JP5228924B2 - Vibration element, ultrasonic device using the vibration element, and method for manufacturing vibration element - Google Patents

Description

  The present invention relates to a vibration element, an ultrasonic device using the vibration element, and a method for manufacturing the vibration element.

In the field of medical ultrasonic diagnostic equipment and non-destructive testing equipment, in order to image the internal state of an object, an ultrasonic wave is irradiated toward the object, and from the interface where the acoustic impedance of the object is different. An ultrasonic probe that receives a reflected echo is used.
A general ultrasonic probe includes a piezoelectric element mainly made of ceramics, a matching layer and an acoustic lens disposed on the front surface of the piezoelectric element, a backing material disposed on the back surface of the piezoelectric element, and wiring connected to the piezoelectric element. It is composed of the body. In many cases, a flexible printed wiring board is used as the wiring body.
Conventionally, in the mounting of an ultrasonic probe, a piezoelectric element made of ceramic and a flexible printed wiring board are connected by soldering. There exists the following patent document 1 as such.
The ultrasonic probe shown in the following Patent Document 1 has an advantage that the number of parts of the connection conductor connected to the transducer electrode can be reduced, and accordingly, a predetermined joining process can be reduced and the productivity can be improved.

Japanese Patent Laid-Open No. 11-151239

However, the ultrasonic probe shown in the above-mentioned patent document 1 connects the transducer electrode and the connection conductor by soldering. Therefore, when resin or a composite material of resin and ceramics is used as the piezoelectric material constituting the vibrator, it cannot withstand the temperature at which the resin is soldered, and the vibrator electrode and the connection conductor cannot be connected. There was a problem.
In addition, when only ceramics are used as the piezoelectric material constituting the vibrator, there is a problem that when the thin piezoelectric material is soldered, the solder wraps around the back surface of the piezoelectric material and becomes conductive.

  Therefore, the present invention solves the above-mentioned conventional problems, and the connection between the piezoelectric element and the flexible printed wiring board is easy and strong even when using only a resin, a composite material of resin and ceramics, or ceramics as the piezoelectric material. It is an object of the present invention to provide a vibration element with high manufacturing efficiency, an ultrasonic device using the vibration element, and a method for manufacturing the vibration element.

  The vibration element according to the present invention is a vibration element in which a piezoelectric element and a wiring body are joined at mutual electrode portions, and the joining between the mutual electrode portions of the piezoelectric element and the wiring body is anisotropic. The first feature is that the electrode portion of the piezoelectric element is provided with a recess that allows the anisotropic conductive film to enter.

  According to the first aspect of the present invention, a vibration element in which a piezoelectric element and a wiring body are joined to each other by electrode portions, between the piezoelectric element and the mutual electrode portions of the wiring body. Are bonded via an anisotropic conductive film, and the electrode portion of the piezoelectric element is provided with a recess allowing the penetration of the anisotropic conductive film. The softened anisotropic conductive film does not flow and thin when pressed to reduce the distance between the piezoelectric element and the wiring body and does not diffuse beyond a predetermined range. If the distance between the piezoelectric element and the wiring body is too short, the film thickness that contributes to adhesion becomes thin and breaks easily. For this reason, there is a concern that the adhesive strength is reduced, but if there is a recess, the film remains thick in the recess, so that the overall adhesive strength can be maintained. As a result, the piezoelectric element and the wiring body can be joined more firmly, and a vibration element with high manufacturing efficiency can be obtained.

  In addition to the feature described in the first aspect of the present invention, the piezoelectric element of the present invention has a second feature that the recess is linear.

  According to the second feature of the present invention, in addition to the function and effect of the first feature of the present invention, since the recess is configured to be linear, the atmosphere is enclosed in the recess. There is nothing. As a result, the anisotropic conductive film can be further sufficiently penetrated into the recess. Accordingly, the piezoelectric element and the wiring body can be joined more firmly.

  In addition to the features described in the first or second aspect of the present invention, the piezoelectric element of the present invention has a third feature that the wiring body is a flexible printed wiring board.

