Abstract: Embodiments of the disclosure provide a micromachined mirror assembly. The micromachined mirror assembly includes a micro mirror configured to tilt around an axis and a first and a second torsion beam each having a first and a second end. The second end of the first torsion beam and the second end of the second torsion beam are mechanically coupled to the micro mirror along the axis. The micromachined mirror assembly also includes a first DC voltage applied to the first end of the first torsion beam and a second DC voltage, different from the first DC voltage, is applied to the first end of the second torsion beam.

Abstract: Embodiments of the disclosure provide a mirror assembly for controlling optical directions in an optical sensing system. The mirror assembly may include a frame and a beam structure mechanically coupled to the frame. The beam structure may define a rotational axis. The mirror assembly may also include a micro mirror suspended by the beam structure. The mirror assembly may further include a plurality of piezoelectric actuators mechanically coupled to the frame and configured to rotate the micro mirror along the rotational axis. Each of the plurality of piezoelectric actuators may be disposed between the rotational axis and an outer edge of the frame.

Abstract: A piezoelectric actuator including an anchor, an elastic layer having a first end coupled to the anchor, and a piezoelectric layer on the elastic layer. The elastic layer includes a solid sublayer including an elastic material and a second sublayer including a plurality of cavities. The piezoelectric layer is on the second sublayer of the elastic layer and includes a top electrode, a bottom electrode, and a piezoelectric material layer between the top electrode and the bottom electrode.

Abstract: Embodiments of the disclosure provide a packaged micro-mirror for an optical sensing system. In some embodiments, the packaged micro-mirror may include a package substrate. In some embodiments, the packaged micro-mirror may include a micro-mirror die attached to the package substrate through a first die attach material and a second die attach material. In some embodiments, the first die attach material may have a first Young’s modulus and the second die attach material may have a second Young’s modulus higher than the first Young’s modulus. In some embodiments, at least one of the first die attach material or the second die attach material may be a conductive adhesive forming an electrical connection between the micro-mirror die and package substrate.

Abstract: Embodiments of the disclosure provide a micromachined mirror assembly. The micromachined mirror assembly includes a micro mirror configured to tilt around an axis and a first and a second torsion beam each having a first and a second end. The second end of the first torsion beam and the second end of the second torsion beam are mechanically coupled to the micro mirror along the axis. The micromachined mirror assembly also includes a first DC voltage applied to the first end of the first torsion beam and a second DC voltage, different from the first DC voltage, is applied to the first end of the second torsion beam.

Abstract: Methods and systems for using a MEMS mirror for steering a LiDAR beam and for minimizing statically emitted light from a LiDAR system are disclosed. A LiDAR system includes a light source that emits a light beam directed at a MEMS device. The MEMS device includes a manipulable mirror that reflects the emitted light beam in a scanning pattern. The MEMS device also includes a substrate positioned adjacent to and at least partially surrounding the mirror. An attenuation layer is disposed on a top surface of the substrate and is configured to attenuate light reflected by the substrate.

Abstract: Embodiments of the disclosure provide a micromachined mirror assembly. The micromachined mirror assembly includes a micro mirror configured to tilt around an axis and a first and a second torsion beam each having a first and a second end. The second end of the first torsion beam and the second end of the second torsion beam are mechanically coupled to the micro mirror along the axis. The micromachined mirror assembly also includes a first DC voltage applied to the first end of the first torsion beam and a second DC voltage, different from the first DC voltage, is applied to the first end of the second torsion beam.

Abstract: Embodiments of the disclosure provide a micromachined mirror assembly having multiple coating layers. In one example, the micromachined mirror assembly includes a micro mirror having a first thermal expansion coefficient, a reflective layer having a second thermal expansion coefficient, and a compensation layer having a third thermal expansion coefficient. The reflective layer is disposed on a top surface of the micro mirror and is reflective to incident light of the micromachined mirror assembly. The compensation layer is disposed on the reflective layer and is transparent to the incident light of the micromachined mirror assembly. The first thermal expansion coefficient is between the second thermal expansion coefficient and the third thermal expansion coefficient.

Abstract: Methods and systems for using a MEMS mirror for steering a LiDAR beam and for minimizing statically emitted light from a LiDAR system are disclosed. A LiDAR system includes a light source that emits a light beam directed at a MEMS device. The MEMS device includes a manipulable mirror that reflects the emitted light beam in a scanning pattern. The MEMS device also includes a substrate positioned adjacent to and at least partially surrounding the mirror. An attenuation layer is disposed on a top surface of the substrate and is configured to attenuate light reflected by the substrate.

Abstract: Embodiments of the disclosure provide a micromachined mirror assembly. The micromachined mirror assembly includes a micro mirror, a first suspended beam, a second suspended beam, a first actuator, and a second actuator. The micro mirror is configured to tilt around an axis. The first suspended beam and second suspended beam each is mechanically coupled to the micro mirror along the axis. The first actuator is mechanically coupled to the first suspended beam and configured to apply a first torsional stress around the axis to the first suspended beam. The second actuator is mechanically coupled to the second suspended beam and configured to apply a second torsional stress around the axis to the second suspended beam. the first torsional stress and second torsional stress have a magnitude difference.

