WO2022210887A1

WO2022210887A1 - Ultrasonic probe head, ultrasonic probe, and ultrasonic diagnostic apparatus

Info

Publication number: WO2022210887A1
Application number: PCT/JP2022/016021
Authority: WO
Inventors: 真理酒井; 学西脇
Original assignee: 国立大学法人山形大学
Priority date: 2021-03-31
Filing date: 2022-03-30
Publication date: 2022-10-06
Also published as: JPWO2022210887A1

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

Ultrasound Probe Head, Ultrasound Probe, and Ultrasound Diagnostic Device

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

An ultrasound diagnostic device is an inspection device that uses ultrasound to examine the inside of the body and structures. Using the ultrasonic probe of this inspection device, ultrasonic waves are transmitted from the body surface to the inside of the body, from the inner surface of the circulatory system and organs to the inside of the body, and from the surface of the structure to the inside of the structure. and the presence or absence of defects, etc., and make a diagnosis. Since the displayed images appear to move in real time, it is possible to perform treatment while confirming the position of the lesion, to observe blood flow dynamics, etc., and because it is a non-invasive technique, it is widely used in the medical field. It is

There are linear type, sector type, convex type, concave type, etc. for ultrasonic probes, and these types are selected according to the purpose of observation and the observation site. For example, the linear type is used for examination of tissues positioned shallow from the body surface, and the convex type is used for examination of tissues positioned deep from the body surface.

Patent document 1 shows an example of conventional technology of a convex ultrasonic probe. The ultrasonic element of such an ultrasonic probe is formed by cutting a piezoelectric ceramic sandwiched between electrodes into strips.

Also, in recent years, ultrasonic probes using piezoelectric MEMS ultrasonic transducers (pMUT: Piezoelectric Micromachined Ultrasonic Transducers) as ultrasonic elements have been developed. Such an ultrasonic probe can greatly reduce the size of the ultrasonic elements and increase the element density. Patent Documents 2-4 disclose such ultrasonic probes. Further, for details of the MEMS for manufacturing this, reference can be made to Patent Documents 4 and 5, for example.

JP-A-8-79895 JP 2014-146883 A JP 2011-259274 A JP 2016-018835 A Japanese Patent Publication No. 2006-516368

As described in Patent Documents 2 to 4, in an ultrasonic probe using a piezoelectric MEMS ultrasonic transducer as an ultrasonic element, the substrate forming the ultrasonic element is a flat substrate such as a silicon substrate. is a linear ultrasonic probe. Moreover, the ultrasonic probes described in these documents have a problem of low reliability because the piezoelectric thin film composed of a very thin brittle material is broken when bent or subjected to impact.

The present disclosure provides a novel ultrasonic probe head that can realize not only linear and convex probes but also probes of various shapes and that is highly reliable.

The present inventors have found that the above problems can be solved by the present disclosure having the following aspects.
<<Aspect 1>>
wherein a plurality of ultrasonic element chips are spaced apart on a flexible substrate, and each of said plurality of ultrasonic element chips includes a plurality of piezoelectric MEMS ultrasonic transducers on a substrate. probe head.
<<Aspect 2>>
The ultrasonic probe head according to aspect 1, wherein the flexible base material has a plurality of apertures, and the plurality of ultrasonic element chips are present at the positions of the plurality of apertures. .
<<Aspect 3>>
The piezoelectric MEMS ultrasonic transducer includes an upper electrode, a piezoelectric thin film, and a lower electrode in this order, the upper electrode facing the flexible base and the lower electrode facing the substrate. 3. The ultrasonic probe head according to

aspect

1 or 2.
<<Aspect 4>>
The piezoelectric MEMS ultrasonic transducers are arranged one-dimensionally or two-dimensionally, and in each of the ultrasonic element chips, the upper electrode and the lower electrode are connected to the ultrasonic element by upper wiring and lower wiring, respectively. The ultrasonic probe head according to aspect 3, wherein the upper wiring terminal and the lower wiring terminal provided on the outer edge of the chip are connected.
<<Aspect 5>>
The ultrasonic probe head according to any one of aspects 1 to 4, wherein each of the plurality of ultrasonic element chips has at least one side of 1 mm to 5 mm and a thickness of 1 mm or less.
<<Aspect 6>>
The ultrasonic probe head according to any one of aspects 1 to 5, wherein each interval between the plurality of ultrasonic element chips is in the range of 0.1 mm to 3 mm.
<<Aspect 7>>
7. The ultrasonic probe head according to any one of aspects 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 the ultrasonic probe head according to any one of aspects 1 to 7 and a head-shaped component forming a head shape of the ultrasonic probe head.
<<Aspect 9>>
An ultrasonic diagnostic apparatus comprising at least the ultrasonic probe according to aspect 8, a processing unit that processes a signal from the ultrasonic probe, and a display device that converts the signal from the processing unit into an image and displays the image.

