Abstract: An improvement is obtained in the bond strength between members of a laminate comprising a plastic substrate and a metal film through a process of first laminating to the plastic substrate a thin, sacrificial, anodized metal foil by heat and pressure, chemically stripping the foil from the substrate surface, activating the surface for electroless plating and electrolessly depositing a metal thereon, wherein the substrate is contacted with an aqueous solution containing an organic silicon compound at some stage subsequent to said chemical stripping operation. The final metal film when applied to the substrate exhibits consistently better adhesive strength than is obtained without the organic silicon treatment.

Abstract: Circuit boards for electronic equipment are produced in which the circuit-forming conductor metal is deposited on a suitably catalyzed and masked resin substrate by an all-additive electroless deposition technique, in which the characterizing feature is the use of a two-stage metal deposition to build up the desired total thickness of metal. In the first stage a fine grained, thin deposit of metal is produced on the substrate which is then water rinsed and immersed in a second metal bath having a sufficiently high rate of deposition to produce the desired total thickness of metal in a commercially practical period of time. Improved adhesion of plated metal to the resin substrate, both before and after thermal shock, is achieved by resort to this two-stage plating procedure.