Abstract:
A pressure sensor comprises a first substrate and a cap attached to the first substrate. The cap includes a processing circuit, a cavity and a deformable membrane separating the cavity and a port open to an outside of the pressure sensor. Sensing means are provided for converting a response of the deformable membrane to pressure at the port into a signal capable of being processed by the processing circuit. The cap is attached to the first substrate such that the deformable membrane faces the first substrate and such that a gap is provided between the deformable membrane and the first substrate which gap contributes to the port. The first substrate comprises a support portion the cap is attached to, a contact portion for electrically connecting the pressure sensor to an external device, and one or more suspension elements for suspending the support portion from the contact portion.
Abstract:
Methods for fabricating a hermetic seal to seal a portion of an apparatus, for example and without limitation, a portion having a MEMS sensor. One such method uses crimping devices to compress a seal in a cavity formed in a housing that includes a MEMS sensor attached to a stress isolator. Under such compression, the seal deforms to hermetically seal surfaces around the inside, outside and bottom of the stress isolator.
Abstract:
According to various embodiments, a dynamic pressure sensor includes a substrate, a reference volume formed in the substrate, a deflectable membrane sealing the reference volume, a deflection sensing element coupled to the membrane and configured to measure a deflection of the membrane, and a ventilation hole configured to equalize an absolute pressure inside the reference volume with an absolute ambient pressure outside the reference volume.
Abstract:
Sensor packages and manners of formation are described. In an embodiment, a sensor package includes a supporting die characterized by a recess area and a support anchor protruding above the recess area. A sensor die is bonded to the support anchor such that an air gap exists between the sensor die and the recess area. The sensor die includes a sensor positioned directly above the air gap.
Abstract:
A method of manufacturing a pressure sensor is provided. The method includes: providing a substrate, wherein a bottom electrode and a pressure sensing film are disposed on the substrate; forming an etch stop assembly on the pressure sensing film at a location corresponding to a pressure trench; forming a cover layer on the substrate covering the etch stop assembly and the pressure sensing film; forming a mask layer on the cover layer, wherein an opening of the mask layer is formed above the etch stop assembly and exposes a portion of the cover layer at the location corresponding to the pressure trench; etching the cover layer using the mask layer so as to form the pressure trench in the cover layer; removing the etch stop assembly at a bottom of the pressure trench; and removing the mask layer.
Abstract:
A method for forming a micro-electro mechanical system (MEMS) device is provided. The method includes bonding a semiconductor substrate with a carrier substrate through a dielectric layer and patterning the semiconductor substrate into multiple elements. The method also includes partially removing the dielectric layer to release some of the elements such that the released elements become one (or more) first movable element and one (or more) second movable element. The method further includes bonding a cap substrate with the semiconductor substrate to form a first closed chamber containing the first movable element and a second closed chamber containing the second movable element. In addition, the method includes opening the second closed chamber and sealing the second closed chamber after vacuumizing the second closed chamber such that the second closed chamber has a reduced pressure smaller than that of the first closed chamber.
Abstract:
Stress relief structures and methods that can be applied to MEMS sensors requiring a hermetic seal and that can be simply manufactured are disclosed. The system includes a sensor having a first surface and a second surface, the second surface being disposed away from the first surface, the second surface also being disposed away from a package surface and located between the first surface and the package surface, a number of support members, each support member extending from the second surface to the package surface, the support members being disposed on and operatively connected to only a portion of the second surface. The support member are configured to reduce stress produced by package-sensor interaction.
Abstract:
A MEMS capacitive transducer with increased robustness and resilience to acoustic shock. The transducer structure includes a flexible membrane supported between a first volume and a second volume, and at least one variable vent structure in communication with at least one of the first and second volumes. The variable vent structure includes at least one moveable portion which is moveable in response to a pressure differential across the moveable portion so as to vary the size of a flow path through the vent structure. The variable vent may be formed through the membrane and the moveable portion may be a part of the membrane, defined by one or more channels, that is deflectable away from the surface of the membrane. The variable vent is preferably closed in the normal range of pressure differentials but opens at high pressure differentials to provide more rapid equalisation of the air volumes above and below the membrane.
Abstract:
To provide a physical quantity sensor in which the influence of deformation of a package substrate on the measuring accuracy of a sensor element can be suppressed. A physical quantity sensor includes a sensor element that detects a predetermined physical quantity and outputs an electrical signal, a plurality of lead portions that are connected to the sensor element, and a package substrate that accommodates the sensor element and the plurality of lead portions. The plurality of lead portions are connected at proximal end sides thereof to the package substrate side, and connected at distal end sides thereof to the sensor element side, and the plurality of lead portions support the sensor element in such a manner that the sensor element does not contact the package substrate and that the transmission of deformation of the package substrate side to the sensor element is suppressed.
Abstract:
A method for fabricating packaged semiconductor devices (100) with an open cavity (110a) in panel format; placing (process 201) on an adhesive carrier tape a panel-sized grid of metallic pieces having a flat pad (230) and symmetrically placed vertical pillars (231); attaching (process 202) semiconductor chips (101) with sensor systems face-down onto the tape; laminating (process 203) and thinning (process 204) low CTE insulating material (234) to fill gaps between chips and grid; turning over (process 205) assembly to remove tape; plasma-cleaning assembly front side, sputtering and patterning (process 206) uniform metal layer across assembly and optionally plating (process 209) metal layer to form rerouting traces and extended contact pads for assembly; laminating (process 212) insulating stiffener across panel; opening (process 213) cavities in stiffener to access the sensor system; and singulating (process 214) packaged devices by cutting metallic pieces.