Infrared thermal sensor with beams having different widths

摘要

An infrared thermal sensor (10) for detecting infrared radiation is described. It comprises a substrate (1) and a cap structure (2) together forming a sealed cavity (3). A membrane (4) is suspended therein by a plurality of beams (5), each beam comprising at least one thermocouple (6) arranged therein or thereon for measuring a temperature difference (”T) between the membrane and the substrate. At least two beams have a different length (L) and each of the thermocouples have a substantially same constant width to length ratio such that the thermal resistance measured between the membrane and the substrate is substantially constant for each beam (5), and such that the electrical resistance measured between the membrane and the substrate is substantially constant for each beam. The beams may be linear, and be oriented in a non-radial direction.