FIG. 1(a) shows a side view of an example 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. (c) shows a bottom view of an exemplary ultrasound probe head of the present disclosure; FIG. 2 shows a plan view of an example of an ultrasonic element chip. FIG. 3 shows a part of the A-A' cross-sectional view of the ultrasonic element chip of FIG. FIG. 4 shows a part of the B-B' cross-sectional view of the ultrasonic element chip of FIG. FIG. 5 illustrates a plan view of an embodiment in which a plurality of ultrasonic element chips are spaced apart on a flexible substrate. FIGS. 6A and 6B illustrate embodiments of the positional relationship between the ultrasonic element chip and the flexible base material. FIGS. 7(a) and (b) illustrate an embodiment in which the ultrasonic element chip is connected to a flexible printed circuit board. FIG. 8 shows an example of the tip portion of the ultrasonic probe of the present disclosure, which is of convex type. FIG. 9 shows a perspective view of another example of the tip portion of the ultrasonic probe of the present disclosure, which is of convex type. FIGS. 10A and 10B show an example of switching the ultrasonic probe head of the present disclosure between a linear type and a convex type. FIG. 11 illustrates a cross-sectional view of the distal portion of the ultrasound probe of the present disclosure. FIG. 12 illustrates an ultrasound diagnostic apparatus of the present disclosure.

《Ultrasonic Probe Head》
In the ultrasonic probe head of the present disclosure, a plurality of ultrasonic element chips are arranged on a flexible substrate at intervals, and each of the plurality of ultrasonic element chips includes a plurality of piezoelectric MEMS ultrasonic waves. A transducer is included on the substrate.

The present inventors have found that even when piezoelectric MEMS ultrasonic transducers are used, by arranging a plurality of ultrasonic element chips each including a plurality of piezoelectric MEMS ultrasonic transducers on a substrate on a flexible base material, , linear type, convex type, concave type, etc., but also various shapes of probes have been realized. In the past, only one rigid ultrasonic element array substrate was used, and this was fixed and used as a linear type. By using it, it became possible to make the ultrasonic probe head into various shapes. As a result, even if the probe head of the present disclosure uses a piezoelectric MEMS ultrasonic transducer, the ultrasonic probe can be used as a convex type, a linear type, a concave type, etc., and can be changed to a desired shape. became.

In addition, with such a configuration, even if the ultrasonic probe head is bent or impacted, no direct force acts between the adjacent chips, so it was found that the piezoelectric thin film is less likely to be destroyed. .

FIG. 1(a) shows a side view of an example 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. (c) shows a bottom view of an exemplary ultrasound probe head of the present disclosure;

As shown in FIG. 1A, the ultrasonic probe head 100 has a plurality of ultrasonic element chips 10 arranged on a flexible base material 20 at intervals, so that it can be bent into a convex shape. ing. In this way, the ultrasonic probe head 100 of the present disclosure can be a polygon whose cross-section is made up of straight lines, or can be a polyhedron made up of planes by the ultrasonic element chip 10, and can be curved or curved at will. A curved surface can be constructed.

FIG. 1(b) shows a plan view of the ultrasonic probe head 100 viewed from the flexible base 20 side (upper side) in FIG. 1(a). Apertures 20a are present. The ultrasonic element chip 10, which is larger than the opening 20a, exists on the back side of the flexible base material 20. As shown in FIG. Since the ultrasonic element chip 10 is present at the position of the opening 20a as in this embodiment, the ultrasonic waves oscillated from the ultrasonic element chip can be effectively propagated from the head.

