摘要:
A sensor that is responsive to at least two distinct spectral bands, e.g., infrared radiation and ultraviolet or infrared and visible light makes use of the junction of a diode-based bolometer as a photocell in addition to its temperature dependence for detecting infrared radiation. More specifically the diode bolometer is arranged to work in the conventional manner, in that an electrical characteristic of the diode, e.g., the temperature dependence of its current-voltage (I-V) curve, is used as the basis for measuring temperature, and hence, infrared radiation. Additionally, the same diode may be operated as a photocell to detect radiation that is capable of interacting with the electrons in the junction of the diode. This may be achieved by detecting a change in the operating point of the diode based given its present biasing in response to noninfrared radiation incident upon the diode.
摘要:
A highly reliable fuse for explosives and armaments is achieved by employing a micro mechanical device that operates to disrupt a relatively low impedance bypass circuit coupled in parallel with a relatively high impedance trigger mechanism. The removal of the electrical bypassing is performed as a result of the movement of the micro mechanical device to enable detonation under prescribed conditions. The electrical bypassing is removed by having at least one low impedance electrical bridge that is part of the bypass circuit break when the micro mechanical device is subjected to prescribed trigger activation forces, which are typically large forces, such as are generated during launch or impact. The micro mechanical device may be a micro-electrical mechanical system (MEMS) device and the bridge is at least one spring that is part of the MEMS device and also part of the bypass circuit.
摘要:
An arbitrary gap between the two chips of a MEMS device arranged in a flip-chip arrangement is achieved by etching into a first substrate to form mesas which act as spacers between which, or even on which, any required circuit elements are formed. Points of a layer at a first surface of the second substrate within which MEMS structures are made are bonded to the mesas of the first substrate. The second substrate is then removed, leaving the structures bonded to the mesas. The mesas may be formed by placing a hard mask, such as silicon oxide, which defines the desired pattern of mesas on the first substrate, and then etching the unmasked portion of the substrate using a mixture of potassium hydroxide (KOH) with isopropanol (IPA) or, tetramethyl ammonium hydroxide (TMAH) mixed with a surfactant, e.g., nonylphenol ethoxy ether or other equivalent compounds.
摘要:
A precise fiber array is formed using a chuck to tightly hold as an array with hexagonal packing a group of precision ferrules into ones of which is inserted and bonded a fiber end. The bonding is typically performed by gluing the fiber into the ferrule. The ferrules may also be bonded to each other. Once the ferrules are bonded together, the chuck may be removed. The terminating end of the fibers may be polished. Alternatively, cleaved terminating fiber ends may be employed, with the various terminating ends being coordinated, e.g., by an optical flat. The ferrules may have a tip and a conical entrance. The chuck may hold the ferrules in a straight orientation. The fiber terminating faces of all of the ferrules may be substantially coplanar. The ferrules may be arranged in a hexagonal configuration.
摘要:
Problems caused by a nonuniform processing profile are avoided by altering the area to be processed so as to compensate for the processing profile. More specifically, with regard to etching, problems caused by a nonuniform etch profile can be avoided by altering the mask employed in specifying the etch area so as to compensate for the etch profile. Nonuniform parameters of interest of structures which result from a nonuniform etch profile during the etching of a mask in which all the structures were identical can be avoided for by altering the mask employed in specifying the etch area so as to compensate for the etch profile. The mask is changed in a manner that is inversely proportional to the etch profile for each particular structure characteristic that determines the parameter of interest for which uniformity is desired.
摘要:
A mechanical switch includes a pair of conducting contacts, metal located on and between the conducting contacts, a heater, and an electro-mechanical actuator. The heater is operable to apply heat that melts the metal. The electro-mechanical actuator is capable of moving one or both of the conducting contacts in a manner that causes the metal to either start physically bridging the conducting contacts or to stop physically bridging the conducting contacts.
摘要:
A precise array of collimated light beams may be obtained by employing a chuck to tightly hold as an array a group of precision collimators attached to individual optical fibers. Advantageously, such arrays of collimators may be manufactured to very high tolerances so as to be useful in positioning collimated light beams for all-optical switching.
摘要:
A precise fiber array may be formed by employing an array of pins into ones of the resulting interstices of which is inserted and bonded, e.g., glued, a fiber end. Such an array may be made by employing a chuck, at least initially, to tightly hold as an array a group of pins, e.g., metal, ceramic, or plastic pins. Thereafter, a fiber end is inserted and bonded into ones of the interstices formed by the resulting gaps, i.e., the interstices, between the pins. The pins may also be bonded to each other. If so, once the pins are bonded together, the chuck may be removed. The terminating end of the fibers may be polished. Alternatively, previously cleaved terminating fiber ends may be employed, with the various terminating ends being coordinated, e.g., by an optical flat or other surface which is placed at, or adjacent to, the fiber terminating end of the pin array.
摘要:
A thermal management for EMI shielded circuit packs having one or more high-power components, i.e. heat sources. More particularly, a heat transfer device or assembly for EMI shielded circuit packs is provided whereby multiple components (e.g., high-power components) are cooled by individual heat sinks (i.e., each component has its own individual heat sink) which protrude into an external airflow through individual openings in the lid of the EMI shield. Mechanically-compliant, electrically-conductive gaskets are used to seal the base plates of the individual heat sinks against the lid of the EMI shield enclosure. As such, in accordance with the various embodiments, the conductive gaskets establish a compliance layer which accommodates any variation in the heights of the individual components, thereby, allowing optimum thermal contact between the components and their respective heat sinks without compromising the EMI shielding.
摘要:
A micro lens, or an array of micro lenses, can be formed without requiring the etching of a mesa into the substrate by deposited directly on the substrate, without any mesa each of the individual portions of the substance to be melted. The whole substrate and the portions are then conformally coated with a very thin layer of a substance, typically an adhesion promoter, e.g., hexamethyldisilazane (HMDS). The entire coated wafer is then subject to conditions which cause each of the individual substance portions to flow into a lens shape. A lens shape is achieved without requiring a mesa because the layer of adhesion promoter prevents the flowing substance from spilling in an undesired manner over the surface of the substrate.