Ultrasonic vibrator and medical device

Abstract

This ultrasonic transducer comprises: a piezoelectric element layer that has a piezoelectric element which sends and receives ultrasonic waves; a dematching layer that is laminated on the piezoelectric element layer and that reflects at least a portion of the ultrasonic waves, said dematching layer having a first member and a second member which has a higher electrical conductivity than the first member; and a wire that is electrically connected to the second member. Thus, the present invention provides an ultrasonic transducer that reduces noise and prevents connection failure.

Description

Ultrasonic vibrator, medical device, and method for manufacturing ultrasonic vibrator

[0001] The present invention relates to an ultrasonic transducer, a medical device, and a method for manufacturing an ultrasonic transducer.

[0002] Conventionally, ultrasonic vibrators having piezoelectric elements that transmit and receive ultrasonic waves have been known (see, for example, Patent Document 1). In the ultrasonic vibrator of Patent Document 1, a dematching layer that reflects ultrasonic waves and an FPC (Flexible Printed Circuit) that transmits and receives electrical signals to and from the piezoelectric element are laminated on the back surface side of the piezoelectric element.

[0003] JP 2013-77940 A

[0004] However, when an FPC is laminated on the back surface of the piezoelectric element, ultrasonic waves reflected by the FPC become noise, which causes a problem of degrading the quality of the ultrasonic image.

[0005] Alternatively, a conductive electrode layer may be formed on the surface of the dematching layer by plating, and a wire may be soldered to the electrode layer. However, when soldering the wire, the electrode layer may melt and be absorbed by the solder, which may result in a poor connection.

[0006] The present invention has been made in view of the above, and an object of the present invention is to provide an ultrasonic transducer, a medical device, and a method for manufacturing an ultrasonic transducer that reduce noise and prevent connection failures.

[0007] In order to solve the above-mentioned problems and achieve the object, an ultrasonic vibrator according to one aspect of the present invention comprises a piezoelectric element layer having a piezoelectric element that transmits and receives ultrasonic waves, a dematching layer laminated on the piezoelectric element layer and that reflects at least a portion of the ultrasonic waves, the dematching layer having a first member and a second member that is more conductive than the first member, and a wire electrically connected to the second member.

[0008] In the ultrasonic transducer according to one aspect of the present invention, the wire is made of a material different from that of the second member.

[0009] In the ultrasonic transducer according to one aspect of the present invention, the wire is electrically connected to the second member by soldering.

[0010] Moreover, an ultrasonic transducer according to one aspect of the present invention includes a backing material that encompasses the wire and absorbs or attenuates the ultrasonic waves.

[0011] In the ultrasonic transducer according to one aspect of the present invention, the first member is made of a material having a higher acoustic impedance than the second member.

[0012] In addition, in an ultrasonic vibrator according to one aspect of the present invention, the second member has a first surface located between the piezoelectric element layer and the first member, a second surface located on the opposite side of the first surface across the first member, and a third surface connected to the first surface and the second surface.

[0013] In addition, in an ultrasonic transducer according to one aspect of the present invention, the thickness of the second surface is ⅓ or less of the thickness of the dematching layer.

[0014] In addition, in an ultrasonic vibrator according to one aspect of the present invention, the thickness of the second surface is greater than the thickness of the first surface and the thickness of the third surface, and the wire is electrically connected to the second surface.

[0015] In addition, in an ultrasonic vibrator according to one aspect of the present invention, the thickness of the third surface is greater than the thickness of the first surface and the thickness of the second surface, and the wire is electrically connected to the third surface.

[0016] In addition, in an ultrasonic vibrator according to one aspect of the present invention, an uneven surface is formed between the first member and the second member, and the wire is electrically connected to the surface of the second member on which the uneven surface is formed.

[0017] In addition, in an ultrasonic vibrator according to one aspect of the present invention, the first member and the second member are made of the same material, and the concentration of the conductive material contained in the second member is higher than the concentration of the conductive material contained in the first member.

[0018] In addition, in an ultrasonic vibrator according to one aspect of the present invention, the first member includes at least one of tungsten (W), cobalt (Co), nickel (Ni), titanium (Ti), chromium (Cr), molybdenum (Mo), tantalum (Ta), and carbon (C).

[0019] In addition, in an ultrasonic vibrator according to one aspect of the present invention, the second member includes at least one of gold (Au), silver (Ag), copper (Cu), cobalt (Co), nickel (Ni), titanium (Ti), chromium (Cr), molybdenum (Mo), tantalum (Ta), and carbon (C).

[0020] A medical device according to one aspect of the present invention includes an ultrasound transducer and an insertion section having the ultrasound transducer disposed at a tip thereof and to be inserted into a subject.

[0021] Moreover, the medical device according to one aspect of the present invention includes an imaging unit that images the inside of the subject.

[0022] Furthermore, a method for manufacturing an ultrasonic vibrator according to one aspect of the present invention includes preparing a piezoelectric element layer having a piezoelectric element that transmits and receives ultrasonic waves, and a dematching layer that reflects at least a portion of the ultrasonic waves, the dematching layer having a first member and a second member that is more conductive than the first member, stacking the dematching layer on the piezoelectric element layer, and electrically connecting a wire to the second member.

[0023] In addition, in a method for manufacturing an ultrasonic vibrator according to one aspect of the present invention, the second member has a first surface located between the piezoelectric element layer and the first member, a second surface located on the opposite side of the first surface across the first member, and a third surface connected to the first surface and the second surface.

