| Abstract:The Dewar window, as one of the core components of infrared detectors, plays a decisive role in the vacuum retention time and long-term stability of the detector. This experiment introduces two types of preformed solder for vacuum brazing, replacing the traditional manual SAC305 solder paste soft soldering process, to study and analyze the appearance quality, hermetic performance, void rate, and welding strength of the Dewar window. The results show that when using SnAgCu composite solder with a middle layer Ni skeleton structure for vacuum brazing, the Dewar window leak rate can achieve a high hermeticity requirement of less than 1×10-12 Pa·m3/s, and the void rate can reduced to 1%. Tensile strength tests on the Dewar window indicate that when the process parameters are set at 250°C, 5minutes, and 0.32MPa, the tensile strength reaches a maximum value of 66.73MPa, which is an increase of 10.19% compared to the traditional manual SAC305 solder paste soft soldered joints. Additionally, this method can improve process consistency and significantly increase production efficiency, which is of great significance for the mass production process of Dewar windows. |