JP2016063499A - Transducer and analyte information acquisition device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transducer or the like such as a capacitive transducer having high insulation between an electrode or wiring and a surface of the transducer.SOLUTION: In the capacitive transducer, a first electrode 101 and a second electrode 102 which are disposed on a substrate 100 are connected with an external circuit via a flexible substrate 300. The first and second electrodes are electrically connected in a portion that is opposite to wiring in a region where top and bottom faces are not held between insulation films 302 and 303 within the flexible substrate. A surface of the wiring or an electrode electrically connected with the first and second electrodes on the substrate is covered by insulation layers 201 and 202 which are deposited on the substrate, or an insulation film that the flexible substrate includes.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a capacitive transducer that performs at least one of transmission and reception of an acoustic wave such as an ultrasonic wave (hereinafter sometimes represented by an ultrasonic wave), and a subject information acquisition apparatus using the capacitive transducer. .

  As a transducer for transmitting and receiving ultrasonic waves, there is a capacitive type CMUT (Capacitive Micromachined Ultrasonic Transducer). The CMUT can be manufactured using a MEMS (Micro Electro Mechanical Systems) process that applies a semiconductor process. This is characterized in that the width of the ultrasonic transmission frequency and the width of the reception frequency are wider than those of the ultrasonic transducer using the piezoelectric element.

  As shown in FIG. 10, in the CMUT, for example, a first electrode (lower electrode) 13 is arranged as a fixed electrode on a substrate 10, and a gap or cavity (cavity) 15 is formed on the first electrode 13. The vibration film 11 is disposed via the. A second electrode (upper electrode) 12 is disposed on the vibration film 11 so as to face the first electrode 13 (see Non-Patent Document 1). The vibration film 11 is supported by a support portion 14 disposed on the substrate 10, and the vibration film 11 vibrates by applying a pulsed potential difference between the first electrode 13 and the second electrode 12. , Ultrasonic waves are generated and propagated outside (transmission of ultrasonic waves). On the other hand, when the ultrasonic wave from the outside is transmitted to the vibration film 11, the second electrode 12 also vibrates, and a minute current is generated by changing the distance between the first electrode 13 and the second electrode 12. By detecting this minute current, an ultrasonic reception signal can be extracted (acoustic reception).

  Here, the first electrode 13 is connected to the DC voltage generation circuit 32 via the wiring 22. The second electrode 12 is connected to the transmission / reception circuit 31 through the wiring 21. The DC voltage generation circuit 32 generates a DC voltage Va of several tens of volts to several hundreds of volts, and the first electrode 13 is connected by the wiring 22, so the same Va is applied. The terminal of the transmission / reception circuit 31 is set to be 0 volt inside the circuit 31, and the second electrode 12 is connected to the wiring 21, and thus is fixed at a potential of 0 volt. For this reason, a potential difference of Va (= Va-0) volts is always generated between the first electrode 13 and the second electrode 12, and this potential difference is effective in transmitting and receiving ultrasonic waves. The CMUT is used by setting it to be higher.

  On the other hand, the transmission / reception circuit 31 has a function of converting a minute current generated at the electrode into a voltage when receiving an ultrasonic wave and outputting the voltage, and a function of generating a high voltage pulse of several tens to several hundreds of volts when transmitting an ultrasonic wave. have. The high voltage pulse generated in the transmission / reception circuit 31 is transmitted to the second electrode 12 through the wiring 21 and changes the potential difference generated between the first electrode 13 and the second electrode 12. As a result, the electrostatic attractive force generated between the electrodes changes, and the vibration film 11 vibrates and can generate ultrasonic waves. The roles of the first electrode 13 and the second electrode 12 may be opposite to those described above.

AS Ergun, Y. Huang, X. Zhuang, O. Oralkan, GG Yarahoglu, and BT Khuri-Yakub, "Capacitive micromachined ultrasonic transducers: fabrication technology," Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, vol. 52, no 12, pp. 2242-2258, Dec. 2005.

  A capacitive transducer such as CMUT needs to apply a high DC voltage or a high voltage pulse to the electrodes in order to transmit and receive ultrasonic waves as described above. Therefore, a high voltage is applied to the electrode of the CMUT, the wiring that connects the electrode and the circuit, and the portion that connects the electrode and the wiring. However, when the CMUT is used as a transducer of an ultrasonic diagnostic imaging apparatus, it may be used in contact with a living body that is a subject. Therefore, in order to ensure safety for a living body, it is necessary to reliably insulate between the CMUT electrode, the wiring connecting the electrode and the circuit, and the connection portion between the electrode and the wiring, and the transducer surface in contact with the outside. . An object of the present invention is to provide a transducer, an object information acquisition device, and the like having high insulation between an electrode, wiring, and the like and a transducer surface.

  In view of the above problems, the present invention has one or more cells each including one or more cells including a first electrode and a vibration film including a second electrode formed at a distance from the first electrode on a substrate. The capacitive transducer has the following characteristics. A first wiring electrically connected to the first electrode; a first connection electrode electrically connected to the first wiring; and a second wiring connected to the second electrode A second connection electrode electrically connected to the second wiring, a third connection electrode disposed opposite to the first connection electrode and the second connection electrode on the substrate, and And a flexible substrate having a fourth connection electrode. The space between the third connection electrode and the fourth connection electrode of the flexible substrate and the first connection electrode and the second connection electrode is narrower than the size of the particles of the anisotropic conductive resin. Are electrically connected to each other. And the said electrode on the said board | substrate, the said wiring, and the said connection electrode are covered with the insulating film which the flexible layer has on the insulating layer formed on this board | substrate.

