JP2000139916A - Ultrasonic probe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic probe that can provide a piezoelectric transducer with a uniform matching layer having a desired thickness, with good yield, without interposing bubbles in a gap between the piezoelectric transducer. SOLUTION: A piezoelectric transducer 1 is provided with through holes 3, through holes 5 and through holes 13 corresponding to the through holes 3 are provided on a first matching layer 4 and a second matching layer 12, formed in thin plate shapes or film shapes with a desired thickness. In adhering and fixing the first and second matching layers 4, 12 and an acoustic lens 14 onto the acoustic radiation surface side of the piezoelectric transducer 1 via adhesives, excessive adhesive and bubbles between respective members are made to flow into the through holes 3, 5, 13, and therefore, the adhesive layers are formed thinner without forming an air layer between the respective members.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ultrasonic probe having at least one matching layer on the ultrasonic wave emitting side of a transducer.

[0002]

2. Description of the Related Art An ultrasonic probe used in an ultrasonic diagnostic apparatus such as an ultrasonic endoscope generally has a structure as shown in FIGS. That is, the ultrasonic probe has a piezoelectric vibrator 201, and a surface electrode 202 made of baked silver or the like is provided on both sides of the piezoelectric vibrator 201.
a and the back electrode 202b are formed.

[0003] A matching layer 203 and an acoustic lens 204 are provided on the acoustic emission surface side of the piezoelectric vibrator 201, while the backing layer 20 is provided on the back side of the piezoelectric vibrator 201.
5 are provided. Here, the backing layer 205
Is a housing 2 made of stainless steel via an insulating layer 207.
06.

The back electrode 202b is connected to the signal line 20.
8, connected to the inner conductor of the coaxial cable 211,
The electrode 202a is connected to a ground portion (external conductor) of the coaxial cable 211 from a cutout portion 209 provided in the matching layer 203 via a ground connection line 210 and a stainless steel housing 206. Further, the coaxial cable 211 is connected to a pulsar / receiver circuit (not shown) of the observation device.

[0005] In such an ultrasonic probe, the performance of the matching layer directly affects the performance.
It is important to provide a matching layer having a thickness of about one-half wavelength uniformly on the acoustic radiation surface of the piezoelectric vibrator.

[0006] In the ultrasonic probe, one or more matching layers are provided on the acoustic radiation surface,
It is also known to increase the sensitivity by broadening the frequency response of the probe. Specifically, when a piezoelectric ceramic such as lead zirconate is used as the piezoelectric vibration element, a thin glass plate can be provided as the first matching layer, and an epoxy resin can be provided as the second matching layer. When a composite piezoelectric body is used as the piezoelectric vibration element, an epoxy resin can be provided as the first matching layer.

[0007] As a method of providing such a matching layer on the acoustic radiation surface, conventionally, a method of obtaining a matching layer having a certain thickness by embossing a filler-containing resin or the like on the acoustic radiation surface of the piezoelectric vibrator has been known. Known methods include a method of adjusting the thickness by directly hardening the containing resin and the like on the acoustic emission surface of the piezoelectric vibrator and then polishing, and a method of laminating and bonding a thin plate or film having a desired thickness in advance with an epoxy adhesive or the like. I have.

[0008]

As described above, in the ultrasonic probe, in order to efficiently transmit and receive ultrasonic waves by transmitting and receiving ultrasonic waves in a wide band, a matching layer having a thickness in the vicinity of λ / 4 is required. Is preferably provided uniformly on the piezoelectric vibrator. In addition, it is important that there is no defect such as bubbles on the bonding surface between the piezoelectric vibrator and the matching layer.

However, the conventional matching layer forming method has the following problems.

First, in a method of embossing a filler-containing resin or the like onto the acoustic emission surface of a piezoelectric vibrator to obtain a matching layer having a constant thickness, it is difficult to control the thickness by curing shrinkage of the filler-containing resin or the like. there were.

Next, in the method of adjusting the thickness by directly hardening the filler-containing resin or the like on the acoustic radiation surface of the piezoelectric vibrator and then polishing, the operation requires skill, and the measurement or polishing of the thickness or impedance characteristics is required. I had to repeat.

