Abstract:
The invention provides a high density package substrate and a method for fabricating the same. A double-sided copper clad laminate containing an upper copper foil and a lower copper foil is provided. A bottom pad is disposed on the lower copper foil, aligned to a predetermined position of a through hole. The through hole is formed by laser drilling through the upper copper foil and the substrate, but not through the bottom pad. A seed layer is formed conformally lining the through hole, and a metal layer is formed on the seed layer by plating to form a plated through hole (PTH).
Abstract:
The invention provides a high density package substrate and a method for fabricating the same. A double-sided copper clad laminate containing an upper copper foil and a lower copper foil is provided. A bottom pad is disposed on the lower copper foil, aligned to a predetermined position of a through hole. The through hole is formed by laser drilling through the upper copper foil and the substrate, but not through the bottom pad. A seed layer is formed conformally lining the through hole, and a metal layer is formed on the seed layer by plating to form a plated through hole (PTH).