Detection Equipment

Abstract

Provided is a detection device having a highly reliable ultrasonic conversion element with low cost. The detection device comprises a laminated body and a frame layer that is laminated on at least one of a first surface and second surface of the laminated body, the second surface being positioned on the opposite side of the first surface. The laminated body comprises a flexible substrate, a circuit layer including a plurality of first electrodes and laminated on the flexible substrate, and a piezoelectric layer laminated on the circuit layer. One ultrasonic conversion element comprises at least one first electrode contacting the piezoelectric layer and at least one second electrode contacting the piezoelectric layer. The frame layer has a cavity at a position overlapping with the first electrode in a plan view.

Description

[Technical field]

[0001] The present disclosure relates to an ultrasonic transducer that utilizes ultrasonic waves and a detection device using the same. [Background technology]

[0002] Ultrasonic transducers are known (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2015 / 089453 [Patent Document 2] US Patent Application Publication No. 2015 / 0165479 Summary of the Invention [Problem to be solved by the invention]

[0004] The ultrasonic transducer requires a cavity in contact with the piezoelectric layer to be formed in the anchor structure or a substrate such as glass or silicon. If a cavity is provided in the anchor structure, the bonding surface where the piezoelectric layer and the anchor structure are bonded will vibrate, which may result in insufficient strength. In addition, it may be costly to manufacture the cavity by back surface etching of the back surface of the substrate.

[0005] An object of the present disclosure is to provide a detection device having an ultrasonic transducer element that is low cost and highly reliable. [Means for solving the problem]

[0006] A detection device of one embodiment of the present disclosure is a detection device including a plurality of ultrasonic conversion elements that transmit and receive ultrasonic waves, and includes a flexible substrate, a circuit layer including a plurality of first electrodes and at least one second electrode and laminated on the flexible substrate, and a piezoelectric layer laminated on the circuit layer, and a frame layer laminated on at least one of a first surface and a second surface opposite the first surface of the laminate, wherein one of the ultrasonic conversion elements includes at least one of the first electrodes in contact with the piezoelectric layer and at least one of the second electrodes in contact with the piezoelectric layer, and the frame layer has a cavity at a position overlapping with the first electrode in a planar view. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view showing a schematic configuration of a detection device including an ultrasonic element according to a first embodiment. [Diagram 2] FIG. 2 is a block diagram showing an example of the configuration of the detection device according to the first embodiment. [Diagram 3] FIG. 3 is a schematic diagram showing a schematic cross-sectional configuration of the detection device of the first embodiment. [Figure 4] FIG. 4 is a schematic diagram showing the relationship between the detection device and the object to be detected in the space above the detection area. [Diagram 5] FIG. 5 is a circuit diagram showing one of the detection regions of the first embodiment. [Figure 6] FIG. 6 is a plan view showing the detection region of the first embodiment. [Figure 7] FIG. 7 is a timing chart showing the operation of one ultrasonic conversion element in the first embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing the detection region and the frame region of the first embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing a detection region of the second embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing a detection region of the third embodiment. [Figure 11] FIG. 11 is a cross-sectional view showing a detection region of the fourth embodiment. [Figure 12]FIG. 12 is a cross-sectional view showing a detection region of the fifth embodiment. [Figure 13] FIG. 13 is a circuit diagram showing one of the multiple detection regions of the fifth embodiment. [Figure 14] FIG. 14 is a cross-sectional view showing a detection region of the sixth embodiment. [Figure 15] FIG. 15 is a plan view showing the first electrode and the second electrode of the sixth embodiment. [Figure 16] FIG. 16 is a plan view showing a first electrode and a second electrode according to a first modification of the sixth embodiment. [Figure 17] FIG. 17 is a plan view showing a first electrode and a second electrode according to the second modification of the sixth embodiment. [Figure 18] FIG. 18 is a plan view showing a first electrode and a second electrode according to a third modification of the sixth embodiment. [Figure 19] FIG. 19 is a plan view showing a first electrode and a second electrode according to the fourth modification of the sixth embodiment. [Figure 20] FIG. 20 is a plan view showing the detection region of the seventh embodiment. [Figure 21] FIG. 21 is a cross-sectional view showing a detection region of the seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The form (embodiment) for carrying out the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited by the contents described in the following embodiment. In addition, the components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the components described below can be appropriately combined. In addition, the disclosure is merely an example, and those that a person skilled in the art can easily imagine appropriate modifications while maintaining the gist of the invention are naturally included in the scope of the present disclosure. In addition, in order to make the explanation clearer, the drawings may be schematic in terms of the width, thickness, shape, etc. of each part compared to the actual embodiment, but they are merely examples and do not limit the interpretation of the present disclosure. In addition, in this specification and each figure, elements similar to those described above with respect to the previously mentioned figures may be given the same reference numerals, and detailed explanations may be omitted as appropriate.

[0009] (Embodiment 1) 1 is a plan view showing a schematic configuration of a detection device including an ultrasonic element according to Embodiment 1. As shown in FIG.

[0010] The ultrasonic conversion array 10 has a flexible substrate 51 and a plurality of ultrasonic conversion elements SE provided in a detection area AA of the flexible substrate 51. In the first embodiment, one first electrode 12 is arranged for one ultrasonic conversion element SE. The flexible substrate 51 has a frame area GA outside the detection area AA. A signal line selection circuit 16 and a scanning circuit 17 are arranged in the frame area GA. The control unit 20 has a control substrate 43, and an ultrasonic processing circuit 40, a power supply circuit 41, and an interface circuit 42 mounted on the control substrate 43.

[0011] The control board 43 is electrically connected to the flexible board 51 via the wiring board 31. The wiring board 31 is, for example, a flexible printed board. The control board 43 is, for example, a rigid board.

