Ultrasonic probe

The present invention relates to an ultrasonic probe used when performing an extracorporeal scan or an intracorporeal scan of a subject.

In the medical field, various imaging techniques have been developed for observing the inside of a subject and making a diagnosis. In particular, ultrasonic imaging, which acquires internal information of a subject by transmitting and receiving ultrasonic waves, enables real-time image observation and is used for other medical purposes such as X-ray photography and RI (radio isotope) scintillation cameras. Unlike imaging technology, there is no radiation exposure. Therefore, ultrasonic imaging is used as a highly safe imaging technique in a wide range of fields including gynecological, circulatory, and digestive systems, in addition to fetal diagnosis in the obstetrics field.

Ultrasonic imaging is an image generation technique that utilizes the property of ultrasonic waves being reflected at boundaries of regions with different acoustic impedances (for example, boundaries of structures). Usually, an ultrasonic imaging device (also called an ultrasonic diagnostic device or an ultrasonic observation device) is used by inserting it into an ultrasonic probe used in contact with a subject or into the body cavity of the subject. It is equipped with an ultrasonic probe. Alternatively, an ultrasonic endoscope in which an endoscope for optically observing the inside of a subject and an ultrasonic probe for the inside of a body cavity may be provided may be provided. An ultrasonic beam is transmitted from such an ultrasonic probe or an ultrasonic endoscope (hereinafter referred to as an ultrasonic probe or the like) into a subject such as a human body to perform an ultrasonic probe. Ultrasound image information is acquired by receiving an ultrasonic echo generated in a subject using a child or the like. By obtaining the reflection point and the reflection intensity at which the ultrasonic echo is generated based on this ultrasonic image information, the outline of the structure (for example, internal organs, lesion tissue, etc.) existing in the subject is extracted.

In general ultrasonic probes, piezoelectric ceramics such as PZT (lead zirconate titanate) and PVDF (polyvinylidene fluoride) are used as ultrasonic transducers that transmit and receive ultrasonic waves. : Polyvinylidene difluoride) is composed of a transducer (piezoelectric transducer) in which electrodes are formed at both ends of a piezoelectric material (piezoelectric body) such as a polymer piezoelectric element. When a pulsed or continuous wave electric signal is sent to the electrodes of such an oscillator to apply a voltage, the piezoelectric body expands and contracts. Due to this expansion and contraction, pulsed or continuous wave ultrasonic waves are generated from each oscillator, and an ultrasonic beam is formed by synthesizing these ultrasonic waves. In addition, each oscillator expands and contracts by receiving propagating ultrasonic waves to generate an electric signal. These electric signals are output as ultrasonic detection signals. By arranging a plurality of such ultrasonic transducers and driving them in sequence, an ultrasonic beam is formed by synthesizing the ultrasonic waves transmitted from the respective ultrasonic transducers, and the subject is electronically scanned.

By the way, ultrasonic probes include one-dimensional array probes, two-dimensional array probes, annular (annular) array probes, etc., depending on the arrangement of a plurality of ultrasonic transducers, and depending on the scanning method. , Linear scan type, sector scan type, convex scan type, radial scan type, etc.

Among them, a two-dimensional array probe in which a plurality of ultrasonic transducers are arranged in a two-dimensional manner is particularly attracting attention. By using a two-dimensional array probe, the subject can be scanned two-dimensionally by the ultrasonic beam without moving itself, including the depth direction of the subject (the traveling direction of ultrasonic waves) 3 This is because it is possible to acquire two-dimensional ultrasonic image information. As a result, it is possible to compose an image showing a desired cross section of the subject and to compose a stereoscopic image (three-dimensional image) of the subject (volume imaging).

If a three-dimensional image can be generated by ultrasonic imaging, it will be possible to make a very useful diagnosis in various medical fields. For example, in obstetrics, fetal diagnosis can be performed by observing the development and growth of a foetation in real time with a moving image. Specifically, by continuously observing changes in the volume of the brain and growth of the spine, it becomes possible to detect and respond to fetal abnormalities at an early stage. Alternatively, it has been attempted to treat the foetation in the body cavity with reference to a three-dimensional ultrasonic image. Further, in the cardiology department, it becomes possible to detect a heart disease by observing a change in the volume of the heart based on a three-dimensional ultrasonic image. Such demand is particularly high in Europe and the United States. Furthermore, in the field of urology, there is a great deal of interest in 3D ultrasound images.

