Patent ID: 7070909
Filing Date: 2006-07-04
Classification: B32B,C03C,D03D,H05K,Y10S,Y10T

Abstract:
1. A method for fabricating printed circuit boards which comprises forming a prepreg of a fiber reinforced polymer substrate containing a woven fiberglass cloth comprising an oxide or salt of at least one member selected from the group consisting of Cu, Cr and mixtures thereof in an amount sufficient to reduce the glass transmittance of UV light having a wavelength of 365 nanometers, impregnated with a thermosetting polymer, laminating a plurality of prepregs, placing a metal foil on both surfaces of the laminate, and then hot pressing the assembly; next, applying a solder resist and subjecting to imagewise irradiation with ultraviolet light in a predetermined pattern for defining the subsequently to be solder coated circuitry.