Abstract: Ultrasonic sensor (1) includes piezoelectric element (7), first acoustic matching layer (2), and second acoustic matching layer (5) which are laminated and bonded together, piezoelectric element (7) having a rectangular bonding surface. First acoustic matching layer (2), which is adjacent to piezoelectric element (7), is bonded to piezoelectric element (7) using thermoplastic resin injected from a thickness direction of first acoustic matching layer (2) in a manner that a flow direction of the thermoplastic resin matches a longitudinal direction of piezoelectric element (7). With this configuration, ultrasonic sensor (1) that exhibits excellent temperature characteristics against such as thermal shock is provided.

Abstract: An ultrasonic sensor that is less affected by humidity change is obtained. Ultrasonic sensor (1) is configured by sequentially laminating piezoelectric element (2), metal housing (3), first acoustic matching layer (4), and second acoustic matching layer (5). First acoustic matching layer (4) adjacent to piezoelectric element (2) with metal housing (3) interposed therebetween includes a thermoplastic resin and an inorganic filler. The weight fraction of the inorganic filler in first acoustic matching layer (4) is set to less than or equal to 30% and the weight fraction of the hollow structure filler in the inorganic filler is set to less than or equal to 50%.

Abstract: There are provided piezoelectric element, case having conductivity, first acoustic matching layer bonded on case, and second acoustic matching layer stacked on and bonded to first acoustic matching layer. A joining part between first acoustic matching layer and second acoustic matching layer is located inside an outer periphery of a joining surface of first acoustic matching layer that is joined to second acoustic matching layer. This configuration can prevent indirect wave generated in first acoustic matching layer from propagating to second acoustic matching layer, and can therefore reduce reverberation of an ultrasonic wave.

Abstract: Ultrasonic sensor (1) includes piezoelectric element (7), first acoustic matching layer (2), and second acoustic matching layer (5) which are laminated and bonded together, piezoelectric element (7) having a rectangular bonding surface. First acoustic matching layer (2), which is adjacent to piezoelectric element (7), is bonded to piezoelectric element (7) using thermoplastic resin injected from a thickness direction of first acoustic matching layer (2) in a manner that a flow direction of the thermoplastic resin matches a longitudinal direction of piezoelectric element (7). With this configuration, ultrasonic sensor (1) that exhibits excellent temperature characteristics against such as thermal shock is provided.

Abstract: An ultrasonic transceiver includes a case having conductivity, a piezoelectric body having a piezoelectric electrode, and an adhesive member that bonds the case to the piezoelectric body. The adhesive member includes an adhesive and conductive particles, and secures electrical continuity between the case and the piezoelectric electrode. An adhesive layer formed of the adhesive member provided between the case and the piezoelectric electrode has a thickness equal to or less than a particle diameter of the conductive particles.

Abstract: An ultrasonic transceiver includes: a piezoelectric body including opposing surfaces having a first electrode and a second electrode respectively, piezoelectric body being segmented into a plurality of elements by a groove recessed from a surface having first electrode among the opposing surfaces; conductor electrically connected to first electrode on each of elements. The ultrasonic transceiver further includes reinforcement section provided in a part of second electrode, the part corresponding to a bottom of the groove. With this configuration, a decrease in a strength of piezoelectric body in the bottom of the groove, which is caused by a groove provided in piezoelectric body, can be prevented and occurrence of a crack can be prevented.

Abstract: An ultrasonic sensor includes metal member having flat plate, piezoelectric element bonded to first surface of flat plate, first acoustic matching layer adhered to second surface of flat plate, and adhesive that adheres first acoustic matching layer to flat plate. First acoustic matching layer of the ultrasonic sensor has opening on a surface adhered to flat plate and void that communicates with opening, in which adhesive is filled in void, adhesive solidifies in void, and thus an anchor effect can be obtained.

Abstract: An ultrasonic transceiver includes: piezoelectric body including opposing surfaces having first electrode and second electrode respectively, piezoelectric body being segmented into a plurality of elements by groove recessed from a surface having first electrode among the opposing surfaces; conductor electrically connected to first electrode on each of elements. The ultrasonic transceiver further includes reinforcement section provided in a part of second electrode, the part corresponding to a bottom of groove. With this configuration, a decrease in a strength of piezoelectric body in the bottom of groove, which is caused by groove provided in piezoelectric body, can be prevented and occurrence of a crack can be prevented.