However, compared to the one-dimensional array, the technical problem in producing the two-dimensional array is very large. First, the number of ultrasonic transducers increases dramatically by making the array of ultrasonic transducers two-dimensional. Therefore, it becomes difficult to electrically pull out the wiring from each ultrasonic transducer. Secondly, since the number of shielded wires increases dramatically with the number of ultrasonic transducers, the cable connecting the ultrasonic probe and the ultrasonic diagnostic device main body becomes thick. This makes it difficult to handle the ultrasonic probe. In addition, it can be said that the large diameter of the cable in the ultrasonic probe for observing the inside of the body cavity is a fatal defect.

As a related technique, Patent Document 1 discloses an electrode extraction structure of a two-dimensional array probe. That is, in Patent Document 1, a two-dimensional transducer in which a signal line is passed through a backing material and a signal electrode at one end of the signal line is two-dimensionally arranged as an electrode pattern parallel to an array surface of a vibrating element, and the signal electrode A two-dimensional array probe is configured by connecting a relay board having an electrode pattern similar to that of the above electrode pattern and an IC board vertically connected to the relay board.

However, according to such a wiring drawing method, the connection of the address electrodes may be uncertain. Therefore, for example, it is extremely difficult to reliably connect each of 1000 to 4000 ultrasonic transducers to the electrical wiring.

In Patent Document 2, in an ultrasonic probe having oscillators arranged in a two-dimensional matrix, an electric circuit connected to each element of the oscillator and transmitting and receiving a signal is set at intervals corresponding to the elements of the oscillator. It is composed of signal lines arranged one-dimensionally on the base film, and the base film part of the probe for connecting the signal lines to the oscillator element is sandwiched between acoustic sound absorbing materials and bonded. Discloses that it constitutes a two-dimensional array type ultrasonic probe. That is, in Patent Document 2, the ends of a plurality of signal lines are formed by alternately joining a base film (flexible pattern circuit) on which a plurality of signal lines are formed and an acoustic sound absorbing material (backing material). The parts are arranged in a two-dimensional manner according to the arrangement of the vibrators in a two-dimensional matrix.

However, even in Patent Document 2, the uncertainty of the connection between each oscillator and the signal line remains. Further, according to the method for manufacturing an ultrasonic probe disclosed in Patent Document 2, the ultrasonic transducer is arranged so that the ultrasonic radiation surface is flat, so that, for example, a planar array used for chest observation is used. (Sector scan array) can be made. However, it is not possible to create a convex array (eg, used for fetal observation) that has an overall convex ultrasonic radiation surface.

Patent Document 3 has a structure in which a printed circuit board for drawing signal leads and grounds from each transducer is arranged at intervals between rows of elements arranged in a matrix in a two-dimensional array ultrasonic probe, and is provided on the printed circuit board. It is disclosed that a printed circuit board on which a transducer is mounted is arranged in a row direction to form a two-dimensional array transducer after mounting a transducer array corresponding to one row.

Further, in Patent Document 4, the printed substrate, a plurality of array lines formed on the printed substrate at a predetermined pitch, and the first side surfaces of the array lines are arranged in a row so as to correspond to each other. A conductive thin plate that commonly connects the second side surface of the plurality of laminated piezoelectric elements arranged in a row and the second side surface opposite to the first side surface, and a wiring line on the printed substrate. Units including a backing material formed so as to cover are formed side by side at a predetermined pitch, and the first side surface and the second side surface of the laminated piezoelectric element have conductivity, and a plurality of laminated piezoelectric elements are provided. The piezoelectric material and the plurality of internal electrode layers are alternately laminated, and the plurality of internal electrodes are alternately connected to one of the first side surface or the second side surface.

In Patent Documents 3 and 4, a plurality of wiring lines are formed side by side on a flexible printed substrate, and a plurality of ultrasonic transducers are connected to the wiring lines on their side surfaces (planes orthogonal to the ultrasonic radiation plane). The unit is made by this. Then, a two-dimensional array is manufactured by stacking a plurality of such units. According to such a manufacturing method, each ultrasonic transducer can be reliably connected to the signal line. However, again, the ultrasonic radiation surface of the two-dimensional array cannot be curved.<patcit num="1"><text>Japanese Unexamined Patent Publication No. 2001-292496 (page 1)</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 2000-214144 (page 1)</text></patcit><patcit num="3"><text>Japanese Unexamined Patent Publication No. 2001-309493 (page 1)</text></patcit><patcit num="4"><text>Japanese Patent Application Laid-Open No. 2005-210245 (1st page)</text></patcit>

<p> Therefore, in view of the above points, it is an object of the present invention to provide an ultrasonic probe that can be manufactured relatively easily and has a desired ultrasonic radiation surface.</p>

