JP3314121B2 - Ultrasonic probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe used in the fields of diagnosis and measurement of living bodies and objects using ultrasonic waves.

[0002]

2. Description of the Related Art As shown in FIG. 10, a transducer portion of an ultrasonic probe used in an ultrasonic diagnostic apparatus or the like has a structure as shown in FIG.
On the back surface of a piezoelectric vibrator 2 such as PZT or PbTiO ₃ having electrodes formed on both sides, it is formed of a resin or the like having a high ultrasonic attenuation rate for the purpose of absorbing unnecessary ultrasonic waves emitted to the back side. The back load member 6 is provided. A matching layer 3 is provided on the surface of the piezoelectric vibrator 2 for acoustic matching with the subject. Reference numerals 4 and 5 are electrode leads and signal leads.

In Japanese Patent Application Laid-Open No. 63-73942, an ultrasonic absorber is used as a backing material, and a saw-like portion is provided on the back surface, and the height of the sawing portion is the wavelength (2n-1) in the backing material.
/ 4. However, in this disclosure, a material having a high ultrasonic wave absorption rate is used as the back material, and further, the first and second back materials are provided on the back of the vibrator, and the thickness of the back material is sufficient. The thickness is such that the ultrasonic waves can be absorbed.

[0004]

However, in the ultrasonic probe having the above-described structure, the back load material sufficiently obtains the effect of attenuating the ultrasonic wave emitted to the back surface by absorption. Therefore, it was necessary to make the back load material sufficiently thick. This makes it difficult to reduce the size of the ultrasonic probe. In particular, in the case of a small probe such as an intracavity probe, the thickness of the back load material cannot be made sufficiently large, and the ultrasonic probe is released to the back. The absorption of the ultrasonic waves
Reflection from the back surface causes image quality degradation and the like. In addition, a portion where electrode deposition is not performed is provided on the front surface side of the vibrator, and signal electrode leads are taken from a portion of the back side of the non-deposited portion which does not contribute to ultrasonic vibration, so that the vibrator is not used. Effective aperture is smaller than the actual area of the vibrator, and in the case of a matrix array type probe composed of many microvibrators, it is possible to form a portion that does not contribute to vibration in each vibrator. In addition, it is difficult to mount wiring and the like, and deterioration of image quality is inevitable.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the back load material and the electrode lead, and to provide an ultrasonic probe which is easy to mount and has excellent image quality.

[0006]

What achieves the above object is an ultrasonic probe having an ultrasonic vibrator, wherein a lead portion of an electrode is provided on the back side of the ultrasonic vibrator, At least a part of the lead portion is formed by combining at least two or more types of conductors having different acoustic characteristics substantially in parallel with the ultrasonic direction, and at least one of the boundary surfaces of the conductors has a phase difference. This is an ultrasonic probe serving as a reflection section.

[0007] At least one of the conductors is made of any one of a conductive non-metal having a large Young's modulus and / or a large bending strength such as a conductive resin, metal, or conductive carbon. .

In order to achieve the above object, there is provided an ultrasonic probe having an ultrasonic vibrator, wherein a lead portion of an electrode is provided on a back side of the ultrasonic vibrator, and at least one of the lead portions is provided. Some are configured by combining at least two or more types of conductors having different acoustic characteristics substantially in parallel with the ultrasonic direction, and at least one of the boundary surfaces of the conductors serves as a phase difference reflection portion. Ultrasound probe,
At least one of the conductors has two different acoustic characteristics.
Acoustic media composed of different types of metals are alternately arranged.

Further, the interval between the two types of acoustic media is
It is preferably about 0.01 to 10 mm in parallel with the ultrasonic transducer, more preferably a longitudinal wave, a transverse wave corresponding to the frequency used in each acoustic medium, or an ultrasonic wavelength such as vibration at a boundary surface. , Less than that.

[0010] The phase difference reflection section is intended to reflect the ultrasonic wave emitted from the vibrator to the back side in the direction of the vibrator, and has the following characteristics.

A single surface or a combination of a plurality of surfaces having a substantially flat surface or a curved surface substantially opposed to the vibrator. At least a part of the ultrasonic wave is reflected by the difference in acoustic characteristics between the front and rear media. When the ultrasonic wave reflected by the reflecting surface reaches the vibrator surface or the inside of the vibrator, the phase relationship between a part of the ultrasonic wave and the other surface is determined by the relationship between the vibrator surface and the reflecting surface. The reflection surface has a characteristic that the phase relation at the time of emission from the vibrator is different due to the characteristics of the medium or the material behind the reflection surface.

