Accelerometer including a decoupling structure for fixing the accelerometer on a package and a MEMS sensor chip for measuring an acceleration. The chip is supported by the decoupling structure and includes a sensor wafer layer of a semiconductor material. The decoupling structure forms a bottom portion for fixing the decoupling structure on the package and a top portion fixed to the sensor wafer layer so that the chip is arranged above the decoupling structure. A width of the top portion in a planar direction is smaller than a width of the bottom portion and/or the sensor wafer layer in the planar direction. The decoupling structure is made of the same semiconductor material as the sensor wafer layer. The centre point of the top portion is arranged in a central region of the bottom portion. The chip includes a hermetically closed cavity which includes a seismic mass of the chip.

A chip package includes a first die, a second die, a molding material, and a redistribution layer. The first die includes a first conductive pad. The second die is disposed on the first die and includes a second conductive pad. The molding material covers the first die and the second die. The molding material includes a top portion, a bottom portion, and an inclined portion adjoins the top portion and the bottom portion. The top portion is located on the second die, and the bottom portion is located on the first die. The redistribution layer is disposed along the top portion, the inclined portion, and the bottom portion. The redistribution layer is electrically connected to the first conductive pad and the second conductive pad.

The disclosure describes techniques to damp the proof mass motion of an accelerometer while achieving an underdamped resonator. In an example of an in-plane micro-electromechanical systems (MEMS) VBA, the proof mass may contain one or more damping combs that include one or more banks of rotor comb fingers attached to the proof mass. The rotor comb fingers may be interdigitated with stator comb fingers that are attached to fixed geometry. These damping comb fingers may provide air damping for the proof mass when the MEMS die is placed into a package containing a pressure above a vacuum. The geometry of the damping combs with a reduced air gap and large overlap area between the rotor comb fingers and stator comb fingers. The geometry of resonator of the VBA of this disclosure may be configured to avoid air damping.

Microelectronic assemblies, related devices and methods, are disclosed herein. In some embodiments, a microelectronic assembly may include a first microelectronic component having a first direct bonding region, wherein the first direct bonding region includes first metal contacts and a first dielectric material between adjacent ones of the first metal contacts; a second microelectronic component having a second direct bonding region, wherein the second direct bonding region includes second metal contacts and a second dielectric material between adjacent ones of the second metal contacts, wherein the first microelectronic component is coupled to the second microelectronic component by interconnects, and wherein the interconnects include individual first metal contacts coupled to respective individual second metal contacts; and a void between an individual first metal contact that is not coupled to a respective individual second metal contact, wherein the void is in the first direct bonding region.

A device includes a readout circuit coupled between an input node and an output node; a microelectromechanical systems (MEMS) device coupled to the input node; and a first charge controlled clamp circuit coupled between the input node and a first bias node.

A sensor module including a microelectromechanical systems (“MEMS”) gyroscope resonator and an accelerometer positioned adjacent the MEMS gyroscope resonator is disclosed herein. The MEMS gyroscope resonator and accelerometer can be co-fabricated on a sensor die and a control circuit can be electrically coupled to the sensor die. The control circuit can be configured to receive signals from and control the MEMS gyroscope resonator and the accelerometer. An interposer can be positioned between and mechanically coupled to the sensor module and a substrate, wherein the interposer is configured to relieve stresses imposed by an operating environment on the sensor module and the substrate.

An exemplary microelectromechanical system (MEMS) device comprises a plurality of stacked layers, including at least one layer that includes micromechanical components that respond to a force to be measured. Two of the layers may include respective first and second external electrical connection points. A plurality of conductive paths may be disposed in a continuous manner over an external surface of each of the plurality of layers between the first and second external electrical connection points.

A flip chip micromirror assembly comprising a micromirror chip that is flip chip mounted onto the circuit board via a bonding layer. The micromirror chip has a micromirror layer in which a micromirror is formed. The micromirror chip has a flip chip surface facing the electrode surface of the circuit board. The bonding layer includes conductive region(s) that electrically couples corresponding board electrodes with corresponding chip electrodes. However, the bonding layer is not interposed between the electrode surface of the circuit board and the micromirror itself. In other words, the bonding layer spaces the micromirror chip from the circuit board, and provides a gap underneath the micromirror between the micromirror chip and the circuit board. This gap is of sufficient thickness that the micromirror can be actuated with full movement without being mechanically obstructed by the circuit board.

Micromachined ultrasonic transducers integrated with complementary metal oxide semiconductor (CMOS) substrates are described, as well as methods of fabricating such devices. Fabrication may involve two separate wafer bonding steps. Wafer bonding may be used to fabricate sealed cavities in a substrate. Wafer bonding may also be used to bond the substrate to another substrate, such as a CMOS wafer. At least the second wafer bonding may be performed at a low temperature.

The disclosure describes techniques to adjust the geometry of a pendulous proof mass VBA to operate with sufficient signal-to-noise performance while avoiding nonlinear mechanical coupling at specified frequencies. The techniques of this disclosure include adding anchor support flexures to a resonator connection structure, adjusting shape, thickness, and the material of VBA components and of the VBA support structure to both control the frequency of any mechanical resonant modes and to adjust the mechanical mode frequencies away from desired operating frequencies and, in some examples, away from harmonics of desired operating frequencies.