<p> In order to solve the above problems, the ultrasonic probe according to one aspect of the present invention is an ultrasonic probe having an ultrasonic radiation surface, which is a plurality of supports and is an ultrasonic probe. Multiple signal lines of children were formed<u style="single">One surface</u>A plurality of supports arranged so that the normals of the main surfaces face different directions, and a plurality of groups of ultrasonic transducers, and a plurality of ultrasonic transducers in each group. It has a plurality of electrodes formed on the side surface, and each of the plurality of electrodes<u style="single">Correspond</u>It is joined to a plurality of signal lines formed on the main surface of the support, respectively.<u style="single">The formed two-dimensional ultrasonic radiation surface has the desired shape as a whole.</u>It includes a plurality of groups of ultrasonic transducers.</p>

<p> According to the present invention, an ultrasonic probe having a desired ultrasonic radiation surface can be obtained by arranging supports to which a plurality of ultrasonic transducers are joined so that their normals point in different directions. It can be manufactured relatively easily.</p>

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. The same components are given the same reference numbers, and the description thereof will be omitted. FIG. 1 is a perspective view showing the appearance of the ultrasonic probe according to the first embodiment of the present invention. As shown in FIG. 1, the ultrasonic probe according to the present embodiment includes a plurality of one-dimensional arrays 1. Each one-dimensional array 1 contains a plurality of (four in FIG. 1) ultrasonic transducers 1a arranged one-dimensionally in the elevation direction. Such a one-dimensional array 1 is arranged so as to be radial in the azimuth direction (scanning direction). As a result, the two-dimensional ultrasonic radiation surface 200 formed by the ultrasonic radiation surfaces 100 of the plurality of ultrasonic transducers 1a has a desired shape as a whole (in FIG. 1, a curved surface shape corresponding to a part of the side surface of the cylinder). )become.

These one-dimensional arrays 1 are held by a backing material (also a holding member) 2 formed of a material having a large acoustic attenuation. As the material of the backing material 2, for example, a resin material such as epoxy or natural rubber mixed with powders such as ferrite, metal, PZT, and tungsten carbide and dispersed is used. Although FIG. 1 shows a columnar body having a convex upper surface as the backing material 2, the shape of the backing material 2 is not limited to such a shape, for example, a semi-cylinder or a fan column. It may be. A lead wire 3 is connected to each one-dimensional array 1.

FIG. 2 is a perspective view showing the structure of the one-dimensional array 1 shown in FIG. Each one-dimensional array 1 includes a substrate 10 on which the wiring 11 is formed, and a plurality of ultrasonic transducers 1a bonded to the substrate 10 on the side surface (a surface different from the ultrasonic radiation surface 100 and the opposite side). There is. The substrate 10 is used as a support for supporting a plurality of ultrasonic transducers 1a.

Each ultrasonic transducer 1a includes at least an oscillator (piezoelectric oscillator) 12 for transmitting and receiving ultrasonic waves and an acoustic matching layer 13, and may further include an acoustic lens 14 and a backing layer 15. Further, the filler 16 may be arranged between two adjacent ultrasonic transducers 1a.

The substrate 10 is made of silicon (Si) or silicon oxide (SiO).₂), Silicon Carbide (SiC), Glass Epoxy, Polyimide, Alumina (Al₂O₃) Or a hard material such as zirconia, and has a thickness of, for example, about 50 μm to 100 μm. The hardness of the substrate 10 is such that when a part of the substrate 10 is inserted into the backing material 2, the portion protruding from the backing material 2 (FIG. 1) does not become unstable, preferably enough to stand upright. You just have to have it. Further, when a silicon chip is used as the substrate 10, the wiring 11 may be formed by a semiconductor process. In this case, narrow pitch wiring can be formed in a short process.

The wiring 11 is a transmission line that supplies a drive signal to the oscillator 12 described later and transmits an electric signal output from the oscillator 12. The lead wire 3 shown in FIG. 1 is connected to these wires 11.

The transducer 12 is a piezoelectric material 12a such as a piezoelectric ceramic represented by PZT (lead zirconate titanate) or a polymer piezoelectric element represented by PVDF (polyvinylidene fluoride), and electrodes 12b formed on both sides thereof. And 12c and are included. When a pulsed or continuous wave electric signal is sent to these electrodes 12b and 12c to apply a voltage, the piezoelectric body expands and contracts, and this expansion and contraction generates pulsed or continuous wave ultrasonic waves from the respective oscillators. ..

