Murata Manufacturing Co., Ltd.

Masaharu Kota

Jiro Inoue

Koichi Watanabe

Chitaka Ochiai

Kazuya Nakatera

Junshi Ohta

An ultrasonic sensor has a built-in temperature compensation capacitor housed in a casing and facilitates an inside-the-casing lead-wire bonding connection process and a connection verifying process while increasing reliability. The ultrasonic sensor is provided with a piezoelectric vibration element and a capacitor for temperature compensation capacitor both housed in a casing. The temperature compensation capacitor includes a pair of electrodes located on one common surface of a dielectric body thus allowing the ultrasonic sensor to be electrically connected to lead wires on the one common surface.

Ultrasonic sensor with temperature compensation capacitor

An ultrasonic sensor (21) includes a case consisting of a case body (21) and a base (23), a piezoelectric diaphragm (25) which is arranged in the case, a conical vibrator (32) which is bonded to an ultrasonic transmitting/receiving side of the piezoelectric diaphragm (25), and a tubular member (24) which is arranged in front of the vibrator (32) for guiding ultrasonics.

Ultrasonic sensor

An ultrasonic transducer comprises a diaphragm formed by a metal plate provided with a bulged portion in its center and a piezoelectric element bonded to the inner surface of the bulged portion thereby to make the diaphragm vibrate in a bending mode. A node line is present outside the bulged portion in vibration of the diaphragm, and the diaphragm is sandwiched by first and second elastic members along the node line. The first and second elastic members are held between a case and a base fixed thereto so that the diaphragm is elastically retained through the first and second elastic members.

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Nagaokakyo, Japan

Masaharu Kota