67results about How to "Well matched thermal expansion" patented technology

A MEMS microphone system suited for harsh environments. The system uses an integrated circuit package. A first, solid metal lid covers one face of a ceramic package base that includes a cavity, forming an acoustic chamber. The base includes an aperture through the opposing face of the base for receiving audio signals into the chamber. A MEMS microphone is attached within the chamber about the aperture. A filter covers the aperture opening in the opposing face of the base to prevent contaminants from entering the acoustic chamber. A second metal lid encloses the opposing face of the base and may attach the filter to this face of the base. The lids are electrically connected with vias forming a radio frequency interference shield. The ceramic base material is thermally matched to the silicon microphone material to allow operation over an extended temperature range.

The invention relates to a preparation process of a carbon fiber concave reflector, which belongs to the technical field of optical element preparation. The invention solves the problems of high manufacturing process cost of the carbon fiber concave reflector, difficult mold processing and the like in the prior art. In the preparation process of the present invention, optical glass is firstly used as a material to prepare a concave reflector mold having the same structure as the carbon fiber concave reflector to be prepared, and then a release agent is applied on the concave reflector mold and multiple layers are spread on the release agent. layer of carbon fiber prepreg, solidify and mold the laid carbon fiber prepreg, and demould to obtain a convex carbon fiber mirror mold, and then apply a release agent on the convex carbon fiber mirror mold and lay multiple layers of carbon fiber prepreg on the release agent. Soak the cloth, solidify and mold the laid carbon fiber prepreg cloth, and demould to obtain a concave carbon fiber reflector blank; finally, carry out surface treatment on the concave carbon fiber reflector blank to obtain a carbon fiber concave reflector. The preparation process is simple and easy, the cost is low, and the prepared reflection mirror has high precision.

A method of fabricating suspended beam silicon carbide microelectromechanical (MEMS) structure with low capacitance and good thermal expansion match. A suspended material structure is attached to an anchor material structure that is direct wafer bonded to a substrate. The anchor material structure and the suspended material structure are formed from either a hexagonal single-crystal SiC material, and the anchor material structure is bonded to the substrate while the suspended material structure does not have to be attached to the substrate. The substrate may be a semi-insulating or insulating SiC substrate. The substrate may have an etched recess region on the substrate first surface to facilitate the formation of the movable suspended material structures. The substrate may have patterned electrical electrodes on the substrate first surface, within recesses etched into the substrate.