Crack defects in ceramic welding are a significant challenge in electronic packaging that requires urgent resolution. In this study, fiber laser-based welding was employed to join 1 mm thick Al2O3 ceramic plates. The investigation focused on weld surface formation, crack defects, and performance attributes across varying heat input and preheating temperatures. The findings indicate a propensity for crack initiation at the weld center or within the base material during Al2O3 ceramic laser welding. Nonetheless, the susceptibility to cracking in Al2O3 welded joints can be mitigated, and joint fle...