Ultrasound probe head, ultrasound probe, and ultrasound diagnostic device

Abstract

The present disclosure provides a novel ultrasonic probe head that is capable of achieving probes of not only a linear type and a convex type but also of a variety of other configurations. An ultrasonic probe head 100 according to the present disclosure has multiple ultrasonic element chips 10 that are arranged at intervals on a flexible base material 20, and each of the ultrasonic element chips 10 comprises multiple piezoelectric MEMS ultrasonic transducers 1 on a substrate 2.

Description

Technical Field

[0001] The present disclosure relates to an ultrasonic probe head, an ultrasonic probe, and an ultrasonic diagnostic apparatus.

Background Art

[0002] An ultrasonic diagnostic apparatus is an inspection apparatus that examines inside the body or inside a structure using ultrasonic waves. Using the ultrasonic probe of this inspection apparatus, ultrasonic waves are transmitted from the body surface into the body, from the inner surface of the circulatory organs or organs into the body, and from the surface of the structure into the structure, and the reflected waves are processed and imaged to interpret the presence or absence of lesions, defects, etc. and perform a diagnosis. Since the displayed image appears to move in real time, it is possible to perform treatment while confirming the position of the lesion, observe blood flow dynamics, etc., and because it is a non-invasive method, it is widely used in the medical field.

[0003] Ultrasonic probes include linear type, sector type, convex type, concave type, etc., and these types are selected according to the observation purpose and observation site. For example, the linear type is used for examining tissues located in shallow sites from the body surface, and the convex type is used for examining tissues located in deep sites from the body surface.

[0004] Patent Document 1 shows an example of the prior art of a convex type ultrasonic probe. The ultrasonic element of such an ultrasonic probe is formed by cutting piezoelectric ceramics sandwiched between electrodes into strip shapes.

[0005] In recent years, ultrasonic probes using piezoelectric MEMS ultrasonic transducers (pMUT: Piezoelectric Micromachined Ultrasonic Transducers) as ultrasonic elements have been developed. Such ultrasonic probes can significantly miniaturize the ultrasonic element and increase the element density. Patent Documents 2 to 4 disclose such ultrasonic probes. For details of MEMS for manufacturing this, for example, Patent Documents 4 and 5 can be referred to.

Prior Art Documents

[0006] [Patent Document 1] Japanese Patent Application Publication No. 8-79895 [Patent Document 2] Japanese Patent Publication No. 2014-146883 [Patent Document 3] Japanese Patent Publication No. 2011-259274 [Patent Document 4] Japanese Patent Publication No. 2016-018835 [Patent Document 5] Special Publication No. 2006-516368 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] As described in Patent Documents 2 to 4, ultrasonic probes using piezoelectric MEMS ultrasonic transducers as ultrasonic elements are typically linear in type because the substrate on which the ultrasonic element is formed is a flat substrate such as a silicon substrate. Furthermore, these ultrasonic probes have the problem of low reliability because the piezoelectric thin film, which is made of a very thin, brittle material, breaks when bent or subjected to impact.

[0008] This disclosure provides a novel ultrasonic probe head that can realize probes of various shapes, not just linear and convex types, and is highly reliable. [Means for solving the problem]

[0009] The present inventors have found that the above problems can be solved by the present disclosure having the following aspects. 《Aspect 1》 An ultrasonic probe head in which multiple ultrasonic element chips are arranged at intervals on a flexible substrate, and each of the multiple ultrasonic element chips includes multiple piezoelectric MEMS ultrasonic transducers on the substrate. 《Aspect 2》 The ultrasonic probe head according to embodiment 1, wherein the flexible substrate has a plurality of openings, and the plurality of ultrasonic element tips are located at the positions of the plurality of openings. 《Aspect 3》 The ultrasonic probe head according to embodiment 1 or 2, wherein the piezoelectric MEMS ultrasonic transducer includes an upper electrode, a piezoelectric thin film, and a lower electrode in that order, the upper electrode facing the flexible substrate side, and the lower electrode facing the substrate side. Appearance 4 The ultrasonic probe head according to embodiment 3, wherein the piezoelectric MEMS ultrasonic transducers are arranged in one or two dimensions, and in each of the ultrasonic element chips, the upper electrode and the lower electrode are connected to upper wiring terminals and lower wiring terminals provided on the outer edge of the ultrasonic element chip by upper wiring and lower wiring, respectively. Appearance 5 An ultrasonic probe head according to any one of embodiments 1 to 4, wherein at least one side of each of the plurality of ultrasonic element tips is 1 mm to 5 mm and the thickness is 1 mm or less. 《Aspect 6》 An ultrasonic probe head according to any one of embodiments 1 to 5, wherein the spacing between each of the plurality of ultrasonic element tips is in the range of 0.1 mm to 3 mm. Appearance 7 An ultrasonic probe head according to any one of embodiments 1 to 6, wherein each of the gaps between the plurality of ultrasonic element chips does not contain a rigid member. 《Aspect 8》 An ultrasonic probe comprising at least an ultrasonic probe head according to any one of embodiments 1 to 7, and a head shape component that constitutes the head shape of the ultrasonic probe head. 《Aspect 9》 An ultrasound diagnostic apparatus comprising at least an ultrasound probe as described in embodiment 8, a processing unit for processing signals from the ultrasound probe, and a display device for converting the signals from the processing unit into an image and displaying it. [Brief explanation of the drawing]

