JP2021019927A - Ultrasonic probe and ultrasonic detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a small ultrasonic probe having a matching circuit. An ultrasonic probe includes a cavity layer having a cavity, and a connection portion, a matching circuit, and an ultrasonic transducer located on the cavity layer, respectively. The connection part can be electrically connected to the transmission / reception part that transmits / receives an electric signal to / from the ultrasonic transducer, and is located in a state of being connected to the ultrasonic transducer via a matching circuit. There is. The ultrasonic transducer includes an ultrasonic transducer located above the cavity and having a first electrode and a second electrode. The matching circuit is a circuit for matching the impedance of the transmitter / receiver with the impedance of the ultrasonic transducer, and includes at least one of an inductor and a capacitor. [Selection diagram] Fig. 5

Description

The present disclosure relates to an ultrasonic probe and an ultrasonic detector.

An ultrasonic probe that sends ultrasonic waves to a subject and receives reflected waves from the subject is known.

As such an ultrasonic probe, one provided with an oscillator, a pulsar substrate, a receiver substrate, and a matching circuit substrate has been proposed (see, for example, the description in Patent Document 1 below). Here, the oscillator sends ultrasonic waves to the subject, receives reflected waves, converts them into electrical signals, and outputs them. Further, the pulsar substrate generates a drive pulse for the oscillator to send ultrasonic waves to the oscillator. Further, the receiver board amplifies the electric signal output by the oscillator. The pulsar board and the receiver board are electrically connected via a matching circuit board.

JP-A-2009-300233

There is room for improvement in terms of miniaturization of ultrasonic probes having matching circuits.

An ultrasonic probe and an ultrasonic detector are disclosed.

One aspect of the ultrasonic probe of the present disclosure includes a cavity layer having a cavity and a connection, a matching circuit and an ultrasonic transducer located above the cavity layer, respectively. A state in which the connection unit can electrically connect a transmission / reception unit that transmits / receives an electric signal to / from the ultrasonic transducer, and is connected to the ultrasonic transducer via the matching circuit. It is located at. The ultrasonic transducer includes an ultrasonic transducer located above the cavity and having a first electrode and a second electrode. The matching circuit is a circuit for matching the impedance of the transmission / reception unit with the impedance of the ultrasonic transducer, and includes at least one of an inductor and a capacitor.

One aspect of the ultrasonic detection device of the present disclosure includes the ultrasonic probe of the above-mentioned aspect and the transmission / reception unit located in a state of being electrically connected to the connection portion. There is.

For example, a small ultrasonic probe having a matching circuit can be realized.

FIG. 1 is a diagram showing an example of the configuration of the ultrasonic wave detection device according to the first embodiment. FIG. 2A is a diagram showing an example of a configuration including a tip portion of a catheter portion in the IIa portion of FIG. 1. FIG. 2B is a diagram showing an example of a virtual cut surface portion of the catheter portion along the line IIb-IIb of FIG. 2A. FIG. 3 is a diagram schematically showing an example of a circuit configuration of the ultrasonic wave detection device according to the first embodiment. FIG. 4 is a diagram showing an example of a circuit configuration of the ultrasonic probe according to the first embodiment. FIG. 5 is a plan view showing an example of the configuration of the ultrasonic probe according to the first embodiment. FIG. 6A is a diagram showing an example of a virtual cut surface portion of the ultrasonic probe along the VIa-VIa line of FIG. FIG. 6B is a diagram showing an example of a virtual cut surface portion of the ultrasonic probe along the VIb-VIb line of FIG. FIG. 6C is a diagram showing an example of a virtual cut surface portion of the ultrasonic probe along the VIc-VIc line of FIG. FIG. 6D is a diagram showing an example of a virtual cut surface portion of the ultrasonic probe along the Vid-Vid line of FIG. FIG. 7 is a flow chart showing an example of the manufacturing flow of the ultrasonic probe according to the first embodiment. FIG. 8A is a diagram showing an example of the circuit configuration of the ultrasonic probe according to the second embodiment. FIG. 8B is a diagram showing an example of the circuit configuration of the ultrasonic probe according to the third embodiment. FIG. 9 is a diagram showing an example of a virtual cut surface portion of the ultrasonic probe according to the fifth embodiment corresponding to the cut surface portion along the Vid-VId line of FIG. FIG. 10A is a plan view showing an example of the configuration of the second conductor layer in the ultrasonic probe according to the sixth embodiment. FIG. 10B is a diagram showing an example of a virtual cut surface portion of the ultrasonic probe along the line Xb-Xb of FIG. 10A.

An ultrasonic probe that sends ultrasonic waves to a subject and receives reflected waves from the subject is known.

As the ultrasonic probe, an ultrasonic probe in which a pulsar substrate and a receiver substrate are electrically connected to an oscillator via a matching circuit board can be considered. Here, the oscillator sends ultrasonic waves to the subject, receives reflected waves, converts them into electrical signals, and outputs them. The pulsar substrate generates a drive pulse for the oscillator to send ultrasonic waves. The receiver board amplifies the electrical signal output by the oscillator.

By the way, for example, there is known an ultrasonic detection device capable of performing an intravascular ultrasonic examination method (IVUS: Intravascular Ultrasound) that can view a tomographic image inside a blood vessel in real time by measuring the reflection of ultrasonic waves. .. In this ultrasonic detection device, generally, an ultrasonic probe and a pulsar receiver including a transmission / reception unit that transmits / receives a signal between the ultrasonic probe and the ultrasonic probe are electrically connected by a cable in a catheter. Has a configuration that In an ultrasonic detector, for example, a transducer in an ultrasonic probe generates ultrasonic waves in response to a pulsar receiver applying a drive transmission signal via a cable for signals in the catheter. Then, the transducer receives the ultrasonic waves reflected by each part of the blood vessel and generates a received signal. This received signal is sent to the pulsar receiver, for example, via a cable for the signal in the catheter.

In this IVUS-executable ultrasonic detector, for example, an ultrasonic matching circuit for matching the impedance of the pulsar receiver and the impedance of the transducer section is used for the purpose of improving the voltage of the received signal transmitted to the pulsar receiver. It is conceivable to install it on the probe. On the other hand, the ultrasonic probe is required to be miniaturized for insertion into a blood vessel, for example.

Such problems are not limited to ultrasonic detectors capable of performing IVUS, but small ultrasonic probes used in applications such as placing ultrasonic probes in tight spaces or confined spaces. It is common to all ultrasonic detection devices having.

Therefore, the present inventors have created a technique capable of miniaturizing an ultrasonic probe having a matching circuit.

Hereinafter, various embodiments will be described with reference to the drawings. In the drawings, parts having the same structure and function are designated by the same reference numerals, and duplicate description is omitted in the following description. The drawings are schematically shown. A right-handed XYZ coordinate system is attached to FIGS. 5 to 6 (d) and 9 to 10 (b). In this XYZ coordinate system, the direction of the thickness of the substrate Ss1 is the + Z direction. Further, in this XYZ coordinate system, the direction along one side of the base Ss1 is the + X direction, and the direction orthogonal to both the + X direction and the + Z direction is the + Y direction.

<1. First Embodiment>
The ultrasonic detection device 100 according to the first embodiment is an inspection device using a catheter for a living body including a human body. The ultrasonic wave detection device 100 according to the first embodiment will be described with reference to FIGS. 1 to 6 (d).