[0024] Furthermore, a method for manufacturing an ultrasonic vibrator according to one aspect of the present invention includes preparing a dematching layer in which the thickness of the second surface is greater than the thickness of the first surface and the thickness of the third surface, and electrically connecting the wire to the second surface.

[0025] In addition, a method for manufacturing an ultrasonic vibrator according to one aspect of the present invention includes making the thickness of the second surface of a laminate in which the dematching layer is laminated on the piezoelectric element layer thicker than the thickness of the first surface and the thickness of the third surface by plating, and electrically connecting the wire to the second surface.

[0026] According to the present invention, it is possible to realize an ultrasonic transducer, a medical device, and a method for manufacturing an ultrasonic transducer that reduce noise and prevent connection failures.

[0027] FIG. 1 is a schematic diagram showing the entire endoscope system. FIG. 2 is a perspective view showing the tip of the insertion section. FIG. 3 is a cross-sectional view showing the configuration of an ultrasonic transducer including an ultrasonic transducer according to a first embodiment. FIG. 4 is a cross-sectional view corresponding to line A-A in FIG. 3. FIG. 5 is a flowchart showing an outline of steps in a method for manufacturing an ultrasonic transducer according to the first embodiment. FIG. 6 is a diagram showing how components are prepared. FIG. 7 is a diagram showing how components are stacked. FIG. 8 is a diagram showing how wires are connected. FIG. 9 is a flowchart showing an outline of steps in a method for manufacturing an ultrasonic transducer according to a second embodiment. FIG. 10 is a diagram showing how components are prepared. FIG. 11 is a diagram showing how components are stacked. FIG. 12 is a cross-sectional view of an ultrasonic transducer according to a third embodiment. FIG. 13 is a diagram showing how components are prepared. FIG. 14 is a diagram showing how components are stacked. FIG. 15 is a diagram showing how wires are connected. FIG. 16 is a flowchart showing an outline of steps in a method for manufacturing an ultrasonic transducer according to a fourth embodiment. FIG. 17 is a cross-sectional view of an ultrasonic transducer according to a fifth embodiment. FIG. 18 is a diagram showing how components are prepared. Fig. 19 is a diagram showing how each component is stacked. Fig. 20 is a diagram showing how wires are connected. Fig. 21 is a flowchart showing an overview of steps in a method for manufacturing an ultrasonic vibrator according to embodiment 6. Fig. 22 is a diagram showing how components are prepared. Fig. 23 is a diagram showing how each component is stacked. Fig. 24 is a cross-sectional view of an ultrasonic vibrator according to embodiment 7. Fig. 25 is a cross-sectional view of an ultrasonic vibrator according to embodiment 8. Fig. 26 is a cross-sectional view of an ultrasonic vibrator according to embodiment 9.

[0028] Hereinafter, embodiments of an ultrasonic transducer, a medical device, and a method for manufacturing an ultrasonic transducer according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to these embodiments. The present invention can be generally applied to ultrasonic transducers, medical devices, and methods for manufacturing ultrasonic transducers.

[0029] In addition, in the drawings, the same or corresponding elements are appropriately designated by the same reference numerals. It should be noted that the drawings are schematic, and the dimensional relationships and ratios of each element may differ from the actual situation. The dimensional relationships and ratios may also differ between the drawings.

[0030] (Embodiment 1) [Schematic Configuration of Endoscope System] Fig. 1 is a schematic diagram showing the entire endoscope system. The endoscope system 1 as a medical device is a system that performs ultrasound diagnosis and treatment inside a subject such as a human using an ultrasound endoscope. As shown in Fig. 1, this endoscope system 1 includes an ultrasound endoscope 2, an ultrasound observation device 3, an endoscopic observation device 4, and a display device 5.

[0031] The ultrasonic endoscope 2 is partially insertable into a subject, and has the functions of transmitting ultrasonic pulses (acoustic pulses) toward the body wall of the subject, receiving ultrasonic echoes reflected by the subject, and outputting echo signals, as well as capturing images of the inside of the subject and outputting image signals. The detailed configuration of the ultrasonic endoscope 2 will be described later.

[0032] The ultrasound observation device 3 is electrically connected to the ultrasound endoscope 2 via an ultrasound cable 31, and outputs pulse signals to the ultrasound endoscope 2 via the ultrasound cable 31, while inputting echo signals from the ultrasound endoscope 2. The ultrasound observation device 3 then performs predetermined processing on the echo signals to generate an ultrasound image.

[0033] The endoscopic connector 9 of the ultrasonic endoscope 2 is detachably connected to the endoscopic observation device 4. As shown in FIG.

[0034] The video processor 41 receives an image signal from the ultrasonic endoscope 2 via the endoscope connector 9. The video processor 41 then performs predetermined processing on the image signal to generate an endoscopic image.

[0035] The light source device 42 supplies illumination light for illuminating the inside of the subject to the ultrasonic endoscope 2 via the endoscope connector 9 .

[0036] The display device 5 is configured using a liquid crystal display, an organic electroluminescence (EL) display, a CRT (cathode ray tube), or a projector, and displays ultrasound images generated by the ultrasound observation device 3, endoscopic images generated by the endoscopic observation device 4, etc.

[0037] [Configuration of Ultrasonic Endoscope] Next, a description will be given of the configuration of the ultrasonic endoscope 2. As shown in FIG. 1 , the ultrasonic endoscope 2 includes an insertion section 6, an operation section 7, a universal cord 8, and an endoscope connector 9.

