Low Pressure Sensor and Flow Sensor

摘要

A device/method for sensing a physical parameter, including a sensor die and a stress-sensitive circuit. The sensor die includes a semiconductor substrate and a cavity that creates an elastic element that bends in response to the physical parameter exerted on the sensor die. The elastic element includes at least at least one rigid island formed within the cavity, a thin area surrounding the at least one rigid island and having smaller thickness than the rigid island, and at least one stress concentrator at least partially formed in the thin area of the elastic element on the side of the substrate opposite the cavity. The stress-sensitive circuit includes at least one stress-sensitive component formed in the thin area of the elastic element. The at least one stress concentrator increases stress in the locations of the at least one stress-sensitive component resulting in an increase of the device sensitivity to the physical parameter.

主权项

1. A device for sensing a physical parameter, comprising:
a sensor die comprising:
a substrate made of a semiconductor material, the substrate having a first side, a second side substantially parallel to the first side, and a thickness defined by a distance from the first side to the second side; anda cavity formed on the second side of the sensor die creating an elastic element of the sensor die configured to bend in response to the physical parameter exerted on the sensor die, the elastic element comprising:
at least one rigid island formed within the cavity and having a thickness;a thin area surrounding the at least one rigid island and having a thickness smaller than the rigid island thickness; andat least one stress concentrator at least partially formed in the thin area of the elastic element on the first side of the substrate; and a stress-sensitive circuit including at least one stress-sensitive component formed in the thin area of the elastic element, the stress-sensitive circuit configured to output a signal proportional to the physical parameter, wherein the at least one stress concentrator is configured to increase stress in the locations of the at least one stress-sensitive component resulting in an increase of the device sensitivity to the physical parameter.