Mounting structure, ultrasonic device, ultrasonic probe, ultrasonic apparatus, electronic apparatus, and manufacturing method of mounting structure

A mounting structure includes a first substrate which has a first surface on which a functional element is provided, a second substrate that has a second surface facing the first surface, a wiring portion that is provided at a position which is different from a position of the functional element on the first surface, has a third surface facing the second surface, and is electrically connected to the functional element, and a conduction portion that is provided on the second surface, protrudes toward the first surface, and is connected to the third surface so as to be electrically connected to the functional element, in which an area of the third surface is larger than an area of a first end section of the wiring portion on the first substrate side in a plan view which is viewed from a thickness direction of the first substrate and the second substrate.

BACKGROUND

1. Technical Field

The present invention relates to a mounting structure, an ultrasonic device, an ultrasonic probe, an ultrasonic apparatus, an electronic apparatus, and a manufacturing method of the mounting structure.

2. Related Art

In a case where an electronic component is mounted on a circuit substrate, there is a mounting method in which a wiring on the circuit substrate side is electrically connected to a wiring on the electronic component side via a bump electrode (for example, refer to JP-A-2007-180166).

JP-A-2007-180166 discloses the electronic component in which an electronic element (functional element) such as an IC chip and a conductive film as a metal wiring connected to the electronic element are formed on a substrate. The conductive film is extracted from the functional element to a surface of a resin protrusion formed at a peripheral edge portion of the substrate. The resin protrusion and the conductive film covering the surface of the resin protrusion form a bump electrode. The circuit substrate is a substrate on which a liquid crystal panel is formed, and an electrode terminal is formed outside a region in which liquid crystal is disposed. The electronic component is mounted on the circuit substrate in a state in which the bump electrode on the electronic component side is brought into contact with the electrode terminal on the circuit substrate side.

However, in the configuration disclosed in JP-A-2007-180166, the electrode terminal is brought into contact with the bump electrode at the peripheral edge portion of the circuit substrate which does not face the functional element. In other words, the circuit substrate and the electronic component are connected to each other at a position separated from the functional element. In this case, a wiring connecting the electrode terminal of the circuit substrate at the peripheral edge portion to the functional element is necessarily formed, and thus this is not suitable for high-density integration of the functional element. In other words, in a case where a plurality of functional elements are provided on a substrate, a wiring configuration for each functional element is complicated, resistance of each wiring increases, or the influence of parasitic capacitance between adjacent wirings increases. In contrast, in a case where wirings are connected to each other in a region in which a functional element is formed, high-density integration of the functional element may be achieved by reducing a size of an electrode terminal.

However, if the size of the electrode terminal is reduced, it is necessary to perform positioning between the circuit substrate and the electronic component with high accuracy during wiring connection. In other words, in a case where positioning accuracy between the substrate and the circuit substrate is not sufficient, there is concern that appropriate wiring connection may not be performed due to positional deviation between the electrode terminal and the bump electrode. As mentioned above, in the configuration of the related art, there is concern that the reliability of electrical connection between substrates in a region in which a functional element is formed may be reduced.

SUMMARY

An advantage of some aspects of the invention is to provide a mounting structure, an ultrasonic device, an ultrasonic probe, an ultrasonic apparatus, an electronic apparatus, and a manufacturing method of the mounting structure as application examples and embodiments capable of improving the reliability of electrical connection between substrates.

A mounting structure according to an application example of the invention includes a first substrate which has a first surface on which a functional element is provided; a second substrate that has a second surface facing the first surface; a wiring portion that is provided at a position which is different from a position of the functional element on the first surface, has a third surface facing the second surface, and is electrically connected to the functional element; and a conduction portion that is provided on the second surface, protrudes toward the first surface, and is connected to the third surface so as to be electrically connected to the functional element, in which an area of the third surface is larger than an area of a first end section of the wiring portion on the first substrate side in a plan view which is viewed from a thickness direction of the first substrate and the second substrate.

In the application example, the functional element and the wiring portion which is electrically connected to the functional element are provided on the first surface of the first substrate. The conduction portion connected to the wiring portion is provided on the second surface of the second substrate. An area of the third surface of the wiring portion is larger than an area of the first end section of the wiring portion on the first substrate side in a plan view in the thickness direction. In this configuration, it is possible to increase the area of the third surface connected to the conduction portion without changing the area of the first end section in the plan view. Therefore, it is possible to increase an allowable amount of positional deviation between the first substrate and the second substrate and thus to improve connection reliability. It is possible to achieve high-density integration of the functional element without changing the area of the first end section in the plan view.

In the mounting structure according to the application example, it is preferable that a second end section of the wiring portion on the second substrate side protrudes along the first surface.

In the application example with this configuration, the second end section of the wiring portion protrudes along the first surface. In this configuration, it is possible to suppress an increase in a sectional area (an area of a section which is parallel to the first surface and the second surface) of the wiring portion on the first end section side while increasing an area of the third surface of the wiring portion. Therefore, it is possible to achieve high-density integration of the functional element and also to improve connection reliability.

In the mounting structure according to the application example, it is preferable that the wiring portion has a side surface ranging between the first end section and the second end section, and the side surface has a depressed surface which is depressed in a direction of becoming distant from the functional element on a side on which the functional element is disposed.

The wiring portion of the application example with this configuration has the depressed surface which is depressed in a direction of becoming distant from the functional element as the side surface on the side on which the functional element is disposed. In other words, when the wiring portion is cut in a plane which passes through positions (central positions) where the wiring portion and the functional element are disposed and which are along the substrate thickness direction, the side surface thereof is curved to be depressed toward the center side of the wiring portion. Consequently, the side surface of the wiring portion can be separated from the functional element compared with a configuration in which the side surface protrudes toward the functional element, or a configuration in which the side surface is linear. Therefore, it is possible to further prevent interference between the functional element and the wiring portion.

In the mounting structure according to the application example, it is preferable that the third surface has a projection protruding toward the second surface side.

In the application example with this configuration, the third surface of the wiring portion has a projection on the second surface side, that is, a projection surface projecting toward the second surface side. An area of the third surface is increased, for example, compared with a case where the third surface is flat. Therefore, since the conduction portion is in close contact with and along the third surface, a connection area can be increased, and thus it is possible to reduce contact resistance (electric resistance).

In the mounting structure according to the application example, it is preferable that the third surface has a depression which is depressed toward the first surface side.

In the application example with this configuration, the third surface of the wiring portion has a depression which is depressed toward the first surface side, that is, a depressed surface depressed toward the first surface side. In this configuration, even if positional deviation of the conduction portion occurs with respect to the third surface during wiring connection, the conduction portion can be moved to a predetermined position such as the deepest portion of the curved surface (for example, a portion closest to the first substrate) along the curved surface. Therefore, it is possible to improve the accuracy of positioning between the first substrate and the second substrate.

In the mounting structure according to the application example, it is preferable that the conduction portion has a protrusion protruding toward the first surface side.

In the application example with this configuration, the conduction portion has a protrusion protruding toward the first surface side, that is, a projection surface projecting toward the first surface side. In this configuration, during wiring connection, at least a part of the protrusion on the conduction portion side is inserted into the depression on the wiring port ion side, and thus the first substrate and the second substrate can be positioned. Therefore, positioning between the first substrate and the second substrate is facilitated. The accuracy of positioning can be improved.

In the mounting structure according to the application example, it is preferable that the depression includes a spherical depression section which is curved at a first curvature, the protrusion includes a spherical projection section which is curved at a second curvature, and the first curvature is equal to or less than the second curvature.

In the application example with this configuration, the depression includes the spherical depression section having the first curvature. The protrusion includes the spherical projection section having the second curvature. The first curvature is equal to or less than the second curvature. In this configuration, the protrusion can be moved along the depression having the curvature which is equal to or less than the curvature of the protrusion. Therefore, even if positional deviation occurs between the wiring portion and the conduction portion as described above, the conduction portion can be moved more reliably along the depression of the wiring portion, and thus positioning accuracy can be improved.

In the mounting structure according to the application example, it is preferable that the depression includes a spherical depression section which is curved at a first curvature, the protrusion includes a spherical projection section which is curved at a second curvature, and the first curvature is more than the second curvature.