  According to the present invention, it is possible to provide a capacitive transducer having high insulation between the electrode, wiring, and the like and the transducer surface by the covering structure as described above.

FIG. 3 is a schematic diagram illustrating a capacitive transducer according to the first embodiment. FIG. 3 is a schematic diagram illustrating a capacitive transducer according to the first embodiment. FIG. 3 is a schematic diagram illustrating a capacitive transducer according to the first embodiment. The schematic diagram explaining the capacitive transducer which concerns on 2nd Embodiment. The schematic diagram explaining the capacitive transducer which concerns on 3rd Embodiment. FIG. 10 is a schematic diagram illustrating a capacitive transducer according to a fourth embodiment. FIG. 9 is a schematic diagram for explaining a capacitive transducer according to a fifth embodiment. FIG. 10 is a schematic diagram illustrating a capacitive transducer according to a sixth embodiment. The schematic diagram explaining the example of a subject information acquisition apparatus. The figure explaining the conventional ultrasonic probe.

  In the transducer of the present invention, the substrate has one or more cells including a first electrode and a second electrode formed by separating the first electrode and the insulating portion, and an electrode on the substrate, a wiring, The connection electrode is covered with an insulating layer formed on the substrate and an insulating film of the flexible substrate. The insulating part may be a piezoelectric element or the like, but typically, the transducer is a capacitance type having a cell including a vibration film including a second electrode formed at a distance from the first electrode. It is a transducer.

  In the present invention, in order to solve the above problems, attention is paid to a wiring portion that connects an electrode and an external circuit. The transducer of the present invention uses a flexible substrate and connects the connection electrode on the substrate and the connection electrode on the flexible substrate to an anisotropic conductive resin (thin anisotropic conductive film (ACF) or anisotropic conductive paste (ACP). ) Etc.) for electrical connection. A conductive portion to which a voltage is applied, such as an electrode and a wiring on the substrate, is covered with either an insulating layer formed on the substrate or an insulating film of the flexible printed board. To do. Hereinafter, although embodiment of this invention is described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

Embodiments of a transducer according to the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic diagram of the capacitive transducer according to the first embodiment. 1A is a plan view, FIG. 1B is a cross-sectional view taken along a line AB, and FIG. 1C is a cross-sectional view taken along a line CD. FIG. 2 is a schematic diagram for explaining the substrate 100 of the capacitive transducer according to this embodiment shown in FIG.

  In these figures, 100 is a substrate, 101 is a first electrode, 102 is a second electrode, 103 is a gap or cavity, 104 is a vibrating membrane, 105 is a support portion, 111 is a first wiring, 112 Is a second wiring, 113 is a first connection electrode, and 114 is a second connection electrode. Reference numeral 201 denotes a first insulating layer, 202 denotes a second insulating layer, 211 denotes a first electrode layer, 212 denotes a second electrode layer, and 300 denotes a flexible printed wiring board which is a flexible board. Furthermore, 301 is a conductive film, 302 is a first insulating film, 303 is a second insulating film, 311 is a third connection electrode, 312 is a fourth connection electrode, 313 is a third wiring, and 314 is a fourth wiring. , 401 is a first anisotropic conductive resin, and 402 is a second anisotropic conductive resin. 900 is a cell.

  A first electrode 101 is disposed as a fixed electrode on the substrate 100, and a vibration film 104 is disposed on the first electrode 101 with a gap 103 interposed therebetween. On the vibration film 104, the second electrode 102 is disposed so as to face the first electrode 101. The vibration film 104 is supported by a support portion 105, and the vibration film 104 and the second electrode 102 vibrate. The first electrode 101 is connected to a DC voltage generation circuit (not shown) by a first wiring 111 on the substrate 100 and a third wiring 313 on the flexible printed wiring board 300. The first wiring 111 and the third wiring 313 are connected between the first connection electrode 113 connected to the first wiring 111 and the third connection electrode 311 connected to the third wiring 313. They are electrically connected by an anisotropic conductive resin 401. The second electrode 102 is connected to a transmission / reception circuit (not shown) by a second wiring 112 on the substrate 100 and a fourth wiring 314 on the flexible printed wiring board 300. The second wiring 112 and the fourth wiring 314 are connected between the fourth connection electrode 114 connected to the second wiring 112 and the fourth connection electrode 312 connected to the fourth wiring 314. They are electrically connected by an anisotropic conductive resin 401.

