Ultrasonic device, ultrasonic diagnostic apparatus

Abstract

The present invention relates to an ultrasonic device and an ultrasonic diagnostic apparatus. An ultrasonic device that is mounted using a flip-chip method and can obtain desired characteristics is provided. The ultrasonic device includes: a first substrate including a first surface on which a first electrode connected to a piezoelectric element is disposed; a second substrate including a second surface on which a second electrode is disposed; an intermediate substrate disposed between the first substrate and the second substrate and including a third surface joined to the first surface and a fourth surface facing the second surface; and an adhesive portion. The intermediate substrate has a through hole penetrating from the third surface to the fourth surface and a third electrode provided in the through hole and connected to the first electrode. The second electrode is connected to the third electrode and is electrically connected to the first electrode via the third electrode. A plurality of the adhesive portions are provided in an island shape separated from each other between the second substrate and the intermediate substrate, and at least one of the adhesive portions is provided so as to surround the third electrode.

Description

Technical Field

[0001] The present invention relates to an ultrasonic device and an ultrasonic diagnostic apparatus including the ultrasonic device. Background Art

[0002] Conventionally, an ultrasonic diagnostic apparatus using an ultrasonic transducer for a probe has been known. For example, Patent Document 1 discloses an ultrasonic diagnostic apparatus including an ultrasonic device obtained by arranging a plurality of ultrasonic transducers in a matrix in a probe.

[0003] According to this document, connection terminals are provided on the surface of the ultrasonic device on the ultrasonic emission side, and a flexible substrate is connected to the connection terminals to supply a drive pulse signal via the flexible substrate. In addition, a rigid first reinforcing plate is bonded and fixed to the back surface of the ultrasonic device to increase the rigidity of the ultrasonic device. The flexible substrate for obtaining electrical connection is connected to a connector on the back side of the ultrasonic device by being bent or overlapped.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-92592

[0005] Since the flexible substrate is difficult to handle, there are problems such as poor mounting yield and difficulty in automation, and thus, research has been conducted to replace it with a rigid substrate. Specifically, connection pads are provided on the first reinforcing plate on the back surface of the ultrasonic device, and a rigid substrate provided on the back side of the first reinforcing plate is mounted by flip-chip bonding to obtain electrical connection. In this case, except for the bonding portion between the electrodes of the rigid substrate and the connection bumps of the ultrasonic device, the entire surface is generally filled with an NCP (Non Conductive Paste) such as an epoxy adhesive.

[0006] However, if the entire surface between the ultrasonic device and the rigid substrate is bonded with NCP, there is a technical problem of affecting the characteristics of the ultrasonic transducer. Specifically, the frequency of the ultrasonic wave emitted by the ultrasonic transducer changes. On the other hand, without NCP, it is difficult to ensure rigidity, and in addition, since the bonding portion including the connection bumps is exposed to the air, there is a technical problem that migration due to moisture intrusion is inevitable.

[0007] That is, there is a need for an ultrasonic device and an ultrasonic diagnostic apparatus that use flip-chip bonding and can obtain desired characteristics (including rigidity). Summary of the Invention

[0008] One aspect of the present application relates to an ultrasonic device including: a first substrate including a first surface on which a piezoelectric element and a first electrode connected to the piezoelectric element are disposed; a second substrate including a second surface on which a second electrode connected to a control circuit is disposed; an intermediate substrate disposed between the first substrate and the second substrate and including a third surface bonded to the first surface and a fourth surface facing the second surface; and an adhesive portion bonding the second substrate and the intermediate substrate. The intermediate substrate has a through hole penetrating from the third surface to the fourth surface and a third electrode disposed in the through hole and connected to the first electrode. The second electrode is connected to the third electrode and is electrically connected to the first electrode via the third electrode. The adhesive portions are provided in a plurality of island-like shapes separated from each other between the second substrate and the intermediate substrate, and at least one of the adhesive portions is provided to surround the third electrode.

[0009] The ultrasonic diagnostic apparatus according to the present application includes the above ultrasonic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 The external view of the ultrasonic diagnostic apparatus according to Embodiment 1.

[0011] Figure 2 The top view of the ultrasonic device.

[0012] Figure 3 The cross-sectional view around the ultrasonic element.

[0013] Figure 4 The cross-sectional view around the connection pad.

[0014] Figure 5 The cross-sectional view around the adhesive portion.

[0015] Figure 6 The flowchart of the manufacturing method of the ultrasonic device.