[0010] [Figure 1] FIG. 1(a) shows a side view of an example of the ultrasonic probe head of the present disclosure, FIG. 1(b) shows a plan view of an example of the ultrasonic probe head of the present disclosure, and FIG. 1(c) shows a bottom view of an example of the ultrasonic probe head of the present disclosure. [Figure 2] FIG. 2 shows a plan view of an example of an ultrasonic element chip. [Figure 3] FIG. 3 shows a part of the cross-sectional view taken along the line A-A' of the ultrasonic element chip of FIG. 2. [Figure 4] FIG. 4 shows a part of the cross-sectional view taken along the line B-B' of the ultrasonic element chip of FIG. 2. [Figure 5] FIG. 5 illustrates a plan view of an embodiment in which a plurality of ultrasonic element chips are arranged on a flexible substrate with a gap therebetween. [Figure 6] FIGS. 6(a) and (b) illustrate an embodiment of the positional relationship between the ultrasonic element chip and the flexible substrate. [Figure 7] FIGS. 7(a) and (b) illustrate an embodiment in which the ultrasonic element chip is connected to a flexible printed circuit board. [Figure 8] FIG. 8 shows an example of the tip portion of the ultrasonic probe of the present disclosure which is of the convex type. [Figure 9] FIG. 9 shows a perspective view of another example of the tip portion of the ultrasonic probe of the present disclosure which is of the convex type. [Figure 10] FIGS. 10(a) and (b) show an example of switching the ultrasonic probe head of the present disclosure between the linear type and the convex type. [Figure 11] FIG. 11 illustrates a cross-sectional view of the tip portion of the ultrasonic probe of the present disclosure. [Figure 12] FIG. 12 illustrates the ultrasonic diagnostic apparatus of the present disclosure.

Embodiments for Carrying Out the Invention

[0011] 《Ultrasonic Probe Head》 The ultrasonic probe head of this disclosure has a plurality of ultrasonic element chips arranged at intervals on a flexible substrate, and each of the plurality of ultrasonic element chips includes a plurality of piezoelectric MEMS ultrasonic transducers on the substrate.

[0012] The present inventors have realized probes of various shapes, not just linear, convex, and concave, by arranging multiple ultrasonic element chips, each containing multiple piezoelectric MEMS ultrasonic transducers on a substrate, on a flexible substrate, even when using piezoelectric MEMS ultrasonic transducers. Conventionally, only one rigid ultrasonic element array substrate was used and fixed to function as a linear probe. However, by dividing this into multiple ultrasonic element chips and using them together with a flexible substrate, it has become possible to create ultrasonic probe heads of various shapes. As a result, the probe head of this disclosure can be used as a convex, linear, or concave ultrasonic probe, even when using piezoelectric MEMS ultrasonic transducers, and its shape can also be changed to a desired shape.

[0013] Furthermore, it was found that with this configuration, even if the ultrasonic probe head is bent or subjected to impact, direct force does not act between adjacent tips, making it less likely for the piezoelectric thin film to be damaged.

[0014] Figure 1(a) shows a side view of an example of the ultrasonic probe head of the present disclosure, Figure 1(b) shows a top view of an example of the ultrasonic probe head of the present disclosure, and Figure 1(c) shows a bottom view of an example of the ultrasonic probe head of the present disclosure.

[0015] As shown in Figure 1(a), the ultrasonic probe head 100 can be bent into a convex shape because multiple ultrasonic element chips 10 are arranged on a flexible substrate 20 at intervals. Thus, the ultrasonic probe head 100 of this disclosure can have a cross-section that is a polygon made up of straight lines, or a polyhedron made up of planes formed by the ultrasonic element chips 10, and can freely form curves or curved surfaces.

