JP3313637B2 - 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 for use in an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic probe for improving the mechanical strength of a piezoelectric vibrator and preventing the penetration of chemicals.

[0002]

2. Description of the Related Art A general structure of a conventional electronic scanning ultrasonic probe used in an ultrasonic diagnostic apparatus is shown in FIG.
This will be described with reference to FIG. In FIG. 6, the piezoelectric vibrator 11 is
A vibrator made of piezoelectric ceramics for transmitting and receiving ultrasonic waves. The first acoustic matching layer 12 is a matching layer for efficiently transmitting ultrasonic waves. The second acoustic matching layer 13 is also a matching layer for efficiently transmitting ultrasonic waves. The acoustic lens 14 is a lens for converging an ultrasonic wave. The back load 15 is a load material for absorbing and attenuating the ultrasonic waves emitted from the back of the piezoelectric vibrator 11.
Piezoelectric vibrator 11, first acoustic matching layer 12, and second acoustic matching layer 13
Thus, the piezoelectric vibrating elements 11a, 11b, 11c... 11n are constituted.

[0003] Among electronic scanning ultrasonic probes, in particular,
In the case of the electronic sector scanning type ultrasonic probe, the ultrasonic beam is scanned in a sector shape by electronic control, so that the first acoustic matching layer 12, the second acoustic matching layer 13, the piezoelectric vibrator
11 is completely divided, and the division groove is deeply cut into the back load 15. The divided piezoelectric vibration elements 11a, 11b,
Fillers 17 (for example, a silicone resin having a small hardness) for suppressing acoustic crosstalk between the piezoelectric vibrating elements are filled in the divided grooves between 11c... 11n, and the individual piezoelectric vibrating elements 11a and 11b are filled. , 11c... 11n are made to have a wide directivity.

[0004]

In such a structure of the electronic scanning ultrasonic probe, the first acoustic matching layer 12, the second acoustic matching layer 13, and the piezoelectric vibrator 11 are completely divided. In addition, structurally, there is a problem that the mechanical strength of each piezoelectric vibration element against external stress and impact is weak.

In a conventional ultrasonic probe having such a structure, components such as an acoustic lens, a plurality of acoustic matching layers, a piezoelectric vibrator, and a back load are not shown in the drawings. It is bonded and integrated with an adhesive such as a system resin or a silicone resin. For example, an acoustic lens
Silicone resin is used to bond the second acoustic matching layer 14 to the first acoustic matching layer 13. The first acoustic matching layer 12 and the second acoustic matching layer 13, the piezoelectric vibrator 11 and the first acoustic matching layer 12, the back load 15 and the piezoelectric Vibrator 11
An epoxy resin adhesive is used for each bonding. In an ultrasonic probe in which each component is integrated with such an adhesive, a sterilizing solvent of a chemical passes through the acoustic lens 14 during use, and the sterilizing solvent further bonds the components inside the acoustic lens 14 to each other. There is a problem in that the adhesive layer wraps around the layer and causes damage such as a decrease in adhesive strength and peeling. Generally, the acoustic lens 14 made of silicone is highly permeable to chemicals used in the disinfecting solution (eg, alcohol, sidedex, hibiten, etc.), so that the chemicals penetrate and each adhesive in the acoustic lens 14 Penetrates the layer and adversely affects it, reducing adhesion.

The present invention solves the above-mentioned problems and improves the mechanical strength of each piezoelectric vibration element against external stress and impact without deteriorating the performance of the piezoelectric vibration element of the ultrasonic probe. It is an object of the present invention to provide an excellent ultrasonic probe capable of preventing a component or an adhesive layer from being adversely affected by a chemical or a solvent.

[0007]

In order to achieve the above object, according to the present invention, an ultrasonic probe includes a surface of an acoustic matching layer in contact with an acoustic lens, an inside of a dividing groove, and a back load. A thin reinforcing layer made of a material (for example, polyparaxylylene) that has high hardness, low permeability to chemicals and solvents, and does not adversely affect the performance of the ultrasonic probe, It was configured to be formed.

By configuring the ultrasonic probe in this manner, the mechanical strength of the piezoelectric vibrator against external stress and impact is improved, and the adverse effect on the adhesive layer of each component due to chemicals or solvents. Can be prevented.

From the characteristics of various polymers and the chemical structural formula of polyparaxylylene shown in FIG. 5, it can be easily inferred that polyparaxylylene has low permeability to general gases and water vapor. .

