Ultrasonic transducer, manufacturing method thereof, and ultrasonic probe

The purpose is to provide an ultrasonic transducer and ultrasonic probe without the complexity of the manufacturing process of a non-conductive acoustic matching layer while ensuring the conductive path. In the non-conductive acoustic matching layer comprising the first surface of the electrode side and the second surface of the opposite side of the piezoelectrics, a plurality of first grooves leading up to the mid-way point between the first surface and the second surface are arranged on each of the first surfaces of the non-conductive acoustic matching later in response to the arrangement of sound elements. Moreover, each of the second surfaces is provided with the plurality of second grooves leading up to at least the mid-way point from the second surface, intersecting the first grooves.

FIELD OF THE INVENTION

The embodiment of the present invention relates to an ultrasonic transducer, the manufacturing method thereof, and an ultrasonic probe.

BACKGROUND OF THE INVENTION

An ultrasonic probe comprises a plurality of piezoelectrics. Moreover, electrodes are arranged on both sides of the piezoelectronics such that they interleave the piezoelectronics. There are various ways of guiding electrodes regarding the piezoelectronics. For example, one method involves conducting electrodes arranged in front surface, which is the surface of the ultrasonic radiation direction side of the piezoelectrics, with FPC (Flexible Printed Circuits). Signals derived from FPC are transmitted to a transmitter-receiver circuit.

Generally, the acoustic impedance of body tissues is approximately 1.5 Mrayl. Moreover, the acoustic impedance of piezoelectrics is 30 Mrayl or more. In other words, there is a large difference in impedance between body tissues and piezoelectrics. Therefore, acoustic mismatching occurs when body tissues are directly contacted to piezoelectrics. As a result, ultrasonic beams are reflected at borders with greatly different acoustic impedance. Accordingly, an acoustic matching layer is necessary between body tissues and piezoelectrics. The acoustic matching layer is an intermediate layer that efficiently propagates ultrasonic waves.

Moreover, in order to reduce and alleviate the acoustic mismatching mentioned above, a plurality of acoustic matching layers is sometimes configured. In the configuration, a plurality of acoustic matching layers with different acoustic impedance between the acoustic impedance of the body tissue (for example, 1.5 Mrayl) and the acoustic impedance of piezoelectrics (for example, 30 Mrayl) is gradually layered.

In the configuration, for example, if the acoustic impedance of first layer in the acoustic matching layer is approximately 9 to 15 Mrayl, a machinable ceramic is used as a material with such acoustic impedance. Machinable ceramics are mainly composed of mica and are non-conductive material.

Here, a driving voltage must be applied to the piezoelectrics in order to transmit ultrasonic waves. The electrode provided to the piezoelectrics and the driving circuit of the ultrasonic diagnostic equipment are connected using cables, etc., in order to apply the driving voltage. Moreover, when receiving ultrasonic waves, the received signals must be extracted from the piezoelectrics. In order to extract the received signals, the electrode of the piezoelectrics and the driving circuit of the ultrasonic diagnostic equipment are connected using cables, etc. As a principle measure for electrically connecting with piezoelectrics, one method uses an electrode pattern formed on substrates with relatively small acoustic impedance. FPCs are mainly used as the substrate. However, mismatching occurs when the FPCs are directly connected to the electrode of the piezoelectrics. For example, if the acoustic impedance value of the FPCs is approximately 3 Mrayl, as mentioned above, nonconformity of the acoustic impedance occurs between the body tissues and the piezoelectrics. Accordingly, the FPCs must be established via several acoustic matching layers mentioned above. When arranging the non-conductive acoustic matching layer on the first layer, the non-conductive acoustic matching layer is present between the electrode of the piezoelectrics and the electrode on the FPCs, consequently electrical connection is not performed. That is, a conductive path must be provided on the non-conductive acoustic matching layer.

For example, in a two-dimensional array ultrasonic transducer, electrodes must be derived to the FPCs from each of a huge number of elements. Accordingly, in conventional ultrasonic transducers, a through hole is formed with respect to the non-conductive acoustic matching layer, the through hole comprising electric conductivity provided in correspondence with the number and arrangement of the piezoelectrics in the layering direction. In the ultrasonic transducer, the same number of through holes as the piezoelectrics is formed on the acoustic matching layer, and the conductive path is secured by, for example, plating the entire surface of the through holes.

Moreover, in the conventional manufacturing method of ultrasonic transducers, a conductive film is provided on both surfaces of the board of the non-conductive material, and the acoustic matching layer is formed by overlapping both surfaces of the conductive film of the board thereof. That is, the non-conductive material formed by overlapping the surfaces of the conductive film of the board comprises the conductive path toward the layering direction. As an example, a board of non-conductive material having the same width as the pitch of piezoelectrics is formed, with the conductive film provided on both surfaces thereof. The boards are overlapped in a number corresponding to the number of columns or rows of the piezoelectrics to form several blocks. Furthermore, the blocks are further overlapped to form the acoustic matching layer. In the acoustic matching layer formed by the process, the board and a superposed plane of the board function as the conductive path of the electrode and the FPC.

PRIOR ART DOCUMENTS

Patent Documents

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

However, according to the manufacturing method, the manufacturing process becomes complicated. Moreover, alignment is difficult, resulting in high manufacturing costs. For example, in the process of manufacturing the through holes in correspondence with the number and arrangement of the piezoelectrics, there is a risk of the cost being increased, and moreover, the operation involving ensuring the accuracy of the through hole position is difficult. Moreover, the manufacturing process of the acoustic matching layer involving providing the conductive film on the board configured from the non-conductive material and then overlapping this is complicated, with a danger of causing further increase in the manufacturing cost and lead time in the manufacturing process of the acoustic matching layer.

The purpose of this embodiment is to provide an ultrasonic transducer that may ensure a conductive path between the substrate and the electrode of the piezoelectrics while avoiding complications in the manufacturing process of the non-conductive acoustic matching layer, as well as the manufacturing method and ultrasonic probe thereof.

Means of Solving the Problem

The ultrasonic transducer related to this embodiment comprises a plurality of piezoelectrics, electrodes provided to each of the piezoelectrics, a non-conductive acoustic matching layer, and a substrate. The piezoelectrics are two-dimensionally arranged. Furthermore, the non-conductive acoustic matching layer comprises a first surface of the electrode side and a second surface, which is the opposite side of the first surface. The substrates are arranged on the second surface side. A plurality of first grooves leading up to the mid-way point between the first surface and the second surface are respectively arranged on the first surface of the non-conductive acoustic matching layers divided according to the sequence of sound elements. Moreover, each of the second surfaces of the non-conductive acoustic matching layer are provided with a plurality of second grooves leading up to at least the mid-way point from the second surface that intersects with the first grooves. The electrode and the second surface of the non-conductive acoustic matching layer are conducted via the first grooves, the crossing part (intersection) of the first grooves and the second grooves, and the second grooves.

MODE FOR CARRYING OUT THE INVENTION

In the following, the ultrasonic transducer and the ultrasonic probe related to the present embodiment are described with reference toFIGS. 1 to 18.

(Schematic Configuration of the Ultrasonic Transducer)

The outline of an ultrasonic transducer100related to Embodiment 1 is described with reference toFIGS. 1 to 3.FIG. 1is a schematic perspective view showing the outline of the ultrasonic transducer100. The schematic configuration of the ultrasonic transducer100related to the present embodiment is described in the following. Furthermore, the number of sequences of the piezoelectrics114of the ultrasonic transducer100shown inFIG. 1is shown as a concept. Moreover, the illustrated shape of the entire arrangement, for example, the number of columns and number of rows in the two-dimensional array, is no more than one example, and other configurations may be applied.

Moreover, in the description below, the direction from a backing material118to a conductive acoustic matching layer111is referred to as the “front” (z direction inFIG. 1). The direction of the front and the opposite side is referred to as the “rear.” Moreover, the front side surface of each component part in the ultrasonic transducer100is referred to as the “front surface.” The surface of the rear side is referred to as the “back surface.” Furthermore, the front surface of the non-conductive acoustic matching layer110corresponds to an example of “the second surface,” while the back surface corresponds to an example of “the first surface.”

As shown inFIG. 1, in the ultrasonic transducer100related to this embodiment, the piezoelectrics114are two-dimensionally arranged on the xy surface. Moreover, the non-conductive acoustic matching layer110is provided corresponding to each front surface of the respective piezoelectrics114. Furthermore, the conductive acoustic matching layer111is provided on the front surface side of the non-conductive acoustic matching layer110. Moreover, the backing material (material load phase)118is provided on the back surface side of the piezoelectrics114, with a rear substrate120provided between the backing material118and the piezoelectrics114. Moreover, in the ultrasonic transducer100, the rear substrate120is derived on at least the circuit side of a subsequent stage such as a transmitter-receiver circuit; however, inFIG. 1, an illustration of the section of the rear substrate120is omitted.