FIG. 1(c) shows a bottom view of the ultrasonic probe head 100 seen from the side (lower side) of the plurality of ultrasonic element chips 10 in FIG. 1(a). A plurality of ultrasonic element chips 10 are present at intervals. In this embodiment, the ultrasonic element chip 10 is larger than the aperture 20a, so the aperture 20a is not visible.

1(b) and 1(c), the ultrasonic element chips 10 are arranged one-dimensionally. may be placed in

In the ultrasonic probe head 100, the distance between the plurality of ultrasonic element chips 10 is 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. 10.0 mm or less, 5.0 mm or less, 3.0 mm, 2.0 mm, or 1.0 mm. For example, the tip spacing may be in the range of 0.05 mm to 10.0 mm, or 0.1 mm to 3.0 mm. Not all tip spacings need fall within such ranges, and 50% or more, 60% or more, or 80% or more of the total tip spacings may fall within such ranges.

It is preferable that the ultrasonic probe head 100 does not include rigid members in the gaps between the plurality of ultrasonic element chips 10 so that the shape thereof can be made into a convex shape or the like. However, a rubber member or the like may exist in the gap between the ultrasonic element chips 10 as long as a desired shape can be obtained.

The curvature R of the ultrasonic probe head 100 is preferably 100 mm or less, 80 mm or less, 50 mm or less, or 40 mm or less, and can be used without problems even if it is bent at 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 even if the curvature R is in the range of 10 mm to 100 mm or 20 mm to 50 mm. Also, within this range, the curvature is sufficient for a convex ultrasonic probe.

<Ultrasonic element chip 10>
An ultrasonic element chip 10 includes a plurality of piezoelectric MEMS ultrasonic transducers 1 on a substrate 2 .

The ultrasonic element chip 10 is formed by cutting an ultrasonic element array base material, in which the piezoelectric MEMS ultrasonic transducer 1 is formed by MEMS on one substrate 2, by laser cutting such as stealth dicing, or by mechanical cutting using a dicing saw or the like. etc., may be obtained.

The ultrasonic element chip 10 can have a substantially rectangular parallelepiped shape. Alternatively, it may be 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 may be 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 that at least one side and all of the thickness of the ultrasonic element chip 10 fall within such a range, and 50% or more, 60% or more, or 80% or more of the total number of chips have one side and thickness within such a range. It can be thickness.

FIG. 2 shows a plan view of an example of one ultrasonic element chip 10. FIG. 3 shows a part of the AA' cross-sectional view of the ultrasonic element chip 10 of FIG. 2, and FIG. 4 is a part of the BB' cross-sectional view of the ultrasonic element chip 10 of FIG. showing the part. Note that the X direction, Y direction, and Z direction in the drawings are also referred to as the horizontal direction, vertical direction, and thickness direction, respectively.

As shown in FIG. 2, the ultrasonic element chips 10 each include a plurality of piezoelectric MEMS ultrasonic transducers 1 on the substrate 2 . In the embodiment of FIG. 2, a 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 one upper wiring 3. It is

In the present disclosure, the plurality of piezoelectric MEMS ultrasonic transducers 1 are not limited to the embodiment in which they are arranged one-dimensionally on the ultrasonic element chip 10, but are arranged two-dimensionally, for example, in the vertical direction. Piezoelectric MEMS ultrasonic transducers 1 may be arranged.

In the embodiment shown in FIG. 2, the upper wiring 3 is connected to the upper electrode 1a of the piezoelectric MEMS ultrasonic transducer 1, and is connected to a flexible printed circuit board or the like through upper wiring terminals 3a on the outer edge of the ultrasonic element chip. be able to. 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 lower wiring terminals 4a on the outer edge of the ultrasonic element chip.

<Ultrasonic element chip 10-Piezoelectric MEMS ultrasonic transducer 1>
The piezoelectric MEMS ultrasonic transducer 1 is a piezoelectric ultrasonic element formed on a substrate by means of MEMS well known in the art, such as those described in US Pat.

In the embodiment shown in FIG. 2, the piezoelectric MEMS ultrasonic transducer 1 has a shape elongated in the vertical direction (Y direction), which is particularly effective when observing deep positions. The larger the area of the ultrasonic transducer, the greater the intensity of the ultrasonic wave. There is a difference in the time required for arrival of ultrasonic waves from a position close to and that from a position far away, which may cause a phase shift in the ultrasonic waves. However, when observing a deep position, such a difference is less likely to occur, so the intensity of ultrasonic waves can be increased by using a transducer that is long in one direction. The same is true when receiving a signal, and by using a vibrator that is long in one direction, the output impedance can be lowered and the S/N ratio can be improved.