In the application example with this configuration, the depression includes the spherical depression section having the first curvature. The protrusion includes the spherical projection section having the second curvature. The first curvature is more than the second curvature. In this configuration, the projection and the depression can be relatively moved according to the curvature of the protrusion so that central positions of the protrusion and the depression in a surface intersecting the substrate thickness direction match each other. Positioning between the first substrate and the second substrate is facilitated. Positioning accuracy can be improved.

In the mounting structure according to the application example, it is preferable that the conduction portion has a fourth surface connected to the third surface, and at least one of the third surface and the fourth surface has a sliding preventing section preventing sliding between the third surface and the fourth surface.

In the application example with this configuration, at least one of the third surface and the fourth surface has a sliding preventing section preventing sliding between the third surface and the fourth surface. In this configuration, sliding between the third surface and the fourth surface can be prevented during wiring connection, and thus it is possible to prevent a reduction in positioning accuracy due to sliding.

In the mounting structure according to the application example, it is preferable that the sliding preventing section has irregularities.

In the application example with this configuration, irregularities are provided as the sliding preventing section. In this configuration, it is possible to prevent a reduction in positioning accuracy due to sliding between the third surface and the fourth surface with a simple configuration in which the irregularities are provided on at least one of the third surface and the fourth surface.

A mounting structure according to an application example includes a first substrate which has a first surface on which a functional element is provided; a second substrate that has a second surface facing the first surface; a wiring portion that is provided at a position which is different from a position of the functional element on the first surface, and is electrically connected to the functional element; and a conduction portion that is provided on the second surface, protrudes toward the first surface, and is connected to the wiring portion so as to be electrically connected to the functional element, in which the wiring portion has a third surface facing the second surface, in which the conduction portion has a fourth surface connected to the third surface, and in which at least one of the third surface and the fourth surface has a sliding preventing section preventing sliding between the third surface and the fourth surface.

In the application example, the functional element and the wiring portion which is electrically connected to the functional element are provided on the first surface of the first substrate. The conduction portion connected to the wiring portion is provided on the second surface of the second substrate. At least one of the third surface of the wiring portion and the fourth surface of the conduction portion connected to each other has the sliding preventing section. In this configuration, sliding between the third surface and the fourth surface can be prevented during wiring connection, and thus it is possible to prevent a reduction in positioning accuracy due to sliding.

Since it is possible to prevent a reduction in positioning accuracy, it is possible to prevent interference between the conduction portion and the functional element due to positional deviation between the first substrate and the second substrate. Since it is possible to prevent a reduction in positioning accuracy, it is possible to achieve high-density integration of the functional element.

In the mounting structure according to the application example, it is preferable that the conduction portion includes a resin section and a conductive film covering the resin section.

In the application example with this configuration, the conduction portion includes the resin section and the conductive film covering the resin section. In this configuration, the conduction portion can be elastically deformed by the resin section and the conductive film. Therefore, it is possible to improve close contact between the conduction portion and the wiring portion and thus to improve connection reliability during wiring connection.

An ultrasonic device according to an application example of the invention includes a first substrate which has a first surface on which a vibrator is provided; a second substrate that has a second surface facing the first surface; a wiring portion that is provided at a position which is different from a position of the vibrator on the first surface, has a third surface facing the second surface, and is electrically connected to the vibrator; and a conduction portion that is provided on the second surface, protrudes toward the first surface, and is connected to the third surface so as to be electrically connected to the vibrator, in which an area of the third surface is larger than an area of a first end section of the wiring portion on the first substrate side in a plan view which is viewed from a thickness direction of the first substrate and the second substrate.

In the application example, the vibrator and the wiring portion which is electrically connected to the vibrator are provided on the first surface of the first substrate. The conduction portion connected to the wiring portion is provided on the second surface of the second substrate. An area of the third surface of the wiring portion is larger than an area of the first end section of the wiring portion on the first substrate side in a plan view in the thickness direction.

In this configuration, in the same manner as in the application example, it is possible to increase an allowable amount of positional deviation between the first substrate and the second substrate and thus to improve connection reliability, compared with a case where the conduction portion is connected to an electrode terminal formed on the first surface of the first substrate.

In the same manner as in the application example, it is possible to achieve high-density integration of the vibrator by reducing an area on the first end section side.

An ultrasonic probe according to an application example of the invention includes a first substrate which has a first surface on which a vibrator is provided; a second substrate that has a second surface facing the first surface; a wiring portion that is provided at a position which is different from a position of the vibrator on the first surface, has a third surface facing the second surface, and is electrically connected to the vibrator; a conduction portion that is provided on the second surface, protrudes toward the first surface, and is connected to the third surface so as to be electrically connected to the vibrator; and a casing that stores the first substrate, the wiring portion, the second substrate, and the conduction portion, in which an area of the third surface is larger than an area of a first end section of the wiring portion on the first substrate side in a plan view which is viewed from a thickness direction of the first substrate and the second substrate.

In the application example, the vibrator and the wiring portion which is electrically connected to the vibrator are provided on the first surface of the first substrate. The conduction portion connected to the wiring portion is provided on the second surface of the second substrate. An area of the third surface of the wiring portion is larger than an area of the first end section of the wiring portion on the first substrate side in a plan view in the thickness direction.

In this configuration, in the same manner as in the application example, it is possible to increase an allowable amount of positional deviation between the first substrate and the second substrate and thus to improve connection reliability, compared with a case where the conduction portion is connected to an electrode terminal formed on the first surface of the first substrate.

In the same manner as in the application example, it is possible to achieve high-density integration of the vibrator by reducing an area on the first end section side.

An ultrasonic apparatus according to an application example of the invention includes a first substrate which has a first surface on which a vibrator is provided; a second substrate that has a second surface facing the first surface; a wiring portion that is provided at a position which is different from a position of the vibrator on the first surface, has a third surface facing the second surface, and is electrically connected to the vibrator; a conduction portion that is provided on the second surface, protrudes toward the first surface, and is connected to the third surface so as to be electrically connected to the vibrator; and a control unit that controls the vibrator, in which an area of the third surface is larger than an area of a first end section of the wiring portion on the first substrate side in a plan view which is viewed from a thickness direction of the first substrate and the second substrate.

In the application example, the vibrator and the wiring portion which is electrically connected to the vibrator are provided on the first surface of the first substrate. The conduction portion connected to the wiring portion is provided on the second surface of the second substrate. An area of the third surface of the wiring portion is larger than an area of the first end section of the wiring portion on the first substrate side in a plan view in the thickness direction.

In this configuration, in the same manner as in the application example, it is possible to increase an allowable amount of positional deviation between the first substrate and the second substrate and thus to improve connection reliability, compared with a case where the conduction portion is connected to an electrode terminal formed on the first surface of the first substrate.

In the same manner as in the application example, it is possible to achieve high-density integration of the vibrator by reducing an area on the first end section side.

An electronic apparatus according to an application example of the invention includes a first substrate which has a first surface on which a functional element is provided; a second substrate that has a second surface facing the first surface; a wiring portion that is provided at a position which is different from a position of the functional element on the first surface, has a third surface facing the second surface, and is electrically connected to the functional element; a conduction portion that is provided on the second surface, protrudes toward the first surface, and is connected to the third surface so as to be electrically connected to the functional element; and a control unit that controls the functional element, in which an area of the third surface is larger than an area of a first end section of the wiring portion on the first substrate side in a plan view which is viewed from a thickness direction of the first substrate and the second substrate.

In the application example, the functional element and the wiring portion which is electrically connected to the functional element are provided on the first surface of the first substrate. The conduction portion connected to the wiring portion is provided on the second surface of the second substrate. An area of the third surface of the wiring portion is larger than an area of the first end section of the wiring portion on the first substrate side in a plan view in the thickness direction.

In this configuration, in the same manner as in the application example, it is possible to increase an allowable amount of positional deviation between the first substrate and the second substrate and thus to improve connection reliability, compared with a case where the conduction portion is connected to an electrode terminal formed on the first surface of the first substrate.

In the same manner as in the application example, it is possible to achieve high-density integration of the functional element by reducing an area on the first end section side.

A manufacturing method of a mounting structure according to an application example includes a first substrate which has a first surface on which a functional element is provided, a second substrate that has a second surface facing the first surface, a wiring portion that is provided at a position which is different from a position of the functional element on the first surface, has a third surface facing the second surface, and is electrically connected to the functional element, and a conduction portion that is provided on the second surface, protrudes toward the first surface, and is connected to the third surface so as to be electrically connected to the functional element, the method including forming the wiring portion in which an area of the third surface is larger than an area of an end section on the first substrate side in a plan view which is viewed from a thickness direction of the first substrate and the second substrate; forming the conduction portion on the second substrate; and connecting the wiring portion to the conduction portion.

