Ultrasonic probe, ultrasonic diagnostic apparatus, and method for manufacturing backing material

Abstract

An ultrasonic probe includes: a piezoelectric element; and a backing material including a matrix resin and thermally conductive particles, arranged on one direction side with respect to the piezoelectric element, wherein a ratio of thermal conductivity of the backing material in a thickness direction to the thermal conductivity of the backing material in a horizontal direction is 3 or more.

What is claimed is: 
     
         1 . An ultrasonic probe comprising:
 a piezoelectric element; and   a backing material including a matrix resin and thermally conductive particles, arranged on one direction side with respect to the piezoelectric element, wherein   a ratio of thermal conductivity of the backing material in a thickness direction to the thermal conductivity of the backing material in a horizontal direction is 3 or more.   
     
     
         2 . The ultrasonic probe according to  claim 1 , wherein
 the backing material has a region where the thermally conductive particles are aggregated and a region where the thermally conductive particles are not aggregated, and the thermally conductive particles are oriented in the thickness direction of the backing material.   
     
     
         3 . The ultrasonic probe according to  claim 1 , wherein a ratio of sound velocity of the backing material in the thickness direction to the sound velocity of the backing material in the horizontal direction is 0.5 or more. 
     
     
         4 . The ultrasonic probe according to  claim 1 , wherein the thermal conductivity of the backing material in the thickness direction is 2.0 W/mk or more, and the thermal conductivity of the backing material in the horizontal direction is 2.0 W/mk or more. 
     
     
         5 . The ultrasonic probe according to  claim 1 , wherein the matrix resin has a glass transition temperature (Tg) of 30° C. or higher and 200° C. or lower. 
     
     
         6 . The ultrasonic probe according to  claim 1 , wherein the backing material contains non-thermally conductive particles. 
     
     
         7 . The ultrasonic probe according to  claim 6 , wherein the non-thermally conductive particles are composite particles. 
     
     
         8 . An ultrasonic diagnostic apparatus comprising the ultrasonic probe according to  claim 1 . 
     
     
         9 . A method for manufacturing a backing material used for an ultrasonic probe, the method comprising:
 mixing a raw material of a matrix resin, thermally conductive particles, and non-thermally conductive particles to prepare a mixture; and   molding the mixture while the mixture is pressurized and heated to form a backing material, wherein   the thermally conductive particles are oriented in a thickness direction of the backing material.   
     
     
         10 . The method for manufacturing a backing material according to  claim 9 , wherein a ratio of thermal conductivity of the backing material in the thickness direction to the thermal conductivity of the backing material in a horizontal direction is 3 or more. 
     
     
         11 . The method for manufacturing a backing material according to  claim 9 , wherein a ratio of sound velocity of the backing material in the thickness direction to the sound velocity of the backing material in a horizontal direction is 0.5 or more. 
     
     
         12 . The method for manufacturing a backing material according to  claim 9 , wherein the raw material of the matrix resin contains powder particles. 
     
     
         13 . The method for manufacturing a backing material according to  claim 9 , wherein the raw material of the matrix resin contains powder particles having a number average particle size of 10 μm or more and 200 μm or less.