The aspect ratio (longitudinal length/lateral length) 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, 100 or less, It may be 80 or less, 50 or less, 30 or less, or 20 or less. Note that the aspect ratio may be calculated as the length in the horizontal direction/the length in the vertical direction, for example, when a plurality of piezoelectric MEMS ultrasonic transducers 1 are arranged in the vertical direction (Y direction). In the prior art, if the piezoelectric MEMS ultrasonic transducer has an elongated shape, the piezoelectric thin film is easily destroyed when an external force is applied. Even if it has an elongated shape, it is difficult to break, and it has become possible to increase the output and sensitivity of ultrasonic waves.

In the embodiment shown in FIGS. 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 film 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 the piezoelectric MEMS transducer 1 adjacent thereto. At least the vibrating film 1d and the insulating film 1e of the piezoelectric MEMS ultrasonic transducer 1 are optional. In addition, the piezoelectric MEMS ultrasonic transducer 1 can have the upper electrode 1 a positioned farther from the substrate 2 and the lower electrode 1 c positioned closer to the substrate 2 .

For the upper electrode 1a and the lower electrode 1c, well-known electrodes in this field can be used, and for example, they may be formed of a metal thin film. When the upper electrode 1a and the lower electrode 1c apply a pulse voltage or an alternating voltage to the piezoelectric thin film 1b, the piezoelectric thin film 1b is stretched/extended to vibrate the piezoelectric thin film 1b and the vibrating film 1d.

It should be noted that the piezoelectric MEMS ultrasonic transducer 1 can also operate as a receiving element that receives ultrasonic echoes that are emitted ultrasonic waves that are reflected back from the object to be measured. The ultrasonic echo vibrates the vibrating membrane 1d, 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 be extracted as a received signal.

Moreover, the configurations of the upper electrode 1a and the lower electrode 1c are not limited to these configurations, and these electrodes expand and contract the piezoelectric thin film 1b by applying a pulse voltage or an alternating voltage to the piezoelectric thin film 1b. It suffices if the piezoelectric thin film 1b and the vibrating film 1d can be vibrated. In this embodiment, the lower electrode 1c is an individual electrode that is individually provided on the piezoelectric MEMS ultrasonic transducer 1, and the upper electrode 1a is a common electrode that is connected across the plurality of piezoelectric MEMS ultrasonic transducers 1 by the upper wiring 3. However, the upper electrode may be the individual electrode, and the lower electrode may be the common electrode.

The piezoelectric thin film 1b is formed of a piezoelectric thin film well known in this field. The piezoelectric thin film 1b is formed so as to cover at least a portion of the upper electrode 1a and at least a portion of the lower electrode 1c. Examples of the piezoelectric material of the piezoelectric thin film 1b include PZT (lead zirconate titanate), lead titanate (PbTiO ₃ ), lead zirconate (PbZrO ₃ ), lead lanthanum titanate ((Pb, La)TiO ₃ ), and the like. can be mentioned.

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. Alternatively, it may be 3 μm or more. The average thickness of the piezoelectric thin film 1b may be, for example, 0.1 μm or more and 50 μm or less, or 0.5 μm or more and 20 μm or less.

The vibrating film 1d can form a monomorph structure or a bimorph structure together with the piezoelectric thin film 1b, and can function as an ultrasonic vibrator. A thin film of silica, alumina, zirconia, or the like can be used as the vibrating film 1d. For example, it may have a two-layer structure of a silica thin film and a zirconia thin film. Here, when the substrate 2 is a silicon substrate, the silica thin film can be formed by thermally oxidizing the substrate surface. In this case, the thin silica film may be formed when the grooves 2a are formed in the silicon substrate 2. FIG. A zirconia thin film can be formed on a silica thin film by a method such as sputtering.

The average thickness of the diaphragm 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, or 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.

<Ultrasonic element chip 10 - substrate 2>
The substrate 2 is a substrate for forming the piezoelectric MEMS ultrasonic transducer 1 by MEMS, and is, for example, a silicon substrate. A groove 2a is preferably formed in the substrate 2, so that the piezoelectric thin film 1b and the vibrating film 1d are easily vibrated.