The acoustic matching layer 13 is formed of, for example, Pyrex (registered trademark) glass or epoxy resin containing metal powder, which easily propagates ultrasonic waves, and is arranged on the ultrasonic radiation surface 100 side of the vibrator 12. Eliminates the mismatch of acoustic impedance between the subject, which is a living body, and the ultrasonic transducer 12. As a result, the ultrasonic waves transmitted from the ultrasonic transducer are efficiently propagated in the subject. Although one acoustic matching layer 13 is shown in FIG. 2, a plurality of acoustic matching layers may be arranged as needed.

The acoustic lens 14 is made of, for example, silicone rubber, and focuses an ultrasonic beam transmitted from a plurality of ultrasonic transducers 1a and propagating through the acoustic matching layer 13 at a predetermined depth in a subject. The backing layer 15 is formed of a material having a large acoustic attenuation, such as an epoxy resin containing ferrite powder, metal powder, or PZT powder, or rubber containing ferrite powder, and is an unnecessary ultrasonic wave generated from the vibrator 12. Accelerate the attenuation of ultrasonic waves. Further, the filler 16 stabilizes the position of each ultrasonic transducer 1a and reduces the interference between the plurality of oscillators 12.

Such an ultrasonic transducer 1a is attached to the substrate 10 by joining the electrodes 12b and 12c of the vibrator 12 to the wiring 11 using a conductive paste (not shown). The conductive paste is, for example, an adhesive in which a metal powder is mixed with a resin base material such as an epoxy resin. By using the conductive paste, the conductivity between the wiring 11 and the vibrator 12 is ensured. Further, since the conductive paste has a certain degree of elasticity, it is possible to reduce the braking due to the expansion and contraction of the vibrator 12 as compared with the case where solder is used, for example.

FIG. 3 shows the side surface of the ultrasonic probe shown in FIG. As shown in FIG. 3, a plurality of grooves 2a are formed in the backing material 2, and by inserting the substrate 10 shown in FIG. 2 into the grooves 2a to the lower end of the backing layer 15, the one-dimensional array 1 is formed. It is being held. Further, the lead wire 3 connected to each one-dimensional array 1 is pulled out to the side of the backing material 2 through the bottom portion of the groove 2a.

Next, a method for manufacturing an ultrasonic probe according to the first embodiment of the present invention will be described. First, as shown in FIG. 4, a hard material such as silicon (Si) is formed into the shape of the substrate 10, and the common wiring 11a connected to the plurality of oscillators 12 and each oscillator 12 (FIG. 2) are supported. The individual wiring 11b is formed. As a method for forming the wiring, a generally used method such as lift-off processing may be used, or when a silicon chip is used as the substrate, a semiconductor process may be used.

On the other hand, as shown in FIG. 5, a plate-shaped ultrasonic transducer member 20 is manufactured. That is, first, the electrode layers 22a and 22b are formed on both sides of the piezoelectric body 21 by using a general method such as a vapor deposition method or a sputtering method. At that time, the electrode layers 22a and 22b are wrapped around the side surface of the piezoelectric body 21 (wrap-around electrodes 26a and 26b). Then, the acoustic matching layer 23 and the acoustic lens 24 are arranged on one electrode layer 22a side, and the backing layer 25 is arranged on the other electrode layer 22b side. These layers (acoustic matching layer 23, acoustic lens 24, and backing layer 25) may be formed by joining the molded members with, for example, a synthetic resin-based adhesive.

Next, as shown in FIG. 6A, the common wiring 11a and the individual wiring 11b formed on the substrate 10 are joined to the wraparound electrodes 26a and 26b (FIG. 5) of the ultrasonic transducer member 20. Conductive pastes 27a and 27b are placed in the portions. Then, as shown in FIG. 6B, the conductive paste arranging surface of the substrate 10 and the wraparound electrodes 26a and 26b forming surfaces of the ultrasonic transducer member 20 are bonded to each other. As a result, as shown in FIG. 7, the substrate 10 and the ultrasonic transducer member 20 are integrated.

Here, it is desirable that the conductive pastes 27a and 27b are arranged thickly in order to reduce braking due to expansion and contraction of the vibrator 12 (FIG. 2). For example, if the thicknesses of the conductive pastes 27a and 27b are about 10 μm to 20 μm, it is possible to vibrate the vibrator 12, and about 30 μm to 50 μm is sufficient.

Next, as shown in FIG. 8A, the ultrasonic transducer member 20 is diced to be divided into a plurality of ultrasonic transducers 1a. In that case, as shown in FIG. 8 (b), dicing is stopped at a depth in front of the wiring 11a (preferably halfway through the conductive paste 27a) so as not to cut the wiring 11a. Then, as shown in FIGS. 9A and 9B, the synthetic resin-based filler 16 is arranged in the groove 20a formed by dicing. As a result, the one-dimensional array 1 is completed. Next, as shown in FIG. 9A, the ground lead wire 28a is connected to the common wiring 11a by soldering, and the address lead wire 28b is connected to each individual wiring 11b by soldering.