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION
A piezoelectric vibrator for transmitting and receiving ultrasonic waves, one or more acoustic matching layers bonded to the piezoelectric vibrator for efficiently transmitting ultrasonic waves, and a back surface of the piezoelectric vibrator for suppressing reverberation. Back load, comprising an acoustic lens adhered to the acoustic matching layer to converge ultrasonic waves,
An electronic scanning ultrasonic probe comprising an ultrasonic transducer divided in the scanning direction by a dividing groove in which the piezoelectric vibrator and all the acoustic matching layers are cut to the back surface load,
A reinforcing layer is provided continuously on the entire surface of the acoustic matching layer in contact with the acoustic lens, the inside of the dividing groove, and the entire ultrasonic transducer including the back load, and the reinforcing layer provided inside the dividing groove is provided. This is an ultrasonic probe provided with a filler thereon, and has an effect of increasing mechanical strength by a reinforcing layer and preventing invasion of chemicals.

The invention according to claim 2 of the present invention is the invention according to claim 1.
In the ultrasonic probe described, the thickness of the reinforcing layer is 0.5
The ultrasonic probe is in the range of μm to 20 μm.
This has the effect of increasing the mechanical strength of the reinforcing layer without deteriorating the performance and preventing the invasion of chemicals.

[0012]

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described in detail with reference to FIG.

(First Embodiment) A first embodiment of the present invention relates to an ultrasonic probe having a structure in which a piezoelectric vibrating element is cut to the back load, and an acoustic lens of each piezoelectric vibrating element. An ultrasonic probe in which a polyparaxylylene reinforcing layer is provided on the entire surface of the ultrasonic matching element including the surface of the acoustic matching layer, the inside of the dividing groove, and the back load, which is in contact with the acoustic matching layer.

FIG. 1 is a sectional view of an ultrasonic probe according to a first embodiment of the present invention. An electronic scanning ultrasonic probe in which a plurality of piezoelectric vibrating elements are arranged. In particular, the piezoelectric vibrator and all acoustic matching layers are divided in the scanning direction, and the dividing grooves are cut to the back load. It has a mixed structure. In FIG. 1, a piezoelectric vibrator 1 is a vibrator made of a piezoelectric ceramic or the like for transmitting and receiving ultrasonic waves. The first acoustic matching layer 2 is a matching layer for efficiently transmitting ultrasonic waves. The second acoustic matching layer 3 is a matching layer for efficiently transmitting ultrasonic waves by using a material having lower acoustic impedance than the first acoustic matching layer 2. The acoustic lens 4 is a lens for converging an ultrasonic wave. The back load 5 is for applying acoustic braking to the transmission signal and the reception signal from the piezoelectric vibrator 1 and for absorbing and attenuating the ultrasonic wave propagating from the back surface of the piezoelectric vibrator 1. Here, the piezoelectric vibration elements 1a, 1b, 1c
A set of 1n is called an ultrasonic transducer, and a device in which the ultrasonic transducer and the acoustic lens 4 are integrated is called an ultrasonic probe.

Referring to FIG. 1, the configuration of the ultrasonic probe according to the first embodiment will be described. Since the electronic sector scanning ultrasonic probe needs to largely deflect the ultrasonic beam, the first acoustic matching layer 2, the second acoustic matching layer 3, and the piezoelectric vibrator 1 are completely cut off, and the back load 5 It has a structure that is cut down. By adopting such a structure, acoustic crosstalk between the adjacent piezoelectric vibrating elements 1a, 1b, 1c... 1n becomes small, and the directivity of the emitted ultrasonic beam is wide. Thus, the ultrasonic beam can be deflected by the timing control of the electric signal applied to the piezoelectric vibrating elements 1a, 1b, 1c... 1n.

In the ultrasonic probe having such a structure,
The surface of the second acoustic matching layer 3 in contact with the acoustic lens 4 of each of the piezoelectric vibrating elements 1a, 1b, 1c... 1n, the inside of the dividing groove, and the entire ultrasonic transducer including the back load 5 is made of polyparaxylylene. Is provided. Fillers 7 (for example, silicone resin) are filled on the reinforcing layer 6 in the grooves between the piezoelectric vibrating elements. Polyparaxylylene reinforcing layer 6
Is formed by, for example, polychloroparaxylylene (Parylene C: trade name of Union Carbide, USA), which is a product obtained by polymerization of polyparaxylylene, or polydechloroparaxylylene (Parylene D, Union Car USA) The composition can be coated by chemical vapor deposition (CVD). In this way, the mechanical strength of the piezoelectric vibrating elements 1a, 1b, 1c... 1n against external stress and impact can be improved by the polyparaxylylene reinforcing layer 6.

