Fabrication and Characterization of Recycled Polycarbonate-Carbon Nanotubes (RPC-CNT) Derived PCB Insulating Substrates
E.M. Manalastas, B.A. Basilia, I.R. Bello
Mapua Institute of Technology, PH
Keywords: printed circuit board, recycled polycarbonate (RPC), montmorillonite (MMT), carbon nanotube (CNT)
Abstract:Printed circuit board (PCB) substrates are made from different dielectric materials having copper foil on one side as the conducting plane. Researchers are continuously developing materials for the improvement of PCBs to have better physical, mechanical, electrical and thermal properties with low cost and environment friendly. Paper reinforced phenolic resin (PP) or FR-2 is commonly used as a basic PCB substrate in household electrical devices, but since it is a thermoset, this substrate is difficult to recycle. The objective of this study is to investigate the use of recycled polycarbonate (RPC) reinforced with nanoclay/carbon nanotube (CNT) as a potential substrate for PCBs. Using the RPC recovered from used compact disks (CD’s), makes this new PCB an environment friendly substrate because it can be perpetually recycled. The developed substrates were compared with the commercial paper-phenolic (PP) substrate. The following characterization tests were done to evaluate the properties of the RPC reinforced with nanoclay and CNT: Energy Dispersive X-ray spectrometer (EDX), spectral analysis, Atomic Force Microscopy, izod impact test, Rockwell hardness test, thermomechanical tests (coefficient of thermal expansion and glass transition temperature) and electrical test (dielectric constant and dissipation factor). Results show that the new substrate has lower water absorption, better hardness and structural properties, lower dielectric constant and dissipation factor compared with the paper-phenolic resin. After the evaluation, the substrates were laminated with an electrodeposited type of copper foil. The laminated substrates underwent additional characterization such as spectral analysis and EDX of their cross section. Results show that the laminated RPC exhibits acceptable physical, mechanical and electrical properties required for PCB substrates.