[0016] Figure 7A The cross-sectional view of one aspect during the manufacturing process.

[0017] Figure 7B The cross-sectional view of one aspect during the manufacturing process.

[0018] Figure 8 The top view of the ultrasonic device according to Embodiment 2.

[0019] REFERENCE MARK DESCRIPTION

[0020] 2: Electrode; 3: Piezoelectric body; 4: Electrode; 5: Piezoelectric element; 6: Diaphragm; 7: Ultrasonic element; 7a to 7d: Element rows; 10: Main body; 11: First substrate; 12: Cable; 13: Probe; 14: Opening; 15: Display unit; 16: Control substrate; 17: Housing part; 18: Acoustic lens; 19: Element array area; 20: Ultrasonic device; 21: Intermediate substrate; 22: Ultrasonic substrate; 22a: Ultrasonic substrate; 25, 26: Through holes; 27, 28: First electrodes; 31: Second substrate; 37, 38: Second electrodes; 41: First wiring; 42: Second wiring; 51: First surface; 52: Second surface; 53: Third surface; 54: Fourth surface; 71, 72: Connection bumps; 79: Epoxy adhesive; 81, 82, 83: Bonding parts; 91: Through wiring; 92: Through wiring; 100: Ultrasonic diagnostic apparatus. Detailed implementation mode

[0021] Implementation mode 1

[0022] Outline of ultrasonic diagnostic apparatus

[0023] Figure 1 It is a perspective view of the ultrasonic diagnostic apparatus related to Implementation mode 1.

[0024] First, use Figure 1 to briefly describe the configuration of the ultrasonic diagnostic apparatus 100.

[0025] The ultrasonic diagnostic apparatus 100 of the present implementation mode is composed of a main body 10, a cable 12, a probe 13, etc.

[0026] The main body 10 is the main body of the ultrasonic diagnostic apparatus and is composed of a display unit 15, a control substrate 16, etc. In a preferred example, the display unit 15 is a liquid crystal panel with a touch panel and also functions as an operation unit. The control substrate 16 is a control unit including a control circuit that controls the transmission and reception of ultrasonic waves by the ultrasonic device 20 built in the probe 13.

[0027] The cable 12 is a wiring cable that electrically connects the main body 10 and the probe 13.

[0028] The probe 13 is a probe head and is composed of a housing part 17, an ultrasonic device 20, an acoustic lens 18, etc.

[0029] The housing portion 17 is in the shape of a rectangular box, and an acoustic lens 18 in the shape of a cylindrical surface lens is provided on its surface. The acoustic lens 18 is made of a material having an acoustic impedance close to that in the living body of the subject. In a preferred example, the acoustic lens 18 is formed of silicone resin. It should be noted that it is not limited to silicone resin, as long as it is a material having an acoustic impedance close to that of the living body. It should be noted that the direction along the long side in the rectangular housing portion 17 is set as the positive X direction, and the direction along the short side is set as the positive Y direction.

[0030] Under the acoustic lens 18 in the housing portion 17, a ultrasonic device 20 is housed. The ultrasonic device 20 is a piezoelectric ultrasonic transducer that transmits and receives ultrasonic waves. It should be noted that the details of the ultrasonic device 20 will be described later.

[0031] When performing ultrasonic diagnosis with the ultrasonic diagnostic apparatus 100, scanning is slowly performed in a state where the acoustic lens 18 side of the probe 13 is in contact with the living body of the subject. The ultrasonic waves generated in the ultrasonic device 20 are transmitted through the acoustic lens 18 and incident on the living body. The ultrasonic waves reflected by the living body are received by the ultrasonic device 20 through the acoustic lens 18.

[0032] Then, in the main body 10, an image of the received signal based on the received ultrasonic waves is generated, and the detection result is imaged and displayed on the display unit 15.

[0033] Configuration of the ultrasonic device

[0034] Figure 2 is a top view of the ultrasonic device. Figure 3 is Figure 2 a cross-sectional view taken along the b-b section of

[0035] As Figure 2 shown, the ultrasonic device 20 is rectangular when viewed from above, and the positive X direction is the long side direction, and the positive Y direction is the short side direction. As Figure 3 shown, the ultrasonic device 20 has a configuration obtained by laminating an ultrasonic substrate 22 on a second substrate 31.

[0036] Return to Figure 2 .

[0037] The ultrasonic substrate 22 is rectangular and is one size smaller than the second substrate 31, and an element array region 19 formed by arranging a plurality of ultrasonic elements 7 in a matrix is provided at its center.