<1-1. Schematic configuration of ultrasonic detector>
As shown in FIG. 1, the ultrasonic detection device 100 includes, for example, a guide wire 1, a catheter unit 2, a cable unit 3, a main body control unit 4, and a drive mechanism 5.

The guide wire 1 is a linear member for guiding the catheter portion 2 to a desired place in a meandering and curved lumen of a tubular body as an object to be processed (also referred to as a subject) in a living body. .. Here, the tubular body may include, for example, meandering and curved blood vessels. Such blood vessels may include, for example, coronary arteries, blood vessels in the brain or blood vessels in the legs. If the tubular body is a blood vessel, the lumen is the lumen of the blood vessel.

The catheter unit 2 is a thin tubular medical device capable of performing various treatments on a tubular body as a subject. As shown in FIGS. 2A and 2B, the catheter portion 2 is located, for example, in the elongated tubular body 20 and the internal space (also referred to as a lumen) 2is of the tubular body 20. It has an elongated sensor unit 21 and.

The tubular body 20 has a hole 2th at the tip 2 tp, in which the guide wire 1 is inserted into the lumen 2is of the tubular body 20 with reference to the tip 1 tp of the guide wire 1. Further, the tubular body 20 has a hole 2op through which the guide wire 1 is inserted so as to be pulled out from the lumen 2is. Therefore, the tubular body 20 can be slid along the guide wire 1. Thereby, for example, the guide wire 1 can be inserted into the blood vessel, and the tubular body 20 can be inserted into the blood vessel along the guide wire 1. Then, for example, the sensor unit 21 can reach a target location such as a lesion along the tubular body 20.

The sensor unit 21 can move along the tubular body 20 in the longitudinal direction of the tubular body 20, for example, in the lumen 2is of the tubular body 20. Further, the sensor unit 21 has, for example, an ultrasonic probe 22 located in the vicinity of the tip portion 21 tp of the sensor unit 21, and a wiring unit W1. The ultrasonic probe 22 can transmit and receive ultrasonic waves to and from a tubular body as a subject, for example. Specifically, the ultrasonic probe 22 follows the longitudinal direction of the sensor unit 21, for example, in response to the electric signal s1 input from the main body control unit 4 via the cable unit 3 and the wiring unit W1. Ultrasonic waves can be sent in a direction intersecting the virtual axis (also referred to as a virtual axis) Ax2. As a result, the ultrasonic probe 22 can realize, for example, an operation (also referred to as wave transmission) of transmitting ultrasonic waves to a tubular body as a subject. Further, the ultrasonic probe 22 can receive, for example, an ultrasonic wave and convert the ultrasonic wave into an electric signal. For example, the ultrasonic probe 22 may be able to amplify an electric signal and then send it to the main body control unit 4 via the wiring unit W1.

The cable portion 3 is located, for example, in a state of being connected to the catheter portion 2 at the first end portion in the longitudinal direction. Further, the cable portion 3 has, for example, a connector 3c located at a second end portion in the longitudinal direction in a state of being detachably connected to the main body control unit 4. Therefore, for example, the main body control unit 4 can transmit and receive various signals to and from the catheter unit 2 via the cable unit 3. Further, the main body control unit 4 may supply electric power to the catheter unit 2 via, for example, the cable unit 3.

For example, the drive mechanism 5 can mechanically rotate the sensor unit 21 located in the cavity 2is of the tubular body 20 about the virtual axis Ax2 along the longitudinal direction of the sensor unit 21. Therefore, for example, the ultrasonic probe 22 can obtain an electric signal related to the tomographic structure at one location in the longitudinal direction of the tubular body as a subject for each rotation about the virtual axis Ax2. The method in which the ultrasonic probe 22 is rotated by mechanical rotation in this way is called a mechanical type.

The main body control unit 4 can control the operation of each part of the ultrasonic detection device 100, for example. The main body control unit 4 includes, for example, an input unit 41, an output unit 42, a transmission / reception unit 4p, and the like.

The input unit 41 can input a signal according to the operation of the user who uses the main body control unit 4, for example. The input unit 41 may include, for example, an operation unit, a microphone, various sensors, and the like. The operation unit may include a mouse, a keyboard, and the like capable of inputting signals according to the user's operation. The microphone can input a signal according to the user's voice. Various sensors can input signals according to the movement of the user.

The output unit 42 can output various information, for example. The output unit 42 may include, for example, a display unit and a speaker. The display unit can visually output various types of information in a manner recognizable by the user, for example. Here, the display unit may have the form of a touch panel integrated with at least a part of the input unit 41. The speaker can, for example, audibly output various types of information in a manner recognizable by the user. The various information output by the output unit 42 may include, for example, image information related to the tomographic structure of the tubular body as the subject, which is obtained by using the sensor unit 21.

The transmission / reception unit 4p can, for example, transmit / receive an electric signal to / from the ultrasonic probe 22 and apply a power supply voltage to the ultrasonic probe 22. The electrical signal transmitted / received between the transmission / reception unit 4p and the ultrasonic probe 22 may include, for example, a voltage signal and a current signal. The transmission / reception unit 4p is also referred to as, for example, a pulsar receiver. Further, the transmission / reception unit 4p has an internal resistance, and the internal resistance can detect a voltage corresponding to a current signal received from the ultrasonic probe 22. The electrical resistance of the internal resistance is set to a predetermined value of, for example, about 50Ω. The transmission / reception unit 4p amplifies the current signal and then amplifies the voltage generated by the internal resistance according to the amplified current signal or the internal resistance and then detects the voltage. You may have an amplifier for.

<1-2. Circuit configuration in ultrasonic detector>
As shown in FIG. 3, the ultrasonic detection device 100 includes a transmission / reception unit 4p and an ultrasonic probe 22. The wiring unit W1 is located in a state where the transmission / reception unit 4p and the ultrasonic probe 22 are electrically connected. Here, the wiring portion W1 is located in a state of being electrically connected to the connection portion (also referred to as the first connection portion) Cr1 of the ultrasonic probe 22. The first connection portion Cr1 is, for example, a portion capable of electrically connecting a transmission / reception unit 4p that transmits / receives an electric signal to / from the ultrasonic transducer Tr1.

As shown in FIG. 3, the wiring unit W1 includes the first f wiring W1f and the first s wiring W1s.

The first f wiring W1f is located, for example, in a state where the transmission / reception unit 4p and the ultrasonic probe 22 are electrically connected. Specifically, the first f wiring W1f is positioned in a state of being electrically connected to the first f connection portion Cr1f of the first connection portion Cr1 in the ultrasonic probe 22. In the first f wiring W1f, for example, a reference potential (also referred to as a reference potential) Vo can be applied to the ultrasonic probe 22 by the transmission / reception unit 4p. In the first embodiment, the reference potential Vo is set to, for example, + 10V, which is a predetermined positive potential. For example, a predetermined positive potential of about + 1V to + 30V may be applied to the reference potential Vo. From another point of view, the first f wiring W1f has a function as, for example, wiring (also referred to as a power supply line) for supplying power to the ultrasonic probe 22.

The first s wiring W1s is located, for example, in a state where the transmission / reception unit 4p and the ultrasonic probe 22 are electrically connected. Specifically, the first s wiring W1s is positioned in a state of being electrically connected to the first s connection portion Cr1s of the first connection portion Cr1 in the ultrasonic probe 22. The first s wiring W1s can execute, for example, transmission of an electric signal from the transmission / reception unit 4p to the ultrasonic probe 22 and transmission of an electric signal from the ultrasonic probe 22 to the transmission / reception unit 4p. it can.

