Patent Application
20150119717
1. Technical Field
The present invention relates to an ultrasonic device, an ultrasonic probe head, an ultrasonic probe, an electronic apparatus, and an ultrasonic imaging apparatus.
2. Related Art
Ultrasonic devices using ultrasonic elements that transmit and receive ultrasound have been used in various applications. JP-A-2011-35916, which is an example of related art, discloses an ultrasonic endoscope provided with ultrasonic elements. This ultrasonic endoscope is provided with ultrasonic elements of the electrostatic capacitance type that transmit and receive ultrasound, and an acoustic lens that focuses the ultrasound.
The ultrasonic elements apply an AC voltage to a substrate on which a lower electrode is installed and a membrane on which an upper electrode is installed. This causes an electrostatic force to act on the substrate and the membrane, so that the membrane vibrates so that ultrasound is transmitted. The ultrasound passes through the acoustic lens, thereby being emitted so as to be focused on a predetermined point. The acoustic lens is formed using silicone resin, which is a material that easily transfers ultrasound to a material being examined and that is easily deformed due to a stress being applied.
An acoustic lens transmits ultrasound more easily when it is in contact with the material being examined. Further, since the position of the acoustic lens is controlled by an operator, the acoustic lens may be pressed by the material being examined in some cases. In JP-A-2011-35916, the periphery of the acoustic lens is supported by a metal package. Accordingly, when stress is applied to the acoustic lens by the material being examined, the center of the acoustic lens is easily deformed because it is held by its outer circumference. When the acoustic lens is deformed, the point on which the ultrasound is focused is shifted, and the sound pressure at the point on which the ultrasound was to be focused is reduced. Therefore, an ultrasonic device capable of transmitting and receiving ultrasound efficiently by suppressing the deformation of the acoustic lens has been desired.
The invention has been devised to solve the aforementioned problems and can be practiced as embodiments or application examples described below.
An ultrasonic device according to this application example includes: an ultrasonic element array substrate having a plurality of ultrasonic elements configured to perform at least one of transmission and reception of ultrasound; an acoustic lens configured to focus the ultrasound; an acoustic matching unit formed using resin, the acoustic matching unit being arranged between the ultrasonic element array substrate and the acoustic lens; and a plurality of columnar spacing members arranged between the ultrasonic element array substrate and the acoustic lens so as to be in contact with the ultrasonic element array substrate and the acoustic lens.
According to this application example, a plurality of ultrasonic elements are installed on the ultrasonic element array substrate. An ultrasonic element transmits or receives ultrasound. Alternatively, the ultrasonic element transmits and receives ultrasound. The ultrasound transmitted by the ultrasonic element passes through the acoustic matching unit and the acoustic lens to a material being examined. The acoustic matching unit adjusts the acoustic impedance between the acoustic lens and the ultrasonic element. This makes it difficult for ultrasound to be reflected by the interface between the acoustic lens and the ultrasonic element, and makes it difficult for ultrasound to be reflected by the interface between the acoustic matching unit and the acoustic lens. Accordingly, ultrasound is emitted efficiently to the material being examined.
The acoustic lens is used while in contact with the material being examined. At this time, the acoustic lens is pressed by the material being examined, and stress occurs inside the acoustic lens. The resin of the acoustic matching unit is susceptible to deformation, and therefore is deformed due to the stress of the acoustic lens. On the other hand, the columnar spacing members are in contact with the acoustic lens and the ultrasonic element array substrate, and transfer the stress of the acoustic lens to the ultrasonic element array substrate. Further, the thickness of the acoustic matching unit is kept constant, thereby suppressing the deformation of the acoustic lens so that ultrasound can be focused accurately. Further, ultrasound reflected by the material being examined also can be focused accurately on the ultrasonic element since the deformation of the acoustic lens is suppressed. As a result, the ultrasonic device can transmit and receive ultrasound efficiently.
In the ultrasonic device according to the aforementioned application example, the spacing members are arranged in locations that do not overlap with the ultrasonic elements in plan view, as viewed in a thickness direction of the ultrasonic element array substrate.
According to this application example, the spacing members are arranged at locations that do not overlap with the ultrasonic elements. The ultrasonic elements are overlapped by the ultrasonic matching unit formed of resin. Accordingly, the ultrasonic device can emit ultrasound whose acoustic impedance has been adjusted by the acoustic matching unit. Further, in the ultrasonic device, the acoustic matching unit can adjust the acoustic impedance of the received ultrasound and emit it to the ultrasound element.
