Definition

Laser drilling uses focused laser energy to ablate PCB material, creating micro-vias too small for mechanical drills. CO2 lasers (10.6 µm wavelength) ablate dielectric but stop on copper, used with copper-windowed structures. UV lasers (355 nm) can ablate both dielectric and thin copper, enabling blind via formation without pre-etched windows. Laser drilling is faster and more precise than mechanical for small holes but limited to ~150 µm minimum diameter and shallow depths (typically single-layer). Direct laser ablation is used for buried/blind via processing.