US Patent 7485489 Electronics circuit manufacture

A circuit with embedding components (13) is produced by placing the components (13) on a substrate (14) and applying sheets (15) of prepreg. The prepreg sheets (15) have apertures to accommodate the -components, the number of sheets and arrangement of apertures being chosen to accommodate a variety of component X, Y and Z dimensions. A top layer with Cu foil (16(b)) is applied. The assembly is pressed in an operation analogous to conventional multilayer board lamination pressing. This causes all of the prepreg resin to flow to completely embed the components without raids or damage. Electrical connections are made by drilling and plating vias.