Patent ID: 7448126

Claim:
A subassembly manufactured by a process comprising the steps of: manufacturing a plurality of composite substrate layers; manufacturing a flange layer comprising a substantially homogeneous metal core; drilling through said composite substrate layers to create a plurality of vias; forming a cutout in each of the plurality of composite substrate layers such that when the composite substrate layers are positioned in a stacked arrangement on top of the flange layer said cutouts form a cavity through the substrate layers that exposes a top surface of the flange layer; selectively metalicizing surfaces of said composite substrate layers to form embedded signal processing circuitry elements, a signal input terminal, a signal output terminal, a first and a second signal connection terminal exposed within said formed cavity, and conductive vias interconnecting said embedded signal processing circuitry elements, signal input terminal, signal output terminal, first and second signal connection terminal when the plurality of composite substrate layers are positioned in stacked arrangement; fusion bonding said plurality of substrate layers to each other and to the flange layer such that the plurality of substrate layers are positioned in a stacked arrangement on top of the flange layer and form an assembly having a cavity through an area of the plurality of substrate layers whereby: said cavity exposes a top surface of the flange layer and exposes signal connection terminals coupled to the embedded signal processing circuitry, and said cavity enables the addition of a circuit element to the assembly after the fusion bonding of the substrate layers and enables coupling of the added circuit element to the signal processing circuitry and to the flange layer.