[0016] Figure 1(b) shows a plan view of the ultrasonic probe head 100 as seen from the flexible substrate 20 side (top side) in Figure 1(a), where the flexible substrate 20 has multiple openings 20a. An ultrasonic element tip 10, larger than the openings 20a, is located on the back side of the flexible substrate 20. As in this embodiment, the position of the ultrasonic element tip 10 at the openings 20a allows the ultrasonic waves emitted from the ultrasonic element tip to be effectively propagated from the head.

[0017] Figure 1(c) shows a bottom view of the ultrasonic probe head 100 as seen from the side (bottom) of the multiple ultrasonic element chips 10 in Figure 1(a). Multiple ultrasonic element chips 10 are present on the flexible substrate 20 at intervals. In this embodiment, the ultrasonic element chips 10 are larger than the opening 20a, so the opening 20a is not visible.

[0018] In Figures 1(b) and (c), the ultrasonic element chips 10 are arranged one-dimensionally, but they may also be arranged in multiple rows, with the ultrasonic element chips 10 arranged two-dimensionally on the flexible substrate 20.

[0019] In the ultrasonic probe head 100, the spacing between the multiple ultrasonic element tips 10 may be 0.05 mm or more, 0.1 mm or more, 0.3 mm or more, 0.5 mm or more, 1.0 mm or more, or 3.0 mm or more, and may also be 10.0 mm or less, 5.0 mm or less, 3.0 mm, 2.0 mm, or 1.0 mm. For example, the spacing between tips may be in the range of 0.05 mm to 10.0 mm, or 0.1 mm to 3.0 mm. Not all of the tip spacings need to fall within this range; 50% or more, 60% or more, or 80% or more of the total number of tip spacings may fall within this range.

[0020] Preferably, the ultrasonic probe head 100 does not contain any rigid members in the gaps between the multiple ultrasonic element tips 10 so that its shape can be made convex or the like. However, if a desired shape can be achieved, rubber members or the like may be present in the gaps between the ultrasonic element tips 10.

[0021] Preferably, the ultrasonic probe head 100 can be used without problems even when bent with a curvature R of 100 mm or less, 80 mm or less, 50 mm or less, or 40 mm or less, or with curvature R of 10 mm or more, 20 mm or more, 30 mm or more, or 40 mm or more. For example, the ultrasonic probe head 100 can be used without problems in terms of strength, etc., even if the curvature R is in the range of 10 mm to 100 mm or 20 mm to 50 mm. Furthermore, within this range, the curvature is sufficient for a convex-type ultrasonic probe.

[0022] <Ultrasonic element chip 10> The ultrasonic element chip 10 includes a plurality of piezoelectric MEMS ultrasonic transducers 1 on a substrate 2.

[0023] The ultrasonic element chip 10 may be obtained by cutting an ultrasonic element array substrate, on which piezoelectric MEMS ultrasonic transducers 1 are formed using MEMS on a single substrate 2, using a laser such as stealth dicing, or by mechanical cutting with a dicing saw or the like.

[0024] The ultrasonic element chip 10 can be substantially rectangular in shape, and for example, at least one side may be 0.5 mm or more, 1 mm or more, 2 mm or more, or 3 mm or more, or 10 mm or less, 8 mm or less, or 5 mm or less. For example, at least one side of the ultrasonic element chip 10 may be 0.5 mm to 10 mm or 1 mm to 5 mm. The thickness of the ultrasonic element chip 10 may be 0.05 mm or more, 0.1 mm or more, 0.5 mm or more, or 1 mm or more, or 3 mm or less, 2 mm or less, or 1 mm or less. For example, the thickness of the ultrasonic element chip 10 may be 0.05 mm to 3 mm or 0.1 mm to 1 mm. It is not necessary for at least one side and thickness of all of the ultrasonic element chips 10 to fall within these ranges; 50% or more, 60% or more, or 80% or more of the total number of chips may have at least one side and thickness within these ranges.

[0025] Figure 2 shows a plan view of an example of an ultrasonic element chip 10. Figure 3 shows a portion of the A-A' cross-sectional view of the ultrasonic element chip 10 in Figure 2, and Figure 4 shows a portion of the B-B' cross-sectional view of the ultrasonic element chip 10 in Figure 2. The X, Y, and Z directions in the figures are also referred to as the transverse direction, the vertical direction, and the thickness direction, respectively.

