Method for using photoabsorptive coatings and consumable copper to control exit via redeposit as well as diameter variance

摘要

A method of forming a through-via in a laminated substrate by applying a polymeric photo-absorptive layer on an exposed bottom surface of a laminated substrate. A through-via is laser drilled in the substrate from a top of the substrate through the substrate to a bottom of the substrate. The photo-absorptive layer formed on the bottom surface of the substrate is then removed.