Supersonic probe

Abstract

To provide a supersonic probe in which reliability is not damaged and change of an acoustic design is not needed, even if the number of channels of a piezoelectric element is increased.SOLUTION: A supersonic probe is constituted in such a manner that: a flexible circuit board (2) is disposed between a backing material (1) and a plurality of piezoelectric elements (4); each of the plurality of piezoelectric element (4) is formed of a laminate (L) in which a signal electrode layer (4A), a piezoelectric material (4B) and a ground electrode layer (4C) are sequentially laminated in a lamination direction; the signal electrode layer is electrically connected to the flexible circuit board; and in an elevation direction (D2), the flexible circuit board is longer than the piezoelectric material. On an end of the laminate in the elevation direction, a first member (5) formed of an adhesive in which abrasive grains are dispersed, is disposed. The ground electrode layer is electrically connected to the flexible circuit board through a metal foil (6) extending from the surface of the laminate to the surface of the first member and along the side surface of the first member.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic probe in which a plurality of piezoelectric elements are arranged in an array along the azimuth direction. [Background technology]

[0002] In the medical field, ultrasound diagnostic devices using ultrasound images have been put to practical use. Generally, this type of ultrasound diagnostic device transmits an ultrasound beam from an ultrasound probe toward a subject, receives ultrasound echoes from the subject with the ultrasound probe, and generates an ultrasound image by electrically processing the received signals.

[0003] An ultrasonic probe usually has a plurality of piezoelectric elements arranged in an array along the so-called azimuth direction on a backing material. Patent Documents 1 and 2 disclose ultrasonic probes in which a flexible circuit board is disposed between the backing material and the plurality of piezoelectric elements in order to extract signals from the plurality of piezoelectric elements. The signal electrode layers of the piezoelectric elements facing the flexible circuit board are connected to the flexible circuit board, thereby extracting signals from the piezoelectric elements. Metal foil is connected to the ground electrode layers of the piezoelectric elements arranged on the opposite side of the signal electrode layer, and the metal foil is used to ground the piezoelectric elements. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-276060 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-298795 Summary of the Invention [Problem to be solved by the invention]

[0005] However, as the number of channels in a piezoelectric element increases due to the narrower pitch of piezoelectric elements and the wider field of view caused by the recent trend toward higher frequencies, a flexible circuit board that is long in the elevation direction is required to extract signals, and the length of the flexible circuit board in the elevation direction tends to be longer than the length of the piezoelectric element.

[0006] In this way, if the elevation direction length of the flexible circuit board becomes longer than the piezoelectric element, a gap is likely to occur between the metal foil connected to the ground electrode layer of the piezoelectric element and the elevation direction end of the piezoelectric element, and when the flexible circuit board is diced into multiple piezoelectric elements using a cutting blade, the cutting blade may flutter, damaging the piezoelectric elements and compromising the reliability of the ultrasonic probe. If the piezoelectric element were to be lengthened in the elevation direction to fit the flexible circuit board, the bandwidth would change, making it necessary to change the acoustic design. Furthermore, if the number of channels in the piezoelectric element increases, the cutting blade used for dicing becomes more susceptible to wear, and the cut cross section of the piezoelectric element may be damaged, which may impair the reliability of the ultrasonic probe.

[0007] The present invention has been made to solve these conventional problems, and aims to provide an ultrasonic probe that does not lose reliability even when the number of piezoelectric element channels increases, and does not require changes to the acoustic design. [Means for solving the problem]

