Review of Welding Technologies for Electronic Precision Equipment: Status, Limitations, and Prospects

This review examines the application of mainstream welding technology in electronic precision equipment, focusing on the matching relationship between the three dimensions of joint strength, spatial adaptability and welding deformation and the requirements of electronic precision equipment. The authors critically evaluated the application status and physical limitations of vacuum brazing, electron beam welding, friction stir welding and laser-arc hybrid welding in the field of electronic precision equipment. A criterion-based comparison table and a unified classification of the physical limitations are provided to support technology selection. On this basis, this paper further discusses the microstructure characteristics of each welding method and the regulation mechanism of key process parameters on joint performance. The review finally points out that the current engineering bottleneck is not the lack of connection ability, but the coupling constraints among thermodynamic constraints, material intrinsic physical properties constraints and spatial geometric contradictions, and proposes the expected direction of future engineering breakthroughs.