Reliability of Indium Solder Joints using a Laser-Assisted Bonding (LAB) Process at Room Temperature

This study introduces a Room-Temperature Laser-Assisted Bonding (LAB) process using indium solder and a proprietary laser Non-Conductive Paste (NCP) for eco-friendly, low-temperature electronic component bonding. Indium solder's low melting point and high conductivity offer advantages over traditional SnAg solder, eliminating the need for high-temperature processes. The present research focuses on optimizing LAB parameters including laser power and irradiation time to achieve reliable solder joints at 25°C without a cleaning process. Reliability is assessed through bump resistance, Damp-Heat (DH), and Thermo-Cycling (TC) tests, complemented by a microstructural analysis using Optical Microscopy (OM), Scanning Electron Microscopy (SEM), and Energy Dispersive Spectrometry (EDAX). The obtained results confirm the process's effectiveness in fine-pitch bonding applications, promising advancements in heat-sensitive component manufacturing.