In the ultrasonic device according to the aforementioned application example, the spacing members are arranged between the ultrasonic elements so as to extend in the form of a wall and hardly allow ultrasound to pass therethrough in an in-plane direction of the ultrasonic element array substrate.
According to the present example, the spacing members are arranged between the ultrasonic elements so as to extend in the form of a wall. The spacing members make it difficult for ultrasound to pass therethrough in the in-plane direction of the ultrasonic element array substrate and regulate the direction in which the ultrasound propagates. Note that the in-plane direction of the ultrasonic element array substrate is a direction parallel to the surface of ultrasonic element array substrate. Accordingly, it is possible to suppress a case in which ultrasonic elements located with a spacing member interposed therebetween influence each other when receiving and transmitting ultrasound.
In the ultrasonic device according to the aforementioned application example, the spacing members have lower water permeability than the acoustic matching unit and are arranged so as to cover wiring for transmitting an electrical signal to the ultrasonic elements.
According to this application example, the spacing members are arranged so as to cover the wiring. The spacing members are sites that have low water permeability and hardly allow moisture to pass therethrough. Accordingly, the spacing members suppress a case in which moisture attaches to the wiring, and therefore it is possible to prevent galvanic corrosion of the wiring.
In the ultrasonic device according to the aforementioned application example, a flow path through which material for the acoustic matching unit flows is formed between two of the spacing members.
According to this application example, the spacing members extend in the form of a wall. When the acoustic matching unit is to be formed, a flow path through which the material for the acoustic matching unit flows is formed between two spacing members. The material for the acoustic matching unit flows along the spacing members, and therefore the spaces between the spacing members can be filled tightly with the material for the acoustic matching unit.
In the ultrasonic device according to the aforementioned application example, the shape of the spacing members is circular or elliptical in plan view.
According to this application example, the shape of the spacing members is circular or elliptical. A circle or an ellipse has no corners, thereby allowing a fluid to flow along its outer circumference with little resistance. Accordingly, when the material for the acoustic matching unit is allowed to flow in the location where the spacing members are present, the material for the acoustic matching unit moves along the spacing members. At this time, the material for the acoustic matching unit pushes out the air located in the space for the acoustic matching unit, and therefore the intervals between the spacing members can be filled tightly with the material for the acoustic matching unit.
An ultrasonic probe head according to this application example includes: the ultrasonic device according to one of the aforementioned examples; and a housing configured to support the ultrasonic device.
According to this application example, the ultrasonic probe head includes the aforementioned ultrasonic device and the housing configured to support the ultrasonic device. The ultrasonic probe head of this application example includes the ultrasonic device that appropriately maintains the thickness of the acoustic matching unit, and that transmits and receives ultrasound efficiently. Accordingly, it is possible to provide the ultrasonic probe head that transmits and receives ultrasound efficiently.
An ultrasonic probe according to this application example includes: the ultrasonic device according to one of the aforementioned examples; and a driving circuit configured to drive the ultrasonic device.
According to this application example, the ultrasonic probe includes the aforementioned ultrasonic device and the driving circuit configured to drive the ultrasonic device. The ultrasonic probe of this application example includes the ultrasonic device that appropriately maintains the thickness of the acoustic matching unit, and that transmits and receives ultrasound efficiently. Accordingly, it is possible to provide the ultrasonic probe that transmits and receives ultrasound efficiently.
An electronic apparatus according to this application example includes: the ultrasonic device according to one of the aforementioned examples; and a processing unit connected to the ultrasonic device, the processing unit being configured to generate an image using an output of the ultrasonic device.
According to this application example, the electronic apparatus includes the aforementioned ultrasonic device and the processing unit. The processing unit generates image data using the output of the ultrasonic device. The electronic apparatus of this application example includes the ultrasonic device that appropriately maintains the thickness of the acoustic matching unit, and that transmits and receives ultrasound efficiently. Accordingly, it is possible to provide the electronic apparatus that transmits and receives ultrasound efficiently.
An ultrasonic imaging apparatus according to this application example includes: the ultrasonic device according to one of the aforementioned examples; and a processing unit connected to the ultrasonic device, the processing unit being configured to perform processing to generate an image using an output of the ultrasonic device; and a display unit configured to display the image.