Next, in the method of bonding a matching layer flat plate or film polished to a thickness of about λ / 4 to the piezoelectric vibrator surface with an adhesive, air enters between the vibrator surface and the matching layer surface, and the entire surface is formed. In this case, there is a problem that sufficient adhesiveness cannot be obtained over a long period of time, an excessive adhesive remains between the vibrator surface and the matching layer surface, and the thickness of the adhesive layer cannot be sufficiently reduced. In particular, when glass is used as the matching layer, if air is trapped between the piezoelectric vibrator and the matching layer, it is difficult to remove the trapped air, and it is also confirmed that no air is trapped. Because of the difficulty, it has been difficult to manufacture a high-performance ultrasonic probe with high yield.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an ultrasonic wave capable of providing a uniform matching layer with a desired thickness in a vibrator with high yield without intervening bubbles or the like between the vibrator and the vibrator. It is intended to provide a probe.

[0014]

In order to solve the above-mentioned problems, an ultrasonic probe according to the present invention comprises at least one film-like or thin-plate-like matching layer on an ultrasonic wave emitting side of an oscillator. In the ultrasonic probe laminated through
A plurality of through holes are provided in the matching layer.

That is, in the ultrasonic probe according to the present invention, when bonding the matching layer to the vibrator, excess adhesive is applied to the outer edge portion of the matching layer and the through-hole provided in the matching layer. Therefore, even when the vibrator is formed in a large area, the adhesive layer between the vibrator and the matching layer can be formed thin, and the vibrator can be formed at the time of lamination. Air bubbles trapped between the gap and the matching layer can be discharged to the outside through the through-hole, so that a probe with good transmission and reception ultrasonic waves can be easily formed with high yield.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 relate to a first embodiment of the present invention, FIG. 1 is a cross-sectional view showing a main part of an ultrasonic probe, FIG. 2 is an explanatory view showing a bonding step of a first matching layer, FIG. 3 is an exploded perspective view showing a part of components of the ultrasonic probe,
FIG. 4 is an explanatory view showing a process of bonding the second matching layer and the acoustic lens.

As shown in FIG. 1, the ultrasonic probe has a disk-shaped piezoelectric vibrator 1. A front surface electrode 2a and a back surface electrode 2b are formed on the entire surface of both surfaces of the piezoelectric vibrator 1, for example, by baking silver. Further, the piezoelectric vibrator 1 is provided with a plurality of through-holes 3 communicating the front side and the rear side of the piezoelectric vibrator 1. Here, the through-hole 3 is formed, for example, as a hole having a diameter of 0.4 mm.

On the surface electrode 2a side of the piezoelectric vibrator 1, there is provided a first matching layer 4 for broadening the frequency response of the probe and improving the sensitivity. The first matching layer 4 has a diameter slightly larger than the diameter of the piezoelectric vibrator 1 by grinding and polishing, and has a thickness of a quarter of the driving frequency of the piezoelectric vibrator 1. It is composed of a crystallized glass or ceramic thin plate member formed in
It is bonded to the surface electrode 2a by, for example, an epoxy adhesive.

The first matching layer 4 is provided with a through hole 5 at a position substantially corresponding to the through hole 3 of the piezoelectric vibrator 1. Here, the through hole 5 is formed as a hole having a smaller diameter than the through hole 3 provided in the piezoelectric vibrator 1.
For example, it is formed in a hole having a diameter of 0.2 mm.

A notch 6 is provided in a part of the outer periphery of the first matching layer 4, and a part of the surface electrode 2 a provided in the piezoelectric vibrator 1 is externally provided from the notch 6. Has been exposed.

The piezoelectric vibrator 1 and the first matching layer 4
Is held on the distal end side of a stainless steel housing 8 via a resin insulating frame 7.

That is, the insulating frame 7 has a step 9
Are formed on a cylindrical member provided with the piezoelectric element 1. The piezoelectric vibrator 1 is held on the inner periphery of the cylindrical portion, and the first matching layer 4 is held on the step portion 9. The housing 8 is formed in a cylindrical shape, and holds the insulating frame 7 on the inner periphery.