In the application example, the functional element and the wiring portion which is electrically connected to the functional element are provided on the first surface of the first substrate. The conduction portion connected to the wiring portion is provided on the second surface of the second substrate. An area of the third surface of the wiring portion is larger than an area of the first end section of the wiring portion on the first substrate side in a plan view in the thickness direction.

In this configuration, in the same manner as in the application example, it is possible to increase an allowable amount of positional deviation between the first substrate and the second substrate and thus to improve connection reliability, compared with a case where the conduction portion is connected to an electrode terminal formed on the first surface of the first substrate.

In the same manner as in the application example, it is possible to achieve high-density integration of the functional element by reducing an area on the first end section side.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

First Embodiment

Hereinafter, a description will be made of an ultrasonic measurement apparatus according to a first embodiment with reference to the drawings.

FIG. 1is a perspective view illustrating a schematic configuration of an ultrasonic measurement apparatus1.FIG. 2is a block diagram illustrating a schematic configuration of the ultrasonic measurement apparatus1.

As illustrated inFIG. 1, the ultrasonic measurement apparatus1includes an ultrasonic probe2, and a control device10which is electrically connected to the ultrasonic probe2via a cable3.

In the ultrasonic measurement apparatus1, the ultrasonic probe2is brought into close contact with a surface of a living body (for example, a human body), and ultrasonic waves are transmitted into the living body from the ultrasonic probe2. Ultrasonic waves reflected at an organ of the living body are received by the ultrasonic probe2, and, for example, an internal tomographic image of the living body is acquired, or a state (for example, a blood flow) of an organ of the living body is measured, on the basis of received signals.

Configuration of Control Device

The control device10corresponds to a control unit, and is configured to include, for example, an operation unit11, a display unit12, a storage unit13, and a calculation unit14, as illustrated inFIG. 2. The control device10may employ, for example, a terminal device such as a tablet terminal, a smart phone, or a personal computer, and may be a dedicated terminal device for operating the ultrasonic probe2.

The operation unit11is a user interface (UI) for a user operating the ultrasonic measurement apparatus1, and may be formed of, for example, a touch panel provided on the display unit12, operation buttons, a keyboard, and a mouse.

The display unit12is formed of, for example, a liquid crystal display, and displays an image.

The storage unit13stores various programs or various pieces of data for controlling the ultrasonic measurement apparatus1.

The calculation unit14is formed of, for example, a calculation circuit such as a central processing unit (CPU) and a storage circuit such as a memory. The calculation unit14reads various programs stored in the storage unit13and executes the programs so as to perform control for processes of generating and outputting a transmission signal for causing the ultrasonic probe2to transmit ultrasonic waves; and to perform control for various processes (for example, setting of a frequency of a reception signal or gain setting) of causing the ultrasonic probe2to receive ultrasonic waves.

Configuration of Ultrasonic Probe

The ultrasonic probe2includes a casing21, an ultrasonic device22stored in the casing21, and a circuit substrate23provided with a driver circuit and the like for controlling the ultrasonic device22(refer toFIG. 2). An ultrasonic sensor24is formed of the ultrasonic device22and the circuit substrate23, and the ultrasonic sensor24forms an ultrasonic module.

Configuration of Casing

As illustrated inFIG. 1, the casing21is formed, for example, in a rectangular box shape in a plan view, and a sensor window21B is provided on one surface (sensor surface21A) which is orthogonal to a thickness direction, and a part of the ultrasonic device22is exposed. A passing hole21C of the cable3is provided at a part of the casing21(a side surface in the example illustrated inFIG. 1), and the cable3is connected to the circuit substrate23inside the casing21through the passing hole21C. A gap between the cable3and the passing hole21C is filled with, for example, a resin material, and thus water resistance is ensured.

In the present embodiment, a configuration example in which the ultrasonic probe2and the control device10are connected to each other via the cable3is described, but, for example, the ultrasonic probe2and the control device10may be connected to each other through wireless communication, and various constituent elements of the control device10may be provided in the ultrasonic probe2.

Configuration of Circuit Substrate

The circuit substrate23is provided with a driver circuit or the like which is bonded to the ultrasonic device22so as to control the ultrasonic device22. As illustrated inFIG. 2, the circuit substrate23includes a selection circuit231, a transmission circuit232, and a reception circuit233.

The selection circuit231switches between connection states such as transmission connection for connecting the ultrasonic device22to the transmission circuit232and reception connection for connecting the ultrasonic device22to the reception circuit233under the control of the control device10.

The transmission circuit232outputs a transmission signal for transmitting ultrasonic waves to the ultrasonic device22via the selection circuit231when a connection state is switched to the transmission connection under the control of the control device10.

The reception circuit233outputs a received signal which is input from the ultrasonic device22via the selection circuit231, to the control device10when a connection state is switched to the reception connection under the control of the control device10. The reception circuit233is configured to include, for example, a low-noise amplification circuit, a voltage controlled alternator, a programmable gain amplifier, a low-pass filter, and an A/D converter, performs various signal processes such as conversion of the received signal into a digital signal, removal of a noise component, and amplification to a desired signal level, and then outputs the processed received signal to the control device10.

Configuration of Ultrasonic Device

FIG. 3is a sectional view of the ultrasonic device22.FIG. 4is a plan view in which an element substrate41of the ultrasonic device22is viewed from a sealing plate42side.FIG. 5is a plan view schematically illustrating an ultrasonic transducer45viewed from a protection film44side.FIG. 3is a sectional view of the ultrasonic device22taken along the line A-A inFIG. 4.

As illustrated inFIG. 3, the ultrasonic device22is configured to include the element substrate41, the sealing plate42, an acoustic matching layer43, and the protection film44. Above all, as illustrated inFIG. 3, the element substrate41and the sealing plate42are electrically connected to each other via a conduction portion421provided on the sealing plate42side.

As illustrated inFIG. 4, the element substrate41is provided with a plurality of ultrasonic transducers45which transmit and receive ultrasonic waves are disposed in a matrix along an X axis and a Y direction intersecting (in the present embodiment, orthogonal to) the X axis. An ultrasonic array UA is formed of the plurality of ultrasonic transducers45.

Configuration of Element Substrate

The element substrate41corresponds to a first substrate, and includes, as illustrated inFIG. 3, a substrate main body portion411, and a vibration film412laminated on the substrate main body portion411. As illustrated inFIG. 4, the element substrate41is provided with piezoelectric elements413, a lower electrode connection line414, a wiring portion415, an upper electrode extraction line416, and bonding portions417on the vibration film412on the sealing plate42side. The ultrasonic transducer45which transmits and receives an ultrasonic wave is formed of a flexible film412A and the piezoelectric element413in a vibration region of the vibration film412among the constituent elements. The element substrate41has an array region Ar1in which the ultrasonic array UA formed of the plurality of ultrasonic transducers45is provided.

Here, in the following description, a surface of the element substrate41facing the sealing plate42will be referred to as a rear surface41A corresponding to a first surface, and a surface opposite to the rear surface41A will be referred to as an operation surface41B. A normal direction to the operation surface41B is substantially the same as the Z direction (a thickness direction of the element substrate41), and a direction from the element substrate41toward the sealing plate42is substantially parallel to the Z direction.

The substrate main body portion411is, for example, a semiconductor substrate such as Si. An opening411A corresponding to each ultrasonic transducer45is provided in an array region Ar1in the substrate main body portion411. The respective openings411A are separated by a wall portion411B (refer toFIG. 3). Each opening411A is closed by the vibration film412provided on the sealing plate42side (−Z side).

The vibration film412is formed of, for example, SiO2, or a laminate of SiO2and ZrO2, and is provided to cover the entire −Z side of the substrate main body portion411. In the vibration film412, a portion closing the opening411A forms the flexible film412A which is elastically deformed. A thickness dimension (thickness) of the vibration film412is a sufficiently small thickness dimension (thickness) relative to the substrate main body portion411. In a case where the substrate main body portion411is made of Si, and the vibration film412is made of SiO2, for example, the substrate main body portion411is subject to oxidation treatment, and thus the vibration film412having a desired thickness dimension (thickness) can be easily formed. In this case, the substrate main body portion411is etched with the vibration film412of SiO2as an etching stopper, and thus the opening411A can be easily formed.

