Ultrasonic transducer array

Abstract

An ultrasonic transducer array (10) comprises: a plurality of units (20) each having a piezoelectric element (21) and a diaphragm (22); a first conductive path (30) electrically connected to each of the diaphragms (22) of the plurality of units (20); and a second conductive path (40) electrically connected to each of electrodes (27) provided on the other main surfaces (25) of the respective piezoelectric elements (21) of the plurality of units (20). The first conductive path (30) has a conductive member (32) disposed on the opposite side from the diaphragm (22) with the piezoelectric element (21) therebetween, and a plurality of first spring members (31) disposed between the respective plurality of diaphragms (22) and the conductive member (32). One end (31A) of each of the plurality of first spring members (31) is in contact with each of the plurality of diaphragms (22), and the other end (31B) of each of the plurality of first spring members (31) is jointly in contact with the conductive member (32).

Description

Ultrasonic Transducer Array

[0001] The present invention relates to an ultrasound transducer array.

[0002] Conventionally, ultrasonic transducers used for transmitting and receiving ultrasonic waves have been known. For example, the ultrasonic transducer described in Patent Document 1 below includes a piezoelectric element, a diaphragm, and a pair of terminals. One of the pair of terminals is electrically connected to one electrode of the piezoelectric element. The other of the pair of terminals is electrically connected to the diaphragm, which is in contact with the other electrode of the piezoelectric element.

[0003] Japanese Patent Application Publication No. 04-187000

[0004] When two or more of the above ultrasonic transducers are arranged on a substrate to form an ultrasonic transducer array, many terminals are densely arranged on one surface of the substrate, which makes wiring and space saving difficult.

[0005] The present invention was completed in view of the above circumstances, and an object of the present invention is to provide an ultrasonic transducer array that can avoid overcrowding of terminals.

[0006] The ultrasonic transducer array of the present invention comprises a plurality of units each having a piezoelectric element having electrodes on one and the other opposing main surfaces, and a vibration plate bonded to the one main surface of the piezoelectric element and electrically connected to the electrodes provided on the one main surface; a first conductive path electrically connected to each of the vibration plates of the plurality of units; and a second conductive path electrically connected to each of the electrodes provided on the other main surface of the piezoelectric element of the plurality of units, wherein the first conductive path has a conductive member arranged on the opposite side of the vibration plate with the piezoelectric element in between, and a plurality of first spring members arranged between each of the plurality of vibration plates and the conductive member, wherein one end of each of the plurality of first spring members contacts the respective plurality of vibration plates, and the other end of each of the plurality of first spring members contacts a common conductive member.

[0007] According to the present invention, by providing the terminal on the common conductive member, it is possible to avoid overcrowding of the terminals compared to the case where a terminal is provided for each of the plurality of first spring members.

[0008] Cross-sectional view showing an ultrasonic transducer array in Example 1. Diagram showing the positional relationship between a piezoelectric element, a vibration plate, a first conductive path, and a second conductive path. Cross-sectional view showing an ultrasonic transducer array in Example 2. Diagram showing the positional relationship between a piezoelectric element, a vibration plate, a first conductive path, and a second conductive path. Cross-sectional view showing an ultrasonic transducer array in Example 3.

[0009] A preferred embodiment of the present invention is shown below.