Here, the inner diameter of the cylindrical portion of the insulating frame 7 is formed to be about 1 mm larger than the outer diameter of the piezoelectric vibrator 1, and the inner diameter of the step portion 9 is the first alignment. It is formed to have a diameter slightly larger than the outer diameter of the layer 4 and a depth substantially equal to the thickness of the first matching layer 4 so as not to deteriorate the positioning accuracy of each member held therein. With good insertability. And the piezoelectric vibrator 1
And the first matching layer 4 is held by the insulating frame 7, and when the insulating frame 7 is held by the housing 8, each of the first matching layers 4, the insulating frame 7, and the distal end surface of the housing 8 Are arranged on the same plane.

The insulating frame 7 has a first matching layer 4
A notch 10 is provided at a position corresponding to the notch 6, and a part of the surface electrode 2a exposed by the notch 6 and a part of the inner wall of the housing 8 exposed by the notch 10 are connected to the ground electrode. It is electrically connected via a line 11.

On the front surface of the first matching layer 4, a second matching layer 12 is provided. This second matching layer 12
It is formed of, for example, a thin plate-like member or a film-like member made of, for example, a polyamide resin and has a diameter substantially equal to that of the housing 8, and is adhered to the front surface of the first matching layer 4 by, for example, an epoxy adhesive.

The second matching layer 12 is provided with a through hole 13 at a position substantially corresponding to the through hole 5 of the first matching layer 4. Here, the through-hole 13 is formed as a hole having a smaller diameter than the through-hole 5 provided in the first matching layer 4, and is formed, for example, as a hole having a diameter of 0.1 mm.

An acoustic lens 14 is provided on the front surface of the second matching layer 12. The acoustic lens 14 is made of, for example, a silicone resin member molded on a convex surface. The acoustic lens 14 is formed into a convex surface when the sound speed is lower than that of a living body or an acoustic medium (not shown), and is formed into a concave surface when the sound speed is higher than that of the living body or an acoustic medium (not shown).

On the other hand, on the back electrode 2b side of the piezoelectric vibrator 1, a backing layer 15 made of, for example, epoxy resin mixed with ferrite rubber is provided.

The base ends of the insulating frame 7 and the housing 8 are closed by a back cover 16.

In the figure, reference numeral 17 denotes a coaxial cable. One end of the coaxial cable 17 faces the inside of the housing 8, the inner conductor 17a is connected to the back electrode 2b, and the outer conductor 17b is connected to an electrode connection line. 11, connected to the surface electrode 2a via the housing 8. On the other hand, the other end side of the coaxial cable 17 is extended from the base end side surface of the housing 8 to the outside, and is connected to a pulsar /
Connected to receiver circuit.

By the way, as shown in FIGS. 2 and 4, the ultrasonic probe comprises a bonding table 20 and a first pressing member 21.
And the second pressing member 22 are assembled using an adhesive jig provided with the second pressing member 22.

The bonding table 20 includes a cylindrical portion 20a and a flange portion 20 provided on an outer periphery of a base portion of the cylindrical portion 20a.
b. The outer diameter of the cylindrical portion 20 a is formed to be slightly smaller than the inner diameter of the insulating frame 7.
The height of the cylindrical portion 20a from the upper surface of the flange portion 20b is such that the upper surface of the piezoelectric vibrator 1 when the insulating frame 7 is externally fitted to the cylindrical portion 20a and the piezoelectric vibrator 1 is placed. It is designed to be located on the step 9 of the insulating frame 7.
The piezoelectric vibrator 1 is provided on the upper surface of the cylindrical portion 20a.
Is placed at a position corresponding to the through hole 3 of the piezoelectric vibrator 1, and the intake hole 20 c is
It is connected to a vacuum pump (not shown) via an intake pipe 20d.

The first pressing member 21 is formed of a cylindrical member having a pressing surface 21a having substantially the same diameter as that of the first matching layer 4 at the bottom thereof.
4 is a cylindrical member having a curved pressing surface 22a along the lens surface at the bottom.

Next, a method of assembling an ultrasonic probe using the above-described bonding jig will be described. As shown in FIGS. 2 and 3, first, the insulating frame 7 to which the housing 8 is externally fitted is attached to the cylindrical portion 20 a of the adhesive base 20.