Each piezoelectric element413is provided on the flexible film412A of the vibration film412closing each opening411A. A single ultrasonic transducer45is formed of the flexible film412A and the piezoelectric element413. The piezoelectric element413is formed of a laminate of a lower electrode413A, a piezoelectric film413B, and an upper electrode413C.

The lower electrode413A or the upper electrode413C is configured to include a layer made of one or two or more conductive materials. As such a conductive material, for example, electrode materials such as Au, Al, Cu, Ir, Pt, IrOx, Ti, TiW, and TiOx may be used. In the present embodiment, for example, the lower electrode413A is formed by laminating a TiW layer (50 nm) and a Cu layer (100 nm) in this order on the vibration film412.

The piezoelectric film413B is formed by using, for example, a transition metal oxide having a perovskite structure, more specifically, lead zirconate titanate containing Pb, Ti, and Zr.

A rectangular wave voltage with a predetermined frequency is applied between the lower electrode413A and the upper electrode413C in the ultrasonic transducer45, and thus an ultrasonic wave can be transmitted by causing the flexible film412A located in the opening region of the opening411A to vibrate along the Z direction. If the flexible film412A vibrates due to a reflected ultrasonic wave from a target object, a potential difference occurs in the upper and lower portions of the piezoelectric film413B. Therefore, the received ultrasonic wave can be detected by detecting the potential difference occurring between the lower electrode413A and the upper electrode413C.

In the present embodiment, as illustrated inFIG. 4, among the plurality of ultrasonic transducers45disposed along the X direction and the Y direction, two ultrasonic transducers45arranged in the Y direction form an ultrasonic transducer group45A which is a single transmission/reception channel. In other words, the ultrasonic array UA has a two-dimensional array structure in which the ultrasonic transducer groups45A are disposed along the X direction and the Y direction. That is, the ultrasonic array UA is a two-dimensional array formed by arranging a plurality of transmission/reception channels along the X direction and the Y direction.

The lower electrodes413A of the respective ultrasonic transducers45forming the ultrasonic transducer groups45A are connected to each other via the lower electrode connection line414. The lower electrode connection line414is integrally formed with each lower electrode413A. In other words, the lower electrode connection line414is formed by laminating a TiW layer (50 nm) and a Cu layer (100 nm) in the same manner as, for example, the lower electrode413A. The lower electrode connection line414may be provided separately from the lower electrode413A.

The upper electrode extraction line416is connected to each upper electrode413C of the ultrasonic transducer45. The upper electrode extraction line416is made of a conductive material, and includes a plurality of extraction portions416A disposed along the Y direction, connection portions416B connecting the extraction port ions416A to the upper electrodes413C, and a connection terminal portion416C disposed in a wiring region Ar2.

As illustrated inFIG. 4, for example, each of the extraction portions416A is disposed between the odd-numbered and even-numbered ultrasonic transducer groups45A, when counted along the X direction, and is connected to the upper electrode413C of each ultrasonic transducer group45A via the connection portion416B.

The connection terminal portion416C is formed in the wiring region Ar2of the outer peripheral portion of the element substrate41, and is connected to the extraction portions416A. The connection terminal portion416C is connected to a ground circuit (not illustrated) of the circuit substrate23via a wiring member, and is set to a reference potential (for example, 0 potential). In other words, the upper electrode413C is a common electrode to which a reference potential is applied.

The bonding portion417bonds the element substrate41to the sealing plate42configured as described above. The bonding portions417are disposed at positions along the outer edge of the element substrate41or positions along the ultrasonic transducers45. For example, as illustrated inFIG. 4, the bonding portions417are disposed at positions overlapping the wall portions411B of the rear surface41A along the X direction.

The bonding portion417is formed by using a material which can bond the element substrate41to the sealing plate42, for example, various adhesives or a resin material such as a photosensitive resin material (photoresist). In the present embodiment, the bonding portion417is formed by using a photosensitive resin material. Consequently, the bonding portion417can be formed at a desired position in a desired shape.

Configuration of Wiring Portion

The wiring portion415, which has conductivity, is disposed at a position which is different from that of the ultrasonic transducer45of the rear surface41A, and is electrically connected to the ultrasonic transducer45via the lower electrode connection line414. Specifically, the wiring portion415protrudes toward the sealing plate42from the lower electrode connection line414disposed at a position overlapping the wall portion411B in a plan view viewed from the Z direction, and is electrically connected to the conduction portion421which will be described later. In other words, the lower electrode413A of each ultrasonic transducer45is electrically connected to the conduction portion421via the lower electrode connection line414and the wiring portion415. A single wiring portion415is provided in each of the plurality of ultrasonic transducer groups45A. A mounting structure is configured to include at least the element substrate41, the wiring portion415, the sealing plate42, and the conduction portion421.

The wiring portion415has a first end section415A on the element substrate41side, a second end section415B on the sealing plate42side, a side surface415C, and a contact surface415D (corresponding to a third surface) on the sealing plate42side.

The second end section415B protrudes along the sealing plate42, and has larger dimensions (area) in the X direction and the Y direction than those of the first end section415A. In other words, in the wiring portion415, the second end section415B protrudes in the X direction and the Y direction compared with the first end section415A. At least a part of the second end section415B overlaps the ultrasonic transducer45in the Z direction as illustrated inFIGS. 3 and 4.

The side surface415C is a surface from a basal end section of the wiring portion415on the element substrate41side to the contact surface415D. The side surface415C is a curved surface which is curved in a depressed state toward the center of the wiring portion415in a direction which is orthogonal to the Z direction. In other words, a sectional area of a plane which is parallel to an XY plane of the side surface415C increases, and an increase amount of the sectional area also increases, from the first end section415A toward the second end section415B. In other words, the side surface415C is curved in a direction of becoming distant from the piezoelectric element413. In this configuration, even in a case where the vibration film412vibrates, interference between the wiring portion415(side surface415C) and the piezoelectric element413is reduced.

The contact surface415D has a larger area in a plan view from the Z direction than that of the conduction portion421. In other words, a dimension of the contact surface415D is larger than a dimension of the conduction portion421in the directions (for example, the X direction and the Y direction) which are orthogonal to the Z direction.

The wiring portion415is formed by using, for example, a conductive material such as a metal material, or a resin material containing conductive fillers. For example, the wiring portion415is formed by depositing a metal material on the lower electrode connection line414according to an electroplating method.

Configuration of Sealing Plate

The sealing plate42illustrated inFIGS. 3 to 5, which corresponds to a second substrate, is provided to reinforce the strength of the element substrate41, and is formed of, for example, a semiconductor substrate. The sealing plate42is bonded to the element substrate41via the bonding portions417. A material or a thickness of the sealing plate42influences frequency characteristics of the ultrasonic transducer45, and is thus preferably set on the basis of a center frequency of transmitted and received ultrasonic waves.

The sealing plate42is provided with the conduction portion421and a through electrode422.

Configuration of Conduction Portion

The conduction portion421illustrated inFIGS. 3 to 5is provided on a surface (corresponding to a second surface, and, hereinafter, referred to as an inner surface42A) of the sealing plate42on the element substrate41side, and is in close contact with the wiring portion415provided on the element substrate41so as to be electrically connected thereto. The conduction portion421includes a resin section421A, and a conductive film421B which covers the resin section421A and is electrically connected to the through electrode422.

The resin section421A is provided on the inner surface42A at a position overlapping the wiring portion415as illustrated inFIG. 3, and protrudes from the inner surface42A toward the element substrate41. The resin section421A is made of an elastic resin material, and is formed in a substantially hemisphere shape by thermally melting a resin material disposed on the inner surface42A as will be described later. The resin section421A may be formed in a substantially trapezoidal shape (a state in which corners of a trapezoidal are rounded) according to the kind of resin material, or a temperature condition in thermal melting.

A photosensitive resin material (photoresist) may be used as a material forming the resin section421A. In this case, the resin section421A may be formed in a desired shape at a desired position. As a material forming the resin section421A, not only a photosensitive resin material, but also various elastic resin materials, for example, polyimide resin, acrylic resin, phenol resin, epoxy resin, silicone resin, and modified polyimide resin may be used.