[0038] In Figure 2 , the ultrasonic elements 7 are arranged in four rows in the positive Y direction and five columns in the positive X direction. It should be noted that it is not limited to this arrangement pattern, corresponding to the probe 13 ( Figure 1It can be appropriately set according to the size and specifications of ( ). In addition, the row of ultrasonic elements 7 extending in the positive Y direction is set as element row 7a. From element row 7a towards the negative Y direction, the second row is set as element row 7b, the third row is set as element row 7c, and the fourth row is set as element row 7d.

[0039] As Figure 2 shown, when viewed from above, one ultrasonic element 7 is substantially square, and this square is divided by the opening 14. It should be noted that in Figure 2 , the appearance of the element array region 19 is shown on the positive X side of the broken line, and the underlying wiring is shown in a transparent manner on the negative side of the broken line. In the opening 14, the vibrating membrane 6 is exposed, and the ultrasonic waves generated by the ultrasonic element 7 are transmitted through the vibration of the vibrating membrane 6. In addition, the vibrating membrane 6 also functions as a vibrating membrane when receiving ultrasonic waves.

[0040] On the negative Y side of the element array region 19, connection bumps 71 and connection bumps 72 are arranged in the positive X direction. The connection bumps 71 and connection bumps 72 are connection terminals for obtaining electrical connection between the ultrasonic substrate 22 and the second substrate 31. Specifically, they are connection bumps for mounting the ultrasonic substrate 22 to the second substrate 31 by the flip-chip method.

[0041] As Figure 2 shown, the connection bumps 71 and connection bumps 72 are surrounded by an adhesive portion 81. In addition, adhesive portions 82 and 83 are also provided at two vertex portions on the positive Y side of the ultrasonic substrate 22.

[0042] Figure 3 For Figure 2 the cross-sectional view at the b-b section of ( ) shows the cross-sectional structure of the ultrasonic element 7. As Figure 3 shown, the ultrasonic substrate 22 is formed by laminating the first substrate 11 and the intermediate substrate 21.

[0043] In a preferred example, the first substrate 11 uses a silicon substrate. It should be noted that it is not limited to a silicon substrate, as long as it is a hard rigid substrate.

[0044] On the negative Z side of the first substrate 11, the vibrating membrane 6 is provided. In a preferred example, the vibrating membrane 6 is configured as a two-layer structure. Specifically, the first layer on the base material side of the first substrate 11 is a silicon oxide (SiO2) layer, and the second layer is a zirconium oxide (ZrO2) layer. Preferably, the film thickness of the vibrating membrane 6 is set based on the resonance frequency of the transmitted and received ultrasonic waves. It should be noted that it is not limited to this structure, as long as it is a hard material capable of ultrasonic resonance, and it can also be composed of a single layer.

[0045] As described above, a plurality of openings 14 are provided in the first substrate 11.

[0046] The ultrasonic element 7 is disposed corresponding to the opening 14 and is composed of a diaphragm 6, a piezoelectric element 5, etc.

[0047] The piezoelectric element 5 is composed of an electrode 2, a piezoelectric body 3, an electrode 4, etc.

[0048] The electrode 2 disposed on the diaphragm 6 is a drive electrode of the piezoelectric body 3 and is composed of a conductive material. For example, metal materials such as platinum (Pt), iridium (Ir), gold (Au), aluminum (Al), copper (Cu), titanium (Ti), stainless steel, etc., tin oxide-based conductive materials such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), zinc oxide-based conductive materials, oxide conductive materials such as strontium ruthenate (SrRuO3), lanthanum nickelate (LaNiO3), element-doped strontium titanate, and conductive polymers can be used as the conductive material.

[0049] In a preferred example, the piezoelectric body 3 disposed on the electrode 2 uses a piezoelectric body layer of lead zirconate titanate (PZT). It should be noted that, without limitation, piezoelectric materials having an equivalent displacement amount can also be used.

[0050] The electrode 4 disposed on the piezoelectric body 3 is a drive electrode of the piezoelectric body 3 and is composed of the same conductive material as the electrode 2.

[0051] The intermediate substrate 21 is a cover body that covers in a manner that does not hinder the vibration of the plurality of ultrasonic elements 7. In a preferred example, a silicon substrate is used. It should be noted that, without being limited to a silicon substrate, as long as it is a hard and rigid substrate. As Figure 3 shown, a plurality of recesses for partitioning the ultrasonic elements 7 are provided in the intermediate substrate 21. The intermediate substrate 21 is bonded and fixed to the diaphragm 6 of the first substrate 11.

