JP2015160104A - Ultrasonic device unit, probe, electronic device and ultrasonic image apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic device unit which can sufficiently attenuate an ultrasonic wave on a back side of a vibration membrane even if the thickness of a substrate is reduced.SOLUTION: An ultrasonic device unit DV comprises: a first substrate 44 which has an element array including a plurality of thin film type ultrasonic transducer elements arranged in the array shape on a first surface and an opening 46 opening on a second surface opposite to the first surface for each of the thin film type ultrasonic transducer elements; and a second substrate 53 which is connected to the second surface of the first substrate 44. The second substrate 53 comprises a through hole having the stretch receiving at least the contour of the element array in a planar view from the thickness direction of the first substrate 44 and continuing from the opening 46.

Description

  The present invention relates to an ultrasonic device unit, and a probe, an electronic apparatus, an ultrasonic imaging apparatus, and the like using the ultrasonic device unit.

  As disclosed in Patent Document 1, an ultrasonic device including an ultrasonic transducer element is generally known. The ultrasonic transducer element includes a substrate having an element array including a plurality of ultrasonic transducer elements arranged in an array on a first surface. Each ultrasonic transducer element includes a vibrating membrane. In forming the vibration film, an opening is formed in the substrate. The opening is opened on the second surface on the back side of the first surface.

JP2013-21604A

  In Patent Document 1, the back plate is bonded to the second surface of the substrate. The back plate closes the opening of the substrate. At this time, a certain type of ultrasonic device is expected to further reduce the thickness of the ultrasonic device. Along with this, as the substrate becomes thinner, the depth of the opening decreases. The distance from the vibration film to the back plate is shortened, and as a result, there is a concern about reflection of ultrasonic waves propagating in the air in the opening. The ultrasonic wave that cannot be attenuated is reflected at the interface of the back plate and acts on the vibration film, which adversely affects the ultrasonic measurement.

  In view of such circumstances, there is a demand for an ultrasonic device unit that can sufficiently attenuate ultrasonic waves on the back side of the vibration film even if the substrate is thinned.

  (1) One aspect of the present invention has an element array including a plurality of thin-film ultrasonic transducer elements arranged in an array on the first surface, and the thin-film ultrasonic transducer elements are arranged for each of the thin-film ultrasonic transducer elements. A first substrate having an opening opening on a second surface on the back side of the first surface; and at least the element in a plan view from the thickness direction of the first substrate, coupled to the second surface of the first substrate The present invention relates to an ultrasonic device unit comprising: a second substrate having a spread opening that accommodates an outline of an array and having a through-hole that is continuous from the opening.

  The thin film type ultrasonic transducer element ultrasonically vibrates the vibrating membrane when transmitting ultrasonic waves. The ultrasonic wave is transmitted from the vibrating membrane to the front side and is emitted from the first surface of the first substrate. At this time, the ultrasonic wave is similarly transmitted from the vibrating membrane to the back side. Ultrasound travels through the opening. Since the opening is continuous with the through hole, the length of the ultrasonic propagation path increases. The ultrasonic wave attenuates as the length of the propagation path increases. Thus, the influence of ultrasonic waves transmitted from the vibrating membrane to the back side is suppressed.

  (2) In the ultrasonic device unit, the second substrate may be a wiring board. A wiring pattern is formed of a conductive material on the wiring board. Arrangement of the conductive material is avoided at the through-hole that continues from the opening. In this way, reflection of ultrasonic waves based on the conductive material is prevented. The influence of miscellaneous signals is suppressed.

  (3) In the ultrasonic device unit, the second substrate may be a reinforcing plate bonded to the second surface of the first substrate. The reinforcing plate is overlaid on the second surface of the first substrate. The reinforcing plate reinforces the rigidity of the first substrate. Here, the second substrate may be bonded to the first substrate with an adhesive for bonding.