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 longitudinal length of the groove 2a can be considered with reference to the aspect ratio of the piezoelectric MEMS ultrasonic transducer 1 mentioned above.

The average thickness of the body portion 2b of the substrate 2 other than the groove portion 2a is 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. 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 body portion of the substrate 2 may be, for example, 300 μm or more and 1000 μm or less, or may be 20 μm or more and 60 μm or less.

In particular, in the relatively large ultrasonic element chip 10, the average thickness of the 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, or 10 μm or more. , 20 μm or more, 25 μm or more, or 30 μm or more. The average thickness of the body portion of the silicon substrate may be, for example, between 10 μm and 80 μm, or between 20 μm and 60 μm.

A silicon substrate used in this field usually has a thickness in the range of 500 μm to 1 mm, and the ultrasonic element chip 10 using such a silicon substrate does not have flexibility. The present inventors have found that by using a silicon substrate having a thickness within the range described above, it is possible to obtain an ultrasonic wave with a degree of flexibility that provides a sufficient curvature as a convex ultrasonic probe and a practically sufficient strength. It has been found to be applied to the device chip 10. Also, in the embodiment in which ultrasonic waves are transmitted to the substrate 2 side of the ultrasonic element chip 10, it is advantageous to use a thin substrate because ultrasonic waves can be transmitted efficiently. I understood it.

In order 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. After forming the acoustic wave transducer 1, the silicon substrate may be thinned by, for example, polishing the silicon substrate from the back side. Alternatively, the thickness of the silicon substrate used in the element forming process may be kept as it is, without thinning the silicon substrate.

<Flexible base material 20>
The type of the flexible base material 20 is not particularly limited as long as the ultrasonic probe head 100 of the present disclosure can be made into various shapes, but for example, a resin film or sheet can be used. In particular, a polyimide film for a flexible printed circuit board may be used as the flexible base material. Moreover, you may use the resin base material utilized by flexible electronics, such as PET (polyethylene terephthalate) and PEN (polyethylene naphthalate).

Also, the flexible base material 20 may be a laminate of a plurality of layers, one of which may function as an acoustic matching layer, and the other layer may function as an acoustic lens. good too.

A suitable average thickness of the flexible substrate 20 varies depending on the material of the flexible substrate, and is not particularly limited. 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.

As shown in FIG. 1(b), the flexible base material 20 may have a plurality of openings 20a. Since the ultrasonic element chip 10 is present at the position of the opening 20a as in this embodiment, the ultrasonic waves oscillated from the ultrasonic element chip can be effectively propagated from the head. The flexible base material 20 and the ultrasonic element chip 10 can be adhered with an adhesive, for example.

FIG. 5 illustrates a plan view of an embodiment in which a plurality of ultrasonic element chips 10 are spaced apart and arranged on a flexible substrate 20 . As shown in FIG. 5, the opening 20a of the flexible base material 20 is preferably provided at a position where the piezoelectric thin film 1b of the piezoelectric MEMS ultrasonic transducer 1 of the ultrasonic element chip 10 exists.

6(a) and (b) illustrate an embodiment of the positional relationship between the ultrasonic element chip 10 and the flexible base material 20. FIG. As shown in FIG. 6(a), the piezoelectric MEMS ultrasonic transducer 1 is positioned on the flexible base 20 side, the substrate 2 is positioned farther from the flexible base 20, and the ultrasonic waves are flexibly transmitted. The ultrasonic element chip 10 can be configured so as to transmit toward the base material 20 side. In this case, an acoustic lens 30 can be arranged in the aperture 20a.

As shown in FIG. 6B, the piezoelectric MEMS ultrasonic transducer 1 is positioned on the flexible base 20 side, the substrate 2 is positioned on the far side from the flexible base 20, and the ultrasonic wave is transmitted to the ultrasonic wave. The ultrasonic element chip 10 can be configured to transmit toward the substrate 2 side of the element chip 10 . In this embodiment, there may be no perforations in the flexible substrate 20 . Moreover, it is preferable that the thickness of the substrate 2 is small in order to improve the transmission efficiency of the ultrasonic waves. Furthermore, as described in FIG. 8 of Patent Document 3, an acoustic lens 30 can be arranged on the substrate 2, and an acoustic matching layer may exist in the groove 2a of the substrate 2. FIG.

