Abstract: An integrated circuit package includes a substrate having a circuitry pattern formed on the substrate. A thermoplastic attachment film is positioned on the substrate and has vias that expose the circuitry pattern. A flip chip has input/output contacts formed as conductive bumps and mounted on the thermoplastic attachment film such that the conductive bumps are received within the cut openings and engage the circuitry pattern. The thermoplastic attachment film forms an underfill and a thermoplastic bond between the substrate and the flip chip, which allows ready removal of the flip chip upon application of heat. A method is also disclosed forming the integrated circuit package using the flip chip, thermoplastic attachment film and substrate of the present invention.

Abstract: An integrated circuit package includes a substrate having a circuitry pattern formed on the substrate. A thermoplastic attachment film is positioned on the substrate and has vias that expose the circuitry pattern. A flip chip has input/output contacts formed as conductive bumps and mounted on the thermoplastic attachment film such that the conductive bumps are received within the cut openings and engage the circuitry pattern. The thermoplastic attachment film forms an underfill and a thermoplastic bond between the substrate and the flip chip, which allows ready removal of the flip chip upon application of heat. A method is also disclosed forming the integrated circuit package using the flip chip, thermoplastic attachment film and substrate of the present invention.

Abstract: A monolithic FET bridge attenuator contains four single gate FETs, the source-drain path of each of which forms a respective arm of the bridge. The attenuation control electrodes (gates) of the FETs in opposite arms of the bridge are connected to a common control voltage. A first pair of diagonally opposing nodes of the bridge are coupled to receive respective input signals that differ in phase by 180.degree.. A second pair of diagonally opposing nodes of the bridge disposed between the first pair of nodes provide a pair of output signals differing in phase by 180.degree.. In effect, each FET has the electrical behavior of a parallel RC circuit, the resistive component of which is controlled by the gate voltage.

Abstract: A dual gate MESFET attenuator circuit provides substantial range of attenuation without phase shift through a cascaded arrangement of a pair of dual gate MESFETs and the incorporation of a feed forward resistor. By cascading the two transistors together, the attenuation vector characteristics are effectively rotated 180.degree. or shifted to the third and fourth quadrants of the (real/imaginary) vector plane. The resulting phase shift between the minimum attenuation vector and the maximum attenuation vector is compensated by the insertion of a pure resistance component in a feed forward fashion between the input and output terminals of the cascaded dual MESFET pair. The value of the inserted resistor is chosen so as to effectively make both the maximum attenuation vector and the minimum attenuation vector cophasal, thereby providing a constant phase shift through the attenuator over a substantial range of attenuation.

Abstract: A microwave transistor circuit includes a pair of field effect transistors connected in cascade via a standard 50 ohm transmission line having a length equal to one-half the wavelength of the operating frequency range of the circuit. Although the field effect transistors are individually unstable at microwave frequencies, by cascading these transistors the reverse transmission coefficient is sufficiently reduced to render the overall circuit unconditionally stable. In addition, the transmission line is opened to provide physical isolation between the transistors for d.c. bias isolation and a capacitor is connected therein to provide for RF continuity.