[0012] The term "substantially opposed" means that most of the reflected wave traveling from the portion toward the vibrator is considered only in the geometrical positional relation ignoring refraction, reflection, attenuation, interference and the like in the middle. In addition, the arrangement is such that it reaches the vibrator effective portion.

The conductive non-metal has a Young's modulus of preferably 5 × 10 ³ kgf / mm ² or more, more preferably 15 × 10 ³ kgf / mm ² or more, and a bending strength of 10 kgf / mm 2. ^It is preferably ² or more, more preferably 15 kgf / mm ² or more.

Further, each of the two or more types of conductors has a concave portion and a convex portion each having a substantially rectangular cross section on one surface, and the concave portion of the first conductor and the concave portion of the second conductor have different shapes. It is preferable that the projections and the projections are fitted to each other.

The depth of the concave portion and the convex portion is 0.005.
It is preferably about 5 mm, more preferably about the length of an ultrasonic wavelength such as a longitudinal wave, a transverse wave, or vibration at a boundary surface corresponding to the frequency used inside each conductor, or a length less than that, and a width. Is preferably about 0.005 to 5 mm, and more preferably the length of an ultrasonic wavelength such as a longitudinal wave, a transverse wave, or vibration at a boundary surface corresponding to the frequency used inside each conductor, or a length less than that. Degree, the interval is 0.01 ~
It is preferably about 10 mm, more preferably, about the length of an ultrasonic wavelength such as a longitudinal wave, a transverse wave, or vibration at a boundary surface corresponding to the operating frequency inside each conductor, or a length about the same. Is formed.

Further, the thickness of the conductor is 0.01 to 10
mm, more preferably, the length of an ultrasonic wavelength such as a longitudinal wave, a transverse wave or vibration at a boundary surface corresponding to the frequency used inside each conductor, or a length less than that, and the width is , Preferably about 0.1 to 10 mm, more preferably a longitudinal wave corresponding to the frequency used inside each conductor,
The degree of the ultrasonic wavelength, such as a shear wave or vibration at the boundary,
It is about the length less than that, the length is 0.2-20 mm
The degree is preferred.

Further, when a conductive resin is used for the conductor, the conductive material is composed of an epoxy resin mixed with metal particles, a silicone resin mixed with metal particles, or the like. , Cu, Ni, A
g, Pt, Au and their alloys, etc.,
When a conductive non-metal is used, conductive carbon,
The best combination is made of conductive ceramics such as TiN. The best combination is made of Ag as the first conductor and metal particles mixed with silicone resin as the second conductor, or carbon, ceramic and resin. Combinations are preferred.

Further, it is possible to observe a wide area such as the abdomen,
Conversely, when the resolution is improved by focusing, the ultrasonic probes are preferably arranged in an array type, a matrix array type, or the like.

Further, it is preferable that the ultrasonic probe has a shape curved in the array direction.

[0020]

According to the ultrasonic probe of the present invention, as in the conventional case, a portion which does not contribute to vibration is formed on the back surface of the vibrator to take a lead. The electrode lead on the back side of the transducer is provided with a lead part of the electrode on the back side of the ultrasonic transducer, and at least a part of the lead part has at least two types of conductors having different acoustic characteristics in the ultrasonic direction. It is composed by combining in parallel with
At least one of the boundary surfaces of the conductor is a phase difference reflecting portion, so that the ultrasonic wave is positively reflected while being shifted in phase, and the phase difference between the reflected waves is used to form an electrode. It is possible to reduce the influence of the reflected wave from the lead and the structural member behind the lead.

As described above, the electrode leads themselves are:
Since it has a role of a back load material to reduce the influence of unnecessary ultrasonic waves emitted to the back of the transducer, there is no need to provide a back load material, and the probe can be downsized.

Further, even for a probe such as a matrix array type probe, for which it is difficult to pull out the lead, the lead can be pulled out from the entire back surface of the transducer without concern for the influence of the reflected wave. , To facilitate the implementation.

[0023]

【Example】

(Embodiment 1) FIG. 1 is a perspective view showing a first embodiment of an ultrasonic probe according to the present invention. FIG. 2 is a perspective view showing an embodiment of the conductor of the ultrasonic probe according to the present invention.

As shown in FIG. 1, the ultrasonic probe 1 has a substantially planar shape and has electrodes (not shown) formed on both sides by vapor deposition.
An ultrasonic transducer 2 made of a piezoelectric material such as ZT, a matching layer 3 provided on the surface side of the ultrasonic transducer 2, and an electrode on the surface of the ultrasonic transducer 2 are electrically connected. It comprises a ground lead 4, a signal lead 5, a plurality of conductors constituting an electrode lead, and a back load member 6 located on the back side of the ultrasonic transducer.

