Ultrasonic probe

Abstract

To enable ground wiring to be performed easily and reliably in an ultrasonic probe.SOLUTION: A vibrator array 16 includes two dummy vibrators 22 adjacent to an effective part 16A. Each dummy vibrator 22 includes a conductive part consisting of a dummy piezoelectric layer and a dummy reflection layer. A ground line in a wiring sheet 26 is electrically connected to a ground film through the two conductive parts. Two second slits 24 are provided between the two dummy vibrators 22 and the effective part 16A. The wiring sheet 26 includes a lower side wiring pattern, an upper side wiring pattern, and a via group.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an ultrasonic probe, and particularly to the structure of an ultrasonic probe.

Background Art

[0002] In ultrasonic inspection, an ultrasonic probe is used. Known ultrasonic probes include those that are brought into contact with the body surface of a subject, those that are inserted into a subject, and those that are incorporated into an endoscope. The ultrasonic probe incorporated into an endoscope can also be referred to as an ultrasonic sensor.

[0003] An ultrasonic probe has an assembly disposed within a case. The assembly has, for example, a backing, a wiring sheet, a transducer array, a ground film, an acoustic lens, etc. The transducer array is composed of a plurality of transducers arranged in the longitudinal direction. The longitudinal direction is the direction of transducer arrangement, which is also called the major axis direction. The direction perpendicular to the longitudinal direction is called the minor axis direction or the short axis direction. The wiring sheet is generally composed of a flexible printed circuit (FPC) board. The ground film is composed of copper foil or the like.

[0004] Each of the plurality of transducers constituting the transducer array has a piezoelectric layer. Each piezoelectric layer is composed of a piezoelectric material, which is a mechanoelectric conversion material, and has a signal electrode and a ground electrode. The plurality of signal electrodes of the plurality of piezoelectric layers are connected to a plurality of signal lines within the wiring sheet. The plurality of ground electrodes of the plurality of piezoelectric layers are connected to one or a plurality of ground lines within the wiring sheet via the ground film.

[0005] FIG. 2 of Patent Document 1 discloses an ultrasonic probe having a transducer array and a wiring sheet. The wiring sheet has a first portion provided below the transducer array and a pair of second portions drawn out from both longitudinal sides of the first portion. FIG. 9 of Patent Document 1 shows a structure for connecting signal lines and ground lines to a piezoelectric layer.

[0006] Vibrator arrays and wiring sheets are also disclosed in FIGS. 3 and 7 of Patent Document 2. Patent Documents 1 and 2 do not disclose dummy vibrators for ground wiring.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] In an assembly disposed within an ultrasonic probe, when both ends of a ground film are connected to a ground line of a wiring sheet by soldering, the work burden increases, an area for soldering has to be secured on the wiring sheet, and thermal damage is caused to the piezoelectric layer array, and other problems occur.

[0009] An object of the present disclosure is to enable easy and reliable ground wiring in an ultrasonic probe. Alternatively, an object of the present disclosure is to provide a vibrator array having good electrical characteristics and good physical characteristics.

Means for Solving the Problems

[0010] The ultrasonic probe according to the present disclosure includes an oscillator array having a plurality of real oscillators each having a plurality of real piezoelectric layers and a dummy oscillator having a dummy piezoelectric layer, a ground film provided above the plurality of real piezoelectric layers and the dummy piezoelectric layer and electrically connected to a plurality of ground electrodes of the plurality of real piezoelectric layers and an upper surface electrode of the dummy piezoelectric layer, and a wiring sheet provided below the oscillator array and having a plurality of signal lines electrically connected to a plurality of signal electrodes of the plurality of real piezoelectric layers and a ground line electrically connected to the ground film. The dummy oscillator has a conductive portion provided between the ground film and the wiring sheet and including the dummy piezoelectric layer, and the ground film and the ground line are electrically connected through the conductive portion.

Advantages of the Invention

[0011] According to the present disclosure, in an ultrasonic probe, ground wiring can be performed easily and reliably. Alternatively, according to the present disclosure, an oscillator array having good electrical characteristics and good physical characteristics can be provided.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0013] Hereinafter, embodiments will be described with reference to the drawings.

[0014] (1) Outline of the Embodiment The ultrasonic probe according to the embodiment has a transducer array, a ground film, and a wiring sheet. The transducer array has a plurality of real transducers having a plurality of real piezoelectric layers and a dummy transducer having a dummy piezoelectric layer. The ground film is provided above the plurality of real piezoelectric layers and the dummy piezoelectric layer. More specifically, the ground film is electrically connected to the plurality of ground electrodes of the plurality of real piezoelectric layers and the upper surface electrode of the dummy piezoelectric layer. The wiring sheet is provided below the transducer array. More specifically, the wiring sheet has a plurality of signal lines electrically connected to the plurality of signal electrodes of the plurality of real piezoelectric layers and a ground line electrically connected to the ground film. The dummy transducer has a conductive portion provided between the ground film and the wiring sheet. The conductive portion has a dummy piezoelectric layer. The ground film and the ground line are electrically connected via the conductive portion.

