Ultrasonic device and probe as well as electronic apparatus and ultrasonic imaging apparatus

1. An ultrasonic device, comprising:

a base;

ultrasonic transducer elements that are arranged in an array on the base and that have respective vibration films;

an acoustic matching layer formed on the individual ultrasonic transducer elements;

electric conductors that are arranged between adjacent ultrasonic transducer elements of said ultrasonic transducer elements when viewed from above in a thickness direction of the base and that are connected to electrodes of said ultrasonic transducer elements;

protective films that are arranged on the electric conductors and that have smaller moisture permeability than the acoustic matching layer; and

wall portions that are arranged on the protective films and that separate portions of the acoustic matching layer that are respectively located on the adjacent ultrasonic transducer elements from each other at least in a part of a height range with respect to a height direction from the base, the wall portions having an acoustic impedance that is different from an acoustic impedance of the acoustic matching layer.

2. The ultrasonic device according to claim 1 , wherein the protective films are arranged at positions on the electric conductors where the protective films sandwich portions of surfaces of the electric conductors when viewed from above in the thickness direction of the base, and

the ultrasonic device further comprises:

an interconnect that is disposed so as to be surrounded by the portions of the surfaces of the electric conductors, the protective films that are arranged at positions where the protective films sandwich the portions of the surfaces of the electric conductors, and the corresponding wall portion.

3. The ultrasonic device according to claim 1 , wherein a cavity is formed in each of the wall portions.

4. The ultrasonic device according to claim 3 ,

wherein the cavity opens in a top surface of the wall portion that is farthest from the base with respect to the height direction, and a bottom of the cavity is located at a predetermined height position from the protective film with respect to the height direction.

5. The ultrasonic device according to claim 1 ,

wherein the protective films are oxide films or nitride films of an inorganic material.

6. The ultrasonic device according to claim 5 ,

wherein the protective films are formed of Al 2 O 3 .

7. The ultrasonic device according to claim 1 ,

wherein the wall portions are formed of a material having smaller moisture permeability than the acoustic matching layer.

8. The ultrasonic device according to claim 7 ,

wherein the wall portions are formed of a permanent resist film.

9. The ultrasonic device according to claim 1 ,

wherein the wall portions divide the acoustic matching layer into portions each corresponding to a group of the ultrasonic transducer elements that are connected commonly to a single signal line.

10. The ultrasonic device according to claim 9 ,

wherein the wall portions separate portions of the acoustic matching layer from each other, the portions being respectively located on the adjacent ultrasonic transducer elements contained in the group of the ultrasonic transducer elements that are connected commonly to the signal line.

11. A probe, comprising:

the ultrasonic device according to claim 1 ; and

a housing that supports the ultrasonic device.

12. An electronic apparatus, comprising:

the ultrasonic device according to claim 1 ; and

a processor that is connected to the ultrasonic device and that processes an output from the ultrasonic device.

13. An ultrasonic imaging apparatus, comprising:

the ultrasonic device according to claim 1 ; and

a display device that displays an image generated based on an output from the ultrasonic device.

14. An ultrasonic device, comprising:

a base;

ultrasonic transducer elements that are arranged in an array on the base and that have vibration films;

an acoustic matching layer formed on the ultrasonic transducer elements;

electric conductors that are arranged between adjacent ultrasonic transducer elements of said ultrasonic transducer elements;

protective films that are arranged on the electric conductors and that have smaller moisture permeability than the acoustic matching layer; and

wall portions that are arranged on the protective films and that separate adjacent portions of the acoustic matching layer from each other,

wherein an acoustic impedance of the wall portions is different from an acoustic impedance of the acoustic matching layer.