Next, the piezoelectric vibrator 1 is placed on the upper surface of the cylindrical portion 20a along the cylindrical portion of the insulating frame 7, and the intake hole 20c is formed.
After being positioned so that the and the through-hole 3 communicate with each other, it is fixed to the inner periphery of the insulating frame 7.

Here, since the inner diameter of the cylindrical portion of the insulating frame 7 is formed to be about 1 mm larger than the outer diameter of the piezoelectric vibrator 1, the positioning accuracy of the piezoelectric vibrator 1 in the insulating frame 7 is improved. And a good insertion property can be obtained without deteriorating.

Next, one end of the ground electrode connection line 11 is soldered to the surface electrode 2a of the piezoelectric vibrator 1, and
The other end of the ground electrode connection wire 11 is soldered to the inner periphery of the housing 8 facing the inside from the cutout 10 of the insulating frame 7 to electrically connect the front surface electrode 2a and the housing 8.

Next, the first matching layer 4 is placed on the step 9 of the insulating frame 7 so that the through-hole 5 communicates with the through-hole 3 of the piezoelectric vibrator 1 and the ground on the surface electrode 2a. In a state where the soldered portion of the electrode connection wire 11 is positioned so as to be exposed to the outside from the cutout portion 6, the electrode connection wire 11 is laminated and bonded to the surface electrode 2a side of the piezoelectric vibrator 1 via an epoxy adhesive.

The curing of the epoxy adhesive for bonding the piezoelectric vibrator 1 and the first matching layer 4 is performed as shown in FIG.
This is performed at room temperature while pressing the first matching layer 4 with the first pressing member 21.

At this time, due to the load by the first pressing member 21, bubbles and excess adhesive between the piezoelectric vibrator 1 and the first matching layer 4 are discharged to the outside from their outer edges. And flows into the through holes 3 and 5. Therefore, the thickness of the adhesive layer between the piezoelectric vibrator 1 and the first matching layer 4 can be reduced, and the adhesive strength between the piezoelectric vibrator 1 and the first matching layer 4 can be increased. Can be.

Here, when the epoxy adhesive is cured, a vacuum pump (not shown) is operated, and the pressure in the through holes 3 and 5 is reduced through the suction holes 20c and the suction pipes 20d, whereby the adhesive through holes 3 are formed. , Promotes inflow into 5,
The thickness of the adhesive layer between the piezoelectric vibrator 1 and the first matching layer 4 can be further reduced, and the adhesive strength between the piezoelectric vibrator 1 and the first matching layer 4 is further increased. Can be.

When the viscosity of the adhesive before curing is sufficiently low, only the load of the first pressing member 21 is sufficient.

Next, in a state where the second matching layer 12 is positioned so that the through hole 13 communicates with the through hole 5 of the first matching layer 4, the first matching layer 4 is bonded via an epoxy adhesive. In addition to laminating and adhering to the front surface, the acoustic lens 14 whose adhesion surface has been subjected to primer treatment is laminated and adhered to the front surface of the second matching layer 12 via an epoxy adhesive.

The first matching layer 4 and the second matching layer 1
The hardening of the epoxy adhesive for bonding the second and second matching layers 12 and the acoustic lens 14 is performed at room temperature while the acoustic lens 14 is pressed by the second pressing member 22 as shown in FIG.

At this time, the first matching layer 4 and the second matching layer 1
2 and between the second matching layer 12 and the acoustic lens 14 and excess adhesive are discharged to the outside from their outer edges and flow into the through holes 5 and 13. . Therefore, the adhesive layer between the first matching layer 4 and the second matching layer 12, and the second matching layer 12 and the acoustic lens 1
4, the thickness of the adhesive layer between the first and second matching layers 4 and 12, and the second matching layer 12 can be reduced.
And the acoustic lens 14 can have a strong adhesive force.

