method for raising a surface to a source of radiation of at least 3000 angstrom length d wave

摘要

The insulating substrate is coated with a soln. of a positive photo promoter and a sensitiser responsive to wavelengths =3000 angstroms. The photo promoter contains an element from Sn, Ti or Pb ions, and their particulate, insoluble, colloidal hydrated oxides (size 10-10000 angstroms), or these ions combined with insoluble, colloidal particles (10-10000 angstroms) of Cr, Fe, Zn, Al and Si. Specif. the sensitiser is (a) an org. dye, (b) charge transfer complex contg. ions in =2 oxidn. states, or (c) transition metal ions. After irradiation, the coated substrate is immersed in the soln. of precious metal salt to deposit the metal selectively on the irradiated areas, forming the desired microcircuit pattern. Opt. this is further plated by conventional means.