An optimized Ni P seed layer coating method for through glass via (TGV)

Through Glass vias (TGV) metallization can realize the interconnection of components between the circuit boards. Metallic seed layer is required in order to realize copper filling through via. Vias are created by hydrofluoric acid etching based on photosensitive glass. The glass modification only adopts physical roughening instead of chemical modification. The paper chose Nickel activation and NiP electroless plating. Nickel activation process were optimized so that seed layer completely covered the glass with high aspect ratio (10:1). Annealing treatment was studied for improving the contact adhesion. The NiP seed layer achieves electroplating filling function.