 7 made of metal foil such as the above by soldering, a part of the vibrator 1 fixed to the backing material 6 of the common electrode 7 is left and the depth up to line 9- in FIG. 4 is left. This involves cutting into m pieces using a scribing dicer (not shown).

According to the present invention, it is not necessary to use a microscope during the soldering work of the common electrode, and the common electrode can be easily formed. Since it is divided into two parts, there is an effect that there is no inconvenience caused by a short circuit.

[Brief explanation of drawings]

1 and 2 are a perspective view and a side view of a conventional ultrasonic probe, and FIGS. 3 and 4 are perspective views of a second ultrasonic probe for explaining the manufacturing method according to the present invention. FIG. 3 is a side view partially shown in cross section. 1... Vibrator, 2'... Bottom electrode, 3
...Top electrode, 6...'4 mounting material, 7...Common electrode. Name of agent: Patent attorney Toshio Nakao and 1 other person Maki 1
Figure 4 Figure 3 Figure 14

Claims (1)

[Claims] A vibrator having no electrode is attached to the lower surface of one end in the elongated direction to the backing material, and a metal foil such as silver is fixed to the upper electrode end of the vibrator and the backing material to form a circular electrode, A method for manufacturing an ultrasonic probe, characterized in that a part of the common electrode of the metal foil fixed to the banking material is left and is cut together with the vibrator to divide it into a plurality of vibrators.