Here, when the epoxy adhesive is cured, a vacuum pump (not shown) is operated, and the pressure in the through holes 3, 5, and 13 is reduced through the suction holes 20c and the suction pipes 20d, so that the adhesive can be penetrated. The adhesion between the first matching layer 4 and the second matching layer 12 and the bonding layer between the second matching layer 12 and the acoustic lens 14 are promoted by promoting the flow into the holes 5 and 13. Can be further reduced, and the adhesive strength between the first matching layer 4 and the second matching layer 12 and between the second matching layer 12 and the acoustic lens 14 can be further increased.

When the viscosity of the adhesive before curing is sufficiently low, only the load of the second pressing member 22 is sufficient.

Next, the above-mentioned assembly is removed from the bonding table 20, the coaxial cable 17 is passed through the insulating frame 7, the base end side of the housing 8, and the internal conductor 17a is connected to the piezoelectric vibrator 1.
Of the external conductor 17
b is soldered to a part of the housing 8.

Next, the insulating frame 7 is filled with an epoxy resin mixed with ferrite rubber and cured to form a packing layer 15 on the back electrode 2 b side of the piezoelectric vibrator 1. Glue.

As described above, according to the present embodiment, the through holes 3, 5, and 13 are provided in the piezoelectric vibrator 1, the first matching layer 4, and the second matching layer 12, respectively. When adhering to each other, air bubbles and excess adhesive can be poured into each of the through holes, the thickness of the adhesive layer between the members can be reduced, and the adhesive strength can be increased. .

The through holes 3, 5 and 13 are provided at positions where they communicate with each other, and the diameter of each through hole is formed such that through hole 3> through hole 5> through hole 13. Therefore, more effectively, bubbles and excess adhesive can be poured into each of the through holes, the thickness of the adhesive layer between the members can be reduced, and the adhesive strength can be increased. .

When the adhesive is cured, a load is applied to the piezoelectric vibrator 1, the first matching layer 4, the second matching layer 12, the acoustic lens 14, and the like by the first and second pressing members 21 and 22. By applying, more effectively, bubbles and excess adhesive can be poured into the respective through-holes, and the thickness of the adhesive layer between the members can be reduced, and the adhesive strength can be increased. Can be.

When the adhesive is cured, the through-holes 3, 5, and 13 are made to have a negative pressure by a vacuum pump or the like, so that bubbles and excess adhesive can be more effectively poured into the respective through-holes. Thus, the thickness of the adhesive layer between the members can be reduced, and the adhesive strength can be increased.

Further, as described above, since each adhesive layer can be formed to be sufficiently thin without bubbles, when a matching layer is provided, a member previously formed to a desired thickness is bonded. It is only necessary to bond with an agent, and the working efficiency at the time of producing an ultrasonic probe can be improved.

Further, since each matching layer is formed by bonding a member previously formed to a desired thickness through an adhesive layer having a sufficient thickness without bubbles, a matching layer having a uniform thickness is formed. Can be formed with high accuracy, and an ultrasonic probe having a sufficient matching layer effective area when the ultrasonic wave radiating side is viewed from the effective surface of the piezoelectric vibrator can be manufactured with high yield.

The piezoelectric vibrator 1, the first matching layer 4, and the second matching layer 12 are made of a material having a small ultrasonic attenuation by connecting the through holes 3, 5, 13 to each other. Even when the acoustic lens 14 is adhered, excess adhesive and air bubbles can be removed through the through holes, and an adhesive layer having no air bubbles and excellent adhesion can be obtained.

As described above, since the film or thin plate having a plurality of through holes and having a thickness of about a quarter wavelength is bonded to the piezoelectric vibrator to form the matching layer, excess bonding is performed via the through holes during bonding. The agent and air bubbles can be discharged. Therefore, the adhesive layer between the piezoelectric vibrator and the matching layer can be formed thin without intervening bubbles and the like, and an ultrasonic probe having excellent ultrasonic characteristics can be easily and stably produced.

Further, a through hole is also provided in the piezoelectric vibrator, and a part of the through hole of the matching layer is adhered and laminated so as to form a continuous through hole formed by the two through holes. By flowing excess adhesive and air bubbles between the small acoustic lens and the continuous through hole, the matching layer and the acoustic lens can be adhered to each other with a thin adhesive layer having no air bubbles or the like. Therefore, it is possible to suppress the deterioration of the ultrasonic characteristics due to the bubbles and the like remaining in the adhesive layer.

