| 摘要 |
A blank printed circuit board (10), for creating a circuit pattern thereon by direct imaging with infrared radiation. The blank printed circuit board (10) includes in sequence an insulating substrate (20), a metal layer (21), a resist layer (22) and a mask layer (23). The resist layer (22) 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 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 layer by weight and including photoinitiators and synergists; and the third component, constituting 10% to 50% of the layer by weight and including binder resins that are soluble in water or in dilute aqueous alkali solvents, as well as nonalkali solvents. The mask layer (23) has been deposited from an aqueous suspension which 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. |