[0026] As shown in Figure 2, each ultrasonic element chip 10 includes a plurality of piezoelectric MEMS ultrasonic transducers 1 on a substrate 2. In the embodiment shown in Figure 2, the plurality of piezoelectric MEMS ultrasonic transducers 1 are arranged one-dimensionally in the lateral direction (X direction), and their upper electrodes 1a are electrically connected by a single upper wiring 3.

[0027] In this disclosure, the plurality of piezoelectric MEMS ultrasonic transducers 1 are not limited to embodiments in which they are arranged one-dimensionally on the ultrasonic element chip 10, but may also be arranged two-dimensionally, for example, in the vertical direction.

[0028] In the embodiment shown in Figure 2, the upper wiring 3 is connected to the upper electrode 1a of the piezoelectric MEMS ultrasonic transducer 1 and can be connected to a flexible printed circuit board or the like through the upper wiring terminal 3a located on the outer edge of the ultrasonic element chip. The lower wiring 4 is connected to the lower electrode 1c of the piezoelectric MEMS ultrasonic transducer 1 and can be connected to a flexible printed circuit board or the like through the lower wiring terminal 4a located on the outer edge of the ultrasonic element chip.

[0029] <Ultrasonic element chip 10 - Piezoelectric MEMS ultrasonic transducer 1> The piezoelectric MEMS ultrasonic transducer 1 is a piezoelectric ultrasonic element formed on a substrate using a MEMS known in the art, such as those described in Patent Documents 4 and 5.

[0030] In the embodiment shown in Figure 2, the piezoelectric MEMS ultrasonic transducer 1 has a shape that is elongated in the vertical direction (Y direction), which is particularly effective when observing deep locations. The larger the area of ​​the ultrasonic transducer, the greater the ultrasonic intensity can be. However, with an ultrasonic transducer that is long in one direction, when attempting to observe shallow locations, there may be a difference in the time it takes for ultrasonic waves to arrive from the observation position, depending on whether they are from a nearby or distant position, which can cause a phase shift in the ultrasonic waves. However, when observing deep locations, such a difference is less likely to occur, so the ultrasonic intensity can be increased by using an ultrasonic transducer that is long in one direction. The same applies when receiving signals; by using an ultrasonic transducer that is long in one direction, the output impedance can be lowered, improving the signal-to-noise ratio.

[0031] The aspect ratio (length in the vertical direction / length in the horizontal direction) of the piezoelectric MEMS ultrasonic transducer 1 may be 3 or more, 5 or more, 10 or more, 15 or more, 20 or more, or 30 or more, and may also be 100 or less, 80 or less, 50 or less, 30 or less, or 20 or less. Note that when multiple piezoelectric MEMS ultrasonic transducers 1 are arranged in the vertical direction (Y direction), the aspect ratio may be calculated as length in the horizontal direction / length in the vertical direction. In the prior art, if the piezoelectric MEMS ultrasonic transducer had an elongated shape, the piezoelectric thin film was easily destroyed when an external force was applied. However, with the configuration of this disclosure, even if the piezoelectric MEMS ultrasonic transducer has an elongated shape, it is less likely to be destroyed, and the ultrasonic output and sensitivity can be increased.

[0032] In the embodiments shown in Figures 3 and 4, the piezoelectric MEMS ultrasonic transducer 1 includes an upper electrode 1a, a piezoelectric thin film 1b, a lower electrode 1c, a vibrating membrane 1d, and an insulating film 1e. The upper electrode 1a is connected to the upper wiring 3, and the upper wiring 3 is connected to the upper electrode 1a of an adjacent piezoelectric MEMS transducer 1. At least the vibrating membrane 1d and the insulating film 1e of the piezoelectric MEMS ultrasonic transducer 1 have optional configurations. Furthermore, the piezoelectric MEMS ultrasonic transducer 1 can have the upper electrode 1a located on the side farther from the substrate 2, and the lower electrode 1c located on the side closer to the substrate 2.

[0033] The upper electrode 1a and the lower electrode 1c can be electrodes known in this field, and may be formed from, for example, a metal thin film. The upper electrode 1a and the lower electrode 1c apply a pulse voltage or AC voltage to the piezoelectric thin film 1b, causing the piezoelectric thin film 1b to expand and contract, thereby vibrating the piezoelectric thin film 1b and the vibrating film 1d.

[0034] Furthermore, the piezoelectric MEMS ultrasonic transducer 1 can also function as a receiving element that receives ultrasonic echoes that are reflected back from the object being measured after being emitted. The ultrasonic echo causes the vibrating membrane 1d to vibrate, and this vibration applies stress to the piezoelectric thin film 1b, generating a voltage between the upper electrode 1a and the lower electrode 1c, which can then be extracted as a received signal.