[0015] According to the above configuration, since the ground film and the ground line are electrically connected via the conductive portion in the dummy transducer, it is not necessary to solder the ground film to the wiring sheet. Therefore, ground wiring can be performed easily and reliably. In addition, the acoustic characteristics of the transducer array can be maintained or improved. In the present specification, the expression "electrical connection" may include direct connection and indirect connection.

[0016] In an embodiment, the dummy piezoelectric layer has an upper surface electrode, a lower surface electrode, and side surface electrodes connected to the upper surface electrode and the lower surface electrode. The side surface electrodes function as short-circuit electrodes. Two dummy oscillators may be provided on both sides of an effective portion including a plurality of real oscillators. Three or more dummy oscillators may be provided. The side surface electrodes are electrodes formed on a vertical plane (a plane intersecting the oscillator array direction) in the piezoelectric layer.

[0017] In an embodiment, the plurality of real oscillators have a plurality of real reflective layers having conductivity provided on the lower sides of the plurality of real piezoelectric layers. The conductive portion has a dummy reflective layer having conductivity provided on the lower side of the dummy oscillator. Each real reflective layer has a function of reflecting ultrasonic waves emitted from each piezoelectric layer downward. In the dummy oscillator, both the dummy piezoelectric layer and the dummy reflective layer function as electrical connection components.

[0018] In an embodiment, the oscillator array has a longitudinal direction. The width of the dummy oscillator in the longitudinal direction is larger than the width of each real oscillator in the longitudinal direction. According to this configuration, the electrical resistance of the ground path can be reduced. Also, the oscillator array can be physically strengthened. Generally, at both ends in the longitudinal direction of the oscillator array, oscillator breakage (specifically, oscillator collapse) is likely to occur. According to the above configuration, such problems are less likely to occur.

[0019] In an embodiment, the oscillator array has an effective portion and a second slit. The effective portion is composed of a plurality of real oscillators and a plurality of first slits for separating each real oscillator from other real oscillators. The second slit is provided between the effective portion and the dummy oscillator. The width of the second slit in the longitudinal direction is larger than the width of each first slit in the longitudinal direction.

[0020] According to the above configuration, insulation can be enhanced between the actual oscillator existing at the end of the effective portion and the adjacent dummy oscillator. For example, when the effective portion is subjected to a re-poling process, a short circuit between the actual oscillator existing at the end and the adjacent dummy oscillator is less likely to occur. When the oscillator array has a curved form, the longitudinal width of the second slit is the width of the bottom in the second slit. Similarly, the longitudinal width of each first slit is the width of the bottom in each first slit.

[0021] In an embodiment, the ground film includes a film body having a plurality of strips and a pair of film ends connected to the plurality of strips. The plurality of strips includes a plurality of strips electrically joined to a plurality of ground electrodes and a strip electrically joined to the upper surface electrode of the dummy piezoelectric layer. Each individual strip is an elongated piece or a strip-shaped portion.

[0022] In an embodiment, the oscillator array has a longitudinal direction and a short direction intersecting the longitudinal direction. The wiring sheet has an upper wiring pattern, a lower wiring pattern, and a via group. The upper wiring pattern has a plurality of upper signal lines arranged in the longitudinal direction and electrically connected to the signal electrodes of the plurality of actual oscillators, and an upper ground line electrically connected to the lower surface electrode of the dummy oscillator. The lower wiring pattern has a plurality of lower signal lines arranged in the short direction and a lower ground line. The via group has a plurality of signal vias connecting the plurality of upper signal lines and the plurality of lower signal lines, and a ground via electrically connecting the upper ground line and the lower ground line.

[0023] In an embodiment, the wiring sheet has a sheet body, a first extension portion, and a second extension portion. The sheet body is provided below the vibrator array. The sheet body has one end and the other end separated in the longitudinal direction. The first extension portion is a portion drawn out from one end of the sheet body. The second extension portion is a portion drawn out from the other side of the sheet body. The plurality of actual vibrators are n actual vibrators from the first actual vibrator to the nth actual vibrator arranged in numerical order in the longitudinal direction. The plurality of lower signal lines have a first lower signal line group and a second lower signal line group. The first lower signal line group is electrically connected to the odd-numbered actual vibrators among the n actual vibrators and is provided across the sheet body and the first extension portion. The second lower signal line group is electrically connected to the even-numbered actual vibrators among the n actual vibrators and is provided across the sheet body and the second extension portion.

[0024] In an embodiment, the plurality of signal vias have a first signal via row connected to the first lower signal line group and a second signal via row connected to the second lower signal line group. The first signal via row is aligned along the diagonal direction of the sheet body. The second signal via row is aligned along the diagonal direction while shifting from the first signal via row.

[0025] According to the above configuration, it is possible to reduce the inclination angle of each signal via row with respect to the longitudinal direction while ensuring a certain signal via pitch. Therefore, the width of the wiring sheet in the short side direction can be reduced.