[0008] The above object can be achieved by the following configuration. [1] An ultrasonic probe in which a plurality of piezoelectric elements are arranged in an array along the azimuth direction on a backing material, A flexible circuit board is disposed between the backing material and the plurality of piezoelectric elements, each of the plurality of piezoelectric elements is formed of a laminate in which a signal electrode layer, a piezoelectric body portion, and a ground electrode layer are sequentially laminated in a lamination direction on a surface of a flexible circuit board; the signal electrode layer is electrically connected to the flexible circuit board; The flexible circuit board is longer than the piezoelectric body in the elevation direction. a first member made of an adhesive having abrasive grains dispersed therein is disposed at an end of the laminate in the elevation direction; The ground electrode layer is an ultrasonic probe electrically connected to the flexible circuit board via a metal foil that extends from the surface of the laminate to the surface of the first member and along the side of the first member in the elevation direction. [2] An ultrasonic probe according to [1], wherein a first member is disposed at each end of the laminate in the elevation direction. [3] The ultrasonic probe according to [1] or [2], wherein the first member has an acoustic attenuation rate equal to or greater than the acoustic attenuation rate of the backing material. [4] An ultrasonic probe according to any one of [1] to [3], wherein the first member is made of a glass adhesive or a ceramic adhesive in which any one of white alumina abrasive, green silicon carbide, and resinoid is dispersed as an abrasive grain. [5] An ultrasonic probe according to any one of [1] to [4], wherein a second member having an acoustic attenuation rate greater than the acoustic attenuation rate of the first member is disposed between the elevation direction end of the laminate and the first member. [6] An ultrasonic probe according to [5], wherein the second member is made of a cushioning material. [7] The ultrasonic probe according to [6], wherein the buffer material is made of silicone resin or epoxy resin. [8] An ultrasonic probe according to any one of [1] to [7], in which a dematching layer having an acoustic impedance higher than the acoustic impedance of the piezoelectric body is disposed between the flexible circuit board and the plurality of piezoelectric elements. [Effects of the Invention]

[0009] According to this invention, a flexible circuit board is arranged between the backing material and the plurality of piezoelectric elements, and each of the plurality of piezoelectric elements is composed of a laminate in which a signal electrode layer, a piezoelectric body portion, and a ground electrode layer are sequentially stacked in a stacking direction on the surface of the flexible circuit board, the signal electrode layer is electrically connected to the flexible circuit board, the flexible circuit board is longer than the piezoelectric body portion in the elevation direction, a first member made of an adhesive having dispersed abrasive grains is arranged at the end of the laminate in the elevation direction, and the ground electrode layer is electrically connected to the flexible circuit board via a metal foil extending from the surface of the laminate to the surface of the first member and along the side surface of the first member in the elevation direction, so that an ultrasonic probe is realized that does not impair reliability even if the number of channels of the piezoelectric elements is increased, and that does not require changes to the acoustic design. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a part of an ultrasonic probe according to a first embodiment of the present invention. [Figure 2] 1 is a cross-sectional view of an ultrasonic probe according to a first embodiment of the present invention. [Figure 3] FIG. 10 is a cross-sectional view of an ultrasonic probe according to a second embodiment of the present invention. [Figure 4] FIG. 10 is a cross-sectional view of an ultrasonic probe according to a third embodiment of the present invention. [Figure 5] FIG. 10 is a cross-sectional view of an ultrasonic probe according to a fourth embodiment of the present invention.

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The following description of the components will be given based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In this specification, the terms "same" and "identical" include a margin of error generally accepted in the technical field.

[0012] Embodiment 1 1 shows the configuration of an ultrasonic probe according to embodiment 1 of the present invention. The ultrasonic probe includes a backing material 1, a flexible circuit board 2 arranged on the backing material 1, a dematching layer 3 arranged on the flexible circuit board 2, and a plurality of piezoelectric elements 4 arranged on the dematching layer 3. The flexible circuit board 2 is formed longer in the elevation direction D2 than the dematching layer 3 and the piezoelectric element 4, and a pair of first members 5 formed on the flexible circuit board 2 are arranged at both ends of the dematching layer 3 and the piezoelectric element 4 in the elevation direction D2.