[0012] The power supply circuit 41 supplies power to the interface circuit 42 and the ultrasonic processing circuit 40 based on power supplied from the outside. The power supply circuit 41 supplies the necessary power to the signal line selection circuit 16, the scanning circuit 17, the ultrasonic processing circuit 40, and the ultrasonic conversion element SE via the wiring board 31 based on the power supplied from the outside. The power supply circuit 41 is a circuit that performs power management of the power necessary for the signal line selection circuit 16, the scanning circuit 17, the ultrasonic conversion element SE, the interface circuit 42, and the ultrasonic processing circuit 40.

[0013] The interface circuit 42 is, for example, a USB controller IC, and controls communication between the A / D conversion circuit 23 and a host controller (not shown) of a host device in which the detection system is mounted. Power supplied from an external source is supplied to the power supply circuit 41 via the interface circuit 42.

[0014] The detection area AA of the flexible substrate 51 is an area in which a plurality of ultrasonic conversion elements SE arranged in a matrix in the Dx direction (first direction) and the Dy direction (second direction) are provided. The flexible substrate 51 is, for example, a flexible printed circuit board (FPC Flexible Printed Circuits).

[0015] In the present disclosure, the Dx direction (first direction) and the Dy direction (second direction) intersect and are perpendicular to each other. In the present disclosure, the direction perpendicular to the Dx direction (first direction) and the Dy direction (second direction) is defined as the Dz direction (third direction).

[0016] As shown in Fig. 1, five ultrasonic conversion elements SE are arranged in the Dx direction and four ultrasonic conversion elements SE are arranged in the Dy direction, that is, 5 x 4 (= 20) ultrasonic conversion elements SE are provided in the detection area AA of the flexible substrate 51. The multiple ultrasonic conversion elements SE are an ultrasonic conversion array. The multiple ultrasonic conversion elements SE may be arranged in a staggered arrangement. The number of ultrasonic conversion elements SE provided in the detection area AA of the flexible substrate 51 is not limited to the embodiment.

[0017] Fig. 2 is a block diagram showing an example of the configuration of the detection device of embodiment 1. As shown in Fig. 2, the ultrasonic processing circuit 40 includes a signal transmission circuit 21, a signal detection circuit 22, an A / D conversion circuit 23, a signal processing circuit 24, a coordinate extraction circuit 25, and a memory circuit 26. The ultrasonic processing circuit 40 is, for example, a PLD (Programmable Logic Device) such as an FPGA (Field Programmable Gate Array).

[0018] Based on a signal from the signal processing circuit 24, the signal sending circuit 21 sends an oscillation pulse Set(n) (n is a natural number from 1 to N, and N is the number of electrodes in the detection area AA) to the first electrode 12 (see Figure 1) of the ultrasonic conversion element SE.

[0019] The signal detection circuit 22 is, for example, an analog front end (AFE) IC. The signal detection circuit 22 generates a detection value S(n) of each first electrode 12 based on a detection signal Det(n) (n is a natural number from 1 to N, N is a number assigned to electrodes in the detection area AA, and the maximum value is the number of electrodes) output from the ultrasonic conversion array 10. The A / D conversion circuit 23 samples the detection value S(n) of each first electrode 12 and converts it into a digital signal.

[0020] The signal processing circuit 24 performs predetermined signal processing on the detection value S(n) from the A / D conversion circuit 23. Specifically, the signal processing circuit 24 performs a comparison operation process on the detection value S(n).

[0021] The coordinate extraction circuit 25 extracts spatial coordinates of the position where the object to be detected exists based on the comparison and calculation processing result of the signal processing circuit 24. The coordinate extraction circuit 25 extracts spatial coordinates R (Rx, Ry, Rz) indicating the position of the object to be detected F in the space above the detection area AA shown in Fig. 4, using the detection value S(n) of each first electrode 12 processed by the signal processing circuit 24. Information on the spatial coordinates R (Rx, Ry, Rz) is output to an external device via the interface circuit 42 (see Fig. 1).

[0022] The memory circuit 26 has a function of storing information on the spatial coordinates R (Rx, Ry, Rz) extracted by the coordinate extraction circuit 25.

[0023] 3 is a schematic diagram showing a schematic cross-sectional configuration of the detection device of embodiment 1. The detection device 1 of embodiment 1 is disposed opposite the display panel 200. In a plan view, the detection area AA (see FIG. 1) of the ultrasonic conversion array 10 and the display area DA of the display panel 200 are disposed so as to overlap in the Dz direction (third direction). Note that in the illustrated example, the detection area AA of the ultrasonic conversion array 10 and the display area DA of the display panel 200 are disposed so as to entirely overlap, but the ultrasonic conversion array 10 may be disposed so as to overlap only a portion of the display panel 200.

[0024] The display panel 200 is, for example, a liquid crystal display (LCD). The display panel 200 may be, for example, an organic light emitting diode (OLED) display or an inorganic light emitting diode (micro LED, mini LED).

[0025] In the first embodiment, the ultrasonic transducer array 10 includes a flexible substrate 51, a frame layer 52, a circuit layer 53, a piezoelectric layer 54, and a protective layer 55. The ultrasonic transducer array 10 is stacked in the order of the frame layer 52, the flexible substrate 51, the circuit layer 53, the piezoelectric layer 54, and the protective layer 55 from the side opposite the display panel 200.

[0026] FIG. 4 is a schematic diagram showing the relationship between the object to be detected and the detection device in the space above the detection area. The ultrasonic conversion element SE converts the oscillation pulse Set(n) to generate an ultrasonic wave Tu, and the ultrasonic wave Tu is transmitted. The ultrasonic conversion element SE receives the ultrasonic wave Ru reflected by the object to be detected F (e.g., the operator's finger, etc.) and converts it into a detection signal Det(n). The coordinate extraction circuit 25 (see FIG. 2) generates a spatial coordinate indicating the position of the object to be detected F (e.g., the operator's finger, etc.) on the detection area AA based on the detection value S(n) generated from the detection signal Det(n). The ultrasonic conversion element SE can also measure the distance to the object to be detected F (e.g., the operator's finger, etc.) based on the time it takes to receive the ultrasonic wave Ru reflected by the object to be detected F (e.g., the operator's finger, etc.).

[0027] Fig. 5 is a circuit diagram showing one of the detection regions of the embodiment 1. Fig. 6 is a plan view showing the detection regions of the embodiment 1.

