US20060043843A1 - Ultrasonic sensor - Google Patents

Ultrasonic sensor Download PDF

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Publication number
US20060043843A1
US20060043843A1 US11/208,724 US20872405A US2006043843A1 US 20060043843 A1 US20060043843 A1 US 20060043843A1 US 20872405 A US20872405 A US 20872405A US 2006043843 A1 US2006043843 A1 US 2006043843A1
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US
United States
Prior art keywords
ultrasonic sensor
receiving
conversion means
converters
transmission
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US11/208,724
Other languages
English (en)
Inventor
Makiko Sugiura
Takahiko Yoshida
Masatoshi Tokunaga
Yasutoshi Suzuki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Denso Corp
Soken Inc
Original Assignee
Denso Corp
Nippon Soken Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Denso Corp, Nippon Soken Inc filed Critical Denso Corp
Assigned to NIPPON SOKEN, INC., DENSO CORPORATION reassignment NIPPON SOKEN, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: TOKUNAGA, MASATOSHI, SUGIURA, MAKIKO, SUZUKI, YASUTOSHI, YOSHIDA, TAKAHIKO
Publication of US20060043843A1 publication Critical patent/US20060043843A1/en
Priority to US11/586,561 priority Critical patent/US7329975B2/en
Priority to US12/003,096 priority patent/US7525237B2/en
Abandoned legal-status Critical Current

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
    • G01H11/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by detecting changes in electric or magnetic properties
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/52—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S15/00
    • G01S7/521—Constructional features
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
    • B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
    • B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
    • B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
    • B06B1/0622—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements on one surface
    • B06B1/0629—Square array
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16M—FRAMES, CASINGS OR BEDS OF ENGINES, MACHINES OR APPARATUS, NOT SPECIFIC TO ENGINES, MACHINES OR APPARATUS PROVIDED FOR ELSEWHERE; STANDS; SUPPORTS
    • F16M1/00—Frames or casings of engines, machines or apparatus; Frames serving as machinery beds
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/02—Casings; Cabinets ; Supports therefor; Mountings therein

Definitions

  • the present invention relates to an ultrasonic sensor and, more particularly, to an ultrasonic sensor for converting a received ultrasonic wave into an electric signal or an electric signal into an ultrasonic wave so as to transmit it.
  • an ultrasonic sensor is mounted in the vehicle, which may include an automobile.
  • the ultrasonic sensor receives a reflected wave of an ultrasonic wave harmless to a human body, which is transmitted from the ultrasonic sensor, so as to measure the position of or a distance from an object present in the vicinity of the automobile, a two-dimensional shape, or a three-dimensional shape of the object and the like.
  • An ultrasonic sensor is mounted in a rear part of an automobile.
  • a device generally called “a back sonar,” is used while reversing the automobile into a parking space to avoid the collision with an object.
  • the “back sonar” is for detecting the object, which may include a human or another obstacle, present behind the automobile.
  • a piezoelectric or a capacitive (condenser) ultrasonic sensor fabricated by employing a Micro Electro Mechanical Systems (MEMS) technique is known.
  • a technique of juxtaposing a plurality of ultrasonic sensor elements has been disclosed as a piezoelectric ultrasonic sensor employing the MEMS technique.
  • Each of the ultrasonic sensor elements is composed of a piezoelectric sensor, which includes a ferroelectric member interposed between a pair of electrodes.
  • the piezoelectric sensor has a predetermined resonance frequency to detect an ultrasonic wave.
  • Such a device is disclosed in Japanese Patent Laid-Open Publication No. 2003-284182.
  • the ultrasonic sensor disclosed in the above publication includes a piezoelectric element, which serves as a piezoelectric sensor, formed on a semiconductor chip having a “Silicon On Insulator” (SOI) structure.
  • the piezoelectric element includes a thin film made of a PZT (lead zirconate titanate) ceramic corresponding to a ferroelectric material interposed between two thin electrode layers including an upper electrode layer and a lower electrode layer.
  • each of the electrode layers and the PZT ceramic thin film have a low mechanical strength.
  • the capacitive ultrasonic sensor using the MEMS technique includes: a fixed electrode layer formed on a semiconductor chip; and a thin movable electrode layer provided on the fixed electrode layer through a gap.
  • the fixed electrode layer and the movable electrode layer form a capacitive element.
  • the movable electrode layer has a low mechanical strength. Therefore, there arises a problem that the movable electrode layer is vulnerable to damage upon application of an external force to the movable electrode layer so that the capacitive electrode is likely to be broken.
  • the conventional piezoelectric or capacitive ultrasonic sensors fabricated by employing the MEMS technique are likely to be damaged under the application of an external force. Therefore, it is difficult to mount the conventional ultrasonic sensor in an automobile as external equipment.
  • the present invention was devised to solve the above-described and other problems and to provide a robust ultrasonic sensor that that can withstand the application of an external force.
  • An ultrasonic sensor includes a plurality of conversion means and a protection means.
  • the plurality of conversion means are for converting one of a received ultrasonic wave and an electric signal to the other of the electric signal and the ultrasonic wave for transmission.
  • the plurality of conversion means are juxtaposed.
  • the protection means is for protecting each of the conversion means.
  • An ultrasonic sensor is characterized in that the protection means includes a protective film provided in front of each of the plurality of conversion means and a first gap is provided between the protective film and the conversion means.
  • An ultrasonic sensor is characterized in that the first gap is filled with a filler selected from a liquid, a sol, and a gel.
  • An ultrasonic sensor is characterized in that the ultrasonic sensor includes a vent hole for bringing the first gap and exterior into communication with each other.
  • An ultrasonic sensor includes separation means for separating the conversion means and the first gap located in front of the conversion means and the protective film for each of the conversion means.
  • An ultrasonic sensor includes a housing member for housing each of the plurality of the conversion means therein; a second gap surrounded by the housing member and the conversion means; and a vent hole for bringing the second gap and exterior into communication with each other.
  • An ultrasonic sensor is characterized in that the conversion means is a transmission element for converting an electric signal into an ultrasonic wave for transmission.
  • An ultrasonic sensor includes a housing member for housing each of the plurality of conversion means therein; and a second gap corresponding to a sealed space surrounded by the housing member and the conversion means.
  • An ultrasonic sensor is characterized in that the second gap is filled with a filler selected from a liquid, a sol, and a gel.
  • An ultrasonic sensor is characterized in that each of the conversion means is a receiving element for converting a received ultrasonic wave into an electric signal.
  • An ultrasonic sensor includes a transfer member for independently connecting each of the conversion means and the protective film with each other for each of the conversion means.
  • An ultrasonic sensor includes a protective member attached to and fixed in front of each of the plurality of conversion means, the protective member being provided for each of the conversion means, a clearance being provided between the protective members, and the clearance serving to separate the protective members from each other for each of the conversion means.
  • An ultrasonic sensor includes an acoustic horn provided in front of each of the plurality of conversion means, wherein the acoustic horn is provided for each of the conversion means so as to have a gradually increasing sectional area from a throat provided in front of each of the conversion means toward an opening.
  • An ultrasonic sensor is characterized in that each of the conversion means is formed on a surface of a semiconductor substrate, the surface side of the semiconductor substrate being regarded as the front side of each of the conversion means so as to serve as any one of a receiving surface and a transmission surface of an ultrasonic wave, a bonding wire is connected to the surface side of the semiconductor substrate, and each of the conversion means is surface-mounted on a sensor substrate by a wire bonding method through the bonding wire.
  • An ultrasonic sensor is characterized in that each of the conversion means is formed on a surface of a semiconductor substrate, a bottom side of the semiconductor substrate being regarded as the front side of each the conversion means so as to serve as any one of a receiving surface and a transmission surface of an ultrasonic wave, a bump is connected to the surface side of the semiconductor substrate, and each of the conversion means is surface-mounted on a sensor substrate by flip-chip connection through the bump.
  • An ultrasonic sensor is characterized in that each of the conversion means is any one of a piezoelectric conversion type and a capacitive conversion type.
  • the conversion means is composed of the receiving element for converting the received ultrasonic wave into the electric signal or the electric signal into the ultrasonic wave so as to transmit it.
  • the plurality of conversion means are juxtaposed.
  • the protection means for protecting each of the conversion means is provided. Therefore, even if each of the conversion means has a low mechanical strength, it becomes possible to prevent the conversion means from being damaged so as to be hardly broken. As a result, a robust ultrasonic sensor can be obtained.
  • the protective film is provided in front of the plurality of the conversion means, and the first gap is provided between the protective film and the conversion means. Therefore, even if an external force is applied to the ultrasonic sensor, the external force is applied only to the protective film but not directly to each of the conversion means.
  • the ultrasonic sensor according to the second aspect of the present invention can be mounted in an automobile as external equipment without any modification. If the ultrasonic sensor is to be mounted in an automobile as external equipment of an automobile, it is necessary to use a highly weather-resistant material for the protective film. Examples of such a material include various metals (such as an aluminum alloy), various synthetic resins, glasses, rubbers, and the like.
  • an acoustic impedance of the filler selected from a liquid, a sol, and a gel filling the first gap is brought close to that of the protective film.
  • the acoustic impedance of a material corresponds to a product of a density of the material and a propagation acoustic speed. Then, as a difference in acoustic impedance between materials becomes larger, the propagation characteristic of an acoustic wave is degraded. Specifically, as a difference in acoustic impedance between the filler in the first gap and the protective film becomes greater, an ultrasonic wave is reflected by the protective film so as to be less likely to propagate to the filler.
  • a synthetic resin film is used as the protective film
  • a sol obtained by dispersing fine particles of the synthetic resin in a liquid or a polymer gel made of the synthetic resin is used as the filler.
  • the filler is required not to affect the conversion means. Examples of the filler meeting such a requirement include a silicon gel, a fluorine gel, and the like.
  • the oscillation of the protective film does not satisfactorily propagate to each of the conversion means because the gas has an acoustic impedance extremely smaller than that of the protective film. Accordingly, there is a possibility that receiving sensitivity is lowered when each of the conversion means is used as a receiving element.
  • each of the conversion means is used as a transmission element, the acoustic impedance of the filler selected from a liquid, a sol, and a gel filling the first gap is brought close to that of the protective film. As a result, the propagation of oscillation of the transmission element through the filler to the protective film can be ensured, thereby enhancing a transmission output of the transmission element.
  • the oscillation of the transmission element does not satisfactorily propagate to the protective film because the acoustic impedance of the gas is extremely smaller than that of the protective film. As a result, there is a possibility that a transmission output of the transmission element becomes low.
  • the first gap is filled with the filler such as a liquid, a sol, or a gel
  • the filler such as a liquid, a sol, or a gel
  • the filler in the first gap contains air bubbles, it is possible to remove the air bubbles from the first gap through the vent hole to the exterior.
  • the filler in the first gap contains air bubbles, the air bubbles make it hard to propagate the oscillation of the protective film to each of the conversion means.
  • the fourth aspect of the present invention since the air bubbles are removed through the vent hole, it becomes possible to completely fill the first gap with the filler. Therefore, if each of the conversion means is used as a receiving element, the receiving sensitivity can be prevented from being lowered by the presence of air bubbles contained in the filler in the first gap.
  • each of the conversion means is used as a transmission element, it becomes possible to completely fill the first gap with the filler because the air bubbles contained in the filler in the first gap are removed through the vent hole. In this manner, the propagation of oscillation of the transmission element through the filler to the protective film can be ensured to prevent the transmission output of the transmission element from being lowered.
  • the oscillation of a single protective film separated by the separation means propagates only to the conversion means through the first gap situated below the protective film but not to the other conversion means.
  • the propagation of an ultrasonic wave to each of the conversion means can be performed in a completely separate manner. Therefore, a crosstalk characteristic of each of the conversion means can be prevented from being degraded.
  • a plurality of adjacent conversion means can be grouped into one. Separation means may be provided for each group of the conversion means so as to separate the corresponding group from the other groups.
  • the separation means has to surely block the oscillation of the protective film, the first gap, and the conversion means, which are vertically provided so as to be grouped into one, so that the oscillation does not propagate to members of the other adjacent groups.
  • a material having a high oscillation blocking property is required to be used for the separation means.
  • the material include rubbers.
  • the second gap forms a sealed space. Air filling the sealed space acts as a spring so as to apply a damping force due to air onto the back face side of each of the conversion means. As a result, the free oscillation of each of the conversion means is inhibited.
  • each of the conversion means is capable of freely oscillating.
  • each of the conversion means is used as a transmission element, air passes through the vent hole of the second gap. Therefore, no damping force due to air is applied to the back face side of a transmission surface of the transmission element for transmitting an ultrasonic wave. As a result, the transmission surface can freely oscillate without inhibiting the oscillation. Therefore, the transmission output of the transmission element can be increased.
  • the number, the position, the shape, and the size of the vent hole may be set by experimentally finding their optimal values in a cut-and-try method.
  • the resonance value Q of the transmission element and the transmission output are positively correlated with each other.
  • the resonance value Q increases, the transmission output becomes greater.
  • the transmission element including a piezoelectric element or a capacitive element fabricated by employing the MEMS technique is not suitable for the transmission element because of its small transmission output of an ultrasonic wave. Therefore, such a transmission element is required to increase the transmission output as much as possible.
  • the seventh aspect of the present invention can demonstrate the functions and effects of the sixth aspect particularly when the aspect is embodied as the transmission element fabricated by employing the MEMS technique.
  • air filling the second gap corresponding to the sealed space acts as a spring so as to apply a damping force due to air onto the back face side of each of the conversion means.
  • each of the conversion means is used as a receiving element, the receiving sensitivity is lowered because the oscillation of each of the conversion means is inhibited.
  • the diaphragm of the conversion means by filling the second gap with a material for suppressing the oscillation of the diaphragm of the conversion means (for example, a liquid, a sol, a gel, or the like), the diaphragm of the conversion means can be prevented from excessively oscillating to be broken.
  • a material for suppressing the oscillation of the diaphragm of the conversion means for example, a liquid, a sol, a gel, or the like
  • the resonance value Q of the receiving element and the receiving sensitivity are positively correlated with each other.
  • the receiving sensitivity becomes greater.
  • a plurality of receiving elements have a fluctuation in primary resonance frequency due to a fabrication process.
  • the receiving sensitivity is increased.
  • the receiving sensitivity exhibits a steep characteristic with respect to a change in frequency, the receiving sensitivity suddenly drops at a frequency offset from the primary resonance frequency even if the offset is slight.
  • the receiving sensitivity becomes correspondingly low.
  • the receiving sensitivity exhibits a gentle characteristic with respect to a change in frequency, the receiving sensitivity does not greatly drop even at a frequency far from the primary resonance frequency.
  • the receiving element comprising a piezoelectric element or a capacitive element fabricated by employing the MEMS technique is suitable for a receiving element because of its high receiving sensitivity of an ultrasonic wave. Therefore, it is necessary to increase the receiving sensitivity over a broad frequency range as much as possible rather than to increase the receiving sensitivity at the primary resonance frequency.
  • the tenth aspect of the present invention can demonstrate the functions and effects of the eighth aspect particularly when the aspect is embodied as a receiving element fabricated by employing the MEMS technique.
  • the resonance value Q of the diaphragm of the conversion means can be reduced as compared with the case where the second gap is filled with air.
  • the oscillation of the protective film propagates to each of the conversion means through each of the transfer members.
  • the transfer member is provided for each of the conversion means, the oscillation of an arbitrary transfer member never propagates to the other transfer members.