[0013] The ultrasonic probe further includes a metal foil 6 disposed on the plurality of piezoelectric elements 4 and the pair of first members 5, and an acoustic matching layer 7 disposed on the metal foil 6. The metal foil 6 is bent backward toward the backing material 1 at the corners of the pair of first members 5, and extends to the side of the backing material 1 along the side of each first member 5 in the elevation direction D2. The direction from the backing material 1 toward the acoustic matching layer 7 is referred to as the "front" direction, and the direction from the acoustic matching layer 7 toward the backing material 1 is referred to as the "rear" direction.

[0014] The plurality of piezoelectric elements 4 are arranged in an array along the azimuth direction D1, and a groove G is formed between each of the plurality of piezoelectric elements 4. The groove G is formed to extend from the acoustic matching layer 7 to the surface of the flexible circuit board 2, thereby dividing the dematching layer 3, the pair of first members 5, and the acoustic matching layer 7 into multiple pieces along the azimuth direction D1, similar to the plurality of piezoelectric elements 4. Furthermore, the metal foil 6 in the portions disposed on the tops of the plurality of piezoelectric elements 4 and on the side surfaces of the pair of first members 5 is also divided into multiple pieces along the azimuth direction D1 to match the plurality of piezoelectric elements 4. The groove G is filled with a filler 8.

[0015] The backing material 1 absorbs ultrasonic waves emitted rearward from multiple piezoelectric elements 4, and is made from a base material made of rubber, epoxy resin, polyurethane resin, etc., with fillers made of ferrite, tungsten, manganese, etc. dispersed in it. The flexible circuit board 2 is used to lead out the electrodes of the plurality of piezoelectric elements 4, and has a multi-layer structure in which a plurality of wiring layers are formed. The dematching layer 3 is intended to reflect forward ultrasonic waves emitted backward from the multiple piezoelectric elements 4, and is formed from a material having a higher acoustic impedance than the acoustic impedance of the piezoelectric body portion that constitutes the piezoelectric elements 4, which will be described later, such as tungsten, tungsten carbide, tungsten oxide, or tantalum.

[0016] The acoustic matching layer 7 is a layer for matching the acoustic impedance between the plurality of piezoelectric elements 4 and the subject to facilitate the incidence of ultrasound into the subject, and can be made of a material having an acoustic impedance that is smaller than the acoustic impedance of the piezoelectric body of the piezoelectric elements 4 and larger than the acoustic impedance of the subject. The acoustic matching layer 7 can also have a multi-layer structure so that the acoustic impedance decreases stepwise from the piezoelectric elements 4 toward the subject. The filler 8 is used to fix the positions and postures of the dematching layer 3, the piezoelectric element 4, and the acoustic matching layer 7, which are adjacent in the azimuth direction D1, and is made of, for example, silicone resin, epoxy resin, or the like.

[0017] As shown in Figure 2, each piezoelectric element 4 is formed from a laminate L in which a signal electrode layer 4A, a piezoelectric body portion 4B, and a ground electrode layer 4C are sequentially stacked on the surface of the dematching layer 3 toward the front (stacking direction).

[0018] The piezoelectric portion 4B is made of a known piezoelectric material, and expands and contracts when a voltage is applied to emit ultrasonic waves, and also expands and contracts in response to the propagation of so-called ultrasonic echoes from the outside to generate electrical signals. Examples of piezoelectric materials include piezoelectric ceramics such as PZT (lead zirconate titanate), and polymer materials such as PVDF (polyvinylidene fluoride).

[0019] The signal electrode layer 4A is used to apply a voltage to the piezoelectric body portion 4B and to extract an electrical signal generated when the piezoelectric body portion 2B expands and contracts due to the propagation of an ultrasonic echo. The signal electrode layer 4A is electrically connected to a wiring layer (not shown) of the flexible circuit board 2 via a conductive dematching layer 3. Specifically, the dematching layer 3 has electrode layers (not shown) on the surface facing the multiple piezoelectric elements 4 and the surface facing the flexible circuit board 2, and the signal electrode layer 4A of each piezoelectric element 4 is electrically connected to a wiring layer (not shown) of the flexible circuit board 2 by utilizing the electrode layers arranged on both sides of the dematching layer 3 and the conductivity of the dematching layer 3 itself.