  The substrate 100 and the CMUT formed thereon will be described with reference to FIG. As the substrate 100, an insulating substrate is used. The first electrode 101 is constituted by a first metal layer 211 formed on the substrate 100 by film formation. The first electrode 101 is set to a thickness that can realize a resistance necessary for obtaining a required transmission / reception efficiency and a required roughness of the electrode surface. The vibration film 104 and the support part 105 are configured by a first insulating layer 201 formed by film formation on the first metal layer 211. The first insulating layer 201 covers the first electrode 101 and has a function of insulating the metal layers arranged above and below the first insulating layer 201. The second electrode 102 is configured by a second metal layer 212 formed by film formation on the first insulating layer 201. The second electrode 102 is set to a thickness that can realize a necessary resistance for obtaining a required transmission / reception efficiency and a mechanical characteristic necessary for the vibrating membrane. The second electrode 102 is covered with a second insulating layer 202 formed by film formation on the second metal layer 212. Since the second electrode 102 is covered with the second insulating layer 202, electrical insulation from the outside is maintained.

  In the present embodiment, the first wiring 111 and the first connection electrode 113 are configured by the first metal layer 211 formed on the substrate 100 by film formation, similarly to the first electrode 101. The first metal layer 211 is composed of the same layer as the electrode layer constituting the first electrode. The first wiring 111 electrically connects the first electrode 101 and the first connection electrode 113. As described above, the first insulating layer 201 is formed on the first metal layer 211 by film formation. A portion of the first wiring 111 formed of the first metal layer and the first connection electrode 113 are not covered with the first insulating layer 201. This can be easily realized by using a MEMS technique such as a method of selectively forming an insulating layer or a method of selectively removing a part of the region by etching after the insulating layer is formed. The reason why the portion not covered with the first insulating layer 201 is formed is that the exposed portion of the connection electrode 113 and the connection electrode 311 of the flexible printed wiring board 300 are electrically connected by the first anisotropic conductive resin 401. There is to connect. As a secondary matter, a portion where the anisotropic conductive resin escapes may be formed so that the second anisotropic conductive resin 402 of the insulating portion is formed there.

  The second electrode 102, the second wiring 112, and the second connection electrode 114 are configured by the second metal layer 212 formed over the first insulating layer 201. In the region where the second connection electrode 114 is disposed, the first insulating layer 201 is not disposed. Therefore, the second wiring 112 is electrically connected across the step between the first insulating layer 201 and the substrate 100. The second connection electrode 114 is directly disposed on the substrate 100. The second electrode 102 including the second metal layer 212 and part of the second wiring 112 are covered with the second insulating layer 202. On the other hand, part of the second wiring 112 formed of the second metal layer 212 and the second connection electrode 114 are not covered with the second insulating layer 202. Again, the main reason for making the portion not covered with the second insulating layer 202 is to connect the exposed portion of the connection electrode 114 and the connection electrode 312 of the flexible printed wiring board 300 to the first anisotropic conductive resin 401. It is in electrical connection.

  With the above configuration, the first insulating layer 201 and the second insulating layer 202 satisfy the mechanical characteristics necessary for the vibration film. As these materials, any material that can be formed by film formation, such as a silicon nitride film, can be used. As the first metal layer 211, any metal material can be used as long as it can withstand heat when the first insulating layer 201 and the second insulating layer 202 are formed. The second metal layer 212 is a metal material that can satisfy the mechanical characteristics and electrical characteristics required for the vibration film and can withstand the heat when the first insulating layer 201 and the second insulating layer 202 are formed. Anything can be used. As these metal layers, aluminum, an aluminum alloy, tungsten, titanium, or the like can be used.

  In this embodiment, the first electrode 101 and the second electrode 102 on the substrate 100, a part of the first wiring 111 and a part of the second wiring 112 are excellent in insulating characteristics, and the insulating layer 201 is formed. , 202. Since the insulating layers 201 and 202 are formed on the electrodes by film formation, the electrodes and wirings can be reliably covered, and the electrodes and wirings and the sensor surface can be reliably electrically insulated.

  The first connection electrode 113 and the second connection electrode 114 are used as a connection portion with the flexible printed wiring board 300 for electrical connection with an external circuit. The first connection electrode 113 and the second connection electrode 114 are disposed on the substrate 100. Therefore, an anisotropic conductive resin is disposed between the connection electrodes 113 and 114 on the substrate 100 and the connection electrodes 311 and 312 on the flexible printed wiring board 300. Thus, both the first electrode 101 and the second electrode 102 can be electrically connected to the wiring of the flexible printed wiring board 300, respectively.

  FIG. 3 is a schematic diagram for explaining the flexible printed wiring board 300 of the capacitive transducer according to the present embodiment. 3 (a) is a plan view, FIG. 3 (b) is a cross-sectional view along line AB, FIG. 3 (c) is a cross-sectional view along line CD, and FIG. 3 (d) is a cross-sectional view along line EF. It is. In the present embodiment, the flexible printed wiring board 300 is used for the wiring 313 used for connection between the first connection electrode 113 and the DC voltage generation circuit, and the wiring 314 used for connection between the second connection electrode 114 and the transmission / reception circuit. Yes. The flexible printed wiring board 300 has a configuration in which a conductive layer 301 as a wiring is sandwiched between a first insulating film 302 and a second insulating film 303. In the flexible printed wiring board 300, the conductive layer 301 is covered only with the first insulating film 302 at the end on the substrate 100 side, and the conductive layer 301 on one side is exposed. In the exposed region, the connection electrodes 113 and 114 on the substrate 100 and the wirings 111 and 112 not covered by the insulating layers 201 and 202 are arranged so as to overlap each other. The connection electrodes 311 and 312 disposed in the exposed regions are disposed so as to face the connection electrodes 113 and 114 disposed on the substrate 100.