Moreover, as shown inFIG. 1, a front substrate122is provided on the front surface side of the conductive acoustic matching layer111. An acoustic lens (not illustrated) is further provided on the front surface of the front substrate122. Moreover, in the same manner as the rear substrate120, an illustration of the part extending to the circuit of the subsequent stage is also omitted from the front substrate122ofFIG. 1. Moreover, a front surface electrode112is provided on the front surface side of the piezoelectrics114. The front surface electrode112is adjacent to the back surface of the non-conductive acoustic matching layer110. Furthermore, a back surface electrode116is provided on the back surface side of the piezoelectrics114.

(Configuration of Each Part)

The configuration of each part in the ultrasonic transducer100related to Embodiment 1 is described in the following.

The piezoelectrics114convert the voltage applied to the back surface electrode116and the front surface electrode112into an ultrasonic pulse. The ultrasonic pulse is wave-transmitted to a subject as a test object of the ultrasonic diagnostic equipment. Moreover, the piezoelectrics114receive a reflected wave from the subject and convert this into voltage. As the material of the piezoelectrics114, generally, PZT (lead zirconate titanate/Pb (Zr,Ti) O3), barium titanate (BaTiO3), PZNT (Pb (Zn⅓Nb⅔) O3-PbTiO3) single crystal, PMNT (Pb (Mg⅓Nb⅔) O3-PbTiO3) single crystal, etc., may be used. The acoustic impedance of the piezoelectrics114is, for example, approximately 30 Mrayl. Furthermore, although the piezoelectrics114inFIG. 1are configured as a single layer, they may also be configured as multiple layered piezoelectrics114.

The backing material118absorbs the ultrasonic pulse emitted in the irradiation direction of the ultrasonic wave and the opposite side (rear) when wave-transmitting the ultrasonic pulse, suppressing excess vibrations of the respective piezoelectrics114. By means of the backing material118, reflection from the back surface of the respective piezoelectrics114during vibration may be suppressed. In other words, by means of the backing material118, any negative influence caused during transmission and receiving of the ultrasonic pulse may be avoided. Moreover, as the backing material118, from the perspective of acoustic attenuation, acoustic impedance, etc., any materials such as an epoxy resin containing PZT powder, tungsten powder, etc., rubber filled with polyvinyl chloride and/or ferrite powder, or porous ceramic impregnated with resin such as epoxy, etc. may be used.

As the front substrate122and the rear substrate120, for example, a FPC (Flexible Printed Circuits) may be used. Moreover, the front substrate122and the rear substrate120are each of a length leading to the circuit of the subsequent stage of the transmitter-receiver circuit or a connection of the cable, etc. Moreover, each of the front substrate122and the rear substrate120are provided with a connecting lead (not illustrated) connected to the circuit of the subsequent stage. The connecting lead is provided on one or both of the front surface side and the back surface side of each of the front substrate122and the rear substrate120. Regarding the front substrate122and the rear substrate120of this example, for example, polyimides are used as the base material. The acoustic impedance of the polyimides is approximately 3 Mrayl.

Next, the non-conductive acoustic matching layer110and the conductive acoustic matching layer111of the present embodiment are described with reference toFIG. 2andFIG. 3.FIG. 2is a schematic perspective view showing the layered body of the acoustic matching layer (111,110) and the piezoelectrics114related to Embodiment 1.FIG. 3Ais a schematic perspective view showing a first groove110a, a second groove110b, and the conductive, films110cin the non-conductive acoustic matching layer110related to Embodiment 1.FIG. 3Bis a schematic perspective view showing the resin110dfilling each of the first grooves110aand the second grooves110bofFIG. 3A.

The non-conductive acoustic matching layer110and the conductive acoustic matching layer111adjust the acoustic impedance between the piezoelectrics114and the subject. Therefore, the non-conducting acoustic matching layer110and the conductive acoustic matching layer111are arranged between the piezoelectrics114and the front substrate122(refer toFIG. 1). Moreover, a material with different acoustic impedance is respectively used in the non-conductive acoustic matching layer110and the conductive acoustic matching layer111. This is performed in order to gradually change the acoustic impedance between the piezoelectrics114and the acoustic lens, and to achieve acoustic matching thereby. Moreover, a material allowing for the machining of metals is used in the non-conductive acoustic matching layer110.

As the non-conductive acoustic matching layer110, for example, machinable glass, machinable ceramics, a mixture of an epoxy and metal oxide powder, a mixture of epoxy and metal powder, etc., may be used. These allow for the machining of metals and have an acoustic impedance suitable for joining with the piezoelectrics114. The acoustic impedance of the non-conductive acoustic matching layer110is approximately 9 to 15 Mrayl. Moreover, carbon (isotropic graphite and/or graphite) is an example of the material of the conductive acoustic matching layer111. Carbon has an acoustic impedance suitable for arrangement between the non-conductive acoustic matching layer110and the front substrate122. The acoustic impedance of the conductive acoustic matching layer111is approximately 4 to 7 Mrayl. Moreover, although the thickness of the conductive acoustic matching layer111(length of the front-back direction (z direction inFIG. 1)) depends on the frequency band used, the frequency band generally used for the abdomen is for example 150 μm to 200 μm.

As shown inFIG. 2andFIG. 3A, the first grooves110aare provided in a boundary surface between the front surface electrodes112of the non-conductive acoustic matching layer110. Depth of the first grooves110areach the mid-way point of the non-conductive acoustic matching layer110. Here, the boundary surface is the back surface of the non-conductive acoustic matching layer110. Moreover, the mid-way point is the position between the back surface and the front surface of the non-conductive acoustic matching layer110. In other words, the first grooves110aare provided leading up to the mid-way point of the non-conductive acoustic matching layer110without penetrating the non-conductive acoustic matching layer110. Moreover, the mid-way point is not necessarily equally distant from both the back surface and the front surface.

Moreover, the second grooves110bare provided on the boundary surface with the conductive acoustic matching layer111of the non-conductive acoustic matching layer110. The second grooves110breach the mid-way point (medial part) of the non-conductive acoustic matching layer110, exceeding the edge of the front side of the first grooves110a. The boundary surface is the front surface of the non-conductive acoustic matching layer110. In other words, the second grooves110bare provided leading further backwards than the front edge of the first grooves110ain between the back surface and the front surface of the non-conductive acoustic matching layer110. In other words, the second grooves110bdo not penetrate the non-conductive acoustic matching layer110. Moreover, in an example of the depth of the first grooves110aand the second grooves110bof the non-conductive acoustic matching layer110of the present configuration, the length combining the depth of the first grooves110aand the depth of the second grooves110bis the thickness of the non-conductive acoustic matching layer110or more. Furthermore, the thickness of the non-conductive acoustic matching layer110bis the length of the non-conductive acoustic matching layer110from the back surface to the front surface or more.

Moreover, as shown inFIG. 3A, the first grooves110aare provided such that they reach from the side surface of the non-conductive acoustic matching layer110to the side surface of the opposite side. When described according toFIG. 3A, the first grooves110aare provided by penetrating in the y direction of the non-conductive acoustic matching layer110array. Moreover, the second grooves110bare provided such that they reach from the side surface without the first grooves110aexposed to the side surface of the opposite side thereof in the non-conductive acoustic matching layer110. When described according toFIG. 3A, the second grooves110bare provided while penetrating in the x direction of the non-conductive acoustic matching layer110, intersecting with the first grooves110a. That is, as shown inFIG. 1, the first grooves110aare provided by arranging in one direction in an element sequence direction with respect to each element comprising the non-conductive acoustic matching layer110arranged in a matrix state. Moreover, the second grooves110bcorresponding to this are provided by lining in a direction orthogonally intersecting the first grooves110awith respect to each element.

Moreover, the one direction of the element array in which the first grooves110aare arranged may be simply referred to as the “x direction” (refer toFIG. 1) in the following. The x direction in the element array corresponds to an example of “a first direction” in the following. Moreover, the direction in which the second grooves110bare arranged, that is, the direction orthogonally intersecting the x direction, may be simply referred to as “y direction” (refer toFIG. 1) in the following.