[0026] The ultrasonic probe according to the embodiment includes a first assembly (intermediate assembly), a backing, and a case. The first assembly is composed of a transducer array, a ground film, and a wiring sheet. The backing is provided below the first assembly. The backing has a first end portion and a second end portion spaced apart in the longitudinal direction. The case houses a second assembly composed of the first assembly and the backing. The wiring sheet has a sheet body, a first extension portion, and a second extension portion. The sheet body is a portion provided below the transducer array. The sheet body has one end and the other end spaced apart in the longitudinal direction. The first extension portion is a portion drawn out from one end of the sheet body. The second extension portion is a portion drawn out from the other side of the sheet body. The first extension portion enters the lower space through the space adjacent to the first end portion, and then turns in a U shape within the lower space. The second extension portion enters the lower space through the space adjacent to the second end portion. The end portion of the first extension portion and the end portion of the second extension portion overlap below the backing.

[0027] According to the above configuration, since the two end portions in the two extension portions overlap, even if the lower space is a small space, a large number of cables (for example, 100 or more cables) can be connected to the wiring sheet using the lower space.

[0028] (2) Details of the Embodiment FIG. 1 shows the tip portion 10 of the endoscope. The endoscope has an imaging element, an illumination element, a water / air supply hole, a channel opening, etc., but their illustrations are omitted. Inside the tip portion 10, the ultrasonic probe 12 according to the embodiment is incorporated. The ultrasonic probe 12 according to the embodiment may be incorporated into other endoscopes. The ultrasonic probe 12 may be used alone. The ground wiring technology and the like described below may be applied to other ultrasonic probes (for example, ultrasonic probes that contact the body surface).

[0029] In FIG. 1, the a direction is the central axis direction of the ultrasonic probe. The b direction is the longitudinal direction, which is the direction of the transducer array. The b direction intersects the a direction. The direction intersecting the a direction and the b direction is the short-side direction. The a direction is inclined with respect to the endoscope central axis (the central axis of the distal end portion 10). As viewed from the ultrasonic probe 12, the a direction can be said to be the vertical direction. In that case, the upward direction is the ultrasonic radiation direction.

[0030] The ultrasonic probe 12 is a convex ultrasonic probe. The ultrasonic probe 12 has an assembly (second assembly, final assembly) 15, and the assembly 15 is composed of an intermediate assembly (first assembly), a backing 14, and an acoustic lens 19. The intermediate assembly is composed of a transducer array 16, a ground film 18, and a wiring sheet 26.

[0031] The transducer array 16 is composed of a plurality of transducers arranged in the longitudinal direction. In FIG. 1, the illustration of the middle part of the transducer array 16 is omitted. Specifically described, the transducer array 16 has an effective part 16A for transmitting and receiving ultrasonic waves. The effective part 16A has a plurality of active transducers 20 arranged in the longitudinal direction. The effective part 16A also has a plurality of first slits for separating individual active transducers 20 from other transducers. Along the longitudinal direction, the plurality of active transducers 20 and the plurality of first slits are alternately provided.

[0032] The transducer array 16 has two dummy transducers 22 provided on both longitudinal sides of the effective part 16A. Each dummy transducer 22 does not exhibit an acoustic function but exhibits an electrical function. As will be described in detail later, each dummy transducer 22 is a conductive member for ground wiring. The transducer array 16 has two second slits (gaps) 24 provided between the two dummy transducers 22 and the effective part 16A.

[0033] The plurality of vibrators in the vibrator array 16 have a plurality of piezoelectric layers. A ground film 18 is provided above the plurality of piezoelectric layers (however, the ground film 18 is not explicitly shown in FIG. 1). The ground film 18 is composed of, for example, a copper foil. In an embodiment, the upper surface electrodes (ground electrodes) of the plurality of piezoelectric layers in the plurality of vibrators are joined to the ground film 18.

[0034] An acoustic lens 19 is provided above the vibrator array 16. The acoustic lens 19 has a function of focusing ultrasonic waves in the short side direction. A ground film 18 may be provided between the vibrator array 16 and the acoustic lens 19. In that case, a conductive matching layer is provided as a matching layer in each vibrator.

[0035] A wiring sheet 26 is provided below the vibrator array 16. The wiring sheet 26 is composed of a flexible printed circuit (FPC) board. In an embodiment, the wiring sheet 26 is composed of a multilayer FPC board. The wiring sheet 26 has a sheet body 28 provided below the vibrator array 16, an extension portion 30 drawn out from one end in the longitudinal direction of the sheet body 28, and an extension portion 32 drawn out from the other end in the longitudinal direction of the sheet body 28.

[0036] The sheet body 28 is joined to the upper surface of the backing 14. The upper surface is a curved convex surface. The backing 14 is a member that attenuates ultrasonic waves radiated downward from the vibrator array 16. The backing 14 has a first end portion 14A and a second end portion 14B separated in the longitudinal direction. The first end portion 14A has a first side surface intersecting the longitudinal direction. The second end portion 14B has a second side surface intersecting the longitudinal direction. The backing 14 further has a third side surface and a fourth side surface intersecting the short side direction, and also has a lower surface. The lower surface faces the lower space 33.