[0028] The scanning circuit 17 shown in FIG. 1 is a circuit that drives the multiple scanning lines 61Tx and 61Rx shown in FIG. 5 and FIG. 6 based on various control signals. The scanning circuit 17 serves as a driving circuit that scans the scanning lines 61Tx of the multiple ultrasonic conversion elements SE and a driving circuit that scans the scanning lines 61Rx of the multiple ultrasonic conversion elements SE. The scanning circuit 17 sequentially selects the multiple scanning lines 61Tx and 61Rx, and supplies gate driving signals to the selected scanning lines 61Tx and 61Rx. In this way, the scanning circuit 17 selects the multiple ultrasonic conversion elements SE connected to the scanning lines 61Tx and 61Rx. The scanning lines 61Tx and 61Rx are made of metal materials such as aluminum (Al), gold, molybdenum, and titanium.

[0029] The signal line selection circuit 16 is a switch circuit that sequentially or simultaneously selects the multiple transmission signal lines 62Tx and the multiple reception signal lines 62Rx. The signal line selection circuit 16 is, for example, a multiplexer. The signal line selection circuit 16 connects the selected transmission signal line 62Tx to the signal sending circuit 21 based on a selection signal supplied from the ultrasonic processing circuit 40. The signal line selection circuit 16 connects the selected reception signal line 62Rx to the signal detection circuit 22 based on a selection signal supplied from the ultrasonic processing circuit 40. As a result, the signal line selection circuit 16 outputs the detection signal Det(n) of the ultrasonic conversion element SE to the signal detection circuit 22. The transmission signal lines 62Tx and reception signal lines 62Rx are made of metal materials such as aluminum (Al), gold, molybdenum, and titanium.

[0030] Each ultrasonic transducer SE includes a first switching element Tr1, a second switching element Tr2, and a membrane transducer UE. The first switching element Tr1 controls the switching of the connection between the transmission signal line 62Tx and the membrane transducer UE. The second switching element Tr2 controls the switching of the connection between the reception signal line 62Rx and the membrane transducer UE.

[0031] The first electrode 12 at one end of the membrane vibrator UE is connected to the drain of the first switching element Tr1 and the drain of the second switching element Tr2, and the second electrode 14 at the other end of the membrane vibrator UE is connected to a reference potential wiring 63 to which a reference potential GND is supplied. As shown in FIG. 6, the first electrode 12 is connected to the drain of the first switching element Tr1 and the drain of the second switching element Tr2 via a connection wiring 12W. The transmission signal line 62Tx is connected to the source of the first switching element Tr1. The reception signal line 62Rx is connected to the source of the second switching element Tr2. The scanning line 61Tx is connected to the gate of the first switching element Tr1. The scanning line 61Rx is connected to the gate of the second switching element Tr2. Note that the connections to the drains of the first switching element Tr1 and the second switching element Tr2 and the connections to the sources of the first switching element Tr1 and the second switching element Tr2 may be interchanged. The reference potential wiring 63 is made of a metal material such as aluminum (Al), gold, molybdenum, or titanium.

[0032] The circuits shown in FIGS. 5 and 6 may further include other transistors, signal amplifier circuits, bandpass filters, capacitors, and the like.

[0033] FIG. 7 is a timing chart showing the operation of one ultrasonic conversion element in the first embodiment. As shown in FIG. 7, ultrasonic transmission and ultrasonic reception are processed in a time-division manner. In ultrasonic transmission, a gate drive signal is transmitted to the scanning line 61Tx selected by the scanning circuit 17, and the signal line selection circuit 16 transmits an oscillation pulse Set(n) from the signal transmission circuit 21 to the selected transmission signal line 62Tx. The membrane oscillator UE vibrates based on the oscillation pulse Set(n) to generate ultrasonic waves Tu. The frequency of the ultrasonic waves Tu is, for example, 1 kHz or more and 1 MHz or less.

[0034] Next, the gate drive signal is transmitted to the scanning line 61Rx selected by the scanning circuit 17, and the signal line selection circuit 16 connects the selected reception signal line 62Rx to the signal detection circuit 22. Receiving the ultrasonic wave Ru, the membrane vibrator UE converts the ultrasonic wave Ru into an electric detection signal Det(n), and the detection signal Det(n) is transmitted to the signal detection circuit 22. In the illustrated example, the timing at which the gate drive signal is transmitted to the scanning line 61Tx is different from the timing at which the gate drive signal is transmitted to the scanning line 61Rx, but the timing at which the gate drive signal is transmitted to the scanning line 61Tx and the scanning line 61Rx may be simultaneous. By transmitting them simultaneously, there is a risk that the oscillation pulse Set(n) and the detection signal Det(n) will be mixed up, but it is possible to detect a closer object.

[0035] Fig. 8 is a cross-sectional view showing the detection area and frame area of ​​the first embodiment. In Fig. 8, a cross-section of one ultrasonic conversion element SE in the detection area AA is shown together with a cross-section of the frame area GA. The flexible substrate 51 is a flexible resin substrate, for example, polyimide resin is used. The thickness of the flexible substrate 51 is 1 μm or more and 100 μm or less.

[0036] A cavity FH is formed for each ultrasonic transducer SE in the frame layer 52. The region overlapping with the cavity FH in plan view becomes the membrane transducer UE. As shown in FIG. 6, the cavity FH surrounds the first electrode 12 in plan view.

[0037] The frame layer 52 is, for example, a polyimide resin or a metal foil. The thickness of the frame layer 52 is 1 μm or more and 100 μm or less. The frame layer 52 is harder to bend than the flexible substrate 51. For example, when the frame layer 52 is made of the same material as the flexible substrate 51, the frame layer 52 is thicker than the flexible substrate 51, so that the first electrode 12 and the flexible substrate 51 overlapping the cavity FH in a planar view vibrate together and function as a membrane vibrator UE. When the frame layer 52 is made of a material different from that of the flexible substrate 51, the Young's modulus and thickness of the frame layer 52 are set to be harder to bend than the flexible substrate 51.