The conductive film421B is made of a conductive material, and coats the resin section421A. The conductive film421B extends to a formation position of the through electrode422along the Y direction, and is connected to the through electrode422. A thickness of the conductive film421B is made sufficiently smaller than a thickness of the resin section421A, and thus the conductive film421B can be deformed according to elastic deformation of the resin section421A.

As a conductive material forming the conductive film421B, Au, Ag, TiW, Cu, Ni, Pd, Al, Cr, Ti, W, NiCr, or a lead-free solder may be used. In the present embodiment, for example, the conductive film421B is formed by laminating a TiW layer (50 nm) and an Au layer (100 nm) in this order from the inner surface42A side.

As illustrated inFIG. 3, a part of the surface421C of the conduction portion421is in contact with the contact surface415D. In other words, the resin section421A and the conductive film421B forming the conduction portion421are formed in, for example, a substantially hemisphere shape in a state in which the sealing plate42is not bonded to the element substrate41. When the sealing plate42is bonded to the element substrate41, the +Z side end section of the conduction portion421is brought into pressure contact with the contact surface415D so that the conduction portion421is elastically deformed, and a connection region Cn (refer toFIG. 5) of the +Z side end section comes into close contact with (electrically connected to) the contact surface415D. Consequently, the conductive film421B is biased toward the wiring portion415side by the restoring force of the elastically deformed resin section421A, and thus it is possible to improve the reliability of electrical connection between the conduction portion421and the wiring portion415.

Configuration of Through Electrode

As illustrated inFIGS. 3 to 5, a pair of through electrodes422are provided at positions with the resin section421A interposed therebetween along the Y direction, and is, for example, a Si through electrode (Through-silicon via: TSV), or a conductive material filling a through hole. A lower electrode wire423is individually formed with respect to each through electrode422on a −Z side surface (hereinafter, referred to as an outer surface42B) of the sealing plate42. The lower electrode wire423is connected to the through electrode422, and is connected to the circuit substrate23via a wiring (not illustrated) formed along the outer surface42B. At least one through electrode422may be formed with respect to a single conduction portion421, and three or more through electrodes may be formed. A position where the through electrode422is disposed is not limited to the illustrated example, and may be formed on, for example, the +X side or −X side of the resin section421A.

Configurations of Acoustic Matching Layer and Protection Film

The acoustic matching layer43is disposed on the element substrate41on the operation surface41B side. In the present embodiment, the acoustic matching layer43fills the opening411A formed on the operation surface41B side.

The protection film44is provided on the element substrate41and the acoustic matching layer43, so as to protect the element substrate41and the acoustic matching layer43. As illustrated inFIG. 1, the protection film44is exposed to the outside from the sensor window21B of the casing21, and is brought into contact with a living body surface during ultrasonic measurement.

The acoustic matching layer43or the protection film44causes an ultrasonic wave transmitted from the ultrasonic transducer45to propagate through a living body which is a measurement target with high efficiency, and causes an ultrasonic wave reflected inside the living body to propagate through the ultrasonic transducer45with high efficiency. Thus, acoustic impedance of the acoustic matching layer43and the protection film44is set to a value similar to acoustic impedance of the living body.

Manufacturing Method of Ultrasonic Device

Hereinafter, a description will be made of a manufacturing method of the above-described ultrasonic device22.

FIG. 6is a flowchart illustrating an example of a manufacturing method of the ultrasonic device22.FIGS. 7 and 8are diagrams schematically illustrating a manufacturing process of the ultrasonic device22.

In order to manufacture the ultrasonic device22, as illustrated inFIG. 6, an element substrate forming process S1, a sealing plate forming process S2, a bonding process S3, and a processing process S4are performed.

Element Substrate Forming Process

In the element substrate forming process S1, first, as illustrated in the first figure ofFIG. 7, the vibration film412, the piezoelectric elements413, the lower electrode connection line414, and the upper electrode extraction line416(not illustrated) are formed on the substrate main body portion411made of, for example, Si (step S11: element portion forming process). In step S11, a film of Zr is formed on a film of SiO2which is formed by performing thermal oxidation treatment on the substrate main body portion411, and thermal oxidation treatment is further performed so as to form a layer of ZrO2and thus to form the vibration film412. The lower electrode413A, the piezoelectric film413B, and the upper electrode413C are formed on the vibration film412, and thus the piezoelectric element413is formed. The lower electrode connection line414is formed when the lower electrode413A is formed, and the upper electrode extraction line416is formed when the upper electrode413C is formed. Specifically, first, an electrode material formed as a film on the vibration film412through, for example, sputtering is patterned, and thus the lower electrode413A and the lower electrode connection line414are formed. Thereafter, the piezoelectric film413B is formed on the lower electrode413A. After the piezoelectric film413B is formed, the upper electrode413C and the upper electrode extraction line416are formed in the same manner as the lower electrode413A and the lower electrode extraction line414.

Next, as illustrated inFIG. 6, the wiring portion415is formed on the lower electrode connection line414(step S12: wiring portion forming process). In step S12, as illustrated in the second figure ofFIG. 7, a mask51which has an opening51A at a forming position of the wiring portion415and is used to form the wiring portion415is formed. This mask51may be formed by using a positive photoresist. As illustrated in the third figure ofFIG. 7, the wiring portion415is formed on the lower electrode connection line414in the opening51A according to, for example, an electroplating method. A surface of the wiring portion415on the −Z side is a projection surface, and protrudes from the opening51A. Next, as illustrated in the fourth figure ofFIG. 7, the flat contact surface415D is formed by polishing the −Z side surface of the wiring portion415, and then the mask51is removed.

Next, as illustrated inFIG. 6, the bonding portions417are formed on the element substrate41(step S13: bonding portion forming process). In step S13, for example, a photosensitive resin layer for forming the bonding portions417is formed on the element substrate41, and is patterned so that the bonding portions417are formed as illustrated in the fifth figure ofFIG. 7.

Sealing Plate Forming Process

Next, as illustrated inFIG. 6, the sealing plate forming process S2is performed. In step S2, the conduction portion421is formed on the inner surface42A side of the sealing plate42provided with the through electrode422(not illustrated). In other words, a resin layer for forming the resin section421A is formed on the inner surface42A and is then patterned. Thereafter, a resin layer remaining on the inner surface42A is heated and melted, and is then solidified, and thus the substantially hemispheric resin section421A is formed. The conductive film421B is formed to cover surfaces of the resin section421A and the through electrode422on the +Z side.

Bonding Process

Next, as illustrated inFIG. 6, a bonding process of bonding the element substrate41and the sealing plate42formed as described above together is performed (step S3). In step S3, as illustrated in the first figure ofFIG. 8, the sealing plate42is disposed on the element substrate41. In this case, relative positions between the element substrate41and the sealing plate42are adjusted. In other words, positioning is performed so that the conduction portion421overlaps the corresponding wiring portion415.

After the positioning is performed, as illustrated in the second figure ofFIG. 8, at least one of the element substrate41and the sealing plate42is pressed in a direction in which the element substrate41and the sealing plate42come close to each other. Consequently, the conduction portion421is elastically deformed so as to come into close contact with the wiring portion415. In this state, the element substrate41and the sealing plate42are heated (for example, for an hour at 200° C.). Consequently, the bonding portion417is melted, and is then solidified again, and thus the element substrate41and the sealing plate42are bonded to each other.

Processing Process

Next, as illustrated inFIG. 6, a processing process of processing the element substrate41and the sealing plate42is performed (step S4). In step S4, as illustrated in the third figure ofFIG. 8, a thickness of the substrate main body portion411of the element substrate41is adjusted, and then the openings411A are formed. A wiring including the lower electrode wires423is formed on the outer surface42B of the sealing plate42. A wiring on the outer surface42B side of the sealing plate42may be formed in advance. Thereafter, as illustrated inFIG. 3, the openings411A are filled with the acoustic matching layer43, and then the protection film44is formed. In the above-described way, the ultrasonic device22is manufactured.

Operations and Effects of First Embodiment

In the present embodiment, the piezoelectric element413and the wiring portion415are provided on the rear surface41A of the element substrate41. The conduction portion421connected to the wiring portion415is provided on the inner surface42A of the sealing plate42. In the wiring portion415, an area of the contact surface415D is larger than an area of the first end section415A in a plan view viewed from the Z direction. In this configuration, it is possible to increase a connectable area of the conduction portion421without changing a dimension of the wiring portion415on the rear surface41A. Therefore, an allowable amount of a positional deviation between the element substrate41and the sealing plate42can be increased. In other words, in the bonding process in step S3, alignment between the element substrate41and the sealing plate42is performed. Even if a position of the conduction portion421is slightly deviated with respect to the wiring portion415at this time, the wiring portion415can be electrically connected to the conduction portion421as long as the deviation is within a range of the allowable amount, and thus it is possible to improve connection reliability.

