Laser-Induced Selective Metallization on Polymers for Both NIR and UV Lasers: Preparing 2D and 3D Circuits

Abstract

Laser-induced selective metallization (LISM) technologies have received much attention because of their applications in metallized patterns and two-dimensional (2D) and three-dimensional (3D) circuits. Our work proposed a new laser sensitizer, copper pyrophosphate (Cu2P2O7·3H2O), which can perform LISM for both 1064 nm near-infrared (NIR) laser and 355 nm ultraviolet (UV) laser. Conductivities of copper layers obtained by NIR and UV LISM on the ABS/Cu2P2O7 composite were 1.52 × 107 and 1.47 × 107 Ω–1·m–1, respectively. The copper layer adhesion to composites reached the 5B Level of ASTM D3359. Thermal gravimetric analysis (TGA) and X-ray diffraction (XRD) revealed that Cu2P2O7·3H2O changed color due to the loss of crystalline water during composite preparation. Scanning electron microscopy (SEM), optical microscopy (OM), and Raman imaging indicated that a microrough structure and amorphous carbon appeared on composites. X-ray photoelectron spectroscopy (XPS) revealed that Cu2P2O7·3H2O was reduced to Cu0 after laser activation, and this Cu0 was the active species to induce electroless copper plating (ECP). About 54.39 and 30.57% of Cu2+ were reduced to Cu0 after NIR and UV laser activation. NIR laser can generate more Cu0 due to a higher thermal effect, so the speed of ECP is faster. In addition, decorative patterns and interdigitated capacitor patterns were successfully fabricated on 3D plastic parts by LISM, demonstrating potential application prospects.