The electric wiring section where the signal pattern where the ultrasonic probe which relates to this invention, and has the plural vibrating elements where electromechanical coupling coefficient or sensitivity changes according to bias voltage the cMUT tip/chip the acoustic lens is provided on rear side of 26 where is provided on ultrasonic emission side of 20 which the ultra wave the sending and receiving wave is done and the aforementioned cMUT tip/chip 20 and the aforementioned cMUT tip/chip and 20 the backing layer from the margin of 22 which absorbs the propagation of the aforementioned ultra wave and the aforementioned cMUT tip/chip 20 is provided on the side of the aforementioned backing layer and 22 the electrode of the aforementioned cMUT tip/chip 20 is connected is arranged (flexible baseplate 72) with, the aforementioned cMUT tip/chip 20 and the aforementioned soundOn ultrasonic emission side of the aforementioned cMUT tip/chip 20, gland layer of gland electric potential (electric conduction membrane 76) is provided lens 26 and the aforementioned backing layer 22 and the aforementioned electric wiring section (flexible baseplate 72) the frame section which is housed (ultrasonic probe cover 25) with, in the ultrasonic probe 2 which it has.本発明に係る超音波探触子は、バイアス電圧に応じて電気機械結合係数または感度が変化する複数の振動要素を有し超音波を送受波するcMUTチップ20と、前記cMUTチップ20の超音波放射側に設けられる音響レンズ26と、前記cMUTチップ20の背面側に設けられ前記超音波の伝播を吸収するバッキング層22と、前記cMUTチップ20の周縁部から前記バッキング層22の側面に設けられ前記cMUTチップ20の電極と接続される信号パターンが配置される電気配線部(フレキシブル基板72)と、前記cMUTチップ20及び前記音響レンズ26及び前記バッキング層22及び前記電気配線部(フレキシブル基板72)を格納する筐体部(超音波探触子カバー25)と、を備える超音波探触子2において、前記cMUTチップ20の超音波放射側に、グランド電位のグランド層(導電膜76)が設けられる。