It is possible to achieve high-density integration of the piezoelectric element413. For example, in a case where the conduction portion421is connected to an electrode terminal formed on the rear surface41A, if a dimension of the electrode terminal is made large in order to similarly increase connection reliability, a gap between the piezoelectric elements413is required to be increased. In other words, it is difficult to make high-density integration of the piezoelectric element413and improvement of connection reliability compatible. In contrast, in the present embodiment, it is possible to increase an area of the contact surface415D without changing a dimension of the wiring portion415on the rear surface41A. Therefore, the ultrasonic device22of the present embodiment can make high-density integration of the piezoelectric element413and improvement of connection reliability compatible.

For example, in a case where the conduction portion421is connected to the electrode terminal formed on the rear surface41A, it is possible to achieve high-density integration of the piezoelectric element413by reducing an area of the electrode terminal. However, if positioning accuracy is low in a case where the area of the electrode terminal is reduced, there is a problem in that there is concern about interference between the conduction portion421and the piezoelectric element413. In relation to this problem, the conduction portion421is connected to the wiring portion415protruding toward the sealing plate42side, and thus it is possible to prevent interference between the conduction portion421and the piezoelectric element413.

The second end section415B of the wiring portion415protrudes along the XY plane. In this configuration, it is possible to more reliably suppress an increase of an area of the first end section415A while increasing an area of the contact surface415D in a plan view. Therefore, it is possible to more reliably realize high-density integration and connection reliability of a functional element.

In the wiring portion415, the side surface415C on the side on which the piezoelectric element413is disposed is a depressed surface. In other words, when the wiring portion415is cut in a YZ plane which passes through positions (central positions) where the piezoelectric element413and the wiring portion415are disposed and which are along the Z direction, the side surface415C thereof is curved to be depressed toward the center side of the wiring portion415. Consequently, the side surface415C of the wiring portion415can be separated from the piezoelectric element413compared with a configuration in which the side surface415C protrudes toward the piezoelectric element413, or a configuration in which the side surface415C is linear. Therefore, it is possible to further prevent interference between the piezoelectric element413and the wiring portion415.

The second end section415B of the wiring portion415protrudes so as to project upward (−Z side) of the ultrasonic transducer45. In other words, apart of the surface of the ultrasonic transducer45on the −Z side is covered with the second end section415B. Consequently, in the bonding process in step S3, even in a case where relative positions between the element substrate41and the sealing plate42are deviated, and thus the conduction portion421is deviated toward the ultrasonic transducer45side, it is possible to prevent interference between the wiring portion415and the ultrasonic transducer45.

A single wiring portion415is provided with respect to two ultrasonic transducers45forming the ultrasonic transducer group45A. In other words, a single wiring portion415is provided with respect to two piezoelectric elements413arranged along the Y direction. In this configuration, the number of wiring portions415can be reduced, and thus a configuration can be simplified. It is possible to increase an arrangement interval between the wiring portions415in the Y direction, and thus to prevent the second end sections415B of the adjacent wiring portions415from contact with each other.

Modification Example of First Embodiment

FIGS. 9 and 10are sectional views schematically illustrating an ultrasonic device according to a modification example of the first embodiment.

In the first embodiment, the side surface of the wiring portion415is a depressed surface, and is curved so that an area of the section which is parallel to the XY plane increases toward the sealing plate42side from the element substrate41.

In contrast, as illustrated inFIG. 9, a wiring portion418may be formed so that a section thereof which is parallel to the YZ plane has a substantially T shape. In other words, the wiring portion418has a rising section which rises along the Z direction on the element substrate41, and a protrusion section which protrudes toward the piezoelectric element413on a −Z side of the rising section.

As illustrated inFIG. 10, a wiring portion419may be formed in a tapered outer shape in which an area of a section which is parallel to the XY plane increases toward the sealing plate42from the element substrate41.

Second Embodiment

Next, a description will be made of a second embodiment.

The contact surface415D of the wiring portion415of the first embodiment is formed to be substantially flat. In contrast, a wiring portion of the second embodiment is different from that of the first embodiment in that a contact surface of the wiring portion has a projection.

In the following description, the same constituent elements as those in the first embodiment are given the same reference numerals, and description thereof will be omitted or will be made briefly.

FIG. 11is a sectional view schematically illustrating an ultrasonic device according to the second embodiment.

As illustrated inFIG. 11, a contact surface (third surface)461of a wiring portion46has a projection protruding toward the inner surface (second surface)42A side of the sealing plate42. In other words, an end section of the wiring portion46on the inner surface (second surface)42A side of the sealing plate42corresponds to a projection.

The conduction portion421is elastically deformed along the contact surface461in the same manner as in the first embodiment. Consequently, the wiring portion46comes into close contact with the conduction portion421.

The wiring portion46may be formed in the substantially same manner as, for example, the wiring portion415of the first embodiment, and only step S12is different. In other words, in the first embodiment, in step S12, the wiring portion46is formed in the opening51A of the mask51formed on the element substrate41, and then the flat contact surface415D is formed in the wiring portion46through polishing. In contrast, in the present embodiment, the wiring portion46is formed in the opening51A of the mask51, and then the mask is removed without polishing the surface of the wiring portion46on the −Z side.

Operations and Effects of Second Embodiment

The contact surface (third surface)461of the wiring portion46has the projection protruding toward the inner surface (second surface)42A of the sealing plate42. In this case, it is possible to increase an area of the contact surface461compared with, for example, a case where the contact surface461is flat. Therefore, since the conduction portion421is in close contact with and along the contact surface461, a connection area between the conduction portion421and the contact surface461can be increased, and thus it is possible to reduce contact resistance (electric resistance).

In the present embodiment, the conduction portion421is configured to be elastically deformed along the contact surface461and thus in close contact therewith. In contrast, a conduction portion may have a depression along the contact surface461. Also in this case, the conduction portion421can be made in close contact with the contact surface461, and a connection area therebetween can also be increased.

Third Embodiment

Next, a third embodiment will be described with reference to the drawings.

The contact surface415D of the wiring portion415of the first embodiment is formed to be substantially flat. In contrast, a wiring portion of the third embodiment is different from that of the first embodiment in that a contact surface has a depression.

In the following description, the same constituent elements as those in the first embodiment are given the same reference numerals, and description thereof will be omitted or will be made briefly.

FIG. 12is a sectional view schematically illustrating an ultrasonic device according to a third embodiment.FIG. 13is a diagram schematically illustrating the ultrasonic device in a bonding process.

As illustrated inFIG. 12, a contact surface (third surface)471of a wiring portion47has a depression curved to be depressed toward the rear surface (first surface)41A side of the element substrate41. In other words, an end section of the wiring portion47on the sealing plate42side corresponds to a depression and a spherical depression section. The contact surface471is curved most toward the rear surface (first surface)41A side of the element substrate41at the center thereof in the X direction and the Y direction. In other words, a distance between the contact surface471and the rear surface (first surface)41A of the element substrate41is shortest at the center of the contact surface471. As illustrated inFIG. 13, the curvature (first curvature) of the contact surface471is equal to or less than the curvature (second curvature) of the surface421C of the conduction portion421before being elastically deformed. In the present embodiment, the first curvature of the contact surface471is less than the second curvature of the surface421C of the conduction portion421.

The conduction portion421corresponds to a spherical projection section having the surface421C which is spherically curved with the second curvature. The conduction portion421is elastically deformed along the contact surface471in the same manner as in the first embodiment. Consequently, the wiring portion47comes into close contact with the conduction portion421.

In the present embodiment, positional deviation between the element substrate41and the sealing plate42can be adjusted in the bonding process in step S3. In other words, in the bonding process, as illustrated inFIG. 13, there is a case where the accuracy of positioning between the element substrate41and the sealing plate42is not sufficient, and a central position C1of the wiring portion47is deviated with respect to a central position C2of the conduction portion421. In the present embodiment, even in a case where deviation occurs between the central positions C1and C2, the conduction portion421is moved along the curved contact surface471in a direction in which the central positions C1and C2match each other.