[0037] The extension portion 30 enters the lower space 33 after passing through the space adjacent to the first end portion 14A, and then turns in a U shape within the lower space 33. The extension portion 30 has a first portion 30a, a second portion 30b, and a third portion 30c. The first portion 30a is the portion in contact with the first side surface of the first end portion 14A. The second portion 30b is the portion in contact with the lower surface of the backing 14. The third portion 30c is the portion running parallel to the second portion 30b below the second portion 30b. The space between the seat body 28 and the first portion 30a is a bent portion, the space between the first portion 30a and the second portion 30b is a bent portion, and the space between the second portion 30b and the third portion 30c is a turning portion.

[0038] The extension portion 32 enters the lower space 33 through the space adjacent to the second end portion 14B. The extension portion 32 has a first portion 32a and a second portion 32b. The first portion 32a is the portion in contact with the second side surface of the second end portion 14B. The second portion 32b is the portion that enters below the third portion 30c. The space between the seat body 28 and the first portion 32a is a bent portion, and the space between the first portion 32a and the second portion 32b is a curved portion.

[0039] A first connection region is provided on the upward-facing surface of the end of the third portion 30c. A plurality of cables constituting the cable group 34 are connected to the first connection region. A second connection region is provided on the downward-facing surface of the end of the second portion 32b. A plurality of cables constituting the cable group 36 are connected to the second connection region. Each of the cable groups 34, 36 is composed of several tens or several hundreds of cables. In FIG. 1, the cable groups 34, 36 are schematically represented. Within the lower space 33, the end of the third portion 30c and the end of the second portion 32b overlap. The lengths of the extension portion 30 and the extension portion 32 are determined so that such an overlap occurs.

[0040] The intermediate assembly is constituted by the wiring sheet 26, the vibrator array 16, and the ground film 18. The assembly (second assembly, final assembly) 15 is constituted by the intermediate assembly, the backing 14, and the acoustic lens 19. The assembly 15 is disposed in the case of the tip portion 10. When the assembly 15 is disposed in the case, a lower space 33 is formed below the backing 14. Two ends of the wiring sheet 26 are accommodated in the lower space 33.

[0041] FIG. 2 schematically shows a vertical cross section of the intermediate assembly 44. The intermediate assembly 44 is constituted by the wiring sheet 26, the vibrator array 16, and the ground film 18. In FIG. 2, the intermediate assembly 44 is in a developed state, that is, in a state before bending. Note that the horizontal y direction corresponds to the longitudinal direction, and the vertical z direction corresponds to the central axis direction.

[0042] The vibrator array 16 has an effective portion 16A, two dummy vibrators 22, and two second slits 24. The effective portion 16A has a plurality of real vibrators 20 and a plurality of first slits 42. Each real vibrator 20 has a piezoelectric layer (real piezoelectric layer) 46, a reflective layer (real reflective layer) 48, and a matching layer (real matching layer) 52. The matching layer 52 may be constituted by a plurality of layers.

[0043] Each piezoelectric layer 46 has a signal electrode as a lower surface electrode and a ground electrode as an upper surface electrode. A strip 50 in the ground film is joined to the ground electrode. In other words, the strip 50 is sandwiched between the ground electrode and the matching layer 52.

[0044] The reflective layer 48 has a function of reflecting ultrasonic waves radiated downward from the piezoelectric layer 46. The acoustic impedance of the reflective layer 48 is larger than the acoustic impedance of the piezoelectric layer 46. The piezoelectric layer 46 and the reflective layer 48 are integrated, thereby constituting a resonator.

[0045] Each dummy oscillator 22 has a dummy piezoelectric layer 54, a dummy reflective layer 56, and a dummy matching layer 60. The dummy piezoelectric layer 54 has conductivity or a short-circuit function. Specifically, the dummy piezoelectric layer 54 has a bottom electrode 62, a top electrode 64, and a side electrode 66. The bottom electrode 62 and the top electrode 64 are electrically connected by the side electrode 66, that is, the space between the bottom electrode 62 and the top electrode 64 is short-circuited. A strip 58 is bonded to the top electrode 64.

[0046] The plurality of piezoelectric layers 46 and the two dummy piezoelectric layers 54 are each composed of the same piezoelectric material (for example, PZT). The plurality of reflective layers 48 and the two dummy reflective layers 56 are each composed of the same conductive material. The plurality of matching layers 52 and the two dummy matching layers 60 are each composed of the same material. Each dummy oscillator 22 does not function acoustically but functions electrically. That is, it functions as an electrical component for ground wiring.

[0047] The wiring sheet 26 has an insulating layer 68, a lower wiring pattern (lower wiring layer) 70, and an upper wiring pattern (upper wiring layer) 72. The sheet body 28 in the wiring sheet 26 has a via group 74. The via group 74 includes a plurality of signal vias 76 and a plurality of ground vias 78. Each via is an element that electrically connects the lower electrode pattern and the upper electrode pattern, specifically, a conductive through-hole.

