Ultrasonic transducer, method for making same, ultrasonic transducer array, and ultrasonic test apparatus

A manufacturing method for an ultrasound transducer comprising:

• forming a plurality of layers including a first conductive film, a first insulating film, a second insulating film, a second conductive film, and a third insulating film on a predetermined region on a substrate by patterning;
• and
• manufacturing a plurality of ultrasound transducers,
• wherein in a process the same as the patterning, on an outer region except the predetermined region on the substrate, a warpage prevention layer that reduces warpage of the substrate is formed in a predetermined pattern.

An ultrasonic examination apparatus comprising:

• an ultrasound probe having an ultrasound transducer built in;
• an ultrasonic transmitter/receiver circuit that transmits an ultrasound signal to the ultrasound probe and receives an ultrasound signal detected by the ultrasound probe;
• and
• an image producing unit that produces an image using an ultrasound signal received by the ultrasonic transmitter/receiver circuit,
• wherein the ultrasound probe is an ultrasound probe having an ultrasound transducer built in, the ultrasound transducer including:
• a substrate;
• a first conductive film formed on the substrate;
• a first insulating film and a second insulating film formed on the first conductive film;
• a cavity provided between the first insulating film and the second insulating film;
• a second insulating film formed on the second conductive film;
• a third insulating film covering the second conductive film;
• and
• a warpage prevention layer disposed between the substrate and the first conductive film, the warpage prevention layer preventing the substrate from being warped.