In addition, a backing material 2 for holding a plurality of one-dimensional arrays 1 is separately prepared. That is, as shown in FIG. 10, the upper surface 2b of the resin material or the like in which the ferrite powder or the like is dispersed is formed so as to be curved in one direction (azimuth direction), and further, a groove for inserting the one-dimensional array 1 is inserted. Form 2a. The depth of the groove 2a should be slightly deeper than the insertion portion of the substrate 10 (the length from the lower end of the substrate 10 to the lower end of the backing layer 15 shown in FIG. 2). This is to secure a space for arranging the ground leader wire 28a and the address leader wire 28b of the one-dimensional array 1.

Next, as shown in FIG. 11, the one-dimensional array 1 is inserted into the groove 2a of the backing material 2. In that case, it is desirable to arrange an adhesive in the groove 2a to fix the substrate 10. Further, the ground lead wire 28a and the address lead wire 28b are pulled out from the bottom of the groove 2a to the side of the backing material 2. As a result, the ultrasonic probe shown in Fig. 1 is completed.

As described above, according to the present embodiment, it is possible to easily manufacture a two-dimensional ultrasonic probe having an ultrasonic radiation surface having a desired shape. In the present embodiment, as shown in FIG. 8, the ultrasonic transducer member 20 is attached to the substrate 10 and then divided into the ultrasonic transducer 1a. However, a plurality of ultrasonic transducers 1a pre-cut to a desired width may be arranged on the substrate 10 at desired intervals.

Next, a second embodiment of the present invention will be described. The second embodiment is different from the first embodiment in that an integrated circuit is formed on the substrate 10 shown in FIG. 2, and is the same as the first embodiment in other respects.

FIG. 12 is a plan view showing a substrate used in the ultrasonic probe according to the second embodiment of the present invention. In this embodiment, a semiconductor substrate such as a silicon chip is used as the substrate 10. An integrated circuit including a plurality of MOSFETs (metal oxide semiconductor field effect transistor, hereinafter simply referred to as transistor) is formed in the circuit formation region 10a of the substrate 10. Further, a common wiring 11a, an individual wiring 11b, and an input / output terminal 11c are formed on the substrate 10.

FIG. 13 is a cross-sectional view showing a cross section of a part of the circuit formation region in the alternate long and short dash line XIII-XIII shown in FIG. As shown in FIG. 13, N wells 101 and P wells 102 are formed in the P-shaped substrate 10. On the other hand, the gate electrodes 104 and 105 are formed on the substrate 10 via the gate insulating film 103. In the N wells 101 on both sides of the gate electrode 104, P-type impurity diffusion regions 106 and 107 serving as sources or drains are formed, and these form a P-channel transistor QP. Further, N-type impurity diffusion regions 108 and 109 serving as sources or drains are formed in the P wells 102 on both sides of the gate electrode 105, and the N-channel transistor QN is formed by these. Further, an interlayer insulating film 110 is formed on the substrate 10, and individual wiring 11b is connected to the source or drain of the transistors QP and QN via a through hole provided in the interlayer insulating film 110. .. It should be noted that the multilayer wiring may be realized by forming a plurality of sets of the interlayer insulating film and the wiring layer.

FIG. 14 is a circuit diagram showing a first circuit example formed in the circuit forming region shown in FIG. In the first circuit example, by connecting the multiplexer 130 to the four oscillators 121 to 124, one or more of these oscillators 121 to 124 are selectively connected to the input / output terminals 11c. Will be done.

The multiplexer 130 includes a first analog switch composed of a P-channel transistor QP1 and an N-channel transistor QN1, a second analog switch composed of a P-channel transistor QP2 and an N-channel transistor QN2, and a P-channel transistor QP3 and N. A third analog switch composed of the channel transistor QN3, a fourth analog switch composed of the P-channel transistor QP4 and the N-channel transistor QN4, and an inverter INV1 ~ that inverts the control signal supplied to each analog switch. Includes INV4.

Further, a control circuit 140 is provided to control the multiplexer 130. The control circuit 140 generates a control signal for controlling each analog switch according to a timing signal supplied wirelessly or by wire from the outside of the ultrasonic probe.

