LOW-G MEMS ACCELERATION SWITCH

摘要

A motion-sensitive low-G MEMS acceleration switch, which is a MEMS switch that closes at low-g acceleration (e.g., sensitive to no more than 10 Gs), is proposed. Specifically, the low-G MEMS acceleration switch has a base, a sensor wafer with one or more proofmasses, an open circuit that includes two fixed electrodes, and a contact plate. During acceleration, one or more of the proofmasses move towards the base and connects the two fixed electrodes together, resulting in a closing of the circuit that detects the acceleration. Sensitivity to low-G acceleration is achieved by proper dimensioning of the proofmasses and one or more springs used to support the proofmasses in the switch.

主权项

1. A MEMS acceleration switch comprising:
a base; a first electrode coupled to the base; a second electrode coupled to the base and spaced apart from the first electrode; a sensor wafer comprising:
a proofmass formed in the sensor wafer by removing material from the sensor wafer all the way around the proofmass to form substantially thinner spring regions of the sensor wafer such that the proofmass is coupled to a surrounding portion of the sensor wafer only through the substantially thinner spring regions; and, a contact plate coupled to the sensor wafer adjacent the proofmass; wherein the base is coupled to the sensor wafer such that the contact plate forms a gap with the first and second electrodes but is designed to close the gap and electrically connect the first and second electrodes under acceleration.