[0038] 2 is a perspective view showing the tip of the insertion portion 6. In the following description of the configuration of the insertion portion 6, the tip side of the insertion portion 6 (the tip side in the direction of insertion into the subject) will be referred to simply as the "tip side," and the base side of the insertion portion 6 (the side away from the tip of the insertion portion 6) will be referred to as the "base side."

[0039] 1 or 2, the insertion section 6 is a portion that is inserted into the subject and includes an ultrasonic probe 10 disposed at the tip, a rigid member 61 connected to the base end of the ultrasonic probe 10, a bending section 62 connected to the base end of the rigid member 61 and capable of bending, and a flexible tube 63 (FIG. 1) connected to the base end of the bending section 62 and having flexibility.

[0040] Inside the insertion section 6, the operating section 7, the universal cord 8, and the endoscopic connector 9, a light guide for transmitting illumination light supplied from the light source device 42, a transducer cable for transmitting pulse signals and echo signals, and a signal cable for transmitting image signals are routed, and conduits for circulating fluids are also provided.

[0041] The hard member 61 is a hard member made of a resin material, etc. At the tip of the hard member 61, as shown in Fig. 2, an illumination unit 611 that irradiates illumination light into the subject, an imaging unit 612 that images the inside of the subject, and a treatment tool channel 613 that allows a treatment tool to protrude from the tip of the insertion section 6 are arranged.

[0042] The illumination unit 611 is located at the tip and includes a light guide that transmits the illumination light output by the light source device 42 to the tip of the insertion section 6, and an illumination lens that irradiates the illumination light emitted from the exit end of the light guide into the subject.

[0043] The imaging unit 612 captures images of the inside of the subject. The imaging unit 612 has an objective optical system that condenses light (subject image) that is irradiated into the subject and reflected within the subject, and an imaging element that captures the subject image condensed by the objective optical system. An image signal captured by the imaging element is transmitted to the endoscopic observation device 4 (video processor 41) via a signal cable.

[0044] The treatment tool channel 613 is a passage through which a treatment tool such as a puncture needle inserted inside the insertion portion 6 is projected to the outside.

[0045] The operation unit 7 is connected to the proximal end side of the insertion unit 6 and is a part that receives various operations from a doctor, etc. As shown in Fig. 1, the operation unit 7 includes a bending knob 71 for bending the bending portion 62, and a plurality of operation members 72 for performing various operations.

[0046] The operating section 7 is also provided with a treatment tool insertion port 73 (FIG. 1) that communicates with the treatment tool channel 613 via a tube provided inside the bending section 62 and the flexible tube 63, and through which the treatment tool is inserted into the tube.

[0047] The universal cord 8 extends from the operation unit 7 and is a cord on which a light guide, a transducer cable, a signal cable, and a tube that constitutes part of a duct are arranged.

[0048] The endoscope connector 9 is provided at the end of the universal cord 8. The endoscope connector 9 is connected to the ultrasound cable 31 and is also inserted into the endoscopic observation device 4 to be connected to the video processor 41 and the light source device 42.

[0049] [Configuration of Ultrasonic Probe] Next, the configuration of the ultrasonic probe 10 will be described. Fig. 3 is a cross-sectional view showing the configuration of an ultrasonic transducer including an ultrasonic transducer according to embodiment 1. As shown in Fig. 3, the ultrasonic probe 10 is a convex type ultrasonic transducer including a plurality of ultrasonic transducers 100 arranged in an arc shape, but may also be a radial type or linear type ultrasonic transducer.

[0050] [Configuration of Ultrasonic Vibrator] Next, the configuration of the ultrasonic vibrator 100 will be described. Fig. 4 is a cross-sectional view corresponding to line A-A in Fig. 3. As shown in Fig. 4, the ultrasonic vibrator 100 includes a piezoelectric element layer 101, a dematching layer 102, a wire 103, a backing material 104, a first acoustic matching layer 105, and a second acoustic matching layer 106.

[0051] The piezoelectric element layer 101 has piezoelectric elements that transmit and receive ultrasonic waves. Each piezoelectric element layer 101 is configured as an elongated rectangular parallelepiped with its long sides extending in the left-right direction in FIG. 4 . The piezoelectric element layer 101 converts a pulse signal input via the wire 103 and the dematching layer 102 into an ultrasonic pulse and transmits it to the subject. The piezoelectric element layer 101 also converts an ultrasonic echo reflected by the subject into an electrical echo signal expressed by a voltage change and outputs it to the wire 103 via the dematching layer 102.

[0052] Piezoelectric elements are formed using PMN-PT single crystals, PMN-PZT single crystals, PZN-PT single crystals, PIN-PZN-PT single crystals, or relaxor-based materials. PMN-PT single crystals are an abbreviation for a solid solution of magnesium lead niobate and lead titanate. PMN-PZT single crystals are an abbreviation for a solid solution of magnesium lead niobate and lead zirconate titanate. PZN-PT single crystals are an abbreviation for a solid solution of zinc lead niobate and lead titanate. PIN-PZN-PT single crystals are an abbreviation for a solid solution of indium lead niobate, zinc lead niobate, and lead titanate. Relaxor-based materials are a general term for ternary piezoelectric materials in which lead zirconate titanate (PZT) is added with a lead-based complex perovskite relaxor material to increase the piezoelectric constant and dielectric constant. Lead-based complex perovskite is Pb(B1,B2)O ３ where B1 is either magnesium, zinc, indium or scandium, and B2 is either niobium, tantalum or tungsten. These materials have excellent piezoelectric effects, which allows the electrical impedance to be kept low even when the device is miniaturized.

