초록 ▼

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 positione

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.

대표청구항 ▼

A method of fabrication of circuit boards, comprising the steps of: impregnating a woven graphite cloth with a resin to form a plurality of solid graphite sheets; etching a plurality of copper-clad sheets of polytetrafluoroethylene (PTFE) and woven glass with predefined circuit patterns; and laminat

A method of fabrication of circuit boards, comprising the steps of: impregnating a woven graphite cloth with a resin to form a plurality of solid graphite sheets; etching a plurality of copper-clad sheets of polytetrafluoroethylene (PTFE) and woven glass with predefined circuit patterns; and laminating the graphite sheets and the copper-clad sheets, together with other sheets of PTFE and woven glass, to form a composite printed circuit board; wherein at least some of the graphite sheets are positioned in close proximity to some of the copper-clad sheets to provide a low resistance path for the flow of heat from the copper circuit patterns; and wherein the graphite sheets are positioned in a symmetrical manner with respect to the thickness of the composite board and selected in number to provide a desired composite coefficient of thermal expansion.