[0048] The lower wiring pattern 70 includes a plurality of lines arranged in the short direction, specifically, a plurality of lower signal lines and a plurality of lower ground lines. The upper wiring pattern 72 includes a plurality of lines arranged in the long direction, specifically, a plurality of upper signal lines and a plurality of upper ground lines. Each line corresponds to an electrode or an electrical path.

[0049] The plurality of lower signal lines are connected to the plurality of upper signal lines 94 through the plurality of signal vias 76. The plurality of upper signal lines 94 are connected to the plurality of signal electrodes of the plurality of piezoelectric layers 46 through the plurality of reflective layers 48.

[0050] In each dummy oscillator 22, the dummy piezoelectric layer 54 has conductivity, and the dummy reflection layer 56 below it also has conductivity. Therefore, in each dummy oscillator 22, the dummy piezoelectric layer 54 and the dummy reflection layer 56 constitute a conductive portion. For example, the lower ground line is connected to the upper ground line 96 via the ground via 78. The upper ground line 96 is connected to the ground film 18 via the conductive portion.

[0051] The lower ground line and the upper ground line may be connected by a plurality of ground vias. Also, a structure for connecting the ground line and the ground film may be provided in the effective portion 16A.

[0052] For example, in each piezoelectric layer 46, the length in the short direction is, for example, 2 mm or 3 mm, the width 82 in the y direction is, for example, 100 μm, and the thickness in the z direction is, for example, 100 μm. In each dummy piezoelectric layer 54, the length in the short direction is, for example, 2 mm or 3 mm, the width 84 in the y direction is, for example, 150 μm, and the thickness in the z direction is, for example, 100 μm. The numerical values given in this specification are all merely examples.

[0053] In the embodiment, the width 84 is larger than the width 82. As a result, the electrical resistance of the ground path is reduced. Also, the structures at both ends of the oscillator array 16 are physically strengthened. It is difficult for each dummy oscillator 22 to fall over. Since two dummy oscillators 22 are provided on both longitudinal sides of the effective portion 16A, the effective portion 16A is physically protected.

[0054] The width 86 of each first slit 42 in the y direction is, for example, 50 μm. The width 88 of each second slit 88 in the y direction is, for example, 100 μm. The width 88 is larger than the width 86. Thereby, it is possible to effectively prevent an electrical short circuit between the actual oscillators at both ends in the effective portion 16A and the two dummy oscillators 22 adjacent thereto. For example, in the re-poling process of the effective portion 16A, a high voltage is applied to the effective portion 16A. At that time, a short circuit or a polarization defect can be prevented.

[0055] In each piezoelectric layer 46, the lower surface electrode (signal electrode) and the upper surface electrode (ground electrode) are formed by gold plating or the like. Their thickness is, for example, 0.3 μm. In each dummy piezoelectric layer 54, the lower surface electrode 62, the upper surface electrode 64, and the side surface electrode 66 are formed by gold plating or the like. Their thickness is, for example, 0.3 μm. The ground film 18 includes, for example, a copper foil with a thickness of 5 μm. The surface of the ground film 18 is also plated with gold. The thickness of the gold plating layer is, for example, 0.3 μm.

[0056] In the manufacturing process of the ultrasonic probe, as will be described later, a reflector plate, a piezoelectric material plate, and a matching material plate are stacked on the sheet body 28 in the wiring sheet 26. They are adhered to each other. Thereby, a laminate is formed. Then, dicing 90, 92 of the laminate by a dicing saw is performed. Thereby, the intermediate assembly 44 is formed. The intermediate assembly 44 is adhered to the upper surface of the backing. Also, an acoustic lens is adhered to the upper side of the intermediate assembly 44. Through the above process, the final assembly is manufactured. The final assembly corresponds to an ultrasonic sensor. The final assembly is disposed in a case.

[0057] FIG. 3 shows the wiring sheet 26 in an unfolded state. The wiring sheet 26 is composed of a sheet body 28, an extension portion 30, and an extension portion 23. The y direction is the longitudinal direction, and the x direction is the short side direction. An oscillator array 16 is provided on the sheet body 28. The wiring sheet 26 has a lower wiring pattern. The lower wiring pattern includes a first lower wiring pattern 100 and a second lower wiring pattern 102.

[0058] The first lower wiring pattern 100 is formed across the sheet body 28 and the extension portion 30. In FIG. 3, part of the first lower wiring pattern 100 is not shown. The second lower wiring pattern 102 is formed across the sheet body 28 and the extension portion 32. In FIG. 3, part of the second lower wiring pattern 102 is not shown. A connection region 104 is provided at the end of the extension portion 30. A connection region 106 is provided at the end of the extension portion 32.

[0059] FIG. 4 shows a part of the sheet body 28. The upper wiring pattern 72 is composed of a plurality of lines arranged in the longitudinal direction. Specifically, the upper wiring pattern 72 is composed of a plurality of upper signal lines 94 and two upper ground lines 96. However, in FIG. 4, only one of the two upper ground lines 96 is shown.

