A package substrate of, for example, a BGA type or a CSP type, manufactured by
carrying out an electrolytic Au plating process without using any plating lead
line for formation of bond fingers and solder ball pads, and a method for manufacturing
the package substrate. The method includes the steps of laminating first dry films
over upper and lower surfaces of a base substrate having via holes while being
formed at its upper and lower surfaces with copper foils, and patterning the first
dry films to expose predetermined surface portions of the base substrate, removing
portions of the copper foils not covered by the first dry films to form circuits,
stripping the first dry films, and forming a plated layer over the base substrate,
laminating second dry films over the plated surfaces of the base substrate, and
patterning the second dry films to expose portions of the plated surfaces of the
base substrate corresponding to regions where Au is to be plated, removing the
plated layer from the exposed surface portions of the base substrate corresponding
to the Au plating regions, plating Au on the exposed surface portions of the base
substrate, stripping the second dry films, and removing the remaining plated layer
to expose the circuits, and coating a solder resist on the exposed circuits while
exposing predetermined portions of the circuits.