According to this application example, the ultrasonic imaging apparatus includes the aforementioned ultrasonic device, the processing unit, and the display unit. The processing unit generates image data using the output of the ultrasonic device. The display unit displays images generated by the processing unit. The ultrasonic imaging apparatus of this application example includes the ultrasonic device that appropriately maintains the thickness of the acoustic matching unit, and that transmits and receives ultrasound efficiently. Accordingly, it is possible to provide the ultrasonic imaging apparatus that transmits and receives ultrasound efficiently.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
In this embodiment, characteristic examples of an an ultrasonic device and an ultrasonic probe and an ultrasonic imaging apparatus provided with the ultrasonic device will be described with reference to the drawings. It should be noted that the sizes of the members in the drawings are scaled differently in each figure so as to be perceptible.
In this embodiment, an ultrasonic imaging apparatus for examining an interior portion of a human body will be described as an example of an electronic apparatus with reference to
As shown in
In the apparatus body 2, an image is generated on the basis of ultrasound detected by the ultrasonic probe 3, and the detection results that are output as an image are displayed on the screen of the display unit 5. The ultrasonic probe 3 includes a rectangular parallelepiped housing 6. The cable 4 is connected to one end in the longitudinal direction of the housing 6. On the opposite side, a head portion 7 that transmits and receives ultrasound is provided. It should be noted that a configuration of the ultrasonic imaging apparatus 1 is used in which the apparatus body 2 and the ultrasonic probe 3 are connected by the cable 4. A configuration is also possible in which the apparatus body 2 and the ultrasonic probe 3 wirelessly exchange signals without using the cable 4.
As shown in
As shown in
An FPC 13 (Flexible Printed Circuit) that connects the ultrasonic device 9 to a processing circuit is interposed between the adhesive member 11 and the adhesive member 12. The FPC 13 is fixed by being sandwiched by the adhesive member 11 and the adhesive member 12. The FPC 13 is referred to also as flexible printed circuit board. As the adhesive member 11 and the adhesive member 12, a double-sided adhesive tape formed by applying an acrylic-based adhesive material to a closed cell foam material such as polyethylene or urethane can be used, for example. In this way, a double sealing structure is employed for the ultrasonic probe 3, in which the sealing portion 10, the adhesive member 11, and the adhesive member 12 prevent moisture, dust, and the like from entering the inside of the housing 6.
The ultrasonic device 9 includes an ultrasonic element array substrate 14, an acoustic matching unit 15, an acoustic lens 16, the FPC 13, and a frame 17 as a fixing frame. The ultrasonic element array substrate 14 has an element substrate 18 and a back plate 21. The element substrate 18 is a substrate on which a plurality of ultrasonic elements are arranged in an array on a surface on the −Z direction side, and has a rectangular shape elongated in the X direction, in plan view as viewed from the Z direction. The element substrate 18 is formed using a silicon substrate and has a thickness of about 150 μm to 200 μm. The back plate 21 having the same flat plate shape as the element substrate 18 is adhered to the opposite surface of the element-formed surface of the element substrate 18 oriented in the −Z direction. The back plate 21 serves to suppress excess vibration of the element substrate 18 and absorb ultrasound. A silicon substrate with a thickness of 500 μm to 600 μm is used for the back plate 21. For the back plate 21, a metal plate may be used, rather than such a silicon substrate. In the case where the influence of ultrasound that travels in the Z direction from the element substrate 18 is small, the ultrasonic device 9 may be formed without using the back plate 21.
On the surface of the element substrate 18 on which the ultrasonic elements are formed, a plurality of terminals connected to the plurality of ultrasonic elements are installed along the long edge extending in the X direction, in plan view. These terminals are connected to the terminals of the FPC 13 and are thus connected electrically as well.
On the surface of the element substrate 18 on which the ultrasonic elements are formed, the acoustic lens 16 is arranged. The planar shape of the acoustic lens 16 as viewed from the −Z direction is the same as the shape of the ultrasonic element array substrate 14. On the acoustic lens 16, a lens portion 22 is provided. The lens portion 22 has a surface facing the −Z direction that protrudes in the thickness direction with a predetermined curvature. On the surface facing the Z direction, a wall 23 that projects in the thickness direction and that is formed on the outer edge portion of the acoustic lens 16 is provided. The acoustic lens 16 is formed using a resin such as silicone resin. It is possible to adjust the acoustic impedance of the silicone resin by adding silica, or the like, to the silicone resin to change the specific gravity of the silicone resin.
