Abstract:
A method for enhancing the solderability of a metallic surface is disclosed where the metallic surface is plated with an immersion or electroless silver plate prior to soldering, after which immersion silver plate is treated with an alkaline polymer coating comprising aqueous vinyl polymers, aqueous acrylic polymers, anti-fungal agents and a benzotriazole or benzimidazole compound to produce a deposit that is resistant to electromigration and that provides an anti-tarnish and anti-corrosion coating on the surface.
Abstract:
The present invention is directed to a microetching composition comprising a source of cupric ions, acid, a nitrile compound, and a source of halide ions. Other additive, including organic solvents, a source of molybdenum ions, amines, polyamines, and acrylamides may also be included in the composition of the invention. The present invention is also directed to a method of microetching copper or copper alloy surfaces to increase the adhesion of the copper surface to a polymeric material, comprising the steps of contacting a copper or copper alloy surface with the composition of the invention, and thereafter bonding the polymeric material to the copper or copper alloy surface.
Abstract:
Multilayer printed circuit boards are fabricated by preparing a first layer in conventional manner by forming a resist image on a copper clad substrate, etching away unwanted copper, removing the resist from the circuit pattern and optionally applying a dielectric mask such as conventional solder mask to selected portions of the circuit pattern. A second layer, and optionally one or more subsequent layers, are fabricated by providing an image of a second circuit pattern in a predetermined location on said first layer, the image being formed using a suspension of cuprous oxide in a curable resin material. The image is cured at least partially and subjected to chemical reduction to convert at least a portion of the cuprous oxide to metallic copper. The image is then electrolessly plated with copper to build up the circuit pattern and the latter is selectively coated with a dielectric mask before repeating the cycle to build up one or more additional layers. Solder can be applied to selected areas of any of said printed circuit layers at any appropriate time during fabrication. The above method of fabrication has advantages of economy of time, materials and labor as compared with methods hitherto employed to prepare multilayer boards in which a plurality of single boards are fabricated individually and then assembled as a sandwich or laminate by application of heat and pressure.
Abstract:
A process is described for treating metal surfaces with roughening compositions that use poly(ethyleneamino propionitrile) polymer as an additive in the composition to improve adhesion of polymeric materials to the metal surfaces and to improve peel strength for thermal stability. The polymer of the invention may be added to compositions containing for example, cupric chloride and hydrochloric acid and is also usable in compositions containing an oxidizer/acid/azole mixture. Other additives, such as adiponitrile may also be beneficially added to compositions of the invention.
Abstract:
The present invention is directed to a microetching composition comprising a source of cupric ions, acid, a nitrile compound, and a source of halide ions. Other additive, including organic solvents, a source of molybdenum ions, amines, polyamines, and acrylamides may also be included in the composition of the invention. The present invention is also directed to a method of microetching copper or copper alloy surfaces to increase the adhesion of the copper surface to a polymeric material, comprising the steps of contacting a copper or copper alloy surface with the composition of the invention, and thereafter bonding the polymeric material to the copper or copper alloy surface.
Abstract:
A method for enhancing the solderability of a metallic surface is disclosed where the metallic surface is plated with a silver plate prior to soldering, which immersion silver plate is treated with an additive comprising a mercapto substituted or thio substituted silane compound. Preferred post treatments comprise 3-mercapto propyl trimethoxysilane and/or 3-oxtanoylthio-1-propyltriethoxy silane.