Furthermore, the second grooves110blead up to the mid-way point of the non-conductive acoustic matching layer110exceeding the edge of the front side of the first grooves110afrom the front surface of the non-conductive acoustic matching layer110. According to such a configuration, the first grooves110aand the second grooves110bintersect in the mid-way point of the non-conductive acoustic matching layer110. As a result, a through hole110e(refer toFIG. 6andFIG. 7) is formed via the crossing part (intersection) of the first grooves110aand the second grooves110b(refer to symbol110fofFIG. 7toFIG. 9). The through hole110epenetrates from the front surface to the back surface of the non-conductive acoustic matching layer110. Moreover, the element array direction is a direction substantially perpendicular to the irradiation direction of ultrasonic waves of the ultrasonic transducer100(front-back direction (z direction ofFIG. 1)). Moreover, the substantially orthogonal directions mentioned here are the x direction and y direction inFIG. 1(refer toFIG. 1). Moreover, it is effective to provide the second grooves110bshallower compared to the first grooves110a. Moreover, when adopting a subdie, it is effective to adjust the position of the first grooves110ato the subdie.

Furthermore, according to such a configuration, when providing a non-conductive acoustic matching layer110on the non-conductive acoustic matching layer110, the first grooves110amay be provided on each element belonging to one row in the element array with a single procedure (refer toFIG. 4,FIG. 5, andFIG. 7). In the same manner, according to the configuration of the second grooves110b, the second grooves110bmay be provided on each element belonging to one row in the element array by a single procedure. Moreover, the grooves should be provided at once to each element (layered body) belonging to one row or one column, with other configurations possible. For example, the element located on both sides of the element array direction does not necessarily need to penetrate in the element array direction.

Moreover, on the inner surfaces of the first grooves110aand the second grooves110bin the non-conductive acoustic matching layer110shown inFIG. 3(A), a conductive film110cis provided throughout the entire surface thereof by plating, spattering, etc. The first grooves110aare provided with the conductive film110cup to the mid-way point of the non-conductive acoustic matching layer110from the back surface of the non-conductive acoustic matching layer110via a crossing part110f. In other words, the conductive film110cof the first grooves110abecomes an electrical conductive path between the back surface of the non-conductive acoustic matching layer110and the crossing part110f. Moreover, the conductive film110cof the second grooves110bbecomes the electrical conductive path between the crossing part110fand front surface of the non-conductive acoustic matching layer110. Accordingly, the electrically conductive path via the through hole110eis provided between the back surface of the non-conductive acoustic matching layer110and the back surface of the conductive acoustic matching layer111. As a result, the front surface electrode112adjacent to the back surface of the non-conductive acoustic matching layer110is conducted with the wiring pattern of the front substrate122via the conductive film110cprovided in the through hole110eand the conductive acoustic matching layer111. Furthermore, the wiring pattern of the front substrate122comprises cases of electrode-plane.

Moreover, as shown inFIG. 3B, a resin110dis filled further inside the first grooves110ain the non-conductive acoustic matching layer110and the conductive film of the second grooves110bin the conductive film110c. An epoxy adhesive, etc., may be used as the resin110d. By means of filling the first grooves110aand the second grooves110bwith the resin110d, effects from providing the first grooves110aand the second grooves110bon the non-conductive acoustic matching layer110may be suppressed. However, the configuration is not necessarily limited to the configuration of filling the resin110din the first grooves110aand the second grooves110b. That is, sometimes, the resin110ddoes not need to be provided. For example, depending on the shape of the element (layered body) and/or the relationship with the vibration mode of the ultrasonic transducer100, acoustic effects caused due to providing the first grooves110aand the second grooves110bin the acoustic matching layer are sometimes small. In such cases, the resin110ddoes not need to be provided. Moreover, the resin may be provided in only one among the first grooves110aand the second grooves110b.

Moreover, the first grooves110aand the second grooves110bshown inFIGS. 1 to 3Bare provided such that the depth direction thereof is parallel to the irradiation direction of the ultrasonic waves in the ultrasonic transducer100(front-back direction of the element (z direction ofFIG. 1)). However, it is not necessarily limited to the configuration. For example, one or both of the first grooves110aand the second grooves110bmay be provided by slanting towards the front-back direction of the element. Moreover, a case was described in which the conductive film110cis provided throughout the entire inner surface of the first grooves110aand the second grooves110b; however, it is not necessarily limited to this case. The front surface electrode112and the conductive acoustic matching layer111may be conducted via the non-conductive acoustic matching layer110according to other configurations. For example, the conductive film110cmay be provided so as to pass from the edge of the back surface side of the non-conductive acoustic matching layer110to an area leading to the conductive acoustic matching layer111. Moreover, not limited to the conductive film110c, if a connecting lead may be provided to the through hole110e, such a configuration of this kind may also be adopted.

Moreover, in the non-conductive acoustic matching layer110shown inFIG. 1, the first grooves110aare arranged in the y direction alongside the x direction. Moreover, the second grooves110bare provided in the x direction alongside the y direction. However, the configuration of the ultrasonic transducer100of the present embodiment is not limited to this. That is, the first grooves110amay be provided in the x direction alongside the y direction, and the second grooves110bmay be provided in the y direction alongside the x direction.

Moreover, in the non-conductive acoustic matching layers110shown inFIG. 1toFIG. 3B, one each of the first grooves110aand the second grooves110bare respectively provided in one element. However, it is not necessarily limited to this. For example, if at least one among the first grooves110aand the second grooves110bmay be provided in plurality in one element, a configuration of this kind may also be adopted. Moreover, in the ultrasonic transducer100inFIG. 1, the piezoelectrics114, non-conductive acoustic matching layer110, conductive acoustic matching layer111, front substrate122, and the acoustic lens are arranged and layered in order from the rear to the front. However, without limiting to such a configuration, the acoustic matching layer may be three layers or more. For example, the non-conductive acoustic matching layer110, conductive acoustic matching layer111, and front substrate122may be arranged in order from the rear to the front, and furthermore, from the viewpoint of acoustic adjustment with the acoustic lens, the acoustic matching layer may be arranged on the front of the front substrate122.

Moreover, by means of suppressing the groove widths of both the first grooves110aand the second grooves110bto a maximum of approximately 30% of the element width, the radiation performance of the ultrasonic pulse, the vibration mode of the ultrasonic transducer100, the operation of providing a conductive film110c, etc. become effective. If the element is, for example, 150 μm wide, it is approximately 50 μm to 10 μm. Here, “element” is the layered body of the piezoelectrics114, non-conductive acoustic matching layer110, and conductive acoustic matching layer111(refer toFIG. 2). Moreover, “element width” is the width of the element in the array direction of the first grooves110aand the array direction of the second grooves110bof the ultrasonic transducer100(for example, x direction or y direction ofFIG. 1). Moreover, although the illustrated element has a substantially square-formed cross-section, not limited to this, the cross-section may be substantially rectangular.

The acoustic lens (not illustrated) converges the transmitted and received ultrasonic waves and forms them into a beam shape. However, in the case of a 2D-array, focus may be three-dimensionally connected by the phase control of each element; therefore, a lens function is sometimes not added. As raw materials of the acoustic lens, silicone, etc., which comprises similar acoustic impedance with the living body, is used.

(Abstract of the Manufacturing Method of the Ultrasonic Transducer)

Next, the manufacturing method of the ultrasonic transducer100related to Embodiment 1 is described with reference toFIGS. 4 to 12. Specifically, the process of providing the first grooves110aand the second grooves110bin the non-conductive acoustic matching layer110is mainly described.FIG. 4,FIG. 5, andFIGS. 10 to 12are schematic perspective views showing the manufacturing process of the ultrasonic transducer100related to Embodiment 1.

As illustrated inFIGS. 1 to 3, the acoustic matching layer in the ultrasonic transducer100of the present embodiment is configured by layering the non-conductive acoustic matching layer110and the conductive acoustic matching layer111. A non-conductive material block1101shown inFIG. 4is used in forming the non-conductive acoustic matching layer110of the acoustic matching layer. In the same manner, a conductive material block1111is used in manufacturing the conductive acoustic matching layer (FIG. 10)111. Moreover, the non-conductive material block1101and the conductive material block1111are as shown inFIG. 12after they have been divided so that they may be two-dimensionally arrayed.

First, as shown inFIG. 4, with respect to the non-conductive material block1101, the first grooves110aare formed with a desired pitch in the y direction alongside the x direction (y direction inFIG. 1). The first grooves110aare provided leading to the mid-way point of the non-conductive material block1101from the back surface of the non-conductive material block1101. That is, it is provided up to the mid-way point between the back surface and the front surface of the non-conductive material block1101so as to prevent from penetrating the non-conductive material block1101in the front-back direction (depth).