[0035] Furthermore, the configuration of the upper electrode 1a and the lower electrode 1c is not limited to these configurations. These electrodes only need to be able to vibrate the piezoelectric thin film 1b and the vibrating film 1d by applying a pulse voltage or AC voltage to the piezoelectric thin film 1b to stretch / expand the piezoelectric thin film 1b. In this embodiment, the lower electrode 1c is an individual electrode provided individually on the piezoelectric MEMS ultrasonic transducer 1, and the upper electrode 1a is a common electrode connected across multiple piezoelectric MEMS ultrasonic transducers 1 by upper wiring 3. However, the upper electrode may be an individual electrode and the lower electrode a common electrode.

[0036] The piezoelectric thin film 1b is formed from a piezoelectric material well known in this field. The piezoelectric thin film 1b is formed such that at least a portion of it is covered by the upper electrode 1a and at least a portion of the lower electrode 1c. Examples of piezoelectric materials for the piezoelectric thin film 1b include PZT (lead zirconate titanate), lead titanate (PbTiO3), lead zirconate (PbZrO3), and lead lanthanum titanate ((Pb,La)TiO3).

[0037] The average thickness of the piezoelectric thin film 1b may be 50 μm or less, 30 μm or less, 20 μm or less, 10 μm or less, 5 μm or less, or 3 μm or less, and may be 0.1 μm or more, 0.3 μm or more, 0.5 μm or more, 1 μm or more, or 3 μm or more. For example, the average thickness of the piezoelectric thin film 1b may be 0.1 μm or more and 50 μm or less, or 0.5 μm or more and 20 μm or less.

[0038] The vibrating membrane 1d, together with the piezoelectric thin film 1b, can form a monomorph or bimorph structure and function as an ultrasonic transducer. The vibrating membrane 1d can be a thin film of silica, alumina, zirconia, etc., and may be composed of a two-layer structure, for example, a silica thin film and a zirconia thin film. Here, if the substrate 2 is a silicon substrate, the silica thin film can be formed by thermal oxidation treatment of the substrate surface. In this case, the silica thin film may be formed when grooves 2a are created in the silicon substrate 2. The zirconia thin film can be formed on the silica thin film by a method such as sputtering.

[0039] The average thickness of the vibrating film 1d may be 10 μm or less, 5 μm or less, 3 μm or less, 1 μm or less, 0.8 μm or less, or 0.5 μm or less, and may be 0.05 μm or more, 0.1 μm or more, 0.2 μm or more, 0.3 μm or more, or 0.5 μm or more. The average thickness of the piezoelectric thin film 1b may be, for example, 0.05 μm or more and 10 μm or less, or 0.3 μm or more and 3 μm or less.

[0040] <Ultrasonic element chip 10 - substrate 2> The substrate 2 is the substrate used when forming the piezoelectric MEMS ultrasonic transducer 1 using MEMS, and is, for example, a silicon substrate. It is preferable that grooves 2a are formed in the substrate 2, which makes it easier for the piezoelectric thin film 1b and the vibrating film 1d to vibrate.

[0041] The groove 2a of the substrate 2 can be slightly larger than the piezoelectric thin film 1b of the piezoelectric MEMS ultrasonic transducer 1. For example, the lateral length of the groove 2a of the substrate 2 may be 500 μm or less, 300 μm or less, 200 μm or less, 100 μm or less, 50 μm or less, or 30 μm or less, or 10 μm or more, 30 μm or more, 50 μm or more, or 100 μm or more. The lateral length of the groove 2a may be, for example, 10 μm or more and 500 μm or less, or 30 μm or more and 200 μm or less. The vertical length of the groove 2a can be considered by referring to the aspect ratio of the piezoelectric MEMS ultrasonic transducer 1 described above.

[0042] The average thickness of the main body portion 2b of the substrate 2, excluding the groove portion 2a, may be 1000 μm or less, 800 μm or less, 500 μm or less, 300 μm or less, 150 μm or less, 100 μm or less, 80 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less, or 10 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, 50 μm or more, 100 μm or more, 300 μm or more, or 500 μm or more. The average thickness of the main body portion of the substrate 2 may be, for example, 300 μm or more and 1000 μm or less, or 20 μm or more and 60 μm or less.

[0043] In particular, for relatively large ultrasonic element chips 10, the average thickness of the main body portion 2b when using a silicon substrate may be 80 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less, and may be 10 μm or more, 20 μm or more, 25 μm or more, or 30 μm or more. The average thickness of the main body portion of the silicon substrate may be, for example, 10 μm or more and 80 μm or less, or 20 μm or more and 60 μm or less.