[0010] [1] An ultrasonic transducer array according to the present invention includes a plurality of units, each unit including a piezoelectric element having electrodes on one and the other opposing principal surfaces, and a vibration plate bonded to the one principal surface of the piezoelectric element and electrically connected to the electrodes on the one principal surface, a first electrical conduction path electrically connected to each of the vibration plates of the plurality of units, and a second electrical conduction path electrically connected to each of the electrodes on the other principal surface of the piezoelectric element of the plurality of units, wherein the first electrical conduction path includes a conductive member disposed on the opposite side of the vibration plate with the piezoelectric element therebetween, and a plurality of first spring members disposed between each of the plurality of vibration plates and the conductive member, wherein one end of each of the plurality of first spring members contacts the respective plurality of vibration plates, and the other end of each of the plurality of first spring members contacts a common conductive member. With this configuration, by providing a terminal on a common conductive member, it is possible to avoid crowding of terminals compared to the case where a terminal is provided for each of the plurality of first spring members. [2] In the ultrasonic transducer array described in [1] above, the second electrical conduction path may include a plurality of second spring members, one end of each of which may contact an electrode provided on the other principal surface of each of the piezoelectric elements. With this configuration, the second electrical conduction path does not need to be connected to the second electrodes of the piezoelectric elements by soldering. This prevents connection problems due to solder peeling and the like. [3] In the ultrasonic transducer array described in [2] above, the second electrical conduction path may include a plurality of rod-shaped members that contact the other end of each of the second spring members opposite the one end, thereby electrically connecting each of the second spring members. With this configuration, the contact state between the second spring members and the rod-shaped members is likely to be stable, thereby preventing connection problems in the second electrical conduction path. [4] In the ultrasonic transducer array described in any one of [1] to [3] above, the second electrical conduction path may extend to the side of the conductive member opposite the piezoelectric elements. With this configuration, a terminal of the second electrical conduction path can be provided on the conductive member opposite the piezoelectric elements. Therefore, it is possible to prevent the terminals of the second conductive path from being crowded together in the region of the conductive member on the piezoelectric element side.[5] In the ultrasonic transducer array described in [4] above, the conductive member may have a through hole formed from the piezoelectric element side to the opposite side of the piezoelectric element, and the second electrical conduction path may extend through the through hole. This configuration allows for a smaller loss of the conductive member compared to when a notch or the like is formed in the conductive member to allow the second electrical conduction path to pass through. [6] The ultrasonic transducer array described in any of [1] to [5] above may have an insulator covering the conductive member, and an opening that partially exposes the conductive member may be formed in the portion of the insulator that covers the opposite side of the conductive member from the piezoelectric element. This configuration allows heat transferred to the conductive member by the first spring member to dissipate into the air through the opening. Therefore, deterioration of the ultrasonic transducer array due to heat from the piezoelectric element can be suppressed.

[0011] <Example 1> Example 1 embodying the present invention will be described in detail below with reference to Figures 1 and 2. The ultrasonic transducer array 10 in this example is used, for example, in a medical or industrial ultrasonic device. The ultrasonic transducer array 10 generates ultrasonic waves when a drive signal is given, and converts the ultrasonic waves into electrical signals when received. The ultrasonic transducer array 10 includes two or more units (referred to as ultrasonic transducers 20) each having a piezoelectric element 21 and a diaphragm 22.

[0012] Each ultrasonic transducer 20 includes a piezoelectric element 21, a vibration plate 22, and a resonator 23. The piezoelectric element 21 is made of PZT (lead zirconate titanate), KNN (potassium sodium niobate), or the like, and is shaped like a substantially circular plate. The piezoelectric element 21 has electrodes 26, 27 on one opposing main surface (referred to as a first surface 24) and the other opposing main surface (referred to as a second surface 25). The first surface 24 is formed on one side in the thickness direction of the piezoelectric element 21, and the second surface 25 is formed on the other side in the thickness direction of the piezoelectric element 21. The first surface 24 and the second surface 25 are concentric circular. The first surface 24 and the second surface 25 are parallel. The area of ​​the first surface 24 is equal to the area of ​​the second surface 25.

[0013] In the following description, the side of each component on which the first surface 24 of the piezoelectric element 21 is formed will be referred to as the upper side, and the side on which the second surface 25 is formed will be referred to as the lower side. The Y axis shown in the drawings is parallel to the thickness direction of the piezoelectric element 21. The X axis shown in the drawings is perpendicular to the thickness direction of the piezoelectric element 21. In the description, the positive side of the X axis will be referred to as the right side, and the negative side of the X axis will be referred to as the left side. The Z axis shown in the drawings is perpendicular to the X and Y axes. In the description, the positive side of the Z axis will be referred to as the front side, and the negative side of the Z axis will be referred to as the rear side.

[0014] The piezoelectric element 21 has a first electrode 26 and a second electrode 27. The first electrode 26 and the second electrode 27 are formed by vapor deposition, plating, sputtering, baking, or the like of gold, silver, copper, tin, or the like. The first electrode 26 and the second electrode 27 are circular. The first electrode 26 is formed on the entire first surface 24 of the piezoelectric element 21. The second electrode 27 is formed on the entire second surface 25 of the piezoelectric element 21.