  (4) The space of the opening and the through-hole can be filled with a material that causes attenuation to a greater extent than in the air. The attenuation of the ultrasonic wave is promoted by the material filling the opening and the through-hole. As a result, the influence of ultrasonic waves transmitted from the vibrating membrane to the back side is reliably prevented. Thus, if the degree of attenuation increases, it can contribute to shortening of the propagation path of an ultrasonic wave, in other words, to thinning the second substrate.

  (5) The thickness of the material from the thin film type ultrasonic transducer element may be an odd multiple of one quarter of the wavelength of the ultrasonic wave. According to such a structure, even if the ultrasonic wave transmitted from the vibrating membrane to the back side is reflected by the interface of the material, the ultrasonic wave returning to the thin film type ultrasonic transducer element cancels out with the ultrasonic wave from the vibrating membrane. Thus, the influence of ultrasonic waves transmitted from the vibrating membrane to the back side is further effectively suppressed.

  (6) The ultrasonic device unit is separated from the thin-film ultrasonic transducer element by the air layer in contact with the thin-film ultrasonic transducer element in the opening, and closes at least the through-hole. It may further comprise a material layer that causes attenuation to a greater extent than the air in the ultrasonic wave. The attenuation of ultrasonic waves is promoted by the material layer that closes the through hole. As a result, the influence of ultrasonic waves transmitted from the vibrating membrane to the back side is reliably prevented. Thus, if the degree of attenuation increases, it can contribute to shortening of the propagation path of an ultrasonic wave, in other words, to thinning the second substrate.

  (7) The thickness of the air layer from the thin film type ultrasonic transducer element may be an odd multiple of one quarter of the wavelength of the ultrasonic wave. According to such a structure, even if the ultrasonic waves transmitted from the vibration film to the back side are reflected at the interface between the air layer and the material layer, the ultrasonic waves returning to the thin film type ultrasonic transducer element cancel each other out with the ultrasonic waves from the vibration film. Thus, the influence of ultrasonic waves transmitted from the vibrating membrane to the back side is further effectively suppressed.

  (8) The thickness of the material layer from the air layer may be an odd multiple of one quarter of the wavelength of the ultrasonic wave. According to such a structure, even if the ultrasonic wave transmitted through the material layer is reflected at the interface of the material layer, the ultrasonic wave returning to the thin film type ultrasonic transducer element cancels out with the ultrasonic wave from the vibration film. Thus, the influence of ultrasonic waves transmitted from the vibrating membrane to the back side is further effectively suppressed.

  (9) The ultrasonic device unit may be used by being incorporated in a probe. At this time, the probe may include an ultrasonic device unit and a housing that supports the ultrasonic device unit.

  (10) The ultrasonic device unit may be used by being incorporated in an electronic apparatus. In this case, the electronic apparatus can include an ultrasonic device unit and a processing unit that is connected to the ultrasonic device unit and processes the output of the ultrasonic device unit.

  (11) The ultrasonic device unit may be used by being incorporated in an ultrasonic imaging apparatus. At this time, the ultrasonic imaging apparatus is connected to the ultrasonic device unit, the processing unit that processes the output of the ultrasonic device unit and generates an image, and the display that displays the image Apparatus.

1 is an external view schematically showing a specific example of an electronic apparatus according to an embodiment, that is, an ultrasonic diagnostic apparatus. It is an enlarged plan view of an ultrasonic device according to an embodiment. It is sectional drawing of the ultrasonic device unit which concerns on 1st Embodiment along the AA line of FIG. It is a manufacturing process of an ultrasonic device, Comprising: It is a vertical sectional view which shows the material with which an opening part and a through-hole are filled. It is an expanded partial sectional view of the ultrasonic device unit concerning a 2nd embodiment. It is a vertical sectional view of an ultrasonic device unit according to a third embodiment. It is a vertical sectional view of an ultrasonic device unit according to a fourth embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are essential as means for solving the present invention. Not necessarily.

