Abstract: A method and system for determining properties of a fluid involves interacting the fluid with a standing wave in a first state to establish the standing wave in a second state, analyzing an electric signal associated with the standing wave to determine a characteristic associated with the second state, and determining the property of the fluid by comparing the characteristic with a function that associates a plurality of properties with a corresponding plurality of characteristics. The characteristic can include a maximum phase slope, a phase slope associated with a resonant frequency, a maximum magnitude associated with the resonant frequency, the value of the resonant frequency, or any combination thereof.

Abstract: A microelectronic spring contact for making electrical contact between a device and a mating substrate and method of making the same are disclosed. The spring contact has a compliant pad adhered to a substrate of the device and spaced apart from a terminal of the device. The compliant pad has a base adhered to the substrate, and side surfaces extending away from the substrate and tapering to a smaller end area distal from the substrate. A trace extends from the terminal of the device over the compliant pad to its end area. At least a portion of the compliant pad end area is covered by the trace, and a portion of the trace that is over the compliant pad is supported by the compliant pad. A horizontal microelectronic spring contact and method of making the same are also disclosed. The horizontal spring contact has a rigid trace attached at a first end to a terminal of a substrate.

Abstract: A microelectronic spring contact for making electrical contact between a device and a mating substrate and method of making the same are disclosed. The spring contact has a compliant pad adhered to a substrate of the device and spaced apart from a terminal of the device. The compliant pad has a base adhered to the substrate, and side surfaces extending away from the substrate and tapering to a smaller end area distal from the substrate. A trace extends from the terminal of the device in a coil pattern over the compliant pad to its end area, forming a helix. At least a portion of the compliant pad end area is covered by the trace, and a portion of the trace that is over the compliant pad is supported by the compliant pad. In an alternative embodiment, the pad is removed to leave a freestanding helical contact.

Abstract: A method for fabricating microelectronic spring structures is disclosed. In an initial step of the method, a layer of sacrificial material is formed over a substrate. Then, a contoured surface is developed in the sacrificial material, such as by molding the sacrificial material using a mold or stamp. The contoured surface provides a mold for at least one spring form, and preferably for an array of spring forms. If necessary, the sacrificial layer is then cured or hardened. A layer of spring material is deposited over the contoured surface of the sacrificial material, in a pattern to define at least one spring form, and preferably an array of spring forms. The sacrificial material is then at least partially removed from beneath the spring form to reveal at least one freestanding spring structure. A separate conducting tip is optionally attached to each resulting spring structure, and each structure is optionally plated or covered with an additional layer or layers of material, as desired.

Abstract: An electronic component is disclosed, having a plurality of microelectronic spring contacts mounted to a planar face of the component. Each of the microelectronic spring contacts has a contoured beam, which may be formed of an integral layer of resilient material deposited over a contoured sacrificial substrate, and comprises a base mounted to the planar face of the component, a beam connected to the base at a first end of the beam, and a tip positioned at a free end of the beam opposite to the base. The beam has an unsupported span between its free end and its base. The microelectronic spring contacts are advantageously formed by depositing a resilient material over a molded, sacrificial substrate. The spring contacts may be provided with various innovative contoured shapes. In various embodiments of the invention, the electronic component comprises a semiconductor die, a semiconductor wafer, a LGA socket, an interposer, or a test head assembly.

Abstract: A forming tool with one or more embossing tooth, and preferably, a plurality of such embossing teeth, arranged on a substantially planar substrate, is disclosed. Each embossing tooth is configured for forming a sacrificial layer to provide a contoured surface for forming a microelectronic spring structure. Each embossing tooth has a protruding area corresponding to a base of a microelectronic spring, and a sloped portion corresponding to a beam contour of a microelectronic spring. Numerous methods for making a forming tool are also disclosed. The methods include a material removal method, a molding method, a repetitive-stamping method, tang-bending methods, and segment-assembly methods.

Abstract: A position sensor for measuring the distance from a first position to a second position. The sensor may include an elastic wave generator, an acoustical path over which the elastic wave passes, and a transducer to which the wave passes. A measurement loop includes the acoustical path, and has electrical and optical elements. The electrical elements may compare the phases of the transducer signals from which the change in position between the first and second positions are determined. Alternatively, the measurement loop may comprise a feedback loop to produce oscillations and an output frequency. A frequency counter is included in the feedback loop to measure frequency.

Abstract: A position sensor for measuring the distance from a first position to a second position. The sensor may include an elastic wave generator, an acoustical path over which the elastic wave passes, and a transducer to which the wave passes. A measurement loop includes the acoustical path, and has electrical and optical elements. The electrical elements may compare the phases of the transducer signals from which the change in position between the first and second positions are determined. Alternatively, the measurement loop may comprise a feedback loop to produce oscillations and an output frequency. A frequency counter is included in the feedback loop to measure frequency.