The acoustic matching unit 15 is formed between the ultrasonic element array substrate 14 and the acoustic lens 16. For the acoustic matching unit 15, a silicone-based adhesive material is used. Curing of the adhesive material causes the ultrasonic element array substrate 14 and the acoustic lens 16 to be secured (adhered) to each other. The thus cured adhesive material (resin) functions as the acoustic matching unit 15. A plurality of columnar spacing members 24 are installed in parallel with the acoustic matching unit 15. The spacing members 24 keep the thickness of the acoustic matching unit 15 constant. When the acoustic lens 16 is pressed by a target object, the spacing members 24 transfer the force applied onto the acoustic lens 16 to the ultrasonic element array substrate 14. The spacing members 24 suppress the deformation of the acoustic lens 16 due to a reaction force received from the ultrasonic element array substrate 14.
The acoustic lens 16 serves to focus ultrasound transmitted from the ultrasonic elements of the element substrate 18 and guide them efficiently to a target object. The acoustic lens 16 also serves to guide echo waves reflected back from the object efficiently to the ultrasonic elements. The acoustic matching unit 15 serves to relax the acoustic impedance mismatch between the acoustic lens 16 and the ultrasonic elements. The back plate 21 of the ultrasonic device 9 is fixed to the support member 8 by an adhesive material 25.
The transmitting circuit 28 outputs transmission signals VT to the ultrasonic device 9 via the selection circuit 27 in a transmission period. Specifically, the transmitting circuit 28 generates the transmission signals VT, on the basis of control by the control unit 30, and outputs them to the selection circuit 27. Then, the selection circuit 27 outputs the transmission signals VT from the transmitting circuit 28, on the basis of control by the control unit 30. The frequency and amplitude voltage of the transmission signals VT are set by the control unit 30.
The receiving circuit 29 performs reception processing to receive reception signals VR from the ultrasonic device 9. Specifically, the receiving circuit 29 receives the reception signals VR from the ultrasonic device 9 via the selection circuit 27 in a reception period. The receiving circuit 29 performs reception processing such as amplification of the reception signals, gain setting, frequency setting, and A/D conversion (analog/digital conversion). The receiving circuit 29 outputs the results of the reception processing to the apparatus body 2 as detected data (detected information). The receiving circuit 29, for example, can be composed of a low-noise amplifier, a voltage-controlled attenuator, a programmable gain amplifier, a low-pass filter, an A/D converter, and the like.
The control unit 30 controls the transmitting circuit 28 and the receiving circuit 29. Specifically, the control unit 30 controls the transmitting circuit 28 for generation of the transmission signals VT and output processing, and controls the receiving circuit 29 for frequency setting of the reception signals VR, gain, or the like. The selection circuit 27 outputs the selected transmission signals VT to the ultrasonic device 9, on the basis of control by the control unit 30.
The apparatus body 2 includes the display unit 5, a main control unit 31, a processing unit 32, and a UI unit 33 (user interface unit). The main control unit 31 controls the ultrasonic probe 3 for transmission and reception of ultrasound, and controls the processing unit 32 for image processing of detected data, for example. The processing unit 32 receives detected data from the receiving circuit 29, and performs image processing to remove noises, generation of image data to be displayed, or the like. The UI unit 33 includes a function of receiving input of a user instruction, and the UI unit 33 outputs necessary instruction (command) to the main control unit 31 on the basis of operation (such as touch panel operation) by the user. The display unit 5, for example, is a liquid crystal display, and receives input of the image data to be displayed from the processing unit 32 and displays it. It should be noted that part of control by the main control unit 31 may be performed by the control unit 30 of the processing circuit 26, or part of control by the control unit 30 may be performed by the main control unit 31.
As shown in
The frame 17 is composed of an inner frame 34 located on the inner side and an outer frame 35 located on the outer side. The inner frame 34 presses the acoustic lens 16 from the −Z direction side. The outer frame 35 presses the ultrasonic element array substrate 14 from the Z direction side. The inner frame 34 and the outer frame 35 are adhered to each other so as to be secured. Accordingly, the frame 17 fixes the ultrasonic element array substrate 14, the acoustic matching unit 15, and the acoustic lens 16 by sandwiching them in the Z direction.
The spacing members 24 are installed in parallel with the acoustic matching unit 15. The spacing members 24 are arranged between the ultrasonic element array substrate 14 and the acoustic lens 16 that are sandwiched by the frame 17. The frame 17 reliably fixes the ultrasonic element array substrate 14 and the acoustic lens 16 by sandwiching them with the spacing members 24 interposed therebetween. Accordingly, the spacing members 24 can keep the thickness of the acoustic matching unit 15 constant.