(1) Overall Configuration of Ultrasonic Diagnostic Apparatus FIG. 1 schematically shows a specific example of an electronic apparatus, that is, an ultrasonic diagnostic apparatus (ultrasonic imaging apparatus) 11 according to an embodiment of the present invention. The ultrasonic diagnostic apparatus 11 includes an apparatus terminal (processing unit) 12 and an ultrasonic probe (probe) 13. The apparatus terminal 12 and the ultrasonic probe 13 are connected to each other by a cable 14. The apparatus terminal 12 and the ultrasonic probe 13 exchange electric signals through the cable 14. A display panel (display device) 15 is incorporated in the device terminal 12. The screen of the display panel 15 is exposed on the surface of the device terminal 12. In the device terminal 12, an image is generated based on the ultrasonic wave detected by the ultrasonic probe 13. The imaged detection result is displayed on the screen of the display panel 15.

  The ultrasonic probe 13 has a housing 16. An ultrasonic device unit DV is accommodated in the housing 16. The ultrasonic device unit DV includes an ultrasonic device 17. The ultrasonic device 17 includes an acoustic lens 18. The outer surface of the acoustic lens 18 is formed by a partial cylindrical surface 18a. The acoustic lens 18 is made of, for example, a silicone resin. The acoustic lens 18 has an acoustic impedance close to that of a living body. A window hole 19 is defined in the housing 16. An acoustic lens 18 is disposed in the window hole 19. The outer surface of the acoustic lens 18 is exposed on the surface of the housing 16. The ultrasonic device 17 outputs an ultrasonic wave from the surface and receives a reflected wave of the ultrasonic wave.

  FIG. 2 schematically shows a plan view of the ultrasonic device 17. The ultrasonic device 17 includes a base 21. An element array 22 is formed on the surface (first surface) of the base 21. The element array 22 includes an array of thin film ultrasonic transducer elements (hereinafter referred to as “elements”) 23 arranged in an array. The array is formed of a matrix having a plurality of rows and a plurality of columns. In addition, a staggered arrangement may be established in the array. In the staggered arrangement, the even-numbered element groups 23 need only be shifted by half the row pitch with respect to the odd-numbered element groups 23. The number of elements in one of the odd and even columns may be one less than the number of the other element.

  Each element 23 includes a vibration film 24. In FIG. 2, the outline of the diaphragm 24 is drawn with a dotted line in a plan view in a direction perpendicular to the film surface of the diaphragm 24 (a plan view from the thickness direction of the substrate). A piezoelectric element 25 is formed on the vibration film 24. The piezoelectric element 25 includes an upper electrode 26, a lower electrode 27, and a piezoelectric film 28. A piezoelectric film 28 is sandwiched between the upper electrode 26 and the lower electrode 27 for each element 23. These are stacked in the order of the lower electrode 27, the piezoelectric film 28 and the upper electrode 26. The ultrasonic device 17 is configured as a single ultrasonic transducer element chip (substrate).

  A plurality of first conductors 29 are formed on the surface of the base 21. The first conductors 29 extend parallel to each other in the row direction of the array. One first conductor 29 is assigned to each row of the elements 23. One first conductor 29 is commonly connected to the piezoelectric film 28 of the elements 23 arranged in the row direction of the array. The first conductor 29 forms the upper electrode 26 for each element 23. Both ends of the first conductor 29 are connected to a pair of lead wires 31 respectively. The lead wires 31 extend parallel to each other in the column direction of the array. Accordingly, all the first conductors 29 have the same length. Thus, the upper electrode 26 is connected in common to the elements 23 of the entire matrix. The first conductor 29 can be formed of iridium (Ir), for example. However, other conductive materials may be used for the first conductor 29.

  A plurality of second conductors 32 are formed on the surface of the base 21. The second conductors 32 extend parallel to each other in the column direction of the array. One second conductor 32 is assigned to each element 23 in one row. One second conductor 32 is disposed in common on the piezoelectric film 28 of the elements 23 arranged in the column direction of the array. The second conductor 32 forms a lower electrode 27 for each element 23. For example, a laminated film of titanium (Ti), iridium (Ir), platinum (Pt), and titanium (Ti) can be used for the second conductor 32. However, other conductive materials may be used for the second conductor 32.