[0053] The dematching layer 102 is laminated on the piezoelectric element layer 101 and reflects at least a portion of the ultrasonic wave. The dematching layer 102 has a first member 121 and a second member 122.

[0054] The first member 121 is made of a material having a higher acoustic impedance than the second member 122. The first member 121 is, for example, tungsten carbide, which has a high acoustic impedance, but may also contain at least one of tungsten (W), cobalt (Co), nickel (Ni), titanium (Ti), chromium (Cr), molybdenum (Mo), tantalum (Ta), and carbon (C).

[0055] The second member 122 has higher conductivity than the first member 121. The second member 122 is made of, for example, gold (Au), but may also contain at least one of silver (Ag), copper (Cu), cobalt (Co), nickel (Ni), titanium (Ti), chromium (Cr), molybdenum (Mo), tantalum (Ta), and carbon (C).

[0056] The second member 122 has a first surface 1221 located between the piezoelectric element layer 101 and the first member 121, a second surface 1222 located on the opposite side of the first member 121 from the first surface 1221, and a third surface 1223 connected to the first surface 1221 and the second surface 1222. The thickness of the second surface 1222 is greater than the thickness of the first surface 1221 and the thickness of the third surface 1223. The thickness of the second surface 1222 is preferably equal to or less than half the thickness of the dematching layer 102, and more preferably equal to or less than one-third of the thickness of the dematching layer 102. By not making the thickness of the second surface 1222 too thick, it is possible to prevent a reduction in the ultrasonic wave reflection effect of the dematching layer 102. Note that the thickness of the second surface 1222 refers to the dimension of the second surface 1222 in a direction perpendicular to the second surface 1222. Similarly, the thickness of the first surface 1221 and the thickness of the third surface 1223 are the dimensions of the first surface 1221 and the third surface 1223 in a direction perpendicular to the first surface 1221 and the third surface 1223. Furthermore, the thickness of the dematching layer 102 is the dimension of the dematching layer 102 in the direction in which the dematching layer 102 and the piezoelectric element layer 101 are stacked.

[0057] One end of the wire 103 is electrically connected to the second surface 1222 of the second member 122 by soldering, but the electrical connection may also be made by ultrasonic fusion, brazing, or the like. The other end of the wire 103 is electrically connected to the ultrasound observation device 3 via the universal cord 8 and the ultrasound cable 31, which are not shown in FIG. 4 . The wire 103 transmits pulse signals output from the ultrasound observation device 3 to each piezoelectric element layer 101, and also transmits echo signals output from each piezoelectric element layer 101 to the ultrasound observation device 3. The wire 103 is made of a different material from the second member 122.

[0058] The backing material 104 encompasses the wire 103 and absorbs or attenuates unnecessary ultrasonic waves generated by the operation of the piezoelectric element layer 101. The backing material 104 is formed using a material with a high absorption rate or attenuation rate, such as epoxy resin with a filler such as alumina or zirconia dispersed therein, or rubber with the above-mentioned fillers dispersed therein. Note that the backing material 104 may not be provided depending on the characteristics of the piezoelectric element layer 101 and the object to be observed.

[0059] The first acoustic matching layer 105 and the second acoustic matching layer 106 are positioned relative to the piezoelectric element layer 101 in the direction in which each piezoelectric element layer 101 transmits ultrasound (upward in FIG. 4 ). As shown in FIG. 3 , the first acoustic matching layer 105 and the second acoustic matching layer 106 are continuous along the arrangement direction of the plurality of piezoelectric element layers 101, and hold each piezoelectric element layer 101 in an arc shape. The first acoustic matching layer 105 and the second acoustic matching layer 106 match the acoustic impedance between the piezoelectric element layer 101 and the observation target in order to efficiently transmit sound (ultrasound) between the piezoelectric element layer 101 and the observation target. The first acoustic matching layer 105 and the second acoustic matching layer 106 are made of different materials. Although the first embodiment will be described as having two acoustic matching layers (the first acoustic matching layer 105 and the second acoustic matching layer 106), an acoustic matching layer may be omitted, one layer may be provided, or three or more layers may be provided depending on the characteristics of the piezoelectric element layer 101 and the observation target.

[0060] [Method of Manufacturing Ultrasonic Vibrator] Next, a method of manufacturing an ultrasonic vibrator will be described. Fig. 5 is a flowchart showing an outline of the steps of the method of manufacturing an ultrasonic vibrator according to the first embodiment.

[0061] As shown in Figure 5, members used to manufacture the ultrasonic vibrator 100 are prepared (step S1). Figure 6 is a diagram showing the preparation of the members. As shown in Figure 6, a piezoelectric element layer 101, a dematching layer 102, a backing material 104, a first acoustic matching layer 105, and a second acoustic matching layer 106 are prepared. At this time, the thickness of the second surface 1222 of the second member 122 is made thicker than the thicknesses of the first surface 1221 and the third surface 1223. This can be achieved by performing plating, sputtering, or the like when forming the second member 122 by plating the surface of the first member 121 so that the thickness of the second surface 1222 is thicker than the thicknesses of the first surface 1221 and the third surface 1223.