[0020] The ground electrode layer 4C is used to set the reference potential of the piezoelectric body portion 4B to a predetermined ground potential, and is in contact with the metal foil 6 arranged on the top of the piezoelectric element 4 and electrically connected thereto.

[0021] Each of the pair of first members 5 is formed from an adhesive in which abrasive grains are dispersed. Specifically, the first members 5 can be formed from a glass adhesive or ceramic adhesive in which white alumina abrasive, green silicon carbide, or resinoid abrasive grains are dispersed. Furthermore, since the first member 5 is in contact with the side of the piezoelectric element 4 in the elevation direction D2, it is desirable that the first member 5 have an acoustic attenuation rate equal to or greater than that of the backing material 1 in order to suppress the effect on the acoustic characteristics of the piezoelectric element 4. The abrasive grains contained in the first member 5 are used to polish the cutting blade B used when dividing the piezoelectric elements 4 into a plurality of pieces.

[0022] The pair of first members 5 have a height extending forward from the surface of the flexible circuit board 2 that corresponds to the sum of the thicknesses of the dematching layer 3 and the piezoelectric element 4, and the surface of the first member 5 facing forward forms the same plane as the surface of the ground electrode layer 4C of the piezoelectric element 4. Therefore, the metal foil 6 extends in a plane from the piezoelectric element 4 to the first member 5, bends backward at the corners of the first member 5, and extends backward along the side surface of the first member 5 in the elevation direction D2.

[0023] The ultrasonic probe according to the first embodiment of the present invention is provided with such a pair of first members 5, and is therefore configured so that even if the flexible circuit board 2 is formed longer in the elevation direction D2 than the dematching layer 3 and the piezoelectric element 4, no gaps are generated at both ends of the dematching layer 3 and the piezoelectric element 4 in the elevation direction D2. Therefore, when the piezoelectric element 4 is divided into a plurality of piezoelectric elements 4 by dicing using the cutting blade B, it is possible to prevent the cutting blade B from flapping and damaging the piezoelectric element 4. Furthermore, there is no need to lengthen the dematching layer 3 and the piezoelectric element 4 in the elevation direction D2 to match the flexible circuit board 2, and there is no need to change the acoustic design.

[0024] Furthermore, since the first member 5 has a height equivalent to the sum of the thicknesses of the dematching layer 3 and the piezoelectric element 4, when the dematching layer 3 and the piezoelectric element 4 are diced using the cutting blade B, the first member 5 is also cut by the cutting blade B. However, the first member 5 is made of a material containing abrasive grains. As a result, each time the dematching layer 3 and the piezoelectric element 4 are diced, the cutting blade B is polished by the abrasive grains contained in the first member 5. This prevents damage to the cut cross section of the piezoelectric element 4 due to wear of the cutting blade B. This makes it possible to improve the reliability of the ultrasonic probe.

[0025] The ultrasonic probe according to the first embodiment of the present invention can be manufactured as follows. First, the flexible circuit board 2 and the dematching layer 3 are sequentially bonded onto the surface of the backing material 1 using an adhesive or the like, and then a laminate L, in which the signal electrode layer 4A, the piezoelectric portion 4B and the ground electrode layer 4C are sequentially stacked, is bonded onto the surface of the dematching layer 3 using an adhesive or the like. Furthermore, a pair of first members 5 are disposed on and joined to the flexible circuit board 2 adjacent to both ends of the dematching layer 3 and the laminate L in the elevation direction D2. Then, metal foil 6 is bonded onto the surfaces of the laminate L and the pair of first members 5, and further, the metal foil 6 folded at the corners of the pair of first members 5 is bonded onto the side surfaces of the first members 5, the flexible circuit board 2, and the backing material 1. Thereafter, an acoustic matching layer 7 is bonded onto the metal foil 6.