[0038] The cavity FH is circular and has a diameter φD. This causes the membrane vibrator UE to also be circular. The diameter φD is smaller than the area surrounded by the scanning line 61Tx, the scanning line 61Rx, the transmission signal line 62Tx, and the reception signal line 62Rx shown in FIG. 6. The diameter φD is, for example, 0.1 mm or more and 5 mm or less.

[0039] The piezoelectric layer 54 is formed of an inorganic material such as PZT (lead zirconate titanate) or AlN (aluminum nitride) or an organic material such as polyvinylidene fluoride resin (polyvinylidene difluoride resin). The thickness of the piezoelectric layer 54 is, for example, 10 nm or more and 10,000 nm or less. The piezoelectric layer 54 may include a buffer layer, a crystal adjustment layer, a protective layer, a matching layer, a backing layer, etc., as necessary. The piezoelectric layer 54 is formed over the entire detection area AA.

[0040] The region where the piezoelectric layer 54 is formed may be the same size as the region of the cavity FH in a planar view and may be provided so as to overlap the region of the cavity FH in a planar view. The piezoelectric layer 54 may be similar in shape to the region of the cavity FH in a planar view and larger than the boundary of the region of the cavity FH. Alternatively, the piezoelectric layer 54 may be similar in shape to the region of the cavity FH in a planar view, smaller than the region of the cavity FH, and larger than the first electrode 12.

[0041] The circuit layer 53 and the piezoelectric layer 54 are formed on a glass substrate, and the circuit layer 53 and the piezoelectric layer 54 are transferred from the glass substrate to the flexible substrate 51. The piezoelectric layer 54 is formed on the glass substrate. The first electrode 12 is formed on the piezoelectric layer 54. The first resin layer 71 is formed on the first electrode 12. The first electrode 12 is made of a metal material such as aluminum (Al), gold, molybdenum, titanium, or the like. Alternatively, the first electrode 12 may be an alloy material containing at least one of these metal materials or a laminate of at least two of these metal materials.

[0042] As viewed from the glass substrate, a gate electrode 82 is formed on the first resin layer 71. A second resin layer 72 is laminated on the gate electrode 82. A source electrode 83 and a drain electrode 84 are formed on the second resin layer 72. The drain electrode 84 and the first electrode 12 are electrically connected via a through hole 85. The second resin layer 72 around the source electrode 83 and the drain electrode 84 is covered with a third resin layer 73. A semiconductor layer 81 is formed on the source electrode 83 and the drain electrode 84, and the semiconductor layer 81 is bonded to each of the source electrode 83 and the drain electrode 84. The semiconductor layer 81, the gate electrode 82, the source electrode 83, and the drain electrode 84 function as a first switching element Tr1. The gate electrode 82, the source electrode 83, the drain electrode 84, and the through hole 8 are made of a metal material such as aluminum (Al), gold, molybdenum, or titanium. Alternatively, the gate electrode 82, the source electrode 83, the drain electrode 84 and the through hole 85 may be an alloy material containing at least one of these metal materials or a laminate of at least two of these metal materials. The second switching element Tr2 has the same configuration as the first switching element Tr1, and therefore a detailed description thereof will be omitted.

[0043] The semiconductor layer 81 is an oxide semiconductor. More preferably, the semiconductor layer 81 is a transparent amorphous oxide semiconductor (TAOS) among oxide semiconductors. By using an oxide semiconductor for the semiconductor layer 81, leakage current is suppressed. That is, leakage current from a non-selected transistor of the first switching element Tr1 or the second switching element Tr2 can be reduced. Therefore, the detection device 1 can improve the S / N ratio. However, the semiconductor layer 81 is not limited thereto, and may be a microcrystalline oxide semiconductor, an amorphous oxide semiconductor, polysilicon, low temperature polycrystalline silicon (LTPS), or the like.

[0044] A fourth resin layer 74 is formed on the semiconductor layer 81 and the third resin layer 73. Since the circuit layer 53 is transferred from the glass substrate to the flexible substrate 51, the lamination order is reversed when viewed from the flexible substrate 51.

[0045] The second resin layer 72 is an inorganic insulating film such as silicon nitride. The first resin layer 71, the third resin layer 73, and the fourth resin layer 74 may be inorganic insulating films or organic insulating films, and are, for example, organic insulating films such as acrylic resin. If the first resin layer 71, the third resin layer 73, and the fourth resin layer 74 are organic insulating films, cracks are less likely to occur in the circuit layer 53. The thickness of the circuit layer 53 may be partially changed, and for example, the thickness of at least one of the first resin layer 71, the third resin layer 73, and the fourth resin layer 74 in the region of the cavity FH that overlaps in a plan view may be reduced or removed.

[0046] A second electrode 14 is formed on a second surface of the piezoelectric layer 54 opposite to the first surface on which the first electrode 12 is formed. The second electrode 14 is also called a counter electrode, and is connected to a reference potential wiring 63 in the frame area GA via a through hole 87. The second electrode 14 is made of a metal material such as aluminum (Al), gold, molybdenum, or titanium. Alternatively, the second electrode 14 may be an alloy material containing at least one of these metal materials or a laminate of at least two of these metal materials.

[0047] The second electrode 14 is covered with a protective layer 55 of an organic insulating film such as acrylic resin. The second electrode 14 contacts the surface of the piezoelectric layer 54 opposite to the surface in contact with the first electrode 12, and the piezoelectric layer 54 is sandwiched between the first electrode 12 and the second electrode 14. The second electrode 14 is provided across the multiple ultrasonic conversion elements SE, and serves as the second electrode 14 common to the multiple ultrasonic conversion elements SE. This reduces the electrical resistance of the second electrode 14.

[0048] The flexible substrate 51 and the frame layer 52 are bonded via an adhesive layer 56. The adhesive layer 56 has adhesive properties on both sides, and in a state where it is bonded to the frame layer 52, a cavity FH is opened by pressing or the like.

