Selective Metallization of Thermoplastic Elastomers Based on Laser‐Induced Surface Activation

Abstract

Laser direct structuring (LDS) technology successfully realized the selective metallization on thermoplastic elastomers. Polystyrene‐block‐poly(ethylene‐co‐propylene‐block‐polystyrene copolymer (SEPS) and polyether‐block‐amide (Pebax) containing 5 wt% Cu2(OH)PO4 are designed as LDS materials. Copper layers are obtained after NIR laser activation and metallization. The analysis of morphologies (optical microscope, scanning electron microscopy, confocal laser scanning microscopy), the chemical composition (X‐ray photoelectron spectroscopy [XPS], Raman, X‐ray diffraction), and the performance (scotch tape test, resistance) of materials before and after laser activation and metallization are carried out. The key to obtaining a high‐quality metal layer is as follows. 1) Cu2+ is reduced to copper (Cu0) with amorphous carbon acting as a reducing agent, and Cu0 acts as catalyst seeds in metallization. 2) The good adhesion between polymers and copper layers comes from the micropores etched by laser activation. In particular, XPS shows that 64.6% Cu2+ in SEPS/Cu2(OH)PO4 is reduced to Cu0, while only 18.4% Cu2+ in Pebax/Cu2(OH)PO4 is reduced after laser activation. Moreover, resistances of copper layers on SEPS/Cu2(OH)PO4 and Pebax/Cu2(OH)PO4 are 0.96 and 5.04 Ω, respectively. This study puts forward a way of fabricating flexible LDS materials. The prepared SEPS/Cu2(OH)PO4 composite is promising for shape variable decoration and flexible electronic devices.