Operations and Effects of Third Embodiment

The contact surface (third surface)471of the wiring portion47has the depression curved to be depressed toward the rear surface (first surface)41A side of the element substrate41. In this configuration, even if positional deviation of the conduction portion421occurs with respect to the contact surface471during wiring connection, the wiring portion47and the conduction portion421can be relatively moved along the curve of the contact surface471. In other words, the wiring portion47and the conduction portion421can be relatively moved in a direction in which the central positions C1and C2of the wiring portion47and the conduction portion421match each other. Therefore, it is possible to increase the accuracy of positioning between the element substrate41and the sealing plate42.

The conduction portion421has the projecting curved surface which is a protrusion protruding toward the rear surface (first surface)41A of the element substrate41. In this configuration, during wiring connection, the conduction portion421is inserted into the contact surface471which is a depressed surface, and thus the element substrate41and the sealing plate42can be positioned. Therefore, it becomes easier to position the element substrate41and the sealing plate42, and it is possible to improve the accuracy of positioning.

Here, the curvature of the contact surface471is equal to or less than the curvature of the surface421C of the conduction portion421. In this configuration, the conduction portion421can be more reliably moved along the contact surface471.

Fourth Embodiment

Next, a fourth embodiment will be described with reference to the drawings.

The contact surface415D of the wiring portion415of the first embodiment is formed to be substantially flat. In contrast, a wiring portion of the fourth embodiment is different from that of the first embodiment in that a contact surface has a depression which is depressed toward the element substrate side. In the third embodiment, the curvature of the wiring portion is equal to or less than the curvature of the conduction portion. In contrast, in the fourth embodiment, there is a difference in that the curvature of the wiring portion is less than the curvature of the conduction portion.

In the following description, the same constituent elements as those in the first embodiment are given the same reference numerals, and description thereof will be omitted or will be made briefly.

FIG. 14is a sectional view schematically illustrating an ultrasonic device according to the fourth embodiment.

In a wiring portion48illustrated inFIG. 14, a dimension thereof in the X direction and the Y direction increases toward the sealing plate42side from the element substrate41side. The wiring portion48has a contact surface481curved to be depressed toward the element substrate41side. The contact surface481is a depressed and curved surface which is substantially hemispherical. In other words, an end section of the wiring portion48on the sealing plate42side corresponds to a spherical depression section. The contact surface481is curved most toward the element substrate41side at the center thereof in the X direction and the Y direction. As illustrated inFIG. 14, the curvature (first curvature) of the contact surface481is larger than the curvature (second curvature) of the conduction portion421before being elastically deformed.

The conduction portion421is elastically deformed along the contact surface481in the same manner as in the first embodiment. Consequently, the wiring portion48comes into close contact with the conduction portion421.

In the fourth embodiment, an end edge (that is, an outer circumferential edge of the contact surface481when viewed from the Z direction)482of the contact surface481on the −Z side penetrates through the conductive film421B of the conduction portion421and reaches the resin section421A.

Operations and Effects of Fourth Embodiment

As described above, in the bonding process of bonding the element substrate41to the sealing plate42, the wiring portion48comes into close contact with the conduction portion421through positioning between the element substrate41and the sealing plate42. In this case, it is easy to align locations (XY locations) of a central position C3of the wiring portion48and a central position C2of the conduction portion421in the X direction and the Y direction with each other. In other words, there is a case where XY locations of the central positions C2and C3are deviated with respect to each other before the wiring portion48is brought into close contact with the conduction portion421. Also in this case, the conduction portion421has the curvature more than that of the contact surface481, and is thus easily moved along the contact surface481in a direction in which the XY locations of the central positions C2and C3match each other. It is possible to easily perform positioning between the element substrate41and the sealing plate42with high accuracy.

Here, the bonding portion417is overheated and melted in a state in which the element substrate41and the sealing plate42come into pressure contact with each other through positioning. At this time, if positional deviation occurs between the element substrate41and the sealing plate42, the accuracy of positioning is reduced. In contrast, the end edge482of the contact surface481penetrates through the conductive film421B and reaches the resin section421A. Consequently, in the bonding process, it is possible to reduce the occurrence of positional deviation between the element substrate41and the sealing plate42and thus to prevent a reduction in the positioning accuracy. The end edge482functions as a sliding preventing section which prevents sliding between the wiring portion48and the conduction portion421.

Fifth Embodiment

Next, a fifth embodiment will be described with reference to the drawings.

The contact surface415D of the wiring portion415of the first embodiment is formed to be substantially flat. In contrast, there is a difference from the first embodiment in that irregularities as a sliding preventing section are formed on at least one of a wiring portion and a conduction portion of the fifth embodiment.

In the following description, the same constituent elements as those in the first embodiment are given the same reference numerals, and description thereof will be omitted or will be made briefly.

FIG. 15is a sectional view schematically illustrating an ultrasonic device according to the fifth embodiment.

As illustrated inFIG. 15, in a wiring portion49, a plurality of irregularities492are formed on a contact surface491(corresponding to a fourth surface) connected to a conduction portion427. InFIG. 15, the irregularities492are formed on the substantially entire contact surface491, but may be formed on a part of the contact surface491, for example, a central portion in the X direction and the Y direction. The irregularities492are a sliding preventing section preventing sliding between the wiring portion49and the conduction portion427. The irregularities492may be formed on the contact surface491according to, for example, a pulse plating method. The irregularities492may be formed by patterning the contact surface491and processing the contact surface491through wet etching.

The conduction portion427has a resin section427A and a conductive film427B, and a plurality of irregularities427C are formed at a part thereof including an end section on the +Z side. The irregularities427C is a sliding preventing section preventing sliding between the wiring portion49and the conduction portion427. The irregularities427C of the conduction portion427have shapes corresponding to the irregularities492of the wiring portion49side. In other words, the conduction portion427substantially matches the wiring portion49in terms of a depth of a depression, a height of a projection, or a formation pitch of the irregularities.

The conduction portion427is elastically deformed along the contact surface491in the same manner as in the first embodiment. At this time, the wiring portion49and the conduction portion427come into close contact with each other in a state in which the irregularities427C and492of the conduction portion427and the wiring portion49are fitted to each other.

Operations and Effects of Fifth Embodiment

The wiring portion49and the conduction portion427are provided with the irregularities. In this configuration, sliding between the wiring portion49and the conduction portion427can be prevented during wiring connection, and thus it is possible to prevent a reduction in positioning accuracy due to sliding. It is possible to prevent a reduction in positioning accuracy with a simple configuration in which the wiring portion49and the conduction portion427having irregularities comes into close contact with each other.

The conduction portion427has the irregularities427C along the irregularities492of the wiring portion49side, the conduction portion427can be elastically deformed, and comes into close contact with the wiring portion49in a state in which the irregularities427C are fitted to the irregularities492. In this configuration, it is possible to more reliably prevent sliding between the wiring portion49and the conduction portion427due to an anchor effect.

Modification Examples

The invention is not limited to the above-described embodiments, and configurations obtained through modifications, alterations, and combinations of the respective embodiments as appropriate within the scope capable of achieving the object of the invention are included in the invention.

For example, in the fourth embodiment, the wiring portion48is configured to have a larger area on the sealing plate42side than on the element substrate41side, but is not limited thereto, and areas of the wiring portion are substantially the same from the element substrate41side to the sealing plate42side.

FIG. 16is a sectional view schematically illustrating an ultrasonic device according to a modification example of the fourth embodiment.

As illustrated inFIG. 16, in a wiring portion60, sectional shapes (sectional areas) which are parallel to the X direction and the Y direction are substantially the same as each other along the Z direction. The wiring portion60has a contact surface601curved to be depressed toward the element substrate41side. The contact surface601is a depressed and curved surface which is substantially hemispherical. The curvature of the contact surface601is larger than the curvature of the conduction portion421before being deformed. The contact surface601is formed by processing an end section of the wiring portion60on the −Z side through wet etching or the like. Step difference or depressions corresponding to the contact surface601may be formed on a metal base layer which is formed in advance on the +Z side of the wiring portion60, and the wiring portion60may be formed on the metal base layer according to an electroplating method.

An end edge602of the contact surface601penetrates through the conductive film421B of the conduction portion421and reaches the resin section421A. The end edge602functions as a sliding preventing section.

