Improvement of Longest Vacuum Holding-Time in Dewar Assembly for Infrared Focal Plane Array Detector

We addressed the two major problems:the pressure build-up in Dewar assembly and increasing blind pixels of infrared focal plane array (IRFPA) detector. First, the surface outgassing of Dewar assembly, compressing Dewar, IRFPA chip and getter material, was mathematically modeled, theoretically analyzed and experimentally evaluated with the lab-built test platform to predict the longest vacuum-holding time. Next, the influence of the baking temperature and time on the storage life of infrared chip was investigated. The results show that the baking temperature and baking time all have a major impact on the simultaneously failure of both vacuum and infrared chip. And finally, the Dewar assembly for an IRFPA detector was tested for optimization of baking conditions. Baked at 90℃ for 16 d, the longest storage time of the Dewar assembly at 30℃ was estimated to be 14y.