| 摘要 |
751,445. Printed circuits. PRITIKIN, N. Aug. 12, 1954 [Aug. 17, 1953], No. 23413/54. Drawings to Specification. Class 36. An inlaid circuit is made by chemically cleaning one surface of a metal sheet in a desired circuit pattern, the remaining portions of the surface being protected by a non-conducting resist, electrolytically applying a metal different from that of the sheet to the clean surface, applying insulating material in plastic form thereover and removing the metal sheet by means of a solvent which is substantially inert towards the materials of the circuit. The resist may be applied to a copper base as a photosensitive coating which is exposed to the negative pattern of the circuit, developed and fixed so that the non-exposed portions are washed away. After cleaning in sulphuric acid, silver is electrolytically deposited on the exposed portions of the base, the reverse side of the base being suitably coated to prevent deposition thereon. The remaining parts of the resist may then be removed with an organic solvent which does not harm the copper base in the deposited silver. Polystyrene or Teflon is applied over the treated surface and pressed to ensure firm and uniform contact, after which the copper base is removed by an aqueous solution of ferric chloride. The resins may be applied to the base by printing, rolling or screening and, if it is compatible with the insulating material it need not be removed after the electrolytic process. Various metals may be used for the base sheet and conducting pattern, the solvent for the base being selected accordingly. Specification 639,178 is referred to. |