  Energization of the element 23 is switched for each column. Linear scan and sector scan are realized according to such switching of energization. Since the elements 23 in one column output ultrasonic waves simultaneously, the number of columns, that is, the number of rows in the array, can be determined according to the output level of the ultrasonic waves. For example, the number of lines may be set to about 10 to 15 lines. In the figure, five lines are drawn without illustration. The number of columns in the array can be determined according to the spread of the scanning range. The number of columns may be set to 128 columns or 256 columns, for example. In the figure, there are omitted and 8 columns are drawn. The roles of the upper electrode 26 and the lower electrode 27 may be interchanged. That is, while the lower electrode is commonly connected to the elements 23 of the entire matrix, the upper electrode may be commonly connected to the elements 23 for each column of the array.

  The outline of the base body 21 has a first side 21a and a second side 21b that are partitioned by a pair of parallel lines and face each other. One line of the first terminal array 33 a is arranged between the first side 21 a and the outline of the element array 22. One line of the second terminal array 33 b is arranged between the second side 21 b and the outline of the element array 22. The first terminal array 33a can form one line parallel to the first side 21a. The second terminal array 33b can form one line parallel to the second side 21b. The first terminal array 33 a includes a pair of upper electrode terminals 34 and a plurality of lower electrode terminals 35. Similarly, the second terminal array 33 b includes a pair of upper electrode terminals 36 and a plurality of lower electrode terminals 37. Upper electrode terminals 34 and 36 are connected to both ends of one lead-out wiring 31, respectively. The lead wiring 31 and the upper electrode terminals 34 and 36 may be formed symmetrically on a vertical plane that bisects the element array 22. Lower electrode terminals 35 and 37 are connected to both ends of one second conductor 32, respectively. The second conductor 32 and the lower electrode terminals 35 and 37 may be formed symmetrically on a vertical plane that bisects the element array 22. Here, the outline of the base 21 is formed in a rectangular shape. The outline of the base 21 may be square or trapezoidal.

  A first flexible printed wiring board (hereinafter referred to as “first wiring board”) 38 is connected to the base body 21. The first wiring board 38 covers the first terminal array 33a. Conductive lines, that is, first signal lines 39 are formed at one end of the first wiring board 38 individually corresponding to the upper electrode terminal 34 and the lower electrode terminal 35. The first signal lines 39 are individually faced and joined to the upper electrode terminal 34 and the lower electrode terminal 35, respectively. Similarly, the base 21 is covered with a second flexible printed wiring board (hereinafter referred to as “second wiring board”) 41. The second wiring board 41 covers the second terminal array 33b. Conductive lines, that is, second signal lines 42 are formed at one end of the second wiring board 41 so as to individually correspond to the upper electrode terminal 36 and the lower electrode terminal 37. The second signal line 42 is individually faced and joined to the upper electrode terminal 36 and the lower electrode terminal 37.

(2) Configuration of Ultrasonic Device Unit According to First Embodiment As shown in FIG. 3, the base 21 includes a substrate (first substrate) 44 and a coating film 45. A coating film 45 is formed on the entire surface of the substrate 44. An opening 46 is formed in the substrate 44 for each element 23. The openings 46 are arranged in an array with respect to the substrate 44. Each opening 46 opens on the back surface (second surface) for each element 23. The contour of the region where the opening 46 is disposed corresponds to the contour of the element array 22. A partition wall 47 is defined between two adjacent openings 46. Adjacent openings 46 are partitioned by a partition wall 47. The wall thickness of the partition wall 47 corresponds to the interval between the openings 46. The partition wall 47 defines two wall surfaces in a plane extending parallel to each other. The wall thickness corresponds to the distance between the two wall surfaces. That is, the wall thickness can be defined by the length of a perpendicular line sandwiched between the wall surfaces perpendicular to the wall surfaces. The substrate 44 may be formed of a silicon substrate, for example.