In this embodiment, an example in which two matching layers are provided on the ultrasonic probe has been described. However, the present invention is not limited to this, and the ultrasonic probe has one matching layer. Or three or more layers.

In this embodiment, the through holes are also provided in the second matching layer. However, when the acoustic lens is formed of a room-temperature-curable silicone resin or the like without using an adhesive, the second matching layer may be provided with a through hole. The matching layer may not have the through hole.

FIGS. 5 to 10 relate to a second embodiment of the present invention. FIG. 5 is a sectional view of an ultrasonic probe, and FIGS.
7 is a front view of an ultrasonic probe, FIG. 7 is a front view of a composite piezoelectric vibrator provided with a matching layer, FIG. 8 is a sectional view of FIG. 7, and FIG. 9 is a view of another composite piezoelectric vibrator provided with a matching layer. FIG. 10 is a cross-sectional view of FIG.

The ultrasonic probe in this embodiment is
A plurality of piezoelectric elements 100 formed in a prism shape are formed of resin 101.
The composite piezoelectric vibrator 102 is formed so as to be fixed at predetermined intervals. Here, the composite piezoelectric vibrator 102 is formed, for example, by embedding a resin 101 between 0.2 mm × 0.2 mm piezoelectric elements 100 arranged at a pitch of 0.4 mm and then polishing both surfaces. The front surface electrode 103a and the back surface electrode 10 are formed on both surfaces of the composite piezoelectric vibrator 102 by sputtering.
3b is provided.

On the acoustic radiation surface side of the composite piezoelectric vibrator 102, there is provided a matching layer 104 formed to a thickness of a quarter of the driving center frequency. The matching layer 104 is bonded and fixed to the surface electrode 103a side by, for example, an epoxy adhesive. The notch 106 is provided in a part of the outer periphery. A plurality of through-holes 105 (for example, 0.1 mm in diameter) are provided in a portion corresponding to 101.

One end of the ground line 108 is fixed to the front surface electrode 103a exposed to the outside from the cutout portion 106 by a conductive adhesive, while the back surface electrode 103b
, One end of the signal line 107 is bonded and fixed with a conductive adhesive.

The composite piezoelectric vibrator 102 is bonded and fixed to the front surface of a ferrite rubber backing layer 110 which is accommodated and fixed in a cylindrical housing 109 made of stainless steel.

More specifically, the backing layer 1
A concave surface having a radius of curvature of, for example, 15 mm is formed on the front surface of the composite piezoelectric vibrator 10. The composite piezoelectric vibrator 102 is fixed with the back electrode 103 side curved along the concave surface of the backing layer 110.

Further, a notch groove 111 is formed on the side of the backing layer 110 near the bonding portion of the ground line 108.
a, the other end of the ground line 108 is guided to the back side of the backing layer 110 through the notch groove 111a, and a notch groove 111b is provided at a position corresponding to the bonding portion of the signal line 107. This notch groove 111
b through the backing layer 11
0 is guided to the back side.

The signal line 107 and the ground line 10
8 extends from the rear of the housing 109 to the outside, and is connected via a coaxial cable (not shown) to the pulsar /
Connected to receiver circuit (not shown).

An opening formed on the front side of the ultrasonic probe by the cutout grooves 111 a and 111 b is closed by an epoxy resin 113.

Further, the rear part of the housing 109 is provided with a backing layer
In order to fix the signal line 107 and the ground line 108 on the back surface, an epoxy resin 114 is poured and cured.

Further, a back cover 115 made of stainless steel is adhered and fixed to the rear end of the housing 109.

In order to improve the durability of the ultrasonic probe, at least on the front surface of the matching layer 104, a film 116 made of parylene or the like and having excellent water resistance and chemical resistance is formed.

In the ultrasonic probe having the above configuration,
When bonding the matching layer 104 to the composite piezoelectric vibrator 102, as shown in FIGS. 7 and 8, the matching layer 104 is inserted into the through-hole 105 on the composite piezoelectric vibrator 102 coated with a thin adhesive.
Are laminated so as to be positioned on the resin 101 portion of the composite piezoelectric vibrator 102, and are cured and bonded at room temperature by applying a load.