  According to the third feature of the present invention, in addition to the function and effect of the first or second feature of the present invention, the wiring body is a flexible printed wiring board. As a result, it is possible to satisfactorily transmit the drive signal and the reception signal between the wiring body and the wiring body, and to narrow the signal line and to be flexible, so that the vibration element can be formed compactly. . Moreover, it is suitable for the heating process in anisotropic conductive film connection rather than other wiring materials, such as a flat cable.

  In addition to the feature described in any one of the first to third aspects of the present invention, the piezoelectric element of the present invention is characterized in that the piezoelectric element is formed of a composite of ceramics and resin. 4 features.

  According to the fourth aspect of the present invention, in addition to the function and effect of any one of the first to third aspects of the present invention, the piezoelectric element is formed of a composite of ceramics and resin. Therefore, by using a composite of ceramics and resin as a piezoelectric element, the resin acts as a damper, and the pulse width is shortened by suppressing free vibration after ultrasonic generation of the vibration element. can do. This improves the resolution. In addition, a piezoelectric element having an acoustic impedance close to that of a living body can be obtained, and acoustic loss is reduced and sensitivity is increased. Accordingly, a high-definition vibration element can be obtained.

  In addition to the features described in any one of the first to fourth aspects of the present invention, in the piezoelectric element of the present invention, the connection portion of the piezoelectric element with the wiring body is formed only of ceramics. Is the fifth feature.

  According to the fifth aspect of the present invention, in addition to the function and effect of any one of the first to fourth aspects of the present invention, the connection portion with the wiring body in the piezoelectric element is only ceramic. Therefore, when the piezoelectric element and the wiring body are joined, the pressure can be more reliably applied and the joining strength can be improved. Therefore, it can be set as a vibration element with good manufacturing efficiency.

  In addition to the features described in any one of the first to fifth aspects of the present invention, the piezoelectric element of the present invention is characterized in that the anisotropic conductive film is composed of acicular conductive particles. This is the sixth feature.

  According to the sixth aspect of the present invention, in addition to the function and effect of any one of the first to fifth aspects of the present invention, the anisotropic conductive film is made of acicular conductive particles. Since it is comprised, while joining a piezoelectric element and a wiring body can be performed by a low pressure, conduction | electrical_connection with a piezoelectric element and a wiring body can be made favorable. Therefore, it can be set as a vibration element with good manufacturing efficiency.

  The ultrasonic device according to the present invention has a seventh feature in that the vibrator is configured by the vibration element according to any one of claims 1 to 6.

  According to the seventh aspect of the present invention, since the vibrator of the ultrasonic device is constituted by the vibration element according to any one of claims 1 to 6, the piezoelectric element constituting the vibrator. And the wiring body can be easily and firmly joined together, and an ultrasonic device with high manufacturing efficiency can be obtained.

  The method for manufacturing a piezoelectric element of the present invention is a method for manufacturing a vibration element in which a piezoelectric element and a wiring body are bonded to each other at electrode portions, and an anisotropic conductive film enters the piezoelectric element. A recess electrode portion forming step for forming an electrode portion in which a recess is formed, and an anisotropic conductive film is interposed between the recess electrode portion of the piezoelectric element and the electrode portion of the wiring body. By applying pressure while heating the anisotropic conductive film between the anisotropic conductive film interposed step, the recessed electrode portion of the piezoelectric element, and the electrode portion of the wiring body, the piezoelectric element And bonding the wiring body and allowing the softened anisotropic conductive film to enter the recess, thereby electrically connecting the recessed electrode portion of the piezoelectric element and the electrode portion of the wiring body. An eighth feature of having a heating and pressing step to be completed It is.