The covering film 45 includes a silicon oxide (SiO ₂ ) layer 48 stacked on the surface of the substrate 44 and a zirconium oxide (ZrO ₂ ) layer 49 stacked on the surface of the silicon oxide layer 48. The coating film 45 is in contact with the opening 46. Thus, a part of the coating film 45 forms the vibration film 24 corresponding to the outline of the opening 46. The vibration film 24 is a portion of the coating film 45 that can vibrate in the thickness direction of the substrate 44 because it faces the opening 46. The film thickness of the silicon oxide layer 48 can be determined based on the resonance frequency.

  A lower electrode 27, a piezoelectric film 28, and an upper electrode 26 are sequentially stacked on the surface of the vibration film 24. The piezoelectric film 28 can be formed of, for example, lead zirconate titanate (PZT). Other piezoelectric materials may be used for the piezoelectric film 28. Here, the piezoelectric film 28 completely covers the second conductor 32 under the first conductor 29. A short circuit between the first conductor 29 and the second conductor 32 can be avoided by the action of the piezoelectric film 28.

  An acoustic matching layer 51 is laminated on the surface of the base 21. The acoustic matching layer 51 covers the element array 22. The film thickness of the acoustic matching layer 51 is determined according to the resonance frequency of the vibration film 24. For example, a silicone resin film can be used for the acoustic matching layer 51. The acoustic lens 18 is disposed on the acoustic matching layer 51. The acoustic lens 18 is in close contact with the surface of the acoustic matching layer 51 on the plane behind the partial cylindrical surface 18a. The acoustic lens 18 is bonded to the base 21 by the action of the acoustic matching layer 51. The generatrix of the partial cylindrical surface 18 a is positioned in parallel to the first conductor 29. The curvature of the partial cylindrical surface 18a is determined according to the focal position of the ultrasonic wave transmitted from the one row of elements 23 connected to the single second conductor 33.

  A reinforcing plate (second substrate) 53 as a backing material is coupled to the back surface of the base 21. The reinforcing plate 53 is formed in a flat plate shape. The back surface of the base 21 is overlaid on the surface of the reinforcing plate 53. A through hole 54 is formed in the reinforcing plate 53. The surface of the reinforcing plate 53 is joined to the back surface of the base body 21. In such joining, the reinforcing plate 53 may be bonded to the base 21 with an adhesive. The reinforcing plate 53 reinforces the rigidity of the base body 21. Due to the function of the reinforcing plate 53, a good flatness is secured on the surface of the base 21. The reinforcing plate 53 can include, for example, a rigid base material. Such a substrate may be formed of a metal material such as 42 alloy (iron nickel alloy).

  The through-hole 54 has a width that accommodates at least the outline of the element array 22 in plan view from the thickness direction of the base 21. The through hole 54 continues from the opening 46 of the element 23 included in the element array 22. Here, the opening 46 and the through-hole 54 are filled with air. The thickness of the air from the vibration film 24 is set to an odd multiple of one quarter (λ / 4) of the wavelength λ of the ultrasonic wave. Such air thickness can be set based on the thickness of the substrate 44 and the reinforcing plate 53.

  The ultrasonic device unit DV includes a wiring board 56. The wiring board 56 is coupled to the ultrasonic device 17. The back surface of the reinforcing plate 53 is overlaid on the surface of the wiring board 56. The ultrasonic device 17 may be fixed to the wiring board 56 with a resin material. A wiring pattern 57 is formed on the wiring substrate 56. The first wiring board 38 and the second wiring board 41 of the ultrasonic device 17 are connected to the wiring pattern 57. The wiring pattern 57 includes a first conductive pad 58a and a second conductive pad 58b. The first conductive pads 58 a and the second conductive pads 58 b are formed on the surface of the wiring board 56. The individual first conductive pads 58 a and the second conductive pads 58 b are arranged corresponding to the individual first signal lines 39 and the second signal lines 42. The first conductive pad 58a and the second conductive pad 58b may be formed of a conductive material such as copper. Corresponding first signal lines 39 and second signal lines 42 are joined to the respective first conductive pads 58a and second conductive pads 58b.

