Single-sided conductor patterned films are prepared, each of which has a
conductor pattern formed only one side of a resin film and via hole filled
with conductive paste. A single-sided conductor patterned film which has a
conductor pattern formed only one side of a resin film and an opening
formed in the resin film so as to expose an electrode is laminated on the
single-sided conductor patterned films. Moreover, a cover layer with an
opening to expose an electrode is laminated on a bottom surface of the
single-sided conductor patterned films to form a laminate. Then, by
pressing while heating the laminate, a multilayer substrate having the
electrodes at both sides thereof can be produced.