A first recessed portion 23c is formed in the X direction of the wall 23, and a third recessed portion 23e is formed in the −X direction thereof. The first recessed portion 23c and the third recessed portion 23e are continuous with the acoustic matching unit 15 in a location opposing the lens unit 22. The acoustic matching unit 15 is located also inside the first recessed portion 23c and the third recessed portion 23e.
Second recessed portions 23d are formed in the Y direction of the wall 23, and fourth recessed portions 23f are formed on the −Y direction thereof. The second recessed portions 23d and the fourth recessed portions 23f are continuous with the acoustic matching unit 15 at a location opposing the lens 22. The acoustic matching unit 15 is located also inside the second recessed portions 23d and the fourth recessed portions 23f.
The spacing members 24 are located in the first recessed portion 23c and the third recessed portion 23e. The spacing members 24 are arranged between the ultrasonic element array substrate 14 and the acoustic lens 16 in a portion sandwiched by the frame 17 in plan view, as viewed from the −Z direction. The frame 17 sandwiches the ultrasonic element array substrate 14 and the acoustic lens 16 with the spacing members 24 interposed therebetween, and therefore the spacing members 24 can reliably keep the thickness of the acoustic matching unit 15 constant.
The FPC 13 is sandwiched by the ultrasonic element array substrate 14 and the wall 23 on the Y direction side and the −Y direction side of the acoustic lens 16. The frame 17 holds the ultrasonic element array substrate 14 and the wall 23 by sandwiching them, thereby preventing the FPC 13 from lifting in a portion where the ultrasonic element array substrate 14 and the FPC 13 are connected to each other. Thus, the FPC 13 is reliably fixed.
Letting X be the wavelength of the ultrasound to be used, the thickness of the acoustic matching unit 15 is set to an odd multiple of ¼λ. The thickness of the spacing members 24 in the Z direction is set equal to the thickness of the acoustic matching unit 15.
An opening 37a is formed in the base substrate 37 made of a silicon substrate, or the like, and the ultrasonic element 36 includes the vibrating membrane 38 that covers the opening 37a so as to close it. The vibrating membrane 38 is composed of a double layer structure, for example, of a SiO2 layer and a ZrO2 layer. In the case where the base substrate 37 is a silicon substrate, the SiO2 layer can be formed by subjecting the surface of the substrate to a thermal oxidation treatment. Further, the ZrO2 layer can be formed on the SiO2 layer, for example, by a technique such as sputtering. For example, in the case of using PZT (lead zirconate titanate) as the piezoelectric layer 43, the ZrO2 layer is a layer for preventing Pb that constitutes the PZT from diffusing into the SiO2 layer. Further, the ZrO2 layer also has an effect of improving the warpage efficiency corresponding to distortion of the piezoelectric layer, etc.
The first electrode 42 is formed on the vibrating membrane 38. The piezoelectric layer 43 is formed on the first electrode 42. The second electrode 44 is formed further on the piezoelectric layer 43. That is, the piezoelectric body 41 has a structure in which the piezoelectric layer 43 is sandwiched between the first electrode 42 and the second electrode 44.
The first electrode 42 is formed of a thin metal film, and extends in the Y direction. A portion thereof protrudes in the X direction at the ultrasonic element 36. The first electrode 42 is arranged over a plurality of piezoelectric bodies 41, and functions also as wiring. The portion of the first electrode 42 that functions as wiring will be referred to as “first line 42a”. The piezoelectric layer 43 is formed, for example, of a thin PZT (lead zirconate titanate) film, and is provided to cover part of the first electrode 42. It should be noted that the material of the piezoelectric layer 43 is not limited to PZT. For example, lead titanate (PbTiO3), lead zirconate (PbZrO3), lead lanthanum titanate ((Pb, La) TiO3), or the like, may be used. The second electrode 44 is formed of a thin metal film, and is provided to cover the piezoelectric layer 43. The second electrode 44 extends in the Y direction, and a portion thereof protrudes in the −X direction at the ultrasonic element 36. The second electrode 44 is arranged over the plurality of piezoelectric bodies 41, and functions also as wiring. The portion of the second electrode 44a that functions as wiring will be referred to as “second line 44a”.