[0060] As described above, the lower wiring pattern 70 is composed of the first lower wiring pattern 100 and the second lower wiring pattern 102. Specifically, the first lower wiring pattern 100 is composed of a first group of lower signal lines and a first lower ground line, and the second lower wiring pattern 102 is composed of a second group of lower signal lines and a second lower ground line. Hereinafter, the wiring patterns in the wiring sheet will be described in more detail.

[0061] The plurality of real oscillators are composed of n real oscillators from the first real oscillator to the nth real oscillator arranged in numerical order in the longitudinal direction (n is an integer of 2 or more, for example, 60 or more and 300 or less). The n real oscillators are connected to the n upper signal lines 94. The two dummy oscillators are connected to the two upper ground lines 96.

[0062] The first lower wiring pattern 100 includes a plurality of first lower signal lines 112 connected to odd-numbered actual oscillators, and also includes a first lower ground line connected to one dummy oscillator. A plurality of first lower signal lines 112 connected to odd-numbered actual oscillators constitute a first lower signal line group.

[0063] The second lower wiring pattern 102 includes a plurality of second lower signal lines 113 connected to even-numbered actual oscillators, and also includes a second lower ground line 114 connected to the other dummy oscillator. A plurality of second lower signal lines 113 connected to even-numbered actual oscillators constitute a second lower signal line group.

[0064] The via group 74 includes a first via row 115 and a second via row 116, and also includes a plurality of ground vias 78. The first via row 115 is composed of a plurality of signal vias 76A connected to odd-numbered actual oscillators, and the second via row 116 is composed of a plurality of signal vias 76B connected to even-numbered actual oscillators. The first via row 115 is formed along the diagonal direction of the sheet body 28, and the second via row 116 is also formed along the diagonal direction of the sheet body 28. However, the first via row 115 and the second via row 116 are shifted in the y direction relative to each other.

[0065] FIG. 5 shows a piezoelectric layer array 118 and a wiring sheet 26. The piezoelectric layer array 118 is fabricated by dicing 122 and is composed of a plurality of piezoelectric layers arranged in the longitudinal direction. Specifically, the piezoelectric layer array 118 includes a plurality of piezoelectric layers (actual piezoelectric layers) 46 and two dummy piezoelectric layers 54. A ground film 18 is provided above the piezoelectric layer array 118. However, in FIG. 5, the ground film 18 is schematically represented.

[0066] The wiring sheet 26 includes a lower wiring pattern 70 and an upper wiring pattern 72. In FIG. 5, a ground line (second lower ground line) 114 in the lower wiring pattern 70 is shown. The ground line 114 is connected to the upper ground line 96 via a ground via 78. The upper ground line 96 is connected to the ground film 18 via a dummy reflective layer (not shown) and the dummy piezoelectric layer 54.

[0067] FIG. 6 shows the ground film 18 in the unfolded state. The ground film 18 is easily deformable. The ground film 18 is composed of a film body 140 and a pair of film end portions 142A and 142B connected to both sides in the short side direction of the film body 140. The reference numerals 124 and 126 indicate folding lines, respectively.

[0068] The film body 140 has a strip row 128 composed of a plurality of strips arranged in the longitudinal direction. The strip row 128 includes a plurality of strips 130 joined to the upper electrodes of a plurality of piezoelectric layers (actual piezoelectric layers) 46 and two strips 132 joined to the upper electrodes of two dummy piezoelectric layers 54.

[0069] The film body 140 has a plurality of openings 134 corresponding to a plurality of first slits and two openings 136 corresponding to two second slits. The plurality of openings 134 and 136 are formed by dicing the laminate. The reference numeral 138 indicates the dicing depth. During the production of the assembly, the two film end portions 142A and 142B may be attached to the two side surfaces of the backing.

[0070] FIGS. 7 to 9 show some wiring patterns. In each figure, #1 indicates the first upper signal line connected to the first vibrator (actual vibrator), and #2 indicates the second upper signal line connected to the second vibrator (actual vibrator). The same applies to #3, #4, ···.

[0071] FIG. 7 shows a first example of a wiring pattern. The upper wiring pattern 144 includes a plurality of upper signal lines 145 arranged in the longitudinal direction (y direction). The lower wiring pattern 146 is divided into a first portion 148 and a second portion 150 arranged in the short-side direction (x direction). The first portion 148 includes a plurality of lower signal lines 147 drawn to the right side in FIG. 7. The second portion 150 includes a plurality of lower signal lines drawn to the left side in FIG. 7. The via group 152 is composed of a plurality of vias 154 arranged in the diagonal direction of the sheet body.

[0072] In FIG. 7, reference numeral 158 indicates the via pitch. θ1 indicates the inclination angle of the via group 152.