Furthermore, the polyparaxylylene reinforcing layer 6 prevents the permeation of the sterilizing solvent from the acoustic lens 4 from penetrating.
In each of the piezoelectric vibrating elements 1a, 1b, 1c.
A sterilizing solvent for the epoxy resin of the adhesive layer between the acoustic matching layer 2 and the second acoustic matching layer 3, between the piezoelectric vibrator 1 and the first acoustic matching layer 2, and between the back load 5 and the piezoelectric vibrator 1. Can be prevented.

FIG. 4 is a graph showing the change in weight when the silicone material as the material of the acoustic lens 4 is immersed in ethanol with respect to the thickness of the polychloroparaxylylene layer. As is clear from the measurement results in FIG. 4, it was confirmed that the weight change rate was reduced by a factor of 4 with respect to ethanol in the thin film coating having a polychloroparaxylylene layer thickness of 4 μm. The effect of preventing was confirmed.

From this, if the reinforcing layer 6 is constituted by a thin layer in the range of 0.5 μm to 20 μm which is sufficiently shorter than the wavelength in the frequency range (1 MHz to 20 MHz) of the ultrasonic wave usually used in the ultrasonic diagnostic apparatus, The above effects can be obtained without adversely affecting the performance of the ultrasonic probe. Also, the groove width for dividing the piezoelectric vibrating element is generally 20 μm to 60 μm.
m, and the thickness of the reinforcing layer is in the range of 0.5 μm to 20 μm.
It is possible to provide a reinforcing layer 6 as shown in FIG.

As described above, in the first embodiment of the present invention, the ultrasonic probe is connected to the surface of the acoustic matching layer in contact with the acoustic lens of each piezoelectric vibrating element, the inside of the dividing groove, and the back surface. Since the reinforcing layer made of polyparaxylylene is provided on the entire ultrasonic transducer including the load, the mechanical strength of the piezoelectric vibrating element can be increased and the sterilizing solvent can be prevented from entering.

(Second Embodiment) A second embodiment of the present invention relates to an ultrasonic probe having a structure in which a piezoelectric vibrating element is cut to the back load, and an acoustic lens of each piezoelectric vibrating element. An ultrasonic probe in which a polyparaxylylene reinforcing layer is provided on the entire surface of the ultrasonic conversion element including the surface of the acoustic matching layer in contact with the acoustic lens, the surface of the filler in contact with the acoustic lens, and the back load.

FIG. 2 is a sectional view of an ultrasonic probe according to a second embodiment of the present invention. In FIG. 2, components having the same functions as those shown in FIG.
Detailed description is omitted. The basic structure of the ultrasonic probe according to the second embodiment is a structure in which the piezoelectric vibrating element and all acoustic matching layers are divided in the scanning direction, and the division grooves are cut to the back load. , And the same as the first embodiment.

Referring to FIG. 2, the configuration of the ultrasonic probe according to the second embodiment will be described. Each piezoelectric vibration element 1a, 1
b, 1c... 1n, the surface of the second acoustic matching layer 3 in contact with the acoustic lens 4, the surface of the filler 7 filled in the dividing groove,
A reinforcing layer 6 of polyparaxylylene is provided on the entire ultrasonic transducer including the back load 5.

By covering the whole element with the reinforcing layer 6, each piezoelectric vibrating element 1a, 1b, 1
In this case, the mechanical strength of c... 1n is improved, and a sterilizing solvent is prevented from entering each adhesive layer (not shown) so as not to damage the adhesive. Although not shown as an embodiment, the same effect can be obtained by combining the first embodiment and the second embodiment. It is clear from the description of the mode.

As described above, according to the second embodiment of the present invention, the ultrasonic probe is provided with a surface where the acoustic matching layer of each piezoelectric vibrating element is in contact with the acoustic lens and a surface of the filler which is in contact with the acoustic lens. In addition, since the reinforcing layer made of polyparaxylylene is provided on the entire ultrasonic conversion element including the back load, the mechanical strength of the piezoelectric vibrating element can be increased, and the intrusion of the sterilizing solvent can be prevented.