[0062] Next, the piezoelectric element layer 101, the dematching layer 102, the backing material 104, the first acoustic matching layer 105, and the second acoustic matching layer 106 are laminated using an adhesive or the like (step S2). Fig. 7 is a diagram showing how each component is laminated. As shown in Fig. 7, a laminate is formed in which the dematching layer 102 to the second acoustic matching layer 106 are laminated.

[0063] Thereafter, the laminate formed in step S2 is diced with a dicing saw (step S3), whereby the dematching layer 102 and the piezoelectric element layer 101 are cut, and the plate-like piezoelectric element layer 101 becomes a rectangular parallelepiped.

[0064] Then, wiring is attached to the ultrasonic transducer 100 (step S4). Fig. 8 is a diagram showing how the wires are connected. As shown in Fig. 8, the wires 103 are electrically connected to the second surface 1222 of the second member 122 by soldering.

[0065] Finally, with the first acoustic matching layer 105 and the second acoustic matching layer 106 curved in the arc shape shown in Fig. 3, the backing material 104 is filled on the side of the piezoelectric element layer 101 where the dematching layer 102 is laminated (step S5). As a result, the ultrasonic probe 10 having a plurality of ultrasonic transducers 100 is manufactured.

[0066] According to the first embodiment described above, in step S4, when the wire 103 is electrically connected to the second surface 1222 of the second member 122 by soldering, the thickness of the second surface 1222 is increased. As a result, it is possible to prevent the second member 122 from melting and being absorbed by the solder (being eaten by the solder), and it is possible to prevent poor connection.

[0067] Furthermore, according to the first embodiment, the ultrasonic transducer 100 does not have an FPC, and therefore noise caused by reflection from the FPC is prevented from occurring.

[0068] Furthermore, according to the first embodiment, the dematching layer 102 and the piezoelectric element layer 101 are cut by dicing, and the first acoustic matching layer 105 and the second acoustic matching layer 106, which are located outside the piezoelectric elements, are used as references for bending. This makes it possible to maintain the pitch between the piezoelectric elements when bending. In contrast, if the piezoelectric element layer 101, the first acoustic matching layer 105, and the second acoustic matching layer 106 are cut by dicing, and the bending is performed using an FPC or the like, which is located inside the piezoelectric elements, as a reference, the pitch between the piezoelectric elements increases when bending, making it impossible to maintain the pitch.

[0069] Second Embodiment The configuration of an ultrasonic vibrator 100 according to a second embodiment is the same as that of the first embodiment, and therefore description thereof will be omitted. Fig. 9 is a flowchart showing an outline of steps in a method for manufacturing an ultrasonic vibrator according to the second embodiment.

[0070] As shown in Fig. 9, members used to manufacture the ultrasonic vibrator 100 are prepared (step S11). Fig. 10 is a diagram showing the preparation of the members. As shown in Fig. 10, a piezoelectric element layer 101, a dematching layer 102, a backing material 104, a first acoustic matching layer 105, and a second acoustic matching layer 106 are prepared. The first surface 1221, the second surface 1222, and the third surface 1223 of the prepared second member 122 have the same thickness. Note that the thickness of each surface refers to the dimension of each surface in the direction perpendicular to each surface.

[0071] Next, the piezoelectric element layer 101, the dematching layer 102, the backing material 104, the first acoustic matching layer 105, and the second acoustic matching layer 106 are laminated using an adhesive or the like (step S2). Fig. 11 is a diagram showing how each component is laminated. As shown in Fig. 11, a laminate is formed in which the dematching layer 102 to the second acoustic matching layer 106 are laminated.

[0072] Thereafter, the laminate formed in step S2 is diced with a dicing saw (step S3), whereby the dematching layer 102 and the piezoelectric element layer 101 are cut, and the plate-like piezoelectric element layer 101 becomes a rectangular parallelepiped.

[0073] Here, the thickness of the second surface 1222 of the dematching layer 102 is increased (step S12). This can be achieved by plating or sputtering the back surface of the laminate. As a result, a laminate similar to that shown in FIG. 7 is formed. The subsequent steps may be similar to those of the first embodiment, and therefore a description thereof will be omitted.

[0074] As in the second embodiment described above, the thickness of the second surface 1222 of the second member 122 may be increased after the layers are stacked. In this case, as in the first embodiment, it is possible to prevent the second member 122 from melting and being absorbed by the solder (being eaten by the solder), thereby preventing poor connection.

[0075] (Embodiment 3) Fig. 12 is a cross-sectional view of an ultrasonic vibrator according to embodiment 3. As shown in Fig. 12, in a dematching layer 102A of an ultrasonic vibrator 100A according to embodiment 3, an uneven surface is formed between a first member 121A and a second member 122A. Then, a wire 103 is electrically connected to a second surface 1222A of the second member 122A on which the uneven surface is formed.

[0076] Next, a method for manufacturing the ultrasonic vibrator 100A will be described. The method for manufacturing the ultrasonic vibrator according to the third embodiment is similar to the steps shown in FIG.

[0077] As shown in Fig. 5, members used to manufacture the ultrasonic vibrator 100A are prepared (step S1). Fig. 13 is a diagram showing the preparation of the members. As shown in Fig. 13, a piezoelectric element layer 101, a dematching layer 102A, a backing material 104, a first acoustic matching layer 105, and a second acoustic matching layer 106 are prepared. At this time, an uneven surface is formed between the first member 121A and the second member 122A of the dematching layer 102A. This can be achieved by plating the surface of the first member 121A, on which the uneven surface is formed, to form the second member 122A, and then plating the surface so that the recesses are filled.