When the element substrate 18 is viewed from the −Z direction, the first electrode 42 and the second electrode 44 overlap each other at the ultrasonic element 36. The first line 42a and the second line 44a are portions at which the first electrode 42 and the second electrode 44 do not overlap. The spacing members 24 are arranged in locations where the first line 42a and the second line 44a are installed. The spacing members 24 are installed in locations that do not overlap with the ultrasonic elements 36. The acoustic matching unit 15 is installed so as to overlap the ultrasonic elements 36. The spacing members 24 do not need to be arranged in all locations that do not overlap with the ultrasonic elements 36, and it is sufficient to provide the spacing members 24 in some locations. The spacing members 24 may be provided in an amount such that the thickness of the acoustic matching unit 15 can be kept constant.
An insulation film 45 that prevents moisture permeation from the outside and insulates the acoustic matching unit 15 from the first electrode 42 and the second electrode 44 is provided to cover the ultrasonic element 36. The insulation film 45 is formed of a material such as alumina, and is provided entirely or partially on the surface of the ultrasonic element 36. Further, the insulation film 45 is arranged to cover the first electrode 42 and the second electrode 44.
The piezoelectric layer 43 expands and contracts in the in-plane direction due to a voltage applied between the first electrode 42 and the second electrode 44. Accordingly, when a voltage is applied to the piezoelectric layer 43, convex warpage occurs on the opening 37a side, so that the vibrating membrane 38 is deflected. Application of an AC voltage to the piezoelectric layer 43 causes the vibrating membrane 38 to vibrate in the membrane thickness direction, and the vibration of the vibrating membrane 38 causes ultrasound to be emitted from the opening 37a. The voltage (drive voltage) to be applied to the piezoelectric layer 43, for example, is 10 to 30 V from peak to peak, and the frequency thereof, for example, is 1 to 10 MHz.
The ultrasonic element 36 acts also as a receiving element to receive ultrasonic echo of the emitted ultrasound that is reflected by the target object and returns back. The ultrasonic echo vibrates the vibrating membrane 38, and stress is applied to the piezoelectric layer 43 due to this vibration, thereby generating a voltage between the first electrode 42 and the second electrode 44. This voltage can be output as a reception signal.
During the transmission period in which ultrasound is emitted, the transmission signals VT output by the processing circuit 26 are supplied to the respective ultrasonic elements 36 via the second electrode 44. Meanwhile, during the reception period in which ultrasonic echo signals are received, the reception signals VR from the ultrasonic elements 36 are output to the processing circuit 26 via the second electrode 44. The first electrode 42 is supplied with a common voltage VCOM. It is sufficient that this common voltage is a constant voltage, and it need not be 0 V, or in other words, a ground potential. In the transmission period, a voltage that is the difference between the transmission signal voltage and the common voltage is applied to each of the ultrasonic elements 36, and ultrasound is emitted at a predetermined frequency.
The spacing members 24 are installed in the location where the first recessed portion 23c of the acoustic lens 16 is located, along an edge of the element substrate 18 on the X direction side. Similarly, the spacing members 24 are installed also in the location where the third recessed portion 23e of the acoustic lens 16 is located, along an edge of the element substrate 18 on the—X direction side. When the frame 17 sandwiches the acoustic lens 16 and the ultrasonic element array substrate 14, the spacing members 24 receive the load in a portion close to the frame 17, which enables the thickness of the acoustic matching unit 15 to be kept constant.
Next, a method for manufacturing the aforementioned ultrasonic device 9 will be described with reference to
Step S5 corresponds to a lens installation step. In this step, the acoustic lens 16 is installed so as to overlap the ultrasonic element array substrate 14. Next, the process proceeds to step S6. Step S6 corresponds to an acoustic matching unit solidification step. In this step, the acoustic matching unit is solidified. Next, the process proceeds to step S7. Step S7 corresponds to a frame installation step. In this step, the frame 17 is installed so as to sandwich the ultrasonic element array substrate 14 and the acoustic lens 16. By performing the aforementioned steps, the ultrasonic device 9 is achieved.
Next, with reference to
The shape of the spacing members 24 is circular or elliptical in plan view as viewed from the −Z direction. Such a circular or elliptical shape has no corners, thereby allowing a fluid to flow with a low resistance along its outer circumference. Accordingly, when the acoustic matching member 46 is allowed to flow in the location where the spacing members 24 are present, the acoustic matching member 46 moves along the spacing members 24. At this time, the acoustic matching member 46 pushes out the air located in the space between the ultrasonic element array substrate 14 and the acoustic lens 16, and therefore the intervals of the spacing members 24 can be filled tightly with the acoustic matching member 46.