  According to the eighth aspect of the present invention, there is provided a method for manufacturing a vibration element in which a piezoelectric element and a wiring body are bonded to each other at an electrode portion, wherein the piezoelectric element includes an anisotropic conductive film. An anisotropic conductive film is interposed between the recess electrode portion forming step of forming an electrode portion having a recess allowing intrusion, and the recess electrode portion of the piezoelectric element and the electrode portion of the wiring body. By applying pressure while heating with an anisotropic conductive film interposed between the step of anisotropic conductive film, the recessed electrode portion of the piezoelectric element, and the electrode portion of the wiring body, the piezoelectric An element is joined to the wiring body, and a softened anisotropic conductive film is allowed to enter the recess, thereby electrically connecting the recessed electrode portion of the piezoelectric element and the electrode portion of the wiring body. And having a heating and pressing process to complete Et al., The recess electrode portion forming step, it is possible to reliably form an electrode portion formed with a recess to allow penetration of the anisotropic conductive film to the piezoelectric element. Moreover, an anisotropic conductive film can be reliably interposed between the recessed electrode portion of the piezoelectric element and the electrode portion of the wiring body by the anisotropic conductive film intervention step. In addition, the piezoelectric element and the wiring body are securely bonded by the heating and pressurizing step, and the softened anisotropic conductive film is inserted into the recess so that the electrode portion of the piezoelectric element and the electrode portion of the wiring body are It is possible to reliably complete the electrical joining.

  According to the vibration element of the present invention, the ultrasonic device using the vibration element, and the method of manufacturing the vibration element, the piezoelectric material can be used even when only a resin, a composite material of resin and ceramics, or ceramics is used. The element and the flexible printed wiring board can be connected easily and firmly, and a vibration element with high manufacturing efficiency, an ultrasonic device using the vibration element, and a method for manufacturing the vibration element can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic of the ultrasonic probe which concerns on embodiment of this invention, (a) is a top view explaining the use condition of an ultrasonic probe, (b) is a top view which simplifies and shows the internal structure of a vibrator | oscillator. FIG. 2 is a partially enlarged perspective view of FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which simplifies and shows the structure of the vibration element which concerns on embodiment of this invention, (a) is a partial expansion perspective view of a piezoelectric material, (b) is a partial expansion perspective view of an anisotropic conductive film. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which simplifies and shows the manufacturing process of the vibration element which concerns on embodiment of this invention, (a) is a perspective view of a piezoelectric element, (b) shows the state which affixed the anisotropic conducting wire film to the flexible printed wiring board. It is a perspective view. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which simplifies and shows the manufacturing process of the vibration element which concerns on embodiment of this invention, (a) is a partial expansion perspective view which shows an anisotropic conductive film intervention process, (b) is a front view which shows a heating-pressing process It is. It is a front view which shows the vibration element manufactured with the manufacturing method of the vibration element which concerns on embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is the figure which shows the modification of the vibration element which concerns on embodiment of this invention simplified, (a) is a perspective view of the piezoelectric element which comprises a vibration element, (b) joined the piezoelectric element and the flexible printed wiring board. It is a perspective view which shows a state.

  With reference to the following drawings, a vibration element according to an embodiment of the present invention, an ultrasonic device using the vibration element, and a method for manufacturing the vibration element will be described to provide an understanding of the present invention. However, the following description is an embodiment of the present invention, and does not limit the contents described in the claims.

  First, with reference to FIGS. 1 to 3, a vibration element according to an embodiment of the present invention and an ultrasonic device using the vibration element will be described.

  As shown in FIG. 1A, the resonator element according to the embodiment of the present invention mainly includes the vibrator 10, the matching layer 20 and the acoustic lens 30 disposed on the front surface of the vibrator 10, and the back surface of the vibrator 10. The transducer 10 in the ultrasonic probe 1 constituted by the backing material 40 and the coaxial cable 50 arranged in the above is configured.

The ultrasonic probe 1 is a medical ultrasonic device, and as shown in FIG. 1A, a voltage is applied to the vibrator 10 via a coaxial cable 50, whereby a piezoelectric element in the vibrator 10 is obtained. The body vibrates, and ultrasonic waves are emitted from the vibrator 10 toward the human body. At this time, the ultrasonic wave is acoustically matched by the matching layer 20, converged by the acoustic lens 30, and shaped into a beam shape. Further, the ultrasonic wave propagating to the back side of the vibrator 10 is absorbed by the backing material 40. The ultrasonic wave reflected from the human body vibrates the piezoelectric body in the vibrator 10, and an electrical signal is output from the vibrator 10 to a diagnostic machine (not shown) to perform medical diagnosis.
In the following, only the transducer 10 that forms the main part of the present invention will be described in detail, and the matching layer 20, acoustic lens 30, backing material 40, and coaxial cable 50 that form a normal configuration in the ultrasonic probe 1 will be described. Is omitted.