  • the reception or transmission of an ultrasonic wave can be performed in a separated manner for each of the conversion means, a crosstalk characteristic of each of the conversion means can be prevented from being degraded.
  • each of the transfer members is brought close to that of the protective film.
  • the propagation of oscillation of the protective film to each of the conversion means can be ensured, thereby enhancing the receiving sensitivity in the case where each of the conversion means is used as a receiving element.
  • each of the transfer members is brought close to that of the conversion means.
  • the propagation of oscillation of each of the transfer members to each of the conversion means can be ensured, thereby enhancing the receiving sensitivity in the case where each of the conversion means is used as a receiving element.
  • the transfer member be made of the same material as that of the protective film or the conversion means.
  • each of the conversion means is used as a transmission element, the propagation of oscillation of the transfer member to the protective film can be ensured by bringing the acoustic impedance of the transfer member close to that of the protective film. As a result, the transmission output of the transmission element can be increased.
  • each of the conversion means is used as a transmission element, the propagation of oscillation of the transmission element to the transfer member can be ensured by bringing the acoustic impedance of the transfer member close to that of the transmission element. As a result, the transmission output of the transmission element can be increased.
  • each of the conversion means is used as a receiving element, the oscillation of the protective member propagates to the receiving element when an ultrasonic wave oscillates the protective member because the protective film is attached and fixed in front of the receiving element.
  • each of the conversion means is used as a transmission element
  • the oscillation of the transmission element propagates to the protective member when the transmission element oscillates because the protective member is attached and fixed in front of the transmission element.
  • the protective member oscillates to transmit an ultrasonic wave.
  • each of the conversion means is reinforced by the protective member, each of the conversion means can be prevented from being damaged so as to be hardly broken even if an external force is applied to the ultrasonic sensor. As a result, a robust ultrasonic sensor can be obtained.
  • the ultrasonic sensor according to the twelfth aspect of the present invention can be mounted as external equipment of an automobile without any modification. If the ultrasonic sensor is mounted as external equipment of an automobile, it is necessary to use a highly weather-resistant material for the protective member. Examples of the material include various metals (such as an aluminum alloy), various synthetic resins, glasses, rubbers, and the like.
  • any method for example, thermal welding, ultrasonic welding, bonding with an adhesive, and the like may be used.
  • an acoustic horn is provided for each of the conversion means.
  • each of the conversion means can be imparted with directivity of a receiving direction or a transmitting direction of an ultrasonic wave.
  • each of the acoustic horns has acute directivity on its horn axis. Therefore, by forming the acoustic horns to have the same size and shape, the directivity of each of the conversion means can be the same if the horn axes of the acoustic horns are set in the same direction. Moreover, in the case where the horn axes of the acoustic hones are set to be in arbitrary different directions by changing the size and shape of each of the acoustic horns, the directivity of each of the conversion means can also be set in an arbitrary direction.
  • a horn wall member of each of the acoustic horns is required to be formed of a material having enough strength to hardly cause oscillation by an ultrasonic wave.
  • the material include various metals, various synthetic resins, and the like.
  • the ultrasonic sensor formed by surface-mounting each of the conversion means on a sensor substrate by using wire bonding can be obtained.
  • each of the conversion means and the sensor substrate are connected and fixed to each other through a bump. Therefore, since it can be ensured to keep the electric connection between each of the conversion means and the sensor substrate, the reliability of the ultrasonic sensor can be enhanced while extending a lifetime of the ultrasonic sensor.
  • the fabrication cost for surface-mounting each of the conversion means onto the sensor substrate can be reduced as compared with the case where the wire bonding is employed.
  • each of the conversion means is used as a receiving element
  • a bonding wire is not provided above the receiving surface of an ultrasonic wave and therefore no obstacle is present in front of the receiving surface. Therefore, the ultrasonic wave is not inhibited from getting to the receiving surface, thereby enhancing the receiving sensitivity of the receiving element.
  • the bonding wire is not cut by an ultrasonic wave received by the receiving element.
  • each of the conversion means is used as a transmission element
  • a bonding wire is not provided above the transmission surface of the transmission element and therefore no obstacle is present in front of the transmission surface. Therefore, the ultrasonic wave is not inhibited from being transmitted from the transmission surface, thereby enhancing the transmission output of the transmission element.
  • the bonding wire is not cut by an ultrasonic wave transmitted from the transmission element.
  • the ultrasonic sensor can be reduced in size as well as in weight.
  • the functions and effects of the thirteenth aspect of the invention can be easily obtained without providing the acoustic horn as an independent member.
  • the acoustic horn is not required to be provided as an independent member, the fabrication cost can be reduced.
  • the ultrasonic sensor can be reduced in size as well as in weight.
  • a piezoelectric or capacitive ultrasonic sensor can be obtained.
  • FIG. 1 is a cross-sectional side view of a receiving section of an ultrasonic sensor according to a first embodiment of the present invention
  • FIG. 2 is an enlarged cross-sectional side view of a piezoelectric receiving element of the receiving section of FIG. 1 ;
  • FIG. 3 is a perspective view of a first ultrasonic sensor according to the principles of the present invention.
  • FIG. 4 is a cross-sectional side view of a receiving section of an ultrasonic sensor according to a second embodiment of the present invention.
  • FIG. 5 is a cross-sectional side view of a receiving section of an ultrasonic sensor according to a third embodiment of the present invention.
  • FIG. 6 is a cross-sectional side view of a receiving section of an ultrasonic sensor according to a fourth embodiment of the present invention.
  • FIG. 7 is a cross-sectional side view of a receiving section of an ultrasonic sensor according to a fifth embodiment of the present invention.
  • FIG. 8 is a cross-sectional side view of a receiving section of an ultrasonic sensor according to a sixth embodiment of the present invention.
  • FIGS. 9A and 9B are cross-sectional side views of a receiving section of an ultrasonic sensor according to a seventh embodiment of the present invention.
  • FIG. 10 is a cross-sectional side view of a receiving section of an ultrasonic sensor according to an eighth embodiment of the present invention.
  • FIG. 11 is an enlarged cross-sectional side view of a capacitive receiving element adapted for use in any one of the receiving sections in the first through eighth embodiments of the present invention.
  • FIG. 12 is a perspective view of a second ultrasonic sensor according to the principles of the present invention.
  • FIG. 13 is a cross-sectional side view of the receiving section of FIG. 4 and a transmission section of the ultrasonic sensor of FIG. 12 ;
  • FIG. 14 is a cross-sectional side view of the receiving section of FIG. 5 and a transmission section of the ultrasonic sensor of FIG. 12 ;
  • FIG. 15 is a cross-sectional side view of the receiving section of FIG. 8 and a transmission section of the ultrasonic sensor of FIG. 12 ;
  • FIGS. 16A and 16B are cross-sectional side views of the receiving section of FIGS. 9A and 9B and a transmission section of the ultrasonic sensor of FIG. 12 ;
  • FIG. 17 is a cross-sectional side view of the receiving section of FIG. 10 and a transmission section of the ultrasonic sensor of FIG. 12 ;
  • FIG. 18 is a cross-sectional side view of a receiving section of an ultrasonic sensor according to a ninth embodiment of the present invention.
  • FIG. 19 is an enlarged cross-sectional side view of a piezoelectric receiving element of the receiving section of FIG. 18 ;
  • FIG. 20 is a perspective view of a third ultrasonic sensor according to the principles of the present invention.
  • FIG. 21 is a cross-sectional side view of a receiving section according to a tenth embodiment of the present invention adapted for use in the ultrasonic sensor of FIG. 20 ;
  • FIG. 22 is a cross-sectional side view of a receiving section according to an eleventh embodiment of the present invention adapted for use in the ultrasonic sensor of FIG. 20 ;
  • FIG. 23 is a perspective view of a fourth ultrasonic sensor according to the principles of the present invention.
  • FIGS. 24A and 24B are graphs showing a resonance characteristic corresponding to the relation between a resonance value of a diaphragm and a frequency according to the principles of the present invention.
  • FIG. 25 is a cross-sectional side view of a receiving section according to an twelfth embodiment of the present invention adapted for use in the ultrasonic sensor of FIG. 20 ;
  • FIG. 26 is a cross-sectional side view of a first alternative receiving section of the twelfth embodiment of the present invention.
  • FIG. 27 is a cross-sectional side view of a second alternative receiving section and a transmission section of the twelfth embodiment of the present invention.
  • FIG. 28 is a cross-sectional side view of a receiving section according to a thirteenth embodiment of the present invention adapted for use in the ultrasonic sensor of FIG. 20 ;
  • FIG. 29 is a cross-sectional side view of a first alternative receiving section of the thirteenth embodiment.
  • FIG. 30 is a cross-sectional side view of a second alternative receiving section according to the thirteenth embodiment and the transmission section adapted for use in the ultrasonic sensor of FIG. 23 ;
  • FIG. 31 is a cross-sectional side view of a receiving section according to a fourteenth embodiment of the present invention adapted for use in the ultrasonic sensor of FIG. 20 ;
  • FIG. 32 is a cross-sectional side view of a first alternative receiving section of the fourteenth embodiment of the present invention adapted for use in the ultrasonic sensor of FIG. 20 ;
  • FIG. 33 is a cross-sectional side view of a second alternative receiving section of the fourteenth embodiment and a transmission section adapted for use in the ultrasonic sensor of FIG. 23 ;
  • FIG. 34 is an enlarged cross-sectional side view of a capacitive receiving element adapted for use in any one of the receiving sections of the ninth to the fourteenth embodiments including the alternatives to these embodiments;
  • FIG. 35 is a cross-sectional side view of the receiving section and the transmission section of the ninth embodiment adapted to the ultrasonic sensor of FIG. 23 ;
  • FIG. 36 is a cross-sectional side view of the receiving section and the transmission section of the twelfth embodiment adapted to the ultrasonic sensor of FIG. 23 ;
  • FIG. 37 is a cross-sectional side view of the receiving section and the transmission section of the thirteenth embodiment adapted to the ultrasonic sensor of FIG. 23 ;
  • FIG. 38 is a cross-sectional side view of the receiving section and the transmission section of the fourteenth embodiment adapted to the ultrasonic sensor of FIG. 23 .
  • FIG. 1 is a cross-sectional side view showing a receiving section 10 in an ultrasonic sensor M according to Embodiment 1.
  • the receiving section 10 includes a plurality of piezoelectric receiving elements 11 arranged in an array. In an example shown in FIG. 1 , a cross-sectional side view of three receiving elements 11 is shown.
  • Each of the receiving elements 11 is formed on a single-crystalline silicon substrate (a single-crystalline silicon chip) 12 having an SOI structure.
  • the substrate 12 is housed within a housing member 13 having a rectangular parallelepiped box shape with an upper open end. Moreover, an outer circumferential end of the substrate 12 is attached and fixed to an inner wall of the housing member 13 by an appropriate method (for example, thermal welding, ultrasonic welding, bonding with an adhesive or the like) so as to air-seal a connection part between the outer circumferential end of the substrate 12 and the housing member 13 .
  • an appropriate method for example, thermal welding, ultrasonic welding, bonding with an adhesive or the like
  • Each of the receiving elements 11 is located so that a receiving surface 11 a for receiving an ultrasonic wave is oriented toward an opening 13 a of the housing member 13 .
  • a protective film 14 for closing the opening 13 a is attached over the opening 13 a of the housing 13 .
  • the protective film 14 is provided in front of the receiving elements 11 .
  • An outer circumferential end of the protective film 14 is attached and fixed to an inner circumferential end of the opening 13 a of the housing member 13 by the above-described appropriate method so as to air-seal a connection part between the outer circumferential end of the protective film 14 and the housing member 13 .
  • the protective film 14 is a thin film made of a material that is likely to be oscillated by an ultrasonic wave. Although the material of the protective film 14 transmits an ultrasonic wave without refraction, it does not transmit air, dust, water and the like.
  • a gap S is provided between the protective film 14 and the substrate 12 .
  • the gap S is filled with a gas, a liquid, a sol, a gel or the like.
  • a gap R surrounded by the back face side (the bottom face side) of the substrate 12 and the housing member 13 is filled with air.
  • FIG. 2 is an enlarged cross-section side view showing one piezoelectric receiving element 11 .
  • a through hole 12 a passing through the substrate 12 is formed in the substrate 12 .
  • an insulating layer 21 On a surface of the substrate 12 , an insulating layer 21 , a silicon active layer 22 , and an insulating layer 23 are formed in this order. Each of the layers 22 and 23 is formed to close the upper opening of the through hole 12 a.
  • a lower electrode layer 24 On a surface of the insulating layer 23 situated above (in front of) the through hole 12 a , a lower electrode layer 24 , a thin film layer 25 made of a ferroelectric (for example, PZT or the like), and an upper electrode layer 26 are formed in this order.
  • a ferroelectric for example, PZT or the like
  • An insulating layer 27 is formed around the layers 24 to 26 . Surfaces of the insulating layer 27 and the upper electrode layer 26 (a device surface) are evened.
  • a bonding wire (a lead wire) 28 is connected to the lower electrode layer 24 , whereas a bonding layer 29 is connected to the upper electrode layer 26 .
  • a piezoelectric element (a piezoelectric sensor) E having a structure in which the ferroelectric thin film layer 25 is sandwiched between the two thin electrode layers 24 and 26 is formed.
  • the receiving element 11 includes the piezoelectric element E fabricated by employing the MEMS technique.
  • a receiving surface 11 a of the receiving element 11 is formed by the surface of the upper electrode layer 26 .
  • the through hole 12 a is provided so as to facilitate the oscillation of a diaphragm composed of the layers 22 to 26 .
  • FIG. 3 is a perspective view showing the ultrasonic sensor M.
  • the ultrasonic sensor M is composed of a hybrid IC (Integrated Circuit) including: a receiving section 10 ; a transmission section 31 ; a sensor substrate 32 ; and electrode pads 33 .
  • a hybrid IC Integrated Circuit
  • the sensor substrate 32 is a printed wiring board.
  • a plurality of electrode pads 33 are formed on a surface of the sensor substrate 32 formed of an insulating plate material while the receiving section 10 and the transmission section 31 corresponding to chip parts are attached and fixed thereto.
  • a tip of each of the bonding wires 28 and 29 led from each of the receiving elements 11 in the receiving section 10 is connected to each of the electrode pads 33 .
  • the receiving section 10 is constituted by nine receiving elements 11 arranged 3 by 3.
  • the transmission section 31 has the same structure as that of the receiving section 10 .
  • the transmission section 31 includes a single piezoelectric transmission element having the same structure as that of the receiving element 11 .
  • the thin film layer 25 oscillates due to the piezoelectric effect to produce an ultrasonic wave in accordance with input signals applied from the electrode layers 24 and 26 to the thin film layer 25 made of a ferroelectric.
  • the receiving surface 11 a of the receiving element 11 acts as a transmission surface for transmitting the ultrasonic wave from the transmission element.
  • the transmission element of the transmission section 31 converts an electric signal into an ultrasonic wave so as to transmit it.
  • the transmission section 31 transmits an ultrasonic wave in accordance with an input signal from the exterior.
  • a reflection sound generated by the ultrasonic wave reflected by an object to be detected is received by each of the receiving elements 11 in the receiving section 10 .
  • each of the receiving elements 11 in the receiving section 10 converts the received ultrasonic wave into an electric signal.
