JPH0537998A - Ultrasonic probe - Google Patents

Abstract

PURPOSE:To obtain an ultrasonic probe capable of realizing high frequency. CONSTITUTION:The ultrasonic probe is provided with plural transducers 1 arrayed on a supporting board 5, lead wires 4 each of which connects the prescribed number of continued transducers 1 out of plural ones in common, the 1st fillers 11 filled in respective transducer groups, and the 2nd fillers 10 having hardness higher than that of the 1st fillers 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe in which a plurality of electro-acoustic conversion elements (hereinafter referred to as "transducers") are arranged, and particularly to an ultrasonic probe in which fine transducers are arranged. Regarding the child.

[0002]

2. Description of the Related Art An ultrasonic diagnostic method in which an ultrasonic pulse is radiated into a living body and biological information is obtained by a reflected wave from a boundary surface of tissues having different acoustic impedances is free from irradiation obstacles such as X-rays and a contrast agent It has the advantage that soft tissue can be diagnosed without it. In recent years, this ultrasonic diagnostic method has been designed to increase the frequency of ultrasonic waves in order to improve the diagnostic ability of a shallow organ, that is, to achieve high image quality and high resolution.

An array type ultrasonic probe conventionally used in an electronic scanning type ultrasonic diagnostic apparatus has a structure as shown in FIG. The conventional ultrasonic probe absorbs unnecessary ultrasonic waves other than ultrasonic waves transmitted and received in a desired direction, that is, ultrasonic waves emitted in the opposite direction to the living body, and supports the entire ultrasonic probe. Depending on the vibrations of the back load material 25 also serving as a stand, a plurality of transducers 21 arranged on the back load material 25 and having an ultrasonic wave transmitting / receiving surface for transmitting and receiving ultrasonic waves, and the transducers 21 adjacent to each transducer 21. And a ultrasonic wave transmitting / receiving surface of the transducer 21 and a comparatively soft material filled between the transducers 21 so as not to cause so-called acoustic coupling that generates an unnecessary signal. The acoustic impedance of the living body and the acoustic impedance of the transducer 21 are matched to each other and the ultrasonic wave with a small wave number is attached to The matching layer 22 for efficiently injecting light into the living body, the acoustic lens 23 attached to the matching layer 22 for converging the ultrasonic waves, the transducer 21 and an ultrasonic wave transmitting / receiving circuit (not shown) electrically. It is composed of a lead wire 24 to be connected.

However, a plurality of, here two, transducers 21 are commonly connected to one lead wire 24, and perform ultrasonic wave transmission / reception operations as if they were one transducer. The reason for adopting this common connection method is as follows. First, in order to increase the frequency as described above, it is necessary to reduce the thickness t of the material of the transducer 21 due to the characteristics of the material. Further, when the width w of the transducer 21 becomes about the same as the thickness t, a vibration mode in the width direction is mixed in addition to the originally necessary thickness vibration, and it becomes impossible to obtain a good transmission / reception pulse. It is necessary to make it minute according to the height t. As described above, in order to realize a higher frequency of the ultrasonic probe and to obtain a good transmission / reception pulse, the transducer 21 included in the ultrasonic probe needs to have a fine shape. Required. In this way, if the transducers 21 are made fine and the number of the transducers is increased and the transducers are connected to the transducers, the wiring and the transducers become unnecessarily complicated. Therefore, the common connection method as described above is used. ing. Details of this common connection method are disclosed in Japanese Patent Laid-Open No. 52-49689.

There is a limit in increasing the frequency of the current ultrasonic probe. This corresponds to the limit of miniaturization of the shape of the transducer 21. The reason for limiting the miniaturization is the strength of the fine transducer 21 in the manufacturing process. The actual manufacturing process of the ultrasonic probe will be described below. First, the back load material 25 and one transducer flat plate having a thickness t capable of obtaining a desired high frequency ultrasonic wave are bonded to each other to form a two-layer plate including the back load material 25 and the transducer flat plate. Here, the back load member 25 is provided with a plurality of lead wires 24, here two transducers are commonly connected, at predetermined intervals. Then, the width w corresponding to the thickness t of the transducer flat plate
In order to obtain, a transducer flat plate is cut at intervals of a cutting pitch d to form a plurality of grooves. Here, as shown in FIG. 7, the depth of this cutting is a little larger than the thickness t of the transducer 21, and is a depth such that it slightly penetrates into the back load material 25. Next, this groove is filled with a low hardness filler, for example, low hardness silicon rubber. This filler is required to have low hardness so that acoustic coupling does not occur between the transducers adjacent to each other. Next, the matching layer 22 is mounted on the ultrasonic wave transmitting / receiving surface side of the transducer, that is, the upper surface side of the paper surface, and the acoustic lens 23 is mounted above the matching layer 22. An ultrasonic probe is obtained through such steps.