  As shown in FIG. 1B, the vibrator 10 includes a vibration element 100 mainly including a piezoelectric element 110, a flexible printed wiring board 120, and an anisotropic conductive film 130.

The piezoelectric element 110 is used as an ultrasonic transmission / reception element.
As shown in FIGS. 1B and 2, the piezoelectric element 110 includes an array of piezoelectric bodies 111 divided into strips (elongated rectangular parallelepiped shapes) and electrodes that cover the upper and lower surfaces of the piezoelectric body 111. Part 112. That is, as shown in FIG. 2, at the time of transmission, a voltage is applied to the electrode portions 112 covering the upper and lower surfaces of the piezoelectric body 111 to vibrate the piezoelectric body 111 and generate ultrasonic waves from the front surface 111a of the piezoelectric body 111. . At the time of reception, the piezoelectric body 111 is vibrated by the ultrasonic wave hitting the front surface 111 a of the piezoelectric body 111, and an electric signal is output from the electrode portion 112.

Further, as shown in FIGS. 1B and 2, the piezoelectric bodies 111 divided into strips (elongated rectangular parallelepiped shapes) are separated into the respective piezoelectric bodies 111 as shown in FIG. 1B. The signal line 121a is joined. With such a configuration, the intensity and phase of the input voltage can be changed, and the intensity and phase of an electric signal generated by vibration for each individual piezoelectric body 111 can be read. Medical diagnosis can be performed.
The thickness of the piezoelectric element 110 is determined by the frequency constant of the piezoelectric body 111, and is preferably 240 to 300 μm at 5 MHz and 120 to 150 μm at 10 MHz.

Further, as shown in FIG. 3A, the piezoelectric body 111 is formed of a composite body having a structure in which a piezoelectric ceramic 111c is erected in an epoxy resin 111b. By using such a piezoelectric body 111, the epoxy resin 111b serves as a damper, and the pulse width can be shortened by suppressing free vibration of the piezoelectric element 110 after generation of ultrasonic waves. This improves the resolution. In addition, a piezoelectric element having an acoustic impedance close to that of a living body can be obtained, and acoustic loss is reduced and sensitivity is increased. Accordingly, a high-definition vibration element 100 can be obtained. Therefore, the ultrasonic probe 1 can be a highly accurate ultrasonic device, and a clear image can be obtained.
As the piezoelectric ceramic 111c, it is desirable to use a material obtained by adding niobium to lead zirconate titanate (PZT). When the center frequency is 10 MHz, the diameter is preferably 50 μm or less, and when 5 MHz, the diameter is preferably 100 μm or less.

Further, as shown in FIG. 1B, the electrode portion 112, which is a joint portion of the piezoelectric body 111 with the flexible printed wiring board 120, is parallel to the longitudinal direction of the piezoelectric body 111 and is linear (elongated groove shape). The recessed portions 111d are provided at regular intervals, and the recessed electrode portions 112a are covered.
It is desirable that the depth of the recess 111d is 20 μm, the width is 0.2 mm, the pitch between the adjacent recesses 111d is 0.5 mm, and the number is three. The shape of the recess 111d is not necessarily limited to a linear shape, and can be changed as appropriate, such as a circular or polygonal hole, a discontinuous straight line, or a curved line.

The electrode section 112 is for applying a voltage to the piezoelectric body 111 during transmission and outputting vibration of the piezoelectric body 111 as an electrical signal during reception.
Note that it is desirable to use Au or Ag as the electrode portion 112.

  The flexible printed wiring board 120 is a wiring body on which the piezoelectric element 110 is mounted, and includes a printed wiring part 121 and an electrode part 122 as shown in FIGS.

  The printed wiring portion 121 includes a signal line 121a and is made of a polyimide film. Further, as shown in FIG. 1B, the signal line 121a is formed corresponding to each pitch of the piezoelectric elements 111 that form an array divided into strips (elongate rectangular parallelepipeds). With such a configuration, the intensity and phase of the voltage input to the piezoelectric body 111 can be changed, and the intensity and phase of an electric signal generated by vibration for each piezoelectric body 111 can be read. More detailed medical diagnosis.