  • the ultrasonic wave transmitted from the transmission section 31 and the ultrasonic wave received by each of the receiving elements 11 in the receiving section 10 are compared with each other so as to obtain an acoustic pressure difference, a time difference, and a phase difference between them.
  • the position of the object to be detected, a distance between the ultrasonic sensor M and the object to be detected, a two-dimensional or three-dimensional shape of the object to be detected and the like can be measured based on the obtained differences.
  • the protective film 14 is provided in front of the substrate 12 on which the receiving elements 11 are formed.
  • the gap S is provided between the protective film 14 and the substrate 12 .
  • each of the thin layers 22 to 26 has a low mechanical strength, each of the layers 22 to 26 can be prevented from being damaged so as to be unlikely to break the receiving section 10 . As a result, the robust receiving section 10 can be obtained.
  • the transmission element of the transmission section 31 has the same structure as that of the receiving element 11 , each of the layers 22 to 26 can be prevented from being damaged so that the transmission section 31 is hardly broken. As a result, the robust transmission section 31 can be obtained.
  • the ultrasonic sensor M including the receiving section 10 and the transmission section 31 can be mounted as external equipment of an automobile without any modification. If the ultrasonic sensor M is to be mounted as external equipment of an automobile, it is necessary to use a highly weather-resistant material for the protective film 14 .
  • the material include various metals (such as an aluminum alloy), various synthetic resins, glasses, rubbers, and the like.
  • the gap S between the protective film 14 and the substrate 12 is filled with a filler selected from a liquid, a sol and a gel
  • a filler selected from a liquid, a sol and a gel
  • an acoustic impedance of the filler is brought close to that of the protective film 14 , so that it becomes possible to propagate the oscillation of the protective film 14 through the filler to each of the receiving elements 11 .
  • the receiving sensitivity of each of the receiving elements 11 can be enhanced.
  • the acoustic impedance of a material is a product of a density of the material and a propagation acoustic speed. Then, as a difference in acoustic impedance between materials becomes larger, the propagation characteristic of an acoustic wave is degraded. Specifically, as a difference in acoustic impedance between the filler in the gap S and the protective film 14 becomes greater, an ultrasonic wave is reflected by the protective film 14 so as be less likely to propagate to the filler.
  • a synthetic resin film is used as the protective film 14 , a sol obtained by dispersing fine particles of the synthetic resin in a liquid or a polymer gel made of the synthetic resin is used as the filler.
  • the filler is required not to affect the receiving elements 11 . Examples of the filler meeting such a requirement include a silicon gel, a fluorine gel, and the like.
  • the filler is injected into the gap S while removing air from the gap S.
  • the protective film 14 may be attached onto the housing member 13 .
  • the substrate 12 is rotated so as to form a thin film made of the filler on the surface of the substrate 12 by spin coating. Subsequently, the substrate 12 may be housed within the housing member 13 .
  • the oscillation of the protective film 14 does not satisfactorily propagate to the receiving elements 11 because the gas has an acoustic impedance extremely smaller than that of the protective film 14 . Accordingly, there is a possibility that the receiving sensitivity of each of the receiving elements 11 is lowered.
  • the oscillation of the protective film 14 is less likely to propagate to the receiving elements 11 if air remains in the gap S. Therefore, it is desirable to completely remove air from the gap S so as to fill the gap S with the filler.
  • the gap S between the protective film 14 and the substrate 12 is filled with the filler selected from a liquid, a sol and a gel, the propagation of oscillation of the transmission element through the filler to the protective film 14 can be ensured by bringing the acoustic impedance of the filler close to that of the protective film 14 because the transmission element in the transmission section 31 has the same structure as that of the receiving element 11 . As a result, a transmission output of the transmission element can be enhanced.
  • the oscillation of the transmission element does not satisfactorily propagate to the protective film 14 because the acoustic impedance of the gas is extremely smaller than that of the protective film 14 . Therefore, there is a possibility that a transmission output of the transmission element becomes low.
  • the gap S is filled with the filler such as a liquid, a sol and a gel
  • the filler such as a liquid, a sol and a gel
  • the ultrasonic sensor includes the receiving section 10 including nine receiving elements 11 (piezoelectric elements E).
  • the number of the receiving elements 11 constituting the receiving section 10 affects the accuracy of the measurement (the measurement of position, a distance and a shape) of the object to be detected; as the number of the receiving elements 11 is increased, the accuracy can be enhanced.
  • An interval between the receiving elements 11 is required to be set shorter than a wavelength of the ultrasonic wave transmitted from the transmission section 31 .
  • the interval between the receiving elements 11 also affects the measurement accuracy.
  • the number of and the interval between the receiving elements 11 can be set by experimentally finding their optimal values in a cut-and-try method in accordance with the required measurement accuracy.
  • the ultrasonic sensor M For example, if only the directional position of the object to be detected with respect to the ultrasonic sensor M is to be measured, several receiving elements 11 are satisfactory. However, if a precise two-dimensional shape of the object to be detected is measured, it is necessary to provide several tens to several hundreds of the receiving elements 11 . Furthermore, if a precise three-dimensional shape of the object to be detected is measured, a larger number of the receiving elements 11 than the number needed for two-dimensional shape measurement are required.
  • the arrangement of the transmission elements constituting the transmission section 31 is appropriately determined so as to adjust the directivity of a transmission direction of an ultrasonic wave.
  • the number and the arrangement of the transmission elements constituting the transmission section 31 can be set by experimentally fining their optimal values in a cut-and-try method in accordance with the required transmission output and directivity.
  • FIG. 4 is a cross-sectional side view showing a receiving section 40 in the ultrasonic sensor M according to Embodiment 2.
  • the receiving section 40 according to Embodiment 2 differs from the receiving section 10 in Embodiment 1 only in that the protective film 14 is replaced by a thin-plate like protective member 41 attached and fixed onto the receiving surface 11 a of each of the receiving elements 11 .
  • the protective member 41 is attached to the front side of each of the receiving elements 11 .
  • a clearance K is provided between the protective members 41 of the respective receiving elements 11 .
  • the clearance K separates the protective members 41 for each of the receiving elements 11 .
  • the structure of the ultrasonic sensor M according to Embodiment 2 is obtained by replacing the receiving section 10 in the ultrasonic sensor M shown in FIG. 3 according to Embodiment 1 with the receiving section 40 .
  • Embodiment 2 the following functions and effects can be obtained in addition to the same functions and effects described in [1-3] and [1-4] of Embodiment 1 above.
  • the thin plate-like protective member 41 is attached and fixed to the receiving surface 11 a of each of the receiving elements 11 . Therefore, when the protective member 41 is oscillated by an ultrasonic wave, the oscillation of the protective member 41 propagates to each of the layers 22 to 26 (not shown in FIG. 4 ; see FIG. 2 ) on the receiving surface 11 a . As a result, the thin film layer 25 made of a ferroelectric oscillates to generate an electric signal due to a piezoelectric effect.
  • each of the thin layers 22 to 26 on the receiving surface 11 a are reinforced with the protective member 41 , each of the thin layers 22 to 26 can be prevented from being damaged so as to be unlikely to break the receiving section 40 even if an external force is applied to the receiving section 40 of the ultrasonic sensor M. As a result, the robust receiving section 40 can be obtained.
  • the transmission section 31 is made to have the same structure as that of the receiving section 40 so that the thin plate-like protective member 41 is attached and fixed to the transmission surface of the transmission element, the oscillation of the thin film layer 25 propagates to the protective member 41 when the thin film layer 25 is oscillated by the piezoelectric effect. Then, the protective member 41 is oscillated in turn to transmit the ultrasonic wave.
  • each of the thin layers 22 to 26 on the transmission surface of the transmission element are reinforced by the protective member 41 , each of the thin layers 22 to 26 can be prevented from being damaged so as to be unlikely to break the transmission section 31 even if an external force is applied to the transmission section 31 of the ultrasonic sensor M. As a result, the robust transmission section 31 can be obtained.
  • the ultrasonic sensor M including the receiving section 40 and the transmission section 31 can be mounted as external equipment of an automobile without any modification. If the ultrasonic sensor M is to be mounted as external equipment of an automobile, it is necessary to use a highly weather-resistant material as a material of the protective member 41 . Examples of such a material include various metals (such as an aluminum alloy), various synthetic resins, glasses, rubbers, and the like.
  • any method for example, thermal welding, ultrasonic welding, bonding with an adhesive and the like may be used.
  • the clearance K is provided between the protective members 41 of the respective receiving elements 11 .
  • the clearance K serves to separate the protective members 41 for each of the receiving elements 11 . Therefore, the oscillation of one protective member 41 propagates only to the receiving element 11 to which the protective member 41 is attached and fixed but not to the other receiving elements 11 through the adjacent protective member 41 .
  • Embodiment 2 since an ultrasonic wave can be received by each of the receiving elements 11 in a completely separate manner, a crosstalk characteristic of each of the receiving elements 11 can be prevented from being degraded.
  • FIG. 5 is a cross-sectional side view showing a receiving section 50 in the ultrasonic sensor M according to Embodiment 3.
  • the receiving section 50 according to Embodiment 3 differs from the receiving section 10 according to Embodiment 1 merely in that separation members 51 and separation grooves 52 are provided.
  • each of the separation members 51 is embedded in each of the separation grooves 52 formed in the substrate 12 between the receiving elements 11 .
  • an upper end of each of the separation members 51 separates the gaps S and the protective films 14 for each of the receiving elements.
  • each of the separation members 51 is embedded into each of the separation grooves 52 formed in the substrate 12 between three receiving elements 11 A to 11 C.
  • the receiving elements 11 A to 11 C are separated from each other by the separation members 51 and the separation grooves 52 .
  • the gaps SA to SC and the protective films 14 A to 14 C situated above (in front of) the respective receiving elements 11 A to 11 C are also separated from each other by the separation members 51 for each of the receiving elements 11 A to 11 C.
  • the structure of the ultrasonic sensor M according to Embodiment 3 is obtained by replacing the receiving section 10 of the ultrasonic sensor M shown in FIG. 3 according to Embodiment 1 with the receiving section 50 .
  • Embodiment 3 the following functions and effects can be obtained in addition to the above-described functions and effects according to Embodiment 1.
  • the receiving elements 11 , and the gaps S and the protective films 14 situated above (in front of) the respective receiving elements 11 are separated by the separation members 51 and the separation grooves 52 for each of the receiving elements 11 . Therefore, the oscillation of one protective film 14 A obtained by the separation propagates only to the receiving element 11 A through the gap SA situated below the protective film 14 A but not to the other receiving elements 11 B and 11 C.
  • an ultrasonic wave can be received by each of the receiving elements 11 A to 11 C in a completely separate manner. Accordingly, a crosstalk characteristic of each of the receiving elements 11 A to 11 C can be prevented from being degraded.
  • a plurality of the receiving elements 11 adjacent to each other may be grouped into one.
  • the separation member 51 and the separation groove 52 may be provided for each group so as to separate the group from the other groups.
  • Each of the separation members 51 is required to surely block the oscillation of the protective film 14 A, the gap SA and the receiving element 11 A, which are vertically arranged to be grouped into one, so that the oscillation does not propagate to the members of the other adjacent groups (the protective films 14 B and 14 C, the gaps SB and SC, and the receiving elements 11 B and 11 C).
  • a material having a high oscillation blocking property is required to be used for each of the separation members 51 .
  • the material include rubbers.
  • FIG. 6 is a cross-sectional side view showing a receiving section 60 in the ultrasonic sensor M according to Embodiment 4.
  • the receiving section 60 according to Embodiment 4 differs from the receiving section 50 according to Embodiment 3 only in that a vent hole 61 for bringing the gap R and the exterior of the housing member 13 into communication with each other is formed in the bottom face of the housing member 13 below each of the receiving elements 11 .
  • the structure of the ultrasonic sensor M according to Embodiment 4 is obtained by replacing the receiving section 10 of the ultrasonic sensor M shown in FIG. 3 according to Embodiment 1 with the receiving section 60 .
  • a spacer may be provided between the receiving section 60 and the sensor substrate 32 , or a groove or a vent hole may be provided in the sensor substrate 32 at a position corresponding to each of the vent holes 61 .
  • the receiving sensitivity of each of the receiving elements 11 can be prevented from being lowered in addition to the above-described functions and effects according to Embodiment 3 because the oscillation of each of the layers 22 to 26 (not shown in FIG. 6 ; see FIG. 2 ) on the receiving surface 11 a of each of the receiving elements 11 is not inhibited.
  • the gap R surrounded by the substrate 12 and the housing member 13 becomes a sealed space.
  • air filling the sealed space acts as a spring so as to apply a damping force due to air to the back face side of the receiving surface 11 a of each of the receiving elements 11 . Therefore, there is a possibility that free oscillation of each of the layers 22 to 26 on the receiving surface 11 a is inhibited so as to lower the receiving sensitivity of each of the receiving elements 11 .
  • Embodiment 4 air passes through the vent holes 61 . Therefore, a damping force due to air is not applied to the back face side of the receiving surface 11 a of each of the receiving elements 11 . As a result, each of the layers 22 to 26 on the receiving surface 11 a is capable of freely oscillating.
  • the number, the arrangement, and the size and shape of the vent holes 61 can be determined by experimentally finding their optimal values in a cut-and-try method so as to obtain satisfactory functions and effects described above.
  • the transmission section 31 is made to have the same structure as that of the receiving section 60 and the vent holes 61 are provided for the housing member 13 of the transmission section 31 . Therefore, a damping force due to air is not applied onto the back face side of the transmission surface of the transmission element. As a result, since the oscillation is not inhibited so that each of the layers 22 to 26 on the transmission surface can freely oscillate, the transmission output of the transmission element can be enhanced.
  • FIG. 7 is a cross-sectional side view showing a receiving section 70 in the ultrasonic sensor M according to Embodiment 5.
  • the receiving section 70 according to Embodiment 5 differs from the receiving section 10 according to Embodiment 1 only in that a vent hole 71 for bringing the gap S and the exterior of the housing member 13 into communication with each other is provided through a side wall of the housing member 13 .
  • the structure of the ultrasonic sensor M according to Embodiment 5 is obtained by replacing the receiving section 10 of the ultrasonic sensor M shown in FIG. 3 according to Embodiment 1 with the receiving section 70 .
  • Embodiment 5 in addition to the above-described functions and effects of Embodiment 1, if a filler such as a liquid, a sol or a gel contains air bubbles when the gap S is filled with the filler, the air bubbles can be removed through the vent hole 71 to the exterior of the gap S.
  • a filler such as a liquid, a sol or a gel
  • the filler filling the gap S contains air bubbles, the air bubbles make it difficult to propagate the oscillation of the protective film 14 to the receiving elements 11 .
  • the air bubbles are removed through the vent hole 71 . Therefore, the gap S can be completely filled with the filler so as to prevent the receiving sensitivity of each of the receiving elements 11 from being lowered by the air bubbles contained in the filler filling the gap S.
  • the transmission section 31 is made to have the same structure as that of the receiving section 70 and the vent hole 71 is provided for the housing member 13 of the transmission section 31 .
  • the air bubbles contained in the filler of the gap S are removed through the vent hole 71 .
  • the gap S can be completely filled with the filler. In this manner, the oscillation of the transmission element is allowed to surely propagate through the filler to the protective film 13 so as to prevent the transmission output of the transmission element from being lowered.
  • FIG. 8 is a cross-sectional side view showing a receiving section 80 in the ultrasonic sensor M according to Embodiment 6.
