Abstract:
A stress-isolated MEMS device (14) includes a platform (26) suspended over a substrate wafer (24). In one embodiment, the platform (26) is suspended by springs (38), but other suspension techniques may also be used. A transducer (28) is formed over the platform (26). The transducer (28) includes immovable portions (50) and movable portions (52). The transducer (28) and platform (26) are sealed within a cavity (62) formed within a cap support (30) between a cap wafer (32) and the substrate wafer (24). A leadframe (22) is affixed to the substrate wafer (24). The cap wafer (32) and other portions of the device (14) become embedded in a package material (20) so that a substantially solid boundary forms between the cap wafer (32) and the package material (20).
Abstract:
A microelectromechanical systems (MEMS) sensor (52) includes a substrate (62) a movable element (58) spaced apart from the substrate (62), suspension anchors (66, 68, 70, 72) formed on the substrate (62), and compliant members (74) interconnecting the movable element (58) with the suspension anchors. The MEMS sensor (52) further includes fixed fingers (76) and fixed finger anchors (78) attaching the fixed fingers (76) to the substrate (62). The movable element (58) includes openings (64). At least one of the suspension anchors resides in at least one of the multiple openings (64) and pairs (94) of the fixed fingers (76) reside in other multiple openings (64). The MEMS sensor (52) is symmetrically formed, and a location of the fixed finger anchors (78) defines an anchor region (103) within which the suspension anchors (66, 68, 70, 72) are positioned.
Abstract:
A microelectromechanical systems (MEMS) component 20 includes a portion 32 of a MEMS structure 30 formed on a semiconductor substrate 34 and a portion 36 of the structure 30 formed in a non-semiconductor substrate 22. The non-semiconductor substrate 22 is in fixed communication with the semiconductor substrate 34 with the portion 32 of the MEMS structure 30 being interposed between the substrates 34 and 22. A fabrication method 96 entails utilizing semiconductor thin-film processing techniques to form the portion 32 on the semiconductor substrate 34, and utilizing a lower cost processing technique to fabricate the portion 36 in the non-semiconductor substrate 22. The portions 32 and 36 are coupled to yield the MEMS structure 30, and the MEMS structure 30 can be attached to another substrate as needed for additional functionality.
Abstract:
A differential piezoelectric sensor (20) includes a suspended structure (24) coupled to a substrate (22). The suspended structure (24) has at least one location (44) in a first stress state (70) and at least one location (46) in a second stress state (72) when the suspended structure (24) is in a stress position (69). Piezoelectric elements (26) are located on the suspended structure (24) at the locations (44), each producing a signal (78) in response to mechanical stress (68) experienced by the suspended structure (24). In addition, piezoelectric elements (28) are formed on the suspended structure (24) at the locations (46), each producing a signal (80) in response to the mechanical stress (68). The piezoelectric elements (26, 28) are electrically connected to combine the signals (78, 80) so as to obtain a signal (76) representative of the mechanical stress (68) experienced by the suspended structure (24).