The electrode unit 122 is joined to the electrode unit 112 of the piezoelectric body 111 so that a voltage is applied to the electrode unit 112 of the piezoelectric body 111 at the time of transmission, and the vibration of the piezoelectric body 111 is not shown as an electrical signal at the time of reception. It is for output to the machine. It is desirable to use Cu as the electrode part 122.
As described above, by using the flexible printed wiring board 120 as the wiring body, it is possible to satisfactorily transmit the drive signal and the reception signal between the piezoelectric element 110 and the flexible printed wiring board 120, and to transmit the signal line 121a. Can be made fine pitch.

The anisotropic conductive film 130 is for electrically joining the piezoelectric body 111 and the flexible printed wiring board 120.
This anisotropic conductive film 130 has conductive particles 132 in a film 131 as shown in FIG. It becomes soft when heated, and the distance between the piezoelectric body 111 and the flexible printed wiring board 120 approaches by applying pressure simultaneously. At this time, the conductive particles 132 are inserted between the piezoelectric body 111 and the flexible printed wiring board 120 to conduct. By continuing the heating, the film 131 is cured, and the piezoelectric body 111 and the flexible printed wiring board 120 are bonded.
Note that an epoxy resin or an acrylic resin is preferably used as the film 131, and needle-like nickel particles are preferably used as the conductive particles 132. By using the acicular nickel particles, the piezoelectric element 110 and the flexible printed wiring board 120 can be joined to each other at a low pressure, and the piezoelectric element 110 and the flexible printed wiring board 120 are electrically connected. It can be good. Therefore, the vibration element 100 with good manufacturing efficiency can be obtained. The aspect ratio of the acicular nickel particles is preferably 5 or more.
Here, “aspect ratio” means the ratio of length to particle diameter.

Next, a method for manufacturing the vibration element 100 will be briefly described with reference to FIGS.
As shown in FIG. 2, the vibration element 100 is for bonding the flexible printed wiring board 120 to the upper and lower surfaces of the electrode portion 112 in the piezoelectric element 110, but the bonding method of the piezoelectric element 110 and the flexible printed wiring board 120 is also used. Since the same applies to the upper surface and the lower surface of the piezoelectric element 110, only the bonding with the flexible printed wiring board 120 on the upper surface of the piezoelectric element 110 will be described in the following description.

First, referring to FIG. 4A, a piezoelectric element 110 is prepared in which an upper surface of a piezoelectric body 111 is covered with an electrode portion 112. In the piezoelectric element 110, as shown in FIG. 4A, recesses 111d including the recess electrode portions 112a are formed at regular intervals. The recess 111d provided with the recess electrode portion 112a is parallel to the longitudinal direction of the piezoelectric body 111 and has the same length at the joint portion of the piezoelectric body 111 with the flexible printed wiring board 120 by a recess electrode portion forming process (not shown). Then, after forming a linear (long and narrow groove-shaped) recess 111d, the electrode 112 is covered.
Note that Au or Ag is preferably used for the electrode portion 112. The method for coating the electrode part 112 on the piezoelectric body 111 may be any method as long as it is normally used as a method for forming the electrode part in the piezoelectric element.

  When a vibration element having a center frequency of 10 MHz is manufactured, it is desirable that the length of the piezoelectric element 110 in the longitudinal direction is 40 mm, the length in the short direction is 8 mm, and the thickness is 120 μm to 150 μm. It is desirable that the depth of the recess 111d is 20 μm, the width is 0.2 mm, the pitch between the adjacent recesses 111d is 0.5 mm, and the number is three. The shape of the recess 111d is not necessarily limited to a linear shape, and can be changed as appropriate, such as a circular or polygonal hole, a discontinuous straight line, or a curved line.

And the flexible printed wiring board 120 which affixed the anisotropic conductive film 130 on the electrode part 122 is prepared as shown in FIG.4 (b). The flexible printed wiring board 120 and the anisotropic conductive film 130 are attached by heating the anisotropic conductive film 130 to 70 ° C. in an anisotropic conductive film attaching process (not shown).
The length of the anisotropic conductive film 130 in the longitudinal direction is preferably 40 mm and the length in the short direction is 1.2 mm. In other words, in a softened state, it is desirable that the size is large enough to seal the three recesses 111d.

