| 摘要 |
PURPOSE:To obtain a copper covered laminate having superior electrical characteristics by oxidizing the surface of copper foil so as to protect the surface from moisture, contaminants, sprayed brine, etc. CONSTITUTION:A treating soln. contg. about 30g/l NaClO2, about 5-10g/l NaOH and about 5-10g/l Na3PO4 is prepd. and kept at about 90-95 deg.C. A copper covered laminate having a copper foil circuit pattern on the insulating substrate is immersed in the treating soln. for about 2-5min to uniformly form a copper oxide film of CuO or Cu2O on the surface of the copper foil. Unlike a coated plastic film the copper oxide film has a nearly uniform thickness, so a copper covered laminate whose electrical characteristics such as dielectric loss tangent, dielectric constant and loss are stable is obtd. Since the copper oxide film is chemically stable, it is effective in preventing the chemical deterioration of the surface of the copper foil. |