The acoustic matching member 46 overflowing from the space between the ultrasonic element array substrate 14 and the acoustic lens 16 may be removed with a spatula or the like. It is also possible to adjust the amount of the acoustic matching member 46 to be applied so that the acoustic matching member 46 does not overflow from the space between the ultrasonic element array substrate 14 and the acoustic lens 16.
An adhesive material is applied to the outer side surface of the inner frame 34 in step S7. Next, the inner frame 34 is inserted from the −Z direction side so as to fit the ultrasonic element array substrate 14 and the acoustic lens 16. Next, the outer frame 35 is inserted from the Z direction side to fit the inner frame 34. Next, the adhesive material between the inner frame 34 and the outer frame 35 is solidified so that the inner frame 34 and the outer frame 35 are adhered to each other. At this time, it is preferable that a load is applied in a manner such that the inner frame 34 and the outer frame 35 sandwich the ultrasonic element array substrate 14 and the acoustic lens 16. This allows the ultrasonic element array substrate 14 and the acoustic lens 16 to be fixed with an accurate spacing therebetween. By performing the aforementioned steps, the ultrasonic device 9 is achieved.
As described above, this embodiment has the following effects.
(1) According to this embodiment, the acoustic lens 16 is used in contact with the material being examined. At this time, the acoustic lens 16 is pressed by the material being examined. Stress occurs inside the acoustic lens 16. The acoustic matching unit 15 made of resin, which is susceptible to deformation, deforms due to the stress of the acoustic lens 16. On the other hand, the columnar spacing members 24 are in contact with the acoustic lens 16 and the ultrasonic element array substrate 14 so as to transfer the stress of the acoustic lens 16 to the ultrasonic element array substrate 14. Thus, the thickness of the acoustic matching unit 15 is kept constant, thereby suppressing the deformation of the acoustic lens 16, so that ultrasound can be accurately focused. Further, ultrasound reflected by the material being examined also can be accurately focused on the ultrasonic element 36 since the deformation of the acoustic lens 16 is suppressed. As a result, the ultrasonic device 9 can transmit and receive ultrasound efficiently.
(2) According to this embodiment, the spacing members 24 are installed in locations that do not overlap with the ultrasonic elements 36. Accordingly, the ultrasonic elements 36 are overlapped by the ultrasonic matching unit 15 formed of resin. Accordingly, the ultrasonic device 9 can emit ultrasound with an acoustic impedance adjusted by the acoustic matching unit 15. Further, in the ultrasonic device 9, the acoustic matching unit 15 can adjust the acoustic impedance of the received ultrasound and emit it to the ultrasound element 36.
(3) According to this embodiment, the shape of the spacing members is circular or elliptical. A circle or an ellipse has no corners, thereby allowing a fluid to flow along its outer circumference with little resistance. Accordingly, when the acoustic matching member 46 is allowed to flow in the location where the spacing members 24 are present, the acoustic matching member 46 moves along the arrangement of the spacing members 24. At this time, the acoustic matching member 46 pushes out the air located in the space between the ultrasonic element array substrate 14 and the acoustic lens 16, and therefore the intervals between the spacing members 24 can be filled tightly with the acoustic matching member 46.
Next, an embodiment of an ultrasonic device will be described with reference to
In this embodiment, the ultrasonic device 49 includes an element substrate 50, as shown in
The spacing member 51 hardly allows ultrasound to pass therethrough, and is arranged between ultrasonic elements that are adjacent to each other in the X direction, so as to extend in the form of a wall. It is difficult for ultrasound to pass through the spacing member 51, and the spacing member 51 regulates the direction in which ultrasound propagates. Accordingly, it is possible to suppress a case in which the ultrasonic elements 36 located in the X direction with the spacing member 51 interposed therebetween influence each other via ultrasound.
The spacing member 51 is formed using a material that has low water permeability and hardly allows moisture to pass therethrough. For example, epoxy resin can be used as a material of the spacing member 51. The spacing member 51 is arranged so as to cover the first line 42a and the second line 44a. Accordingly, the spacing member 51 suppresses a case in which moisture attaches to the first line 42a and the second line 44a, and thus can prevent the galvanic corrosion of the first line 42a and the second line 44a.
As shown in
The spacing members 51 constitute flow paths through which the acoustic matching member 46 flows. The acoustic matching member 46 moves along the spacing members 51, and therefore pushes out air bubbles, thereby allowing the intervals of the spacing members 51 to be filled tightly with the acoustic matching member 46.
