Circuit-on-foil process for manufacturing a laminated semiconductor package substrate having embedded conductive patterns

摘要

A circuit-on-foil process for manufacturing a laminated semiconductor package substrate having embedded conductive patterns provides a high-density mounting and interconnect structure for semiconductor packages that is manufacturable in volume. A dielectric film is laminated on one or both sides with a foil layer with a circuit pattern disposed on a surface of the foil. The circuit-on-foil layer can be made by laser-ablating a plating resist material and then plating metal atop a foil, or by laser-exposing a photo-sensitive plating resist material and then plating the circuit pattern atop the foil. After lamination, the metal foil is removed by etching or machining to leave only the dielectric and embedded conductors. Vias can be formed between layers of embedded conductors by laser-drilling holes either though the entire substrate or from one side through to at least the bottom of one of the embedded circuit layers, and then filling the hole with metal.