Abstract: In accordance with the present invention, a circuit assembly is manufactured in an additive process using at least one layer of a fluoropolymer composite material and a conductive material. The conductive layers are plated, and the fluoropolymer composite layers are laminated. The use of the filled fluoropolymeric composite eliminates the need for a barrier metal layer between the insulation and the conductors. A plurality of these circuit assemblies are stacked, one on top of the other. At least, selected exposed locations of the conductive material comprise a diffusible conductive material (e.g., gold). Once stacked the circuit assemblies are subjected to lamination under heat and pressure to simultaneously fuse adjacent fluoropolymer composite material and diffuse adjacent diffusible conductive material together to form an integral multilayer circuit having solid conductive interconnects.

Abstract: In accordance with the present invention, an MCM substrate product is manufactured in an additive process using multiple layers of a fluoropolymer composite material and copper. The copper layers are plated, and the fluoropolymer composite layers are laminated. A seeding process promotes reliable bonding between the fluoropolymer composite material and the plated copper. The use of the filled fluoropolymeric composite eliminates the need for a barrier metal layer between the insulation and the conductors. The MCM substrate device of the present invention may have multiple metal layers and multiple dielectric layers; four or five, or more, of each in a single structure would be easily achieved and is typical. The structure would include lead lines in separate mutually orthogonal planes (sometimes referred to as "x" and "y" lead lines) sandwiched between ground and power voltage planes of copper.