[0006]

As described above, in recent years, there has been a demand for high image quality and high resolution by high frequency ultrasonic waves. Therefore, increasing the frequency of the ultrasonic probe is an important technical theme. It has become to. In order to achieve a higher frequency of this ultrasonic probe, it is required to reduce the thickness and width of the transducer according to the wavelength. However, in the conventional ultrasonic probe, the thickness and width of the transducer are limited due to its manufacturing method and structure, that is, there is also a limitation in increasing the frequency. The reason for causing the limitation is as follows. When the width of the transducer is reduced, the strength of the transducer itself is reduced, and there is a high possibility that the transducer may break during cutting or peel off from the support base (back load material). Therefore, there has been a limit in increasing the frequency of the conventional ultrasonic probe. Then, the objective of this invention is providing the ultrasonic probe which implement | achieves high frequency.

[0007]

An ultrasonic probe according to the present invention comprises a plurality of transducers arranged on a support,
Between a means for common connection for each of a predetermined number of consecutive transducers of the plurality of transducers, a first filling material filled between each transducer group, and the predetermined number of transducers included in each transducer group A second filler having a hardness higher than that of the first filler to be filled is provided.

[0008]

According to the present invention, noting that some acoustic coupling is allowed for the transducers included in the transducer group, the first filling material filled between the transducer groups is provided between the transducers. By filling the second filling material having higher hardness, the transducer can be reinforced, and as a result, the width of the transducer can be reduced, and an ultrasonic probe capable of realizing high frequency can be obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment will be described below with reference to the drawings. Here, in the ultrasonic probe according to the present embodiment, two transducers are commonly connected to form one transducer group, and each transducer group is electrically separated and connected to an external ultrasonic transmission / reception circuit. The case where there is is explained. First, the structure of the ultrasonic probe according to the first embodiment will be described with reference to FIG. FIG. 1 is a perspective view showing the structure of an ultrasonic probe according to the first embodiment of the present invention.

The support 5 is a substrate of the entire ultrasonic probe, and is an acoustic load material for absorbing unnecessary ultrasonic waves other than the ultrasonic waves transmitted and received in a desired direction (above the paper surface). And a plurality of lead wires 4 for connecting two transducers in common are provided at predetermined intervals. A plurality of transducers 1 are arrayed on the support 5, and two transducers 1, that is, a transducer group, are commonly connected by a lead wire 4. The transducer 1 is made of piezoceramic and its thickness t is determined according to the desired ultrasonic frequency. Further, the width w of the transducer 1 is determined according to the thickness t. The ratio of the width w to the thickness t, that is, w / t, is required to be at least smaller than 1. For example, when the transducer 1 is made of lead zirconate titanate-based ceramic, this w / t is 0. It is desirable to set it to 55. This w / t has an optimum value according to the material of the transducer 1, and may be set according to the material. One transducer group, that is, two transducers 1 adjacent to each other is electrically connected in common to an ultrasonic transmission / reception circuit (not shown) by sharing one lead wire 4.

The first filling material 11 fills the space between the transducer groups (hereinafter referred to as "electrode groove"), and the second filling material 10 fills the space between the commonly connected transducers 1 (hereinafter referred to as "sub-die groove"). Called)). Here, the first filler 11 is made of a material having a low hardness that absorbs vibration so that acoustic coupling does not occur between the transducer groups adjacent to each other, usually a low hardness silicone rubber. The first filler 11 may be the same material as the conventionally used filler. It should be noted that some acoustic coupling may occur between the transducers 1 electrically connected to the second filler 10 in common, and the hardness is sufficiently higher than that of the first filler 11. A material such as high hardness silicon rubber is used.