As shown in FIG. 3, the ultrasonic probe 22 has, for example, a matching circuit Mc1 and an ultrasonic transducer Tr1.

The ultrasonic transducer Tr1 can, for example, execute a wave transmission that sends ultrasonic waves to a subject in response to the application of an electric signal from the transmission / reception unit 4p via the matching circuit Mc1. Further, the ultrasonic transducer Tr1 can receive, for example, an ultrasonic wave from a subject and convert the ultrasonic wave into an electric signal. For example, a transducer of the type using a piezoelectric element called pMUT (Piezo Micromachined Ultrasonic Transducer) is applied to the ultrasonic transducer Tr1.

The matching circuit Mc1 is located between the first connection portion Cr1 and the ultrasonic transducer Tr1. Therefore, the first connection portion Cr1 is located in a state of being electrically connected to the ultrasonic transducer Tr1 via the matching circuit Mc1. The matching circuit Mc1 is a circuit for matching (also referred to as impedance matching) between the impedance Zi of the transmission / reception unit 4p and the impedance Zl of the ultrasonic transducer Tr1. For example, in the matching circuit Mc1, the impedance Zi ^* of the ultrasonic transducer Tr1 seen from the transmission / reception unit 4p side is made a complex conjugate of the impedance Zi of the transmission / reception unit 4p. Further, for example, in the matching circuit Mc1, the impedance Zl ^* of the transmission / reception unit 4p seen from the ultrasonic transducer Tr1 side is a complex conjugate of the impedance Zl of the ultrasonic transducer Tr1. Due to such impedance matching, for example, in the transmission of an electric signal between the transmission / reception unit 4p and the ultrasonic transducer Tr1, energy loss is unlikely to occur, and the voltage of the electric signal is unlikely to decrease. Thereby, for example, the transmission / reception unit 4p can receive the electric signal from the ultrasonic transducer Tr1 at a higher voltage.

As shown in FIG. 4, the matching circuit Mc1 has, for example, an inductor L1 and a capacitor C1.

In the example of FIG. 4, the second f wiring W2f is in a state of electrically connecting the first f connecting portion Cr1f and the first electrode E1 of the ultrasonic transducer Tr1. The second s wiring W2s is in a state of electrically connecting the first s connection portion Cr1s and the second electrode E2 of the ultrasonic transducer Tr1. The inductor L1 is located in the middle of the path of the second wiring W2s. In other words, the inductor L1 is electrically connected in series with the ultrasonic transducer Tr1.

The inductor L1 and the ultrasonic transducer Tr1 are electrically connected to the capacitor C1 via the second connection portion Cr2 (the second connection portion Cr2s and the second f connection portion Cr2f). Specifically, the second s connection portion Cr2s located between the first s connection portion Cr1s of the second s wiring W2s and the inductor L1, the first f connection portion Cr1f of the second f wiring W2f, and ultrasonic waves. The capacitor C1 is located between the second f connection portion Cr2f located between the transducer Tr1 and the second f connection portion Cr2f. More specifically, the third electrode E3 of the capacitor C1 is electrically connected to the second f connection portion Cr2f, and the fourth electrode E4 of the capacitor C1 is electrically connected to the second s connection portion Cr2s. Is in a state of being. In other words, the capacitor C1 is electrically connected in parallel to the ultrasonic transducer Tr1.

If the configuration of the matching circuit Mc1 shown in FIG. 4 is adopted, for example, when the ultrasonic transducer Tr1 transmits and receives ultrasonic waves having a narrow band frequency of about 60 MHz (MHz), the transmission / reception unit 4p Impedance matching is realized between the impedance Zi and the impedance Zl of the ultrasonic transducer Tr1. Here, for example, depending on the magnitude relationship between the impedance Zi of the transmitter / receiver 4p and the impedance Zl of the ultrasonic transducer Tr1, the number of coil turns in the inductor L1 and the capacitance in the capacitor C1 are large by using a Smith chart or the like. Can be set.

<1-3. Structure of ultrasonic probe ＞
As shown in FIGS. 5 to 6 (d), the ultrasonic probe 22 has, for example, a substrate Ss1, an ultrasonic transducer Tr1, a first connection portion Cr1, and a matching circuit Mc1. Further, the ultrasonic probe 22 has, for example, an insulating layer Il4.

The substrate Ss1 is a layer having a cavity Cv1 (also referred to as a cavity layer). The substrate Ss1 has, for example, a shape in which the recesses constituting the cavity Cv1 are open to the upper surface (the surface on the vibration layer Se1 side). For the cavity Cv1 shape, for example, a shape having a circular cross section along the XY plane is applied. The shape of the cross section of the cavity Cv1 along the XY plane may be constant in the depth direction of the cavity Cv1, or the diameter may be larger toward the opening side (vibration layer Se1 side) of the recess. Any material can be applied to the material of the substrate Ss1. The substrate Ss1 may be integrally formed, or may be formed by combining a plurality of members. For example, an insulating material and a semiconductor material are applied to the material of the substrate Ss1. In other words, the substrate Ss1 as the cavity layer may be either a semiconductor material layer (also referred to as a semiconductor layer) or an insulating material (also referred to as an insulator layer). The insulating material may be an inorganic material or an organic material. For example, silicon (Si) or the like is applied as the semiconductor material. In this case, for example, as shown in FIGS. 6A to 6D, portions of the substrate Ss1 along the lower surface facing the −Z direction (also referred to as insulating portions) in the Il1 and + Z directions. The portion (also referred to as an insulating portion) Il2 along the upper surface facing the surface is composed of an insulating material such as silicon dioxide (SiO ₂ ).

The ultrasonic transducer Tr1 has, for example, an ultrasonic transducer UV1. In the example of FIGS. 5 to 6 (d), the ultrasonic transducer Tr1 includes a plurality of ultrasonic transducers UV1 each having a pMUT configuration. The plurality of ultrasonic oscillators UV1 have a configuration in which four rows of ultrasonic oscillator trains Li1 having four ultrasonic oscillators UV1 arranged along the + X direction are arranged in the + Y direction. From another point of view, in the plurality of ultrasonic oscillators UV1, four rows of ultrasonic oscillator trains Co1 having four ultrasonic oscillators UV1 arranged along the + Y direction are arranged in the + X direction. Has a configuration. In other words, the ultrasonic transducer Tr1 has 16 ultrasonic transducers UV1. Each of the plurality of ultrasonic vibrators UV1 is layered with the layered first electrode E1 and the piezoelectric body portion D1 which are sequentially laminated on the vibrating layer Se1 which is located in a state of being bonded to the upper surface of the substrate Ss1. It has a second electrode E2. In other words, each ultrasonic vibrator UV1 has a laminate in which the first electrode E1, the piezoelectric portion D1 and the second electrode E2 are laminated in the order described above on the vibrating layer Se1. Further, each laminated body is located on the opposite side of the vibrating layer Se1 from the cavity Cv1. Therefore, each ultrasonic oscillator UV1 is located on the cavity Cv1 and has a first electrode E1 and a second electrode E2. In the first embodiment, each ultrasonic vibrator UV1 is a portion between the laminated body of the first electrode E1, the piezoelectric body portion D1 and the second electrode E2, and the laminated body of the vibrating layer Se1 and the cavity Cv1. And, including.

