A novel approach of a laser-based hybrid microscribing of copper coated on a dielectric material is proposed and demonstrated. The pulsed ablation of Cu coated dielectric substrate immersed in sodium chloride (NaCl) aqueous solution results in high temperature. At elevated temperatures, copper ions react with Cl− ions in NaCl to form CuCl2 compound, which is soluble in water. The convective motion in the solution due to the temperature gradient is expected to remove the debris and prevent recast or redeposit formation. The influence of laser pulse duration on this hybrid laser-based microscribing is studied. Further, it is observed that the application of a DC voltage between the sample and a tool electrode improved the surface morphology. Fabrication of a frequency selective surface (FSS) working in the X-band (8-12 GHz) is demonstrated using the proposed technique.
Keywords: Microscribing, salt solution, hybrid machining, frequency selective surface