Patent ID: 7535095

Claim:
A multilayer printed circuit board comprising: a resin substrate having a first surface and a second surface; a first resin insulating layer formed over at least one of the first and second surfaces of the resin substrate, the first resin insulating layer comprising a thermosetting polyolefin resin; a lower metal layer formed on the first resin insulating layer; and a conductor circuit comprising a metal and formed on the lower metal layer, wherein said lower metal layer has a same pattern as said conductor circuit and comprises at least one metal selected from the group consisting of metals of the 4th through 7th periods in Group 4A through Group 1B of the long-form periodic table of the elements, Al, and Sn, excluding Cu, and said first resin insulating layer has a flat and level surface such that the lower metal layer formed on said flat and level surface of said first resin insulating layer is made sufficiently flat and level and said conductor circuit formed on said lower metal layer is made sufficiently flat to provide no signal conduction delay for a high frequency signal.