[0015] The diaphragm 22 is conductive and is made of, for example, a metal plate. The diaphragm 22 is placed on the first surface 24 of the piezoelectric element 21 and bonded thereto with an adhesive or the like (not shown). The diaphragm 22 is electrically connected to the first electrode 26. In a plan view, the diaphragm 22 has a circular shape that is slightly larger than the piezoelectric element 21. The diaphragm 22 is arranged coaxially with the piezoelectric element 21. The outer diameter of the diaphragm 22 is larger than the outer diameter of the piezoelectric element 21. The outer periphery of the diaphragm 22 is a free end, and the ultrasonic transducer 20 is a so-called open type. The diaphragm 22 is more likely to vibrate than the diaphragm of a sealed ultrasonic transducer in which the outer periphery of the diaphragm is fixed.

[0016] The resonator 23 is made of metal and has a conical shape. The resonator 23 is fixed to the center of the upper surface of the diaphragm 22 with an adhesive (not shown). The resonator 23 resonates with the vibration of the diaphragm 22 to generate ultrasonic waves.

[0017] The ultrasonic transducer array 10 includes two or more ultrasonic transducers 20, a case 11, a first electrical conduction path 30, and a second electrical conduction path 40. The ultrasonic transducers 20 are arranged side by side at equal intervals in the left-right direction. The ultrasonic transducers 20 are arranged on the same plane. The ultrasonic transducers 20 have the same configuration, size, and shape.

[0018] The case 11 is made of synthetic resin, and houses the ultrasonic transducer 20 therein and holds the ultrasonic transducer 20. The case 11 protects the ultrasonic transducer 20 so that foreign matter does not come into contact with the ultrasonic transducer 20.

[0019] The case 11 has an insulator 12 arranged below the ultrasonic transducer 20, a peripheral wall 13 surrounding the ultrasonic transducer 20, and an upper wall 14 arranged above the ultrasonic transducer 20. A plurality of openings are formed in the upper wall 14. Ultrasonic waves are transmitted from inside the case 11 to the outside through the openings in the upper wall 14, and also enter the case 11 from the outside.

[0020] The insulator 12 has insulating properties and covers most of the first power transmission path 30 and the second power transmission path 40. The insulator 12 is plate-shaped and extends in the front-rear and left-right directions. An upper surface 12A and a lower surface 12B of the insulator 12 are parallel to the lower surface (second surface 25) of the piezoelectric element 21 and the lower surface of the vibration plate 22. The insulator 12 supports the ultrasonic transducer 20 via a fixing member 15.

[0021] The fixing member 15 is bonded to each of the piezoelectric element 21 and the insulator 12. The fixing member 15 raises the piezoelectric element 21 above the upper surface 12A of the insulator 12. The fixing member 15 supports the outer periphery of the piezoelectric element 21. The fixing member 15 is an adhesive having insulating and elastic properties. The fixing member 15 is made of, for example, rubber or resin mixed with carbon black or calcium carbonate.

[0022] The first power transmission path 30 is electrically connected to each of the vibration plates 22 of the ultrasonic transducers 20. The first power transmission path 30 includes a plurality of first spring members 31 and one conductive member 32.

[0023] Each first spring member 31 is a compression coil spring formed by spirally winding a conductive wire, such as a metal wire. Each first spring member 31 is attached in an elastic orientation in the opposing direction of the diaphragm 22 and the conductive member 32. In the attached state, the first spring member 31 is sandwiched and compressed between the diaphragm 22 and the conductive member 32. An upper end (one end) 31A of each first spring member 31 elastically contacts the lower surface of the diaphragm 22 and is electrically connected to the diaphragm 22. A lower end 31B (the other end) of each first spring member 31 elastically contacts the upper surface 32A of the conductive member 32 and is electrically connected to the conductive member 32.

[0024] The first spring member 31 is in contact with the vicinity of a vibration node of the diaphragm 22. A vibration node is a portion where the amount of displacement in the plate thickness direction when the diaphragm 22 vibrates is smallest or a portion where there is no vibration. The node is uniquely determined by the shapes and materials of the piezoelectric element 21 and the resonator 23.

[0025] The first spring member 31 is inserted into a first hole 16 formed in the insulator 12. The first hole 16 of the insulator 12 penetrates in the vertical direction from the upper surface 12A of the insulator 12 to the upper surface 32A of the conductive member 32. In the attached state, at least half of the lower side of the vertical length dimension of the first spring member 31 is located within the first hole 16 of the insulator 12. This prevents the first spring member 31 from detaching from the insulator 12. In the attached state, the upper portion of the first spring member 31 protrudes above the upper surface 12A of the insulator 12.