[0026] In this state, by rotating the cutting blade B and moving it relatively in the elevation direction D2, the dematching layer 3, the laminate L and the acoustic matching layer 7 are diced and divided into multiple parts in the azimuth direction D1, and multiple piezoelectric elements 4 are formed. At this time, the pair of first members 5 are also divided into multiple pieces in the azimuth direction D1 to match the multiple piezoelectric elements 4, and the metal foil 6 in the portions arranged on the top of the piezoelectric elements 4 and on the sides of the pair of first members 5 are also divided into multiple pieces in the azimuth direction D1 to match the multiple piezoelectric elements 4. As the pair of first members 5 are divided by the cutting blade B, the abrasive grains contained in the first members 5 perform a polishing process on the cutting blade B every time dicing is performed.

[0027] Finally, the grooves G formed by dicing are filled with a filler 8, thereby completing the manufacture of the ultrasonic probe shown in FIG.

[0028] In the first embodiment described above, the metal foil 6 connected to the ground electrode layers 4C of the plurality of piezoelectric elements 4 extends along the side surfaces of the respective first members 5 in the elevation direction D2 to the side surfaces of the backing material 1, but this is not limiting and the metal foil 6 may be configured to be bent along the front or back surface of the flexible circuit board 2 and connected to a ground wiring layer (not shown) of the flexible circuit board 2. In this case, the metal foil 6 does not need to extend to the side surfaces of the backing material 1.

[0029] Furthermore, the acoustic matching layer 7 disposed on the metal foil 6 is also divided into multiple pieces in the azimuth direction D1 to match the multiple piezoelectric elements 4, but this is not limited to this. For example, dicing may be performed before the acoustic matching layer 7 is disposed to divide the dematching layer 3, the laminate L, the pair of first members 5, and the metal foil 6 into multiple pieces in the azimuth direction D1, and then a single acoustic matching layer 7 extending long in the azimuth direction D1 may be disposed on the divided multiple piezoelectric elements 4 and the metal foil 6.

[0030] Embodiment 2 3 shows the configuration of an ultrasonic probe according to embodiment 2 of the present invention. This ultrasonic probe is the same as the ultrasonic probe according to embodiment 1, except that second members 9 are arranged between the pair of first members 5 and both ends of the dematching layer 3 and the piezoelectric element 4 in the elevation direction D2, respectively. The other members are the same as those of the ultrasonic probe according to embodiment 1.

[0031] That is, the ultrasonic probe of embodiment 2 comprises a flexible circuit board 2 arranged on a backing material 1, a dematching layer 3 arranged on the flexible circuit board 2, and a plurality of piezoelectric elements 4 arranged on the dematching layer 3, and a pair of first members 5 are arranged at both ends of the dematching layer 3 and the piezoelectric elements 4 in the elevation direction D2 via a pair of second members 9 formed on the flexible circuit board 2. A metal foil 6 is disposed on the plurality of piezoelectric elements 4, the pair of second members 9 and the pair of first members 5, and an acoustic matching layer 7 is disposed on the metal foil 6.

[0032] The pair of second members 9 each have the same height as the first member 5 and have an acoustic attenuation rate greater than that of the first member 5. Specifically, the second members 9 can be formed from a buffer material made of silicone resin or epoxy resin, similar to the filler 8 filled in the grooves G.

[0033] In this way, by interposing the second member 9, which has an acoustic attenuation rate greater than that of the first member 5, between the piezoelectric element 4 and the first member 5, it is possible to suppress the effect on the acoustic properties of the piezoelectric element 4 caused by direct contact with the first member 5, and it is possible to further improve the reliability of the ultrasonic probe.