(Third Embodiment) A third embodiment of the present invention relates to an ultrasonic probe having a structure in which a piezoelectric vibrating element is cut down to the back load, and a polyparaxylinder is provided on an inner surface of an acoustic lens. It is an ultrasonic probe provided with a reinforcement layer of ren.

FIG. 3 is a sectional view of an ultrasonic probe according to a third embodiment of the present invention. In FIG. 3, FIG. 1 and FIG.
Those having the same functions as those shown in (1) are denoted by the same reference numerals, and detailed description thereof will be omitted. The basic structure of the ultrasonic probe according to the third embodiment is the same as that described in the first and second embodiments.

Referring to FIG. 3, the configuration of the ultrasonic probe according to the third embodiment will be described. The reinforcing layer 6 is provided on the inner surface of the acoustic lens 4, that is, the surface in contact with the second acoustic matching layer 3 and the surface in contact with the filler 7. As in the second embodiment, the reinforcing layer 6 provided on the inner surface of the acoustic lens 4
, The mechanical shock to the piezoelectric vibrating elements 1a, 1b, 1c... 1n can be reduced, and the sterilizing solvent is prevented from entering each adhesive layer (not shown), and the adhesive is damaged. It is possible not to.
Note that providing the reinforcing layer 6 on the surface of the acoustic lens 4
It is not suitable because the reinforcing layer may wear out during use and impair the effect.

As described above, in the third embodiment of the present invention, the ultrasonic probe has a structure in which the reinforcing layer of polyparaxylylene is provided on the inner surface of the acoustic lens. It is possible to increase the mechanical strength and prevent the intrusion of the sterilizing solvent.

[0031]

As described above, according to the present invention, the electronic scanning ultrasonic wave has a structure in which the piezoelectric vibrator and all the acoustic matching layers are divided in the scanning direction, and the dividing grooves are cut to the back load. The probe is provided with a reinforcing layer such as polyparaxylylene, which relieves external shocks and mechanical shocks such as shocks applied to the divided ultrasonic vibrating element, as well as the acoustic matching layer and the piezoelectric vibrator. An effect is obtained in which a sterilizing solvent or the like is prevented from permeating and penetrating from the acoustic lens into the adhesive layer, and an excellent ultrasonic probe with high performance, quality and reliability can be realized.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of an ultrasonic probe according to a second embodiment of the present invention;

FIG. 3 is a cross-sectional view of an ultrasonic probe according to a third embodiment of the present invention;

FIG. 4 shows measurement data showing the effect of a polychloroparaxylylene layer on a solvent,

FIG. 5 is a table showing gas and water vapor permeability data of each polymer;

FIG. 6 is a cross-sectional view of a conventional ultrasonic probe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric vibrator 2 1st acoustic matching layer 3 2nd acoustic matching layer 4 Acoustic lens 5 Back load 6 Reinforcement layer 7 Filler 1a, 1b, 1c ... 1n Piezoelectric vibrating element

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-25500 (JP, A) JP-A-2-200099 (JP, A) JP-A-5-244689 (JP, A) JP-A-5-205 37998 (JP, A) JP-A-5-228142 (JP, A) JP-A-7-308317 (JP, A) JP-A-8-612 (JP, A) Japanese Utility Model Application Sho-61-40658 (JP, U) Japanese Utility Model Application Hei 4-102398 (JP, U) Japanese Utility Model Application Hei 6-58916 (JP, U) Japanese Utility Model Application Hei 7-308 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) A61B 8/00 G01N 29/00 H04R 17/00

Claims (2)

(57) [Claims] 1. A piezoelectric vibrator for transmitting and receiving ultrasonic waves, one or more acoustic matching layers bonded to the piezoelectric vibrator for efficiently transmitting ultrasonic waves, and the piezoelectric vibrator for suppressing reverberation And a acoustic lens adhered to the acoustic matching layer to converge ultrasonic waves, wherein the piezoelectric vibrator and all the acoustic matching layers are cut into the back load. In the electronic scanning ultrasonic probe including the ultrasonic transducers divided in the scanning direction by the divided groove, the surface includes the surface of the acoustic matching layer in contact with the acoustic lens, the inside of the division groove, and the back surface load. An ultrasonic probe, wherein a continuous reinforcing layer is provided on the entire ultrasonic conversion element, and a filler is provided on the reinforcing layer provided inside the division groove. 2. The reinforcing layer has a thickness of 0.5 μm to 20 μm.
2. The ultrasonic probe according to claim 1, wherein
Tentacles.