Also in this configuration, in the same manner as in the fourth embodiment, the conduction portion421is easily moved along the contact surface601in a direction in which the XY locations of the central positions match each other, and it is possible to easily perform positioning between the element substrate41and the sealing plate42with high accuracy.

In the fourth embodiment and the modification example, a description has been made of an example of a configuration in which the end edge of the wiring portion having the depression penetrates through the conductive film of the conduction portion, but this is only an example. For example, the conduction portion may be elastically deformed along the contact surface of the wiring portion in a state in which the end edge of the wiring portion does not penetrate through the conductive film.

In the fifth embodiment, the wiring portion49is configured to have a larger area on the sealing plate42side than on the element substrate41side, but is not limited thereto, and areas of the wiring portion are substantially the same from the element substrate41side to the sealing plate42side.

FIG. 17is a sectional view schematically illustrating an ultrasonic device according to a modification example of the fifth embodiment.

As illustrated inFIG. 17, in a wiring portion61, sectional shapes (sectional areas) which are parallel to the X direction and the Y direction are substantially the same as each other along the Z direction. The wiring portion61has a contact surface611provided with a plurality of irregularities612. InFIG. 17, the irregularities612are formed on the substantially entire contact surface611, but may be formed on apart of the contact surface611, for example, a central portion in the X direction and the Y direction. The conduction portion427is elastically deformed along the contact surface611in the same manner as in the first embodiment. At this time, the wiring portion61and the conduction portion427come into close contact with each other in a state in which the irregularities427C and612of the conduction portion427and the wiring portion61are fitted to each other. Consequently, it is possible to more reliably prevent sliding between the wiring portion61and the conduction portion427.

FIG. 18is a sectional view schematically illustrating an ultrasonic device according to a modification example of the fifth embodiment.

As illustrated inFIG. 18, the wiring portion61and the conduction portion427have different dimensions of irregularities. In an example illustrated inFIG. 18, sizes of the irregularities427C of the conduction portion427, that is, depths of depressions, heights of projections, and a pitch of the irregularities are smaller than those of the irregularities612of the wiring portion61. Also in this configuration, at least a part of the conduction portion427is elastically deformed along the irregularities612of the wiring portion61. Consequently, it is possible to more reliably prevent sliding between the wiring portion61and the conduction portion427.

In the fifth embodiment, irregularities are formed in both of the wiring portion and the conduction portion as sliding preventing sections, but this is only an example, and sliding preventing sections may be formed in at least one of the wiring portion and the conduction portion.

In the fifth embodiment, the wiring portion is provided with irregularities as a sliding preventing section, but is not limited thereto, and any configuration may be employed as long as sliding between the wiring portion and the conduction portion can be prevented.

FIG. 19is a sectional view illustrating a modification example of the ultrasonic device. As illustrated inFIG. 19, a wiring portion62has a plurality of protrusions622protruding toward the −Z side from a contact surface621. The protrusions622penetrate through the conductive film427B of the conduction portion427, and reach the resin section427A. Consequently, it is possible to more reliably prevent sliding between the wiring portion62and the conduction portion427.

In the second to fourth embodiments, a description has been made of an example of a configuration in which the wiring portion and the conduction portion do not have sliding preventing sections, but this is only an example, and at least one of the wiring portion and the conduction portion may have sliding preventing sections.

For example, in the configuration of the second embodiment, irregularities are formed on the contact surface of the wiring portion, and thus it is possible to increase a surface area of the contact surface and thus to further reduce contact resistance.

For example, in the configurations of the third and fourth embodiments, a rough surface as a sliding preventing section may be formed in at least one of the wiring portion and the conduction portion. Consequently, it is possible to prevent sliding between the wiring portion and the conduction portion in a state in which the element substrate and the sealing plate are brought into pressure contact with each other.

In the above-described embodiments, a description has been made of an example of a configuration in which a section of the wiring portion along the XY plane is substantially circular, but this is only an example. For example, the section may have various polygonal shapes such as a rectangular shape.

In the above-described respective embodiments, a configuration has been exemplified in which the second end section of the wiring portion extend sections not only to ±Y sides on which the piezoelectric elements413are disposed but also to ±X sides on which the piezoelectric elements413are not disposed, with respect to the wiring portion. However, the invention is not limited thereto, and, for example, the second end section may extend section only to ±Y sides on which the piezoelectric elements413are disposed.

In the above-described embodiments, the wiring portion may be configured to include a coating section which coats the wiring portion. The coating section is formed by using a material such as Au having a relatively high electric conductivity, and thus it is possible to reduce contact resistance between the wiring portion and the conduction portion. In a case where a conductive film and a coating section of the conduction portion are formed by using Au, it is possible to improve connection reliability through diffusion bonding between Au layers.

In the above-described embodiments, the wiring portion on the element substrate41side is made of a conductive material such as metal. The conduction portion of the sealing plate42is configured to include the resin section and the metal film and to be able to be elastically deformed. However, the invention is not limited thereto, and, for example, the conduction portion may also be made of a conductive material such as metal. In a case where the conduction portion does not include an elastic material layer such as a resin section, the conduction portion preferably has an outer shape along a surface of the wiring portion so as to be able to be in close contact with the wiring portion. The wiring portion and the conduction portion may be configured to include resin sections and metal films and thus to be able to be elastically deformed.

In the above-described embodiments, the ultrasonic transducer group45A formed of two ultrasonic transducers45is used as a single transmission/reception channel, but the ultrasonic transducer group45A may be formed by connecting the lower electrodes413A of three or more ultrasonic transducers45to each other. There may be a configuration in which the lower electrodes413A of the respective ultrasonic transducers45are separate from each other, and thus each of the ultrasonic transducers45is individually driven. In this case, each ultrasonic transducer45may function as a single transmission/reception channel.

In the above-described embodiment, a description has been made of an example of the ultrasonic device22having a two-dimensional array structure in which the ultrasonic transducer groups45A each functioning as a single transmission/reception channel are disposed in a matrix in the array region Ar1of the element substrate41, but this is only an example. For example, the ultrasonic device may have a one-dimensional array structure in which a plurality of transmission/reception channels are disposed along one direction. For example, the ultrasonic transducer group45A may be formed of a plurality of ultrasonic transducers45disposed along the X direction, and a plurality of ultrasonic transducer groups45A are disposed in the Y direction so as to form the ultrasonic array UA having a one-dimensional array structure.

In the above-described embodiments, a description has been made of an example of a configuration in which the ultrasonic transducer45is formed of the vibration film412and the piezoelectric element413formed on the vibration film412, but this is only an example. For example, the ultrasonic transducer45may be configured to include a flexible film, a first electrode provided on the flexible film, and a second electrode provided at a position opposing the first electrode in a sealing plate. The first electrode and the second electrode form an electrostatic actuator as a vibrator. In this configuration, an ultrasonic wave can be transmitted by driving the electrostatic actuator, and an ultrasonic wave can be detected by detecting electrostatic capacitance between the electrodes.

In the above-described embodiments, an ultrasonic apparatus which measures an organ of a living body has been described as an example of an electronic apparatus, but the invention is not limited thereto. For example, the configurations of the above-described embodiments and respective modification examples may be applied to a measurement apparatus which measures various structural bodies, and detects a defect of a structural body or inspects aging thereof. This is also the same for a measurement apparatus which measures, for example, a semiconductor package or a wafer, and detects a defect of such a measurement target.

In the above-described embodiments, a description has been made of an example of a configuration in which the ultrasonic transducer is provided on the element substrate, but the invention is not limited thereto. For example, the configurations of the embodiments and respective modification examples may be applied to a mounting structure including a first substrate provided with an electronic component such as a semiconductor IC, that is, an functional element, and a second substrate electrically connected to the first substrate, or an image display device or an image forming device in which the mounting structure is provided in a casing. In other words, a wiring portion which is provided on the first substrate and is connected to the electronic component and a conduction portion which is provided on the second substrate and is connected to the wiring portion are connected to each other further toward the second substrate side than the electronic component, and thus it is possible to prevent interference between the functional element and the conduction portion and thus to appropriately and easily perform wiring connection between the first substrate and the second substrate.

A specific structure when the invention is implemented may be configured as appropriate by combining the respective embodiments and modification examples within the scope of being capable of achieving the object of the invention, and may be changed to other structures as appropriate.

The entire disclosure of Japanese Patent Application No. 2016-161046 filed Aug. 19, 2016 is expressly incorporated by reference herein.