[0044] The silicon substrates used in this field typically have a thickness in the range of 500 μm to 1 mm, and ultrasonic element chips 10 using such silicon substrates do not have flexibility. The inventors have found that by using a silicon substrate with a thickness in the above range, it is possible to provide the ultrasonic element chip 10 with sufficient flexibility to give a convex-type ultrasonic probe curvature and sufficient strength for practical use. Furthermore, in embodiments in which ultrasonic waves are emitted from the substrate 2 side of the ultrasonic element chip 10, it was found that using a thinner substrate is advantageous because it allows for more efficient emission of ultrasonic waves.

[0045] To obtain such an ultrasonic element chip 10, the piezoelectric MEMS ultrasonic transducer 1 may be formed on a thin silicon substrate, or the piezoelectric MEMS ultrasonic transducer 1 may be formed on a thick silicon substrate, and then the silicon substrate may be thinned by polishing the back surface or the like. Alternatively, the silicon substrate may not be thinned and may remain at the normal thickness of a silicon substrate used in the element formation process.

[0046] <Flexible base material 20> The flexible substrate 20 is not particularly limited in type, as long as it can give the ultrasonic probe head 100 of this disclosure various shapes, but for example, a resin film or sheet can be used. In particular, a polyimide film for flexible printed circuit boards may be used as the flexible substrate. Alternatively, resin substrates used in flexible electronics, such as PET (polyethylene terephthalate) or PEN (polyethylene naphthalate), may be used.

[0047] Furthermore, the flexible substrate 20 may be a laminate of multiple layers, one of which may function as an acoustic matching layer, and another may function as an acoustic lens.

[0048] The appropriate average thickness of the flexible substrate 20 varies depending on the material of the flexible substrate and is not particularly limited, but may be, for example, 300 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, 80 μm or less, or 50 μm or less, or 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, or 50 μm or more. The average thickness of the flexible substrate 20 may be, for example, 10 μm or more and 300 μm or less, or 20 μm or more and 50 μm or less.

[0049] As shown in Figure 1(b), the flexible substrate 20 may have multiple openings 20a. In this embodiment, the ultrasonic element tip 10 is located at the position of the openings 20a, allowing the ultrasonic waves emitted from the ultrasonic element tip to be effectively propagated from the head. The flexible substrate 20 and the ultrasonic element tip 10 can be bonded together, for example, with an adhesive.

[0050] Figure 5 illustrates a plan view of an embodiment in which multiple ultrasonic element chips 10 are arranged on a flexible substrate 20 at intervals. As shown in Figure 5, it is preferable that the openings 20a of the flexible substrate 20 are provided at the locations where the piezoelectric thin film 1b of the piezoelectric MEMS ultrasonic transducer 1 of the ultrasonic element chip 10 is present.

[0051] Figures 6(a) and (b) illustrate embodiments of the positional relationship between the ultrasonic element chip 10 and the flexible substrate 20. As shown in Figure 6(a), the ultrasonic element chip 10 can be configured such that the piezoelectric MEMS ultrasonic transducer 1 is located on the flexible substrate 20 side, the substrate 2 is located on the side farther from the flexible substrate 20, and the ultrasonic waves are emitted toward the flexible substrate 20 side. In this case, an acoustic lens 30 can be placed in the opening 20a.

[0052] As shown in Figure 6(b), the ultrasonic element chip 10 can be configured such that the piezoelectric MEMS ultrasonic transducer 1 is located on the flexible substrate 20 side, the substrate 2 is located on the side farther from the flexible substrate 20, and ultrasonic waves are emitted toward the substrate 2 side of the ultrasonic element chip 10. In this embodiment, there does not need to be any openings in the flexible substrate 20. Furthermore, to improve the ultrasonic wave emission efficiency, it is preferable that the substrate 2 has a small thickness. In addition, as shown in Figure 8 of Patent Document 3, an acoustic lens 30 can be placed on the substrate 2, and an acoustic matching layer may be present in the groove portion 2a of the substrate 2.

[0053] <Other components - Acoustic lens 30> As shown in Figure 6(a), the ultrasonic probe head 100 of this disclosure may have an acoustic lens 30 on an opening 20a in a flexible substrate 20, for example, to focus the ultrasonic waves output from the probe and improve resolution. In embodiments where there is no opening 20a in the flexible substrate 20, the material of the flexible substrate 20 can be selected so that the flexible substrate 20 itself functions as an acoustic lens. Alternatively, the acoustic lens may be configured as a cover portion of the ultrasonic probe head, as used in the prior art.