[0026] The conductive member 32 has a plate shape with a plate surface that extends in the left-right and front-rear directions. Both the top and bottom surfaces of the conductive member 32 are covered with the insulator 12. In a plan view, the conductive member 32 has a substantially rectangular shape that is longer in the left-right direction than in the front-rear direction. The conductive member 32 is made of a conductive material. For example, the conductive member 32 is formed by punching a metal plate material. The conductive member 32 is disposed below the multiple ultrasonic transducers 20. The conductive member 32 has a size equal to or larger than the arrangement area of ​​all the ultrasonic transducers 20. The plate surface of the conductive member 32 and the plate surface of the vibration plate 22 are parallel to each other. The conductive member 32 has multiple contacts 33 that are electrically connected to the multiple first spring members 31, respectively. The number of contacts 33 is the same as the number of first spring members 31.

[0027] The conductive member 32 is integrally provided with a first terminal 34. The first terminal 34 protrudes to the right from the right edge of the conductive member 32. For example, the first terminal 34 is formed simultaneously with the punching of the conductive member 32. The first terminal 34 is disposed on the same plane as the conductive member 32. The first terminal 34 has a rectangular shape in a plan view. The first terminal 34 protrudes to the right from the right end face of the insulator 12.

[0028] The second electrical conduction path 40 is electrically connected to the second electrodes 27 of the piezoelectric elements 21 of each ultrasonic transducer 20. The second electrical conduction path 40 has a plurality of second spring members 41 and a plurality of plate-shaped members 42.

[0029] Each second spring member 41 is a compression coil spring formed by spirally winding a conductive wire, such as a metal wire. Each second spring member 41 is attached in an elastic orientation in the opposing direction of the piezoelectric element 21 and the plate-shaped member 42. In the attached state, the second spring member 41 is sandwiched and compressed between the piezoelectric element 21 and the plate-shaped member 42. An upper end (one end) 41A of the second spring member 41 elastically contacts the second electrode 27 of the piezoelectric element 21 and is electrically connected to the second electrode 27. A lower end (other end) 41B of the second spring member 41 elastically contacts the upper surface of the plate-shaped member 42 and is electrically connected to the plate-shaped member 42.

[0030] The second spring member 41 is in contact with the vicinity of the outer periphery of the piezoelectric element 21. The second spring member 41 is inserted into the second hole 17 of the insulator 12. The second hole 17 of the insulator 12 penetrates from the upper surface 12A of the insulator 12 to the upper surface of the plate-like member 42. In the attached state, the lower portion of the second spring member 41 is disposed in the second hole 17, and the upper portion of the second spring member 41 protrudes above the upper surface 12A of the insulator 12.

[0031] In the attached state, the compressed length of the first spring member 31 is different from the compressed length of the second spring member 41. In other words, the pressure at which the first spring member 31 contacts the vibration plate 22 is different from the pressure at which the second spring member 41 contacts the piezoelectric element 21. This makes it possible to increase the pressure at which the first spring member 31 contacts the vibration node and decrease the pressure at which the second spring member 41 contacts the piezoelectric element 21 at a location far from the vibration node.

[0032] The plurality of plate-shaped members 42 are arranged below the plurality of second spring members 41, respectively. Both the top and bottom surfaces of the plate-shaped members 42 are covered with the insulator 12. The number of plate-shaped members 42 is the same as the number of second spring members 41. Each plate-shaped member 42 is formed into a plate shape from a conductive material. For example, the plate-shaped members 42 are formed by punching a metal plate material. The plate surface of the plate-shaped member 42 and the second surface 25 of the piezoelectric element 21 are parallel. The plate-shaped member 42 is arranged above and spaced apart from the conductive member 32. The plate-shaped member 42 and the conductive member 32 are insulated by the insulator 12.

[0033] Each plate-shaped member 42 has a generally rectangular shape that is longer in the front-to-rear direction than in the left-to-right direction. The plate-shaped members 42 are the same size and shape. The plate-shaped members 42 are arranged at equal intervals in the left-to-right direction. Each plate-shaped member 42 has a contact 43 that is electrically connected to the second spring member 41. The contact 43 is provided on the rear end side of the upper surface of each plate-shaped member 42. The contact 43 is located at the position of the second hole 17 of the insulator 12. The contact 43 faces the outer edge of the piezoelectric element 21 in the up-down direction.