[0078] Next, the piezoelectric element layer 101, the dematching layer 102A, the backing material 104, the first acoustic matching layer 105, and the second acoustic matching layer 106 are laminated using an adhesive or the like (step S2). Fig. 14 is a diagram showing how each component is laminated. As shown in Fig. 14, a laminate is formed in which the dematching layer 102A to the second acoustic matching layer 106 are laminated.

[0079] Thereafter, the laminate formed in step S2 is diced with a dicing saw (step S3), whereby the dematching layer 102A and the piezoelectric element layer 101 are cut, and the plate-like piezoelectric element layer 101 becomes a rectangular parallelepiped.

[0080] Then, wiring is attached to the ultrasonic transducer 100A (step S4). Fig. 15 is a diagram showing how the wires are connected. As shown in Fig. 15, the wires 103 are electrically connected to the second surface 1222A of the second member 122A by soldering.

[0081] Finally, with the first acoustic matching layer 105 and the second acoustic matching layer 106 curved in the arc shape shown in Fig. 3, the backing material 104 is filled on the side of the piezoelectric element layer 101 on which the dematching layer 102A is laminated (step S5). As a result, an ultrasonic probe having a plurality of ultrasonic transducers 100A is manufactured.

[0082] According to the third embodiment described above, when the wire 103 is electrically connected to the second surface 1222A of the second member 122A by soldering in step S4, an uneven surface is formed between the first member 121A and the second surface 1222A. As a result, the second member 122A can be prevented from melting and being absorbed by the solder (being eaten by the solder), and poor connection can be prevented.

[0083] (Embodiment 4) The configuration of an ultrasonic vibrator 100A according to embodiment 4 is the same as that of embodiment 3, and therefore description thereof will be omitted. Fig. 16 is a flowchart showing an outline of steps in a method for manufacturing an ultrasonic vibrator according to embodiment 4.

[0084] 16, the same processes as those in FIG. 9 are performed up to step S3, and then the dematching layer 102 and the piezoelectric element layer 101 are cut, as shown in FIG. 11, to form a laminate in which the dematching layer 102 to the second acoustic matching layer 106 are stacked. In this laminate, the first surface 1221, the second surface 1222, and the third surface 1223 of the second member 122 have the same thickness. Note that the thickness of each surface refers to the dimension of each surface in the direction perpendicular to each surface.

[0085] Next, a textured surface is formed between the first member 121A and the second member 122A of the dematching layer 102A (step S21). This can be achieved by forming a textured surface on the back side of the laminate by etching, laser irradiation, sandblasting, or the like, and then plating the recesses to fill them, or by attaching a highly conductive member to the back side. This results in a laminate similar to that shown in FIG. 14. The subsequent steps may be the same as those in embodiment 3, so a description thereof will be omitted.

[0086] As in the fourth embodiment described above, an uneven surface may be formed between the first member 121A and the second member 122A of the second member 122A after the layers are stacked. In this case, as in the third embodiment, it is possible to prevent the second member 122A from melting and being absorbed by the solder (being eaten by the solder), thereby preventing poor connection.

[0087] 17 is a cross-sectional view of an ultrasonic vibrator according to embodiment 5. As shown in Fig. 17, the dematching layer 102B of the ultrasonic vibrator 100B according to embodiment 4 has a first member 121B and a second member 122B laminated on the surface of the first member 121B opposite to the piezoelectric element layer 101.

[0088] The first member 121B and the second member 122B are made of the same material, but the second member 122B has a higher concentration of conductive material than the first member 121B, making it more conductive than the first member 121B. Specifically, the first member 121B and the second member 122B are formed, for example, by adding a conductive filler to tungsten carbide, but the second member 122B has a higher filler concentration than the first member 121B. The thickness of the second member 122B is thick enough to prevent it from being absorbed into the solder when connecting the wire 103. The thickness of the second member 122B is preferably no more than half the thickness of the dematching layer 102B, and more preferably no more than one-third the thickness. The thicknesses of the dematching layer 102B and the second member 122B refer to the respective dimensions in the direction in which the first member 121B and the second member 122B are aligned. In other words, the dimensions in the direction perpendicular to the surface to be soldered are the thickness of the dematching layer 102B and the thickness of the second member 122B.

[0089] Furthermore, in order to make the second member 122B have a higher concentration of conductive material than the first member 121B, for example, a portion of tungsten carbide may be formed with a higher binder concentration. That is, a portion of the tungsten carbide may be the second member 122B, and a portion with a relatively low binder concentration may be the first member 121B. Furthermore, the first member 121B and the second member 122B may be formed separately and then bonded together. That is, two pieces of tungsten carbide with different binder or filler concentrations may be formed and then bonded together.

[0090] Next, a method for manufacturing an ultrasonic vibrator will be described. The method for manufacturing an ultrasonic vibrator according to the fifth embodiment is similar to the steps shown in FIG.

[0091] As shown in Fig. 5, members used to manufacture the ultrasonic vibrator 100B are prepared (step S1). Fig. 18 is a diagram showing the preparation of the members. As shown in Fig. 18, a piezoelectric element layer 101, a dematching layer 102B, a backing material 104, a first acoustic matching layer 105, and a second acoustic matching layer 106 are prepared. The dematching layer 102B has a first member 121B and a second member 122B that has higher conductivity than the first member 121B.

