Multilayer printed circuit board includes a core substrate and multilayer
wiring layers formed on the core substrate by alternately laminating
interlaminar insulating layer and conductor circuit. The multilayer
printed circuit board further includes a group of solder pads having
solder bumps planarly arranged on an outermost surface of the multilayer
wiring layers. Solder pads located in at least one and up to five rows
from an outer position of the solder pad group have flat pads connected to
a conductor pattern located on the outermost surface and have solder bumps
formed on surfaces of the solder pads, while solder pads other than the
solder pads connected to the conductor pattern on the outermost surface
form an inner layer pad group. Solder pads of the inner layer pad group
are connected to viaholes connected to flat inner layer pads located on
one of a first inner layer and at least one further inner layer with
solder bumps being formed in recess portions of the viaholes, the inner
layer pad group comprising solder pads located in at least one and up to
five rows from an outer position of the inner layer pad group that are
connected through the viaholes to flat pads connected to conductor
patterns on the first inner layer, while solder pads of the inner layer
pad group other than the solder pads connected to flat pads connected to
conductor patterns on the first inner layer are connected through the
viaholes to flat pads located on the at least one further inner layer
located inward relative to the first inner layer.