The vibrating layer Se1 is, for example, a layer having a width over a plurality of ultrasonic vibrators UV1 and having a substantially constant thickness. The vibrating layer Se1 regulates, for example, deformation of the piezoelectric body portion D1 in the plane direction, and contributes to causing out-of-plane vibration. The vibrating layer Se1 is located in a state of being supported by a portion around the cavity Cv1 in the upper surface of the substrate Ss1 facing the + Z direction. In other words, the vibrating layer Se1 is located so as to cover the upper surface of the substrate Ss1 so as to close the openings of the plurality of cavities Cv1. As a result, the vibrating layer Se1 can easily vibrate in the portion constituting each ultrasonic vibrator UV1. For example, an insulating material or a semiconductor material is applied to the vibrating layer Se1. The insulating material may be an inorganic material or an organic material. For example, silicon or the like is applied to the semiconductor material. In this case, for example, as shown in FIGS. 6A to 6D, the portions (also referred to as insulating portions) Il3 of the vibrating layer Se1 along the upper surface facing the + Z direction are respectively. It is composed of an insulating material such as silicon dioxide (SiO ₂ ). The vibrating layer Se1 may be a laminated body in which a plurality of layers made of different materials are laminated. The vibrating layer Se1 may be made of, for example, silicon nitride.

The first electrode E1 is located in a state of being connected to the first f connection portion Cr1f by the second f wiring W2f. Here, the second f wiring W2f common to the plurality of first electrodes E1 is connected. As a result, the same potential can be applied to the plurality of first electrodes E1. In the example of FIGS. 5 to 6 (d), four first electrodes E1 are electrically connected in series by the second f wiring W2f for each ultrasonic oscillator row Co1. The connection mode of the plurality of first electrodes E1 by the second f wiring W2f is not limited to this, and various connection modes may be appropriately adopted. The first electrode E1 and the second f wiring W2f are included in, for example, the first conductor layer Cl1 located on the vibrating layer Se1. Each of the first electrode E1 and the second f wiring W2f is integrally made of the same material, for example, and has the same thickness. The first electrode E1 and the second f wiring W2f may be made of different materials or may have different thicknesses. The planar shape and size of the first electrode E1 are substantially the same as, for example, the planar shape and size of the opening of the cavity Cv1. When viewed in a plane in the −Z direction, the first electrode E1 is in a state where, for example, most (for example, 80% or more) or the whole of the first electrode E1 overlaps the cavity Cv1. When viewed in a plane in the −Z direction, the outer edge of the first electrode E1 may be located inside, coincide with, or outside the outer edge of the opening of the cavity Cv1, for example. It may be located. A conductor such as a metal material is applied to the material of the first conductor layer Cl1. Metallic materials include, for example, gold (Au), platinum (Pt), aluminum (Al), copper (Cu) or chromium (Cr) or alloys thereof. The first conductor layer Cl1 may be a stack of a plurality of conductor layers each composed of different metal materials.

The plurality of piezoelectric parts D1 are located in a state of being separated from each other among the plurality of ultrasonic vibrators UV1. The planar shape and size of the piezoelectric portion D1 are substantially the same as, for example, the planar shape and size of the opening of the cavity Cv1 and the first electrode E1. Then, when viewed in a plane in the −Z direction, for example, most (for example, 80% or more) or the entire piezoelectric body portion D1 is in a state of overlapping the opening of the cavity Cv1 and the first electrode E1. When viewed in a plane in the −Z direction, the outer edge of the piezoelectric body portion D1 may be located inside or coincide with, for example, the opening of the cavity Cv1 and the outer edge of the first electrode E1. It may be located on the outside.

The thickness of the plurality of piezoelectric parts D1 is substantially constant. The thickness of the piezoelectric body portion D1 may be appropriately set. For example, the thickness of the piezoelectric portion D1 is made larger than the thickness of each of the first electrode E1 and the second electrode E2. Here, the thickness of the piezoelectric body portion D1 is, for example, about 0.5 micrometer (μm) to about 10 μm. The thickness of each of the first electrode E1 and the second electrode E2 is set to, for example, less than half the thickness of the piezoelectric portion D1.

The piezoelectric body portion D1 may be composed of a single crystal piezoelectric body or a polycrystalline piezoelectric body. Examples of the material of the piezoelectric part D1 include aluminum nitride (AlN), zinc oxide (ZnO), barium titanate (BTO: BaTIO ₃ ), sodium potassium niobate (KNN: (K, Na) NbO ₃ ), and titanium. Piezoelectric materials such as sodium bismuth acid (NBT: Na _0.5 Bi _0.5 TiO ₃ ) or lead zirconate titanate (PZT: Pb (Zr _x , Ti _1-x ) O ₃ ) can be applied. Further, the material of the piezoelectric body portion D1 may be, for example, a material obtained by adding scandium (Sc) to the above-mentioned piezoelectric material. Thereby, for example, the piezoelectric effect in the piezoelectric material can be improved. Here, the piezoelectric body may or may not be a ferroelectric substance, and may or may not be a pyroelectric body. Further, as the piezoelectric material, a material having an appropriate crystal structure such as a perovskite type or a wurtzite type can be applied. In the piezoelectric body portion D1, for example, the polarization axis direction (single crystal electric axis) is the thickness direction of the piezoelectric body portion D1 (the direction in which the first electrode E1, the piezoelectric body portion D1 and the second electrode E2 are laminated. ) Is included. For example, in the piezoelectric body portion D1, the polarization axis direction is the thickness direction as a whole. The piezoelectric body portion D1 may be formed directly on the first electrode E1 or may be formed on the first electrode E1 via a buffer layer for improving the adhesion with the first electrode E1. Good. For example, strontium ruthenate (SrRuO ₃ , also referred to as SRO) or the like can be applied to the buffer layer.

The second electrode E2 is located in a state of being connected to the first s connection portion Cr1s by the second s wiring W2s. Here, the common second s wiring W2s is connected to the plurality of second electrodes E2. As a result, the same potential can be applied to the plurality of second electrodes E2. In the example of FIGS. 5 to 6 (d), the four second electrodes E2 are electrically connected by the second wiring W2s for each ultrasonic oscillator train Li1 including the four ultrasonic transducers Tr1 arranged along the + X direction. It is in a state of being connected in series. The connection mode of the plurality of second electrodes E2 by the second s wiring W2s is not limited to this, and various connection modes may be appropriately adopted. The second electrode E2 and the second wiring W2s are contained in, for example, the second conductor layer Cl2. Here, the insulating layer Il4 is located so as not to cause a short circuit between the second electrode E2 and the second wiring W2s and the first conductor layer Cl1, for example, so as to cover most of the first conductor layer Cl1. There is. An insulating material such as silicon dioxide or silicon nitride is applied to the material of the insulating layer Il4. The thickness of the insulating layer Il4 is, for example, about 0.1 μm to 1 μm. However, the second electrode E2 is positioned so as to be in contact with the piezoelectric portion D1 at the opening (also referred to as the first opening) O1 of the insulating layer Il4 on the piezoelectric portion D1.

Each of the second electrode E2 and the second wiring W2s is integrally made of the same material, for example, and has the same thickness. The second electrode E2 and the second wiring W2s may be made of different materials or may have different thicknesses. The planar shape and size of the second electrode E2 are substantially the same as, for example, the planar shape and size of the piezoelectric body portion D1. When viewed in a plane in the −Z direction, the second electrode E2 is in a state where, for example, most (for example, 80% or more) or the whole of the second electrode E2 overlaps the piezoelectric body portion D1. When viewed in a plane in the −Z direction, the outer edge of the second electrode E2 may be located inside, coincide with, or be outside the outer edge of the piezoelectric body portion D1, for example. It may be located. A conductor such as a metal material is applied to the material of the second conductor layer Cl2. Metallic materials include, for example, gold, platinum, aluminum, copper or chromium or alloys thereof. The second conductor layer Cl2 may be a stack of a plurality of conductor layers each composed of different metal materials.