  A first connector 59 a and a second connector 59 b are disposed on the back surface of the wiring board 56. The first connector 59a is connected to the first conductive pad 58a by a via 61a. The second connector 59b is connected to the second conductive pad 58b by a via 61b. The vias 61 a and 61 b penetrate from the front surface to the back surface of the wiring board 56. The cable 14 is formed by wirings 62a and 62b connected to the first connector 59a and the second connector 59b, respectively.

(3) Operation of Ultrasonic Diagnostic Device Next, the operation of the ultrasonic diagnostic device 11 will be briefly described. A pulse signal is supplied to the piezoelectric element 25 in transmitting ultrasonic waves. The pulse signal is supplied to the element 23 for each column through the lower electrode terminals 35 and 37 and the upper electrode terminals 34 and 36. In each element 23, an electric field acts on the piezoelectric film 28 between the lower electrode 27 and the upper electrode 26. The piezoelectric film 28 vibrates at an ultrasonic frequency. The vibration of the piezoelectric film 28 is transmitted to the vibration film 24. In this way, the vibrating membrane 24 vibrates ultrasonically. As a result, a desired ultrasonic beam is emitted toward an object (for example, the inside of a human body).

  The ultrasonic reflected wave vibrates the vibration film 24. The ultrasonic vibration of the vibration film 24 causes the piezoelectric film 28 to vibrate at a desired frequency. A voltage is output from the piezoelectric element 25 according to the piezoelectric effect of the piezoelectric element 25. In each element 23, a potential is generated between the upper electrode 26 and the lower electrode 27. The potential is output as an electrical signal from the lower electrode terminals 35 and 37 and the upper electrode terminals 34 and 36. In this way, ultrasonic waves are detected.

  Transmission and reception of ultrasonic waves are repeated. As a result, linear scan and sector scan are realized. When the scan is completed, an image is formed based on the digital signal of the output signal. The formed image is displayed on the screen of the display panel 15.

  As described above, the vibration film 24 vibrates ultrasonically when ultrasonic waves are transmitted. The ultrasonic waves are transmitted from the vibration film 24 to the front side and emitted from the surface of the substrate 44. At this time, the ultrasonic wave is similarly transmitted from the vibrating membrane 24 to the back side. The ultrasonic wave is transmitted through the air in the opening 46. Since the opening 46 is continuous with the through-hole 54, the length of the ultrasonic wave propagation path increases. The ultrasonic wave attenuates as the length of the propagation path increases. Thus, the influence of ultrasonic waves transmitted from the vibration film 24 to the back side is suppressed.

  The opening 46 and the through hole 54 may be filled with a specific material. The material is desired to cause attenuation to a greater extent than in the air for ultrasound. A resin material can be used as such a material. The attenuation of ultrasonic waves is promoted by the action of the material. As a result, the influence of ultrasonic waves transmitted from the vibration film 24 to the back side is reliably prevented. Thus, if the degree of attenuation increases, it can contribute to shortening of the propagation path of an ultrasonic wave, in other words, reducing the thickness of the reinforcing plate 53. In filling the material, for example, as shown in FIG. 4, the flowable material 63 may be poured into the through hole 54 and the opening 46 after the reinforcing plate 53 is attached. When the poured material 63 is cured, the opening 46 and the through-hole 54 can be filled with the material 63. If the wiring substrate 56 is stacked prior to curing, the material 63 can function as an adhesive. In addition, the remaining air (bubbles) in the through hole 54 can be avoided.

The thickness t ₁ of the material from the vibration film 24 may be set to an odd multiple of ¼ (λ / 4) of the ultrasonic wavelength λ. The thickness of such a material can be set based on the thickness of the substrate 44 and the reinforcing plate 53. According to such a structure, even if the ultrasonic wave transmitted from the vibration film 24 to the back side is reflected at the interface of the material 63, the ultrasonic waves returning to the element 23 cancel each other with the ultrasonic waves from the vibration film 24. Thus, the influence of ultrasonic waves transmitted from the vibration film 24 to the back side is further effectively suppressed.