  • the receiving section 80 according to Embodiment 6 differs from the receiving section 10 in Embodiment 1 only in that column-like transfer members 81 for independently connecting the receiving surfaces 11 a of the respective receiving elements 11 and the protective film 14 with each other for each of the receiving elements 11 are provided in the gap S.
  • the structure of the ultrasonic sensor M according to Embodiment 6 is obtained by replacing the receiving section 10 of the ultrasonic sensor M shown in FIG. 3 according to Embodiment 1 with the receiving section 80 .
  • Embodiment 6 the following functions and effects can be obtained in addition to the above-described functions and effects [1-1], [1-3], and [1-4] according to Embodiment 1.
  • the oscillation of the protective film 14 propagates through each of the transfer members 81 to each of the receiving elements 11 .
  • the transfer member 81 is provided for each of the receiving elements 11 , the oscillation of an arbitrary one of the transfer members 81 does not propagate to the other transfer members 81 . Therefore, an ultrasonic wave can be received by each of the receiving elements 11 in a separate manner. As a result, a crosstalk characteristic of each of the receiving elements 11 can be prevented from being degraded.
  • each of the transfer member 81 is brought close to that of the protective film 14 so as to surely propagate the oscillation of the protective film 14 to each of the transfer members 81 .
  • the receiving sensitivity of each of the receiving elements 11 can be enhanced.
  • the transfer member 81 of the same material as that of the protective film 14 or the upper electrode layer 26 .
  • the transmission section 31 is made to have the same structure as that of the receiving section 80 and the transfer member 81 for connecting the transmission surface of the transmission element and the protective film 14 with each other is provided, it becomes possible to surely propagate the oscillation of the transfer member 81 to the protective film 14 by bringing the acoustic impedance of the transfer member 81 close to that of the protective film 14 . As a result, the transmission output of the transmission element can be increased.
  • the transmission output of the transmission element can be increased.
  • Embodiment 6 it is the most desirable in Embodiment 6 to put the gap S in a vacuum state.
  • a gas having a small acoustic impedance or a highly vibration absorbent material for example, a gel having a high viscosity or the like is used as the filler.
  • FIGS. 9A and 9B are cross-sectional side views, each showing a receiving section 90 in the ultrasonic sensor M according to Embodiment 7.
  • the receiving section 90 according to Embodiment 7 differs from the receiving section 50 in Embodiment 3 only in that acoustic horns 91 are provided on the outer side of the protective film 14 .
  • Each of the acoustic horns 91 is formed so as to have a gradually increasing sectional area from a throat 91 a toward an opening 91 b.
  • the acoustic horn 91 is provided for each of the receiving elements 11 .
  • the throat 91 a of each of the acoustic horns 91 is located on the protective film 14 situated above (in front of) each of the receiving elements 11 . Specifically, the throat 91 a of each of the acoustic horns 91 is provided in front of each of the receiving elements 11 .
  • a horn wall member 91 c on an outer circumference of the throat 91 a is attached and fixed to an upper end of each of the separation members 51 .
  • the acoustic horns 91 A to 91 C are provided for three receiving elements 11 A to 11 C, respectively.
  • the throats 91 a of the respective acoustic horns 91 A to 91 C are provided on the protective films 14 A to 14 C situated above (in front of) the receiving elements 11 A to 11 C, respectively.
  • the structure of the ultrasonic sensor M in Embodiment 7 is obtained by replacing the receiving section 10 of the ultrasonic sensor M shown in FIG. 3 according to Embodiment 1 with the receiving section 90 .
  • Embodiment 7 the following functions and effects can be obtained in addition to the above-described functions and effects of Embodiment 3.
  • the directivity of a receiving direction of an ultrasonic wave can be provided for each of the receiving elements 11 .
  • the acoustic horns 91 A to 91 C have acute directivity on their horn axes a to ⁇ , respectively.
  • the acoustic horns 91 A to 91 C are formed to have the same size and shape as shown in FIG. 9A , so that the directivity of the receiving elements 11 A to 11 C can be set in the same direction if the horn axes a to y of the respective acoustic horns 91 A to 91 C are set in the same direction.
  • the directivity of each of the receiving elements 11 A to 11 C can be set in an arbitrary direction.
  • the transmission section 31 is made to have the same structure as that of the receiving section 90 and the acoustic horns 91 are provided on the outer side of the protective film 14 , the directivity of a transmission direction of an ultrasonic wave can be imparted to the transmission element.
  • the horn wall member 91 c on the outer circumference of the throat 91 a is attached and fixed to the upper end of each of the separation members 51 .
  • the horn wall member 91 c of the acoustic horn 91 is required to be formed of a material having enough strength to be hardly oscillated by an ultrasonic wave.
  • the material include various metals, various synthetic resins, and the like.
  • the transmission section 31 is made to have the same structure as that of the receiving section 90 and the acoustic horns 91 are provided on the outer side of the protective film 14 , the oscillation of the protective film 14 is not inhibited even if the acoustic horns 91 are provided because the horn wall member 91 c on the outer circumference of the throat 91 a is attached and fixed to the upper end of each of the separation members 51 . Accordingly, the transmission output of the transmission element can be prevented from being lowered.
  • FIG. 10 is a cross-sectional side view showing a receiving section 100 in the ultrasonic sensor M according to Embodiment 8.
  • the receiving section 100 according to Embodiment 8 differs from the receiving section 80 according to Embodiment 6 only in that the acoustic horns 91 are provided on the outer side of the protective film 14 as in the receiving section 90 according to Embodiment 7.
  • the horn wall member 91 c on the outer circumference of the throat 91 a in each of the acoustic horns 91 is attached and fixed to the protective film 14 .
  • the structure of the ultrasonic sensor M according to Embodiment 8 is obtained by replacing the receiving section 10 of the ultrasonic sensor M shown in FIG. 3 according to Embodiment 1 with the receiving section 100 .
  • Embodiment 8 the functions and effects described in [7-1] above in Embodiment 7 can be obtained in addition to the above-described functions and effects of Embodiment 6.
  • Embodiments 1 to 8 may be changed as follows. Even in such a case, the functions and effects equivalent to or superior to those of each of the embodiments described above can be obtained.
  • Each of the receiving sections 10 to 100 in Embodiments 1 to 8 includes the plurality of piezoelectric receiving elements 11 .
  • the piezoelectric receiving elements 11 may be replaced by capacitive receiving elements 111 so that the plurality of capacitive receiving elements 111 constitute each of the receiving sections 10 to 100 .
  • FIG. 11 is an enlarged cross-sectional side view showing one capacitive receiving element 111 .
  • An insulating layer 112 is formed on the surface of the substrate 12 .
  • a fixed electrode layer 113 is formed on a surface of the insulating layer 112 .
  • a movable electrode layer 114 is formed on a surface of the fixed electrode layer 113 through a clearance P.
  • An insulating layer 115 is formed around the electrode layers 113 and 114 . Surfaces of the insulating layer 115 and the movable electrode layer 114 (a device surface) are evened.
  • the bonding wires 28 and 29 are connected to the electrode layers 113 and 114 , respectively.
  • a capacitive element F is formed to have a structure in which the two electrodes 113 and 114 are provided so as to be opposed to each other through the clearance P.
  • the receiving element 111 includes the capacitive element F fabricated by employing the MEMS technique.
  • the surface of the movable electrode layer 114 forms the receiving surface 111 a of the receiving element 111 .
  • a conversion circuit (not shown) connected to the bonding wires 28 and 29 is used so as to convert a change in capacitance between the electrode layers 113 and 114 into an electric signal.
  • the movable electrode layer 114 can be prevented from being damaged so as to hardly break the receiving sections 10 to 100 even if the thin movable electrode layer 114 has a low mechanical strength as in the case where each of the receiving sections 10 to 100 is formed with the piezoelectric receiving elements 11 . As a result, the robust receiving sections 10 to 100 can be obtained.
  • the transmission section 31 in Embodiments 1 to 8 is formed with the piezoelectric transmission element having the same structure as that of the piezoelectric receiving element 11 .
  • the transmission section 31 may also be formed with a capacitive transmission element having the same structure as that of the capacitive receiving element 111 shown in FIG. 10 .
  • electrostatic attraction is generated between the electrode layers 113 and 114 in accordance with input signals applied to the electrode layers 113 and 114 .
  • the electrostatic attraction oscillates the movable electrode layer 114 to generate an ultrasonic wave.
  • the receiving face 11 a of the receiving element 111 acts as the transmission face of the transmission element for transmitting an ultrasonic wave.
  • the gap R surrounded by the substrate 12 and the housing member 13 is filled with air.
  • each of the layers 22 to 26 can be prevented from being excessively oscillated to be damaged.
  • a material for example, a liquid, a sol, a gel or the like
  • the ultrasonic sensor M according to Embodiments 1 to 8 is composed of a hybrid IC in which any one of the receiving sections 10 to 100 and the transmission section 31 corresponding to chip parts are attached and fixed onto the sensor substrate 32 made of an insulating plate material.
  • the ultrasonic sensor M may also be composed of a monolithic IC in which any one of the receiving sections 10 to 100 and the transmission section 31 are formed on the single substrate 12 . In this manner, the ultrasonic sensor M can be further reduced in size as well as in weight.
  • any one of or a plurality of the receiving elements 11 arranged on the substrate 12 may be made to act as a transmission element(s) of the transmission section 31 .
  • FIG. 12 is a schematic perspective view showing an ultrasonic sensor T.
  • the ultrasonic sensor T includes: a monolithic IC in which receiving section 10 , 40 , 50 , 80 , 90 or 100 and a transmission section U are formed on the single substrate 12 (not shown in FIG. 12 ; see FIGS. 13 to 17 ); the bonding wires 28 and 29 ; the sensor substrate 32 ; and electrode pads 33 .
  • the ultrasonic sensor T is further reduced in size as well as in weight as compared with the ultrasonic sensor M.
  • the transmission section U is composed of a single transmission element W.
  • the transmission element W has the same structure as that of each of the receiving elements 11 constituting the receiving section 10 , 40 , 50 , 80 , 90 , or 100 .
  • a tip of each of the bonding wires 28 and 29 led from the transmission element W is connected to each of the electrode pads 33 as in the case of the receiving element 11 .
  • the transmission element W having the same structure as that of the receiving element 11 transmits an ultrasonic wave from a transmission surface Wa (not shown) corresponding to the receiving surface 11 a of the receiving element 11 (not shown in FIG. 12 ; see FIGS. 13 to 17 ).
  • one element arranged at the corner is made to act as the transmission element W, whereas the other eight elements are made to act as the receiving elements 11 .
  • a plurality of arbitrary elements may be made to act as the transmission elements W among a plurality of elements having the same structure arranged on the substrate 12 .
  • FIG. 13 is a cross-sectional side view showing an example in which Embodiment 2 is applied to the ultrasonic sensor T, illustrating the receiving section 40 and the transmission section U of the ultrasonic sensor T.
  • FIG. 14 is a cross-sectional side view showing an example in which Embodiment 3 is applied to the ultrasonic sensor T, illustrating the receiving section 50 and the transmission section U of the ultrasonic sensor T.
  • FIG. 15 is a cross-sectional side view showing an example in which Embodiment 6 is applied to the ultrasonic sensor T, illustrating the receiving section 80 and the transmission section U of the ultrasonic sensor T.
  • FIGS. 16A and B are cross-sectional side views showing an example in which Embodiment 7 is applied to the ultrasonic sensor T, illustrating the receiving section 90 and the transmission section U of the ultrasonic sensor T.
  • FIG. 17 is a cross-sectional side view showing an example in which Embodiment 8 is applied to the ultrasonic sensor T, illustrating the receiving section 100 and the transmission section U of the ultrasonic sensor T.
  • FIG. 18 is a cross-sectional side view showing a receiving section 200 in an ultrasonic sensor N according to Embodiment 9.
  • the receiving section 200 includes a plurality of piezoelectric receiving elements 201 arranged in an array.
  • the example shown in FIG. 18 illustrates a cross-sectional side view of three receiving elements 201 .
  • the receiving elements 201 are formed on a single-crystalline silicon substrate (a single-crystalline silicon chip) 202 having an SOI structure.
  • the substrate 202 is provided on the sensor substrate 32 .
  • the substrate 202 is surrounded by a rectangular frame member 203 .
  • An outer circumference of the substrate 202 is attached and fixed to an inner wall of the frame member 203 by an appropriate method (for example, thermal welding, ultrasonic welding, bonding with an adhesive and the like) so as to air-seal a connection part between the outer circumference of the substrate 202 and the frame member 203 .
  • a lower end of the frame member 203 is attached and fixed to the sensor substrate 32 by the above-mentioned appropriate method so as to air-seal a connection part between the lower end of the frame member 203 and the sensor substrate 32 .
  • the frame member 203 and the sensor substrate 32 form a housing member 204 having a rectangular parallelepiped box shape with an upper open end.
  • the substrate 202 is housed within the housing member 204 having a rectangular parallelepiped box shape with an upper open end.
  • Each of the receiving elements 201 is arranged so that a receiving surface 201 a for receiving an ultrasonic wave is oriented toward an opening 204 a of the housing member 204 . Moreover, the receiving surfaces 201 a of the respective receiving elements 201 are arranged so as to be flush with each other.
  • the protective film 14 for closing the opening 204 a is attached over the opening 204 a of the housing member 204 .
  • the protective film 14 is provided in front of the receiving elements 201 .
  • An outer circumference of the protective film 14 is attached and fixed to an inner circumference of the frame member 203 (an inner circumference of the opening 204 a of the housing member 204 ) so as to air-seal a connection part between the outer circumference of the protective film 14 and the frame member 203 .
  • the gap S which is provided between the protective film 14 and the substrate 202 , is filled with a gas, a liquid, a sol, a gel or the like.
  • FIG. 19 is an enlarged cross-sectional side view showing one piezoelectric receiving element 201 .
  • a through hole 202 a penetrating through the substrate 202 is formed in the substrate 202 .
  • the insulating layer 21 , the silicon active layer 22 , and the insulating layer 23 are formed on the surface of the substrate 202 in this order.
  • the layers 22 and 23 are formed to close a lower end of the through hole 202 a.
  • the lower electrode layer 24 , the thin film layer 25 made of a ferroelectric (for example, PZT or the like), and the upper electrode layer 26 are formed in this order on the surface of the insulating layer 23 situated below (behind) the through hole 202 a.
  • a ferroelectric for example, PZT or the like
  • the sensor substrate 32 is a printed wiring board. Wiring layers 205 and 206 are formed on a surface of the sensor substrate 32 .
  • the lower electrode layer 24 and the wiring layer 205 are connected to each other through a bump 207
  • the upper electrode layer 26 and the wiring layer 206 are connected to each other through a bump 208 .
  • the bumps 207 and 208 may be formed by an appropriate method (plating, a stud method or the like) using various conductive materials (metals such as a solder, gold, copper and nickel, a conductive adhesive or the like).
  • a piezoelectric element (the piezoelectric sensor) E is formed to have a structure in which the thin film layer 25 made of a ferroelectric is sandwiched between the two thin electrode layers 24 and 26 .
  • the piezoelectric element E fabricated by employing the MEMS technique constitutes the receiving element 201 .
  • a surface of the silicon active layer 22 exposed through the through hole 202 a forms the receiving surface 201 a of the receiving element 201 .
  • the through hole 202 a is provided so that a diaphragm composed of the layers 22 and 26 is more likely to be oscillated.
  • FIG. 20 is a schematic perspective view showing the ultrasonic sensor N.