The ultrasonic probe using such a composite piezoelectric vibrator 102 can also obtain substantially the same effects as those of the first embodiment.

Particularly, in this embodiment, when the composite piezoelectric vibrator 102 and the matching layer 104 are bonded, excess adhesive and air can escape from the through holes 105. The composite piezoelectric vibrator 102 and the matching layer 104 can be firmly adhered to each other. Therefore, a probe having excellent ultrasonic characteristics can be easily manufactured.

The resin 101 of the composite piezoelectric vibrator 102
By arranging the matching layer 104 so that the through hole 105 is located in the portion, a structure in which the through hole 105 does not affect the ultrasonic characteristics can be obtained. Therefore, the vibration element 1
When the ultrasonic radiation side is viewed from the effective surface of No. 01, a sufficient matching layer effective area can be secured, and the characteristics of the composite piezoelectric vibrator can be fully utilized.

As described above, also in the ultrasonic probe using the composite piezoelectric vibrator, the through hole of the matching layer is located at the resin portion of the composite piezoelectric body, so that the composite pressure line vibrator and the matching layer can be connected to each other. It is possible to ensure a sufficient matching layer area on the ultrasonic transmitting side as viewed from the micro-vibrator portion of the composite piezoelectric vibrator without intervening air bubbles or the like in the adhesive layer between them, so that ultrasonic transmission can be performed efficiently. it can.

In the present embodiment, an explanation will be given by taking as an example an ultrasonic probe provided with a composite piezoelectric vibrator formed by fixing a plurality of prism-shaped piezoelectric elements at predetermined intervals with a resin. However, it is needless to say that the present invention is not limited to this. For the ultrasonic probe, for example, a composite piezoelectric vibrator formed by fixing cylindrical or strip-shaped piezoelectric elements at predetermined intervals with a resin is used. Is also good.

Here, an example of another composite piezoelectric vibrator will be described with reference to FIGS. 9 and 10. In this composite piezoelectric vibrator 122, a plurality of strip-shaped piezoelectric elements 120 are formed of a resin 121. After being fixed at predetermined intervals and polished on both sides, a front surface electrode 123a and a back surface electrode 123b are provided by, for example, a sputtering method. The matching layer 124 provided on the acoustic radiation surface side of the composite piezoelectric vibrator 122 is formed to have a thickness of a quarter of the driving center frequency.
For example, it is bonded and fixed to the surface electrode 123a side with an epoxy adhesive. A notch 126 is provided in a part of the outer periphery, and a portion corresponding to the resin 121 when overlapping with the composite piezoelectric vibrator 122 is provided. Through hole 125
Are provided.

Further, in this embodiment, the through-hole of the matching layer is provided in the resin portion of the composite piezoelectric vibrator.
In the case where the piezoelectric element portion manufactured by the GA process or the like is a minute (eg, 20 to 100 μm) and the surrounding resin portion also uses a minute (eg, 10 to 100 μm) composite piezoelectric vibrator, Since it is difficult to provide a through-hole provided in the matching layer at a portion corresponding to the resin portion, it is preferable to sparsely provide a small through-hole that does not disturb the ultrasonic characteristics (for example, a through-hole of about 10 μm is Provided at 3 mm intervals).

Further, in the present embodiment, one matching layer is used. However, the present invention is not limited to this, and a plurality of layers can be provided. In this case, if each through-hole is adhered to each matching layer so that each through-hole is located in the resin portion of the composite piezoelectric element, a sufficient matching layer effective area is obtained when the ultrasonic wave emitting side is viewed from the effective surface of the piezoelectric vibrator. Can be secured.

Further, in the present embodiment, the ultrasonic wave is converged by making the composite piezoelectric element a concave surface, but the composite piezoelectric vibrator is arranged on a plane and the acoustic lens is aligned in the same manner as in the first embodiment. It may be provided on the front side of the layer.