  Moreover, the flexible printed wiring board 120 is formed by coating the electrode part 122 on the joint surface with the anisotropic conductive film 130 in the printed wiring part 121 as shown in FIG. It is desirable to use Cu as the electrode part 122. Further, the method of covering the printed wiring part 121 with the electrode part 122 may be any method as long as it is normally used as a method for forming the electrode part on the flexible printed wiring board.

  5A, the anisotropic conductive film is interposed between the recess electrode portion 112a of the piezoelectric element 110 and the electrode portion 122 of the flexible printed wiring board 120 in the anisotropic conductive film intervening step. A rubber sheet 200 and a heat tool 300 are prepared with 130 interposed. As the rubber sheet 200, it is desirable to use a silicon rubber sheet.

  5B, an anisotropic conductive film 130 is interposed between the recessed electrode portion 112a of the piezoelectric element 110 and the electrode portion 122 of the flexible printed wiring board 120 in the heating and pressing step. In this state, the heat tool 300 is set to 260 ° C. through the rubber sheet 200, and the anisotropic conductive film 130 is heated. At this time, the actual temperature of the anisotropic conductive film 130 was 180 ° C. Then, with the anisotropic conductive film 130 softened, the load of the heat tool 300 is set to 80 N, and the piezoelectric element 110, the flexible printed wiring board 120, and the anisotropic conductive film 130 are pressurized while being heated. . Thereby, the piezoelectric element 110 and the flexible printed wiring board 120 can be electrically and mechanically connected by the anisotropic conductive film 130.

  Through the above steps, as shown in FIG. 6, the piezoelectric element 110 and the flexible printed wiring board 120 are joined by the mutual electrode portions 112 and 122, and the recessed electrode portion 112 a and the electrode of the flexible printed wiring board 120 are joined. Adhesion with the portion 122 is completed. Then, the piezoelectric element 110 and the flexible printed wiring board 120 are divided into strips (elongated rectangular parallelepiped shape) using a cutting machine such as a dicing saw or a cutting saw (not shown), whereby the vibration element 100 is manufactured.

By manufacturing the vibration element 100 using the above manufacturing method, the following effects can be obtained.
First, by applying pressure while heating the piezoelectric element 110 and the flexible printed wiring board 120 with the anisotropic conductive film 130 interposed between the recess 111d of the piezoelectric body 111 and the flexible printed wiring board 120, The anisotropic conductive film 130 is melted and the distance between the piezoelectric element 110 and the flexible printed wiring board 120 is reduced, and the conductive film 132 can be conducted. Further, by continuing the heating for a predetermined time, the anisotropic conductive film 130 is cured, and the piezoelectric element 110 and the flexible printed wiring board 120 are mechanically bonded. At this time, since there is the recess 111d, the molten film other than that contributing to the connection between the piezoelectric element 110 and the flexible printed wiring board 120 enters the recess 111d and does not flow out beyond the predetermined range. Further, the anisotropic conductive film 130 entering the recess 111d can be cured to maintain the adhesive strength.

  In addition, as shown in FIG. 4, the recess 111d has a shape that is parallel to the longitudinal direction of the piezoelectric body 111, has the same length, and has a linear shape (a long and narrow groove shape). As described above, the size is large enough to completely seal the three recesses 111d in the softened state. Therefore, in the heating and pressurizing step, it is possible to reliably prevent air from being caught in the three recesses 111d.

  As described above, the piezoelectric body 111 is composed of a composite body having a structure in which the piezoelectric ceramic 111c is erected in the epoxy resin 111b. Therefore, when the heat resistance temperature of the epoxy resin 111b is 200 degrees or less, the piezoelectric body 111 is a composite composed of the epoxy resin 111b and the piezoelectric ceramic 111c by setting the heating temperature in the heating and pressurizing step to 180 ° C. Even in this case, the connection between the piezoelectric elements 110 and the flexible printed wiring board 120 at the mutual electrode portions can be easily and reliably performed.

