Arc wire-based Direct Energy Deposition (DED) technology is an essential additive manufacturing process that exhibits a high deposition rate and heat accumulation. This technology is advantageous due to its efficient production at a low cost. The process utilizes an electric arc for heat source and metal wire for feed material. After path planning, it creates three-dimensional metal parts layer by layer. In order to prevent defects from affecting the service condition and lifespan of the parts, it is crucial to focus on the evolution of the microstructure and the enhancement of the mechanical properties during the deposition process. During metal parts manufacturing using Arc wirebased DED, defects such as residual stresses, porosity, deformation, and cracking are generated due to the complex thermal cycle and high heat input. This paper provides a concise overview of the process and methodology involved in Arc wire-based DED, along with an analysis of the resulting microstructure and material properties. This review also outlines means of controlling the heat input, as well as pre-treatment, in-process, and post-treatment methods for controlling the defects and microstructure to improve the properties of the workpieces. Finally, the paper offers insights into achieving high-quality, defect-free workpieces using Arc wire-based DED and provides recommendations for future DED development.

As electronic packaging technology strives for miniaturization, integration, and multifunctionality, System in Package (SiP) technology faces new challenges. This study delves into Laser Jet Soldering Ball Bonding (LJSBB) technology as an alternative to traditional ball bonding techniques to reduce costs and enhance reliability. Using the method of controlling variables, the study systematically analyzed the impact of three key process parameters: laser power, heating time, and nozzle height, on the morphology of solder joints, coplanarity, and shear strength, revealing their mechanisms of influence. The experimental results indicate that increasing laser power and extending heating time can raise the temperature of the solder ball melt pool, causing the solder joints to flatten, directly affecting coplanarity; increasing nozzle height can make the solder ball move more violently upon contact with the pad, affecting its solidified shape and thus coplanarity. Additionally, it transforms the intermetallic compound (IMC) layer from a dispersed discontinuous state to a continuous thin layer, significantly enhancing the shear strength of the solder joints. Furthermore, through response surface experiments, the study analyzed the interactions between various process parameters. It verified the optimization results of the response surface, which were found to have a minimal error compared to actual values.