Moreover, the first grooves110aare provided in pluralities with a pitch corresponding to the element pitch of the ultrasonic transducer100. In other words, when providing the first grooves110aalongside the x direction of the element array, at least the number of first grooves110acorresponding to the number of rows are provided. Moreover, when providing the first grooves110aalongside the y direction of the element array, at least the number of first grooves110acorresponding to the number of columns is provided. Moreover, the number of first grooves110ain the acoustic matching layer block1101inFIG. 4, etc., is shown as a concept.

As mentioned above, for the first grooves110a, cutting is provided in the non-conductive acoustic matching layer110. The cutting width (width of the first grooves110a) may be, for example, approximately 30% or less of the element width and 10 μm or more. As an example of the cut-in width to the element width under such circumstances, having a width of 50 μm for the element width of 350 μm may be considered. Moreover, the pitch of the cut-in width may be approximately 0.4 mm. Such a cut-in width is effective for the radiation performance of the ultrasonic pulse, the vibration mode of the ultrasonic transducer100, and the formation process of the conductive film110c.

<<Forming of the Second Groove/FIG. 5>>

As shown inFIG. 4, the second grooves110bare provided along with or simultaneously with providing the first grooves110ato the non-conductive material block1101(FIG. 5). The second grooves110bare provided backwards from the front surface of the non-conductive material block1101, to a location exceeding the edge of the front side of the first grooves110a. Thereby, the second grooves110blead up to the mid-way point of the non-conductive acoustic matching layer110. That is, it is provided such that the non-conductive acoustic matching layer110is not penetrated in the front-back direction. For example, it is provided in a position leading further backwards than the crossing part110flocated between the back surface and the front surface of the non-conductive acoustic matching layer110(refer toFIG. 8,FIG. 9).

Moreover, the second grooves110bare provided in pluralities with a pitch corresponding to the element pitch of the ultrasonic transducer100. In other words, when providing the second grooves110balongside the x direction of the element array, at least the number second grooves110bcorresponding to the number of rows are provided. Moreover, when providing the second grooves110balongside the y direction of the element array, at least the number of second grooves110bcorresponding to the number of columns are provided.

Here, the crossing part110fof the first grooves110aand the second grooves110bformed in the non-conductive material block1101as well as the through hole110eare described with reference toFIGS. 6 to 9.FIG. 6is a schematic perspective view showing the first grooves110a, the second grooves110b, and the through hole110eof the non-conductive material block1101ofFIG. 5.FIG. 7is the schematic perspective view showing the inner configuration of the non-conductive material block1101ofFIG. 6.FIG. 8is the A-A cross-section view of the non-conductive material block1101shown inFIG. 7.FIG. 9is the B-B cross-section view of the non-conductive material block1101shown inFIG. 7.

When the first grooves110aand the second grooves110bare formed, as shown inFIG. 6andFIG. 7, the first grooves110aand the second grooves110bintersect each other. Moreover, due to the first grooves110aand the second grooves110bintersecting each other, the through hole110ethat passes from the front surface to the back surface of the non-conductive material block1101is formed. As shown inFIG. 8, in the cross-section along the second grooves110bin the non-conductive material block1101(A-A cross-section ofFIG. 7), the first grooves110aare arranged with a predetermined pitch. Furthermore, as shown inFIG. 9, in the cross-section of the non-conductive material block1101orthogonally intersecting the cross-section ofFIG. 8(B-B cross-section ofFIG. 7), the second grooves110bare arranged with a predetermined pitch. The base of the first grooves110aand second grooves110bare connected in the area in which the first grooves110aand the second grooves110bintersect (crossing part110fofFIG. 8,FIG. 9). Furthermore, as shown inFIG. 6andFIG. 7, the crossing part110fis formed in correspondence with the element pitch in the y direction and x direction.

In the subsequent process, the non-conductive material block1101is connected to the conductive material block1111and the piezoelectrics material block1141(FIG. 10.FIG. 11), thus forming the layered bodies. As mentioned above, by means of forming the first grooves110aand the second grooves110bwith the predetermined pitch, each non-conductive acoustic matching layer110is provided with at least one or more through holes110ewhen the layered bodies are divided in the xy direction (FIG. 12).

In providing the second grooves110b, the cutting width (width of the second grooves110b) may be approximately 30% or less of the element width and 10 μm or more in terms of the radiation performance of the ultrasonic pulse, the vibration mode of the ultrasonic transducer100, and the formation process of the conductive film110c. Moreover, regarding the order of providing the first grooves110aand the second grooves110b, either may come first or they may be simultaneous. Moreover, the number of the second grooves110bin the non-conductive material block1101inFIG. 5, etc., is shown as a concept.

Next, the conductive film110cis provided on the first grooves110aand the second grooves110b. The conductive film110cis, for example, provided throughout the entire inner surface of the first grooves110aand the second grooves110bby plating, spattering, etc. At this time, the conductive film may also be provided on the front surface, back surface, side surface, etc., of the non-conductive material block. Thereby, the first grooves110aand the second grooves110b(through hole110e) are electrically conducted from one end to the other. Moreover, one end to the other indicates from the back surface to the front surface of the non-conductive material block is indicated. Furthermore, the front surface electrode112adjacent to the back surface of the non-conductive acoustic matching layer110is electrically conducted with the wiring pattern of the front substrate122via the conductive film110cand the conductive acoustic matching layer111.

Moreover, the conductive film110cdoes not necessarily have to be provided on the entire inner surface of the second grooves110band the front surface, back surface, and side surface of the non-conductive material block. For example, it may be a part of the side surface among the inner surfaces of the first grooves110aand the second grooves110b. That is, if the conductive film110cmay be provided such that it passes from one end of the first grooves110a(edge of the back surface side) to the other end of the second grooves110b(conductive acoustic matching layer111side), it does not need to be provided on the entire inner surface of the first grooves110aand the second grooves110b. That is, if an electrical connection may be ensured without fail from the front surface electrode112to the conductive acoustic matching layer111, the conductive film110cmay be provided only on a part of the side surface leading from one end to the other end of the through hole110e. Moreover, if the connecting lead may be provided from the front surface electrode112to the conductive acoustic matching layer111by passing the first grooves110aand the second grooves110b, the connecting lead may be provided instead of the conductive film110c.

After providing the conductive film110c, a process may be conducted whereby the resin110dis filled further inside the conductive film110con each of the first grooves110aand the second grooves110b. Whether or not to conduct this procedure is determined by the vibration design of the element. An epoxy adhesive, etc., may be used for the resin110d; however, sometimes a silicone-based rubber adhesive is used. However, depending on the shape of the element and the vibration mode of the ultrasonic transducer100, sometimes there is little acoustic effect due to the first grooves110aand the second grooves110b; in such cases, a resin110ddoes not need to be provided. Furthermore, the element indicates the layered bodies of the piezoelectrics114, non-conductive acoustic matching layer110, and conductive acoustic matching layer111. Moreover, the resin110dmay be provided on only one among the first grooves110aand the second grooves110b.

Moreover, regarding the order of providing the conductive film110cand the resin110d, this does not necessarily need to be conducted after providing both the first grooves110aand the second grooves110b. For example, after the first grooves110aare provided, the conductive film110cand the resin110dare first provided from the first grooves110aside before providing the second grooves110b. The conductive film110cand resin110dmay be subsequently provided in the second grooves110b. However, the process mentioned above of simultaneously providing the conductive film110cand the resin110dafter providing both the first grooves110aand the second grooves110bis easier as the manufacturing process of the ultrasonic transducer100.

After the conductive film110cis provided on the non-conductive material block1101, or after the resin110dis provided when there is a resin110d, the non-conductive material block1101and the conductive material block1111are connected. That is, as shown inFIG. 10andFIG. 11, the conductive material blocks1111are layered on the surface in which the edges of the second grooves110bin the non-conductive material block1101are exposed, and then connected. Moreover, in the subsequent process, split grooves are provided in the xy direction to both the non-conductive material block1101and the conductive material block1111, and thereby the number of layered bodies corresponding to the number of desired elements is formed, as shown inFIG. 12.

After layering the non-conductive material block1101and the conductive material block1111, the acoustic matching layer block thereof and a piezoelectrics material block1141are connected. That is, as shown inFIG. 10andFIG. 11, the piezoelectrics material block1141is connected to the surface opposite to connection surface of the conductive material block1111in the non-conductive material block1101. Furthermore, it is determined that the layer to become the front surface electrode112be provided in advance on the front surface of the piezoelectrics material block1141. In the same manner, it is determined that the layer to become the back surface electrode116be provided in advance on the back surface of the piezoelectrics material block1141. Moreover, the split grooves are provided in the piezoelectrics material block1141in the xy direction during the subsequent process, and are divided so that the desired number of elements of the piezoelectrics114in the ultrasonic transducer100is achieved (refer toFIG. 1). Furthermore, regarding the order of connecting the conductive material block1111and the piezoelectrics material block1141to the non-conductive material block1101, either may come first.