  • the ultrasonic sensor N is composed of a hybrid IC including the receiving section 200 , a transmission section 209 , and the sensor substrate 32 .
  • the receiving section 200 and the transmission section 209 corresponding to chip parts are attached and fixed to the surface of the sensor substrate 32 .
  • the receiving section 200 includes nine receiving elements 201 arranged 3 by 3.
  • the transmission section 209 has the same structure as that of any one of the receiving sections 10 to 100 and 200 .
  • the transmission section 209 includes one piezoelectric transmission element having the same structure as that of the receiving element 11 or 201 .
  • the thin film layer 25 is oscillated by a piezoelectric effect in accordance with an input signal applied to the thin film 25 made of a ferroelectric from the electrode layers 24 and 26 , thereby generating an ultrasonic wave.
  • the receiving surface 201 a of the receiving element 201 serves as a transmission surface for transmitting an ultrasonic wave.
  • the transmission element of the transmission section 209 converts an electric signal into an ultrasonic wave so as to transmit it.
  • the transmission section 209 transmits an ultrasonic wave in accordance with an input signal from the exterior.
  • a reflection sound generated by the ultrasonic wave reflected by an object to be detected is received by each of the receiving elements 201 of the receiving section 200 .
  • each of the receiving elements 201 of the receiving section 200 converts the received ultrasonic wave into an electric signal.
  • the ultrasonic wave transmitted from the transmission section 209 and the ultrasonic wave received by each of the receiving elements 201 of the receiving section 200 are compared with each other so as to obtain a sound pressure difference, a time difference, and a phase difference between them.
  • the position of an object to be detected, a distance between the ultrasonic sensor N and the object to be detected, a two-dimensional shape or a three-dimensional shape of the object to be detected and the like can be measured based on the thus obtained differences.
  • Embodiment 9 the following functions and effects can be obtained in addition to the same functions and effects as [1-1] to [1-4] described above in Embodiment 1.
  • the surface of the upper electrode layer 26 serves as the receiving surface 11 a.
  • each of the receiving elements 201 in Embodiment 9 the surface of the silicon active layer 22 exposed through the bottom face of the through hole 202 a serves as the receiving surface 202 a.
  • the receiving element 201 according to Embodiment 201 corresponds to a reversed version of the receiving element 11 according to Embodiment 1 for use.
  • the packaged receiving section 10 including the substrate 12 housed within the housing member 13 is attached and fixed onto the sensor substrate 32 . Then, the electrode layers 24 and 26 of each of the receiving elements 11 constituting the receiving section 10 and each of the electrode pads 33 are connected to each other through the bonding wires 28 and 29 , respectively.
  • the ultrasonic sensor according to Embodiment 1 has the following problems [A] to [E].
  • each of the bonding wires 28 and 29 is cut by the oscillation.
  • each of the bonding wires 28 and 29 is more likely to be cut because the oscillation of an engine or the oscillation propagating from a road surface is applied to the ultrasonic sensor M.
  • the transmission element of the transmission section 209 is made to have the same structure as that of the receiving element 11 , the fabrication cost for surface-mounting the transmission section 209 on the sensor substrate 32 is high.
  • the bonding wires 28 and 29 are provided above the receiving surface 11 a of each of the receiving elements 11 , the bonding wires 28 and 29 are likely to be cut by an ultrasonic wave received by each of the receiving elements 11 .
  • the transmission element of the transmission section 209 is made to have the same structure as that of the receiving element 11 , the bonding wires 28 and 29 become obstacles to inhibit an ultrasonic wave from being transmitted from the transmission surface of the transmission element. As a result, there is a possibility that the transmission output is lowered.
  • the bonding wires 28 and 29 are provided above the transmission surface of the transmission element, the bonding wires 28 and 29 are likely to be cut by an ultrasonic wave transmitted from the transmission element.
  • the transmission element of the transmission section 209 is made to have the same structure as that of the receiving element 11 , an inductance of a signal wiring in the transmission section 209 is increased by a length of each of the bonding wires 28 and 29 . Therefore, a transfer rate of an input signal to the transmission section 209 is lowered to lower an operation speed of the transmission section 209 .
  • the ultrasonic sensor M is disadvantageously increased in size.
  • each of the receiving elements 201 the unpackaged substrate 202 corresponding to a bare chip (die) is directly mounted facedown on the sensor substrate 32 .
  • the electrode layers 24 and 26 of each of the receiving elements 201 formed on the substrate 202 and the wiring layers 205 and 206 on the sensor substrate 32 are connected through the bumps 207 and 208 , respectively.
  • the receiving section 200 (the receiving elements 201 ) and the sensor substrate 32 are connected and fixed to each other through the bumps 207 and 208 , it can be ensured that the electrical connection between each of the receiving elements 201 and the substrate 32 is kept. As a result, the reliability of the ultrasonic sensor N can be enhanced with an extended lifetime.
  • the transmission element of the transmission section 209 is made to have the same structure as that of the receiving element 201 , it can be ensured that the electrical connection between the transmission element and the sensor substrate 32 is kept.
  • the transmission element of the transmission section 209 is made to have the same structure as that of the receiving element 201 , the fabrication cost for surface-mounting the transmission section 209 on the sensor substrate 32 can be lowered.
  • the bonding wire is no longer provided above the receiving surface 11 a of each of the receiving elements 11 , the bonding wire is never cut by the ultrasonic wave received by each of the receiving elements 11 .
  • the transmission element of the transmission section 209 is made to have the same structure as that of the receiving element 201 , the transmission of an ultrasonic wave from the transmission surface is not inhibited because the bonding wire is not provided above the transmission surface of the transmission element and therefore no obstacle is present in front of the transmission surface. As a result, the transmission output of the transmission element can be enhanced.
  • the bonding wire is not provided above the transmission surface of the transmission element, the bonding wire is never cut by the ultrasonic wave transmitted from the transmission element.
  • the transmission element of the transmission section 209 is made to have the same structure as that of the receiving element 201 , the inductance of the signal wiring of the transmission section 209 becomes smaller. Accordingly, the transfer rate of an input signal to the transmission section 209 becomes higher to increase the operation speed of the transmission section 209 .
  • the through hole 202 a can be made to act as the same acoustic horn as the acoustic horn 91 in Embodiment 7.
  • the bottom of the through hole 202 a corresponds to the throat 91 a of the acoustic horn 91 .
  • each of the receiving elements 201 can be provided with the directivity of a receiving direction of an ultrasonic wave as in the above-described [7-1] in Embodiment 7.
  • the transmission element of the transmission section 209 is made to have the same structure as that of the receiving element 201 , the transmission element can be provided with the directivity of a transmission direction of an ultrasonic wave.
  • the through hole 202 a can be made to act as an acoustic horn simply by appropriately shaping the through hole 202 a . Since it is no longer necessary to provide the acoustic horn 91 as an independent member as in Embodiment 7, the fabrication cost of the receiving section 200 and the transmission section 209 can be lowered as compared with the receiving section 90 and the transmission section 31 in Embodiment 7. At the same time, the receiving section 200 and the transmission section 209 can be reduced in size as well as in weight.
  • FIG. 21 is a cross-sectional side view showing a receiving section 220 in the ultrasonic sensor N according to Embodiment 10.
  • the receiving section 220 according to Embodiment 10 differs from the receiving section 200 according to Embodiment 9 only in that at least one (three in the illustrated example) vent hole 221 for bringing the gap R and the exterior of the housing member 204 into communication with each other is formed at a position of the sensor substrate 32 below each of the receiving elements 201 .
  • the structure of the ultrasonic sensor N according to Embodiment 10 is obtained by replacing the receiving section 200 in the ultrasonic sensor N shown in FIG. 20 according to Embodiment 20 with the receiving section 220 .
  • the receiving sensitivity of each of the receiving elements 201 can be prevented from being lowered because the oscillation of the layers 22 to 26 on the receiving surface 201 a of each of the receiving elements 201 is not inhibited.
  • the gap R surrounded by the substrate 202 and the housing member 204 the frame member 203 and the sensor substrate 32 forms a sealed space.
  • Air filling the sealed space acts as a spring so as to apply a damping force due to air on the back face side of the receiving surface 201 a of each of the receiving elements 201 .
  • the free oscillation of the layers 22 to 26 on the receiving surface 201 a is inhibited to lower the receiving sensitivity of each of the receiving elements 201 .
  • Embodiment 10 since air passes through the vent holes 221 , a damping force due to air is not applied to the back face side of the receiving surface 201 a of each of the receiving elements 201 . As a result, each of the layers 22 to 26 on the receiving surface 201 a is capable of freely oscillating.
  • the number, the position of arrangement, and the size and shape of the vent hole 221 can be determined by experimentally finding their optimal values by a cut-and-try method so as to obtain satisfactory functions and effects described above.
  • a filter material for example, a mesh filter or the like, which does not suppress the air permeability of the vent hole 221 , may be attached and fixed.
  • the transmission section 209 is made to have the same structure as that of the receiving section 220 and the vent hole 221 is provided at a position of the sensor substrate 32 below each of the transmission elements in the transmission section 209 , a damping force due to air is not applied to the back face side of the transmission surface of the transmission element because air passes through the vent holes 221 . Accordingly, the layers 22 to 26 on the transmission surface can freely oscillate so as not to suppress the oscillation, thereby increasing the transmission output of the transmission element.
  • FIG. 22 is a cross-sectional side view showing a receiving section 230 and a transmission section 231 in an ultrasonic sensor L according to Embodiment 11.
  • FIG. 23 is a schematic perspective view showing the ultrasonic sensor L.
  • the ultrasonic sensor L according to Embodiment 11 differs from the ultrasonic sensor N according to Embodiment 9 only in the following points.
  • the ultrasonic sensor L is composed of the monolithic IC including the receiving section 200 and the transmission section 231 formed on the single substrate 202 so as to be further reduced in size and weight as compared with the ultrasonic sensor N.
  • the transmission section 231 is composed of one transmission element 232 .
  • the transmission element 232 has the same structure as that of each of the receiving elements 201 constituting the receiving section 200 .
  • the transmission element 232 having the same structure as that of the receiving element 201 transmits an ultrasonic wave from a transmission surface 232 a corresponding to the receiving surface 201 a of the receiving element 201 .
  • one element arranged at the corner is made to act as the transmission element 232 , whereas the other eight elements are made to act as the receiving elements 201 .
  • an arbitrary number of elements can be made to act as the transmission elements 232 .
  • Partition members 233 are provided in the gap R surrounded by the substrate 202 and the housing member 204 (the frame member 203 and the sensor substrate 32 ).
  • a lower end of each of the partition members 233 is attached and fixed to an upper surface of the sensor substrate 32 by an appropriate method (for example, thermal welding, ultrasonic welding, bonding with an adhesive or the like) so as to air-seal a connection part between the lower end of each of the partition members 233 and the sensor substrate 32 .
  • An upper end of each of the partition members 233 is attached and fixed to a lower face of the insulating layer 23 on the substrate 202 by the above-mentioned appropriate method so as to air-seal a connection part between the upper end of each of the partition members 233 and the substrate 202 .
  • the partition members 233 partition the gap R for each of the elements 201 and 232 in an air-tight manner.
  • At least one (three in the illustrated example) vent hole 221 for bringing the gap R and the exterior of the housing member 204 into communication with each other is formed at a position of the sensor substrate 32 below each of the transmission elements 232 .
  • the vent hole 221 is not formed at a position of the sensor substrate 32 below each of the receiving elements 201 .
  • Embodiment 11 the following functions and effects can be obtained in addition to the above-described functions and effects of Embodiment 9.
  • the gap R surrounded by the substrate 202 and the housing member 204 (the frame member 203 and the sensor substrate 32 ) is formed as a sealed space
  • air filling the sealed space acts as a spring so as to apply a damping force due to air on the back face side of each of the faces (the receiving surface and the transmission surface) 201 a and 232 a of the respective elements 201 and 232 . Since the free oscillation of the layers 22 to 26 on each of the faces 201 a and 232 a is inhibited, a resonance value Q of the diaphragm composed of the layers 22 to 26 is reduced.
  • FIGS. 24A and 24B are characteristic views, each showing a resonance characteristic corresponding to the relation between the resonance value Q of the diaphragm and a frequency f.
  • the resonance value Q demonstrates a steep change with respect to a change in frequency f corresponding to the peak value Qa mainly at primary resonance frequencies fa and fb.
  • the resonance value Q demonstrates a gentle change with respect to a change in frequency f corresponding to the peak value Qb mainly at the primary resonance frequencies fa and fb.
  • the resonance value Q of the diaphragm and the transmission output of the transmission element 232 are positively correlated with each other; as the resonance value Q becomes larger, the transmission output becomes greater.
  • the piezoelectric element or the capacitive element fabricated by employing the MEMS technique is not suitable as a transmission element because it has a small transmission output of an ultrasonic wave.
  • the piezoelectric transmission element 232 fabricated by employing the MEMS technique is required to increase its transmission output as much as possible so as to have the resonance characteristic shown in FIG. 24A .
  • each of the transmission elements 232 can be provided with the resonance characteristic shown in FIG. 24A so as to increase the transmission output.
  • the resonance value Q of the diaphragm and the receiving sensitivity of the receiving element 201 are positively correlated with each other; as the resonance value Q becomes larger, the receiving sensitivity becomes greater.
  • each of the receiving elements 201 has a fluctuation in primary resonance frequency due to a fabrication process.
  • the receiving sensitivity at the frequencies fa and fb becomes extremely high.
  • the receiving sensitivity at a frequency fc between the frequencies fa and fb becomes extremely low.
  • the receiving sensitivity at the frequencies fa and fb is lower than that in FIG. 24A .
  • the receiving sensitivity at the frequency fc becomes higher than that in FIG. 24A .
  • the receiving sensitivity demonstrates a steep characteristic with respect to a change in frequency although the receiving sensitivity becomes high. Therefore, the receiving sensitivity at a frequency offset from the primary resonance frequency is suddenly lowered even if the offset is slight.
  • the receiving sensitivity demonstrates a gentle characteristic with respect to a change in frequency although the receiving sensitivity is lowered. Therefore, the receiving sensitivity at a frequency offset from the primary resonance frequency is not greatly lowered.
  • the piezoelectric element or the capacitive element fabricated by employing the MEMS technique has a high receiving sensitivity of an ultrasonic wave, it is suitable as the receiving element.
  • the piezoelectric receiving element 201 fabricated by employing the MEMS technique is required to have a high receiving sensitivity over a broad frequency range as much as possible rather than to have a high receiving sensitivity at the primary resonance frequency. Therefore, the piezoelectric receiving element 201 is required to have the resonance characteristic shown in FIG. 24B .
  • each of the receiving elements 201 is provided with the resonance characteristic shown in FIG. 24B to increase receiving sensitivity over a broad frequency range as much as possible.
  • the resonance value Q of the diaphragm composed of the layers 22 to 26 can be reduced as compared with the case where the gap R is filled with air.
  • the gap R is filled with a material for preventing the layers 22 to 26 from being excessively oscillated, the layers 22 and 26 can be prevented from being excessively oscillated to be broken.
  • FIG. 25 is a cross-sectional side view showing a receiving section 240 in the ultrasonic sensor N according to Embodiment 12.
  • the receiving section 240 according to Embodiment 12 differs from the receiving section 200 according to Embodiment 9 only in that separation members 241 are provided.
