Abstract: The linewidth in patterns produced by etching copper layers is more easily maintained using a specific etching medium. In particular, this medium includes aqueous hydrofluoric acid, copper chloride, and an additional chloride salt. The etching medium is also particularly useful for bilayer metal constructions such as the copper/titanium structure found in many multichip modules.

Abstract: A triazine-based mixture, used as a multichip module device dielectric (14), is made more robust and more resistant to temperature extremes by making it to be of from twenty to sixty percent by weight of triazine and of one to ten percent by weight of siloxane-caprolactone copolymer. The foregoing mixture can be made to have a higher resolution by including zero to twenty percent by weight of novolak epoxy acrylate. The entire mixture preferably additionally comprises two to eight percent by weight of bisphenol-A diglycidyl ether monoepoxyacrylate, zero to twenty percent by weight of carboxyl-terminated butadiene nitrile rubber, two to six percent of N-vinylpyrrolidone, one to ten percent of trimethylolpropanetriacrylate, zero to five weight percent glycidoxypropyltrimethoxysilane, 0.05 to five weight percent photoinitiator, zero to two percent pigment, 0.1 to one percent surfactant, zero to 0.3 percent copper benzoylacetonate, and thirty to fifty percent solvent.

Abstract: The linewidth in patterns produced by etching copper layers is more easily maintained using a specific etching medium. In particular, this medium includes aqueous hydrofluoric acid, copper chloride, and an additional chloride salt. The etching medium is also particularly useful for bilayer metal constructions such as the copper/titanium structure found in many multichip modules.