[0052] In the completed state of the ultrasonic substrate 22 in which the first substrate 11 and the intermediate substrate 21 are joined, a space similar to the space formed by the opening 14 on the upper side is formed on the lower side of the ultrasonic element 7. In this way, by providing spaces above and below the ultrasonic element 7, a structure that does not hinder the vibration of the ultrasonic element 7 is formed.

[0053] The electrodes 2 of the ultrasonic elements 7 adjacent to each other in the positive X direction are electrically connected through the first wiring 41. In a preferred example, the first wiring 41 is formed together in the same process when the electrode 2 is formed.

[0054] As Figure 2 shown, the electrodes 2 of the plurality of ultrasonic elements 7 constituting the element row 7a are all electrically connected through the first wiring 41. The same applies to the element rows 7b, 7c, and 7d.

[0055] In addition, the same applies in the column direction, and the electrodes 4 in the ultrasonic elements 7 adjacent in the negative Y direction are all electrically connected through the second wiring 42. It should be noted that an insulating layer is provided between the first wiring 41 and the second wiring 42 to ensure insulation.

[0056] In the present embodiment, the following driving method is adopted: a common driving signal is supplied to all the ultrasonic elements 7 in the element array region 19, and ultrasonic waves are alternately transmitted and received in accordance with a time sequence. Specifically, a common driving signal is supplied to all the ultrasonic elements 7 via the connection bumps 71. The driving signal is preferably a driving signal having a burst waveform, and since the reception time is ensured in accordance with the time sequence to be periodically transmitted, ultrasonic waves are alternately transmitted and received. In addition, a common potential such as a ground potential is supplied to all the ultrasonic elements 7 from the connection bumps 72.

[0057] Bonding structure between substrates

[0058] Figure 4 is Figure 2 a cross-sectional view taken along the c-c section.

[0059] Next, the bonding structure between the intermediate substrate 21 of the ultrasonic substrate 22 and the second substrate 31 will be described.

[0060] As Figure 4 shown, two through holes 25 and 26 are formed in the intermediate substrate 21. A first electrode 27 is provided at the bottom of the through hole 25 in the first substrate 11. Similarly, a first electrode 28 is provided at the bottom of the through hole 26. In other words, the first electrodes 27 and 28 are provided on the Z-negative side surface, i.e., the first surface 51, of the first substrate 11. The first electrode 27 is electrically connected to the second wiring 42 ( Figure 2 ) through wiring (not shown). The first electrode 28 is electrically connected to the first wiring 41 ( Figure 2 ) through wiring (not shown). That is to say, the first electrodes 27 and 28 are electrically connected to the piezoelectric element 5 ( Figure 3 ).

[0061] In addition, connection bumps 71 made of a resin-based adhesive containing metal fillers are provided in the through hole 25. Similarly, connection bumps 72 are provided in the through hole 26. The connection bumps 71 and 72 are connection bumps having anisotropic conductivity, and if they are pressed and fixed to the second substrate 31, electrical connection can be ensured in the Z-axis direction. The connection bumps 71 and 72 correspond to the third electrodes.

[0062] In a preferred example, a material containing silver filler in an epoxy resin adhesive is used as the connection bumps 71 and 72. It should be noted that this is not limited thereto, and any material with equivalent anisotropic conductivity can be used. For example, a polyurethane resin or a silicone resin-based adhesive can also be used as the resin-based adhesive. In addition, metals such as gold, copper, nickel, and tin, and metal oxides such as indium oxide can be used as the metal filler. Further, not limited to metal fillers, conductive fillers such as carbon fiber and nanotubes can also be used.

[0063] In the second substrate 31, second electrodes 37 and 38 are provided at positions corresponding to the through holes 25 and 26. In other words, the second electrodes 37 and 38 are provided on the Z-positive side surface of the second substrate 31, that is, the second surface 52.

[0064] A through wiring 91 is connected to the second electrode 37. The through wiring 91 is electrically connected to the control substrate 16 via a wiring extending from the back surface of the second substrate 31 to the outside and a cable 12( Figure 1 ). Similarly, a through wiring 92 is connected to the second electrode 38, and the through wiring 92 is also electrically connected to the control substrate 16( Figure 1 ). In other words, the second electrodes 37 and 38 are connected to the control circuit of the control substrate 16( Figure 1 ). Figure 1 ).