  In addition, by using the anisotropic conductive film 130, it is possible to reliably prevent conduction even when the anisotropic conductive film 130 wraps around the back surface of the piezoelectric body 111 in the heating and pressurizing step. This is because the anisotropic conductive film 130 can be electrically connected only at a place where pressure is applied. Therefore, it is easy to attach the flexible printed wiring board 120 to the piezoelectric element 110 having a small thickness.

  Further, the piezoelectric element 110, the flexible printed wiring board 120, and the anisotropic conductive film 130 are pressed while being heated via the rubber sheet 200, thereby preventing the piezoelectric element 110 from being bent in the heating and pressing step. be able to.

In the present embodiment, the joint portion of the piezoelectric element 110 with the flexible printed wiring board 120 is a composite composed of the epoxy resin 111b and the piezoelectric ceramic 111c, but is not necessarily limited to such a configuration. It is not a thing and it can change suitably.
For example, as shown in FIG. 7, it can be set as the structure which forms the junction part with the flexible printed wiring board 120 in the piezoelectric element 110 only with the piezoelectric ceramic 111c. With such a configuration, the piezoelectric element 110 having sufficient durability can be obtained even when heat or pressure is applied to the piezoelectric element 110 in the heating and pressing step. In addition, the joining portion of the piezoelectric element 110 with the flexible printed wiring board 120 can be made thin, and the pressure applied to the anisotropic conductive film 130 can be performed more easily and reliably. Therefore, the vibration element 100 with good manufacturing efficiency can be obtained.

In the present embodiment, the flexible printed wiring board 120 is used as the wiring body. However, the configuration is not necessarily limited thereto. For example, a flat cable can be used.
In the present embodiment, the vibration element 100 is used in a medical ultrasonic device. However, the present invention is not necessarily limited to such a configuration, and any ultrasonic device including a vibration element having a piezoelectric element may be used. It may be used for things. For example, it can be used for ultrasonic flaw detectors and non-destructive inspection equipment.

  The present invention can be used for an ultrasonic device including a vibration element having a piezoelectric element.

DESCRIPTION OF SYMBOLS 1 Ultrasonic probe 10 Vibrator 20 Matching layer 30 Acoustic lens 40 Backing material 50 Coaxial cable 100 Vibration element 110 Piezoelectric element 111 Piezoelectric body 111a Front surface 111b Epoxy resin 111c Piezoelectric ceramic 111d Recess 112 Electrode part 112a Recessed electrode part 120 Flexible print Wiring board 121 Printed wiring part 121a Signal line 122 Electrode part 130 Anisotropic conductive film 131 Film 132 Conductive particle 200 Rubber sheet 300 Heat tool

Claims (8)

  A vibration element in which a piezoelectric element and a wiring body are joined at mutual electrode portions, and the joining between the mutual electrode portions of the piezoelectric element and the wiring body is joined via an anisotropic conductive film. And a recess for allowing the anisotropic conductive film to enter the electrode portion of the piezoelectric element.   The vibrating element according to claim 1, wherein the recess is linear.   The vibrating element according to claim 1, wherein the wiring body is a flexible printed wiring board.   The vibration element according to claim 1, wherein the piezoelectric element is formed of a composite of ceramics and resin.   5. The vibration element according to claim 1, wherein a connection portion of the piezoelectric element with the wiring body is formed only of ceramics.   The vibrating element according to claim 1, wherein the anisotropic conductive film is composed of acicular conductive particles.   An ultrasonic device, wherein the vibrator is configured by the vibration element according to any one of claims 1 to 6.   A method of manufacturing a vibration element in which a piezoelectric element and a wiring body are bonded to each other by an electrode part, wherein an electrode part in which a recess allowing an anisotropic conductive film to penetrate is formed in the piezoelectric element. A recess electrode portion forming step to be formed; an anisotropic conductive film interposing step of interposing an anisotropic conductive film between the recess electrode portion of the piezoelectric element and the electrode portion of the wiring body; and the piezoelectric element By applying pressure while heating an anisotropic conductive film between the recessed electrode part and the electrode part of the wiring body, the piezoelectric element and the wiring body are joined, And a heating and pressing step of completing electrical bonding between the recessed electrode portion of the piezoelectric element and the electrode portion of the wiring body by allowing the softened anisotropic conductive film to enter the recessed portion. A method for manufacturing a vibrating element.

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