[0034] The front end of each plate-shaped member 42 protrudes forward from the front surface of the insulator 12. The portion of each plate-shaped member 42 protruding from the insulator 12 constitutes a second terminal 44. The protruding direction of the second terminal 44 is perpendicular to the protruding direction of the first terminal 34. The second terminal 44 has a rectangular shape in a plan view. The second terminals 44 are arranged at equal intervals in the left-right direction. The interval between adjacent second terminals 44 on the left and right is the distance necessary to prevent short-circuiting during high-voltage operation.

[0035] The first terminal 34 and the second terminal 44 are electrical signal input / output terminals. A negative electrode side conductive path (not shown) is connected to the first terminal 34. A positive electrode side conductive path (not shown) is connected to the second terminal 44.

[0036] Next, the operation and effects of the embodiment configured as described above will be described. The ultrasonic transducer array 10 includes a plurality of ultrasonic transducers 20, each having a piezoelectric element 21 and a vibration plate 22, a first electrical conduction path 30, and a second electrical conduction path 40. The piezoelectric element 21 has a first electrode 26 and a second electrode 27 on its opposing first and second surfaces 24 and 25. The vibration plate 22 is bonded to the first surface 24 of the piezoelectric element 21 and electrically connected to the first electrode 26 provided on the first surface 24. The first electrical conduction path 30 is electrically connected to each of the vibration plates 22 of the plurality of ultrasonic transducers 20. The second electrical conduction path 40 is electrically connected to each of the second electrodes 27 of the piezoelectric elements 21 of the plurality of ultrasonic transducers 20. The first electrical conduction path 30 includes a conductive member 32 and a plurality of first spring members 31. The conductive member 32 is disposed on the opposite side of the vibration plate 22, with the piezoelectric element 21 in between. The plurality of first spring members 31 are disposed between each of the plurality of vibration plates 22 and the conductive member 32. The upper end 31A of each of the plurality of first spring members 31 contacts each of the plurality of vibration plates 22, and the lower end 31B of each of the plurality of first spring members 31 contacts a common conductive member 32.

[0037] According to this configuration, by providing the first terminal 34 on the common conductive member 32, it is possible to avoid crowding of terminals compared to when a terminal is provided for each of the multiple first spring members 31. Even when the ultrasonic transducer array 10 is miniaturized, it is possible to prevent the first terminals 34 and the second terminals 44 from being crowded together, thereby preventing short circuits during high-voltage operation. Furthermore, because the first electrical conduction path 30 is electrically connected to the diaphragm 22 by the first spring member 31, it is not necessary to solder the first electrical conduction path 30. This makes it possible to prevent vibration obstruction caused by solder and poor connection due to solder peeling.

[0038] The second electrical conduction path 40 has a plurality of second spring members 41. The upper end 41A of each of the plurality of second spring members 41 is in contact with the second electrode 27 of each of the plurality of piezoelectric elements 21. With this configuration, the second electrical conduction path 40 does not need to be soldered to the second electrode 27 of the piezoelectric elements 21. This makes it possible to prevent poor connection due to solder peeling or the like. Furthermore, heat generated from the piezoelectric elements 21 is quickly transferred to the plate-shaped member 42 by the second spring members 41. This makes it possible to suppress deterioration of the piezoelectric elements 21 due to heat.

[0039] Next, an ultrasonic transducer array 70 according to a second embodiment of the present invention will be described with reference to Figures 3 and 4. The second electrical conduction path 71 of the ultrasonic transducer array 70 of this embodiment differs from that of the first embodiment in that it has a rod-shaped member 72 instead of the plate-shaped member 42 and extends to the lower side of the conductive member 32. Note that the same components as those of the first embodiment are designated by the same reference numerals, and redundant description will be omitted.

[0040] The ultrasonic transducer array 70 according to this embodiment, like the first embodiment, includes two or more ultrasonic transducers 20, a case 11, a first electrical conduction path 30, and a second electrical conduction path 71. Like the first embodiment, each ultrasonic transducer 20 includes a piezoelectric element 21, a diaphragm 22, and a resonator 23, and the first electrical conduction path 30 includes a plurality of first spring members 31 and one electrical conduction member 32.

