| 摘要 |
PROBLEM TO BE SOLVED: To improve adhesiveness, signal propagating property, soldering heat resistance, and resistance to cracking of a lower-layer conductor circuit by forming a metallic layer of one or more kinds of metals selected from among specific long-period metals (excluding Cu) on the periodic table, Al, and Sn on at least part of the surface of the circuit. SOLUTION: On the surface of a resin insulating layer, a thin metallic layer composed of one or more kinds of metals selected from among the fourth- to seventh-period metals in the groups from group 4A to group 1B, Al, and Sn on the periodic table is formed by plating, etc. Since the polyolefin resin forming an interlayer insulating layer has a high adhesiveness to an inner-layer conductor circuit 9, it is not required to roughen the surface of the circuit 9 and the circuit 9 can have a flat surface. Since the permittivity constant and dielectric loss tangent of the polyolefin resin are <=3 and <=0.05, respectively, both of which are lower than those of an epoxy resin, the conductor circuit 9 can propagate signals without delay even when the signals are high-frequency signals. In addition, since the polyolefin resin has a heat resistance which is not inferior to that of the epoxy resin and a high fracture toughness value and does not come off the conductor circuit 9 even at its melting temperature, the resin does not cause cracking. |
