Patent ID: 7371976

Claim:
A multilayer printed circuit board comprising: a first insulating layer; a first conductor circuit formed on the first insulating layer; an outermost insulating layer formed over the first insulating layer; an outermost conductor circuit formed on the outermost insulating layer; at least one viahole structure electrically connecting the first conductor circuit and the outermost conductor circuit, the viahole structure having a conductor portion; and a solder resist layer formed on the outermost insulating layer and the outermost conductor circuit, the solder resist layer having at least one opening portion formed therein; wherein the opening portion of the solder resist layer partially exposes the conductor portion of the viahole structure to form a pad portion configured to mount a semiconductor element, the viahole structure and the outermost conductor circuit comprise an electroless plated film and an electrolytic plated film formed on the electroless plated film, and the outermost conductor circuit has an upper surface and side surfaces, the side surface being at least partially roughened.