  In addition, a flexible printed wiring board 300 is disposed on the substrate 100, and an anisotropic conductive resin is filled between the region of the first insulating film 302 where the conductive layer 301 is exposed and the substrate 100. ing. An anisotropic conductive resin (ACF) is an insulating thermosetting resin containing fine conductive metal particles (having a diameter of several micrometers to several tens of micrometers). The distance between the connection electrode 113 and the connection electrode 311 that are arranged to face each other is smaller than the size of fine conductive metal particles (approximately several micrometers to about 10 micrometers) included in the anisotropic conductive resin. Therefore, the connection electrode 113 and the connection electrode 311 are electrically connected by fine conductive metal particles in a region where the connection electrodes are arranged. Similarly, the distance between the connection electrode 114 and the connection electrode 312 is smaller than the size of the fine conductive metal particles included in the anisotropic conductive resin, and is a region where the connection electrode 114 and the connection electrode 312 are arranged. The electrodes are electrically connected by metal particles. In the present embodiment, the first connection electrode 113 and the second connection electrode 114 are disposed on the same substrate 100. Accordingly, the distances between the connection electrodes 311 and 312 on the flexible printed wiring board 300 facing each other can be made uniform, and highly reliable electrical connection can be realized in a simple process. In this specification, the anisotropic conductive resin that performs electrical connection between the upper and lower connection electrodes is referred to as a first anisotropic conductive resin 401.

  On the other hand, the anisotropic conductive resin in the region where the connection electrodes 311 and 312 and the connection electrodes 113 and 114 are not arranged is equal to the electrode thickness of the connection electrode 113 and the connection electrode 311, or the connection electrode 114 and the connection electrode 312. The distance between the substrate 100 and the insulating film 302 is increased. Therefore, since no electrode is arranged in the first place, it functions as an insulating resin. Further, the distance between different electrodes on the substrate 100 or the first insulating film 302 is sufficiently larger than the size of the conductive metal particles of the anisotropic conductive resin. The different electrodes on the insulating film 302 are electrically insulated. In this specification, what functions as an insulating resin is referred to as a second anisotropic conductive resin 402 (see a portion indicated by 402 in FIG. 1). As described above, the anisotropic conductive resin that performs the insulating function fills the wiring and connection electrodes on the substrate over the region that is not covered by the insulating layer formed on the substrate.

  In this embodiment, the first electrode 101, the second electrode 102, the first wiring 111, the second wiring 112, and the connection electrodes 113, 114, 311, 312 are formed of the insulating layers 201 and 202, the first insulation. It is completely covered with either the film 302 or the second anisotropic conductive resin 402. Therefore, it is insulated from the outside. The insulating layers 201 and 202 formed on the substrate 100 can reliably cover the electrodes 101 and 102 on the substrate 100 and be insulated from the outside. In addition, since the insulating layer has high insulating properties, the thickness of the insulating layer can be reduced, and a vibration film suitable for ultrasonic transmission / reception characteristics can be obtained. The insulating film 302 can uniformly insulate the insulating layer and increase the thickness of the insulating layer. In addition, between the substrate 100 and the first insulating film 302, the regions around the connection electrodes 113 and 114 and the connection electrodes 311 and 312 are all surrounded by the insulating anisotropic conductive resin 402, so that high insulation is achieved. Sex can be secured. In this way, it is possible to provide a capacitive transducer having high insulation between the electrode or wiring and the transducer surface.

  In the present embodiment, the substrate 100 is described as an insulating substrate, but is not limited thereto. A substrate in which an insulating layer is formed on the surface using a conductive substrate can be used as well. Further, a DC voltage generating means is connected to the first electrode 101, and a transmission / reception circuit is connected to the second electrode 102, but this is not restrictive. The present embodiment can also be applied to an apparatus in which a transmission / reception circuit is connected to the first electrode 101 and a DC voltage generating means is connected to the second electrode 102. In addition, although the gap 103 is arranged between the first electrode 101 and the vibration film 104, an insulating layer such as silicon oxide formed on the upper and lower sides of the gap 103 may be additionally arranged.

  In addition, the first connection electrode is composed of the first metal layer 211 and the second connection electrode is composed of the second metal layer 212. However, the third metal layer ( A configuration in which a later-described embodiment) is arranged can also be taken. Thereby, the outermost surface of a connection electrode can be comprised with the metal material suitable for the connection between electrodes by anisotropic conductive resin. Further, since the thickness of the connection electrode can be different from the thicknesses of the first electrode 111 and the second electrode 112, it is possible to make the thickness suitable for connection. Connection can be made.

  Furthermore, only the second insulating layer 202 and the first insulating film 302 are disposed on the outermost surface of the transducer, but this embodiment is not limited to this form. It can also be used for the structure which has arrange | positioned the protective film and acoustic lens which were formed with the silicone rubber on the insulating layer or the insulating film. In this configuration, since the silicone rubber layer, which is an insulating material, is disposed on the outermost surface of the transducer, the insulating property is higher. Even if the soft silicone rubber layer is damaged, the second insulating layer 202 and the first insulating film 302 can ensure insulation.