Abstract: A micro-electromechanical system (MEMS) apparatus has an array of micro-mirrors and a control circuit for rotating the micro-mirrors synchronously at a resonant frequency. An array of heating resistors is used to heat the array of micro-mirrors compensate for changes in resonant frequency with temperature. A temperature sensor is mounted proximate the chip package for detecting a temperature proximate the array of micro-mirrors. A temperature control circuit, coupled to the temperature sensor and the array of heating resistors, provides current to the array of heating resistors in response to a change in temperature that will change the resonant frequency.

Abstract: A micro-electromechanical system (MEMS) apparatus has an array of micro-mirrors and a control circuit for rotating the micro-mirrors synchronously at a resonant frequency. The MEMS apparatus includes elements with different Coefficients of Thermal Expansion (CTE) for a die substrate coupled to the array of micro-mirrors, a die attach layer, a chip package coupled to the die substrate and a printed circuit board coupled to the chip package. The apparatus provides mechanisms for reducing changes in the resonant frequency due to changes in temperature causing stresses due to a mismatch between the CTE of the different elements. A thermoelectric cooler is used, along with the optional addition of heating resistors, additional pins to distribute stress, and the widened vias allowing room for the pins to bend and relieve stress on the chip package.

Abstract: Apparatus and methods for forming MEMS structures that minimize bending with temperature change due to differences in the coefficient of thermal expansion for different layers of the MEMS structures. In particular, shown is forming a compensating reflectivity coating on the underside of a suspended MEMS structure to offset bending by a reflectivity coating on a top side of the suspended MEMS structure. The reflectivity coating can be either a reflective coating, or a non-reflective (anti-reflective) coating. The method includes forming a cavity on a first wafer, forming the compensating reflective coating on a second wafer substrate that will become the suspended MEMS structure, then flipping the second wafer over and bonding the two wafers together.

Abstract: A method and mechanism for reducing changes in the resonant frequency of a MEMS mirror structure with temperature by reducing the bending of the structure due to CTE mismatches. A plurality of support pins are attached to the chip package for adding rigidity to the chip package. The added rigidity minimizes bending due to changes in temperature that cause stresses and bending due to differences in the CTE of the MEMS micro-mirror array substrate, the die attach bonding layer, the chip package and the PCB. Also, a plurality of vias provide bending space for a plurality of pins attached to the chip package. Thus, as the chip package expands or contracts with temperature, the pins move with the chip package, minimizing stresses that would affect the resonant frequency of the MEMS micro-mirror array.

Abstract: Embodiments provide a method and mechanism for reducing changes in the resonant frequency of a MEMS mirror structure with temperature due to a mismatch between the CTE of the MEMS die and the package substrate. A die attach layer with a low Young's modulus, such as less than 15,000 psi, is used to allow absorption of some of the stress due to the mismatch in the CTE of the MEMS die and the package substrate. In addition, in embodiments a thicker die attach layer than normal is used to absorb some of the stress, increasing the height of the die attach layer from the normal range around 25 ?m to between 50-150 ?m thick. In further embodiments a pattern of open cavities is etched in the bottom of the die substrate. The die substrate may be made thicker to provide room for the cavities.

Abstract: A method comprising: adhering a first surface of a mask to a carrier substrate via a first adhesive layer; forming a second adhesive layer on at least one of a second surface of the mask or a third surface of a wafer having a second alignment mark; bringing the carrier substrate and the wafer towards each other along a vertical axis such that the second surface of the mask and the third surface of the wafer is separated by an alignment gap based on a thickness of the second adhesive layer; performing an alignment operation based on imaging the first alignment mark and the second alignment mark; configuring the second surface of the mask to adhere to the third surface of the wafer via the second adhesive; and disconnecting the carrier substrate from the mask.

Abstract: Methods and systems for using a dual sided MEMS mirror for determining a direction of steered light are disclosed. In one example a MEMS package includes a substrate defining an aperture and a dual sided MEMS mirror is positioned over the aperture. A first surface of the MEMS mirror is used to steer a LiDAR beam that is used to perform LiDAR imaging of an area of interest. As the mirror is moved, a second surface of the mirror reflects a sensing beam onto a detector array. Data from the detector array is used to determine an orientation of the mirror which can then be used to determine a direction of the steered LiDAR beam. The MEMS package can form an enclosure for the MEMS mirror that includes a first and a second transparent window attached to two opposing surfaces of the substrate.

Abstract: A piezoelectric actuator including an anchor, an elastic layer having a first end coupled to the anchor, and a piezoelectric layer on the elastic layer. The elastic layer includes a solid sublayer including an elastic material and a second sublayer including a plurality of cavities. The piezoelectric layer is on the second sublayer of the elastic layer and includes a top electrode, a bottom electrode, and a piezoelectric material layer between the top electrode and the bottom electrode.

Abstract: Embodiments of the disclosure provide a mirror assembly for controlling optical directions in an optical sensing system. The mirror assembly may include a frame and a beam structure mechanically coupled to the frame. The beam structure may define a rotational axis. The mirror assembly may also include a micro mirror suspended by the beam structure. The mirror assembly may further include a plurality of piezoelectric actuators mechanically coupled to the frame and configured to rotate the micro mirror along the rotational axis. Each of the plurality of piezoelectric actuators may be disposed between the rotational axis and an outer edge of the frame.

Abstract: Embodiments of the disclosure provide a micromachined mirror assembly having a mirror-base layer, a first reflective layer on a top surface of the mirror-base layer, and a second reflective layer on a bottom surface of the mirror-base layer. In an example, the first reflective layer is reflective to incident light of the micromachined mirror assembly, and the first reflective layer and the second reflective layer are made of a same material and have same dimensions.