[0054] Acoustic lenses can be those that are well known in this field, and may, for example, be acoustic lenses made of silicone rubber.

[0055] The acoustic lens 30 and the ultrasonic element chip 10 can be bonded together by an adhesive layer, which can also serve as an acoustic matching layer. This reduces the difference in acoustic impedance between the piezoelectric MEMS ultrasonic transducer 1 and the subject, thereby reducing ultrasonic reflection and efficiently directing ultrasonic waves onto the subject.

[0056] <Other components - Flexible printed circuit board 40 and wire bonding 50> Figures 7(a) and 7(b) illustrate an embodiment in which the ultrasonic element chip 10 is connected to the flexible printed circuit board 40. As shown in Figure 7(a), the ultrasonic probe head 100 of this disclosure can transmit and receive electrical signals by connecting the flexible printed circuit board 40 to the upper wiring terminal 3a and lower wiring terminal 4a on the piezoelectric MEMS ultrasonic transducer 1 of the ultrasonic element chip 10.

[0057] The flexible printed circuit board 40 can be one that is well known in this field, for example, a board in which metal wiring is formed on a polyimide film can be used.

[0058] For example, the flexible printed circuit board 40 and the upper wiring terminals 3a and lower wiring terminals 4a can be connected by wire bonding 50. The connection between the flexible printed circuit board 40 and the upper wiring terminals 3a and lower wiring terminals 4a is not limited to wire bonding 50; other well-known connection methods such as anisotropic conductive film (ACF) can be used, and when using wire bonding 50 as a connection method, well-known methods in this field can be adopted.

[0059] As shown in Figures 7(a) and (b), when the ultrasonic element chip 10 and the flexible substrate 20 are arranged as shown in the embodiment of Figure 6(a), and the flexible printed circuit board 40 is connected to the upper wiring terminal 3a and the lower wiring terminal 4a through wire bonding 50 at their joint surface, the connection between the upper wiring terminal 3a and the lower wiring terminal 4a and the flexible printed circuit board 40 is highly secure, regardless of the shape of the ultrasonic probe head 100, and wire bonding 50 breakage and other problems are less likely to occur, which is preferable.

[0060] Ultrasound probe The ultrasonic probe of this disclosure comprises at least an ultrasonic probe head as described above, and a head shape component that constitutes the head shape of the ultrasonic probe head. The head shape component is not particularly limited as long as it can deform the flexible base material of the ultrasonic probe head. The ultrasonic probe of this disclosure may comprise other configurations useful as an ultrasonic probe.

[0061] As the head shape component, the head shape component used in the prior art, such as Patent Document 1, to create a convex shape or the like can be used as is, and may be a linear, convex, or concave type backing material. The head shape component may have a convex shape or the like, or its shape may be changeable, for example, it may be switchable between a linear and a convex shape. If a head shape component with a changeable shape is adopted, and a probe using the probe head of this disclosure is adopted in a portable ultrasound diagnostic device, there is no need to carry two probes, so the ultrasound diagnostic device is extremely advantageous when used outside the hospital, in emergency situations, etc.

[0062] Figure 8 shows an example of a cross-sectional view of the tip portion of an ultrasonic probe 200, including the ultrasonic probe head 100 and a head-shaped component 110 having a convex shape, according to the present disclosure. Figure 9 shows a perspective view thereof. In this ultrasonic probe head 100, openings 20a are present in the flexible substrate 20 at positions corresponding to each ultrasonic element chip 10. A flexible printed circuit board 40 is connected to each ultrasonic element chip 10.

[0063] Figure 10 shows an example of switching between a linear and a convex type ultrasonic probe head according to the present disclosure. As shown in Figure 10, the head shape component 110 supports the center and at least three points at both ends of the ultrasonic probe head 100, and can be a component that changes the shape of the ultrasonic probe head 100 by changing the positional relationship of the support members.

[0064] As shown in Figure 10(a), a central support member 111 that supports the ultrasonic probe head 100 at its center and an end support member 112 that supports the end of the ultrasonic probe head 100 are connected by a wire 113. In this embodiment, as shown in Figure 10(b), the relative positions of the support members are changed by winding the wire 113 on the spool 111a in the central support member 111, thereby forming a curve in the ultrasonic probe head 100. However, by supporting multiple positions other than the center, the ultrasonic probe head 100 may be changed to various shapes.

[0065] The head shape component 110 may be configured to control the shape of the ultrasonic probe head 100 by changing the distance between the support members (111, 112) using a rack and pinion mechanism.