[0092] Next, the piezoelectric element layer 101, the dematching layer 102B, the backing material 104, the first acoustic matching layer 105, and the second acoustic matching layer 106 are laminated using an adhesive or the like (step S2). Fig. 19 is a diagram showing how each component is laminated. As shown in Fig. 19, a laminate is formed in which the dematching layer 102B to the second acoustic matching layer 106 are laminated.

[0093] Thereafter, the laminate formed in step S2 is diced with a dicing saw (step S3), whereby the dematching layer 102B and the piezoelectric element layer 101 are cut, and the plate-like piezoelectric element layer 101 becomes a rectangular parallelepiped.

[0094] Then, wiring is attached to the ultrasonic transducer 100B (step S4). Fig. 20 is a diagram showing how the wires are connected. As shown in Fig. 20, the wires 103 are electrically connected to the second member 122B by soldering.

[0095] Finally, with the first acoustic matching layer 105 and the second acoustic matching layer 106 curved in the arc shape shown in Fig. 3, the backing material 104 is filled on the side of the piezoelectric element layer 101 on which the dematching layer 102B is laminated (step S5). As a result, an ultrasonic probe having a plurality of ultrasonic transducers 100B is manufactured.

[0096] According to the fifth embodiment described above, the thickness of the second member 122B is increased when the wire 103 is electrically connected to the second member 122B by soldering in step S4. As a result, the second member 122B can be prevented from melting and being absorbed by the solder (being eaten by the solder), thereby preventing poor connection.

[0097] Sixth Embodiment The configuration of an ultrasonic vibrator 100B according to a sixth embodiment is the same as that of the fifth embodiment, and therefore description thereof will be omitted. Fig. 21 is a flowchart showing an outline of steps in a method for manufacturing an ultrasonic vibrator according to the sixth embodiment.

[0098] As shown in Fig. 21, members used to manufacture the ultrasonic transducer 100B are prepared (step S11). Fig. 22 is a diagram showing how the members are prepared. As shown in Fig. 22, a piezoelectric element layer 101, a first member 121B, a backing material 104, a first acoustic matching layer 105, and a second acoustic matching layer 106 are prepared.

[0099] Next, the piezoelectric element layer 101, the first member 121B, the backing material 104, the first acoustic matching layer 105, and the second acoustic matching layer 106 are laminated using an adhesive or the like (step S2). Fig. 23 is a diagram showing how the various members are laminated. As shown in Fig. 23, a laminate is formed in which the first member 121B to the second acoustic matching layer 106 are laminated.

[0100] Thereafter, the laminate formed in step S2 is diced with a dicing saw (step S3), whereby the first member 121B and the piezoelectric element layer 101 are cut, and the plate-like piezoelectric element layer 101 becomes a rectangular parallelepiped.

[0101] Next, the second member 122B of the dematching layer 102B is formed (step S31). This can be achieved by plating, sputtering, impregnation, or attaching a highly conductive member to the back side of the laminate. This results in a laminate similar to that shown in FIG. 7. The subsequent steps may be similar to those of the first embodiment, so a description thereof will be omitted.

[0102] As in the sixth embodiment described above, the second member 122B may be formed after the layers are stacked. In this case, too, the second member 122B can be prevented from melting and being absorbed by the solder (being eaten by the solder), thereby preventing poor connection.

[0103] (Embodiment 7) Figure 24 is a cross-sectional view of an ultrasonic vibrator according to embodiment 7. As shown in Figure 24, a dematching layer 102C of an ultrasonic vibrator 100C according to embodiment 7 has a first member 121C and a second member 122C. The thickness of a third surface 1223C of the second member 122C is greater than the thickness of the first surface 1221 and the thickness of the second surface 1222C. A wire 103 is electrically connected to the third surface 1223C. The thickness of each surface refers to the dimension of each surface in a direction perpendicular to the surface.

[0104] According to the seventh embodiment described above, the thickness of the third surface 1223C is increased when the wire 103 is electrically connected to the third surface 1223C of the second member 122 by soldering. As a result, the second member 122C can be prevented from melting and being absorbed by the solder (being eaten by the solder), and poor connection can be prevented.

[0105] (Embodiment 8) Figure 25 is a cross-sectional view of an ultrasonic vibrator according to embodiment 8. As shown in Figure 25, in a dematching layer 102D of an ultrasonic vibrator 100D according to embodiment 8, an uneven surface is formed between a first member 121D and a second member 122D. The wire 103 is electrically connected to a third surface 1223D of the second member 122D on which the uneven surface is formed. The second surface 1222D has the same thickness as the first surface 1221. The thickness of each surface refers to the dimension of each surface in a direction perpendicular to the surface.

[0106] According to the eighth embodiment described above, when the wire 103 is electrically connected to the third surface 1223D of the second member 122D by soldering, an uneven surface is formed between the first member 121D and the third surface 1223D. As a result, the second member 122D can be prevented from melting and being absorbed by the solder (being eaten by the solder), and poor connection can be prevented.

[0107] 26 is a cross-sectional view of an ultrasonic transducer according to embodiment 9. As shown in Fig. 26, a dematching layer 102E of an ultrasonic transducer 100E according to embodiment 9 has a first member 121E and a second member 122E formed on a side surface of the first member 121E.