[0041] The second electrical conduction path 71 includes a plurality of second spring members 41 and a plurality of rod-shaped members 72. The rod-shaped members 72 are arranged below each of the second spring members 41. The number of rod-shaped members 72 is the same as the number of second spring members 41. Each rod-shaped member 72 is formed into a rod shape from a conductive material. For example, the rod-shaped members 72 are metal pins. Each rod-shaped member 72 is electrically connected to each of the second spring members 41 by contacting the lower end 41B of each of the second spring members 41.

[0042] Each rod-shaped member 72 has a long, thin columnar shape extending linearly in the vertical direction. Each rod-shaped member 72 has a main body 73 and a flange 74. The cross section of each rod-shaped member 72 perpendicular to the vertical direction is substantially circular. The main body 73 extends from the upper end 72A to the lower end 72B of the rod-shaped member 72. The outer diameter of the main body 73 is constant from the upper end 72A to the lower end 72B. The flange 74 is located at the middle position of the rod-shaped member 72 in the vertical direction. The outer diameter of the flange 74 is larger than the outer diameter of the main body 73. The outer diameters of the flange 74 and the main body 73 are each the maximum width dimension in the XZ plane. The rod-shaped members 72 are of the same size and shape. The rod-shaped members 72 are arranged at equal intervals in the left-right direction.

[0043] Each rod-shaped member 72 has a contact point 75 with the second spring member 41. The contact point 75 is an upper end 72A of each rod-shaped member 72. The contact point 75 is parallel to the second surface 25 of the piezoelectric element 21. The contact point 75 faces the outer edge of the piezoelectric element 21 in the up-down direction.

[0044] Each of the rod-shaped members 72 is embedded in the insulator 12. The contact 75 of each rod-shaped member 72 is located at the center of the insulator 12 in the vertical direction. The upper portion of each rod-shaped member 72 is embedded in the insulator 12, and the lower portion of each rod-shaped member 72 protrudes downward from the lower surface 12B of the insulator 12. The lower end of each rod-shaped member 72 forms a second terminal 79. The second terminals 79 are arranged at equal intervals in the left-right direction. The interval between adjacent second terminals 79 on the left and right is sufficient to prevent short-circuiting during high-voltage operation.

[0045] The rod-shaped member 72 protrudes in a direction perpendicular to the XZ plane parallel to the arrangement surface of the first terminal 34. This allows the arrangement space for the first terminal 34 and the second terminal 79 to be expanded not only in the horizontal direction but also in the vertical direction, preventing a large number of terminals from being crowded together on the same plane.

[0046] A plurality of through holes 76 are formed in the conductive member 32. Each through hole 76 penetrates the conductive member 32 in the vertical direction from the upper surface 32A to the lower surface 32B. Each through hole 76 is circular in plan view. Each through hole 76 is arranged coaxially with the second hole 17. The central axis of the rod-shaped member 72 and the central axis of the through hole 76 are the same. The inner diameter dimension D1 of each through hole 76 is larger than the outer diameter dimension D2 of the flange portion 74. In other words, the opening area of ​​the through hole 76 is larger than the projected area of ​​the rod-shaped member 72 when the ultrasonic transducer array 70 is viewed from below. This prevents the first conductive path 30 and the second conductive path 71 from coming close to each other, thereby preventing a short circuit during high-voltage operation.

[0047] The distance between the peripheral surface 77 of the through hole 76 and the outer peripheral surface 78 of the rod-shaped member 72 is set to be equal to or greater than the distance that prevents a short circuit during high-voltage operation. This more reliably prevents a short circuit between the first power transmission path 30 and the second power transmission path 71. The distance between the peripheral surface 77 of the through hole 76 and the outer peripheral surface 78 of the rod-shaped member 72 is the shortest distance between the peripheral surface 77 of the through hole 76 and the outer peripheral surface 78 of the rod-shaped member 72 in the XZ plane.

[0048] The second electrical conduction path 71 passes through a through hole 76 in the electrically conductive member 32 and extends to the lower side of the electrically conductive member 32 (the side opposite the piezoelectric element 21). The lower end of the second spring member 41 and the upper end of the rod-shaped member 72 are located within the range of the through hole 76 in the up-down direction.