[0073] FIG. 8 shows a second example of a wiring pattern. The upper wiring pattern 160 includes a plurality of upper signal lines 161 arranged in the longitudinal direction (y direction). The lower wiring pattern 162 includes a plurality of lower signal lines arranged in the short-side direction. More specifically, the plurality of lower signal lines consists of odd-numbered lower signal lines 163 and even-numbered lower signal lines 164. They are alternately arranged in the short-side direction. The via group 168 is composed of a plurality of vias arranged in the diagonal direction of the sheet body.

[0074] In FIG. 8, reference numeral 172 indicates the via pitch. θ2 indicates the inclination angle of the via group 152. According to the second example shown in FIG. 8, it is possible to increase the via pitch 172, that is, to decrease the inclination angle θ2, compared with the above first example. Therefore, according to the second example, the width of the wiring sheet in the x direction can be decreased.

[0075] FIG. 9 shows a third example of a wiring pattern. The upper wiring pattern 180 includes a plurality of upper signal lines 190 and two upper ground lines 192 arranged in the longitudinal direction. However, in FIG. 9, only one of the two upper ground lines 192 is shown.

[0076] The lower wiring pattern 182 includes a first lower wiring pattern 186 and a second lower wiring pattern 188. The first lower wiring pattern 186 includes a plurality of lower signal lines 187 and a lower ground line. The second lower wiring pattern 188 includes a plurality of lower signal lines 189 and a lower ground line 200.

[0077] More specifically, the lower wiring pattern 182 includes n lower signal lines from the first lower signal line to the nth lower signal line. The n lower signal lines are connected to n oscillators (actual oscillators). The odd-numbered lower signal lines 187 are connected to the odd-numbered oscillators (actual oscillators). The even-numbered lower signal lines 189 are connected to the even-numbered oscillators (actual oscillators). The odd-numbered lower signal lines 187 and the even-numbered lower signal lines are alternately arranged in the short direction.

[0078] The via group 184 is composed of a first via row 194 and a second via row 196. The first via row is composed of odd-numbered first signal vias A1, A3, A5, A7, A9,... connected to the odd-numbered lower signal lines 187. The second via row 196 is composed of even-numbered second signal vias A2, A4, A6, A8,... connected to the even-numbered lower signal lines 189.

[0079] The first via row 194 and the second via row 196 are formed along the diagonal direction of the sheet body. The first via row 194 and the second via row 196 are shifted in the y direction (refer to the reference numeral 196). It can also be said that they are shifted in the x direction. From the first signal via to the nth signal via, n signal vias are arranged in a zigzag pattern. Note that A0 indicates a ground via. One or more lower ground lines may be connected to one upper ground line 192 via a plurality of ground vias.

[0080] When the third example is adopted, compared with the second example above, it becomes possible to further increase the via pitch, that is, the inclination angles of the first via row 194 and the second via row 196 can be made smaller. Therefore, according to the third example, the width of the wiring sheet in the x direction can be further reduced. Also, according to the third example, it is easy to reduce the pitch between the vibrators.

[0081] FIG. 10 shows a method for manufacturing an ultrasonic probe according to an embodiment. In S10, a reflector plate, a piezoelectric material plate, a ground film, and one or more matching material plates are laminated on the sheet body of the wiring sheet, and they are adhered to each other. Thereby, a laminate is produced on the wiring sheet.

[0082] In S12, dicing of the laminate is performed. Thereby, a vibrator array is produced from the laminate. An intermediate assembly is constituted by the wiring sheet and the vibrator array. In S14, the intermediate assembly is adhered to the upper surface of the backing. Further, an acoustic lens is adhered on the upper side of the vibrator array. Thereby, an assembly is produced. A cable group is connected to two extending portions in the assembly. In S16, the assembly is disposed in a case. Thereby, the ultrasonic probe shown in FIG. 1 is constituted.

[0083] According to the above embodiment, the ground wiring can be easily and surely performed by the dummy vibrators. Therefore, a vibrator array having good acoustic characteristics can be realized. In the above embodiment, in the vibrator array, two dummy vibrators are provided on both longitudinal sides of the effective portion, so that the physical strength of the vibrator array can be enhanced. In particular, the advantage that the vibrator is less likely to fall at both ends of the vibrator array can be obtained. Further, in the above embodiment, in the wiring sheet, the odd-numbered lower signal lines and the even-numbered lower signal lines are arranged alternately, so that the electrical crosstalk in the wiring sheet can be reduced. The characteristic matters regarding the wiring pattern in the wiring sheet can also be adopted in an ultrasonic probe having no dummy vibrator.

Explanation of Signs

[0084] 10 Tip, 12 ultrasonic probe, 14 backing, 15 assembly, 16 transducer array, 16A effective part, 18 ground film, 19 acoustic lens, 20 actual transducer, 22 dummy transducer, 24 second slit, 26 wiring sheet, 42 first slit, 46 piezoelectric layer (actual piezoelectric layer), 48 reflective layer (actual reflective layer), 52 matching layer (actual matching layer), 54 dummy piezoelectric layer, 56 dummy reflective layer, 60 dummy matching layer, 70 lower wiring pattern, 72 upper wiring pattern.