FIG. 15 is a circuit diagram showing a second circuit example formed in the circuit forming region shown in FIG. In the second circuit example, the preamplifiers 151 to 154 and the preamplifiers 151 to 154 that amplify the electric signals output from the four transducers 121 to 124, respectively, with respect to the first circuit example shown in FIG. Parallel / serial conversion that converts the parallel data output from the A / D converters 161 to 164 that convert the output signal into digital signals and the A / D converters 161 to 164 into serial data and supplies it to the input / output terminals 11c. Circuit 170 and is added. The parallel / serial conversion circuit 170 operates in synchronization with a clock signal generated by the parallel / serial conversion circuit 170 itself or a clock signal supplied wirelessly or by wire from the outside of the ultrasonic probe.

In the second circuit example, the electric signals output from the four vibrators 121 to 124 are supplied to the input / output terminals 11c as serial data when the ultrasonic waves are received, and are input when the ultrasonic waves are transmitted. The drive signal supplied to the output terminal 11c can be applied to one or more of the four vibrators 121 to 124.

According to this embodiment, fine wiring can be formed at low cost and by a simple process. This makes it possible to arrange a plurality of ultrasonic transducers 1a at a narrow pitch. Therefore, it is possible to reduce the size of the ultrasonic probe including the one-dimensional array or the two-dimensional array in which a plurality of one-dimensional arrays are arranged at low cost.

Further, according to the present embodiment, the number of shielded wires connected to the ultrasonic probe can be reduced. For example, when making a two-dimensional array in which ultrasonic transducers are arranged in 32 rows x 32 columns, 32 x 32 = 1024 shielded wires are usually required. However, by providing a multiplexer in each one-dimensional array, the number of shielded wires becomes 32. Therefore, even if 6-bit control lines connected to each 1D array are added, the total number of wires can be suppressed to 224 (32 shielded lines, 6 x 32 = 192 control lines). .. As a result, the diameter of the cable connecting the ultrasonic probe and the ultrasonic diagnostic apparatus main body can be reduced.

Next, the ultrasonic probe and the method for manufacturing the same according to the third embodiment of the present invention will be described with reference to FIG. Here, in the first and second embodiments of the present invention described above, a two-dimensional array is formed by inserting a plurality of one-dimensional arrays 1 (FIG. 1) into one backing material 2. On the other hand, the present embodiment is characterized in that a two-dimensional array is held by joining a backing material (also serving as a holding member) to each one-dimensional array and assembling a plurality of backing materials.

First, in the method for manufacturing the ultrasonic probe according to the first embodiment, the one-dimensional array 1 is produced in the same manner as described with reference to FIGS. 4 to 9, and the lead wire 3 (FIG. 9) is produced. Connect the ground lead wire 28a and the address lead wire 28b). On the other hand, as shown in FIG. 16A, a resin material or the like in which ferrite powder or the like is dispersed is formed into a columnar shape having a fan-shaped bottom surface, and a notch is provided in a part thereof for backing. Material 4 is prepared.

Then, as shown in FIG. 16 (b), the portion of the substrate 10 of the one-dimensional array 1 is integrated by adhering it to the notch 4a of the backing material 4. At that time, the lead wire 3 is pulled out sideways from the bottom of the notch 4a. The number of pieces integrated in this way is prepared for the number of one-dimensional arrays 1 arranged in the azimuth direction (FIG. 1). Further, as shown in FIG. 16 (c), a plurality of pieces are assembled by joining the backing materials 4 with an adhesive. As a result, a two-dimensional ultrasonic probe having a curved ultrasonic radiation surface is completed.

Next, the ultrasonic probe according to the fourth embodiment of the present invention will be described with reference to FIGS. 17 and 18. In the ultrasonic probe according to the first to third embodiments of the present invention, a single-layer piezoelectric vibrator in which electrode layers are formed on both sides of one piezoelectric body is used, but the present embodiment Instead, a laminated piezoelectric vibrator having a plurality of piezoelectric layers is used.

FIG. 17 is a partial cross-sectional perspective view showing the structure of the laminated piezoelectric vibrator. The laminated piezoelectric vibrator 30 includes a plurality of piezoelectric layers 31, internal electrode layers 32a and 32b, insulating films 33a and 33b, side electrodes 34a and 34b, a lower electrode 35, and an upper electrode 36. I'm out. The piezoelectric layer 31 and the internal electrode layers 32a and 32b are alternately laminated.

The insulating film 33a is formed at one end (left side in the figure) of the internal electrode layer 32a, whereby the internal electrode layer 32a is insulated from the side electrode 34a and electrically connected to the side electrode 34b. Be connected. Further, the insulating layer 33b is formed at the other end (right side in the figure) of the internal electrode layer 32b, whereby the internal electrode layer 32b is insulated from the side electrode 34b and becomes the side electrode 34a. It is electrically connected. Further, the lower electrode layer 35 is connected to the side electrode 34a, and the upper electrode layer 36 is connected to the side electrode 34b.

