A multilayer circuit board having a high level of reliability in terms of
electric connection against temperature changes caused by the actual
operation of electronic equipment, a manufacturing process, a substrate
for multilayer circuitry, and an electronic apparatus. The multilayer
circuit board comprises a laminate of at least one insulating layer and
at least one wiring layer, wherein the wiring layer is formed by a
composite member comprising a first metal layer and a second metal layer
formed on one or both sides of the first metal layer, the first metal
layer having a smaller coefficient of thermal expansion than the second
metal layer, the second metal layer having a higher electric conductivity
than the first metal layer, wherein the insulating layer has a blind
via-hole with a bottom provided by a surface of the second metal layer,
the circuit board further comprising a layer-to-layer interconnection
portion on the surface of the insulating layer and in the blind via-hole,
wherein the layer-to-layer interconnection portion in the blind via-hole
is formed in such a manner as to be in contact with the surface of the
second metal layer.