The first connecting portion Cr1 is located on the substrate Ss1 as a cavity layer. The first connection portion Cr1 includes, for example, a first f connection portion Cr1f for connecting the first f wiring W1f and a first s connection portion Cr1s for connecting the first s wiring W1s. For example, metal electrode pads located apart from each other are applied to the first f connection portion Cr1f and the first s connection portion Cr1s. As the shape of the electrode pad, for example, a rectangular shape in a plan view in the −Z direction is applied. The first f connection portion Cr1f is in a state of being electrically connected to the second f wiring W2f. Specifically, the first f connection portion Cr1f is positioned so as to be laminated on the first end portion of the second f wiring W2f. The first s connection portion Cr1s is located in a state of being connected to the first end portion of the second s wiring W2s. The first f connection portion Cr1f and the first s connection portion Cr1s are contained in, for example, the second conductor layer Cl2. Here, for example, a configuration in which the first f connection portion Cr1f is included in the first conductor layer Cl1 may be adopted.

The matching circuit Mc1 is located on the substrate Ss1 as a cavity layer. The matching circuit Mc1 has an inductor L1 and a capacitor C1 as described above. In this way, for example, if a configuration in which the matching circuit Mc1 is located in addition to the ultrasonic transducer Tr1 on the substrate Ss1 as one cavity layer is adopted, the ultrasonic transducer Tr1 and the matching circuit Mc1 can be used. A one-chip ultrasonic transducer 22 including the one can be realized. Therefore, it is possible to realize a small ultrasonic probe 22 having a matching circuit Mc1.

The inductor L1 may be composed of, for example, the second wiring W2s. In this case, the second s wiring W2s, which is located in a state where the first s connection portion Cr1s and the second electrode E2 are electrically connected, is integrally made of the same material as the inductor L1. .. If such a configuration is adopted, for example, the inductor L1 can be formed when forming the second s wiring W2s, and the inductor L1 can be easily formed. Here, in the example of FIGS. 5 to 6D, the inductor L1 surrounds the ultrasonic transducer Tr1 when the ultrasonic transducer Tr1, the matching circuit Mc1 and the substrate Ss1 are viewed in a plane in the −Z direction. Is located in. Specifically, for example, the inductor L1 can be configured by locating the second s wiring W2s in a spiral shape so as to rotate around the ultrasonic transducer Tr1 a plurality of times. If such a configuration is adopted, the ultrasonic transducer Tr1 and the inductor L1 are arranged on the substrate Ss1 as a cavity layer when the substrate Ss1, the ultrasonic transducer Tr1 and the inductor L1 are viewed in a plane in the −Z direction. The area required for this can be reduced. In other words, the inductor L1 can be efficiently arranged on the substrate Ss1 as the cavity layer. As a result, the ultrasonic probe 22 having the matching circuit Mc1 can be miniaturized.

The capacitor C1 includes, for example, a dielectric portion D2 and a third electrode E3 and a fourth electrode E4 located so as to sandwich the dielectric portion D2.

The third electrode E3 is located, for example, on the insulating portion Il3 of the vibrating layer Se1. Specifically, for example, the third electrode E3 is located on the insulating portion Il3 so as to be in contact with the insulating portion Il3. The third electrode E3 is, for example, in a state of being electrically connected to the second f connection portion Sr2f of the second f wiring W2f. The third electrode E3 is made of, for example, a conductive material. The third electrode E3 may be contained in, for example, the first conductor layer Cl1. In this case, for example, if the first electrode E1 and the third electrode E3 are integrally formed of the same material, the first electrode E1 and the third electrode E3 are formed at the same time. This makes it possible to easily form the capacitor C1. Further, the third electrode E3 is integrally formed of the same material as the first electrode E1 and the second f wiring W2f, and may have the same thickness. Thereby, the capacitor C1 can be easily formed. The first electrode E1, the second f wiring W2f, and the third electrode E3 may be made of different materials or may have different thicknesses. When viewed in a plane in the −Z direction, the plane shape of the third electrode E3 is, for example, a rectangular shape.

The dielectric portion D2 is located, for example, in a state of being sandwiched between the third electrode E3 and the fourth electrode E4. Specifically, for example, the dielectric portion D2 is located on the third electrode E3 so as to be in contact with the third electrode E3. The planar shape and size of the dielectric portion D2 are substantially the same as, for example, the planar shape and size of the third electrode E3. Then, when the dielectric portion D2 is viewed in a plane in the −Z direction, for example, the entire dielectric portion D2 is in a state of overlapping the third electrode E3. When viewed in a plane in the −Z direction, the outer edge of the dielectric portion D2 may be located inside, coincide with, or outside the outer edge of the third electrode E3. You may be. The thickness of the dielectric portion D2 is made substantially constant. The thickness of the dielectric portion D2 may be appropriately set. For example, the thickness of the dielectric portion D2 is made larger than the thickness of each of the third electrode E3 and the fourth electrode E4. Here, the thickness of the dielectric portion D2 is, for example, about 0.5 μm to 10 μm. The thickness of each of the third electrode E3 and the fourth electrode E4 is set to, for example, less than half the thickness of the dielectric portion D2. The dielectric portion D2 may be composed of a single crystal dielectric or a polycrystalline dielectric. As the material of the dielectric portion D2, for example, a dielectric material having the same piezoelectric effect as the material of the piezoelectric portion D1 may be applied. For example, if the material of the piezoelectric portion D1 and the material of the dielectric portion D2 are the same, the dielectric portion D2 can be formed when the piezoelectric portion D1 is formed. Thereby, the capacitor C1 can be easily formed. Further, for example, when the piezoelectric portion D1 and the dielectric portion D2 are simultaneously formed of the same material and with the same thickness, a correlation occurs between the characteristics of the ultrasonic oscillator UV1 and the characteristics of the capacitor C1 and matching is performed. Impedance matching by the circuit Mc1 can be performed properly. Further, here, for example, if PZT having a high dielectric constant is adopted as a material for the dielectric portion D2 and the piezoelectric portion D1, the capacitor C1 can be miniaturized. As a result, the ultrasonic probe 22 having the matching circuit Mc1 can be miniaturized.

The fourth electrode E4 is located, for example, on the dielectric portion D2. Specifically, the fourth electrode E4 is positioned so as to be in contact with the dielectric portion D2 at the opening (also referred to as the second opening) O2 of the insulating layer Il4 on the dielectric portion D2. The fourth electrode E4 is, for example, in a state of being electrically connected to the second s connection portion Sr2s of the second s wiring W2s. The fourth electrode E4 is made of, for example, a conductive material. The fourth electrode E4 may be contained in, for example, the second conductor layer Cl2. In this case, for example, if the second electrode E2 and the fourth electrode E4 are integrally formed of the same material, the second electrode E2 and the fourth electrode E4 are formed at the same time. This makes it possible to easily form the capacitor C1. Further, for example, the fourth electrode E4 may be integrally formed of the same material as the second electrode E2 and the second s wiring W2s, and may have the same thickness. Thereby, the capacitor C1 can be easily formed. The second electrode E2, the second s wiring W2s, and the fourth electrode E4 may be made of different materials or may have different thicknesses. The planar shape and size of the fourth electrode E4 are substantially the same as, for example, the planar shape and size of the dielectric portion D2. Then, when the fourth electrode E4 is viewed through the plane in the −Z direction, for example, most (for example, 80% or more) or the entire portion of the fourth electrode E4 is in a state of overlapping the dielectric portion D2. When viewed in a plane in the −Z direction, the outer edge of the fourth electrode E4 may be located inside, coincide with, or outside the outer edge of the dielectric portion D2. You may be.