By arranging the electrodes of the laminated piezoelectric vibrator in this way, a plurality of units each including one piezoelectric layer 31 and electrodes arranged on both sides thereof (for example, internal electrode layers 32a and 32b) can be formed. Connected in parallel. When a voltage is applied to the lower electrode 35 and the upper electrode 36 of the laminated piezoelectric vibrator, electric fields in opposite directions are alternately applied to the plurality of piezoelectric layers 31. In such a laminated piezoelectric vibrator, the area of the opposing electrodes can be substantially increased as compared with the single-layer vibrator, so that the electrical impedance can be lowered. Therefore, it operates more efficiently with respect to the applied voltage than the single-layer oscillator.

As shown in FIG. 18, when the laminated piezoelectric vibrator 30 is attached to the substrate 10, the conductive paste 37 may be used. Here, the side surface of the laminated piezoelectric vibrator 30 is partially raised by the amount of the insulating films 33a and 33b, but by arranging the conductive paste 37 thickly, the side surface is raised regardless of such raising. The electrode 34b (or 34a) and the lower electrode 35 (or the upper electrode 36) can be stably connected to the wirings 11a and 11b of the substrate 10. Further, in order to reduce the braking due to the expansion and contraction of the laminated piezoelectric vibrator 30, it is desirable to arrange the conductive paste 37 thickly.

Next, the ultrasonic probe according to the fifth embodiment of the present invention will be described with reference to FIG. As shown in FIG. 19A, in the present embodiment, a plurality of ultrasonic transducers 1a are arranged on the substrate 10 so that the heights of the respective ultrasonic radiation surfaces 100 deviate from each other. Fabricate the ultrasonic transducer array 5. Then, as shown in FIG. 19 (b), such an ultrasonic transducer array 5 is arranged on the backing material 2 formed so that the upper surface is curved in the azimuth direction. As a result, it is possible to form an ultrasonic radiation surface 210 that is curved not only in the azimuth direction but also in the elevation direction. By using a two-dimensional ultrasonic probe having such a curved ultrasonic radiation surface 210, it becomes possible to transmit ultrasonic waves to a wider area in the subject.

Here, in FIG. 19A, a plurality of ultrasonic transducers 1a are arranged so that the plurality of ultrasonic radiation surfaces 100 are arranged in a convex shape, but even if the plurality of ultrasonic wave radiation surfaces 100 are arranged in a concave shape. good. In this case, by driving a plurality of ultrasonic transducers 1a at the same time, it becomes possible to form a focused ultrasonic beam.

Next, the ultrasonic probe according to the sixth embodiment of the present invention will be described with reference to FIG. In the present embodiment, a plurality of ultrasonic transducers 1a are radially arranged on the substrate 10 so that the ultrasonic radiation surfaces 100 face different directions from each other. Then, such an ultrasonic transducer array 6 is arranged on the backing material 2 (see (b) of FIG. 19) formed so that the upper surface is curved in the azimuth direction. As a result, it is possible to form an ultrasonic radiation surface that is curved not only in the azimuth direction but also in the elevation direction. In this case, the transmission region of ultrasonic waves in the elevation direction can be further expanded as compared with that shown in FIG.

Further, as a modification of the ultrasonic probe according to the present embodiment, as shown in FIG. 21, a plurality of ultrasonic transducer arrays 6 (FIG. 20) are arranged so as to be parallel to each other in two dimensions. An array may be formed. In this case, it is possible to form the ultrasonic radiation surface 220 that is curved only in the elevation direction.

Next, a modified example of the ultrasonic probe according to the first to sixth embodiments of the present invention will be described with reference to FIGS. 22 and 23. In the ultrasonic probe according to the first to sixth embodiments described above, various types can be obtained by changing the shape of the backing material that holds the one-dimensional array 1 and the ultrasonic transducer arrays 5 and 6. Ultrasonic transducer arrays can be made.

As shown in FIG. 22, a radial ultrasonic transducer having a viewing angle of 360 ° can be manufactured by forming a cylindrical backing material 7 and arranging the one-dimensional array 1 so as to cover the entire side surface thereof. Radial ultrasonic transducers are applied to, for example, ultrasonic probes and ultrasonic endoscopes used for observing the inside of a body cavity of a subject. In particular, by combining this modification with the ultrasonic probe according to the second embodiment including a multiplexer, the size of the array and the diameter of the cable can be reduced in the ultrasonic probe for intracavitary scanning and the like. It is effective because it can be planned.