[0065] The second electrode 37 is a metal electrode. In a preferred example, it is composed of three layers formed by a Ni layer, a Pt layer, and an Au layer. The same applies to the second electrode 38. It should be noted that this is not limited thereto, and any metal that can electrically connect between the connection bumps 71 and 72 can be used, and it can also be a single-layer structure.

[0066] In addition, in the intermediate substrate 21, the surface facing the first surface 51 of the first substrate 11 is set as the third surface 53, and the surface facing the second surface 52 of the second substrate 31 is set as the fourth surface 54. In other words, the intermediate substrate 21 is disposed between the first substrate 11 and the second substrate 31, and includes the third surface 53 joined to the first surface 51 and the fourth surface 54 facing the second surface 52. In addition, the intermediate substrate 21 includes through holes 25 and 26 penetrating from the third surface 53 to the fourth surface 54, and connection bumps 71 and 72 provided in the through holes 25 and 26 and connected to the first electrodes 27 and 28. In addition, the second electrodes 37 and 38 are connected to the connection bumps 71 and 72, and are electrically connected to the first electrodes 27 and 28 via the connection bumps 71 and 72.

[0067] As Figure 4As shown, an adhesive portion 81 is disposed around the joint portion joining the connection bump 71 and the second electrode 37. In a preferred example, the adhesive portion 81 uses an epoxy resin adhesive as the NCP. It should be noted that it is not limited to this, and any adhesive having insulation, moisture resistance, and adhesiveness equivalent to those of the epoxy resin adhesive can be used. For example, a polyurethane resin or a silicone resin-based adhesive can also be used.

[0068] Figure 5 is Figure 2 a cross-sectional view taken along the d-d section of.

[0069] As Figure 5 shown, at the apex portion of the ultrasonic substrate 22, an adhesive portion 82 is provided between the intermediate substrate 21 and the second substrate 31. The adhesive portion 82 is the same adhesive as the adhesive portion 81. The adhesive portion 82 bonds between the second surface 52 of the second substrate 31 and the fourth surface 54 of the intermediate substrate 21. A part of the adhesive portion 82 extends from the intermediate substrate 21 and also contacts the peripheral side surface. In other words, a part of the adhesive portion 82 is also provided at the peripheral portion of the intermediate substrate 21.

[0070] In addition, between the ultrasonic substrate 22 and the second substrate 31, the portion where the adhesive portion 82 is not provided becomes a space. In other words, a gap is provided in the portion between the ultrasonic substrate 22 and the second substrate 31 where the adhesive portions 81 and 82 are not provided.

[0071] Return to Figure 2 .

[0072] When viewed from above, the connection bump 71 is rectangular, and the long side extends in the positive X direction. The connection bump 72 adjacent to the connection bump 71 is also rectangular. The second electrode 37 ( Figure 4 ) overlapping the connection bump 71 is also formed rectangular when viewed from above. The second electrode 38 ( Figure 4 ) overlapping the connection bump 72 is the same. That is, the connection bump 71 and the connection bump 72 are arranged along one long side of the ultrasonic substrate 22.

[0073] As Figure 2As shown, the bonding portion 81 is set to be rectangular when viewed from above around the connection bumps 71 and 72. That is to say, the rectangular bonding portion 81 is provided along one long side of the ultrasonic substrate 22. The length of the bonding portion 81 in the long side direction is more than half of the length of the long side of the intermediate substrate 21. The bonding portion 81 is also provided between the connection bump 71 and the connection bump 72. In addition, a part of the bonding portion 81 extends from the long side on the negative Y side of the ultrasonic substrate 22. In other words, a part of the bonding portion 81 is also provided on the peripheral portion of the intermediate substrate 21. On the other hand, the long side on the positive Y side of the bonding portion 81 does not reach the element array region 19, and the bonding portion 81 is separated from the element array region 19.

[0074] A bonding portion 82 is provided at one end on the other long side of the ultrasonic substrate 22, and a bonding portion 83 is provided at the other end. A part of the bonding portion 82 extends from one vertex of the ultrasonic substrate 22. That is to say, it also contacts the long side surface and the short side surface of the intermediate substrate 21 in the ultrasonic substrate 22. Similarly, a part of the bonding portion 83 extends from the other vertex of the ultrasonic substrate 22. That is to say, it also contacts the long side surface and the short side surface of the intermediate substrate 21 in the ultrasonic substrate 22. On the other hand, the bonding portions 82 and 83 do not reach the element array region 19, and the bonding portions 82 and 83 are provided separately from the element array region 19. In other words, the bonding portions 81, 82, and 83 are provided in a part that does not overlap with the element array region 19 when viewed from above. A plurality of the bonding portions 81, 82, and 83 are provided in an island shape separated from each other between the second substrate 31 and the intermediate substrate 21, and at least one of the bonding portions is provided to surround the connection bumps 71 and 72.