(Second Embodiment)
The second embodiment is different in that the connection electrodes 113 and 114 are disposed on the first insulating layer 201. The rest is the same as in the first embodiment. FIG. 4 is a schematic diagram for explaining the capacitive transducer according to the second embodiment. In the present embodiment, a part of the first wiring 111 connected to the first electrode 101 is configured by the first metal layer 211. The remaining portion of the first wiring 111 connected to the first electrode 101 and the first connection electrode 113 are constituted by a second metal layer 212. As described above, in the present embodiment, the first connection electrode and the second connection electrode on the substrate are at least partially composed of the same layer as the electrode layer constituting the second electrode.

  On the first metal layer 211, the first insulating layer 201 is formed by film formation, but a part of the region has a region 500 that is not covered by the first insulating layer 201. This region 500 is called a first contact hole 500. Since this contact hole is realized by hollowing out a part of the insulating layer, it has a shape having a recess. Within the first contact hole, the first metal layer 211 and the second metal layer 212 are electrically connected. Specifically, the first wiring 111 below the first insulating layer 201 and the first connection electrode on the first insulating layer 201 are formed by the second metal layer 212 disposed on the first insulating layer 201. 113 are electrically connected in the first contact hole 500. In addition, the second wiring 112 and the second connection electrode 114 connected to the second electrode 102 are configured by the second metal layer 212 over the first insulating layer 201. A part of the second connection electrode 114 and the second wiring 112 is not covered with the second insulating layer 202 and is exposed. Again, the main reason for making the portion not covered with the second insulating layer 202 is to connect the exposed portion of the connection electrode 114 and the connection electrode 312 of the flexible printed wiring board 300 to the first anisotropic conductive resin 401. It is in electrical connection.

  As described above, the first connection electrode 113 and the second connection electrode 114 are disposed on the first insulating layer 201. The first connection electrode 311 and the second connection electrode 312 on the flexible printed wiring board 300 are electrically connected to each other by the first anisotropic conductive resin 401. In addition, the flexible printed wiring board 300 is arranged to cover the upper portion of the region not covered with the insulating layer by the first wiring 111, the first connection electrode 113, the second wiring 112, and the second connection electrode 114. Has been. A space between the region not covered with the insulating layer and the flexible printed wiring board 300 is filled with the second anisotropic conductive resin 402 and is electrically insulated from the outside.

  In the capacitive transducer according to this embodiment, since the connection electrode can be disposed on the first insulating layer 201, the distance from the conductive substrate 100 can be increased, and the parasitic capacitance at the connection electrode is reduced. be able to. Since parasitic capacitance degrades the characteristics of the transmission / reception circuit, in this embodiment, even when a conductive substrate is used, there is little degradation of the transmission / reception characteristics, and there is high insulation between the electrodes and wiring and the transducer surface. A capacitive transducer can be provided.

(Third embodiment)
The third embodiment is different in that the connection electrodes 113 and 114 are configured by the third metal layer 213. That is, in the present embodiment, the first connection electrode and the second connection electrode on the substrate are formed of a metal layer formed on the electrode layer that forms the second electrode. Other than that, it is the same as any one of the first and second embodiments.

  FIG. 5 is a schematic diagram for explaining a capacitive transducer according to the third embodiment. In the present embodiment, a part of the first wiring 111 connected to the first electrode 101 is configured by the first metal layer 211. The remaining portion of the first wiring 111 connected to the first electrode 101 and the first connection electrode 113 are constituted by a third metal layer 213. On the first metal layer 211, the first insulating layer 201 and the second insulating layer 202 are formed by film formation, but a part of the region 501 is not covered with the insulating layers 201 and 202. have. This region 501 is referred to as a second contact hole. Since this contact hole is realized by hollowing out a part of the insulating layer, it has a shape having a recess. In the second contact hole 501, the first metal layer 211 and the third metal layer 213 are electrically connected. Specifically, the first wiring 111 below the first insulating layer 201 and the first connection electrode on the second insulating layer 202 are formed by the third metal layer 213 disposed on the second insulating layer 202. The second contact holes 501 are electrically connected to each other.

  A part of the second wiring 112 connected to the second electrode 102 is constituted by the second metal layer 212. The remaining portion of the second wiring 112 connected to the second electrode 102 and the second connection electrode 114 are constituted by a third metal layer 213. On the second metal layer 212, the second insulating layer 202 is formed by film formation, but part of the region has a region 502 not covered with the second insulating layer 202. This region 502 is called a third contact hole. Since this contact hole is realized by hollowing out a part of the insulating layer, it has a shape having a recess. Within the third contact hole 502, the second metal layer 212 and the third metal layer 213 are electrically connected. Specifically, the second wiring 112 on the first insulating layer 201 and the second connection electrode on the second insulating layer 202 are formed by the third metal layer 213 disposed on the second insulating layer 202. 114 are electrically connected.

