Abstract: An improved electrical junction box includes a housing, a multilayer printed circuit board supported by the interior of the housing and an array of electrical connectors supported by the exterior of the housing. The electrical connectors make electrical contact with one or more circuit traces in the multilayer circuit board. The circuit traces are of varying thicknesses according to the current levels to be conducted by the traces, thus minimizing the amount of copper required to fabricate the junction box. The circuit traces with the greater thicknesses are positioned in the outer layers of the circuit board to enhance heat dissipation from the circuit board.

Abstract: A multilayer printed circuit board in which multiple layers of a composite material, fabricated by the lay-up of an aramid fiber tape, are employed to provide a circuit board with a desired coefficient of thermal expansion. Tape lay-up of aramid fibers provides a composite layer having a lower thermal coefficient of expansion than a composite layer fabricated from woven aramid fibers. Degradation in the tensile modulus of elasticity caused by the over and under characteristics of woven fabrics is also eliminated by tape lay-up, thus providing a circuit board with better mechanical strength. In addition, tape lay-up reduces the amount of resin required to fabricate the circuit board and eliminates the need for twisting the aramid fibers into yarns and then weaving the yarns, thus reducing the cost of the circuit board.

Abstract: A multilayer printed circuit board in which multiple layers of a composite material, fabricated by the lay-up of an aramid fiber tape, are employed to provide a circuit board with a desired coefficient of thermal expansion. Tape lay-up of aramid fibers provides a composite layer having a lower thermal coefficient of expansion than a composite layer fabricated from woven aramid fibers. Degradation in the tensile modulus of elasticity caused by the over and under characteristics of woven fabrics is also eliminated by tape lay-up, thus providing a circuit board with better mechanical strength. In addition, tape lay-up reduces the amount of resin required to fabricate the circuit board and eliminates the need for twisting the aramid fibers into yarns and then weaving the yarns, thus reducing the cost of the circuit board.

Abstract: A circuit board having multiple layers of a dielectric material, multiple layers of a conductive metal and multiple layers of graphite bonded together to form a composite multilayer printed circuit board having a desired coefficient of expansion and having strip and microstrip transmission lines for electrically connecting very high frequency electronic components mounted on the circuit board. The multiple layers of graphite are positioned in a symmetrical manner with respect to the thickness of the circuit board and selected in number to provide the circuit board with a desired coefficient of expansion. In addition, at least some of the layers of graphite are positioned in close proximity to some of the layers of conductive metal to provide enhanced thermal conduction from the mounted components.

Abstract: A composite printed circuit board structure including multiple layers of graphite interleaved with layers of a dielectric material, such as a polytetrafluoroethylene (PTFE) and woven glass laminate. Some of the dielectric layers are copper clad, and at least some of the graphite layers are positioned in close proximity to the copper cladding layers, to provide good heat dissipation properties. The PTFE provides a desirably low dielectric constant and the graphite also provides good mechanical strength and a low or negative coefficient of thermal expansion, to permit matching of the coefficient with that of chip carriers used to mount components on the circuit board.

Abstract: A composite printed circuit board structure including multiple layers of graphite interleaved with layers of a dielectric material, such as a polytetrafluoroethylene (PTFE) and woven glass laminate. Some of the dielectric layers are copper clad, and at least some of the graphite layers are positioned in close proximity to the copper cladding layers, to provide good heat dissipation properties. The PTFE provides a desirably low dielectric constant and the graphite also provides good mechanical strength and a low or negative coefficient of thermal expansion, to permit matching of the coefficient with that of chip carriers used to mount components on the circuit board.

Abstract: A composite characterized by a controlled coefficient of thermal expansion and comprising a thermal coefficient control fabric embedded in a resin matrix and composed of yarns with positive and negative coefficients of thermal expansion. A composite circuit board constructed of the composite and having a coefficient of thermal expansion matched to a particular integrated chip carrier material, such as aluminum oxide.