[0075] The bonding portion 81, the bonding portion 82, and the bonding portion 83 are arranged in a truss shape with the element array region 19 in between. Specifically, the bonding portion 82 and the bonding portion 83 are provided at the vertices of the base of a triangle with the center of the bonding portion 81 along one long side of the ultrasonic substrate 22 as the vertex and the other long side as the base. Thereby, the vibration in the element array region 19 is not hindered, and the bonding strength between the ultrasonic substrate 22 and the second substrate 31 is ensured. In other words, the bonding portions 81, 82, and 83 are provided at at least three places separated around the element array region 19. It should be noted that it is not limited to three places, and the joint portions can also be provided at four or more places.

[0076] Manufacturing method of ultrasonic device

[0077] Figure 6 It is a flowchart showing the manufacturing method of the ultrasonic device. Figure 7A 、 Figure 7B is Figure 2 The process diagram at the c-c cross-section of

[0078] Here, taking Figure 6 as the main body, appropriately interspersed with Figure 7A , Figure 7B , Figure 4 a manufacturing method of the ultrasonic device 20 will be described.

[0079] In step S1, a first substrate 11, an intermediate substrate 21, and a second substrate 31 are prepared. Specifically, the first substrate 11, the intermediate substrate 21, and the second substrate 31, which are manufactured through separate processes respectively, are prepared.

[0080] In step S2, the first substrate 11 and the intermediate substrate 21 are joined. Specifically, the intermediate substrate 21 is adhered to the vibration film 6 of the first substrate 11. In a preferred example, a silicon adhesive is used. In Figure 7A the ultrasonic substrate 22a in the manufacturing process of joining the first substrate 11 and the intermediate substrate 21 is shown.

[0081] In step S3, connection bumps 71 and 72 are formed. Specifically, an epoxy resin adhesive containing a silver filler is filled into two through holes 25 and 26 of the intermediate substrate 21 respectively, and heated and cured. In a preferred example, a dispenser is used to fill an appropriate amount of epoxy resin adhesive into the through holes 25 and 26. At this time, as Figure 7B shown, the connection bumps 71 and 72 protrude a certain amount from the fourth surface 54. Then, it is placed in a constant temperature bath set at a predetermined temperature for heating, and the epoxy resin adhesive is cured to form the connection bumps 71 and 72.

[0082] In step S4, NCP is coated. In a preferred example, as Figure 7B shown, an epoxy resin adhesive 79 is coated onto the second electrodes 37 and 38 of the second substrate 31. In a preferred example, a dispenser is used to coat an appropriate amount of epoxy resin adhesive 79 onto the second electrodes 37 and 38. In addition, epoxy resin adhesive is also coated onto the portions that will become the bonding portions 82 and 83 in parallel. It should be noted that it can also be coated on the ultrasonic substrate 22 side.

[0083] In step S5, the ultrasonic substrate 22 and the second substrate 31 are joined. Specifically, as Figure 7B shown, a predetermined pressure is applied in a state where the ultrasonic substrate 22 is overlapped on the second substrate 31, and in this state, it is placed in a constant temperature bath set at a predetermined temperature for heating to cure the epoxy resin adhesive. In other words, the ultrasonic substrate 22 is mounted on the second substrate 31 by the flip-chip method.

[0084] Thus, the Figure 4 ultrasonic device 20 is completed.

[0085] As described above, the ultrasonic device 20 and the ultrasonic diagnostic apparatus 100 according to the present embodiment can achieve the following effects.

[0086] The ultrasonic device 20 includes: a first substrate 11 having a first surface 51 on which a piezoelectric element 5 and first electrodes 27 and 28 connected to the piezoelectric element 5 are disposed; a second substrate 31 having a second surface 52 on which second electrodes 37 and 38 connected to a control circuit are disposed; an intermediate substrate 21 disposed between the first substrate 11 and the second substrate 31 and having a third surface 53 bonded to the first surface 51 and a fourth surface 54 facing the second surface 52; and adhesive portions 81, 82, and 83 that bond the second substrate 31 and the intermediate substrate 21. Further, the intermediate substrate 21 includes through holes 25 and 26 penetrating from the third surface 53 to the fourth surface 54, and connection bumps 71 and 72 serving as third electrodes that are provided in the through holes 25 and 26 and connected to the first electrodes 27 and 28. The second electrodes 37 and 38 are connected to the connection bumps 71 and 72 and are electrically connected to the first electrodes 27 and 28 via the connection bumps 71 and 72. The adhesive portions 81, 82, and 83 are provided in a plurality of separated island shapes between the second substrate 31 and the intermediate substrate 21, and at least one of the adhesive portions 81, 82, and 83 is provided so as to surround the connection bumps 71 and 72.