[0034] In the ultrasonic probe according to the second embodiment, even if the flexible circuit board 2 is formed longer in the elevation direction D2 than the dematching layer 3 and the piezoelectric elements 4, no gaps are generated at both ends of the dematching layer 3 and the piezoelectric elements 4 in the elevation direction D2, and it is possible to prevent the cutting blade B from flapping and damaging the piezoelectric elements 4 when dicing into a plurality of piezoelectric elements 4 using the cutting blade B. Furthermore, there is no need to lengthen the dematching layer 3 and the piezoelectric elements 4 in the elevation direction D2 to match the flexible circuit board 2, and there is no need to change the acoustic design.

[0035] Furthermore, each time the dematching layer 3 and the piezoelectric element 4 are diced, the cutting blade B is polished by the abrasive grains contained in the first member 5, thereby preventing damage to the cut cross section of the piezoelectric element 4 due to wear of the cutting blade B.

[0036] Embodiment 3 4 shows the configuration of an ultrasonic probe according to embodiment 3 of the present invention. In this ultrasonic probe, instead of a pair of first members 5 being arranged at both ends of the dematching layer 3 and the piezoelectric element 4 in the elevation direction D2 in the ultrasonic probe of embodiment 1, a first member 5 formed on a flexible circuit board 2 is arranged only at one end of the dematching layer 3 and the piezoelectric element 4 in the elevation direction D2. The other members are the same as those in the ultrasonic probe of embodiment 1.

[0037] That is, the ultrasonic probe according to the third embodiment includes a flexible circuit board 2 arranged on a backing material 1, a dematching layer 3 arranged on the flexible circuit board 2, and a plurality of piezoelectric elements 4 arranged on the dematching layer 3, and a first member 5 is arranged at one end in the elevation direction D2 of the dematching layer 3 and the piezoelectric elements 4. Furthermore, a metal foil 6 is arranged on the plurality of piezoelectric elements 4 and the first member 5, and an acoustic matching layer 7 is arranged on the metal foil 6.

[0038] In the ultrasonic probe according to the third embodiment, even if the flexible circuit board 2 is formed longer in the elevation direction D2 than the dematching layer 3 and the piezoelectric elements 4, no gaps are generated at the ends of the dematching layer 3 and the piezoelectric elements 4 in the elevation direction D2, and it is possible to prevent the cutting blade B from flapping and damaging the piezoelectric elements 4 when dicing the flexible circuit board 2 into a plurality of piezoelectric elements 4. Furthermore, there is no need to lengthen the dematching layer 3 and the piezoelectric elements 4 in the elevation direction D2 to match the flexible circuit board 2, and no change in the acoustic design is required.

[0039] Furthermore, each time the dematching layer 3 and the piezoelectric element 4 are diced, the cutting blade B is polished by the abrasive grains contained in the first member 5, thereby preventing damage to the cut cross section of the piezoelectric element 4 due to wear of the cutting blade B. In addition, in order to prevent damage to the piezoelectric element 4 due to fluttering of the cutting blade B during dicing, it is desirable to move the cutting blade B relatively in the elevation direction D2 from one end where the first member 5 is located to the other end where the first member 5 is not located, as shown in Figure 4, of both ends of the dematching layer 3 and the piezoelectric element 4 in the elevation direction D2.

[0040] Furthermore, the third embodiment can be applied to the ultrasonic probe of the second embodiment, and the second member 9 and the first member 5 can be disposed only at one end of the dematching layer 3 and the piezoelectric element 4 in the elevation direction D2.

[0041] Embodiment 4 5 shows the configuration of an ultrasonic probe according to embodiment 4 of the present invention. This ultrasonic probe is the same as the ultrasonic probe according to embodiment 1 except that the dematching layer 3 is omitted and multiple piezoelectric elements 4 are arranged directly on the surface of a flexible circuit board 2. The other components are the same as those of the ultrasonic probe according to embodiment 1.