<Other Configurations - Acoustic Lens 30>
As shown in FIG. 6A, the ultrasonic probe head 100 of the present disclosure focuses ultrasonic waves output from the probe on, for example, an aperture 20a of a flexible base material 20 to improve resolution. of acoustic lenses 30 . Also, in embodiments in which the flexible substrate 20 does not have apertures 20a, the material of the flexible substrate 20 can be selected such that the flexible substrate 20 itself functions as an acoustic lens. . The acoustic lens may also be configured as a cover portion of the ultrasound probe head, as used in the prior art.

A well-known acoustic lens in this field can be adopted, for example, it may be an acoustic lens made of silicone rubber.

The acoustic lens 30 and the ultrasonic element chip 10 can be bonded with an adhesive layer, and the adhesive layer can also serve as an acoustic matching layer. As a result, the difference in acoustic impedance between the piezoelectric MEMS ultrasonic transducer 1 and the subject can be reduced, the reflection of ultrasonic waves can be reduced, and the ultrasonic waves can be efficiently incident on the subject.

<Other Configurations - Flexible Printed Board 40 and Wire Bonding 50>
7A and 7B illustrate an embodiment in which the ultrasonic element chip 10 is connected to the flexible printed circuit board 40. FIG. As shown in FIG. 7A, the ultrasonic probe head 100 of the present disclosure includes a flexible printed board 40, upper wiring terminals 3a and lower wiring terminals 4a in the piezoelectric MEMS ultrasonic transducer 1 of the ultrasonic element chip 10. can be connected to send and receive electrical signals.

For the flexible printed board 40, one well known in this field can be adopted. For example, a board in which metal wiring is formed on a polyimide film can be used.

For example, the flexible printed board 40, the upper wiring terminal 3a and the lower wiring terminal 4a can be connected by wire bonding 50. The connection between the flexible printed board 40 and the upper wiring terminal 3a and the lower wiring terminal 4a is not limited to the wire bonding 50, and a known connection method such as an anisotropic conductive film (ACF) may be used. and, when wire bonding 50 is used as the connection method, any method known in the art can be employed.

As shown in FIGS. 7A and 7B, the ultrasonic element chip 10 and the flexible substrate 20 are arranged as shown in the embodiment of FIG. When the flexible printed board 40 is connected to the upper wiring terminal 3a and the lower wiring terminal 4a through the wire bonding 50, the upper wiring terminal 3a and the lower wiring terminal 4a can be connected regardless of the shape of the ultrasonic probe head 100. This is preferable because the safety of the connection with the flexible printed circuit board 40 is high and disconnection of the wire bonding 50 is less likely to occur.

《Ultrasonic Probe》
The ultrasonic probe of the present disclosure includes at least the ultrasonic probe head as described above and a head-shaped constituent member that forms the head shape of the ultrasonic probe head. The head-shaped component is not particularly limited as long as it can deform the flexible base material of the ultrasonic probe head. The ultrasound probes of the present disclosure can have other configurations useful as ultrasound probes.

As the head shape constituent member, it is possible to use the head shape constituent member used to make the head shape such as a convex shape in the prior art such as Patent Document 1 as it is. It may be a concave backing material. The head-shaped component may have a shape such as a convex shape, or may have a changeable shape, for example, may be switchable between a linear shape and a convex shape. When adopting a head-shaped component whose shape type can be changed and adopting a probe using the probe head of the present disclosure in a portable ultrasonic diagnostic apparatus, there is no need to carry two probes. Ultrasound diagnostic equipment is extremely advantageous when used outside hospitals, when used for emergencies, and the like.

FIG. 8 shows an example of a cross-sectional view of a tip portion of an ultrasonic probe 200 including the ultrasonic probe head 100 of the present disclosure and a head-shaped component 110 having a convex shape. Moreover, FIG. 9 has shown the perspective view. This ultrasonic probe head 100 has openings 20 a in the flexible base material 20 at positions corresponding to the respective ultrasonic element chips 10 . A flexible printed circuit board 40 is connected to each ultrasonic element chip 10 .

