Patent ID: 9344807
Filing Date: 2016-05-17
CPC Classification: H01L,H04R

Claim Text:
1. A capacitance-type transducer comprising: a substrate having a cavity; a vibrating electrode plate disposed above the substrate; a back plate disposed on the substrate; a fixed electrode plate disposed on the back plate opposite the vibrating electrode plate; a plurality of holes formed in the back plate and the fixed electrode plate; and a protrusion disposed on the back plate at a location opposing the vibrating electrode plate, wherein in a view from a direction perpendicular to an upper surface of the substrate, a shortest distance from a cross-sectional center of the protrusion to an edge of a hole adjacent to the protrusion is larger than a shortest distance from a center of a region that is surrounded by the holes but not provided with the protrusion to an edge of a hole in the periphery, and wherein in an edge of at least one hole among the holes adjacent to the protrusion, a portion of the edge in the vicinity of the protrusion is drawn toward the interior of the hole in comparison with another hole.