The rear substrate120is connected to the back surface of the back surface electrode116in the piezoelectrics114. Thereby, the wiring pattern of the front substrate122is electrically conducted with each conductive acoustic matching layer111. The wiring pattern may be the electrode-plane as a ground. Moreover, the wiring pattern of the rear substrate120and the back surface electrode116are electrically connected.

Next, the split grooves are provided in the xy direction to the layered bodies of the non-conductive material block1101, conductive material block1111, and piezoelectrics material block1141. That is, as shown inFIG. 12, the split grooves are formed in a predetermined pitch in columns in the y direction along to the lamination direction of the acoustic matching layer block and the piezoelectric material block1141, splitting the layered body of the block into blocks with a plurality of columns. Furthermore, the split grooves are provided in a predetermined pitch in rows in the x direction along the lamination direction of the acoustic matching layer block and the piezoelectric material block1141. As a result, the element group is formed, the element group configuring a two-dimensional array of the layered body of the piezoelectrics114, non-conductive acoustic matching layer110, and conductive acoustic matching layer111as shown inFIG. 12(the rear substrate120, however, which is already connected and adhered, is not illustrated).

After the elements are divided and the two-dimensional array is formed, a backing material118is connected to the back surface of the rear substrate120. Moreover, regarding the configuration between the piezoelectrics114, rear substrate120, and backing material118, without limitation to those shown inFIG. 1, structures such as an electrical circuit that process signals as necessary, a back surface matching layer, etc., may be interpositioned. However, the present backing adhering process may be conducted before the process of forming the split element grooves.

The front substrate122is connected on the front surface of the conductive acoustic matching layer111separated in the two-dimensional array. Thereby, the wiring pattern of the front substrate122and respective conductive acoustic matching layers111are electrically connected. The wiring pattern may be the electrode-plane as a ground.

<<Adding an Acoustic Matching Layer>>

If necessary, upon performance design, the acoustic matching layer may be further formed in front of the front circuit substrate122.

After forming the configurations necessary upon design such as connecting the substrate to the front surface and back surface of the element group of the two-dimensional array, forming the additional acoustic matching layer, etc., the acoustic lens is formed or adhered to the very front surface of an oscillator as the final process. Furthermore, as mentioned above, when configuring the acoustic matching layer with three layers or more, the acoustic matching layer is arranged on the front surface of the front substrate122without adjoining the front substrate122and the acoustic lens. In this case, the acoustic lens is arranged on the further front surface of the acoustic matching layer located at the very front.

(Connection of the Ultrasonic Transducer and the External Device)

Next, an example of a connection configuration between the ultrasonic probe comprising the ultrasonic transducer100of Embodiment 1 and the ultrasonic diagnostic equipment body is described. Moreover, illustrations are omitted in the following description. The ultrasonic transducer100is provided inside the ultrasonic probe, comprising an interface (cable, etc.) in order to electrically connect the ultrasonic diagnostic equipment body and the ultrasonic probe. Moreover, the ultrasonic transducer100is electrically connected to the ultrasonic diagnostic equipment via a wiring pattern of the front substrate122(including a case of electrode-plane) and the interface of the rear substrate120, and the interface of. The signals related to the transmitting and receiving of ultrasonic waves are alternately transmitted by the wiring pattern and interface.

Moreover, the circuit board provided with the electrical circuit such as the transmitter-receiver circuit, etc., may be provided inside the ultrasonic probe. Moreover, the connecting substrate connecting the interface and the electrical circuit may be provided inside the ultrasonic probe. In this case, the connecting substrate becomes the path through which transmitted and received, the interface connecting the ultrasonic probe and the body, the wiring pattern of the connecting substrate, and the circuit substrate are transmitted and received control unit of the ultrasonic diagnostic equipment body.

For example, the control unit of the ultrasonic diagnostic equipment body transmits electrical signals using the control of the drive of the ultrasonic transducer100to the ultrasonic probe via the interface. The electrical signals are transmitted to the electric circuit of the circuit board via the connecting substrate. The electric circuit applies voltage to the piezoelectrics114via the front substrate122and the rear substrate120based on signals from the control unit of the ultrasonic diagnostic equipment body. For example, voltage is applied to the back surface electrode116via the rear substrate120. The front surface electrode112is connected to the ground via the first grooves110a, the second grooves110b, and the conductive acoustic matching layer111of the non-conductive acoustic matching layer110as well as the wiring pattern of the front substrate122. Voltage is applied to the piezoelectrics114in this manner and ultrasonic pulses are transmitted to the test object.

Moreover, for example, when the ultrasonic transducer100receives reflected waves from the test object, the ultrasonic diagnostic equipment body transmits the electric signals converted by the piezoelectrics114to the electric circuit via the rear substrate120, etc. Depending on the configuration, the electric signals converted by the piezoelectrics114are transmitted to the electric circuit via the non-conductive acoustic matching layer110, conductive acoustic matching layer111, front substrate122, etc. The electric circuit performs predetermined processing (adding delays (phasing addition), amplifying, etc.) to the electric signals and furthermore, transmits the electric signals to the ultrasonic diagnostic equipment body via the connecting substrate and the interface. Based on the electric signals, ultrasonic images are produced on the ultrasonic diagnostic equipment body side.

The function and effect of the ultrasonic transducer100and the ultrasonic probe related to Embodiment 1 described above are described.

As described above, in the ultrasonic transducer100of Embodiment 1, in the boundary surface (back surface of the non-conductive acoustic matching layer110) between the front surface electrode112and the ultrasonic transducer100in each non-conductive acoustic matching layer110, the first grooves110ahaving depth leading up to the mid-way point are provided. Furthermore, in the non-conductive acoustic matching layer110, the second grooves110bhaving depth leading up to the mid-way point of the non-conductive acoustic matching layer110are provided on the boundary surface (front surface of the non-conductive acoustic matching layer110) between the conductive acoustic matching layer111and the conductive acoustic matching layer110. The mid-way point is, as mentioned above, a location further backwards than the front edge of the first grooves110a. Moreover, the crossing part110fis formed by the first grooves110aand the second grooves110b. As a result, as shown inFIG. 6andFIG. 7, the through hole110eleading from the boundary surface with the front surface electrode112to the boundary surface with the conductive acoustic matching layer111is formed. Furthermore, the conductive film110cis provided so as to pass from at least the edge of the back surface side to the edge of the front surface of the non-conductive acoustic matching layer110(area leading to the back surface of the conductive acoustic matching layer111) in the inner surface of the first grooves110aand the second grooves110b. In other words, the conductive film110cis provided so as to pass from the rear edge of the first grooves110ato the front edge of the second grooves110b.

Consequently, by means of providing the first grooves110aand the second grooves110bin the non-conductive material block1101, the conductive path may be formed on the non-conductive acoustic matching layer110by the process of forming the through hole110eand the process of providing the conductive film110con the through hole110ealone. Furthermore, the non-conductive material block1101, conductive material block1111, and piezoelectrics material block1141are layered in order to form the layered body. Subsequently, the split grooves are provided in the xy direction for the layered body, thereby forming the two-dimensional array of the element configured by comprising the layered body of the piezoelectrics114, non-conductive acoustic matching layer110, and conductive acoustic matching layer111.

According to the ultrasonic transducer100manufactured by the manufacturing process, forming the conductive path of the non-conductive acoustic matching layer110may be made easier. Consequently, complication of the manufacturing process of the ultrasonic transducer100may be avoided. That is, the manufacturing process is simple if a configuration is achieved by providing the first grooves110a, the second grooves110b, and conductive film110cin the non-conductive acoustic matching layer110, and furthermore, the conductive path may be provided without fail from the front surface electrode112to the conductive acoustic matching layer111.

Next, the ultrasonic probe related to Embodiment 2 and the ultrasonic probe provided with the ultrasonic transducer are described with reference toFIGS. 13 to 17.FIG. 13is a schematic perspective view showing the abstract of a non-conductive material block2101of the ultrasonic transducer related to Embodiment 2. Furthermore, areas differing from Embodiment 1 are mainly described in Embodiment 2, descriptions of other overlapping areas sometimes omitted. Moreover, the number of first grooves210aand second grooves210bin the non-conductive material block2101shown inFIG. 13are shown as a concept.