[0042] That is, the ultrasonic probe according to the fourth embodiment includes a flexible circuit board 2 arranged on a backing material 1, and a plurality of piezoelectric elements 4 arranged on the flexible circuit board 2, and a pair of first members 5 are arranged on both ends in the elevation direction D2 of the piezoelectric elements 4. Furthermore, a metal foil 6 is arranged on the plurality of piezoelectric elements 4 and the pair of first members 5, and an acoustic matching layer 7 is arranged on the metal foil 6.

[0043] In the ultrasonic probe according to the fourth embodiment, even if the flexible circuit board 2 is formed to be longer in the elevation direction D2 than the piezoelectric element 4, no gaps are generated at the ends of the piezoelectric element 4 in the elevation direction D2, and it is possible to prevent the cutting blade B from flapping and damaging the piezoelectric element 4 when dividing the piezoelectric element 4 into a plurality of piezoelectric elements 4 by dicing using the cutting blade B. Furthermore, there is no need to lengthen the piezoelectric element 4 in the elevation direction D2 to match the flexible circuit board 2, and there is no need to change the acoustic design.

[0044] Furthermore, each time the piezoelectric element 4 is diced, the cutting blade B is polished by the abrasive grains contained in the first member 5, thereby preventing damage to the cut cross section of the piezoelectric element 4 due to wear of the cutting blade B.

[0045] However, if multiple piezoelectric elements 4 are arranged on the surface of the dematching layer 3 as in embodiment 1, the dematching layer 3 can reflect ultrasonic waves emitted backward from the multiple piezoelectric elements 4 forward, thereby forming a high-performance ultrasonic probe. Moreover, the fourth embodiment can be applied to the ultrasonic probe of the second or third embodiment, and the dematching layer 3 can be omitted. [Explanation of symbols]

[0046] 1 backing material, 2 flexible circuit board, 3 dematching layer, 4 piezoelectric element, 4A signal electrode layer, 4B piezoelectric body portion, 4C ground electrode layer, 5 first member, 6 metal foil, 7 acoustic matching layer, 8 filler, 9 second member, D1 azimuth direction, D2 elevation direction, G groove, L laminate, B cutting blade.

Claims

1. An ultrasonic probe in which a plurality of piezoelectric elements are arranged in an array along an azimuth direction on a backing material, a flexible circuit board is disposed between the backing material and the plurality of piezoelectric elements; each of the plurality of piezoelectric elements is formed of a laminate in which a signal electrode layer, a piezoelectric body portion, and a ground electrode layer are sequentially laminated in a lamination direction on a surface of the flexible circuit board; the signal electrode layer is electrically connected to the flexible circuit board; the flexible circuit board is longer than the piezoelectric body in the elevation direction; a first member made of an adhesive having abrasive grains dispersed therein is disposed at an end of the laminate in the elevation direction; The ground electrode layer is electrically connected to the flexible circuit board via a metal foil extending from the surface of the laminate to the surface of the first member and along the side of the first member in the elevation direction.

2. 2. The ultrasonic probe according to claim 1, wherein the first members are disposed at both ends of the laminate in the elevation direction.

3. 2. The ultrasonic probe according to claim 1, wherein the first member has an acoustic attenuation rate equal to or greater than that of the backing material.

4. 2. The ultrasonic probe according to claim 1, wherein the first member is made of a glass adhesive or a ceramic adhesive in which any one of white alumina abrasive, green silicon carbide, and resinoid is dispersed as the abrasive grains.

5. 2. The ultrasonic probe according to claim 1, wherein a second member having an acoustic attenuation rate greater than that of the first member is disposed between the end of the laminate in the elevation direction and the first member.

6. 6. The ultrasonic probe according to claim 5, wherein the second member is made of a buffer material.

7. 7. The ultrasonic probe according to claim 6, wherein the buffer material is made of silicone resin or epoxy resin.

8. An ultrasonic probe according to any one of claims 1 to 7, wherein a dematching layer having an acoustic impedance higher than an acoustic impedance of the piezoelectric body portion is disposed between the flexible circuit board and the plurality of piezoelectric elements.

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