The matching layer 2 is mounted on an ultrasonic wave transmitting / receiving surface (upper surface of the paper) on which a plurality of transducers 1 are arranged. Similar to the conventional matching layer, the matching layer 2 matches the acoustic impedance of the living body with the acoustic impedance of the transducer 1 so that an ultrasonic pulse with a small wave number is efficiently incident on the living body. The acoustic lens 3 is mounted on the matching layer 2 and converges the ultrasonic waves transmitted / received from the transducer 1 like the conventional acoustic lens. Next, a method of manufacturing the ultrasonic probe configured as described above will be described. Figure 2
5 to FIG. 5 are views for sequentially explaining the method of manufacturing the ultrasonic probe.

First, one transducer plate adhered on the support base 5 is sequentially cut at intervals of a cutting pitch 2d to obtain the state shown in FIG. 2 in which a plurality of sub die grooves 15 are provided. Normally, the depth of the sub-die groove 15 is such that it reaches the support base 5 to some extent as shown in FIG. Further, the cutting pitch 2d is set to a total value of twice the desired width w of the transducer 1, the width of the sub-die groove 15 and the width of the electrode groove 16 described later.

Then, each of the plurality of sub-die grooves 15 is filled with the second filling material 10, that is, high hardness silicone rubber, and after hardening, it is further cut so as to cut the center of each transducer formed by the first cutting. A plurality of electrode grooves 16 are obtained by sequentially cutting at a pitch of 2d (FIG. 3). Thus, by filling the sub-die groove 15 with the second filling material 10 having high hardness after the sub-die groove 15 is cut and before the electrode groove 16 is cut, the transducer plate before the sub-die groove 15 is cut Can have almost the same strength.

Further, each of the plurality of electrode grooves 16 is filled with the first filling material 11, that is, low hardness silicon rubber (FIG. 4). Finally, as shown in FIG. 5, the matching layer 2 and the acoustic lens 3 are attached, and the ultrasonic probe according to the present embodiment can be obtained. Here, the matching layer 2 may be obtained by coating a matching material, or may be obtained by mounting a film made of the matching material. The matching layer 2 may be a single layer or a multi-layer.

By adopting the above-described structure and manufacturing method, it is possible to obtain an ultrasonic probe which can realize a higher frequency than the conventional ultrasonic probe. That is, by dividing the cutting process of the transducer plate when manufacturing the ultrasonic probe into two processes, the cutting pitch in one cutting process is about 2 times that of the conventional cutting pitch.
The transducer at the time of fabrication is doubled by filling the sub-die groove obtained by the previous cutting step after the previous cutting step in the two cutting steps and before the subsequent cutting step with the filler having relatively high hardness. The strength of can be improved. As a result, it is possible to obtain a finer transducer than the transducer of the conventional ultrasonic probe, and it is possible to manufacture a high-performance high-frequency ultrasonic probe with high yield.

Here, the second filling material filling the sub-die groove and the first filling material filling the electrode groove have the same hardness only in the following cases, that is, the first filling material conventionally used.
It may be a filler. That is, even if the sub-die groove obtained in the cutting step preceding the cutting step 2 is filled with the second filling material, that is, low-hardness silicon rubber, sufficient strength of each transducer can be maintained, that is, peeling or breakage. When the sub-die groove does not occur
The filler may be used. Next, a second embodiment will be described.

FIG. 6 is a sectional view showing the structure of the ultrasonic probe according to this embodiment. Similarly to the ultrasonic probe according to the first embodiment, the ultrasonic probe according to the present embodiment also includes two transducers as one transducer group, which are electrically separated for each transducer group, so It shall be connected to a sound wave transmitting / receiving circuit.

In FIG. 6, parts corresponding to those in FIG.
Although the same reference numerals are given and detailed description is omitted, as can be seen from the reference numerals given in FIG. 1 and FIG. 6, there are no reference numerals other than those given in FIG. That is, the constituent elements of the ultrasonic probe according to the present embodiment are the same as those of the ultrasonic probe according to the first embodiment, and the ultrasonic probe according to the present embodiment relates to the first embodiment. It is structurally different from the ultrasonic probe.