[0108] The first member 121E and the second member 122E are made of the same material, but the second member 122E has a higher concentration of conductive material than the first member 121E, making it more conductive than the first member 121E. The thickness of the second member 122E is thick enough to prevent it from being absorbed into the solder when connecting the wire 103. The thickness of the second member 122E is preferably less than half, and more preferably less than one-third, of the thickness of the dematching layer 102E. The thicknesses of the dematching layer 102E and the second member 122E refer to the respective dimensions in the direction in which the first member 121E and the second member 122E are aligned. In other words, the thicknesses of the dematching layer 102E and the second member 122E refer to the dimensions perpendicular to the surface to be soldered.

[0109] According to the ninth embodiment described above, when the wire 103 is electrically connected to the second member 122E by soldering, the thickness of the second member 122E is increased, which prevents the second member 122E from melting and being absorbed by the solder (being eaten by the solder), thereby preventing poor connection.

[0110] Up to this point, an ultrasonic endoscope has been described as a medical device, but it may also be, for example, an ultrasonic catheter.

[0111] Further advantages and modifications will readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0112] DESCRIPTION OF SYMBOLS 1 Endoscope system 2 Ultrasonic endoscope 3 Ultrasonic observation device 4 Endoscope observation device 5 Display device 6 Insertion section 7 Operation section 8 Universal cord 9 Endoscope connector 10 Ultrasonic probe 31 Ultrasonic cable 41 Video processor 42 Light source device 61 Rigid member 62 Bending section 63 Flexible tube 71 Bending knob 72 Operation member 73 Treatment tool insertion port 100, 100A, 100B, 100C, 100D, 100E Ultrasonic transducer 101 Piezoelectric element layer 102, 102A, 102B, 102C, 102D, 102E Dematching layer 103 Wire 104 Backing material 105 First acoustic matching layer 106 Second acoustic matching layer 121, 121A, 121B, 121C, 121D, 121E First member 122, 122A, 122B, 122C, 122D, 122E Second member 611 Illumination unit 612 Imaging unit 613 Treatment tool channel 1221 First surface 1222 Second surface 1223 Third surface

Claims

1. a piezoelectric element layer having piezoelectric elements for transmitting and receiving ultrasonic waves; a dematching layer laminated on the piezoelectric element layer and configured to reflect at least a portion of the ultrasonic wave, the dematching layer including a first member and a second member having a higher electrical conductivity than the first member; a wire electrically connected to the second member; Equipped with the second member has a first surface located between the piezoelectric element layer and the first member, and a connection surface that is different from the first surface, is formed to be thicker than the first surface, and is electrically connected to the first surface; The wire is an ultrasonic transducer electrically connected to the connection surface.

2. The ultrasonic transducer of claim 1 , wherein the wire is made of a material different from that of the second member.

3. The ultrasonic transducer according to claim 1 , wherein the wire is electrically connected to the second member by soldering.

4. 2. The ultrasonic transducer of claim 1, further comprising a backing material that contains the wire and absorbs or attenuates the ultrasonic waves.

5. The ultrasonic transducer according to claim 1 , wherein the first member is made of a material having a higher acoustic impedance than the second member.

6. An ultrasonic transducer as described in claim 1, wherein the connection surface is a second surface located on the opposite side of the first surface across the first member.

7. The ultrasonic transducer of claim 6 , wherein the thickness of the second surface is ⅓ or less of the thickness of the dematching layer.

8. An ultrasonic transducer as described in claim 1, wherein the connection surface is a third surface arranged to connect the first surface and a second surface located on the opposite side of the first surface across the first member.

9. 2. The ultrasonic transducer according to claim 1, wherein the first member includes at least one of tungsten (W), cobalt (Co), nickel (Ni), titanium (Ti), chromium (Cr), molybdenum (Mo), tantalum (Ta), and carbon (C).

10. 2. The ultrasonic transducer according to claim 1, wherein the second member includes at least one of gold (Au), silver (Ag), copper (Cu), cobalt (Co), nickel (Ni), titanium (Ti), chromium (Cr), molybdenum (Mo), tantalum (Ta), and carbon (C).

11. a piezoelectric element layer having piezoelectric elements for transmitting and receiving ultrasonic waves; a dematching layer laminated on the piezoelectric element layer and configured to reflect at least a portion of the ultrasonic wave, the dematching layer including a first member and a second member having a higher electrical conductivity than the first member; a wire electrically connected to the second member; Equipped with The first member has a recess. The second member has a protrusion that protrudes so as to enter the recess, The wire is an ultrasonic transducer electrically connected to the rear surface of the protrusion.

12. An ultrasonic transducer as described in claim 11, wherein the thickness of the second surface is less than 1 / 3 of the thickness of the dematching layer.

13. a piezoelectric element layer having piezoelectric elements for transmitting and receiving ultrasonic waves; a dematching layer laminated on the piezoelectric element layer and configured to reflect at least a portion of the ultrasonic wave, the dematching layer including a first member and a second member having a higher electrical conductivity than the first member; a wire electrically connected to the second member; Equipped with The first member and the second member are made of the same material, An ultrasonic transducer in which the concentration of the conductive material contained in the second member is higher than the concentration of the conductive material contained in the first member.

14. An ultrasonic transducer according to any one of claims 1, 11, and 13; an insertion section having the ultrasound transducer disposed at a tip thereof and to be inserted into a subject; A medical device comprising:

15. The medical device according to claim 14 , further comprising an imaging unit for imaging the inside of the subject.