Key structure

Abstract

A key structure includes a membrane circuit board, an elastic element and a high impedance layer. The membrane circuit board includes a lower plate, an upper plate, a spacer plate and a circuit layer. The upper plate is located over the lower plate. The upper plate has an opening through the upper plate. The spacer plate is arranged between the lower plate and the upper plate. The circuit layer is arranged between the spacer plate and the upper plate. The elastic element is disposed on the membrane circuit board and substantially aligned with opening. The high impedance layer is disposed on a bottom surface of a bottom part of the elastic element and disposed within the opening of the upper plate. The high impedance layer is in contact with a part of the circuit layer.

Dependencies are inferred from the claim text.