(Schematic Configuration of the Ultrasonic Transducer)

In the ultrasonic transducer related to Embodiment 2 as well, the piezoelectrics are two-dimensionally arranged on the xy surface. The front surface electrode is arranged on each of the front surface side of the piezoelectrics, while the back surface electrode is provided on each of the back surface side of the piezoelectrics. Moreover, the non-conductive acoustic matching layer210(refer toFIG. 14,FIG. 16, etc.) is provided in correspondence with each front surface of the respective piezoelectrics. Furthermore, the conductive acoustic matching layer, front substrate, and acoustic lens are provided in order towards the front surface in front of the non-conductive acoustic matching layer210. Moreover, the backing material is provided on the back side of the piezoelectrics. The rear substrate is provided between the backing material and the piezoelectrics.

(Configuration of the Non-conducting Acoustic Matching Layer and the Second Groove)

Next, the non-conductive acoustic matching layer210, the first grooves210a, and the second grooves210bin the ultrasonic transducer of Embodiment 2 are described with reference toFIGS. 13 to 17.FIG. 14is a top schematic perspective view of the non-conductive acoustic matching layer210related to Embodiment 2, and shows an abstract of an example of the second grooves210bprovided in the non-conductive acoustic matching layer210. A non-conductive acoustic matching layer group230in the figure shows the entire two-dimensional array element arrangement of the non-conductive acoustic matching layer210in the figure as one conceptual bundle with dashed lines as a concept. Moreover, the crossing part220is the area in which the first grooves210aparallel to the element array (x direction in the figure) and the second grooves210brunning diagonally towards the element array intersect. That is, the crossing part220shows the through hole formed in the non-conductive acoustic matching layer210. Furthermore, inFIG. 14, among the plurality of two-dimensionally arranged non-conductive acoustic matching layers210, only a part of the non-conductive acoustic matching layer210is shown.FIG. 15is the schematic enlarged view of a part ofFIG. 14.

In Embodiment 2 as well, the conductive path electrically connecting from the front surface electrode to the conductive acoustic matching layer are formed by the first grooves210aand the second grooves210b(refer toFIG. 13) in the same manner as Embodiment 1. The first grooves210aare provided in the back surface of the non-conductive acoustic matching layer210, the first grooves210ahaving depth leading up to the mid-way point. Moreover, the second grooves210bare provided in the front surface of the non-conductive acoustic matching layer210. The second grooves210blead up to the mid-way point. The mid-way point indicates the location further backwards than the front edge of the first grooves210a. The crossing part220of the first grooves210aand the second grooves210bbeing formed, as a result, the through hole leading from the boundary surface with the front surface electrode of the piezoelectrics in the non-conductive acoustic matching layer210to the boundary surface with the conductive acoustic matching layer is formed.

[Groove Direction (Angle of the Groove)]

Moreover, in the same manner as Embodiment 1, the first grooves210aof Embodiment 2 are provided in the y direction by penetrating towards the x direction with respect to the non-conductive acoustic matching layer210arranged in a matrix state. That is, the first grooves210aare formed by penetrating in the x direction of the array of the non-conductive acoustic matching layer210so as to lead from the side surface of the non-conductive acoustic matching layer210to the side surface of the opposite side.

Whereas, the second grooves210bof Embodiment 2 are, as shown inFIG. 14, provided such that they are slanted towards the array direction of the non-conductive acoustic matching layer210(for example, x direction) by a predetermined angle. Moreover, the second grooves210bare provided so as to intersect the first grooves210a. The inclination angle of the second grooves210bis set to, for example, less than 90°. The inclination angle is the angle at which the second grooves210bare slanted in the x direction in the two-dimensionally arranged non-conductive acoustic matching layer210. The angle is established in order to provide the second grooves210bso as to intersect the first grooves210a. Furthermore, the inclination angle is the smaller angle among the angles configured by the array direction (for example, x direction) and the second grooves210b(for example, θ inFIG. 14).

When the inclination angle of the second grooves210bis 0°, sometimes the second grooves210band the first grooves210abecome parallel. When the second grooves210band the first grooves210abecome parallel, sometimes the non-conductive acoustic matching layer210is separated in small strips. Consequently, the angle configured by the groove210aand the groove210bis preferably approximately 30° to 90°.

Moreover, the second grooves210bare formed by penetrating from one end to the other of the non-conductive acoustic matching layer210.

In Embodiment 2 as well, the first grooves210amay be provided by a single process to the non-conductive acoustic matching layer with respect to each element belonging to one column in the element array (refer toFIG. 13). In the same manner, the second grooves210bmay also be provided by a single process with respect to each of the plurality of elements in the element array. Moreover, the elements are arranged in a direction substantially perpendicular to the front-back direction of the ultrasonic transducer (refer to the z direction ofFIG. 1). Moreover, the grooves should be provided at once to each of the plurality of elements, though other configurations are possible. For example, the element located on both sides of the element array direction (layered body) does not necessarily need to penetrate in the element array direction.

The second grooves210bof Embodiment 2 are provided by slanting for the element array. Next, examples of the pitch between the second grooves210b(a groove pitch) are described with reference toFIGS. 14 to 17. Moreover, the pitch between the second grooves210b, that is, the groove pitch, indicates the distance from the halfway line of one of the second grooves210bto the halfway line of the adjacent second groove210b(refer toFIG. 15). That is, this shows the distance from the center of one of the second grooves210bto the center of the adjacent second groove210b. Moreover, for convenience of explanation, the groove pitch of the second grooves210bmay simply be referred to as “Pk2”, “Pk4”, “Pk6”, or “Pk8” in the following explanation. Moreover, for convenience of explanation, the groove pitch of the first grooves210amay simply be referred to as “Pk1”, “Pk3”, “Pk5”, or “Pk7”. Moreover, for convenience of explanation, the pitch of the through hole formed in the crossing part220of the first grooves210aand the second grooves210bmay be referred to as “Ph.” The Ph is, for example, the pitch of the through hole in the x direction inFIG. 15.

Moreover, the element width in one of the non-conductive acoustic matching layers210may simply be referred to as “Pw”. That is, PW is the length in the array direction of the non-conductive acoustic matching layer210(for example, x direction inFIG. 15). In other words, Pw is the length from one side surface of the non-conductive acoustic matching layer210to the side surface of the opposite side. In the example ofFIG. 15, “Pw” is the element width in the x direction.

Moreover,FIG. 15shows the arrangement of the non-conductive acoustic matching layer210corresponding with a piezoelectric element sequence in the matrix state. For example, the periodic distance from the left edge of the non-conductive acoustic matching layer210in the x direction ofFIG. 15to the left edge of the adjacent element may simply be referred to as “Pe”. In other words, Pe is the length from the center of the width distance of one of the non-conductive acoustic matching layers210to the center of the adjacent non-conductive acoustic matching layer210(element pitch). That is, Pe is the length that combines an element interval of the non-conductive acoustic matching layer210and the element width Pw. Moreover, the element interval mentioned here refers to the length from the right edge of the width direction of one of the non-conductive acoustic matching layers210to the left edge widthwise of the adjacent on-conductive acoustic matching layer210.

Moreover, among the inclining angles of the second grooves210b, the smaller angle may simply be referred to as “θ” Here, the inclining angle refers to the angle configured by the array direction of the element (for example, x direction) and the second grooves210b.

The groove pitch Pk6of the second grooves210bof Embodiment 2 may be set as the element width Pw or less, as shown inFIG. 15.

The groove pitch Pk2of the second grooves210bof Embodiment 2 may be set as equal to or less than the element width Pw; furthermore, as illustrated inFIG. 15, the relationship between Pk and Pw may be established using the formula (1) below.

Regarding each of the non-conductive acoustic matching layers210, at least one or more through holes must be established as the conductive path in the front-back direction of the ultrasonic transducer (refer to the z direction ofFIG. 1). According to the “groove pitch example 1” mentioned above, the through hole may be formed without particular hindrance even if the second grooves210bare inclined towards the array direction x. Moreover, according to the “groove pitch example 2,” establishing the groove pitch Pk for further forming the through hole in the non-conductive acoustic matching layer210becomes easier. Moreover, by means of setting the range of the degree of “θ” to greater than 30° and less than 90° (30°<θ<90°), establishment of the groove pitch Pk becomes much easier (in the first embodiment, θ is equivalent to 90°).