[0049] 8, the ultrasonic transducer SE is formed by transfer, but may be formed by other methods. For example, a flexible substrate 51 is formed on a glass substrate, and a circuit layer 53, a piezoelectric layer 54, a second electrode 14, and a protective layer 55 are formed thereon. Thereafter, the flexible substrate 51 may be peeled off from the glass substrate, and the flexible substrate 51 and the frame layer 52 may be bonded. In this case, since the circuit layer 53, the piezoelectric layer 54, the second electrode 14, and the protective layer 55 are formed by laminating them in order, the lamination order is not reversed when viewed from the flexible substrate 51.

[0050] The first switching element Tr1 is provided at a position that does not overlap the cavity FH in a plan view, and the first switching element Tr1 and the first electrode 12 are electrically connected at a position that does not overlap the cavity FH in a plan view. This makes it possible to suppress the deterioration of the first switching element Tr1 and the possibility of disconnection of the connection between the first switching element Tr1 and the first electrode 12 due to vibration of the membrane oscillator UE.

[0051] The frame layer 52 may be formed by covering the region of the cavity FH with photoresist, coating or forming a film around the photoresist, and then removing the photoresist. Alternatively, the frame layer 52 may be formed directly on the surface of the flexible substrate 51 by 3D printing.

[0052] As described above, the detection device 1 of the first embodiment includes a plurality of ultrasonic conversion elements SE that transmit and receive ultrasonic waves. The detection device 1 includes a laminate and a frame layer 52 laminated on the first surface of the laminate and the second surface opposite to the first surface. The laminate includes a flexible substrate 51, a circuit layer 53 laminated on the flexible substrate 51, and a piezoelectric layer 54 laminated on the circuit layer 53. Specifically, the frame layer 52 is bonded to the flexible substrate 51. The ultrasonic conversion element SE includes a first electrode 12 in contact with the piezoelectric layer 54 and a second electrode 14 in contact with the piezoelectric layer 54. The frame layer 52 has a cavity FH at a position overlapping with the first electrode 12 in a plan view.

[0053] With this configuration, the flexible substrate 51 is more likely to bend in response to vibration than substrates such as glass or silicon, and therefore damage is less likely to occur at the bonding surfaces of the flexible substrate 51, the circuit layer 53, and the piezoelectric layer 54. Also, the membrane vibrator UE can be manufactured inexpensively by simply bonding the flexible substrate 51 to the frame layer 52 having the cavity FH.

[0054] (Embodiment 2) Fig. 9 is a cross-sectional view showing a detection area of ​​embodiment 2. In embodiment 2, the same components as those in embodiment 1 are given the same reference numerals and may not be described. Fig. 9 shows a cross section of one ultrasonic conversion element SE of the detection area AA.

[0055] In the first embodiment, the frame layer 52 is bonded to one surface of the flexible substrate 51, but in the second embodiment, the frame layer 52 is on the opposite side to the first embodiment with respect to the circuit layer 53 and the piezoelectric layer .

[0056] A frame layer 52 is bonded to one surface of the protective layer 55 via an adhesive layer 56. A cavity FH is formed in the frame layer 52 for each ultrasonic conversion element SE.

[0057] As described above, the detection device 1 of the second embodiment includes a plurality of ultrasonic conversion elements SE that transmit and receive ultrasonic waves. The detection device 1 includes a laminate and a frame layer 52 laminated on the second surface of the first surface and the second surface opposite to the first surface of the laminate. The laminate includes a flexible substrate 51, a circuit layer 53 laminated on the flexible substrate 51, and a piezoelectric layer 54 laminated on the circuit layer 53. Specifically, the frame layer 52 is bonded to a protective layer 55 on the side opposite to the side on which the flexible substrate 51 of the laminate is located. The ultrasonic conversion element SE includes a first electrode 12 in contact with the piezoelectric layer 54 and a second electrode 14 in contact with the piezoelectric layer 54. The frame layer 52 has a cavity FH at a position overlapping with the first electrode 12 in a plan view.

[0058] With this configuration, the flexible substrate 51 is more likely to bend in response to vibration than substrates such as glass or silicon, and therefore damage is less likely to occur at the bonding surfaces of the flexible substrate 51, the circuit layer 53, and the piezoelectric layer 54. Also, the membrane vibrator UE can be manufactured inexpensively by simply bonding the flexible substrate 51 to the frame layer 52 having the cavity FH.

[0059] Furthermore, since the frame layer 52 is closer to the circuit layer 53 and the piezoelectric layer 54 than in the first embodiment, crosstalk, in which vibration of the piezoelectric layer 54 of one ultrasonic conversion element SE propagates to an adjacent ultrasonic conversion element SE, is suppressed.

[0060] (Embodiment 3) Fig. 10 is a cross-sectional view showing a detection area of ​​embodiment 3. In embodiment 3, the same components as those in embodiments 1 and 2 are denoted by the same reference numerals, and the description thereof may be omitted. Fig. 10 shows a cross section of one ultrasonic conversion element SE of the detection area AA.

[0061] A frame layer 52A is bonded via an adhesive layer 56A to one surface of the flexible substrate 51. A cavity FHA is formed in the frame layer 52A for each ultrasonic conversion element SE.

[0062] A frame layer 52B is bonded via an adhesive layer 56B to one surface of the protective layer 55. A cavity FHB is formed in the frame layer 52B for each ultrasonic conversion element SE.

[0063] As described above, the detection device 1 of the third embodiment includes a plurality of ultrasonic conversion elements SE that transmit and receive ultrasonic waves. The detection device 1 includes a laminate, a frame layer 52A laminated on a first surface of the laminate, and a frame layer 52B laminated on a second surface opposite to the first surface. The laminate includes a flexible substrate 51, a circuit layer 53 laminated on the flexible substrate 51, and a piezoelectric layer 54 laminated on the circuit layer 53. Specifically, the circuit layer 53 and the piezoelectric layer 54 are sandwiched between the frame layer 52A and the frame layer 52B. The ultrasonic conversion element SE includes a first electrode 12 in contact with the piezoelectric layer 54 and a second electrode 14 in contact with the piezoelectric layer 54. The frame layer 52 has a cavity FHA and a cavity FHB at a position overlapping with the first electrode 12 in a plan view. The cavity FHA of one frame layer 52A and the cavity FHB of the other frame layer 52B are located at positions overlapping each other in a plan view.