  The first connection electrode 113 and the second connection electrode 114 are electrically connected to each other by the first connection electrode 311 and the second connection electrode 312 on the flexible printed wiring board 300 and the first anisotropic conductive resin 401. Connected. A region that is not covered with the insulating layer by the first wiring 111, the first connection electrode 113, the second wiring 112, and the second connection electrode 114 is disposed so as to cover the flexible printed wiring board 300. Between the wiring in the region not covered with the insulating layer and the flexible printed wiring board 300 is filled with the second anisotropic conductive resin 402 and is electrically insulated from the outside. In addition, the contact holes 501 and 502 are filled with the second anisotropic conductive resin 402 to maintain insulation. When the electrodes are connected with the anisotropic conductive resin, the anisotropic conductive resin is heated to lower the viscosity and then cured. Here, since the contact hole has a concave shape, when the anisotropic conductive resin is heated, the resin flows into the concave portion. Therefore, the contact hole can be completely filled with resin. At this time, the first anisotropic conductive resin 401 and the second anisotropic conductive resin 402 at the end of the substrate can also be formed. That is, during heating, the first anisotropic conductive resin 401 for pressurizing the electrodes at the same time and electrically connecting the electrodes is formed. The portion of the second anisotropic conductive resin 402 is also formed at the same time as the anisotropic conductive resin having a lowered viscosity protrudes and is cured.

  In the present embodiment, the wiring always has a contact hole for electrically connecting different metal layers, and the contact hole has a concave shape, so that it can be reliably filled with an anisotropic conductive resin. it can. Therefore, it is possible to provide a capacitive transducer having a higher insulating property in a wiring portion straddling a plurality of metal layers.

(Fourth embodiment)
The fourth embodiment is different in that a part of the wirings 111 and 112 is configured by the first metal layer 211. That is, in the present embodiment, a part of the first wiring and a part of the second wiring are formed of the same layer as the electrode layer that forms the first electrode. The rest is the same as the third embodiment.

  FIG. 6 is a schematic diagram for explaining a capacitive transducer according to the fourth embodiment. The present embodiment is different in that the second wiring 112 is once passed through the first metal layer 211 via the fourth contact hole 503. When the first metal layer 211 is formed, part of the second wiring 112 is formed. The second wiring 112 in the first metal layer 211 has a fourth contact hole 503 and a third contact hole 502 at both ends. The fourth contact hole is formed by forming a region where the first insulating layer 201 is not disposed over the first metal layer 211. A second metal layer 212 is stacked in the fourth contact hole 503 and connected to the second wiring 112. The second metal layer 212 stacked in the fourth contact hole is covered with the second insulating layer 202.

  According to the configuration of the present embodiment, most of the first wiring 111 and the second wiring 112 are doubly covered by the first insulating layer 201 and the second insulating layer 202. Insulation can be performed more reliably. Therefore, even if the length of the wiring from the element to the connection electrode is increased, insulation can be reliably performed. As described above, according to the present embodiment, it is possible to provide a capacitive transducer having high insulation even when the length of the wiring between the element and the connection electrode is long.

(Fifth embodiment)
The fifth embodiment is different in that the contact hole is arranged at the center of the connection electrode. That is, in the present embodiment, contact holes for electrically connecting to the lower metal layer are formed in the insulating layer below the portion where the first connection electrode and the second connection electrode are disposed. Then, the first connection electrode is disposed so as to sandwich one contact hole, and the second connection electrode is disposed so as to sandwich the other contact hole. The rest is the same as any one of the first to fourth embodiments.

  FIG. 7 is a schematic diagram illustrating a capacitive transducer according to the fifth embodiment. In the present embodiment, only different points will be described as modifications of the capacitive transducer of FIG. The present embodiment is different from the fifth embodiment in that the connection electrodes 113 and 114 disposed on the second insulating layer 202 are disposed on the third insulating layer 203. The first connection electrode 113 is divided into two regions, and the second contact hole 501 is disposed between the divided connection electrodes 113. The first connection electrode 113 includes a third metal layer 213 formed over the second insulating layer 202, and the third metal layer 213 is connected to the first wiring 111 in the second contact hole 501. Electrically connected.

  Similarly, the second connection electrode 114 is divided into two regions, and the third contact hole 502 is disposed between the divided connection electrodes 114. The second connection electrode 114 includes a third metal layer 213 formed over the second insulating layer 202, and the third metal layer 213 is connected to the second wiring 112 in the third contact hole 502. Electrically connected.

  According to the configuration of the present embodiment, the connection electrodes 113 and 114 on the substrate 100 are fixed by the connection electrodes 311 and 312 on the flexible printed wiring board 300 and the first anisotropic conductive resin 401. Therefore, the connection electrode in which the substrate 100 and the flexible printed circuit board 300 are fixed is divided into right and left with respect to the drawing, and the contact holes 501 and 502 arranged at the center thereof are insulated from the flexible printed circuit board 300. The film 302 is surely covered. Further, when the anisotropic conductive resin is cured, since the left and right sides are covered with the connection electrodes, the resin 402 is more reliably filled in the region sandwiched between the connection electrodes.

  In the present embodiment, it is possible to provide a capacitive transducer having a higher insulating property near the contact hole.

(Sixth embodiment)
The sixth embodiment is different in that the contact hole is arranged closer to the substrate end than the connection electrode. That is, in the present embodiment, contact holes for electrically connecting to the lower metal layer are formed in the insulating layer below the portion where the first connection electrode and the second connection electrode are disposed. One contact hole is disposed closer to the end of the substrate than the first connection electrode, and the other contact hole is disposed closer to the end of the substrate than the second connection electrode. The rest is the same as any one of the first to fifth embodiments.