Next, another example of the groove pitch Pk is described with reference toFIG. 16andFIG. 17.FIG. 16is a top schematic perspective view of the non-conductive acoustic matching layer210related to Embodiment 2, showing another example of the second grooves210bprovided in the non-conductive acoustic matching layer210. The non-conductive acoustic matching layer group230indicated by dashed lines in the figure shows the entire two-dimensional array element sequence of the non-conductive acoustic matching layer210in the figure as one conceptual bundle with dashed lines.FIG. 17is the schematic enlarged view of a part ofFIG. 16.

As illustrated inFIG. 16, the groove pitch Pk8of the second grooves210bof Embodiment 2 may be set equally with the element pitch Pe. However, this includes accidental errors during the manufacturing process.

As illustrated inFIG. 17, the groove pitch Pk4of the second grooves210bof Embodiment 2 may be set as in the following formula (2) regarding the relationship with the element pitch Pe. However, this includes accidental errors during the manufacturing process.

In the same manner as the “groove pitch example 1” mentioned above, according to the “groove pitch example 3,” even if the second grooves210bare inclined towards the array direction x, the fear of forming of the through hole being affected due to the relationship with the first grooves210amay be avoided. Moreover, in the same manner as the “groove pitch example 2,” according to the “groove pitch example 4,” establishing the groove pitch Pk for further forming of the through hole in the non-conductive acoustic matching layer210becomes easier. Moreover, by means of setting the range of the degree of “θ” to greater than 30° and less than 90° (30°<θ<90°), establishment of the groove pitch Pk becomes much easier.

[Conductive Path of the Non-conductive Acoustic Matching Layer]

Moreover, the first grooves210aand the second grooves210bin the non-conductive acoustic matching layer210, a conductive film is provided throughout the entire surface thereof by plating, spattering, etc. This point is the same as in Embodiment 1. The through hole formed by the first grooves210a, the second grooves210b, and the crossing part220thereof leads from the back surface of the non-conductive acoustic matching layer210to the front surface (back surface of the conductive acoustic matching layer111). Furthermore, in the through hole formed by the first grooves210a, the second grooves210b, and the crossing part220thereof, the conductive film210cis provided in succession from at least one end of the through hole to the other end. That is, the edge of the front surface side to the edge of the back surface side (back surface of the conductive acoustic matching layer) is electrically conducted. As a result, the front surface electrode is conducted with the conductive acoustic matching layer adjacent to the front surface of the non-conductive acoustic matching layer210via the non-conductive acoustic matching layer20. Furthermore, the front surface electrode is conducted with the wiring pattern of the front substrate via the non-conductive acoustic matching layer and the conductive acoustic matching layer.

Moreover, in Embodiment 2 as well, resin is filled further on the inner surfaces of the first grooves210ain the non-conductive acoustic matching layer210and the conductive film of the second grooves210b. Depending on the shape of the element (layered body) and/or the vibration mode of the ultrasonic transducer, the acoustic effects caused due to providing the first grooves210aand the second grooves210bin the acoustic matching layer210are sometimes small. That is, in such cases, the resin does not need to be provided. Moreover, the resin may be provided in only one among the first grooves210aand the second grooves210b.

Furthermore, another configuration may be taken as long as the front surface electrode and the conductive acoustic matching layer are conducted. For example, the conductive path may be provided to the through hole alone such that it passes from the edge of the front surface side to the edge of the back surface side of the non-conductive acoustic matching layer210among the inner surfaces of the first grooves210aand the second grooves210b. Moreover, if the connecting lead may be provided, a configuration of this kind may also be adopted. This is the same as in Embodiment 1.

Moreover, regarding the non-conductive acoustic matching layer210mentioned above, the first grooves210aare provided in parallel to the array direction, and the second grooves210bare provided so as to incline with the array direction x. However, the configuration is not limited to these as the ultrasonic transducer100of Embodiment 2. For example, the first grooves210amay incline in the array direction and the second grooves210bmay be provided in parallel with the array direction y.

When inclining the first grooves210ain the array direction in Embodiment 2 as mentioned above, the groove pitch Pk5may be established as equal to or less than the element width Pw.

When inclining the first grooves210ain the array direction in Embodiment 2, the groove pitch Pk1of the first grooves210amay be set as in the following formula (3) regarding the relationship with the element pitch Pe. However, this includes accidental errors during the manufacturing process.

As illustrated inFIG. 16, the groove pitch Pk7of the second grooves210bof Embodiment 2 may be set equally with the element pitch Pe. However, this includes accidental errors during the manufacturing process.

Moreover, when inclining the first grooves210ain the array direction in Embodiment 2, the groove pitch Pk3of the first grooves210amay be set as in the following formula (4) regarding the relationship with the element pitch Pe. However, this includes accidental errors during the manufacturing process.

Regarding each of the non-conductive acoustic matching layers210, at least one or more through holes must be established as the conductive path in the front-back direction of the ultrasonic transducer (refer to the z direction ofFIG. 1). According to the “groove pitch example 5” and the “groove pitch example 7” mentioned above, the fear of forming of the through hole being affected due to the relationship with the first grooves210amay be avoided even if the second grooves210bare inclined towards the array direction x. Moreover, according to the “groove pitch example 6” and the “groove pitch example 8,” establishing the groove pitch Pk for further forming the through hole in the non-conductive acoustic matching layer210becomes easier. Moreover, by means of setting the range of the degree of “θ” to greater than 30° and less than 90° (30°<θ<90°), establishment of the groove pitch Pk becomes much easier.

Moreover, there may be three or more acoustic matching layers and, for example, the acoustic matching layer may be provided in front of the front substrate.

Moreover, the optimal width of the first grooves210aand the second grooves210b(array direction length) is the same as in Embodiment 1, so explanations are omitted.

(Abstract of the Manufacturing Method of the Ultrasonic Transducer)

Next, with reference toFIG. 13, the manufacturing method of the ultrasonic transducer related to Embodiment 2 is described. Particularly, the procedure of providing the first grooves210aand the second grooves210bof the non-conducting acoustic matching layer210is primarily described.

<<Forming the First Grooves>>

A non-conductive material block2101is also used in making the acoustic matching layer210in the ultrasonic transducer of Embodiment 2. Regarding the method of the manufacturing process of the ultrasonic transducer of Embodiment 2, first, as shown inFIG. 13, the first grooves210aare provided with a predetermined pitch in the y direction alongside the x direction with respect to the non-conductive material block2101. Moreover, the x direction and y direction mentioned here are the element array directions after the blocks are two-dimensionally split. The first grooves210aare provided such that they reach from the back side of the non-conductive material block2101to the mid-way point of the block thickness. That is, it is provided leading up to the mid-way point between the back surface and the front surfaces in the non-conductive material block2101such that the non-conductive material block2101is not penetrated.

Moreover, in the same manner as Embodiment 1, if the first grooves210aare arranged in parallel to the x direction of the element array, at least the number corresponding to the number of rows is formed. Moreover, when arranging the first grooves210ain parallel with the y direction, at least the number corresponding to the number of columns is formed. Moreover, the number of first grooves210aof the non-conductive material block2101inFIG. 13is conceptually shown.

As an example of the cut-in width of the first grooves210a, that is, the width of the first grooves210a, it may be approximately 30% or less of the element width and 10 μm or more. Under such conditions, for example, when the element width is 350 μm, having a cut-in width of 50 μm may be considered. Moreover, the pitch of the cut-in width may be approximately 0.4 mm. If such a cut-in width may be achieved, it is effective for the radiation performance of the ultrasonic pulse, the vibration mode of the ultrasonic transducer, and the formation process of the conductive film.

Next, the second grooves210bas shown inFIG. 13are provided in the non-conductive material block2101. The second grooves210bare provided leading from the front surface to the mid-way point of the non-conductive material block2101. The mid-way point is any position in the non-conductive acoustic matching layer210that exceeds the edge of the front side of the first grooves210abackwards, leading up to the back side of the non-conductive acoustic matching layer210. That is, the second grooves210bare provided further backwards than the crossing part220of the first grooves210abetween the back surface and the front surface in the non-conductive material block2101so as not to penetrate the non-conductive material block2101.

Moreover, the second grooves210bare provided in pluralities in a predetermined pitch with respect to the non-conductive material block2101. Moreover, the second grooves210bare provided by slanting towards the array direction x (refer toFIG. 14, etc.) with respect to non-conductive material block2101at a predetermined angle. Moreover, the array direction x is the array direction of the non-conductive acoustic matching layer210when the block is two-dimensionally divided. Furthermore, the second grooves210bare provided so as to intersect with the first grooves210a. The inclination angle of the second grooves210bis set at, for example, less than 90° such that these may be provided so as to intersect the second grooves210band the first grooves210a.