[0064] With this configuration, the flexible substrate 51 is more likely to bend in response to vibration than substrates such as glass or silicon, and therefore damage is less likely to occur at the bonding surfaces of the flexible substrate 51, the circuit layer 53, and the piezoelectric layer 54. Also, the membrane vibrator UE can be manufactured inexpensively by simply bonding the flexible substrate 51 to the frame layer 52 having the cavity FH.

[0065] Since the circuit layer 53 and the piezoelectric layer 54 are sandwiched between the frame layers 52A and 52B, crosstalk, in which vibration of the piezoelectric layer 54 of one ultrasonic conversion element SE propagates to an adjacent ultrasonic conversion element SE, is suppressed.

[0066] (Embodiment 4) Fig. 11 is a cross-sectional view showing a detection area of ​​embodiment 4. In embodiment 4, the same components as those in embodiments 1 to 3 are given the same reference numerals and may not be described. Fig. 11 shows a cross section of one ultrasonic conversion element SE of the detection area AA.

[0067] 11, the reference potential wiring 63 is routed to each ultrasonic transducer SE. The reference potential wiring 63 is formed in a layer different from the source electrode 83 and the drain electrode 84, and is formed in the same layer as the semiconductor layer 81, for example.

[0068] The relay wiring 88, which is in the same layer as the first electrode 12, is connected to the reference potential wiring 63 via a through hole 87A. The second electrode 14 and the relay wiring 88 are connected to each other via a through hole 89. This makes it possible to narrow the frame area GA.

[0069] The second electrodes 14 of the ultrasonic transducers SE are provided in areas that overlap with the cavities FH in a plan view. Since the adjacent second electrodes 14 are separated from each other, crosstalk of ultrasonic waves Ru detected by the adjacent ultrasonic transducers SE is reduced.

[0070] Since the second electrode 14 and the reference potential wiring 63 are electrically connected at a position that does not overlap the cavity FH in a plan view, the possibility of the reference potential wiring 63 being disconnected is reduced.

[0071] (Embodiment 5) Fig. 12 is a cross-sectional view showing a detection area of ​​embodiment 5. Fig. 13 is a circuit diagram showing one of the detection areas of embodiment 5. In embodiment 4, the same components as those in embodiments 1 to 4 are given the same reference numerals, and the description may be omitted. Fig. 12 shows a cross section of one ultrasonic conversion element SE of detection area AA.

[0072] 12, the second electrode 14 is electrically connected to the third switching element Tr3. The third switching element Tr3 has the same configuration as the first switching element Tr1, so a detailed description thereof will be omitted. The drain electrode 84 of the third switching element Tr3 and the second electrode 14 are electrically connected via a through hole 85, a relay wiring 88, and a through hole 89.

[0073] Each ultrasonic conversion element SE includes a first switching element Tr1, a second switching element Tr2, a third switching element Tr3, a fourth switching element Tr4, and a membrane oscillator UE. The first switching element Tr1 controls the switching of the connection between the transmission signal line 62Tx and the membrane oscillator UE. The second switching element Tr2 controls the switching of the connection between the reception signal line 62Rx and the membrane oscillator UE. The third switching element Tr3 controls the switching of the connection between the transmission signal line 62Txx and the membrane oscillator UE. The second switching element Tr2 controls the switching of the connection between the reference potential wiring 63 and the membrane oscillator UE.

[0074] The second electrode 14 is connected to the drain of the third switching element Tr3. The transmission signal line 62Txx is connected to the source of the third switching element Tr3. A signal having a phase opposite to that of the oscillation pulse Set(n) of the transmission signal line 62Txx (first transmission signal line) is transmitted to the transmission signal line 62Txx (second transmission signal line). In addition, the second electrode 14 is connected to the drain of the fourth switching element Tr4. The reference potential wiring 63 is connected to the source of the fourth switching element Tr4.

[0075] During ultrasonic transmission, the first switching element Tr1 and the third switching element Tr3 are simultaneously turned on, and the second switching element Tr2 and the fourth switching element Tr4 are simultaneously turned off. The transmission signal line 62Tx transmits an oscillation pulse Set(n) signal to the first electrode 12 via the first switching element Tr1, and the transmission signal line 62Txx transmits a signal of the opposite phase to the oscillation pulse Set(n) to the second electrode 14 via the third switching element Tr3. As a result, the amplitude of the signal applied to the piezoelectric layer 54 is doubled compared to the first embodiment, and the output of the ultrasonic wave is improved.

[0076] During ultrasonic reception, the first switching element Tr1 and the third switching element Tr3 are simultaneously turned off, and the second switching element Tr2 and the fourth switching element Tr4 are simultaneously turned on. The reception signal line 62Rx and the first electrode 12 are connected via the second switching element Tr2, and the reference potential wiring 63 and the second electrode 14 are connected via the third switching element Tr3. As a result, the detection signal Det(n) of the ultrasonic conversion element SE is output to the signal detection circuit 22.

[0077] The second electrodes 14 of the ultrasonic transducers SE are provided in areas that overlap with the cavities FH in a plan view. Adjacent second electrodes 14 are separated from each other. In the ultrasonic transducers SE that are not selected by the scanning circuit 17, the second electrodes 14 are at the reference potential GND, and noise from the ultrasonic transducers SE that are not selected by the scanning circuit 17 is suppressed.

[0078] In the ultrasonic conversion element SE selected by the scanning circuit 17, the amplitude of the membrane vibration body UE increases because a reverse signal of the oscillation pulse Set(n) is transmitted to the second electrode 14. In the ultrasonic conversion element SE not selected by the scanning circuit 17, the second electrode 14 becomes the reference potential GND, and the influence of the vibration of the other ultrasonic conversion elements SE can be suppressed.