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

As shown in FIG. 10A, a wire 113 connects a center support member 111 that supports the ultrasonic probe head 100 at the center and an end support member 112 that supports the end of the ultrasonic probe head 100 . . In this embodiment, as shown in FIG. 10(b), the wire 113 is wound by the spool 111a on the central support member 111 to change the positional relationship of the support members and form a curve in the ultrasonic probe head 100. However, the ultrasound probe head 100 may be transformed into a variety of shapes by supporting multiple locations other than the central portion.

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.

In the embodiment shown in FIG. 10, the head-shaped component 110 further includes a flexible back substrate 114 that supports the probe head 100 from the back side. The head shape can be controlled by applying force to such a back substrate as described above.

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

《Ultrasound diagnostic device》
An ultrasonic diagnostic apparatus of the present disclosure includes at least the above-described ultrasonic probe, a processing unit that processes signals from the ultrasonic probe, and a display device that converts the signals from the processing unit into image data and displays the image data. Transmission, reception and processing of signals and control of the ultrasound probe can be performed by methods well known in the art, such as those described in Patent Documents 2-4.

FIG. 12 illustrates an ultrasonic diagnostic apparatus of the present disclosure. An ultrasound diagnostic apparatus 1000 of the present disclosure includes an ultrasound probe 200 and a display device 300 , and the ultrasound probe 200 and display device 300 are connected by a cable 400 . In this embodiment, the ultrasonic diagnostic apparatus 1000 is a portable apparatus, but may be a stationary apparatus. Moreover, in this embodiment, the ultrasonic probe 200 and the display device 300 are connected by a cable 400, but they can be connected wirelessly. A processing unit that processes signals from the ultrasound probe is not shown, but may reside in the ultrasound probe or may reside in the display device 300 .

1 Piezoelectric MEMS ultrasonic transducer 1a Upper electrode 1b Piezoelectric thin film

1c Lower electrode

1d Vibration film 1e Insulating film 2 Substrate 2a Groove 2b Body portion 3 Upper wiring 3a Upper wiring terminal 4 Lower wiring 4a Lower wiring terminal 10 Ultrasonic element chip 20 Flexible flexible substrate 20a aperture 30 acoustic lens 40 flexible printed substrate 50 wire bonding 100 ultrasonic probe head 110 head-shaped component 111 central support member 111a spool 112 end support member 113 wire 114 flexible back substrate 120 housing 140 Sealing member 200 Ultrasonic probe 300 Display device 400 Cable 1000 Ultrasonic diagnostic device

Claims

wherein a plurality of ultrasonic element chips are spaced apart on a flexible substrate, and each of said plurality of ultrasonic element chips includes a plurality of piezoelectric MEMS ultrasonic transducers on a substrate. probe head.
2. The ultrasonic probe according to claim 1, wherein said flexible base material has a plurality of apertures, and said plurality of ultrasonic element chips are present at positions of said plurality of apertures. head.
The piezoelectric MEMS ultrasonic transducer includes an upper electrode, a piezoelectric thin film, and a lower electrode in this order, the upper electrode facing the flexible base and the lower electrode facing the substrate. 3. The ultrasonic probe head of claim 1 or 2, comprising:
The piezoelectric MEMS ultrasonic transducers are arranged one-dimensionally or two-dimensionally, and in each of the ultrasonic element chips, the upper electrode and the lower electrode are connected to the ultrasonic element by upper wiring and lower wiring, respectively. 4. The ultrasonic probe head of claim 3, connected to upper wiring terminals and lower wiring terminals provided on the outer edge of the chip.
The ultrasonic probe head according to any one of claims 1 to 4, wherein each of the plurality of ultrasonic element chips has at least one side of 1 mm to 5 mm and a thickness of 1 mm or less.
The ultrasonic probe head according to any one of claims 1 to 5, wherein each interval between the plurality of ultrasonic element chips ranges from 0.1 mm to 3 mm.
The ultrasonic probe head according to any one of claims 1 to 6, wherein each gap between the plurality of ultrasonic element chips does not contain a rigid member.
An ultrasonic probe comprising at least the ultrasonic probe head according to any one of claims 1 to 7, and a head-shaped component forming a head shape of the ultrasonic probe head.
9. An ultrasonic diagnostic apparatus comprising at least the ultrasonic probe according to claim 8, a processing section that processes a signal from the ultrasonic probe, and a display device that converts the signal from the processing section into an image and displays the image.