  FIG. 8 is a schematic diagram illustrating a capacitive transducer according to the sixth embodiment. In the present embodiment, only different points will be described as modifications of the capacitive transducer of FIG. The present embodiment is different from the fifth embodiment in that the connection electrodes 113 and 114 disposed on the second insulating layer 202 are disposed on the third insulating layer 203. The first connection electrode 113 is disposed between the position where the second contact hole 501 is disposed and the position where the element is disposed. The first connection electrode 113 includes a third metal layer 213 formed over the second insulating layer 202, and the third metal layer 213 is connected to the first wiring 111 in the second contact hole 501. Electrically connected.

  Similarly, the second connection electrode 114 is disposed between the position where the third contact hole 502 is disposed and the position where the element is disposed. The second connection electrode 114 includes a third metal layer 213 formed over the second insulating layer 202, and the third metal layer 213 is connected to the second wiring 112 in the third contact hole 502. Electrically connected.

  According to the configuration of the present embodiment, the second insulating film 303 is disposed below the conductive layer 301 of the flexible printed wiring board 300 between the contact holes 501 and 502 and the end of the substrate 100. The second insulating film 303 has a certain thickness, and the distance between the flexible printed wiring board 300 and the board 100 becomes narrow. Therefore, the second insulating film 303 is necessary for the second anisotropic conductive resin 402 disposed in the region. The thickness is thin. Therefore, when the anisotropic conductive resin is cured, the space between the flexible printed wiring board 300 and the substrate 100 can be reliably filled with the second anisotropic conductive resin 402.

  In the present embodiment, it is possible to provide a capacitive transducer having a higher insulating property without substantially increasing the area necessary for connecting the flexible printed wiring board 300 and the board 100.

  In the fifth and sixth embodiments, the configuration of the capacitive transducer has been described as a modification of FIG. 5 described in the third embodiment, but the present invention is not limited to this. It can be used in the same manner for the configurations of other capacitive transducers as well as the configurations of the capacitive transducers described in any of the first, second, and fourth embodiments.

(Seventh embodiment)
The seventh embodiment includes a transducer such as the capacitive transducer described in the first to sixth embodiments, and acquires object information using an acoustic wave including ultrasonic waves. It is a kind of image forming apparatus of an acquisition apparatus.

  FIG. 9 is a schematic diagram illustrating the image forming apparatus of the present embodiment. In FIG. 9, 600 is an image forming apparatus, 601 is a light source, 602 is a measurement target, 603 is a transducer such as a capacitive transducer, 604 is an image information generating apparatus as a processing unit, and 605 is an image display. Reference numeral 701 is an ultrasonic wave, 702 is a reflected ultrasonic wave, 703 is ultrasonic transmission information, and 704 is an ultrasonic reception signal of an electrical signal. Also, 705 is a reproduction image information of transmission / reception, 706 is a light emission instruction signal, 707 is light, 708 is an acoustic wave (ultrasonic wave) generated by irradiation of the light 707, 709 is a photoacoustic wave reception signal, and 710 is a photoacoustic signal Reproduced image information.

  FIG. 9A shows an image forming apparatus that forms an image by transmitting and receiving ultrasonic waves in a transducer such as the capacitive transducer described in the first to sixth embodiments. Hereinafter, ultrasonic measurement using transmitted ultrasonic waves will be described in detail. An ultrasonic wave 701 is output (transmitted) from the capacitive transducer 603 toward the measurement object 602. Ultrasonic waves are reflected on the surface of the measurement object 602 due to the difference in specific acoustic impedance at the interface. The reflected ultrasonic wave 702 is received by the capacitive transducer 603, and for example, information on the magnitude, shape, and time of the received signal is sent to the image information generation device 604 as the ultrasonic reception signal 704. On the other hand, the size, shape, and time information of the transmission ultrasonic waves are stored in the image information generation device 604 as ultrasonic transmission information. The image information generation device 604 generates an image signal of the measurement object 602 based on the ultrasonic reception signal 704 and the ultrasonic transmission information 703 and outputs it as reproduced image information 705. The image display 605 displays the measurement object 602 as an image based on the reproduced image information by ultrasonic transmission / reception.

  Further, the transducer such as the capacitive transducer described in any one of the first to sixth embodiments can be used for reception of ultrasonic waves using the photoacoustic effect, and the image forming apparatus that executes the transducer can be used. Can be applied. The operation of the ultrasonic measurement apparatus of this example will be specifically described with reference to FIG. First, based on the light emission instruction signal 706, light 707 is emitted from the light source 601 to irradiate the measurement object 602 with the light 707. In the measurement object 602, photoacoustic waves (ultrasonic waves) 708 are generated by irradiation with the light 707, and the ultrasonic waves 708 are received by the capacitive transducer 603. Information on the size, shape, and time of the received signal is sent to the image information generating device 604 as a photoacoustic wave received signal 709 converted into an electrical signal. On the other hand, the information (light emission information) on the size, shape, and time of the light 707 generated by the light source 610 is stored in the image information generation device 604 as a photoacoustic signal. The photoacoustic signal image information generation device 604 generates an image signal of the measurement object 602 based on the photoacoustic wave reception signal 709 and the light emission information, and outputs it as reproduced image information 710 using the photoacoustic signal. The image display 605 displays the measurement object 602 as an image based on the reproduced image information 710 based on the photoacoustic signal.

