<p>R esistance brazing is commonly employed for high-throughput joining of copper-based electrical assemblies. However, the reliability of these joints is significantly influenced by a narrow process window and by microstructural features that can lead to brittle fracture and electrical degradation. This work integrates (i) a targeted review of brazing fundamentals and resistance brazing practice for starter-motor manufacturing with (ii) an industrial case study on SIL-FOS 15 (Cu-15Ag-5P) brazing joints used to connect armature conductors to commutator segments. The review consolidates the roles of heat input as a current–time waveform, electrode force, and the resulting contact resistance, joint clearance-driven capillary flow, and surface oxidation and cleanliness in controlling wetting, defect formation (e.g., porosity and incomplete fill), and interfacial reactions. The case study combines optical microscopy with SEM-BSE/EDS to resolve phase distribution and diffusion features and pull tests (<i>n</i> = 20) to assess repeatability. The brazed zone exhibited an α-Cu matrix with Ag-rich eutectic regions and P-containing phases, including Cu₃P and a ternary Cu-Cu₃P-Ag eutectic. While phosphorus enhances deoxidation and wetting, excessive Cu₃P can reduce toughness; therefore, microstructure-aware parameter control is required. Pull loads ranged from 2439 to 3118 N (mean 2744 N and CV 6.8%), demonstrating robust and repeatable joining under industrially relevant conditions. The paper concludes with a process-microstructure-failure robustness perspective and actionable recommendations for manufacturing optimization.</p>