The present invention removes excess adhesive and air (bubbles) as a matching layer from the bonding surface between the piezoelectric vibrator and the matching layer.
Because the matching layer was formed using a thin plate or film with through holes, the material and shape of the piezoelectric vibrator, the materials and shapes of the matching layer and the acoustic lens, the structure and manufacturing procedure of the ultrasonic probe, etc. Of course, it is not limited to the above. For example, the present invention can be applied to an array transducer.

[Supplementary Note] (Supplementary Note 1) At least one film-like or thin plate-like matching layer was laminated on the front surface of the piezoelectric vibrator via an adhesive, and an acoustic lens was provided on the front surface of the matching layer. In the ultrasonic probe, a plurality of through holes are provided in the piezoelectric vibrator, and a plurality of through holes are provided in the matching layer, and the positions of these through holes are aligned with the through holes provided in the piezoelectric vibrator. An ultrasonic probe, wherein at least a part of the through holes provided in the layer is set at a position communicating with each other.

(Supplementary Note 2) The ultrasonic probe according to Supplementary Note 1, wherein the through-hole provided in the matching layer is a through-hole smaller in diameter than the through-hole provided in the piezoelectric vibrator.

That is, in the ultrasonic probe according to the above-mentioned appendices 1 and 2, when the acoustic lens is bonded to the front surface of the matching layer, excess adhesive or air bubbles are provided on the piezoelectric vibrator and the matching layer. The adhesive layer can be formed thin without flowing an air layer between the matching layer and the acoustic lens. Therefore, even when bonding an acoustic lens formed of a material having low attenuation of ultrasonic wave propagation such as polymethylpentene or polyamide elastomer, the acoustic lens can be bonded onto the matching layer without intervening air or the like. The sensitivity of the probe can be improved.

(Supplementary Note 3) At least one film-like or thin-plate matching layer is laminated on the ultrasonic wave emitting surface of a composite piezoelectric vibrator having a piezoelectric micro vibrator portion and a resin portion via an adhesive. An ultrasonic probe, wherein a plurality of through holes are provided in the matching layer at positions corresponding to resin portions of the composite piezoelectric vibrator.

That is, the ultrasonic probe according to the appendix 3 is characterized in that the through hole provided in the matching layer does not affect the ultrasonic characteristics, and the composite piezoelectric vibrator and the composite piezoelectric vibrator pass through the through hole. Excess adhesive and bubbles between the matching layer and the matching layer can be removed.

[0089]

As described above, according to the present invention, it is possible to provide an ultrasonic wave in which a uniform matching layer having a desired thickness and a uniform matching layer can be provided on a vibrator with good yield without intervening bubbles or the like between the vibrator and the vibrator. A probe can be provided.

[Brief description of the drawings]

FIGS. 1 to 4 relate to a first embodiment of the present invention, and FIG. 1 is a cross-sectional view showing a main part of an ultrasonic probe.

FIG. 2 is an explanatory view showing a bonding step of a first matching layer.

FIG. 3 is an exploded perspective view showing a part of components of the ultrasonic probe.

FIG. 4 is an explanatory view showing a bonding step of a second matching layer and an acoustic lens.

5 to 10 relate to a second embodiment of the present invention, and FIG. 5 is a cross-sectional view of an ultrasonic probe.

FIG. 6 is a front view of the ultrasonic probe.

FIG. 7 is a front view of a composite piezoelectric vibrator provided with a matching layer.

FIG. 8 is a sectional view of FIG. 7;

FIG. 9 is a front view of another composite piezoelectric vibrator provided with a matching layer.

FIG. 10 is a sectional view of FIG. 9;

FIG. 11 is a sectional view showing a conventional ultrasonic probe.

FIG. 12 is a sectional view taken along line A-A ′ of FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Piezoelectric vibrator 3 ... Through-hole 4 ... First matching layer 5 ... Through-hole 12 ... Second matching layer 13 ... Through-hole 102 ... Composite piezoelectric vibrator 104 ... Matching layer 105 ... Through-hole 122 ... Composite piezoelectric vibration Child 124… Matching layer 125… Through-hole

Claims (1)

[Claims] 1. An ultrasonic transducer, comprising:
An ultrasonic probe comprising a plurality of film-like or thin plate-like matching layers laminated via an adhesive, wherein a plurality of through holes are provided in the matching layer.