Ultrasound vibration device, method of manufacturing ultrasound vibration device, and ultrasound medical apparatus

1. An ultrasound vibration device comprising a stacked transducer in which a plurality of piezoelectric single crystal element layers are stacked between two metal blocks, wherein

at least each of the plurality of piezoelectric single crystal element layers is fusion-bonded relative to a stack direction by bonding metal having a melting point corresponding to half a Curie point of the plurality of piezoelectric single crystal element layers or below.

2. The ultrasound vibration device according to claim 1 , wherein the bonding metal constitutes a plurality of electrode layers stacked among the plurality of piezoelectric single crystal element layers.

3. The ultrasound vibration device according to claim 1 , wherein a plurality of metallic spacers having a predetermined thickness are stacked among the plurality of the piezoelectric single crystal element layers, and the plurality of metallic spacers and the plurality of piezoelectric single crystal element layers are fusion-bonded relative to the stack direction by the bonding metal, so that the plurality of metallic spacers constitute the plurality of electrode layers stacked among the plurality of the piezoelectric single crystal element layers.

4. The ultrasound vibration device according to claim 1 , comprising a current-carrying portion electrically connecting positive electrodes with one another or negative electrodes with one another of the plurality of electrode layers, wherein

a side face of the stacked transducer where the current-carrying portion is electrically connected to the positive electrodes or the negative electrodes is formed as a plane.

5. The ultrasound vibration device according to claim 1 , wherein the plurality of piezoelectric single crystal element layers are formed with lithium niobate, and AuSn eutectic solder or non-lead solder having a melting point corresponding to half a Curie point of the lithium niobate or below is used as the bonding metal.

6. A method of manufacturing the ultrasound vibration device according to claim 1 , comprising:

stacking a first metal block of the two metal blocks, a plurality of piezoelectric single crystal wafers, and a second metal block of the two metal blocks by providing the bonding metal therebetween respectively;

forming an integrated block body by slowly cooling a stacked body constituted by the first metal block, the plurality of piezoelectric single crystal wafers, the second metal block and the bonding metal after heating the stacked body to be at the melting point of the bonding metal to fusion-bond the first metal block, the plurality of piezoelectric single crystal wafers and the second metal block in a stack direction by the bonding metal;

cutting out a plurality of columnar bodies from the bonded block body by machining; and

machining a horn for amplifying ultrasound vibration on a portion of the first metal block of the columnar body.

7. The method of manufacturing the ultrasound vibration device according to claim 6 , wherein the bonding metal is provided on one face of the first metal block, the plurality of piezoelectric single crystal wafers or the second metal block by screen printing.

8. The method of manufacturing the ultrasound vibration device according to claim 6 , wherein the bonding metal is a metallic ribbon and is provided respectively between the first metal block, the plurality of piezoelectric single crystal wafers and the second metal block.

9. An ultrasound medical apparatus comprising:

the ultrasound vibration device according to claim 1 ; and

a probe distal end portion to which ultrasound vibration generated by the ultrasound vibration device is transmitted and which treats living tissue.