Claims

1. An oscillator array having a plurality of actual oscillators each having a plurality of actual piezoelectric layers and a dummy oscillator having a dummy piezoelectric layer; A ground film provided above the plurality of actual piezoelectric layers and the dummy piezoelectric layer, and electrically connected to a plurality of ground electrodes of the plurality of actual piezoelectric layers and the upper surface electrode of the dummy piezoelectric layer; A wiring sheet provided below the oscillator array, the wiring sheet having a plurality of signal lines electrically connected to a plurality of signal electrodes of the plurality of actual piezoelectric layers and a ground line electrically connected to the ground film; comprising the dummy oscillator has a conductive portion provided between the ground film and the wiring sheet and including the dummy piezoelectric layer, the ground film and the ground line are electrically connected through the conductive portion, characterized in that it is an ultrasonic probe.

2. In the ultrasonic probe according to Claim 1, the dummy piezoelectric layer has the upper surface electrode, a lower surface electrode, and side surface electrodes continuous with the upper surface electrode and the lower surface electrode, characterized in that it is an ultrasonic probe.

3. In the ultrasonic probe according to Claim 1, the plurality of actual oscillators each have a plurality of actual reflective layers having conductivity provided below the plurality of actual piezoelectric layers, the conductive portion has a dummy reflective layer having conductivity provided below the dummy oscillator, characterized in that it is an ultrasonic probe.

4. In the ultrasonic probe according to Claim 1, the oscillator array has a longitudinal direction, the width of the dummy oscillator in the longitudinal direction is larger than the width of each actual oscillator in the longitudinal direction, characterized in that it is an ultrasonic probe.

5. In the ultrasonic probe according to Claim 1, the oscillator array has an effective portion composed of the plurality of actual oscillators and a plurality of first slits for separating each actual oscillator from other actual oscillators, and a second slit provided between the effective portion and the dummy oscillator, comprising the oscillator array has a longitudinal direction, the width of the second slit in the longitudinal direction is larger than the width of each first slit in the longitudinal direction, characterized in that it is an ultrasonic probe.

6. In the ultrasonic probe according to Claim 1, the ground film has a film body having a plurality of strips electrically joined to the plurality of ground electrodes and the upper surface electrode, A pair of film ends connected to the plurality of strips, An ultrasonic probe characterized by including this.

7. In the ultrasonic probe according to Claim 1, The vibrator array has a longitudinal direction and a lateral direction intersecting the longitudinal direction, The wiring sheet is, A plurality of upper signal lines electrically connected to the plurality of signal electrodes of the plurality of active vibrators and arranged in the longitudinal direction, and an upper ground line electrically connected to the lower surface electrode of the dummy vibrator, an upper wiring pattern having; A lower wiring pattern having a plurality of lower signal lines arranged in the lateral direction and a lower ground line; A via group having a plurality of signal vias connecting the plurality of upper signal lines and the plurality of lower signal lines, and a ground via electrically connecting the upper ground line and the lower ground line; An ultrasonic probe characterized by including this.

8. In the ultrasonic probe according to Claim 7, The wiring sheet is, A sheet body provided below the vibrator array and having one end and the other end separated in the longitudinal direction; A first extension portion drawn out from the one end of the sheet body; A second extension portion drawn out from the other end of the sheet body; Including, The plurality of active vibrators are n active vibrators from the 1st active vibrator to the nth active vibrator arranged in numerical order in the longitudinal direction, The plurality of lower signal lines are, A first group of lower signal lines electrically connected to the odd-numbered active vibrators among the n active vibrators and provided across the sheet body and the first extension portion; A second group of lower signal lines electrically connected to the even-numbered active vibrators among the n active vibrators and provided across the sheet body and the second extension portion; An ultrasonic probe characterized by including this.

9. In the ultrasonic probe according to Claim 8, The plurality of signal vias are, A first signal via row connected to the first group of lower signal lines; A second signal via row connected to the second group of lower signal lines; Having, The first signal via row is aligned along the diagonal direction of the sheet body, The second signal via row is aligned along the diagonal direction while shifting from the first signal via row. An ultrasonic probe characterized by this.

10. In the ultrasonic probe according to Claim 1, A first assembly including the vibrator array, the ground film, and the wiring sheet; A backing provided below the first assembly and having a first end portion and a second end portion spaced apart in the longitudinal direction; A case that houses a second assembly including the first assembly and the backing; Including; The wiring sheet is; A sheet body provided below the vibrator array and having one end and the other end spaced apart in the longitudinal direction; A first extension portion drawn out from the one end of the sheet body; A second extension portion drawn out from the other side of the sheet body; Including; A lower space is formed below the backing in the case; The first extension portion enters the lower space through a space adjacent to the first end portion, and then turns in a U shape within the lower space; The second extension portion enters the lower space through a space adjacent to the second end portion; An end portion of the first extension portion and an end portion of the second extension portion overlap within the lower space; An ultrasonic probe characterized by the above.

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