[0066] In the embodiment shown in Figure 10, the head shape component 110 further includes a flexible back surface base material 114 that supports the probe head 100 from the back side. By applying force to such a back surface base material as described above, the head shape can be controlled.

[0067] Figure 11 illustrates a cross-sectional view of the tip portion of the ultrasonic probe when using the ultrasonic probe head of the embodiment described in Figure 10. A sealing member 140 may be present between the housing 120 of the ultrasonic probe 200 and the ultrasonic probe head 100. The sealing member 140 is not particularly limited as long as it can prevent moisture and the like from entering the housing 120, but it may be, for example, silicone rubber.

[0068] Ultrasound diagnostic equipment The ultrasound diagnostic apparatus of this disclosure comprises at least an ultrasound probe, a processing unit for processing signals from the ultrasound probe, and a display device for converting signals from the processing unit into image data and displaying them. The transmission and reception of signals, processing, and control of the ultrasound probe can be carried out by methods well known in the art, such as those described in Patent Documents 2 to 4.

[0069] Figure 12 illustrates an ultrasound diagnostic apparatus of the present disclosure. The ultrasound diagnostic apparatus 1000 of the present disclosure comprises an ultrasound probe 200 and a display device 300, the ultrasound probe 200 and the display device 300 being connected by a cable 400. In this embodiment, the ultrasound diagnostic apparatus 1000 is a portable device, but it may also be a stationary device. In this embodiment, the ultrasound probe 200 and the display device 300 are connected by a cable 400, but they can also be connected wirelessly. A processing unit for processing signals from the ultrasound probe is not shown, but it may be located in the ultrasound probe or in the display device 300. [Explanation of Symbols]

[0070] 1. Piezoelectric MEMS ultrasonic transducer 1a Upper electrode 1b Piezoelectric thin film 1c bottom electrode 1d vibrating membrane 1e insulating film 2 circuit boards 2a Groove 2b Main body part 3. Top wiring 3a Upper wiring terminal 4. Lower wiring 4a Lower wiring terminal 10 Ultrasonic element chips 20 Flexible substrate 20a hole 30 Acoustic Lenses 40 Flexible printed circuit boards 50 Wire Bonding 100 Ultrasonic Probe Heads 110 Head shape component 111 Central support member 111a Spool 112 End support member 113 wire 114 Flexible back base material 120 cabinets 140 Sealing member 200 Ultrasound Probes 300 display device 400 Cable 1000 Ultrasound diagnostic equipment

Claims

1. Multiple ultrasonic element chips are arranged at intervals on a flexible substrate. The flexible substrate has a plurality of openings, and the plurality of ultrasonic element tips are located at the positions of the plurality of openings. An ultrasonic probe head in which each of the plurality of ultrasonic element chips includes a plurality of piezoelectric MEMS ultrasonic transducers on a substrate, and which can be reshaped into a convex, linear, or concave type.

2. The ultrasonic probe head according to claim 1, wherein the shape can be changed by supporting at least three points at the center and both ends of the ultrasonic probe head and changing the positional relationship of the support members.

3. The ultrasonic probe head according to claim 1 or 2, wherein the piezoelectric MEMS ultrasonic transducer includes an upper electrode, a piezoelectric thin film, and a lower electrode in that order, the upper electrode facing the flexible substrate side, and the lower electrode facing the substrate side.

4. The ultrasonic probe head according to claim 3, wherein the piezoelectric MEMS ultrasonic transducers are arranged in one or two dimensions, and in each of the ultrasonic element chips, the upper electrode and the lower electrode are connected by upper wiring and lower wiring to upper wiring terminals and lower wiring terminals provided on the outer edge of the ultrasonic element chip, respectively.

5. The ultrasonic probe head according to any one of claims 1 to 4, wherein at least one side of each of the plurality of ultrasonic element chips is 1 mm to 5 mm and the thickness is 1 mm or less.

6. The ultrasonic probe head according to any one of claims 1 to 5, wherein the spacing between each of the plurality of ultrasonic element chips is in the range of 0.1 mm to 3 mm.

7. The ultrasonic probe head according to any one of claims 1 to 6, wherein each of the gaps between the plurality of ultrasonic element chips does not contain a rigid member.

8. An ultrasonic probe comprising at least an ultrasonic probe head according to any one of claims 1 to 7, and a head shape component that constitutes the head shape of the ultrasonic probe head.

9. An ultrasound diagnostic apparatus comprising at least an ultrasound probe according to claim 8, a processing unit for processing signals from the ultrasound probe, and a display device for converting the signals from the processing unit into an image and displaying it.

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