JPS6024068Y2 - Array type ultrasound probe - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an array type ultrasonic probe.

An array type ultrasonic probe is constructed by arranging transducer elements made of an electrostrictive material and having electrodes provided on the front and back surfaces, for example, to form a linear array.

In this case, normally, individual electrodes corresponding to the individual transducer elements are provided on the front surface of a single electrostrictive plate of the same size as the array, a common electrode is provided on the back surface, and further, individual electrodes corresponding to the individual transducer elements are provided on the back surface. In order to improve the isolation between
Grooves of appropriate depth are cut in the electrostrictive plate between the individual electrodes.

In such array-type ultrasonic probes, it is difficult to accurately control and cut the depth of the grooves between the transducer elements, and it is actually easier to separate the individual transducer elements. be.

However, in this case, the common electrode on the back side is also separated, which is troublesome because it is necessary to connect the common electrode with a lead wire in advance or to connect it with a lead wire later.

Furthermore, if a wrap-around electrode or the like is used as the common electrode, the effective area of the vibrator will be reduced, which is disadvantageous since the value of the apparent coupling constant will be lowered.

An object of the present invention is to provide an array-type ultrasonic probe that can easily maintain electrical connection of a common electrode even if the vibrating elements are separated.

In the present invention, the backing member of the vibrator array is constructed using a conductive material, and the backing member also serves as an electrical connection between common electrodes.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a conceptual diagram of an embodiment of the present invention.

In FIG. 1, TD is a transducer array, d is an individual transducer element, and B is a conductive backing member.

On the front and back surfaces of each vibrator element d, l pairs of electrodes e,
e' is provided.

The individual transducer elements d are separated by grooves S.

The backing member B is fused to the back surface of each vibrator element d to support them.

The backing member B is made of, for example, epoxy resin mixed with fine tungsten powder at a high concentration and has conductivity, and its conductivity commonly connects the electrodes e' on the back surfaces of the individual vibrator elements d. At the same time, due to its acoustic properties, it absorbs ultrasonic vibrations generated on the back surface of each transducer element d.

Note that the backing material B can also function as a common electrode, so the electrode e' on the back surface of each vibrator element d
may be omitted.

Such an ultrasonic probe can be easily manufactured, for example, in the following manner.

An outline of the process is shown in FIGS. 2 and 3.

First, place the electrostrictive plate P, which has an electrode layer on its surface (the electrode layer may or may not be provided on the back side), on the bottom of the mold M with the electrode layer facing down, and then , epoxy resin E mixed with fine tungsten powder is injected.

If left in this state, the epoxy resin E will fuse to the electrostrictive plate P and begin to harden, but during this time the fine tungsten powder will settle downward due to gravity, so when hardening is completed, the tungsten concentration will be higher towards the bottom. A backing member is formed.

Centrifugal force may be applied to promote precipitation of the fine tungsten powder.

When the epoxy resin has sufficiently hardened, the mold M is removed, and the excess epoxy resin portion, that is, the portion where the tungsten concentration is low, is cut out and a regular backing material B is molded.

Next, grooves are cut from the surface of the electrostrictive plate P with a cutter at appropriate pitches so as to reach the backing material B, thereby obtaining individually separated vibrator elements d as shown in FIG.

Even if the transducer elements d are separated by the grooves, the fixing force of the backing member B holds the transducer array without disassembling it.

After that, the backing member B and the individual transducer elements d
The basic configuration of the ultrasonic probe is completed by attaching a lead wire to the surface electrode e.

In such an ultrasonic probe, the individual transducer elements can be completely separated, making it easy to cut grooves for isolation. is secured without any wiring work.

The backing member may be any resin molded material mixed with conductive material particles, and is not limited to the combination of fine tungsten powder and epoxy resin as shown above, and may be any other flexible material. Natural or artificial rubber or plastics that can be cast or cast, heavy metal powders,
An appropriately selected combination can be advantageously utilized in carrying out the present invention, such as powder of a high specific gravity object and a conductive film deposited on its surface.

In addition to the PZT plate that is commonly used for the purpose, the vibrator can also be made of multicomponent piezoelectric ceramics such as PCM, or lead titanate, lead metaniobate, etc., mixed with appropriate impurities. A single-component ceramic or the like can be used.

Of course, single crystals can also be used.

Furthermore, in order to improve the above structure, the depth of the groove between the vibrator elements may or may not reach the backing member;
In short, you can cut grooves without worrying too much about accuracy regarding depth.

[Brief explanation of drawings]

FIG. 1 is a conceptual block diagram of an embodiment of the present invention, and FIG. 2 is a diagram showing an example of the manufacturing process of an ultrasonic probe. TD----- Vibrator array, d... Vibrator element, B... Backing member, M...
...Injection type.

Claims (2)

[Scope of utility model registration request] (1) A backing member made of a resin molded body mixed with conductive particles to give conductivity, and this backing member is fused to the back side and an electrode layer is provided on the front side, and each vibration An array-type ultrasonic probe equipped with a transducer array in which child elements are isolated by grooves. (2) An array-type ultrasonic probe according to claim 1 of the utility model registration claim, wherein the conductive material particles are tungsten powder.