<1-4. Operation of ultrasonic transducer>
The portions of the vibrating layer Se1, the first conductor layer Cl1, the plurality of piezoelectric parts D1 and the second conductor layer Cl2 located above the plurality of cavities Cv1 are vibrated to transmit ultrasonic waves and to transmit ultrasonic waves. It is a vibrating unit Vp1 that directly bears the wave reception. The thickness of the vibrating portion Vp1 is set to, for example, about several μm to several tens of μm. The operation of the vibrating unit Vp1 is, for example, as follows.

When an electric field is applied to the piezoelectric body portion D1 by the first electrode E1 and the second electrode E2 in the same direction as the polarization direction (one side in the Z-axis direction), the piezoelectric body portion D1 is moved in the plane direction (X-axis direction). And contracts in the Y-axis direction). Since this contraction is regulated by the vibrating layer Se1, the vibrating portion Vp1 is displaced so as to bend toward the cavity Cv1 side (−Z direction) like a bimetal. On the contrary, when an electric field is applied to the piezoelectric body portion D1 in the direction opposite to the direction of polarization, the vibrating portion Vp1 is displaced so as to bend in the direction opposite to the cavity Cv1 (+ Z direction).

Due to the displacement of the vibrating portion Vp1 as described above, a pressure wave is formed in the medium (for example, a fluid) around the vibrating portion Vp1. Then, when an electric signal whose voltage changes with a predetermined waveform is input to the first electrode E1 and the second electrode E2, an ultrasonic wave reflecting the waveform (for example, frequency) of the electric signal is generated.

The vibrating portion Vp1 is, for example, vibration (out-of-plane vibration, bending vibration) in the direction (Z-axis direction) facing the vibrating portion Vp1 as described above, and the center of the plan view becomes the antinode of the vibration and the outer edge vibrates. The resonance frequency is configured to be located in the frequency band of the ultrasonic wave with respect to the vibration of the primary mode which is the node of.

The electric signal is, for example, a voltage application that displaces the vibrating portion Vp1 toward the cavity Cv1 side (-Z direction) and a voltage application that displaces the vibrating portion Vp1 toward the opposite side (+ Z direction) of the cavity Cv1. It may be there. That is, the electrical signal may have its polarity (positive or negative) inverted. In other words, the electrical signal may be one in which the directions of voltage and electric field alternate in the Z-axis direction. Further, for example, in the electric signal, only the voltage application that displaces the vibrating portion Vp1 toward the cavity Cv1 side (−Z direction) or the voltage application that displaces the vibrating portion Vp1 toward the cavity Cv1 side (+ Z direction) is repeated. It may be the one that is used. In this case as well, ultrasonic waves are generated by repeating bending and elimination of bending by the restoring force.

Moreover, the waveform of the electric signal may be appropriate. For example, in one ultrasonic signal (echo signal), the number of waves may be appropriately set. Also, for example, the frequency and voltage may or may not be constant. Further, for example, when the polarity of the electric signal changes, the voltage on the positive side and the voltage on the negative side may have the same magnitude or may be different.

In the above, the transmission of ultrasonic waves has been described, but the reception of ultrasonic waves is realized by the principle opposite to that at the time of transmission of ultrasonic waves. The ultrasonic transducer Tr1 intermittently transmits ultrasonic waves, and receives ultrasonic waves while the ultrasonic waves are not being transmitted. As a result, the ultrasonic transducer Tr1 can receive, for example, the ultrasonic waves transmitted by itself and returned by the reflection in the subject.

<1-5. Ultrasonic probe manufacturing process>
For example, the ultrasonic probe 22 can be manufactured by performing the operations of steps Sp1 to Sp12 in FIG. 7 in the order described.

First, in step Sp1, a cavity Cv1 is formed on the upper surface of the substrate Ss1. Here, for example, a silicon substrate, which is a kind of semiconductor substrate, is used as the substrate Ss1. Cavity Cv1 can be formed by, for example, deep reactive ion etching (Deep-RIE (Reactive Ion Etching)). The depth of the cavity Cv1 is, for example, about 2.5 μm to 5 μm, and the diameter of the cross section of the cavity Cv1 along the XY plane is about 16 μm to 18 μm. The number and position of the cavity Cv1 are adjusted to the design of the number and position of the ultrasonic oscillator UV1.

In step Sp2, the oxide film (SiO _{2 and the} like) existing on the surface of the substrate Ss1 is removed by wet etching. For wet etching, for example, an aqueous solution using hydrofluoric acid is used.

In step Sp3, the substrate Ss1 is heated by the heat treatment furnace to form a thermal oxide film on the surface of the substrate Ss1. As a result, the portion along the lower surface of the substrate Ss1 becomes the insulating portion Il1, and the portion along the upper surface of the substrate Ss1 becomes the insulating portion Il2.

In step Sp4, the substrate is joined to the upper surface on which the cavity Cv1 of the substrate Ss1 is formed. As the substrate, for example, a semiconductor substrate such as a silicon substrate is used. Here, for example, the substrate can be sufficiently bonded to the upper surface of the substrate Ss1 by bonding the substrate to the upper surface of the substrate Ss1 at room temperature and then annealing at a low temperature of 200 ° C. to 300 ° C. As a result, the vibration layer Se1 is formed. Further, the substrate Ss1 can be regarded as a cavity layer having a cavity Cv1.

In step Sp5, the thickness of the vibrating layer Se1 is adjusted. Here, for example, the upper surface of the vibrating layer Se1 bonded on the substrate Ss1 is polished to reduce the thickness of the vibrating layer Se1 to a desired thickness. Here, what the vibration layer Se1 is bonded to on the substrate Ss1 is also referred to as silicon (SOI: Silicon On Insulator) on the insulating layer with a cavity.

In step Sp6, by heating the SOI with a cavity, a thermal oxide film is formed on the portion along the upper surface of the vibration layer Se1. Here, by heating the SOI with a cavity in a heat treatment furnace, a thermal oxide film having a thickness of about 0.5 μm can be formed on a portion along the upper surface of the vibrating layer Se1. As a result, the portion along the upper surface of the vibrating layer Se1 becomes the insulating portion Il3.

In step Sp7, on the vibrating layer Se1, the layer of the first conductor which is the source of the first conductor layer Cl1 and the layer of the piezoelectric material which is the source of the piezoelectric part D1 and the dielectric part D2 are sequentially arranged. Form. Here, for example, a layer of the first conductor and a layer of the piezoelectric body can be formed by using a sputtering method, a sol-gel method, or the like. For example, metal or the like is applied to the conductor. For example, PZT or the like is applied to the piezoelectric body. At this time, for example, by forming a thin film of Ti having a thickness of about 0.005 μm and then forming a thin film of platinum having a thickness of about 0.2 μm on the thin film of Ti, the first conductor Layers can be formed. Further, for example, after forming a thin film of a buffer layer having a thickness of about 0.05 μm on the layer of the first conductor, a piezoelectric material having a thickness of about 0.5 μm to 5 μm is formed on the thin film of the buffer layer. Form a layer of. Here, for example, an SRO layer is formed as a buffer layer, and a PZT layer is formed as a piezoelectric layer.

