| 摘要 |
<p>1,013,606. Printed circuits. SIEMENS & HALSKE A.G. Feb. 6, 1964 [Feb. 6, 1963 (2)], No. 6088/64. Heading H1R. A printed circuit is formed on an insulating carrier 1 by a process comprising the following steps: (a) A first adhesive layer 7, e.g. a mixture of polyamide and epoxy resins, and a second adhesive layer 8, e.g. a synthetic rubber adhesive, are applied to the roughened major surfaces of the carrier 1, by brushing, spraying, or a centrifugal process, and are hardened; (b) Holes 3 are provided where required in the carrier, as by drilling; (c) The carrier is pre-activated and seeded with tin and 'palladium; (d) A layer 9 of copper is applied by an electroless process, e.g. reduction, and consolidated and thickened by electrolysis; (e) Stencils 12 are applied to the carrier surfaces to define the desired circuit pattern; (f) Parts of layer 9 exposed through stencils 12 are thickened by electrolytic deposition of copper 13 and an etch-resistant metal 14, e.g. gold, silver, rhodium. (g) The stencil is removed and the unwanted portions of copper layer 9 are etched away. When a single-sided circuit is required, the copper layer on the reverse side may be removed electrolytically during step (f), or a pair of carriers may be stuck together during step (d) to prevent the formation of a copper layer on the reverse side.</p> |