[0087] Accordingly, unlike the conventional configuration in which the entire surface between the ultrasonic device and the rigid substrate is bonded, since the second substrate 31 and the intermediate substrate 21 are bonded by the separated island-shaped adhesive portions 81, 82, and 83, the bonding area between the two is reduced, and thus the influence on the characteristics of the ultrasonic device 20 can be reduced.

[0088] In addition, since the adhesive portion 81 is provided so as to surround the connection bumps 71 and 72, moisture intrusion into the bonding portion including the connection bumps 71 and 72 can be prevented.

[0089] Therefore, it is possible to provide an ultrasonic device 20 that is mounted using a flip-chip method and can achieve desired characteristics.

[0090] In addition, the piezoelectric element 5 is disposed in contact with the diaphragm 6 and has an element array region 19 in which a plurality of piezoelectric elements 5 are regularly arranged. In a top view, the adhesive portions 81, 82, and 83 are provided in portions that do not overlap with the element array region 19.

[0091] Accordingly, since the adhesive portions are not provided in the element array region 19, oscillation of ultrasonic waves based on the ultrasonic element 7 is not hindered, and desired characteristics can be achieved.

[0092] In addition, when viewed from above, the intermediate substrate 21 is rectangular, the element array region 19 is provided at substantially the center of the intermediate substrate 21, and the bonding portions 81, 82, 83 are provided at at least three places separated around the element array region 19.

[0093] Accordingly, since the second substrate 31 and the intermediate substrate 21 are fixed by three or more bonding portions surrounding the element array region 19 when viewed from above, the rigidity of the ultrasonic device 20 as a composite structure can be ensured.

[0094] In particular, as Figure 2 shown, when fixed by the bonding portions 81, 82, 83 arranged in a truss pattern with the element array region 19 therebetween, even with three-point fixing, the rigidity required for the structure can be ensured.

[0095] In addition, the connection bumps 71, 72 serving as the third electrode are bumps made of a resin-based adhesive containing a metal filler.

[0096] Accordingly, reliable electrical connection between the first electrodes 27, 28 and the second electrodes 37, 38 can be obtained through the anisotropic conductivity of the connection bumps 71, 72.

[0097] In addition, the bonding portions 81, 82, 83 are insulating resin-based adhesives.

[0098] Accordingly, intrusion of moisture into the joint portion including the connection bumps 71, 72 can be prevented, and electrical insulation can be ensured.

[0099] In addition, a part of the bonding portions 81, 82, 83 is also provided at the peripheral portion of the intermediate substrate 21.

[0100] Accordingly, the bonding strength with the second substrate 31 can be further improved by the bonding portions extending to the peripheral portion of the intermediate substrate 21.

[0101] In addition, the ultrasonic diagnostic apparatus 100 includes the ultrasonic device 20.

[0102] Accordingly, an ultrasonic diagnostic apparatus 100 that can be mounted using the flip-chip method and can obtain desired characteristics can be provided.

[0103] Embodiment 2

[0104] Different circuit configurations of the ultrasonic device

[0105] Figure 8 is a top view of the ultrasonic device according to the present embodiment and corresponds to Figure 2 corresponding.

[0106] As Figure 8As shown, the ultrasonic device 120 of the present embodiment is in the shape of a rectangle elongated in the positive X direction, and has an element array region 119 at its center. The element array region 119 is composed of a multi-channel formed by arranging six element array regions 19 of the first embodiment in the positive X direction. The ultrasonic device 120 is formed by mounting an ultrasonic substrate 122 to a second substrate 131 by flip-chip bonding. The ultrasonic substrate 122 is in the shape of a rectangle that is one size smaller than the second substrate 131. Corresponding to the multi-channel, a plurality of connection bumps 171a for inputting drive signals are provided on the negative Y side of the element array region 119. Similarly, a plurality of connection bumps 171b are also provided on the positive Y side of the element array region 119. It should be noted that the connection bumps 171a and 171b also function as receiving terminals for the received signals of the ultrasonic waves received by the ultrasonic element 7.

