Patent ID: 8512251

Claim:
An ultrasound transducer comprising: a substrate; and a lower electrode layer, a lower insulating layer, an upper insulating layer, and an upper electrode layer laminated in order on the substrate, wherein the lower insulating layer and the upper insulating layer are arranged to be opposed to each other via an air gap section, are different in at least one of a material and thickness, and satisfy Equation 1 below: 1 K ⁢ ⁢ 1 ⁢ ∫ 0 T ⁢ ⁢ 1 ⁢ x × ρ ⁢ ⁢ 1 ⁢ ( x ) ⁢ ⁢ ⅆ x = 1 K ⁢ ⁢ 2 ⁢ ∫ 0 T ⁢ ⁢ 2 ⁢ y × ρ ⁢ ⁢ 2 ⁢ ( y ) ⁢ ⁢ ⅆ y where, K 1 represents a relative dielectric constant of the lower insulating layer, K 2 represents a relative dielectric constant of the upper insulating layer, T 1 represents layer thickness of the lower insulating layer, T 2 represents layer thickness of the upper insulating layer, ρ 1 ( x ) represents a charge density distribution in the lower insulating layer, x represents a distance from the lower electrode layer, ρ 2 ( y ) represents a charge density distribution in the upper insulating layer, and y represents a distance from the upper electrode layer.