  • a lower end of each of the separation members 241 is attached and fixed to the substrate 202 between the receiving elements 201 by an appropriate method (for example, thermal welding, ultrasonic welding, bonding with an adhesive or the like) so as to air-seal a connection part of the lower end of each of the separation members 241 and the substrate 202 .
  • an appropriate method for example, thermal welding, ultrasonic welding, bonding with an adhesive or the like
  • each of the separation members 241 separates the gap S and the protective film 14 for each receiving element.
  • the lower ends of the separation members 241 are attached and fixed to the substrate 202 between the receiving elements 201 A and 202 B, and 202 B and 202 C, respectively.
  • the gaps SA to SC and the protective films 14 A to 14 C situated above (in front of) the receiving elements 201 A to 201 C are separated by the separation members 241 for the receiving elements 201 A to 201 C, respectively.
  • the structure of the ultrasonic sensor N according to Embodiment 12 is obtained by replacing the receiving section 200 of the ultrasonic sensor N shown in FIG. 20 according to Embodiment 9 with the receiving section 240 .
  • Embodiment 12 the following functions and effects can be obtained in addition to the above-described functions and effects of Embodiment 9.
  • the gaps SA to SC and the protective films 14 A to 14 C situated above (in front of) the receiving elements 201 A to 201 C are separated by the separation members 241 for each of the receiving elements 201 A to 201 C, respectively. Therefore, the oscillation of the single protective film 14 A obtained by the separation propagates only to the receiving element 201 A through the gap SA situated below the protective film 14 A but not to the other receiving elements 201 B and 201 C.
  • an ultrasonic wave can be received by each of the receiving elements 201 A to 201 C in a separate manner. Accordingly, a crosstalk characteristic of each of the receiving elements 201 A to 201 C can be prevented from being degraded.
  • a plurality of the adjacent receiving elements 201 may be grouped into one.
  • the separation member 241 may be provided for each group so as to separate the group from the other groups.
  • the separation members 241 have to surely block the oscillation of the protective film 14 A and the gap SA vertically arranged to be grouped into one so that the oscillation does not propagate to the members of the other adjacent groups (the protective films 14 B and 14 C and the gaps SB and SC).
  • a material having a high oscillation blocking property is required to be used for the separation members 241 .
  • the material include rubbers.
  • FIG. 26 is a cross-sectional side view showing the receiving section 240 in the ultrasonic sensor N according to a first variation of Embodiment 12.
  • the first variation shown in FIG. 26 differs from Embodiment 12 shown in FIG. 25 only in that the vent holes 221 for bringing the gap R and the exterior of the housing member 204 into communication with each other are formed at a position of the sensor substrate 32 below each of the receiving elements 201 .
  • Embodiment 12 corresponds to the combination of Embodiments 12 and 10. Accordingly, the functions and effects of Embodiment 10 can be obtained in addition to the functions and effects of Embodiment 12.
  • FIG. 27 is a cross-sectional side view showing the receiving section 240 and the transmission section 231 in the ultrasonic sensor L according to a second variation of Embodiment 12.
  • the second variation shown in FIG. 27 differs from Embodiment 12 shown in FIG. 25 only in that the same points as described in [a] to [c] of Embodiment 12.
  • Embodiment 12 corresponds to the combination of Embodiments 12 and 11. Therefore, the above-described functions and effects of Embodiment 11 can be obtained in addition to the functions and effects of Embodiment 12.
  • FIG. 28 is a cross-sectional side view showing a receiving section 250 in the ultrasonic sensor N according to Embodiment 13.
  • the receiving section 250 of Embodiment 13 differs from the receiving section 200 of Embodiment 9 only in that separation members 251 are provided.
  • a lower end of each of the separation members 251 is attached and fixed to an upper surface of the sensor substrate 32 by an appropriate method (for example, thermal welding, ultrasonic welding, bonding with an adhesive and the like) so as to air-seal a connection part between the lower end of each of the separation members 251 and the sensor substrate 32 .
  • an appropriate method for example, thermal welding, ultrasonic welding, bonding with an adhesive and the like
  • each of the separation members 251 separates the space S and the protective film 14 for each of the receiving elements 201 .
  • the lower ends of the separation members 251 are attached and fixed to the upper surface of the sensor substrate 32 between the receiving elements 201 A and 201 B, and 201 B and 201 C, respectively, whereby the separation members 251 separate the receiving elements 201 A to 201 C from each other.
  • the gaps SA to SC and the protective films 14 A to 14 C respectively situated above (in front of) the receiving elements 201 A to 201 C are separated by the separation members 251 for each of the receiving elements 201 A to 201 C, respectively.
  • the receiving section 200 according to Embodiment 9 is composed of a monolithic IC including the receiving elements 201 of the receiving section 230 formed on the single substrate 202 .
  • the receiving section 250 of Embodiment 13 is composed of a hybrid IC including the receiving elements 201 corresponding to chip parts attached and fixed on the sensor substrate 32 .
  • the structure of the ultrasonic sensor N according to Embodiment 13 is obtained by replacing the receiving section 200 of the ultrasonic sensor N shown in FIG. 20 according to Embodiment 9 with the receiving section 250 .
  • Embodiment 13 the following functions and effects can be obtained in addition to the functions and effects of Embodiment 9.
  • the receiving elements 201 A to 201 C, and the gaps SA to SC and the protective films 14 A to 14 C situated above (in front of) the receiving elements 201 A to 201 C are separated by the separation members 251 for each of the receiving elements 201 . Therefore, the oscillation of one protective film 14 A obtained by the separation propagates only to the receiving element 201 A through the gap SA situated below the protective film 14 A but not to the other receiving elements 201 B and 201 C at all.
  • an ultrasonic wave can be received by each of the receiving elements 201 A to 201 C in a completely separate manner, so that a crosstalk characteristic of each of the receiving elements 201 A to 201 C can be prevented from being degraded.
  • a plurality of adjacent receiving elements 201 may be grouped into one.
  • the separation member 251 may be provided for each of the groups so as to separate the group from the other groups.
  • the separation members 251 have to surely block the oscillation of the protective film 14 A, the gap SA and the receiving element 201 A, which are vertically arranged so as to be grouped into one, so that the oscillation does not propagate to the members of the other adjacent groups (the protective films 14 B and 14 C, the gaps SB and SC, and the receiving elements 201 B and 201 C).
  • the separation member 251 a material having a high oscillation blocking property is required to be used for the separation member 251 .
  • the material include rubbers.
  • FIG. 29 is a cross-sectional side view showing the receiving section 250 in the ultrasonic sensor N according to a first variation of Embodiment 13.
  • the first variation shown in FIG. 29 differs from Embodiment 13 shown in FIG. 28 only in that the vent holes 221 for bringing the gap R and the exterior of the housing member 204 into communication with each other are formed at a position of the sensor substrate 32 below each of the receiving elements 201 .
  • the first variation of Embodiment 13 corresponds to the combination of Embodiments 13 and 10. Therefore, in addition to the functions and effects of Embodiment 13, the functions and effects of Embodiment 10 can be obtained.
  • FIG. 30 is a cross-sectional side view showing the receiving section 250 and the transmission section 231 in the ultrasonic sensor L according to a second variation of Embodiment 13.
  • the second variation shown in FIG. 30 differs from Embodiment 13 shown in FIG. 28 only in that one of the receiving elements 201 (the receiving element 201 A) constituting the receiving section 250 is made to act as the transmission element 232 constituting the transmission section 231 as in the ultrasonic sensor L and the same points as the above-described [b] and [c] in Embodiment 11.
  • the separation members 251 function as the partition members 233 of Embodiment 11.
  • Embodiment 13 corresponds to the combination of Embodiments 13 and 11. Therefore, in addition to the functions and effects of Embodiment 13, the functions and effects of Embodiment 11 can be obtained.
  • FIG. 31 is a cross-sectional side view showing a receiving section 260 in the ultrasonic sensor N in Embodiment 14.
  • the receiving section 260 of Embodiment 14 differs from the receiving section 200 of Embodiment 9 only in that a column-like transfer member 261 for connecting the receiving surface 201 a of each of the receiving elements 201 and the protective film 14 with each other independently for each of the receiving elements 201 is provided in the gap S.
  • the structure of the ultrasonic sensor N according to Embodiment 14 is obtained by replacing the receiving section 200 of the ultrasonic sensor N shown in FIG. 20 according to Embodiment 9 with the receiving section 260 .
  • Embodiment 14 the following functions and effects can be obtained in addition to the functions and effects described above in [9-1] of Embodiment 9.
  • the oscillation of the protective film 14 propagates to each of the receiving elements 201 through each of the transfer members 261 .
  • the transfer member 261 is provided for each of the receiving elements 201 , the oscillation of arbitrary one of the transfer members 261 does not propagate to the other transfer members 261 . Therefore, an ultrasonic wave can be received by each of the receiving elements 201 in a separate manner, thereby preventing a crosstalk characteristic of each of the receiving elements 201 from being degraded.
  • the propagation of oscillation of the protective film 14 to each of the transfer members 261 can be ensured by bringing an acoustic impedance of each of the transfer members 261 close to that of the protective film 14 .
  • the receiving sensitivity of each of the receiving elements 201 can be enhanced.
  • each of the transfer members 261 to the silicon active layer 22 can be ensured by bringing an acoustic impedance of each of the transfer members 261 close to that of the silicon active layer 22 of each of the receiving elements 201 .
  • the receiving sensitivity of each of the receiving elements 201 can be enhanced.
  • the transfer members 261 of the same material as that of the protective film 14 or the silicon active layer 22 .
  • the transmission section 209 is made to have the same structure as that of the receiving section 260 and the transfer member 261 for bringing the transmission surface of the transmission element and the protective film 14 into communication with each other is provided, the propagation of oscillation of the transfer member 261 to the protective film 14 can be ensured by bringing the acoustic impedance of the transfer member 261 close to that of the protective film 14 . As a result, the transmission output of the transmission element can be enhanced.
  • the propagation of oscillation of the silicon active layer 22 of the transmission element to the transfer member 261 can be ensured by bringing the acoustic impedance of the transfer member 261 close to that of the silicon active film 22 .
  • the transmission output of the transmission element can be enhanced.
  • Embodiment 14 the same functions and effects as those in [6-1] of Embodiment 6 described above can be obtained.
  • Embodiment 14 it is the most desirable that the gap S be in a vacuum state.
  • the gap S is filled with a filler in Embodiment 14, a gas with a small acoustic impedance or a material having a high oscillation absorbance (for example, a highly viscous gel or the like) is used as the filler.
  • a gas with a small acoustic impedance or a material having a high oscillation absorbance for example, a highly viscous gel or the like
  • Embodiment 14 the same functions and effects as those in [6-2] in Embodiment 6 above can be obtained.
  • FIG. 32 is a cross-sectional side view showing a receiving section 260 in the ultrasonic sensor N according to a first variation of Embodiment 14.
  • the first variation shown in FIG. 32 differs from Embodiment 14 shown in FIG. 31 only in that the vent holes 221 for bringing the gap R and the exterior of the housing member 204 into communication with each other are formed at a position of the sensor substrate 32 below each of the receiving elements 201 .
  • Embodiment 14 corresponds to the combination of Embodiments 14 and 10. Therefore, the functions and effects of Embodiment 10 described above can be obtained in addition to the above-described functions and effects of Embodiment 14.
  • FIG. 33 is a cross-sectional side view showing the receiving section 260 and the transmission section 231 in the ultrasonic sensor N according to a second variation of Embodiment 14.
  • the second variation shown in FIG. 33 differs from Embodiment 14 shown in FIG. 31 only in the same points as [a] to [c] of Embodiment 11 described above.
  • Embodiment 14 corresponds to the combination of Embodiments 14 and 11. Therefore, the functions and effects of Embodiment 11 described above can be obtained in addition to the above-described functions and effects of Embodiment 14.
  • Each of the receiving sections 200 to 260 according to Embodiments 9 to 14 is constituted by the plurality of piezoelectric receiving elements 201 .
  • each of the piezoelectric receiving elements 201 may be replaced by a capacitive receiving element 271 so that each of the receiving sections 200 to 260 is constituted by the plurality of capacitive receiving elements 271 .
  • FIG. 34 is an enlarged cross-sectional side view showing one capacitive receiving element 271 .
  • the through hole 202 a penetrating through the substrate 202 is formed in the substrate 202 .
  • an insulating layer 272 is formed on the surface of the substrate 202 so as to close the lower end of the through hole 202 a.
  • a fixed electrode layer 273 is formed on a surface of the insulating layer 272 situated below (behind) the through hole 202 a .
  • a movable electrode layer 274 is formed on a surface of the fixed electrode layer 273 through a clearance P. Spacers 275 are provided between the electrode layers 273 and 274 in their circumferential area. The electrode layers 273 and 274 are connected and fixed to each other through the spacers 275 .
  • the wiring layers 205 and 206 are formed on the surface of the sensor substrate 32 .
  • the fixed electrode layer 273 and the wiring layer 205 are connected with each other through the bump 207 , whereas the movable electrode layer 204 and the wiring layer 206 are connected with each other through the bump 208 .
  • the receiving element 271 includes the capacitive element F fabricated by employing the MEMS technique.
  • the surface of the insulating layer 272 exposed through the bottom of the through hole 202 a forms a receiving surface 271 a of the receiving element 271 .
  • a distance between the electrode layers 273 and 274 changes so as to change a capacitance.
  • a converting circuit (not shown) connected to the wiring layers 205 and 206 is used to convert a change in capacitance between the electrode layers 273 and 274 into an electric signal.
  • the movable electrode layer 274 is prevented from being damaged so as to be unlikely to break each of the receiving sections 200 to 260 even if the thin movable electrode layer 274 has a low mechanical strength as in the case where each of the receiving sections 200 to 260 includes the piezoelectric receiving elements 201 .
  • the robust receiving sections 200 to 260 can be obtained.
  • Each of the transmission sections 209 and 231 according to Embodiments 9 to 14 includes the piezoelectric transmission elements having the same structure as that of the piezoelectric receiving element 201 .
  • each of the transmission sections 209 and 231 may be composed of a capacitive transmission element having the same structure as that of the capacitive receiving element 271 shown in FIG. 34 .
  • electrostatic attraction is generated between the electrode layers 273 and 274 in accordance with an input signal applied to each of the electrode layers 273 and 274 .
  • the electrostatic attraction causes the oscillation of the movable electrode layer 274 to generate an ultrasonic wave.
  • the receiving surface 271 a of the receiving element 271 acts as a transmission surface of the transmission element for transmitting an ultrasonic wave.
  • the protective film 14 may be omitted while the transfer member 261 may be replaced by the same protective member as the protective member 41 in Embodiment 2.
  • the ultrasonic sensor N according to Embodiments 9, 10, 12 and 14 and the first variations of Embodiments 12 and 14 is composed of a hybrid IC in which the receiving section 200 , 220 , 240 or 260 and the transmission section 209 corresponding to chip parts are attached and fixed onto the sensor substrate 32 made of an insulating plate material.
  • the ultrasonic sensor N according to Embodiments 9, 10, 12 and 14 and the first variations of Embodiments 12 and 14 may be composed of a monolithic IC in which the receiving section 200 , 220 , 240 or 260 and the transmission section 231 are formed on the single substrate 202 as in the case of the ultrasonic sensor L shown in FIG. 23 .
  • At least arbitrary one of the receiving elements 201 constituting the receiving section 250 may be made to act as the transmission element 232 constituting the transmission section 231 in the ultrasonic sensor N according to Embodiment 13 and the first variation of Embodiment 13.