[0107] In addition, connection bumps 172a and 172b for supplying a common potential are provided at approximately the middle of the two short sides of the ultrasonic substrate 122. In addition, an adhesive portion 181a surrounding a plurality of connection bumps 171a is provided along one long side of the ultrasonic substrate 122. Similarly, an adhesive portion 181b surrounding a plurality of connection bumps 171b is provided along the other long side.

[0108] In addition, an adhesive portion 182a is provided around the connection bump 172a, and an adhesive portion 182b is provided around the connection bump 172b. Except for these points, the structure is the same as that of the first embodiment. Hereinafter, the same constituent parts as those of the first embodiment are denoted by the same reference numerals, and repeated descriptions are omitted.

[0109] The adhesive portions 181a, 181b, 182a, and 182b are each independently arranged in an island shape outside the element array region 119.

[0110] The adhesive portions 181a and 181b are provided along the long side of the ultrasonic substrate 122, and a part of them extends outside the ultrasonic substrate 122. Similarly, the adhesive portions 182a and 182b are provided along the short side of the ultrasonic substrate 122, and a part of them extends outside the ultrasonic substrate 122.

[0111] In the ultrasonic device 120 having such a structure, for example, the element array regions 19 in the element array region 119 can be alternately set for transmission only and reception only. Or, the odd-numbered element rows can be set for transmission only, and the even-numbered element rows can be set for reception only. Or, various driving methods such as arranging switching elements according to the ultrasonic element 7 to actively drive the ultrasonic element 7 individually can be performed.

[0112] As described above, according to the ultrasonic device 120 of the present embodiment, in addition to the effects of the first embodiment, the following effects can also be obtained.

[0113] In the ultrasonic device 120, a plurality of bonding portions 181a, 181b, 182a, and 182b are provided in an island shape separated from each other between the second substrate 131 and the ultrasonic substrate 122, and each bonding portion is provided so as to surround a corresponding connection bump.

[0114] Accordingly, since the bonding area between the second substrate 131 and the ultrasonic substrate 122 is reduced by bonding them with the separated island-shaped bonding portions 181a, 181b, 182a, and 182b, the influence on the characteristics of the ultrasonic device 20 can be reduced. In addition, since the bonding portions are provided so as to surround the corresponding connection bumps, moisture intrusion into the bonding portion including the connection bumps can be prevented.

[0115] Therefore, it is possible to provide the ultrasonic device 120 that is mounted using the flip-chip method and can obtain desired characteristics.

Claims

1. An ultrasonic device, characterized in that, Comprising: A first substrate including a first surface on which a piezoelectric element and a first electrode connected to the piezoelectric element are disposed; A second substrate including a second surface on which a second electrode connected to a control circuit is disposed; An intermediate substrate disposed between the first substrate and the second substrate and including a third surface joined to the first surface and a fourth surface opposite to the second surface; and An adhesive portion bonding the second substrate and the intermediate substrate, The intermediate substrate has a through-hole penetrating from the third surface to the fourth surface and a third electrode disposed in the through-hole and connected to the first electrode, The second electrode is connected to the third electrode and electrically connected to the first electrode via the third electrode, The adhesive portion has insulation, moisture resistance, and adhesiveness, and in the space between the second substrate and the intermediate substrate, the adhesive portion contacts the peripheral side surface of the intermediate substrate and is provided in a plurality of separated island shapes, At least one of the adhesive portions is provided so as to surround the joint portion of the second electrode and the third electrode, the second electrode, and the third electrode.

2. The ultrasonic device according to claim 1, wherein The piezoelectric element is disposed in contact with the vibration film, The ultrasonic device has an element array region formed by regularly arranging a plurality of the piezoelectric elements, When viewed from above, the adhesive portion is disposed in a portion that does not overlap with the element array region.

3. The ultrasonic device according to claim 2, wherein When viewed from above, the intermediate substrate is rectangular, The element array region is disposed at the center of the intermediate substrate, The adhesive portion is disposed at at least three separated places around the element array region.

4. The ultrasonic device according to any one of claims 1 to 3, wherein The third electrode is a bump made of a resin-based adhesive containing a metal filler.

5. The ultrasonic device according to claim 1, wherein The adhesive portion is an insulating resin-based adhesive.

6. An ultrasonic diagnostic apparatus, characterized in that, Comprising: The ultrasonic device according to any one of claims 1 to 5.

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