High-frequency multilayer printed circuit board
AssigneeTRW Inc.
InventorJoseph D. Leibowitz
Life of this patent
Estimating the term…
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.
Claims18
A high-frequency multilayer printed circuit, comprising:
- a plurality of layers of a conductive metal;
- a plurality of layers of graphite, at least some of which are positioned in close proximity to some of the layers of conductive metal to provide a relatively low resistance path for the flow of heat from the layers of conductive metal;
- and
- a plurality of layers of a dielectric material;
- wherein the layers are bonded together to form a composite multilayer printed circuit board, the layers of graphite being positioned in a symmetrical manner with respect to the thickness of the circuit board and selected in number to provide a multilayer circuit board having a desired coefficient of thermal expansion;
- and wherein some of the layers of conductive metal are appropriately patterned and combined with other layers of conductive metal and layers of dielectric material to form one or more strip or microstrip transmission lines for electrically connecting very high frequency electronic components mounted on the board.
A high-frequency multilayer printed circuit board, comprising:
- a plurality of metal-clad layers of a dielectric material, each layer having both sides plated with a conductive metal layer;
- plurality of layers of graphite, some of which are metal-clad layers of graphite having one side plated with a conductive metal layer;
- and
- plurality of unclad layers of a dielectric material;
- wherein the layers are bonded together to form a composite multilayer printed circuit board, the layers of graphite being positioned in a symmetrical manner with respect to the thickness or the circuit board and selected in number to provide a multilayer circuit board having a desired coefficient of thermal expansion;
- and wherein some of the metal-clad layers of dielectric material are appropriately patterned to form microstrip transmission lines for electrically connecting very high frequency electronic components mounted on the board, the patterned conductive metal layers forming the line conductors of the microstrip transmission lines and the unpatterned conductive metal layers forming the ground planes.
A method for fabricating a multilayer printed circuit board, comprising the steps of:
- forming a plurality of solid graphite sheets;
- plating one side of some of the solid graphite sheets with a metal conductive layer;
- plating both sides of a plurality of sheets of a dielectric material with a metal conductive layer to form metal-clad sheets of dielectric material;
- etching one side of some of the metal-clad sheets of dielectric material with predefined circuit patterns;
- and
- laminating the graphite sheets and the metal-clad sheets of dielectric material, together with unclad sheets of a dielectric material, to form a composite printed circuit board;
- wherein the graphite sheets are positioned in a symmetrical manner with respect to the thickness of the circuit board and selected in number to provide a multilayer circuit board having a desired coefficient of thermal expansion;
- and wherein some of the patterned metal-clad sheets of dielectric material form microstrip transmission lines for electrically connecting very high frequency electronic components mounted on the board, the patterned conductive metal layers forming the line conductors of the microstrip transmission lines and the unpatterned conductive metal layers forming the ground planes.
Dependencies are inferred from the claim text.