[0049] As described above, in the present embodiment, similarly to the first embodiment, the first power transmission path 30 has a conductive member 32 and a plurality of first spring members 31, and the plurality of first spring members 31 are disposed between each of the plurality of vibration plates 22 and the conductive member 32, with the upper end 31A of each of the plurality of first spring members 31 contacting each of the plurality of vibration plates 22, and the lower end 31B of each of the plurality of first spring members 31 commonly contacting the conductive member 32. According to this configuration, by providing the first terminal 34 on the common conductive member 32, it is possible to avoid crowding of terminals compared to the case where a terminal is provided for each of the plurality of first spring members 31.

[0050] The second power transmission path 71 also has a plurality of rod-shaped members 72 electrically connected to each of the second spring members 41. With this configuration, the contact state between the second spring members 41 and the rod-shaped members 72 tends to be stable, thereby preventing poor connection of the second power transmission path 71.

[0051] Furthermore, the second electrical conduction path 71 extends to the lower side of the conductive member 32. With this configuration, the second terminal 79 of the second electrical conduction path 71 can be provided below the conductive member 32. Therefore, it is possible to prevent the second terminals 79 from being crowded together in a narrow region above the conductive member 32.

[0052] Furthermore, a through hole 76 is formed in the conductive member 32 from the top to the bottom, and the second conductive path 71 extends through the through hole 76. With this configuration, the missing portion of the conductive member 32 can be made smaller than when a notch or the like is formed in the conductive member 32 to allow the second conductive path 71 to pass through.

[0053] <Example 3> Next, an ultrasonic transducer array 90 according to Example 3 embodying the present invention will be described with reference to Fig. 5. The ultrasonic transducer array 90 of this example differs from Example 2 in that an opening 93 is formed in a lower surface portion 92 of the insulator 12 that covers the lower side of the conductive member 32 (the side opposite the piezoelectric element 21). Note that the same components as in Example 2 are denoted by the same reference numerals, and redundant description will be omitted.

[0054] The ultrasonic transducer array 90 according to this embodiment, similar to the second embodiment, includes two or more ultrasonic transducers 20, a case 11, a first electrical conduction path 30, and a second electrical conduction path 71. Similar to the second embodiment, each ultrasonic transducer 20 includes a piezoelectric element 21, a diaphragm 22, and a resonator 23, the first electrical conduction path 30 includes a plurality of first spring members 31 and one conductive member 32, and the second electrical conduction path 71 includes a plurality of second spring members 41 and a plurality of rod-shaped members 72.

[0055] The insulator 12 has an upper surface portion 91 that covers the upper side of the conductive member 32, and a lower surface portion 92 that covers the lower side of the conductive member 32. The area of ​​the upper surface portion 91 along the XZ plane is larger than the area of ​​the upper surface 32A of the conductive member 32. The upper surface portion 91 has a constant thickness dimension above the conductive member 32. The first hole 16 and the second hole 17 are formed in the upper surface portion 91.

[0056] The lower surface portion 92 has a constant thickness dimension below the conductive member 32. The rod-shaped member 72 is embedded in the lower surface portion 92. A plurality of openings 93 are formed in the lower surface portion 92. The number of openings 93 is the same as the number of ultrasonic transducers 20. The openings 93 are located between adjacent second terminals 79. The area of ​​the lower surface portion 92 along the XZ plane is smaller than the area of ​​the lower surface 32B of the conductive member 32. Each opening 93 partially exposes the lower surface 32B of the conductive member 32 to the space below the insulator 12. This prevents heat from building up inside the case 11.

[0057] As described above, in this embodiment, similar to the second embodiment, by providing the first terminal 34 on the common conductive member 32, it is possible to avoid crowding of terminals compared to the case where a terminal is provided for each of the plurality of first spring members 31. Furthermore, similar to the second embodiment, the second conductive path 71 extends to the lower side of the conductive member 32, so it is possible to avoid crowding of the second terminals 79 in a narrow region above the conductive member 32.

[0058] In the ultrasonic transducer array 90, an opening 93 that partially exposes the conductive member 32 is formed in the lower surface portion 92 of the insulator 12. According to this configuration, heat transferred to the conductive member 32 by the first spring member 31 is dissipated into the air through the opening 93. Therefore, deterioration of the ultrasonic transducer array 90 due to the heat of the piezoelectric elements 21 can be suppressed.

