Combining Molecular Interaction and Physical Anchoring Effect to Achieve Ultra-High Adhesion Electroless Copper Plating on Glass Substrates

High-adhesion metallization on glass substrates has consistently been one of the technical challenges in using glass as the substrate in high-performance integrated circuit (IC) carriers. To improve the adhesion of electroless copper layers on glass substrates, this study developed a nano-palladium catalyst capped with 3-aminopropyltriethoxysilane (APTES) as a self-adsorbing activator for electroless copper deposition, paired with a thin porous titanium dioxide (TiO₂) adhesion-promoting layer. This approach successfully increases the adhesion strength of the electroless copper layer to 1392 gf cm⁻¹, significantly exceeding the practical target value of 500 gf cm⁻¹. Experimental and analytical results confirm that the high adhesion is due to the formation of Si-O-Ti bonds between APTES-Pd and TiO₂, allowing the electroless copper to firmly deposit on the TiO₂. Additionally, the porous TiO₂ layer provided extra physical anchoring, further enhancing the adhesion.