  • FIG. 35 is a cross-sectional side view showing an example in which Embodiment 9 is applied to the ultrasonic sensor L, illustrating the receiving section 200 and the transmission section 231 of the ultrasonic sensor L.
  • Embodiment 9 differs from Embodiment 9 only in the above-described point [a] in Embodiment 11.
  • FIG. 36 is a cross-sectional side view showing an example in which Embodiment 12 is applied to the ultrasonic sensor L, illustrating the receiving section 240 and the transmission section 231 of the ultrasonic sensor L.
  • Embodiment 12 differs from Embodiment 12 only in the above-described point [a] in Embodiment 11.
  • FIG. 37 is a cross-sectional side view showing an example in which Embodiment 13 is applied to the ultrasonic sensor L, illustrating the receiving section 250 and the transmission section 231 of the ultrasonic sensor L.
  • This example differs from Embodiment 13 only in that one (the receiving element 201 A) of the receiving elements 201 constituting the receiving section 250 is made to act as the transmission element 232 constituting the transmission section 231 .
  • FIG. 38 is a cross-sectional side view showing an example in which Embodiment 14 is applied to the ultrasonic sensor L, illustrating the receiving section 260 and the transmission section 231 of the ultrasonic sensor L.
  • Embodiment 14 differs from Embodiment 14 only in the above-described point [a] in Embodiment 11.
  • the present invention is not limited to the above-described embodiments, but can also be embodied as follows. In such a case, the functions and effects equivalent to or higher than those of each of the embodiments described above can be obtained.
  • an existing small ultrasonic sensor may be used.
  • a piezoelectric element or a capacitive element fabricated by employing the MEMS technique is suitable for a receiving element for its high receiving sensitivity of an ultrasonic wave, it is not suitable for a transmission element for its small transmission output of an ultrasonic wave.
  • optimal one of the transmission sections 31 and 209 and 231 may be selected for use in accordance with the field of use of the ultrasonic sensor M.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • General Engineering & Computer Science (AREA)
  • Transducers For Ultrasonic Waves (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
US11/208,724 2004-08-25 2005-08-23 Ultrasonic sensor Abandoned US20060043843A1 (en)

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Cited By (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070157731A1 (en) * 2006-01-11 2007-07-12 Denso Corporation Ultrasonic sensor
US20070158502A1 (en) * 2002-11-04 2007-07-12 Bonutti Peter M Ultrasonic communication and drag modification
US20070251324A1 (en) * 2006-04-26 2007-11-01 Denso Corporation Ultrasonic sensor and manufacture method of the same
US20080088206A1 (en) * 2006-10-13 2008-04-17 Denso Corporation Resin substrate and ultrasonic sensor using the same
US20080165620A1 (en) * 2005-07-20 2008-07-10 Denso Corporation Obstacle sensor having supersonic sensor
US20090071255A1 (en) * 2007-06-12 2009-03-19 Denso Corporation Ultrasonic sensor and self diagnostic method of the same
US20090085439A1 (en) * 2007-09-28 2009-04-02 Denso Corporation Ultrasonic sensor
US7821872B2 (en) 2007-08-31 2010-10-26 Denso Corporation Method for ultrasonic wave transmission and apparatus for ultrasonic wave transmission
US20100275675A1 (en) * 2007-12-05 2010-11-04 Heikki Seppa Device for measuring pressure, variation in acoustic pressure, a magnetic field, acceleration, vibration, or the composition of a gas
US20110227449A1 (en) * 2010-03-19 2011-09-22 Seiko Epson Corporation Ultrasonic sensor
US20130098157A1 (en) * 2011-10-21 2013-04-25 Riso Kagaku Corporation Ultrasonic sensor
US20130208572A1 (en) * 2010-07-30 2013-08-15 Koninklijke Philips Electronics N.V. Thin film ultrasound transducer
CN103770701A (zh) * 2013-05-15 2014-05-07 宁波保税区攀峒信息科技有限公司 一种特定物体近距离视觉盲区人体探测方法及装置
US20140276080A1 (en) * 2010-04-27 2014-09-18 Seiko Epson Corporation Ultrasonic sensor and electronic device
US20150258573A1 (en) * 2014-03-10 2015-09-17 Seiko Epson Corporation Ultrasonic sensor
US20160013394A1 (en) * 2014-07-11 2016-01-14 Microtech Medical Technologies Ltd. Multi-cell transducer
US20160027424A1 (en) * 2013-04-24 2016-01-28 Murata Manufacturing Co., Ltd. Ultrasonic wave generation apparatus
US20160036412A1 (en) * 2014-07-31 2016-02-04 Seiko Epson Corporation Ultrasonic device and probe as well as electronic apparatus and ultrasonic imaging apparatus
US20160139250A1 (en) * 2013-06-20 2016-05-19 Robert Bosch Gmbh Surroundings-sensing device having a modular ultrasonic transducer, and motor vehicle having such a surroundings-sensing device
US9348027B2 (en) 2011-06-13 2016-05-24 Denso Corporation Ultrasonic sensor device
US9554775B2 (en) 2012-03-30 2017-01-31 Seiko Epson Corporation Ultrasonic transducer element chip, probe, electronic instrument, and ultrasonic diagnostic device
US9818929B2 (en) 2013-11-20 2017-11-14 Seiko Epson Corporation Ultrasonic device, method for manufacturing the same, electronic device and ultrasonic imaging device
CN109150127A (zh) * 2018-07-27 2019-01-04 开元通信技术（厦门）有限公司 薄膜体声波谐振器及其制作方法、滤波器
CN111208498A (zh) * 2018-11-22 2020-05-29 精工爱普生株式会社 超声波元件及超声波装置
US20200186937A1 (en) * 2016-12-08 2020-06-11 Bae Systems Plc Electroacoustic transducer array
US20210009046A1 (en) * 2019-07-10 2021-01-14 Denso Corporation Ultrasonic sensor
US10929633B2 (en) 2016-09-18 2021-02-23 Boe Technology Group Co., Ltd. Fingerprint identification device, touch display panel, and method for driving fingerprint identification device
CN112805843A (zh) * 2018-08-01 2021-05-14 艾科索成像公司 用于集成具有混合触点的超声换能器的系统和方法
CN112887881A (zh) * 2019-11-29 2021-06-01 精工爱普生株式会社 超声波设备
US11179748B2 (en) 2017-05-09 2021-11-23 Seiko Epson Corporation Mounting structure, ultrasonic device, ultrasonic probe, ultrasonic apparatus, and electronic apparatus
US11181627B2 (en) * 2018-02-05 2021-11-23 Denso Corporation Ultrasonic sensor
GB2564914B (en) * 2017-07-19 2022-08-31 Bae Systems Plc Electroacoustic transducer array
US11445304B2 (en) 2019-04-05 2022-09-13 Denso Corporation Ultrasonic sensor
US11666239B2 (en) 2017-03-14 2023-06-06 University Of Connecticut Biodegradable pressure sensor
US11678989B2 (en) * 2019-03-01 2023-06-20 University Of Connecticut Biodegradable piezoelectric nanofiber scaffold for bone or tissue regeneration
US11745001B2 (en) 2020-03-10 2023-09-05 University Of Connecticut Therapeutic bandage
US11826495B2 (en) 2019-03-01 2023-11-28 University Of Connecticut Biodegradable piezoelectric ultrasonic transducer system
US11910720B2 (en) 2019-12-26 2024-02-20 Seiko Epson Corporation Piezoelectric device and MEMS device
US11917922B2 (en) * 2016-04-27 2024-02-27 Seiko Epson Corporation Mounting structure, ultrasonic device, ultrasonic probe, ultrasonic apparatus, and electronic apparatus

Families Citing this family (57)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110022509A1 (en) * 2005-11-13 2011-01-27 Rosenthal Collins Group, L.L.C. Method and system for electronic trading via a yield curve on plural network devices
JP4787648B2 (ja) * 2006-03-29 2011-10-05 パナソニック株式会社 コンデンサマイクロホンの製造方法およびコンデンサマイクロホン
AU2007240129B2 (en) * 2006-04-19 2012-07-26 Commonwealth Scientific And Industrial Research Organisation Ultrasonic transducer systems
JP2007306043A (ja) * 2006-05-08 2007-11-22 Denso Corp 超音波センサ
JP4702255B2 (ja) * 2006-10-13 2011-06-15 株式会社デンソー 超音波センサ
US7863856B2 (en) * 2008-01-11 2011-01-04 Modu Ltd. Bi-directional battery charging for coupled electronic devices
JP4958631B2 (ja) * 2007-05-14 2012-06-20 株式会社日立製作所 超音波送受信デバイス及びそれを用いた超音波探触子
DE102008054533B8 (de) 2007-12-26 2013-02-14 Denso Corporation Ultraschallsensor
GB0916480D0 (en) * 2009-09-21 2009-10-28 Univ Dundee Wire bond free connection of high frequency piezoelectric ultrasound transducer arrays
JP5671876B2 (ja) * 2009-11-16 2015-02-18 セイコーエプソン株式会社 超音波トランスデューサー、超音波センサー、超音波トランスデューサーの製造方法、および超音波センサーの製造方法
JP5600431B2 (ja) * 2009-12-28 2014-10-01 日本碍子株式会社 障害物の超音波検知デバイス
JP5517642B2 (ja) * 2010-01-26 2014-06-11 キヤノン株式会社 音響波探触子
FR2965249B1 (fr) * 2010-09-28 2013-03-15 Eurocopter France Systeme de degivrage ameliore pour voilure fixe ou tournante d'un aeronef
FR2966813A1 (fr) * 2010-10-29 2012-05-04 Thales Sa Microsysteme electromecanique (mems).
DE102011079646A1 (de) * 2011-07-22 2013-02-07 Robert Bosch Gmbh Ultraschallsensorvorrichtung zum Erfassen und/oder Senden von Ultraschall
DE102011084537B4 (de) 2011-10-14 2017-05-04 Robert Bosch Gmbh Ultraschallsensorarray
JP5885296B2 (ja) * 2012-02-15 2016-03-15 日本電波工業株式会社 超音波探触子
DE102012204638A1 (de) * 2012-03-22 2013-09-26 Robert Bosch Gmbh Ultraschallsensor und Verfahren zur Messung eines Objektabstands
JP6019671B2 (ja) * 2012-03-30 2016-11-02 セイコーエプソン株式会社 超音波プローブ並びに電子機器および超音波診断装置
JP6065421B2 (ja) * 2012-06-15 2017-01-25 セイコーエプソン株式会社 超音波プローブおよび超音波検査装置
JP6135088B2 (ja) * 2012-10-12 2017-05-31 セイコーエプソン株式会社 超音波トランスデューサーデバイス、プローブヘッド、超音波プローブ、電子機器及び超音波診断装置
US20140265732A1 (en) * 2013-03-15 2014-09-18 Piezotech, Llc Pressure-compensated transducer assembly
JP6442821B2 (ja) * 2013-09-30 2018-12-26 セイコーエプソン株式会社 超音波デバイス及び電子機器
CA2929723C (en) 2013-12-12 2020-09-15 Qualcomm Incorporated Micromechanical ultrasonic transducers and display
US9772314B2 (en) * 2013-12-18 2017-09-26 Seiko Epson Corporation Ultrasonic sensor and measuring method using the same, and method of manufacturing ultrasonic sensor
JP6458934B2 (ja) * 2013-12-18 2019-01-30 セイコーエプソン株式会社 超音波センサー
CA2950919A1 (en) * 2014-07-08 2016-01-14 Qualcomm Incorporated Piezoelectric ultrasonic transducer and process
JP6587051B2 (ja) * 2015-03-24 2019-10-09 セイコーエプソン株式会社 超音波センサー及びその製造方法
US9506790B2 (en) * 2015-03-24 2016-11-29 Daniel Measurement And Control, Inc. Transducer mini-horn array for ultrasonic flow meter
DE102015209238A1 (de) * 2015-05-20 2016-11-24 Robert Bosch Gmbh Akustischer Sensor zum Senden und Empfangen akustischer Signale
DE102015213989A1 (de) 2015-07-24 2017-01-26 Robert Bosch Gmbh Akustischer Sensor zum Aussenden und/oder Empfangen akustischer Signale
CN107683611B (zh) * 2015-08-31 2019-10-18 丰达电机株式会社 电声转换器、具有电声转换器的组装体以及具有该组装体的电声转换装置
CN208257660U (zh) * 2015-09-10 2018-12-18 株式会社村田制作所 压电振动器件、压电变压器模块、压电振子安装用柔性基板和压电变压器
JP6728630B2 (ja) * 2015-10-29 2020-07-22 セイコーエプソン株式会社 圧電素子、圧電モジュール、電子機器、及び圧電素子の製造方法
DE102015223502A1 (de) 2015-11-27 2017-06-01 Robert Bosch Gmbh Akustisch sensitives Gehäuse und Verfahren zum Empfangen von akustischen Signalen
JP6801328B2 (ja) 2016-04-27 2020-12-16 セイコーエプソン株式会社 実装構造体、超音波デバイス、超音波探触子、超音波装置、及び電子機器
CN105835774A (zh) * 2016-06-08 2016-08-10 成都谷辘信息技术有限公司 一种基于gps的车辆防撞预警系统
TWI592657B (zh) * 2016-08-08 2017-07-21 國立臺灣科技大學 能產生不同振動頻率的壓電材料構件及探頭結構
CN107797114A (zh) * 2016-09-02 2018-03-13 法雷奥汽车内部控制（深圳）有限公司 一种用于机动车的超声波传感器
JP6265578B1 (ja) * 2016-09-07 2018-01-24 株式会社アルバック デバイス及びデバイスの製造方法並びにアレイ型の超音波プローブの製造方法
WO2018047585A1 (ja) * 2016-09-07 2018-03-15 株式会社アルバック デバイス及びデバイスの製造方法並びにアレイ型の超音波プローブの製造方法
EP3339854B1 (de) * 2016-12-21 2021-02-03 Honeywell International Inc. Explosionsgeschützter piezoelektrischer ultraschalldetektor
JP6939219B2 (ja) * 2017-08-03 2021-09-22 セイコーエプソン株式会社 超音波装置
JP7192510B2 (ja) * 2018-02-05 2022-12-20 株式会社デンソー 超音波センサ
KR102415468B1 (ko) 2018-02-14 2022-07-01 삼성전자주식회사 디스플레이의 아래에 배치된 생체 센서와 디스플레이 사이의 공간을 채우기 위한 충진재를 포함하는 전자 장치
US10966683B2 (en) * 2018-03-22 2021-04-06 Exo Imaging Inc. Integrated ultrasonic transducers
US10748831B2 (en) * 2018-05-30 2020-08-18 Taiwan Semiconductor Manufacturing Co., Ltd. Semiconductor packages having thermal through vias (TTV)
DE102018210486A1 (de) * 2018-06-27 2020-01-02 Zf Friedrichshafen Ag Vorrichtung und Verfahren zum Erfassen von Umgebungsgeräuschen
US11517938B2 (en) * 2018-08-21 2022-12-06 Invensense, Inc. Reflection minimization for sensor
TWI675498B (zh) * 2018-12-07 2019-10-21 茂丞科技股份有限公司 晶圓級超聲波晶片模組及其製造方法
AU2020245521B2 (en) 2019-03-25 2022-02-17 Exo Imaging, Inc. Handheld ultrasound imager
JP7088099B2 (ja) * 2019-03-25 2022-06-21 株式会社デンソー 超音波センサ
JP7192640B2 (ja) * 2019-04-23 2022-12-20 株式会社Soken 超音波センサ