In step Sp8, patterning is performed on the piezoelectric layer formed in step Sp7. Here, for example, dry etching such as reactive ion etching (RIE) is used to pattern the layer of the piezoelectric material. Thereby, for example, the piezoelectric portion D1 and the dielectric portion D2 can be formed at the same time. Here, instead of the dry etching step, for example, a wet etching step of forming a resist film, etching using an acid solution, and peeling the resist may be performed.

In step Sp9, patterning is performed on the layer of the first conductor formed in step Sp7. Here, dry etching or wet etching is used to pattern the layer of the first conductor. As a result, the first conductor layer Cl1 including the first electrode E1, the third electrode E3, and the second f wiring W2f can be formed.

In step Sp10, a layer of an insulator such as silicon dioxide is formed on substantially the entire upper surface of the vibrating layer Se1 so as to cover the first conductor layer Cl1, the piezoelectric portion D1 and the dielectric portion D2. Here, for example, a layer of an insulator can be formed by TEOS (Tetraethoxysilane) -chemical vapor deposition (CVD). The thickness of the insulator layer is about 0.3 μm. Here, for example, silicon nitride and silicon oxynitride (SiNO) may be applied to the insulator.

In step Sp11, the first opening O1 and the second opening O2 are formed in the layer of the insulator formed in step Sp10. Here, for example, the first opening O1 is formed in the portion of the insulator layer on the piezoelectric portion D1 by dry etching or the like, and the portion of the insulator layer on the dielectric portion D2 is formed. The second opening O2 can be formed in. As a result, the insulating layer Il4 is formed.

In step Sp12, the second conductor layer Cl2 is formed. Here, for example, the second conductor layer Cl2 can be formed by forming a resist film as a mask, forming a film by vapor deposition of a conductive material, peeling the resist film, and the like. At this time, for example, after forming a thin film of Ti having a thickness of about 0.01 μm, a thin film of Au having a thickness of about 0.6 μm is formed on the thin film of Ti to form a second conductor layer. A layer of Cl2 can be formed. The second conductor layer Cl2 includes, for example, a second electrode E2 on the piezoelectric portion D1 and a fourth electrode E4 on the dielectric portion D2. Further, here, for example, the second conductor layer Cl2 may be formed by using the lift-off method, or the second conductor layer Cl2 may be formed by patterning after the film formation by sputtering or vapor deposition of the conductive material. ..

<1-6. Summary of the first embodiment>
As described above, the ultrasonic probe 22 according to the first embodiment has, for example, an ultrasonic transducer Tr1 and a matching circuit Mc1 located on the substrate Ss1 as one cavity layer. In other words, in addition to the ultrasonic transducer Tr1, the matching circuit Mc1 is also located on the substrate Ss1 as one cavity layer. Thereby, for example, a one-chip ultrasonic probe 22 including the ultrasonic transducer Tr1 and the matching circuit Mc1 can be realized. As a result, a small ultrasonic probe 22 having a matching circuit Mc1 can be realized. Further, here, for example, by impedance matching by the matching circuit Mc1, the transmission / reception unit 4p can receive the electric signal from the ultrasonic transducer Tr1 at a higher voltage.

Then, for example, if the ultrasonic detection device 100 having such a small ultrasonic probe 22 and the transmission / reception unit 4p is adopted, the ultrasonic probe 22 is arranged in a narrow space or a limited place. An ultrasonic detection device 100 used in such applications is realized.

Further, for example, if the material of the piezoelectric portion D1 of the ultrasonic transducer Tr1 and the material of the dielectric portion D2 of the capacitor C1 in the matching circuit Mc1 are the same, the piezoelectric portion D1 and the dielectric portion D2 are the same. It can be formed at the same time in the process. Thereby, for example, the capacitor C1 can be easily formed without adding a step for forming the capacitor C1.

<2. Other embodiments>
The present disclosure is not limited to the above-described first embodiment, and various changes and improvements can be made without departing from the gist of the present disclosure.

<2-1. Second Embodiment>
In the first embodiment, for example, the matching circuit Mc1 may be changed to the matching circuit Mc1A according to the second embodiment having a configuration different from that of the matching circuit Mc1. The matching circuit Mc1A is, for example, with respect to the inductor L1 located in a state of being electrically connected in parallel to the ultrasonic transducer Tr1 and the ultrasonic transducer Tr1 as shown in FIG. 8A. It has a capacitor C1 which is located in a state of being electrically connected in series. Here, the ultrasonic transducer Tr1 is electrically connected to the capacitor C1 and the inductor L1 via the third connection portion Cr3 (third connection portion Cr3s and third f connection portion Cr3f). Specifically, the third s connection portion Cr3s located between the capacitor C1 in the second s wiring W2s and the ultrasonic transducer Tr1, and the first f connection portion Cr1f and the ultrasonic transducer in the second f wiring W2f. The inductor L1 is located between the third f connection portion Cr3f located between the Tr1 and the inductor L1. More specifically, the first end of the inductor L1 is connected to the third f connection portion Cr3f of the second f wiring W2f, and the second end of the inductor L1 is connected to the third s connection portion Cr3s of the second s wiring W2s. It is located in the state of being. Further, the third electrode E3 of the capacitor C1 is electrically connected to the first s connection portion Cr1s by the second s wiring W2s, and the fourth electrode E4 of the capacitor C1 is electrically connected to the third s connection portion Cr3s. It is located in the state of being. In this case, for example, when the ultrasonic transducer Tr1 transmits and receives ultrasonic waves having a narrow band frequency of about 60 MHz, the impedance between the impedance Zi of the transmission / reception unit 4p and the impedance Zl of the ultrasonic transducer Tr1. Consistency is achieved. Here, for example, using a Smith chart or the like, the number of coil turns in the inductor L1 and the magnitude of the capacitance in the capacitor C1 are set.

If the configuration shown in FIG. 8A is adopted, the inductor L1 may be contained in either the first conductor layer Cl1 or the second conductor layer Cl2. In other words, the inductor L1 may be integrally made of the same material as the second f wiring W2f, or may be integrally made of the same material as the second s wiring W2s. Thereby, for example, the inductor L1 can be formed when forming the second f wiring W2f or the second s wiring W2s, and the inductor L1 can be easily formed.

<2-2. Third Embodiment>
In each of the first embodiment and the second embodiment, for example, the matching circuit Mc1 and the matching circuit Mc1A are changed to the matching circuit Mc1B according to the third embodiment having a configuration different from that of the matching circuit Mc1 and the matching circuit Mc1A. May be done. The matching circuit Mc1B is, for example, as shown in FIG. 8B, based on the matching circuit Mc1A according to the second embodiment, and is a second inductor between the fourth electrode E4 and the third s connection portion Cr3s. It has a configuration in which L2 is added. In this case, for example, when the ultrasonic transducer Tr1 transmits and receives ultrasonic waves having a wide band frequency of about 30 MHz to 90 MHz, the impedance Zi of the transmission / reception unit 4p and the impedance Zl of the ultrasonic transducer Tr1 Impedance matching is achieved. Here, for example, using a Smith chart or the like, the number of coil turns in the inductors L1 and L2 and the magnitude of the capacitance in the capacitor C1 are designed.

