Laser-induced surface texturing enables selective copper metallization on alumina via precise ligand adsorption

Creating high-precision conductive lines on alumina substrates is a significant challenge in advanced circuit manufacturing, which is constrained by complex processes and environmental sustainability. We present a laser-assisted copper activation pretreatment for alumina metallization. The selective activation has been achieved both on the surface and in the holes of alumina ceramics through the synergistic coupling between laser-textured surface regions and copper-active particles. High-resolution metallization layers with excellent surface quality are then produced on the alumina surface using simple electroless copper plating (ECP), demonstrating excellent stability and weldability. The optimized conductive layers exhibit a sheet resistivity of approximately 1.1 mΩ/□ and a minimum line width of 50 μm. Additionally, this technique is compatible with through-ceramic-via (TCV) sidewall metallization, enabling both circuit patterning and vertical interconnection on the substrate. This new approach offers significant benefits over traditional methods, including a simplified workflow, reduced chemical hazards, and superior resolution, making it promising for multi-layer wiring and through-hole vertical interconnection in ceramic-based high-density circuit substrates.