The conductor is composed of a first signal electrode lead 7 provided at a position closest to the ultrasonic transducer 2 and a second signal electrode provided in contact with the back surface of the first electrode lead. And a lead 70.

The first signal electrode lead 7 is conductively connected to the electrode of the ultrasonic transducer 2 by soldering or the like, or is formed directly on the electrode of the ultrasonic transducer 2 by a method such as electroforming. The concave portion 8 and the convex portion 80 are formed on the back side as shown in FIG.

The second signal electrode lead 70 has a concave portion 8 and a convex portion 80 formed on the surface side, and the concave portion 8 of the first signal electrode lead and the convex portion 80 of the second signal electrode lead are fitted. And are conductively connected.

The first signal electrode lead 7 is made of a metal material, and the second signal electrode lead 70 is made of a material such as a conductive resin having a lower specific acoustic impedance than the first signal electrode lead 7. , A phase difference reflection surface is formed at the boundary surface between the first signal electrode lead 7 and the second signal electrode lead 70, and the phase difference reflection surface is formed between the first signal electrode lead 7 and the signal lead 5. Has the function of conductively adhering them.

(Embodiment 2) FIG. 3 is a perspective view showing a second embodiment of the ultrasonic probe according to the present invention.

As shown in FIG. 3, the ultrasonic probe 1 has a substantially planar shape, and has electrodes (not shown) formed on both sides by vapor deposition.
An ultrasonic transducer 2 made of a piezoelectric material such as ZT, a matching layer 3 provided on the surface side of the ultrasonic transducer 2, and an electrode on the surface of the ultrasonic transducer 2 are electrically connected. It is composed of a ground lead 4, a signal lead 5, and a plurality of conductors constituting an electrode lead.

The other configuration is as described in (Embodiment 1), except that the ultrasonic probe 1 can be easily downsized because the back load member 6 is not required.

(Embodiment 3) FIG. 4 is a perspective view showing an ultrasonic probe according to a third embodiment of the present invention. FIG. 5 is a plan view showing a circuit board of the ultrasonic probe according to the present invention. FIG.
FIG. 6 is a perspective view (curved shape) showing a third embodiment of the ultrasonic probe of the present invention.

As shown in FIG. 4, the ultrasonic probe 1 has a substantially planar shape, and has electrodes (not shown) formed on both sides by vapor deposition.
An ultrasonic transducer 2 made of a piezoelectric material such as ZT, a matching layer 3 provided on the surface side of the ultrasonic transducer 2, and an electrode on the surface of the ultrasonic transducer 2 are electrically connected. The ultrasonic probe 1 is composed of a ground lead 4 and a plurality of conductors constituting an electrode lead. The ultrasonic probes 1 are arranged in an array, and are electrically connected to the conductors of the respective ultrasonic probes 1. The circuit board 9 is provided.

As shown in FIG. 5, on the circuit board 9, a conductor pattern 90 corresponding to each element is formed, a portion 91 where a conductor is exposed is formed in a part of the conductor pattern, and the other portions are short-circuited. Is coated to prevent.

The other structure is as described in the first embodiment.

As shown in FIG. 6, the ultrasonic probe 1
Are curved in the array direction. This allows
It is useful for observing a wide area such as the abdomen.

(Embodiment 4) FIG. 7 is a perspective view showing an ultrasonic probe according to a fourth embodiment of the present invention. FIG. 8 is a plan view showing a circuit board of the ultrasonic probe according to the present invention.

As shown in FIG. 7, the ultrasonic probe 1 has a substantially planar shape, and is formed by depositing electrodes (not shown) on both surfaces by vapor deposition.
The ultrasonic transducer 2 is composed of an ultrasonic vibrator 2 made of a piezoelectric material such as ZT, a matching layer 3 provided on the surface side of the ultrasonic vibrator 2, and a plurality of conductors forming electrode leads. The probes 1 are arranged in a matrix array type, and have a circuit board 9 electrically connected to the conductor of each ultrasonic probe 1.

As shown in FIG. 8, on the circuit board 9, a conductor pattern 90 corresponding to each element is formed, a portion 91 where a conductor is exposed is formed in a part of the conductor pattern, and the other portions are short-circuited. Is coated to prevent.

Other configurations are as described in (Embodiment 1), and this embodiment can also be arranged in a curved shape.

