Patterning of aluminum metallized pet film using high repetition rate fiber laser

Abstract

The authors propose a method for rapid laser isolation of a 12 μm-thick aluminum (Al) metallized polyethylene terephthalate (PET) film. The laser patterning system employed a cost-effective, nanosecond-pulsed master-oscillator power amplifier fiber laser. A dynamic focusing configuration was adopted as a replacement of conventional telecentric lens setup for beam focusing and beam delivery. The ablation process caused thermal removal of Al, and the effects of processing parameters on ablated channels' width, depth, edge quality, and electrical isolation were investigated. It was found that a higher deposited laser energy caused the kerf width to increase. The chance of electrical isolation also increased with it at a cost of risk to damage surrounding electrode and substrate layers. Based on the findings, a processing recipe was established. Channels with a minimum width of 42 μm could be produced at a scan speed of 900 mm/s without visible collateral damage inflicted to the PET film. Finally, the process was modeled using the finite element method and validated against the experimental data.