[0079] (Embodiment 6) Fig. 14 is a cross-sectional view showing a detection area of ​​the sixth embodiment. Fig. 15 is a plan view showing a first electrode and a second electrode of the sixth embodiment. Fig. 14 is a cross-sectional view taken along line XIV-XIV of Fig. 15. In the sixth embodiment, the same components as those in the first to fifth embodiments are given the same reference numerals, and the description thereof may be omitted. Fig. 14 shows a cross section of one ultrasonic conversion element SE of the detection area AA.

[0080] 14, the reference potential wiring 63 is routed to each ultrasonic transducer SE. The reference potential wiring 63 is formed in a layer different from the source electrode 83 and the drain electrode 84, and is formed in the same layer as the semiconductor layer 81, for example.

[0081] The second electrode 14, which is in the same layer as the first electrode 12, is connected to the reference potential wiring 63 via a through hole 87B. As shown in Fig. 15, the second electrode 14 is in contact with the same surface of the piezoelectric layer 54 as the surface to which the first electrode 12 is in contact. The second electrode 14 is located inside the first electrode 12. This allows the frame area GA to be narrowed.

[0082] The second electrodes 14 of the ultrasonic transducers SE are provided in areas that overlap with the cavities FH in a plan view. Since the adjacent second electrodes 14 are separated from each other, crosstalk of ultrasonic waves Ru detected by the adjacent ultrasonic transducers SE is reduced.

[0083] The region where the second electrode 14 is formed is similar in shape to the region of the cavity FH in a plan view, but is smaller than the region of the cavity FH. The region where the first electrode 12 is formed overlaps the boundary of the region of the cavity FH in a plan view, and the first electrode 12 is annular.

[0084] Fig. 16 is a plan view showing a first electrode and a second electrode according to Modification 1 of Embodiment 6. As shown in Fig. 16, in Modification 1, the second electrode 14 is rectangular, and the outer diameter of the first electrode 12 is rectangular and annular. The first electrode 12 and the second electrode 14 are in the same layer as in Embodiment 6.

[0085] Fig. 17 is a plan view showing a first electrode and a second electrode according to Modification 2 of the sixth embodiment. As shown in Fig. 17, in Modification 2, the region where the second electrode 14 is formed is similar in shape to the region of the cavity FH in a plan view, but is smaller than the region of the cavity FH. The region where the first electrode 12 is formed overlaps the boundary of the region of the cavity FH in a plan view, and the first electrode 12 is annular. The first electrode 12 and the second electrode 14 are in the same layer as in the sixth embodiment.

[0086] The through hole 87B is disposed at a position outside the first electrode 12, and the through hole 87B and the second electrode 14 are connected by a wire. As a result, the reference potential wiring 63 does not overlap with the region that overlaps with the region of the cavity FH in a plan view, so that the reference potential wiring 63 is less susceptible to the effects of vibration of the membrane vibrating body UE, and the reliability of the detection device 1 is improved.

[0087] Fig. 18 is a plan view showing a first electrode and a second electrode according to Modification 3 of Embodiment 6. As shown in Fig. 18, in Modification 3, the first electrode 12 and the second electrode 14 are rectangular and adjacent to each other. The first electrode 12 and the second electrode 14 are in the same layer as in Embodiment 6.

[0088] The through hole 87B is disposed at a position outside the region overlapping with the region of the cavity FH in a plan view, and the through hole 87B and the second electrode 14 are connected by a wire. As a result, the reference potential wiring 63 does not overlap with the region overlapping with the region of the cavity FH in a plan view, so that the reference potential wiring 63 is less susceptible to the effects of vibration of the membrane vibrating body UE, and the reliability of the detection device 1 is improved.

[0089] Fig. 19 is a plan view showing a first electrode and a second electrode according to Modification 4 of Embodiment 6. As shown in Fig. 19, in Modification 4, the first electrode 12 and the second electrode 14 are comb-tooth electrodes that interdigitate with each other. Note that the first electrode 12 and the second electrode 14 are in the same layer as in Embodiment 6.

[0090] The through hole 87B is disposed at a position outside the region overlapping with the region of the cavity FH in a plan view, and the through hole 87B and the second electrode 14 are connected by a wire. As a result, the reference potential wiring 63 does not overlap with the region overlapping with the region of the cavity FH in a plan view, so that the reference potential wiring 63 is less susceptible to the effects of vibration of the membrane vibrating body UE, and the reliability of the detection device 1 is improved.

[0091] (Embodiment 7) Fig. 20 is a plan view showing the detection area of ​​the seventh embodiment. Fig. 21 is a cross-sectional view showing the detection area of ​​the seventh embodiment. Fig. 20 is a cross-section taken along line XX-XX' of Fig. 21. In the seventh embodiment, the same components as those in the first to sixth embodiments are given the same reference numerals, and the description thereof may be omitted. Fig. 20 shows a cross section of one ultrasonic conversion element SE of the detection area AA.

[0092] In the seventh embodiment, a first electrode 12Tx and a first electrode 12Rx are arranged for one ultrasonic conversion element SE. The first electrode 12Tx is an ultrasonic transmission electrode that generates an ultrasonic wave Tu, and the first electrode 12Rx is an ultrasonic reception electrode that receives an ultrasonic wave Ru.

[0093] Each ultrasonic conversion element SE includes a first switching element Tr1, a second switching element Tr2, a membrane oscillator UETx, and a membrane oscillator UERx. The first switching element Tr1 and the first electrode 12Tx are electrically connected via a through hole 85Tx. The first switching element Tr1 controls the switching of the connection between the transmission signal line 62Tx and the membrane oscillator UETx. The second switching element Tr2 and the first electrode 12Rx are electrically connected via a through hole 85Rx. The second switching element Tr2 controls the switching of the connection between the reception signal line 62Rx and the membrane oscillator UERx.

[0094] In the frame layer 52, a first cavity FHTx and a second cavity FHRx are opened for each ultrasonic conversion element SE. In the frame layer 52, the first cavity FHTx is located at a position overlapping with one of the first electrodes 12Tx in a plan view, and the second cavity FHRx is located at a position overlapping with the other of the first electrodes 12Rx. The region overlapping with the first cavity FHTx in a plan view becomes the membrane oscillator UETx. The region overlapping with the second cavity FHRx in a plan view becomes the membrane oscillator UERx.

