Abstract: A MEMS inertial sensor is secured within a premolded-type package formed, at least in part, from a low moisture permeable molding material. Consequently, such a motion detector should be capable of being produced more economically than those using ceramic packages. To those ends, the package has at least one wall (having a low moisture permeability) extending from a leadframe to form a cavity, and an isolator (with a top surface) within the cavity. The MEMS inertial sensor has a movable structure suspended above a substrate having a bottom surface. The substrate bottom surface is secured to the isolator top surface at a contact area. In illustrative embodiments, the contact area is less than the surface area of the bottom surface of the substrate. Accordingly, the isolator forms a space between at least a portion of the bottom substrate surface and the package. This space thus is free of the isolator.

Abstract: Accelerometer offset is reduced by forming mass support structures within an inner periphery of the mass, affixing the mass support structures to the substrate by at least one anchor positioned near the mass' center of mass, and affixing the sensing fingers proximate to the anchor. The mass support structures can be affixed to the substrate using a single anchor or multiple anchors that are positioned close together. The sensing fingers can be affixed to the substrate or to the mass support structures. The mass is typically suspended from within its periphery but toward its outer periphery.

Abstract: An electro-mechanical micromachined structure uses bumpers to prevent contact between structures at different potentials. A beam is connected to one or more anchors by flexible suspensions, which permit the beam to move along a predetermined axis relative to one or more plates. The suspension includes at least one bumper positioned so that the bumper will contact another part of the suspension before the beam contacts the plates. The bumper is made from the same material as the suspension, during the same processing step. The bumper is positioned to take advantage of shrinkage or expansion of the beam during processing which forces the bumper closer to its contact point then would otherwise be possible.