As described above, this embodiment has the following effects.
(1) According to this embodiment, the spacing member 51 is arranged between the ultrasonic elements 36, so as to extend in the form of a wall. It is difficult for ultrasound to pass through the spacing member 51, and the spacing member 51 regulates the direction in which ultrasound propagates. Accordingly, it is possible to suppress a case in which the ultrasonic elements 36 located with the spacing member 51 interposed therebetween influence each other via ultrasound.
(2) According to this embodiment, the spacing member 51 is arranged so as to cover the first line 42a and the second line 44a. The spacing member 51 has a structure that hardly allows moisture to pass therethrough. Accordingly, the spacing member 51 suppresses a case in which moisture attaches to the first line 42a and the second line 44a, and thus can prevent the galvanic corrosion of the first line 42a and the second line 44a.
(3) According to this embodiment, the spacing members 51 form flow paths through which the acoustic matching member 46 flows. The acoustic matching member 46 moves along the spacing members 51, and thus the air between the spacing members 51 is pushed out by the acoustic matching member 46. As a result, the intervals of the spacing members 51 can be filled tightly with the acoustic matching member 46.
Next, an embodiment of an ultrasonic probe will be described with reference to
As shown in
The probe head 56 includes a head housing 59 as a housing, and the ultrasonic device 9 is incorporated in the head housing 59. The acoustic lens 16 of the ultrasonic device 9 is exposed from the head housing 59. A second connector 60 connected to the first connector 58 is installed in the head housing 59, and the processing circuit 26 and the ultrasonic device 9 are electrically connected to each other via the first connector 58 and the second connector 60.
As shown in
As described above, this embodiment has the following effects.
(1) According to this embodiment, the probe head 56 includes the ultrasonic device 9 and the head housing 59 supporting the ultrasonic device 9. The ultrasonic probe 54 includes the ultrasonic device 9 that appropriately maintains the thickness of the acoustic matching unit 15, and that transmits and receives ultrasound efficiently. Accordingly, it is possible to provide the ultrasonic probe 54 that transmits and receives ultrasound efficiently.
(2) According to this embodiment, the probe head 54 of the ultrasonic probe 56 can be exchanged. Accordingly, it is possible to exchange it with an ultrasonic device 9 that is suitable for the acoustic impedance or the portion of the material being examined.
Next, an embodiment of an ultrasonic imaging apparatus will be described with reference to
As shown in
The invention is not limited to the foregoing embodiments. The specific arrangements and procedures in practicing the invention may be altered by another arrangement or the like as necessary as long as the objects of the invention can be achieved. Many modifications can be made by a person of ordinary skill in the art without departing from the technical scope of the invention. Examples of the modifications will be described below.
Modification 1
In the first embodiment, the spacing members 24 are circular or elliptical. However, there is no limitation on the shape of the spacing members 24. They may be in various forms such as a cone, elliptic cone, cube, rectangular parallelepiped, triangular prism, and polyhedral prism. The shape of the spacing members 24 can be selected so as to facilitate the manufacture thereof.
Modification 2
In the first embodiment, the ultrasonic element 36 performs both the transmission and reception of ultrasound. It is also possible to separate an element that performs the transmission of ultrasound from an element that performs the reception of ultrasound. Further, it is also possible to provide an element that performs the transmission of ultrasound, an element that performs the reception of ultrasound, and an element that performs the transmission and reception of ultrasound. They may be combined depending on the accuracy requirements in the transmission and reception of ultrasound.
In the first embodiment, the piezoelectric layer 43 is a thin film formed using a photolithographic technique. The piezoelectric layer 43 may be of a thick bulk type. Also in this case, the spacing members 24 keep the thickness of the acoustic matching unit 15 constant, which can make the deformation of the acoustic lens 16 difficult, even if the acoustic lens 16 is pressed.
Modification 3
In the second embodiment, the spacing member 51 is in the form of a continuous rectangular parallelepiped that extends in the Y direction so as to cover the first line 42a and the second line 44a. The spacing member 51 may be divided into multiple parts in the Y direction. The acoustic matching member 46 can be allowed to flow so as to fill the spaces between the spacing members 51.
The entire disclosure of Japanese Patent Application No. 2013-223009, filed Oct. 28, 2013 is expressly incorporated by reference herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-223009 | Oct 2013 | JP | national |
