We present an experimental investigation into the selective micro-laser melting (SMLM) technique applied to create conductive traces using commercially available lead-free solder paste on a polylactic acid (PLA) polymer structural member. Unlike traditional heating methods such as furnaces or ovens, SMLM allows for precise localized heating, enabling the formation of intricate 3D printed interconnects or traces on low heat deflection temperature (HDT) polymers. Our approach aims to achieve superior conductivity that closely mimics the electrical properties of bulk metals. This study focuses on analyzing the melted traces of Sn-3%Ag-0.5%Cu (SAC) without causing any deformation to the low HDT PLA polymer substrate. We explore the impact of energy density and energy deposition rates on the characteristics of the conductive traces. Melted continuous conductive traces were fabricated for a fixed laser power of 1.6 W and for work speed greater than 90 mm/min. Intriguingly, our findings reveal that the rate of energy deposition significantly influences the dimensions of the melted interconnects or traces, even when maintaining a consistent energy density. These results highlight the need for further comprehensive analysis and precise quantification of the optimized process parameters to obtain melted interconnects or traces that exhibit robust electrical conductivity.