TWI729605B (zh) * 2019-12-04 2021-06-01 茂丞科技股份有限公司 晶圓級超聲波裝置及其製造方法
JP7439728B2 (ja) * 2020-01-08 2024-02-28 株式会社デンソー 超音波センサ
JP7439689B2 (ja) * 2020-01-14 2024-02-28 株式会社デンソー 超音波センサ
DE102021129855A1 (de) 2021-11-16 2023-05-17 Infineon Technologies Ag Ultraschallberührungssensor

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4642508A (en) * 1984-03-09 1987-02-10 Kabushiki Kaisha Toshiba Piezoelectric resonating device
US6341408B2 (en) * 1996-11-26 2002-01-29 Thomson-Csf Method of manufacturing a multiple-element acoustic probe comprising a common ground electrode
US6396199B1 (en) * 1999-07-02 2002-05-28 Prosonic Co., Ltd. Ultrasonic linear or curvilinear transducer and connection technique therefore
US6685657B2 (en) * 1998-11-20 2004-02-03 Joie P. Jones Methods for selectively dissolving and removing materials using ultra-high frequency ultrasound
US6891314B2 (en) * 2001-08-22 2005-05-10 Fuji Xerox Co., Ltd Lattice array-structured piezoelectric actuator and method for producing the same

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2452068A (en) * 1943-01-23 1948-10-26 Submarine Signal Co Sound pickup device
US3130275A (en) * 1962-10-15 1964-04-21 Electro Voice Microphone
JPS5935865U (ja) * 1982-08-31 1984-03-06 三菱電機株式会社 超音波探触子装置
DE3721209C2 (de) * 1987-06-26 1997-04-30 Grieshaber Vega Kg Schall-/Ultraschallmeßgerät
DE4139024C1 (de) * 1991-11-27 1993-04-15 Siemens Ag, 8000 Muenchen, De
US5297553A (en) * 1992-09-23 1994-03-29 Acuson Corporation Ultrasound transducer with improved rigid backing
DE4320549C1 (de) * 1993-06-21 1994-07-14 Siemens Ag Ultraschallwandler
US5459368A (en) * 1993-08-06 1995-10-17 Matsushita Electric Industrial Co., Ltd. Surface acoustic wave device mounted module
KR19980026603A (ko) * 1996-10-10 1998-07-15 박병재 주차시 머플러 밀림 방지 장치
KR200188749Y1 (ko) * 1996-12-24 2000-09-01 이구택 되돌이탄호퍼내 되돌이탄 레벨검출장치
US6250162B1 (en) * 1998-04-24 2001-06-26 Murata Manufacturing Co., Ltd. Ultrasonic sensor
JP4240426B2 (ja) * 1999-03-30 2009-03-18 東レエンジニアリング株式会社 高周波域のアコースティックエミションの検出方法および検出素子
US6894425B1 (en) * 1999-03-31 2005-05-17 Koninklijke Philips Electronics N.V. Two-dimensional ultrasound phased array transducer
JP2001128980A (ja) * 1999-11-04 2001-05-15 Olympus Optical Co Ltd 機械走査式超音波探触子
US6515402B2 (en) * 2001-01-24 2003-02-04 Koninklijke Philips Electronics N.V. Array of ultrasound transducers
JP3611796B2 (ja) * 2001-02-28 2005-01-19 松下電器産業株式会社 超音波送受波器、超音波送受波器の製造方法及び超音波流量計
US6551248B2 (en) * 2001-07-31 2003-04-22 Koninklijke Philips Electronics N.V. System for attaching an acoustic element to an integrated circuit
JP2003284182A (ja) * 2002-03-25 2003-10-03 Osaka Industrial Promotion Organization 超音波センサ素子と超音波アレイセンサ装置とそれらの共振周波数の調整方法
KR20020050197A (ko) * 2002-05-06 2002-06-26 고도영 피에조 필름을 이용한 볼펜형 초음파 신호 발생 장치
US20060006765A1 (en) * 2004-07-09 2006-01-12 Jongtae Yuk Apparatus and method to transmit and receive acoustic wave energy

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4642508A (en) * 1984-03-09 1987-02-10 Kabushiki Kaisha Toshiba Piezoelectric resonating device
US6341408B2 (en) * 1996-11-26 2002-01-29 Thomson-Csf Method of manufacturing a multiple-element acoustic probe comprising a common ground electrode
US6685657B2 (en) * 1998-11-20 2004-02-03 Joie P. Jones Methods for selectively dissolving and removing materials using ultra-high frequency ultrasound
US6396199B1 (en) * 1999-07-02 2002-05-28 Prosonic Co., Ltd. Ultrasonic linear or curvilinear transducer and connection technique therefore
US6891314B2 (en) * 2001-08-22 2005-05-10 Fuji Xerox Co., Ltd Lattice array-structured piezoelectric actuator and method for producing the same

Cited By (72)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8482436B2 (en) 2002-11-04 2013-07-09 P Tech, Llc. Drag modification system
US20070158502A1 (en) * 2002-11-04 2007-07-12 Bonutti Peter M Ultrasonic communication and drag modification
US7990287B2 (en) 2002-11-04 2011-08-02 P Tech, Llc. Ultrasonic drag modulation
US9581179B2 (en) 2002-11-04 2017-02-28 P Tech, Llc Systems for modifying a fluid flow of a vehicle
US20100276006A1 (en) * 2002-11-04 2010-11-04 Bonutti Peter M Ultrasonic drag modulation
US7755519B2 (en) 2002-11-04 2010-07-13 P Tech, Llc. Ultrasonic communication and drag modification
US20080165620A1 (en) * 2005-07-20 2008-07-10 Denso Corporation Obstacle sensor having supersonic sensor
US7420876B2 (en) 2005-07-20 2008-09-02 Denso Corporation Obstacle sensor having supersonic sensor
US7555955B2 (en) 2006-01-11 2009-07-07 Denso Corporation Ultrasonic sensor
US20070157731A1 (en) * 2006-01-11 2007-07-12 Denso Corporation Ultrasonic sensor
US7730785B2 (en) 2006-04-26 2010-06-08 Denso Corporation Ultrasonic sensor and manufacture method of the same
US20070251324A1 (en) * 2006-04-26 2007-11-01 Denso Corporation Ultrasonic sensor and manufacture method of the same
US7638931B2 (en) * 2006-10-13 2009-12-29 Denso Corporation Resin substrate and ultrasonic sensor using the same
US20080088206A1 (en) * 2006-10-13 2008-04-17 Denso Corporation Resin substrate and ultrasonic sensor using the same
US20090071255A1 (en) * 2007-06-12 2009-03-19 Denso Corporation Ultrasonic sensor and self diagnostic method of the same
US8020447B2 (en) 2007-06-12 2011-09-20 Denso Corporation Ultrasonic sensor and self diagnostic method of the same
US7821872B2 (en) 2007-08-31 2010-10-26 Denso Corporation Method for ultrasonic wave transmission and apparatus for ultrasonic wave transmission
US7714482B2 (en) 2007-09-28 2010-05-11 Denso Corporation Ultrasonic sensor
US20090085439A1 (en) * 2007-09-28 2009-04-02 Denso Corporation Ultrasonic sensor
US20100275675A1 (en) * 2007-12-05 2010-11-04 Heikki Seppa Device for measuring pressure, variation in acoustic pressure, a magnetic field, acceleration, vibration, or the composition of a gas
US8850893B2 (en) * 2007-12-05 2014-10-07 Valtion Teknillinen Tutkimuskeskus Device for measuring pressure, variation in acoustic pressure, a magnetic field, acceleration, vibration, or the composition of a gas
US9462995B2 (en) 2010-03-19 2016-10-11 Seiko Epson Corporation Biological testing device including ultrasonic wave transmitting/receiving part
US9456801B2 (en) 2010-03-19 2016-10-04 Seiko Epson Corporation Biological testing device
US8546997B2 (en) * 2010-03-19 2013-10-01 Seiko Epson Corporation Ultrasonic sensor
US20110227449A1 (en) * 2010-03-19 2011-09-22 Seiko Epson Corporation Ultrasonic sensor
US20140276080A1 (en) * 2010-04-27 2014-09-18 Seiko Epson Corporation Ultrasonic sensor and electronic device
US10512453B2 (en) * 2010-04-27 2019-12-24 Seiko Epson Corporation Ultrasonic sensor and electronic device
US20130208572A1 (en) * 2010-07-30 2013-08-15 Koninklijke Philips Electronics N.V. Thin film ultrasound transducer
US9440258B2 (en) * 2010-07-30 2016-09-13 Koninklijke Philips Electronics N.V. Thin film ultrasound transducer
US9348027B2 (en) 2011-06-13 2016-05-24 Denso Corporation Ultrasonic sensor device
US9207216B2 (en) * 2011-10-21 2015-12-08 Riso Kagaku Corporation Ultrasonic sensor having trasmitting and receiving horns
US20130098157A1 (en) * 2011-10-21 2013-04-25 Riso Kagaku Corporation Ultrasonic sensor
US10040098B2 (en) 2012-03-30 2018-08-07 Seiko Epson Corporation Ultrasonic transducer element chip, probe, electronic instrument, and ultrasonic diagnostic device
US9554775B2 (en) 2012-03-30 2017-01-31 Seiko Epson Corporation Ultrasonic transducer element chip, probe, electronic instrument, and ultrasonic diagnostic device
US20160027424A1 (en) * 2013-04-24 2016-01-28 Murata Manufacturing Co., Ltd. Ultrasonic wave generation apparatus
US10074352B2 (en) * 2013-04-24 2018-09-11 Murata Manufacturing Co., Ltd. Ultrasonic wave generation apparatus
CN103770701A (zh) * 2013-05-15 2014-05-07 宁波保税区攀峒信息科技有限公司 一种特定物体近距离视觉盲区人体探测方法及装置
US20160139250A1 (en) * 2013-06-20 2016-05-19 Robert Bosch Gmbh Surroundings-sensing device having a modular ultrasonic transducer, and motor vehicle having such a surroundings-sensing device
US10707407B2 (en) 2013-11-20 2020-07-07 Seiko Epson Corporation Ultrasonic device, method for manufacturing the same, electronic device and ultrasonic imaging device
US9818929B2 (en) 2013-11-20 2017-11-14 Seiko Epson Corporation Ultrasonic device, method for manufacturing the same, electronic device and ultrasonic imaging device
US10252296B2 (en) 2014-03-10 2019-04-09 Seiko Epson Corporation Ultrasonic sensor
US9987663B2 (en) * 2014-03-10 2018-06-05 Seiko Epson Corporation Ultrasonic sensor
US11167314B2 (en) 2014-03-10 2021-11-09 Seiko Epson Corporation Ultrasonic sensor
US20150258573A1 (en) * 2014-03-10 2015-09-17 Seiko Epson Corporation Ultrasonic sensor
US11712718B2 (en) 2014-03-10 2023-08-01 Seiko Epson Corporation Ultrasonic sensor
US20160013394A1 (en) * 2014-07-11 2016-01-14 Microtech Medical Technologies Ltd. Multi-cell transducer
US10847708B2 (en) * 2014-07-11 2020-11-24 Microtech Medical Technologies Ltd. Multi-cell transducer
US11800806B2 (en) * 2014-07-11 2023-10-24 Microtech Medical Technologies Ltd. Method for manufacturing a multi-cell transducer
US20210043825A1 (en) * 2014-07-11 2021-02-11 Microtech Medical Technologies Ltd. Multi-cell transducer
US9818926B2 (en) * 2014-07-31 2017-11-14 Seiko Epson Corporation Ultrasonic device and probe as well as electronic apparatus and ultrasonic imaging apparatus
US20160036412A1 (en) * 2014-07-31 2016-02-04 Seiko Epson Corporation Ultrasonic device and probe as well as electronic apparatus and ultrasonic imaging apparatus
US11917922B2 (en) * 2016-04-27 2024-02-27 Seiko Epson Corporation Mounting structure, ultrasonic device, ultrasonic probe, ultrasonic apparatus, and electronic apparatus
US10929633B2 (en) 2016-09-18 2021-02-23 Boe Technology Group Co., Ltd. Fingerprint identification device, touch display panel, and method for driving fingerprint identification device
US20200186937A1 (en) * 2016-12-08 2020-06-11 Bae Systems Plc Electroacoustic transducer array
US11800295B2 (en) * 2016-12-08 2023-10-24 Bae Systems Plc Electroacoustic transducer
US20200186936A1 (en) * 2016-12-08 2020-06-11 Bae Systems Plc Electroacoustic transducer
US11666239B2 (en) 2017-03-14 2023-06-06 University Of Connecticut Biodegradable pressure sensor
US11179748B2 (en) 2017-05-09 2021-11-23 Seiko Epson Corporation Mounting structure, ultrasonic device, ultrasonic probe, ultrasonic apparatus, and electronic apparatus
GB2564914B (en) * 2017-07-19 2022-08-31 Bae Systems Plc Electroacoustic transducer array
US11181627B2 (en) * 2018-02-05 2021-11-23 Denso Corporation Ultrasonic sensor
CN109150127A (zh) * 2018-07-27 2019-01-04 开元通信技术（厦门）有限公司 薄膜体声波谐振器及其制作方法、滤波器
CN112805843A (zh) * 2018-08-01 2021-05-14 艾科索成像公司 用于集成具有混合触点的超声换能器的系统和方法
US20210151661A1 (en) * 2018-08-01 2021-05-20 Exo Imaging, Inc. Systems and methods for integrating ultrasonic transducers with hybrid contacts
CN111208498A (zh) * 2018-11-22 2020-05-29 精工爱普生株式会社 超声波元件及超声波装置
US11678989B2 (en) * 2019-03-01 2023-06-20 University Of Connecticut Biodegradable piezoelectric nanofiber scaffold for bone or tissue regeneration
US11826495B2 (en) 2019-03-01 2023-11-28 University Of Connecticut Biodegradable piezoelectric ultrasonic transducer system
US11445304B2 (en) 2019-04-05 2022-09-13 Denso Corporation Ultrasonic sensor
US11667247B2 (en) * 2019-07-10 2023-06-06 Denso Corporation Ultrasonic sensor
US20210009046A1 (en) * 2019-07-10 2021-01-14 Denso Corporation Ultrasonic sensor
CN112887881A (zh) * 2019-11-29 2021-06-01 精工爱普生株式会社 超声波设备
US11910720B2 (en) 2019-12-26 2024-02-20 Seiko Epson Corporation Piezoelectric device and MEMS device
US11745001B2 (en) 2020-03-10 2023-09-05 University Of Connecticut Therapeutic bandage

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KR100693401B1 (ko) 2007-03-09
US7329975B2 (en) 2008-02-12
CN100568020C (zh) 2009-12-09
JP4513596B2 (ja) 2010-07-28
DE102005040081A1 (de) 2006-03-16
US20080116765A1 (en) 2008-05-22
FR2874780B1 (fr) 2011-11-11
KR20060050660A (ko) 2006-05-19
US20070040477A1 (en) 2007-02-22
DE102005040081B4 (de) 2012-06-14
FR2874780A1 (fr) 2006-03-03
CN1740814A (zh) 2006-03-01
US7525237B2 (en) 2009-04-28
JP2006094459A (ja) 2006-04-06

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