Abstract: A magnetic device and a method of producing the same. In one embodiment, the device includes: (1) a substantially planar printed wiring board having a plurality of traces associated therewith, (2) a magnetic core located over the board, electrically insulated from the plurality of traces and having a major axis in parallel with a plane of the board and (3) a winding assembly having a dielectric member that couples a plurality of separate electrical conductors together, the plurality of conductors overarching the core to couple with corresponding ones of the plurality of traces to form a winding for the magnetic device, the dielectric member electrically insulating the plurality of conductors from the core.

Abstract: In accordance with the invention, a low profile magnetic device comprises a crelenated ferrite body having first and second conductive paths winding around the body. Current applied to one of the conductive windings can adjust the threshold current level in the other conductive winding at which the inductance characteristic changes to a relatively constant inductance.

Abstract: In accordance with the invention, a circuit module is provided with a plurality of dual capacity connector pads, each pad holding a miniature surface mount connector and/or a connection pin. The preferred I-channel surface mount connector is sufficiently small that the module can be connected by either surface mount or pin to the same region of the circuit board.

Abstract: In accordance with the invention, an I-channel surface mount connector comprising a length of cylindrical rod having a generally I-shaped cross section is improved by providing an extended mounting flange. When a first circuit device is connected to a second circuit device with the extended flange extending outward of the first device, the flange can extend beyond the periphery of the first device. This extension has the advantage that the solder bond between the flange and the second device can be easily inspected from above using visual inspection equipment.

Abstract: In accordance with the invention, a low impedance surface-mount connector comprises a length of cylindrical rod having an I-shaped cross section. The device permits interconnection by pick-and-place techniques, and the interconnection has advantageous qualities of low resistance, low inductance, mechanical compliance and ease of manufacture. A first circuit device having one or more circuit components is interconnected with a second circuit device by surface mounting such connectors on the first circuit device, providing corresponding solder pads on the second circuit device, and mounting the connectors of the first circuit device onto the pads of the second.

Abstract: In accordance with the invention, a semiconductor die having an input/output contact surface is interconnected with a substrate. A metal plate having a surface cavity is provided for receiving the die. The plate has peripheral surface regions surrounding the cavity. The die is mounted in the cavity with its contact surface co-planar with the peripheral regions, and a sealable contact region forming closed figure around the die is provided on the peripheral surface regions of the plate. A substrate surface is provided with a corresponding contact regions for receiving the die and the plate. The plate/die structure is mounted and solder bonded on the substrate. The resulting structure has reduced thermal impedance from the die/board surface through the plate and a continuous peripheral hermetic seal around the die.

Abstract: In accordance with the invention, a plurality of high thermal conductivity bodies are bonded to relatively hot spots of a component-populated substrate surface to provide thermal conduction from the surface to an overlying thermal plane. The high conductivity bodies can be configured for pick-and-place application and self-aligned in solder bonding. Receiving solder pads on the substrate facilitate low thermal resistance solder bonding and self-alignment. In a preferred embodiment the bodies are rectangular parallelpipeds with bifurcated bonding surfaces.

Abstract: An integral low profile inductive device includes a magnetic body having opposing face surfaces, opposing side surfaces extending between the face surfaces, and opposing end surfaces extending between the side surfaces. A recessed surface is defined in each of the side surfaces of the body. A continuous winding of conductive material extends across the recessed surfaces and face surfaces of the body. Each of the recessed surfaces can be crenelated with alternating secondary recesses and projections such that the winding passes over the secondary recesses as it extends across the side surfaces of the body or over the projections between the secondary recesses. The device can include one or more continuous windings each of at least one turn.

Abstract: A method for making a circuit device having at least one peripheral interconnect for electrically connecting the device to another circuit device on a motherboard, includes forming at least one opening in a substrate, the opening having an inner surface extending between first and second major surfaces of the substrate. The inner surface of the opening and portions of the major surfaces adjacent the opening are coated with electrically conductive material. Electrically conductive material is removed from opposing regions of the inner surface of the opening prior to plating and then, after plating, the substrate is cut in a line extending across opposing regions to expose the coated and plated inner surface as the peripheral electrical interconnect. The method produces interconnects with reduced contamination by conductive particulates.

Abstract: A subscriber line circuit which truly implements all of the BORSCHT functions and which does not rely on an external ringing generator to provide the ringing voltage when needed is disclosed. This implementation is achieved by recognizing that supervisory and ringing signals occur in some sort of sequence and, therefore, do not have to be generated simultaneously. Based on this recognition, we provide a circuit which truly implements all of the BORSCHT functions and includes a power section that generates each of the supervisory signals, e.g., -48 volts and -24 volts, and alerting signal, e.g., ringing signal, in turn and as required.

