Abstract: Oxygen-free copper is widely used in liquid cooling systems for efficient heat dissipation, and its brazing quality directly affects the reliability of the liquid cooling system. In this study, the effects of brazing temperature curve and applied load on the brazing rate and interface microstructure of large oxygen-free copper components were investigated. The results indicate that the joint achieves the highest brazing rate of 85.71% at a peak brazing temperature of 720 ℃ with short holding time, with no obvious filler overflow or defects. Both excessively low and excessively high peak temperatures lead to a decrease in brazing rate. At 680 ℃, prolonging the holding time promotes filler metal melting and thus improves the brazing rate, but also intensifies filler overflow. During the brazing of large copper plates, simultaneous loading at the center and four corners is essential. Increasing the center load under an appropriate corner load enhances the brazing rate. The optimal configuration 2.5 N·m at the corners and 4.0 N·m at the center achieve a maximum brazing rate of 83.37%. Both prolonged holding time and elevated peak temperature promote the growth of the Cu solid solution(Cu_ss) at the interface. However, excessively high temperatures or extended durations facilitate pore formation. In contrast, variations in external loads show no significant effect on the interface microstructure or defect population.