Moreover, the pitch providing the second grooves210bis a pitch in which at least one or more through holes are formed in each non-conductive acoustic matching layer210as the conductive path. As concrete examples, the groove pitch examples 1 to 4, etc. are mentioned above. Moreover, the through hole is formed in the front-back direction of the ultrasonic transducer (refer to the z direction ofFIG. 1).

The cut-in width of the second grooves210bis determined based on the radiation performance of the ultrasonic pulse, the vibration mode of the ultrasonic transducer, and the formation process of the conductive film. Moreover, the cut-in width is the width of the second grooves210b, wherein, for example, it may be set at approximately 30% or less of the element width and 10 μm or more. Moreover, regarding the order of establishing the first grooves210aand the second grooves210b, either may come first.

Moreover, the processes of forming the conductive film and filling with resin, connecting the block, connecting the piezoelectrics, forming the split grooves, connecting the front substrate and the rear substrate, connecting the backing material, and connecting the acoustic lens of Embodiment 2 are the same as Embodiment 1, so explanations are omitted.

The function and effect of the ultrasonic transducer and the ultrasonic probe related to Embodiment 2 are described.

As described above, in the ultrasonic transducer of Embodiment 2, in each non-conductive acoustic matching layer210, the first grooves210aare provided reaching from the boundary surface (back surface of the non-conductive acoustic matching layer210), with the front surface electrode leading up to the mid-way point. Furthermore, the non-conductive acoustic matching layer210is provided with the second grooves210bleading from the boundary surface with the conductive acoustic matching layer211(front surface of the non-conductive acoustic matching layer210) to the mid-way point of the non-conductive acoustic matching layer210. The mid-way point is, as mentioned above, the location further backwards than the front edge of the first grooves210a. Moreover, the crossing part220is formed by the first grooves210aand second grooves210b. As a result, the through hole leading from the boundary surface with the front surface electrode to the boundary surface with the conductive acoustic matching layer is formed. Furthermore, the conductive film210cis provided passing from at least the edge of the back surface side to the edge of the front surface side (area leading up to the conductive acoustic matching layer) on the inner surfaces of the first grooves210aand the second grooves210b. In other words, the conductive film is provided passing the rear edge of first grooves210ato the front edge of the second grooves210b.

Accordingly, by means of providing the first grooves210aand the second grooves210bin the non-conductive material block2101, the conductive path may be formed on the non-conductive acoustic matching layer210by the process of forming the through hole and the process of providing the conductive path on the through hole alone. Furthermore, the non-conductive material block2101, conductive material block, and piezoelectrics material block are layered in order to form the layered body. Next, by means of providing the split cells in the xy direction with respect to the layered body, the two-dimensional array of the element is formed, configured by comprising the piezoelectrics, non-conductive acoustic matching layer210, and the layered body of the conductive acoustic matching layer.

According to the ultrasonic transducer manufactured by such a manufacturing process, forming the conductive path of the non-conductive acoustic matching layer210may be made easier. Consequently, both avoiding the complication of the manufacturing process of the ultrasonic transducer and forming the conductive path from the front surface electrode to the front substrate may be achieved. That is, the manufacturing process is simple if the configuration comprises the first grooves210a, the second grooves210b, and the conductive film in the non-conductive acoustic matching layer210, and furthermore, the conductive path may be provided without fail from the front surface electrode to the conductive acoustic matching layer.

Next, the ultrasonic transducer related to Embodiment 3 and the ultrasonic probe provided with the ultrasonic transducer are described with reference toFIG. 18.FIG. 18is the top schematic perspective view of the non-conductive acoustic matching layer of Embodiment 3, and shows the abstract of an example of the first grooves and the second grooves provided in the non-conductive acoustic matching layer of the ultrasonic transducer. The non-conductive acoustic matching layer group330indicated by dashed lines in the figure shows the entire two-dimensional array element sequence of the non-conductive acoustic matching layer310as one conceptual bundle with dashed lines. Moreover, regarding Embodiment 3, only parts differing from Embodiment 2 are described and descriptions of other overlapping areas are omitted. Moreover, the number of first grooves310aand second grooves310bshown inFIG. 18is conceptually shown.

As shown inFIG. 18, in the ultrasonic transducer of Embodiment 3, both the first grooves310aand the second grooves310bprovided in the non-conductive acoustic matching layer310are inclined. Moreover, the grooves indicated by solid lines inFIG. 18are the second grooves310b, and the grooves indicated by dashed lines are the first grooves310a.

That is, the second grooves310bin Embodiment 3 are provided inclining towards the element array direction, and the first grooves310aare also provided inclining towards the element array direction. Moreover, in the same manner as Embodiment 2, the second grooves310band the first grooves310aintersect at the mid-way point of the front-back direction (refer to the z direction ofFIG. 1) of the non-conductive acoustic matching layer310. Moreover, as shown inFIG. 18, at least one or more of the crossing part310fat which the second grooves310band the first grooves310aintersect is provided in each non-conductive acoustic matching layer310.

Moreover, the groove pitch of the second grooves310band the first grooves310ain Embodiment 3 may be set according to the groove pitch examples 1 to 4 described in Embodiment 2.

The function and effect of the ultrasonic transducer and the ultrasonic probe related to Embodiment 3 are described.

In the ultrasonic transducer of Embodiment 3, the first grooves310aare provided for each non-conductive acoustic matching layer reaching from the boundary surface (back surface of the non-conductive acoustic matching layer310), with the front surface electrode leading up to the mid-way point. Furthermore, the second grooves310bare provided leading from the boundary surface with the conductive acoustic matching layer (front surface of the non-conductive acoustic matching layer310) to the mid-way point of the non-conductive acoustic matching layer310. The mid-way point is the location further backwards than the front edge of the first grooves310a. Moreover, the crossing part310fis formed by the first grooves310aand second grooves310b. As a result, the through hole leading from the boundary surface with the front surface electrode to the boundary surface with the conductive acoustic matching layer is formed. Furthermore, the conductive film310cis provided passing from at least the edge of the back surface side to the edge of the front surface side (area leading up to the conductive acoustic matching layer) inside the first grooves310aand the second grooves310b. In other words, the conductive film is provided passing the rear edge of first grooves310ato the front edge of the second grooves310b.

Accordingly, by means of providing the first grooves310aand the second grooves310b, the conductive path may be formed on the non-conductive acoustic matching layer310by the process of forming the through hole and the process of providing the conductive path on the through hole alone. Furthermore, the non-conductive material block, conductive material block, and piezoelectrics material block are layered in order to form the layered body. Next, by means of providing the split cells in the xy direction with respect to the layered body, the two-dimensional array of the element is formed, configured by comprising the piezoelectrics, non-conductive acoustic matching layer310, and the layered body of the conductive acoustic matching layer.

According to the ultrasonic transducer manufactured by the manufacturing process, forming the conductive path of the non-conductive acoustic matching layer310may be made easier. Consequently, both may be achieved that complications in the manufacturing process of the ultrasonic transducer are avoided and the conductive path from the front surface electrode to the front substrate is formed. That is, it is a configuration in which the first grooves310a, the second grooves310b, and the conductive film are present in the non-conductive acoustic matching layer310, the manufacturing process thereof is simple, and furthermore, the conductive path may be provided without fail from the front surface electrode to the conductive acoustic matching layer.

Next, modified examples of the ultrasonic transducer of Embodiments 1 to 3 mentioned above are described. Regarding the configuration of the ultrasonic transducer mentioned above, the conductive acoustic matching layers (111, etc.) are arranged on the front surface side of the non-conductive acoustic matching layers (110, etc.), and the front substrates (122, etc.) are arranged on the front surface side of the conductive acoustic matching layer. Moreover, the non-conductive acoustic matching layer and the front substrate are electrically connected via the conductive acoustic matching layer. However, the ultrasonic transducers of the embodiments are not limited to the configurations. For example, it may be a configuration in which the front substrate is provided on the front surface side of the non-conductive acoustic matching layer without comprising the conductive acoustic matching layer.

In the ultrasonic transducer of Embodiment 1 to Embodiment 3 in which the modified embodiment was applied, both avoiding complications in forming the conductive path of the non-conductive acoustic matching layer and forming the conductive path from the front surface electrode to the front substrate may be achieved.

The embodiments of the present invention were described; however, the embodiments described above were presented as examples and are not intended to limit the range of the invention. The new embodiments may be carried out in various other configurations, and various abbreviations, replacements, and changes may be made in a range not departing from the summary of the invention. These embodiments and deformations thereof are included in the range and summary of the invention and included in the invention described in the range of patent claims as well as the range of the equivalent thereof.

EXPLANATION OF SYMBOLS