[0059] Other Embodiments The present invention is not limited to the embodiments described above and illustrated in the drawings. The following embodiments, for example, are also within the technical scope of the present invention. (1) In the above embodiments, the multiple vibration plates 22 are spaced apart from one another. This is not a limitation, and a member connecting the vibration plates may be provided. (2) In the above embodiments, the multiple ultrasonic transducers 20 are arranged in a row in the left-right direction. This is not a limitation, and the arrangement of the multiple ultrasonic transducers may be changed as desired. For example, the multiple ultrasonic transducers may be arranged in both the left-right direction and the front-back direction, and may not be arranged at equal intervals. (3) In the above embodiments, the piezoelectric element 21 has a substantially circular plate shape. This is not a limitation, and the piezoelectric element may have a substantially rectangular plate shape, for example. (4) In the above embodiments, the ultrasonic transducer arrays 10, 70, and 90 each have one conductive member 32. This is not a limitation, and the ultrasonic transducer array may have multiple conductive members. In this case, the ultrasonic transducer array may include multiple conductive members, and multiple first spring members may be commonly connected to each conductive member. (5) In the third embodiment, the size and position of the opening 93 are exemplified. The size and position of the opening can be changed as appropriate. (6) In the above embodiment, the electrodes of different polarities formed on the opposing main surfaces (front and back surfaces) of the piezoelectric element 21 are not limited to a configuration in which only one electrode is formed on one main surface, but may also be a so-called folded electrode configuration in which one electrode is formed continuously from one main surface to a portion of the other main surface.

[0060] DESCRIPTION OF SYMBOLS 10, 70, 90...Ultrasonic transducer array 12...Insulator 20...Ultrasonic transducer (unit) 21...Piezoelectric element 22...Vibration plate 24...First surface (one main surface) 25...Second surface (other main surface) 26...First electrode (electrode provided on one main surface) 27...Second electrode (electrode provided on the other main surface) 30...First conductive path 31...First spring member 31A...Upper end (one end of the first spring member) 31B...Lower end (the other end of the first spring member) 32...Conductive member 40, 71...Second conductive path 41...Second spring member 41A...Upper end (one end of the second spring member) 41B...Lower end (the other end of the second spring member) 72...Rod-shaped member 76...Through hole 92...Lower surface portion (portion of the insulator covering the side of the conductive member opposite the piezoelectric element) 93...Opening

Claims

1. An ultrasonic transducer array comprising: a plurality of units each having a piezoelectric element having electrodes on one and the other opposing principal surfaces; and a vibration plate bonded to the one principal surface of the piezoelectric element and electrically connected to the electrodes provided on the one principal surface; a first conductive path electrically connected to each of the vibration plates of the plurality of units; and a second conductive path electrically connected to each of the electrodes provided on the other principal surface of the piezoelectric element of the plurality of units, wherein the first conductive path has a conductive member arranged on the opposite side of the vibration plate with the piezoelectric element therebetween, and a plurality of first spring members arranged between each of the plurality of vibration plates and the conductive member, wherein one end of each of the plurality of first spring members is in contact with each of the plurality of vibration plates, and the other end of each of the plurality of first spring members is in common contact with the conductive member.

2. An ultrasonic transducer array as described in claim 1, wherein the second conductive path has a plurality of second spring members, and one end of each of the plurality of second spring members is in contact with an electrode provided on the other main surface of each of the plurality of piezoelectric elements.

3. An ultrasonic transducer array as described in claim 2, wherein the second conductive path has a plurality of rod-shaped members that are electrically connected to each of the plurality of second spring members by contacting the other end opposite the one end of each of the plurality of second spring members.

4. An ultrasonic transducer array as described in claim 1, wherein the second conductive path extends to the side of the conductive member opposite the piezoelectric element.

5. An ultrasonic transducer array as described in claim 4, wherein a through hole is formed in the conductive member from the piezoelectric element side to the opposite side to the piezoelectric element, and the second conductive path extends through the through hole.

6. An ultrasonic transducer array as described in any one of claims 1 to 5, further comprising an insulator covering the conductive member, and an opening for partially exposing the conductive member is formed in a portion of the insulator covering the side of the conductive member opposite the piezoelectric element.

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