(4) Ultrasonic Device Unit According to Second Embodiment As shown in FIG. 5, in the ultrasonic device 17, an air layer 65 in contact with the vibration film 24 in the opening 46 may be formed. At this time, the through hole 54 only needs to be blocked by the material layer 66. The material layer 66 is separated from the vibration film 24 by an air layer 65. It is desirable that the material layer 66 be formed of a material that causes attenuation to a greater degree than the air in the ultrasonic wave. A resin material can be used as such a material. The attenuation of ultrasonic waves is promoted by the action of the material layer 66. As a result, the influence of ultrasonic waves transmitted from the vibration film 24 to the back side is reliably prevented. Thus, if the degree of attenuation increases, it can contribute to shortening of the propagation path of an ultrasonic wave, in other words, reducing the thickness of the reinforcing plate 53. A material layer 66 may be formed in the through hole 54 of the reinforcing plate 53 prior to the bonding of the reinforcing plate 53 to the substrate 44.

The thickness t ₂ of the air layer 65 from the vibration film 24 may be set to an odd multiple of 1 (lambda / 4) of the quarter of the wavelength lambda of the ultrasonic wave. According to such a structure, even if the ultrasonic wave transmitted from the vibration film 24 to the back side is reflected at the interface between the air layer 65 and the material layer 66, the ultrasonic waves returning toward the element 23 cancel each other with the ultrasonic waves from the vibration film 24. . Thus, the influence of ultrasonic waves transmitted from the vibration film 24 to the back side is further effectively suppressed.

Similarly, the thickness t ₃ of the material layer 66 from the air layer 65 may be set to an odd multiple of ¼ (λ / 4) of the ultrasonic wavelength λ. According to such a structure, even if the ultrasonic wave transmitted through the material layer 66 is reflected at the interface of the material layer 66, the ultrasonic waves returning toward the element 23 cancel each other with the ultrasonic waves from the vibration film 24. Thus, the influence of ultrasonic waves transmitted from the vibration film 24 to the back side is further effectively suppressed. In addition, the material layer 66 may enter the opening 46 according to the thickness of the air layer 65.

(5) Ultrasonic Device Unit According to Third Embodiment FIG. 6 schematically shows a configuration of an ultrasonic device unit DVa according to the third embodiment. In the ultrasonic device unit DVa, a through hole 68 is formed in the wiring board 67 in addition to the through hole 54 of the reinforcing plate 53. The through-hole 68 has a width that accommodates at least the outline of the element array 22 in plan view from the thickness direction of the wiring board 67. The through hole 68 is continuous with the through hole 54 of the reinforcing plate 53. The through-holes 68 and 54 may be filled with air, or may be filled with a material that causes attenuation to a greater extent than in air. Since the opening 46 is continuous with the through holes 54 and 68, the length of the ultrasonic wave propagation path is increased. The ultrasonic wave attenuates as the length of the propagation path increases. Thus, the influence of ultrasonic waves transmitted from the vibration film 24 to the back side is suppressed. When filled with a material, attenuation of ultrasonic waves is promoted with a material filling the through holes 54 and 68. Similarly to the above, the thickness of the material from the vibration film 24 may be set to an odd multiple of one quarter (λ / 4) of the wavelength λ of the ultrasonic wave. According to such a structure, even if the ultrasonic wave transmitted from the vibration film 24 to the back side is reflected at the interface of the material, the ultrasonic waves returning to the element 23 cancel each other with the ultrasonic waves from the vibration film 24. Thus, the influence of ultrasonic waves transmitted from the vibration film 24 to the back side is further effectively suppressed.

  As described above, an air layer in contact with the vibrating membrane 24 may be formed in the opening 46 and the through holes 54 and 68. The through-hole 68 may be blocked with a material layer separated from the vibrating membrane 24 by an air layer. The thickness of the air layer from the vibrating membrane 24 may be set to an odd multiple of one quarter (λ / 4) of the wavelength λ of the ultrasonic wave. The thickness of the material layer from the air layer may be set to an odd multiple of ¼ of the ultrasonic wavelength λ (λ / 4). Depending on the thickness of the air layer, the material layer may enter the through hole 54 or the opening 46. Other configurations are the same as those of the ultrasonic device unit DV described above.