Abstract: The method of making a metallized magnetic substrate for devices including a magnetic component involves providing an unfired ceramic body. In one exemplary embodiment, the method further involves making one or more vias through the ceramic body, coating the via side walls with conductive material, forming an aperture through the ceramic body, such that an aperture edge intersects the via, and metallizing the unfired ceramic body such that a conductive pathway is formed that includes the conductive material in the via. Finally, the metallized unfired ceramic body is fired in conventional fashion, optionally followed by deposition of additional conductor material.

Abstract: For use in a battery reserve system having a reserve battery, a charging circuit coupled between a source of electrical power and the reserve battery for charging the reserve battery and a heating element in thermal communication with the reserve battery for increasing a temperature of the battery, a mode selection circuit and method of operation thereof. The mode selection circuit includes: (1) a temperature transducer, coupled to the reserve battery, for sensing the temperature of the reserve battery and (2) a mode-changing circuit, coupled to the temperature transducer, for selecting an alternative one of: (a) a heating mode wherein the source of electrical power is coupled to the heating element when the temperature of the reserve battery is less than a reference temperature thereby to heat the reserve battery and (b) a charging mode wherein the source of electrical power is coupled to the reserve battery when the temperature is greater than the reference temperature thereby to charge the reserve battery.

Abstract: The thickness uniformity of a plated metal layer inside a via hole can be enhanced by intersecting a conductive via with an insulating aperture before plating. The new via configuration improves the mass transfer of the plating. It is believed that the apertures lower the local solution ohmic resistance near the via holes. The method can be applied to the manufacture of a wide variety of circuit boards.

Abstract: In accordance with the invention, a low inductance surface-mount connector comprises a slotted, hollow rectangular parallelepiped. The device permits interconnection by pick-and-place techniques, and the interconnection has advantageous qualities of compactness, low inductance, and mechanical compliance. A first circuit device having one or more circuit components is interconnected with a second circuit device by surface mounting such connectors on the first circuit device, providing corresponding solder pads on the second circuit device, and mounting the connectors of the first circuit device onto the pads of the second.

Abstract: In accordance with the invention, a variety of magnetic devices can be made up of two or more low-profile surface components on a printed circuit board. For example, low profile devices comparable to gapped U-core pair and gapped E-core pair inductors or transformers can be formed of two and three components, respectively, and four components can be assembled into a gapped toroidal transformer or inductor. The components can be made in form for both linear and non-linear inductors.

Abstract: Magnetic components are fabricated as monolithic structures using multilayer co-fired ceramic tape techniques. Fabrication of these magnetic components involves constructing multiple layers of a magnetic material and an insulating non-magnetic material to form a monolithic structure with well defined magnetic and insulating non-magnetic regions. Windings are formed using screen printed conductors connected through the multilayer structure by conducting vias.

Abstract: The present inventors have discovered that a compact, highly sensitive current sensor can be made for any inductive component having an air gap in its magnetic path by disposing a layer of magnetoresistive material in the path of the fringing magnetic field. In the preferred embodiment, a thin magnetoresistive film of La.sub.w Ca.sub.x Mn.sub.y O.sub.z on a LaAlO.sub.3 /Al.sub.2 O.sub.3 substrate provides a high sensitivity in the range of 1-100 mV/ampere of DC current in the inductive component. The current sensor consumes a very small amount of power and provides the desirable electrical isolation between the sensor and the active device circuit.

Abstract: Magnetic components are fabricated as monolithic structures using multilayer co-fired ceramic tape techniques. Fabrication of these magnetic components involves constructing multiple layers of a magnetic material and an insulating non-magnetic mataerial to form a monolithic structure with well defined magnetic and insulating non-magnetic regions. Windings are formed using screen printed conductors connected through the multilayer structure by conducting vias.

Abstract: Multilayer magnetic components can be made with reduced cracking and magnetic degradation by forming layers having patterns of magnetic and insulating regions separated by regions that are removable during sintering. Advantageously, when the layers are stacked, layers of removable material are also disposed between magnetic regions and insulating regions so as to produce upon sintering a magnetic core within an insulating body wherein the core is substantially completely surrounded by a thin layer of free space.

Abstract: A superconducting switching device having no moving components for reversing current flow through a load. This load typically is a superconducting magnet and, in this application, the present invention also selectively serves as a persistent switch. The invention includes a pair of switching units connected between the load (magnet) and a current source. These switching units each have a pair of superconductor members and a mechanism for selectively producing in the switching units either a substantial electrical resistance or no resistance. Through the use of a control logic, the level of resistance of the switching units can be changed to effect the direction of current flow. In the case of the superconductor magnet, both switch units can be simultaneously made to have substantially zero resistance, and their interconnection forms the persistent switch for the superconducting magnet.