Patent ID: 7065869

Claim:
A method of making a plurality of printed circuit board units (PCB units), comprising: forming a PCB strip having a solder side, a component side, and an inner layers disposed between said solder and said component side; forming a first circuitry pattern on said component side, said first circuit pattern being formed of first copper clad parts, first solder ball parts and first via conductive lands; forming a second circuitry pattern on said solder side, said second circuit pattern being formed of second copper clad parts, second solder ball parts and second via conductive lands; forming a third circuitry pattern on said inner layer, said third circuit pattern being formed of third copper clad parts, third solder ball parts and third via conductive lands, wherein said inner layer having through holes connected to the third via conductive lands and a sub-plating line connected to the third copper clad parts, said first, second and third patterns defining on said PCB strip a plurality of PCB units; wherein, said first copper-clad parts of said first circuit pattern being shaped and constructed to receive a plurality of components, each PCB unit having at least one component mounted thereon; said third copper-clad parts being formed with said via conductive lands being disposed around said through holes; wherein only one of said first, second and third circuit patterns includes a main plating line separating the PCB units; and cutting said PCB strip along said main plating line to separate said PCB units.