(6) Ultrasonic Device Unit According to Fourth Embodiment FIG. 7 schematically shows a configuration of an ultrasonic device unit DVb according to the fourth embodiment. In the ultrasonic device unit DVb, the base 21 is received directly by the wiring board (wiring board) 67. In other words, the reinforcing plate 53 is omitted when the ultrasonic device 17 and the wiring board 67 are coupled. Similar to the above, the through hole 68 is formed in the wiring board 67. The through hole 68 continues from the opening 46. Other configurations are the same as those of the ultrasonic device units DV and DVa described above.

  Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Therefore, all such modifications are included in the scope of the present invention. For example, a term described with a different term having a broader meaning or the same meaning at least once in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings. In addition, the ultrasonic diagnostic apparatus 11, the apparatus terminal 12, the ultrasonic probe 13, the display panel 15, the housing 16, the base body 21, the element 23, the first and second wiring boards 38 and 41, the acoustic matching layer 51, and the acoustic lens 52. Such a configuration and operation are not limited to those described in the present embodiment, and various modifications are possible.

  DESCRIPTION OF SYMBOLS 11 Ultrasonic imaging device (ultrasonic diagnostic apparatus) as an electronic device, 12 Processing part (apparatus terminal), 13 Probe (ultrasonic probe), 15 Display apparatus (display panel), 16 Case, 17 Ultrasonic device, 22 Element array, 23 Thin-film ultrasonic transducer element, 44 First substrate (substrate), 46 Opening, 53 Second substrate (reinforcing plate), 54 Through-hole, 65 Air layer, 66 Material layer, 67 Wiring substrate, 68 Through-hole, DV ultrasonic device unit, DVa ultrasonic device unit, DVb ultrasonic device unit.

Claims (11)

An element array including a plurality of thin film type ultrasonic transducer elements arranged in an array is provided on the first surface, and each thin film type ultrasonic transducer element is provided on a second surface on the back side of the first surface. A first substrate having an opening to be opened;
A through-hole coupled to the second surface of the first substrate and having a spread to accommodate at least the outline of the element array in a plan view from the thickness direction of the first substrate and continuing from the opening. A second substrate;
An ultrasonic device unit comprising:   2. The ultrasonic device unit according to claim 1, wherein the second substrate is a wiring board.   2. The ultrasonic device unit according to claim 1, wherein the second substrate is a reinforcing plate bonded to the second surface of the first substrate.   The ultrasonic device unit according to any one of claims 1 to 3, wherein the space of the opening and the through-hole is filled with a material that causes attenuation to a greater extent than the air in the ultrasonic wave. A featured ultrasonic device unit.   5. The ultrasonic device unit according to claim 4, wherein the thickness of the material from the thin film ultrasonic transducer element is an odd multiple of one quarter of the wavelength of the ultrasonic wave. .   The ultrasonic device unit according to any one of claims 1 to 3, wherein an air layer in contact with the thin film type ultrasonic transducer element in the opening, and the air layer from the thin film type ultrasonic transducer element. The ultrasonic device unit further comprising: a material layer that is separated, closes at least the through hole, and causes attenuation of ultrasonic waves to a greater degree than in the air.   7. The ultrasonic device unit according to claim 6, wherein the thickness of the air layer from the thin film type ultrasonic transducer element is an odd multiple of one quarter of the wavelength of the ultrasonic wave. unit.   The ultrasonic device unit according to claim 6 or 7, wherein the thickness of the material layer from the air layer is an odd multiple of one quarter of the wavelength of the ultrasonic wave.   A probe comprising: the ultrasonic device unit according to claim 1; and a housing that supports the ultrasonic device unit.   An electronic device comprising: the ultrasonic device unit according to claim 1; and a processing unit connected to the ultrasonic device unit and processing an output of the ultrasonic device unit. machine.   The ultrasonic device unit according to claim 1, a processing unit connected to the ultrasonic device unit, processing an output of the ultrasonic device unit, and generating an image, and the image An ultrasonic imaging apparatus comprising: a display device that displays

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