The structural difference between the ultrasonic probe according to this embodiment and the ultrasonic probe according to the first embodiment is that the upper end of the first filling material 11 filled in the electrode groove is aligned. That is, it penetrates the layer 2. This structural difference occurs due to the difference in the manufacturing process. The manufacturing process of the ultrasonic probe according to this embodiment will be described below in order of process.

First, one transducer plate adhered on the support 5 is cut with a cutting pitch 2d as in the previous embodiment.
A plurality of sub die grooves are obtained by sequentially cutting at intervals of. Then, each of the sub-die grooves is filled with the second filling material 10. After filling and hardening the second filling material 10, the matching layer 2 is attached to the ultrasonic wave transmitting / receiving surface side of this transducer before cutting to obtain the electrode groove. This matching layer 2
May be obtained by coating as in the case of the first embodiment, may be obtained by mounting a film, or may be a multilayer matching layer 2. Next, the layer plate provided with the matching layer 2 is sequentially cut at intervals of a cutting pitch 2d so as to form electrode grooves. This cutting is performed from the matching layer 2 through the transducer layer to the support base layer. Each of the electrode grooves is filled with the first filling material 11, that is, low hardness silicon rubber. Thereafter, a matching layer may be further mounted on the cut matching layer 2 if necessary. Finally, the acoustic lens 3 is mounted on the matching layer 2 to obtain an ultrasonic probe.

In this way, the matching layer 2 is formed into the second sub-die groove.
The transducer of the first embodiment can be further improved in strength by mounting the same after filling with the filling material 10 of FIG. It is possible to obtain a finer transducer than the transducer of the ultrasonic probe according to the above, and it is possible to manufacture a high-performance high-frequency ultrasonic probe with high yield. A transducer 1 in which a first filler 11 having a high vibration absorption rate is commonly connected
By protruding toward the living body side, it is possible to suppress unnecessary ultrasonic waves generated by diffuse reflection inside the living body from entering the transducer 1.

The present invention is not limited to the above embodiment. For example, as described above, the matching layer may be obtained by coating a matching material, may be obtained by mounting a film made of the matching material, and the matching layer may be one layer or multiple layers. Further, the number of transducers commonly connected is two in the above embodiment, but may be three or more. The lead wire for commonly connecting a plurality of transducers and electrically connecting to an external ultrasonic wave transmitting / receiving circuit may be any means for electrically connecting, for example, an electrode layer provided in the support base. ..

[0024]

As described above, according to the present invention, it is noted that some acoustic coupling is allowed between the transducers included in the transducer group,
The transducer can be reinforced by filling the space between the transducers with the second filling material having a hardness higher than that of the first filling material filled between the transducer groups, and as a result, the width of the transducer can be reduced. Therefore, it is possible to obtain an ultrasonic probe that can realize higher frequencies.

[Brief description of drawings]

FIG. 1 is a perspective view showing a structure of an ultrasonic probe according to a first embodiment.

FIG. 2 is a cross-sectional view showing the structure of the ultrasonic probe at the first step in the manufacturing process of the ultrasonic probe shown in FIG.

FIG. 3 is a cross-sectional view showing the structure of the ultrasonic probe at the second step in the manufacturing process of the ultrasonic probe shown in FIG.

FIG. 4 is a cross-sectional view showing the structure of the ultrasonic probe at the third step in the manufacturing process of the ultrasonic probe shown in FIG.

5 is a cross-sectional view showing the structure of a completed ultrasonic probe after the fourth step in the manufacturing process of the ultrasonic probe shown in FIG. 1 is completed.

FIG. 6 is a perspective view showing the structure of an ultrasonic probe according to a second embodiment.

FIG. 7 is a perspective view showing the structure of a conventional ultrasonic probe.

[Explanation of symbols]

1 ... Transducer, 2 ... Matching layer, 3 ... Acoustic lens,
4 ... Lead wire, 5 ... Support base, 10 ... First filling material, 11
… Second filler.

Claims (1)

Claim: What is claimed is: 1. A plurality of transducers arranged on a support base, a means for commonly connecting a predetermined number of consecutive transducers of the plurality of transducers, and between each transducer group. An ultrasonic wave, comprising: a first filling material to be filled; and a second filling material having a hardness higher than that of the first filling material filled between the predetermined number of transducers included in each transducer group. Probe.