Further, as shown in FIG. 23, the upper surface of the backing material 8 is formed to have a concave shape, and the one-dimensional array 1 is arranged on the surface to form an ultrasonic beam in which the transmission direction is narrowed to some extent. Can be made into a concave array.

The present invention can be used in an ultrasonic probe used when performing an extracorporeal scan or an intracorporeal scan of a subject.

<figref num="1">It is a perspective view which shows the structure of the probe for ultrasonic waves which concerns on 1st Embodiment of this invention.</figref><figref num="2">It is a perspective view which shows the structure of the one-dimensional array shown in FIG.</figref><figref num="3">It is a side view which shows the ultrasonic probe shown in FIG.</figref><figref num="4">It is a top view which shows the substrate in which the wiring was formed.</figref><figref num="5">It is a perspective view which shows the plate-shaped ultrasonic transducer member.</figref><figref num="6">It is a figure for demonstrating the process of joining a substrate and an ultrasonic transducer member.</figref><figref num="7">It is a schematic diagram which shows the ultrasonic transducer member bonded to the substrate.</figref><figref num="8">It is a figure for demonstrating the process of dicing an ultrasonic transducer member.</figref><figref num="9">It is a top view which shows the one-dimensional array which wiring was formed.</figref><figref num="10">It is a figure for demonstrating the process of preparing a backing material.</figref><figref num="11">It is a figure for demonstrating the process of arranging a one-dimensional array on a backing material.</figref><figref num="12">It is a top view which shows the substrate used in the ultrasonic probe according to the 2nd Embodiment of this invention.</figref><figref num="13">It is sectional drawing which shows the cross section of a part of the circuit formation region in the alternate long and short dash line XIII-XIII shown in FIG.</figref><figref num="14">It is a circuit diagram which shows the 1st circuit example formed in the circuit formation region shown in FIG.</figref><figref num="15">It is a circuit diagram which shows the 2nd circuit example formed in the circuit formation area shown in FIG.</figref><figref num="16">It is a figure for demonstrating the manufacturing method of the probe for ultrasonic waves which concerns on 3rd Embodiment of this invention.</figref><figref num="17">It is a partial cross-sectional perspective view which shows the laminated piezoelectric vibrator used in the ultrasonic probe according to the 4th Embodiment of this invention.</figref><figref num="18">It is a schematic diagram which shows the state of joining the laminated piezoelectric vibrator shown in FIG. 17 to a substrate.</figref><figref num="19">It is a figure for demonstrating the ultrasonic probe according to the 5th Embodiment of this invention.</figref><figref num="20">It is a figure for demonstrating the ultrasonic probe according to the 6th Embodiment of this invention.</figref><figref num="21">It is a perspective view which shows the modification of the ultrasonic probe according to the 6th Embodiment of this invention.</figref><figref num="22">It is a figure which shows the 1st modification of the ultrasonic probe according to 1st to 6th Embodiment of this invention.</figref><figref num="23">It is a figure which shows the 2nd modification of the ultrasonic probe according to 1st to 6th Embodiment of this invention.</figref>

Code description

1 1D array 1a ultrasonic transducer 2, 4, 7, 8 backing material 3 Lead wire 4a notch 5, 6 Ultrasonic Transducer Array 10 board 11 Wiring 11a Common wiring 11b Individual wiring 11c I / O terminal 12, 121 ~ 124 Oscillator 12a, 21 Piezoelectric 12b, 12c electrodes 13, 22 Acoustic matching layer 14, 23 acoustic lens 15, 24 backing layer 16 Filler 20 Ultrasonic Transducer Member 20a groove 22a, 22b Electrode layer 26a, 26b wraparound electrode 27a, 27b, 37 Conductive paste 28a ground lead wire 28b address leader 30 Stacked piezoelectric oscillator 31 Piezoelectric layer 32a, 32b internal electrode layer 33a, 33b insulating film 34a, 34b Side electrodes 35 Lower electrode 36 Upper electrode 100 ultrasonic radiation surface 101 N well 102 P well 103 Gate insulating film 104, 105 Gate electrodes 106 ~ 109 Impurity diffusion region 110 interlayer insulating film 130 multiplexer 140 Control circuit 151 ~ 154 Preamplifier 161 ~ 164 A / D converter 170 Parallel / serial conversion circuit 200, 210, 220 Ultrasonic radiation surface QP1 ~ QP4 P channel transistor QN1 ~ QP4 N channel transistor INV1 ~ INV4 Inverter