<2-3. Fourth Embodiment>
In each of the first to third embodiments, for example, depending on the magnitude relationship between the impedance Zi of the transmission / reception unit 4p and the impedance Zl of the ultrasonic transducer Tr1, the matching circuits Mc1, Mc1A, and Mc1B are inductors. It may not have L1 or may not have a capacitor C1. For example, the matching circuit Mc1 according to the first embodiment may be the configuration in which the capacitor C1 is removed from the configuration of FIG. 4, or the inductor L1 may be excluded from the configuration of FIG. In other words, the matching circuit Mc1 may include, for example, at least one of the inductor L1 and the capacitor C1.

<2-4. Fifth Embodiment>
In each of the first to fourth embodiments, for example, the portion of the insulating layer Il4 in contact with the inductor L1 has irregularities or a plurality of openings so that the inductor L1 is aligned with the concave-convex surface. It may be located in a wavy manner. For example, as shown in FIG. 9, it is conceivable that the insulating layer Il4 has a plurality of openings Hl1 so that the inductor L1 is located so as to undulate along the uneven surface Fr1. Thereby, for example, the length of the inductor L1 in the longitudinal direction can be increased on the substrate Ss1 as the cavity layer. Here, for example, when forming the first opening O1 and the second opening O2 with respect to the layer of the insulator, a plurality of openings Hl1 can be formed. For example, if the thickness of the insulating layer Il4 is 1 μm and a plurality of openings Hl1 having a diameter d2 of 15 μm are formed so that the interval d1 is 5 μm, the total length of the inductor L1 can be increased by about 9%. The interval d1 and the diameter d2 may be changed as appropriate.

<2-5. 6th Embodiment>
In each of the first to fifth embodiments, for example, as shown in FIGS. 10A and 10B, the second wiring W2s is a lower layer wiring portion in the inductor L1 portion. It may have W2sb and an upper layer wiring portion W2su. In FIG. 10A, the description of the configuration other than the second conductor layer Cl2 on the base material Ss1 is omitted. If such a configuration is adopted, for example, the length of the inductor L1 in the longitudinal direction can be increased on the substrate Ss1 as the cavity layer. In the examples of FIGS. 10 (a) and 10 (b), the upper wiring portion W2su is located on the insulating layer Il5 which is located so as to cover the lower wiring portion W2sb. The material of the insulating layer Il5 may be, for example, an inorganic insulating material such as silicon dioxide, or an organic insulating material. The thickness of the insulating layer Il5 is set as appropriate, for example. Then, the first end portion of the lower layer wiring portion W2sb and the first end portion of the upper layer wiring portion W2su are in a state of being electrically connected via the through hole TH1 of the insulating layer Il5. .. The insulating layer Il5 can be formed using, for example, TEOS-CVD or the like. Through-hole TH1 can be formed, for example, by dry or wet etching. Here, as shown in FIG. 10A, when the plane is seen through in the −Z direction, the wiring portion W2sb in the lower layer and the wiring portion W2su in the upper layer may be displaced so as not to overlap each other. For example, the parasitic capacitance between the lower layer wiring portion W2sb and the upper layer wiring portion W2su can be reduced.

<3. Others>
In each of the first to sixth embodiments, for example, a state in which the first electrode E1 and the third electrode E3 are integrally made of the same material, and the second electrode E2 and the fourth electrode It may be in at least one of the states in which E4 and E4 are integrally made of the same material.

In each of the first to sixth embodiments, for example, a configuration is adopted in which the arrangement of the first conductor layer Cl1 and the arrangement of the second conductor layer Cl2 are upside down on the substrate Ss1. May be good.

In each of the first to sixth embodiments, for example, the ultrasonic transducer Tr1 may have one ultrasonic transducer UV1 or a plurality of ultrasonic transducers UV1. It may be.

In each of the first to sixth embodiments, for example, the ultrasonic transducer UV1 has a configuration of a type called cMUT (Capacitive Micro-machined Ultrasound Transducers) instead of having a configuration of pMUT. You may be doing it.

In each of the first to sixth embodiments, for example, the circular cross section of the cavity Cv1 along the XY plane may have an appropriate shape other than the circular shape.

In each of the first to sixth embodiments, for example, the substrate Ss1 may be bonded directly to another support substrate or indirectly via another layer. In this case, the substrate Ss1 becomes a cavity layer having a cavity Cv1 located on the support substrate.

The ultrasonic detection device 100 according to each of the first to sixth embodiments is a fault inside a blood vessel, for example, in a pipe or in a narrow space, for viewing a tomographic image of an object located in the surroundings. It may be applied for purposes other than viewing images. In this case, the ultrasonic detection device 100 may include, for example, an elongated sensor unit 21 and a transmission / reception unit 4p.

Needless to say, all or a part of the first embodiment to the sixth embodiment and various modifications can be combined as appropriate within a consistent range.

4p Transmitter / Receiver 22 Ultrasonic Detector 100 Ultrasonic Detector C1 Capsule Cl1 1st Conductor Layer Cl2 2nd Conductor Layer Cr1 1st Connection Cr1f 1f Connection Cr1s 1s Connection Cv1 Cavity D1 Pioxyde D2 Dielectric Part E1 1st electrode E2 2nd electrode E3 3rd electrode E4 4th electrode L1, L2 inductor Mc1, Mc1A, Mc1B matching circuit Se1 vibrating layer Ss1 base Tr1 ultrasonic transducer UV1 ultrasonic transducer W1 wiring part W1f 1st f wiring W1s 1st s wiring W2f 2nd f wiring W2s 2s wiring

Claims (7)

Cavity layer with cavities and
It comprises a connection, a matching circuit and an ultrasonic transducer, respectively located on the cavity layer.
A state in which the connection unit can electrically connect a transmission / reception unit that transmits / receives an electric signal to / from the ultrasonic transducer, and is connected to the ultrasonic transducer via the matching circuit. Located in,
The ultrasonic transducer includes an ultrasonic transducer located above the cavity and having a first electrode and a second electrode.
An ultrasonic probe in which the matching circuit is a circuit for matching the impedance of the transmission / reception unit with the impedance of the ultrasonic transducer, and includes at least one of an inductor and a capacitor. The ultrasonic probe according to claim 1.
The matching circuit includes the capacitor and
The ultrasonic oscillator includes a piezoelectric portion located sandwiched between the first electrode and the second electrode.
The capacitor includes a dielectric portion and
An ultrasonic probe in which the material of the piezoelectric portion and the material of the dielectric portion are the same. The ultrasonic probe according to claim 1.
The matching circuit includes the capacitor and
The capacitor includes a dielectric portion and a third electrode and a fourth electrode located so as to sandwich the dielectric portion.
A state in which the first electrode and the third electrode are integrally made of the same material, and a state in which the second electrode and the fourth electrode are integrally made of the same material. An ultrasonic probe in at least one state. The ultrasonic probe according to any one of claims 1 to 3.
The wiring located in a state where the connecting portion and the first electrode are electrically connected, or the wiring located in a state where the connecting portion and the second electrode are electrically connected , An ultrasonic probe located in a state of being integrally made of the same material as the inductor. The ultrasonic probe according to any one of claims 1 to 4.
An ultrasonic probe in which the inductor is located so as to surround the ultrasonic transducer when the ultrasonic transducer, the matching circuit, and the cavity layer are viewed through a plane. The ultrasonic probe according to any one of claims 1 to 5.
An ultrasonic probe in which the inductor is located so as to undulate along an uneven surface. The ultrasonic probe according to any one of claims 1 to 6,
An ultrasonic detection device including the transmission / reception unit located in a state of being electrically connected to the connection unit.

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