Abstract: A method of fabricating a multilayer superconducting printed circuit board comprises first, forming a bimetal foil to overlie a substrate, the bimetal foil comprising a first layer of a first metal, a layer of a second metal, and a second layer of the first metal, and then etching the second layer of the first metal. Forming a bimetal foil to overlie a substrate may include forming a bimetal foil comprising a first layer of a normal metal, a layer of a superconducting metal, and a second layer of the normal metal. Etching the second layer of the first metal may include preparing a patterned image in the second layer of the first metal for etching, processing the patterned image through a cleaner, rinsing the patterned image, and then, immersing the patterned image in a microetch.

Abstract: A method of fabricating a multilayer superconducting printed circuit board comprises first, forming a bimetal foil to overlie a substrate, the bimetal foil comprising a first layer of a first metal, a layer of a second metal, and a second layer of the first metal, and then etching the second layer of the first metal. Forming a bimetal foil to overlie a substrate may include forming a bimetal foil comprising a first layer of a normal metal, a layer of a superconducting metal, and a second layer of the normal metal. Etching the second layer of the first metal may include preparing a patterned image in the second layer of the first metal for etching, processing the patterned image through a cleaner, rinsing the patterned image, and then, immersing the patterned image in a microetch.

Abstract: A method of cleaning resist residue includes oxidizing the residue. The oxidized residue can be water soluble.

Abstract: A process for electroplating a substrate by coating the substrate with a coating of carbonaceous particles. The coating of particles is applied to the substrate from an aqueous dispersion and then dried by passing the substrates between opposing resilient rollers and preferably passed an air knife.

Abstract: A method of providing an electrically conductive polymer coating on a copper clad circuit board prior to electroplating is disclosed. The method teaches the application of certain organic solvents to a conductive polymer composition already applied to the board but before drying the conductive polymer composition to remove liquids therefrom to form a conductive polymer film.

Abstract: A microetch composition for a circuit board containing sulfuric acid in combination with a carboxylic acid having 2 to 6 carbon atoms, wherein the volume of the carboxylic acid is preferably greater than the amount of sulfuric acid. The method discloses the contacting of a electrically conductive polymer with the microetch composition disclosed above to expose copper underlying the electrically conductive polymer.

Abstract: A process for electroplating a metal clad substrate by coating the substrate with a coating of carbonaceous particles. The coating of particles is applied to the substrate from an aqueous dispersion and then the coating is saturated with an etchant for the metal cladding on the substrate to undercut the carbonaceous coating and facilitate its removal from areas where plating is undesired.

Abstract: A process for electroplating a metal clad substrate by coating the substrate with a coating of carbonaceous particles. The coating of particles is applied to the substrate from an aqueous dispersion and then the coating is saturated with an etchant for the metal cladding on the substrate to undercut the carbonaceous coating and facilitate its removal from areas where plating is undesired.

Abstract: A process for electroplating a substrate by coating the substrate with a coating of conductive particles. The coating of conductive particles is applied to the substrate from an aqueous dispersion containing a dissolution agent for metallic regions of the substrate. The dissolution agent removes the top surface of the metal as the conductive particle coating is formed thereby facilitating removal of the same from the metallic regions of the substrate.

Abstract: A process for electroplating a metal clad substrate by forming a sacrificial coating over the metal cladding and then coating the substrate with a coating of carbonaceous particles. The coating of particles is applied to the substrate from an aqueous dispersion and then the coating is contacted with an etchant for the sacrificial coating to undercut the carbonaceous coating and facilitate its removal from areas where plating is undesired.

Abstract: A process for electroplating a substrate by coating the substrate with a coating of conductive particles. The coating of conductive particles is applied to the substrate from an unstable aqueous dispersion essentially free of a dispersing agent using physical dispersion means to maintain the stability of the dispersion.

Abstract: A process for electroplating a substrate by coating the substrate with a coating of conductive particles. The coating of conductive particles is applied to the substrate from an aqueous dispersion containing a dissolution agent for metallic regions of the substrate. The dissolution agent removes the top surface of the metal as the conductive particle coating is formed thereby facilitating removal of the same from the metallic regions of the substrate.

Abstract: A process for electroplating a substrate having a surface comprising metallic and non-metallic regions. The process is characterized by selectively forming a protective film over the metallic regions of the substrate surface and forming a sulfide coating selectively over the remaining portions of said substrate. The protective film enables selective sulfide formation only on metallic sites without formation of a sulfide coating on metallic surface regions of the substrate which would otherwise interfere with metal-to-metal bond during electroplating. Following formation of the sulfide conversion coating, the protective film is removed and the surface of the substrate electroplated.

Abstract: A process and composition for preparing a nonconducting surface for electroplating. The process comprises contact of the nonconductor with a reaction product of a stannous salt, a noble metal salt and halide ions in acidic solution having a pH not exceeding 3.5. The noble metal salt is present in a amount of from 0.01 and 2.5 grams per liter. The weight ratio of tin to noble metal preferably varies between 150:1 to 700:1. Following contact with the tin-noble metal composition, the surface is contacted with a solution of a sulfur salt able to react with tin and the noble metal to form a sulfide and then electroplated.