[0095] The transmission of ultrasonic waves and the reception of ultrasonic waves are processed in a time-division manner. In the seventh embodiment, the membrane oscillator UETx and the membrane oscillator UERx are operated separately, so even if the switching time from the transmission of ultrasonic waves to the reception of ultrasonic waves is shortened, the influence of the membrane oscillator UETx on the membrane oscillator UERx is small. As a result, the detection cycle of the detection device 1 is shortened, and the detection accuracy is improved.

[0096] Note that the first electrodes 12Tx may be arranged on the ultrasonic conversion elements SE in the first row, and the first electrodes 12Rx may be arranged on the ultrasonic conversion elements SE in the second row.

[0097] Although the preferred embodiment of the present disclosure has been described above, the present disclosure is not limited to such an embodiment. The contents disclosed in the embodiment are merely examples, and various modifications are possible within the scope of the present disclosure. For example, the embodiment is described as an ultrasonic transducer for both transmission and reception, but it can also be applied to an ultrasonic transducer for transmission only or reception only. Appropriate modifications made within the scope of the present disclosure naturally fall within the technical scope of the present disclosure. [Explanation of symbols]

[0098] 1. Detection device 10 Ultrasonic transducer array 12, 12Rx, 12Tx 1st electrode 12W connection wiring 14 2nd electrode 16 Signal line selection circuit 17 Scanning circuit 20 Control section 21 Signal transmission circuit 22 Signal detection circuit 51 Flexible substrate 52, 52A, 52B Frame Layers 53 circuit layer 54 Piezoelectric layer 55 Protective layer 56, 56A, 56B adhesive layer 61Rx, 61Tx scan lines 62Rx Receive signal line 62Tx, 62Txx Transmission signal line 63 Reference potential wiring 200 Display Panel AA detection area F Object to be detected FH, FHA, FHB Cavity FHTx 1st Cavity FHRx 2nd Cavity GA Frame area UE, UERx, UETx Membrane Vibrator

Claims

1. A detection device including a plurality of ultrasonic transducer elements for transmitting and receiving ultrasonic waves, A flexible substrate; a circuit layer including a plurality of first electrodes and at least one second electrode and laminated to the flexible substrate; a piezoelectric layer laminated on the circuit layer; A laminate comprising: a frame layer laminated on at least one of a first surface of the laminate and a second surface opposite to the first surface; One of the ultrasonic transducer elements includes: At least one of the first electrodes in contact with the piezoelectric layer; at least one second electrode in contact with the piezoelectric layer; The frame layer has a cavity at a position overlapping with the first electrode in a plan view. Detection device.

2. the second electrode is in contact with a surface of the piezoelectric layer opposite to a surface of the piezoelectric layer in contact with the first electrode, and the piezoelectric layer is sandwiched between the first electrode and the second electrode. The detection device according to claim 1 .

3. The second electrode is provided across the plurality of ultrasonic transducer elements.

3. The detection device according to claim 2.

4. The second electrodes are provided on the ultrasonic transducer elements, 3. The detection device according to claim 2.

5. The second electrodes are provided on the ultrasonic transducers, The second electrode is in contact with a surface of the piezoelectric layer on the same side as a surface of the piezoelectric layer that is in contact with the first electrode. The detection device according to claim 1 .

6. The second electrodes are provided on the ultrasonic transducers, the first electrode is annular; The second electrode is surrounded by the first electrode.

6. The detection device according to claim 5.

7. The second electrodes are provided on the ultrasonic transducers, The first electrode and the second electrode are disposed adjacent to each other.

6. The detection device according to claim 5.

8. Further comprising a reference potential wiring for supplying a potential to the second electrode; The reference potential wiring is routed to the ultrasonic transducer, the second electrode and the reference potential wiring are electrically connected at a position not overlapping with the cavity in a plan view; 5. The detection device according to claim 4.

9. The ultrasonic transducer element includes a first switching element, the first switching element and the first electrode are electrically connected at a position not overlapping with the cavity in a plan view; The detection device according to claim 1 .

10. further comprising a plurality of transmit signal lines and a plurality of receive signal lines; The ultrasonic transducer includes a first switching element and a second switching element, The detection device according to claim 1 , wherein the first electrode is connected to one of the transmission signal lines via the first switching element, and is connected to one of the reception signal lines via the second switching element.

11. The second electrodes are provided on the ultrasonic transducers, The ultrasonic transducer further includes a third switching element, the first electrode is connected to a first transmission signal line among the plurality of transmission signal lines via the first switching element; The detection device according to claim 10 , wherein the second electrode is connected, via the third switching element, to a second transmission signal line through which an oscillation pulse having a phase opposite to that of the first transmission signal line is transmitted.

12. Further comprising a reference potential wiring for supplying a potential to the second electrode; The ultrasonic transducer further includes a fourth switching element, The detection device according to claim 11 , wherein the second electrode is connected to the reference potential wiring via the fourth switching element.

13. One of the ultrasonic transducer elements includes: The piezoelectric layer includes two first electrodes in contact with the piezoelectric layer, The detection device according to claim 1 , wherein the frame layer has a first cavity at a position overlapping one of the first electrodes in a plan view, and a second cavity at a position overlapping the other of the first electrodes.

14. The first electrode is an electrode for transmitting ultrasonic waves, The other first electrode is an electrode for receiving ultrasonic waves.

14. The detection device according to claim 13.

15. the frame layer is bonded to the flexible substrate; Detector device according to any one of claims 1 to 14.

16. The frame layer is bonded to the laminate on the side opposite to the side on which the flexible substrate is located. Detector device according to any one of claims 1 to 14.

17. The two frame layers sandwich the laminate, The cavity of one of the frame layers and the cavity of the other frame layer are positioned so as to overlap each other in a plan view. Detector device according to any one of claims 1 to 14.

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