Patent ID: 6579660
Filing Date: 2003-06-17
Classification: G03F,H05K,Y10S,Y10T

Abstract:
A blank printed circuit board (PCB), for creating a circuit pattern thereon by direct imaging with infrared radiation, comprising in sequence an insulating substrate, a metal layer, a resist layer and a mask layer, wherein:the resist layer has been deposited from an organic solution, has a thickness of between 3 microns and 30 microns and includes three components a first component, constituting 35% to 75% of the resist layer by weight and including acrylic monomers and oligomers, capable of polymerising when and where irradiated by ultraviolet radiation in the presence of photoinitiators, such polymerisation constituting curing of respective portions of the resist layer, a second component, constituting up to 10% of the resist layer by weight and including photoinitiators and synergists, and a third component, constituting 10% to 50% of the resist layer by weight and including binder resins that are soluble in water or in dilute aqueous alkali solvents, as well as in non aqueous solvents; the mask layer has been deposited from an aqueous suspension, has a thickness of between 0.3 microns and 6 microns, and includes between 80% and 100% by weight of carbon black and not more than 10% by weight of binder resins.