  Further, the image display 605 can also display the measurement object 602 as an image based on two pieces of information: reproduced image information 705 obtained by ultrasonic transmission / reception and reproduced image information 710 obtained by a photoacoustic signal. In this case, since an image can be formed based on a plurality of pieces of received information, an image with a large amount of information can be displayed.

  As shown in the present embodiment, the capacitive transducers described in the first to sixth embodiments are used because high insulation is ensured between the internal electrodes and wiring and the surface. In an image forming apparatus or the like, high safety can be achieved.

  100 .. Substrate, 101... First electrode, 102... Second electrode, 103 .. Spacing, 104 .. Vibration film, 105 .. Supporting part, 111 .. First wiring, 112. 2 wiring 113, first connection electrode 114, second connection electrode 201, 202, insulating layer, 300, flexible substrate, 302, 303, insulating film, 311 ... third Connection electrode, 312... Fourth connection electrode, 401.. Anisotropic conductive resin, 900.

Claims (13)

A capacitive transducer having one or more cells each including a first electrode and a vibration film including a second electrode formed at a distance from the first electrode on a substrate. ,
A first wiring electrically connected to the first electrode; a first connection electrode electrically connected to the first wiring; and a second wiring connected to the second electrode A second connection electrode electrically connected to the second wiring, a third connection electrode disposed opposite to the first connection electrode and the second connection electrode on the substrate, and A flexible substrate having a fourth connection electrode;
The space between the third connection electrode and the fourth connection electrode of the flexible substrate and the first connection electrode and the second connection electrode is narrower than the size of the particles of the anisotropic conductive resin. Are each electrically connected by
The capacitive transducer according to claim 1, wherein the electrode, the wiring, and the connection electrode on the substrate are covered with an insulating layer formed on the substrate and an insulating film of the flexible substrate.   The wiring and the connection electrode on the substrate are filled with an anisotropic conductive resin that performs an insulating function on a region not covered with an insulating layer formed on the substrate. 2. The capacitive transducer according to 1.   The said 1st connection electrode and said 2nd connection electrode on the said board | substrate are comprised by the same layer as the electrode layer which comprises the said 1st electrode, The Claim 1 or 2 characterized by the above-mentioned. Capacitive transducer.   The said 1st connection electrode and said 2nd connection electrode on the said board | substrate are comprised by the same layer as the electrode layer which comprises the said 2nd electrode, The Claim 1 or 2 characterized by the above-mentioned. Capacitive transducer.   The said 1st connection electrode and said 2nd connection electrode on the said board | substrate are comprised by the metal layer formed into a film on the electrode layer which comprises the said 2nd electrode. 3. The capacitive transducer according to 1 or 2.   6. A part of said 1st wiring and a part of said 2nd wiring are comprised by the same layer as the electrode layer which comprises said 1st electrode, Any one of Claim 1 to 5 characterized by the above-mentioned. The capacitive transducer according to claim 1.   Contact holes for electrically connecting to the lower metal layer are respectively formed in the insulating layer under the portion where the first connection electrode and the second connection electrode are disposed, and one contact hole is sandwiched between the contact holes. The first connection electrode is arranged as described above, and the second connection electrode is arranged so as to sandwich the other contact hole. The static electricity according to any one of claims 1 to 6, Capacitive transducer.   Contact holes for electrically connecting to the lower metal layer are respectively formed in the insulating layer below the portion where the first connection electrode and the second connection electrode are disposed, and one contact hole is 7. The device according to claim 1, wherein the first contact electrode is disposed closer to the end of the substrate, and the other contact hole is disposed closer to the end of the substrate than the second connection electrode. 2. The capacitive transducer according to item 1. A transducer having one or more cells each including a first electrode and a second electrode formed on the substrate with the first electrode and the insulating portion being separated from each other,
A wiring electrically connected to the first electrode, a first connection electrode electrically connected to the wiring, a wiring connected to the second electrode, and an electrical connection to the wiring And a flexible substrate having a third connection electrode and a fourth connection electrode disposed to face the first and second connection electrodes on the substrate, respectively,
The space between the third connection electrode and the fourth connection electrode of the flexible substrate and the first connection electrode and the second connection electrode is narrower than the size of the particles of the anisotropic conductive resin. Are each electrically connected by
The transducer, wherein the electrode, the wiring, and the connection electrode on the substrate are covered with an insulating layer formed on the substrate and an insulating film of the flexible substrate. A transducer according to any one of claims 1 to 9, and a processing unit that acquires and processes information on an object using at least an electrical signal output from the transducer,
2. The object information acquiring apparatus according to claim 1, wherein the transducer receives an acoustic wave from an object and outputs the electric signal. Having a light source,
The object information acquiring apparatus according to claim 10, wherein the transducer receives a photoacoustic wave generated by irradiating the object with light oscillated from the light source and converts the photoacoustic wave into an electric signal.   The object information acquiring apparatus according to claim 10, wherein the processing unit is an image information generating apparatus.   The object information acquiring apparatus according to any one of claims 10 to 12, wherein the transducer is the capacitive transducer according to any one of claims 1 to 8.

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