(Embodiment 5) FIG. 9 is a perspective view showing an embodiment of an ultrasonic probe according to the present invention.

As shown in FIG. 9, the ultrasonic probe 1 has a substantially planar shape, and has electrodes (not shown) formed on both sides by vapor deposition.
An ultrasonic transducer 2 made of a piezoelectric material such as ZT, a matching layer 3 provided on the surface side of the ultrasonic transducer 2, and an electrode on the surface of the ultrasonic transducer 2 are electrically connected. The ultrasonic probe 1 is composed of a ground lead 4 and a plurality of conductors constituting an electrode lead. The ultrasonic probes 1 are arranged in an array and electrically connected to the conductors of the respective ultrasonic probes 1. The circuit board 9 is provided.

The conductor is composed of a first signal electrode lead 7 and a second signal electrode lead 70. The first signal electrode lead 7 has two kinds of metals having different acoustic characteristics alternately arranged. The second signal electrode lead 70 is formed of a material such as a conductive resin.

In the above-described embodiment, only the case of a ceramic piezoelectric body is shown. However, the present invention is not limited to this embodiment, and a polymer piezoelectric material such as polyvinylidene fluoride, PZT or the like is added. Polymer composite materials such as polyvinylidene fluoride are also effective.

[0045]

As described above, the ultrasonic probe of the present invention is an ultrasonic probe having an ultrasonic vibrator,
An electrode lead portion is provided on the back side of the ultrasonic transducer,
At least a part of the lead portion is configured by combining at least two or more types of conductors having different acoustic characteristics substantially in parallel with the ultrasonic wave direction, and at least one of the boundary surfaces of the conductors has phase difference reflection. As a result, the effect of the reflected wave from the electrode lead or the like can be reduced without reducing the effective aperture of the ultrasonic transducer, and the mounting becomes easy.

Further, since at least one of the conductors is made of a conductive resin, it is easy to form and mount a phase reflector having a complicated shape.

Further, since at least one of the conductors is made of a metal, electric signals can be transmitted and received efficiently, and the intrinsic acoustic impedance is very low as compared with a conductive resin or the like. Therefore, the phase reflection portion can be easily formed.

In addition, at least one of the conductors is a conductive non-metal having high Young's modulus and / or bending strength such as conductive carbon. , The complicated groove processing becomes easy.

[Brief description of the drawings]

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

FIG. 2 is a perspective view showing an embodiment of a conductor of the ultrasonic probe.

FIG. 3 is a perspective view showing a second embodiment of the ultrasonic probe according to the present invention.

FIG. 4 is a perspective view showing a third embodiment of the ultrasonic probe according to the present invention.

FIG. 5 is a plan view showing a circuit board of the ultrasonic probe according to the present invention.

FIG. 6 is a perspective view (curved shape) showing a third embodiment of the ultrasonic probe of the present invention.

FIG. 7 is a perspective view showing a fourth embodiment of the ultrasonic probe according to the present invention.

FIG. 8 is a plan view showing a circuit board of the ultrasonic probe according to the present invention.

FIG. 9 is a perspective view showing one embodiment of the ultrasonic probe of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 ultrasonic probe 2 ultrasonic transducer 3 matching layer 4 ground lead 5 signal lead 6 back load material 7 first signal electrode lead 70 second signal electrode lead 8 concave portion 80 convex portion 9 circuit board 90 conductive pattern 91 Exposed conductor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H04R 17/00 330 A61B 8/00 G01N 29/24

Claims (5)

(57) [Claims] 1. An ultrasonic probe having an ultrasonic vibrator, wherein a lead portion of an electrode is provided on a back side of the ultrasonic vibrator,
At least a part of the lead portion is formed by combining at least two or more types of conductors having different acoustic characteristics substantially in parallel with the ultrasonic wave direction, and at least one of the boundary surfaces of the conductors has phase difference reflection. An ultrasonic probe characterized by being a part. 2. At least one of the conductors comprises:
The ultrasonic probe according to claim 1, wherein the ultrasonic probe is made of a conductive resin. 3. At least one of the conductors comprises:
The ultrasonic probe according to claim 1, wherein the ultrasonic probe is made of metal. 4. At least one of the conductors comprises:
The ultrasonic probe according to claim 1, wherein the ultrasonic probe is made of a conductive nonmetal and is selected from the group consisting of conductive carbon and conductive ceramic. 5. At least one of the conductors comprises:
The ultrasonic probe according to claim 1, wherein the probe is a conductive non-metal having high Young's modulus and / or bending strength.