Thin film resistors

摘要

Thin film resistors comprising an intimate dispersion matrix of a vapour-deposited conductive metal and a normally solid poly (p-xylylene) which may contain from 25% to 75% by weight of metal, are obtained by condensing and depositing on a surface under reduced pressure, a mixture of a vapourized metal and vapourous p-xylylene divalent radicals, the divalent radicals polymerizing on the surface. The resistors may be supported on insulating substrates or may be self-supporting. Metal foil contacts may be attached to the film or metal contact strips may be vapour-deposited on the surface before the film is deposited. In examples films are deposited on glass slides and on layers of previously deposited polymer; the metals are zinc, germanium, magnesium, silver, aluminium, lead, copper, selenium and cadmium, and the metals are dispersed in poly (chloro-p-xylylene), poly (p-xylylene), and poly (dichloro-p-xylylene). Other polymers mentioned are poly (n-butyl-p-xylylene), poly (iodo-p-xylylene) and poly (tetra-fluoro-p-xylylene) and other metals mentioned are gold, tin chromium, cobalt, titanium, vanadium, manganese, iron, nickel, platinium, tungsten and tantalum. Inert vapours diluents such as N2, A, CO2 and H2O may be used in the vapour system.ALSO:A composition for use as a thin film resistor comprising an intimate dispersion matrix of a vapour-deposited conductive metal and a normally solid poly(p-xylylene) which may contain from 25 to 75% by weight of metal, is obtained by condensing and depositing on a surface under reduced pressure, a mixture of a vaporized metal and vaporous p-xylylene divalent radicals. The divalent radicals are obtained by pyrolysis of a vaporized dimer of formula where Y is an inert substituent, e.g. hydrogen, halogen or a hydrocarbon group, or by pyrolysis of an aryl bis-sulphone of formula where R is a hydrocarbon group and Y is a non-polar substituent, or of a diaryl sulphone of formula where Y is a non-pola substituent. The divalent radicals have the formula and polymerize to form poly(p-xylylene). In examples compositions are obtained of zinc, germanium, magnesium, silver, aluminium, lead, copper, selenium and cadmium dispersed in poly(chloro-p-xylylene), poly(p-xylylene) and poly(dichloro-p-xylylene). Other divalent radicals mentioned are n-butyl-p-xylylene, iodo-p-xylylene and tetra-fluoro-p-xylylene, and other metals mentioned are gold, tin, chromium, cobalt, titanium, vanadium, manganese, iron, nickel, platinum, tungsten and tantalum.