The main factor affecting the vacuum life of the infrared detector Dewar is the internal material outgassing. The Langmuir adsorption model outgassing equation is used to calculate the vacuum lifetime due to the outgassing mechanism and the long-term degassing procedure of the Dewar. An innovative method of changing the temperature at the end of the degassing procedure was proposed to obtain the outgassing activation energy. The outgassing rate was measured at different temperatures while simultaneously removing the influence of coverage on the outgassing rate. The out gassing rates at storage temperature and the rule of outgassing rate changing over time were deduced. The difference among the three Dewar outgassing activation energies obtained in different conditions was 8. 8%. The heat load of the Dewar was tracked for two years to verify the method. The estimated error of Dewar's vacuum lifetime was 7. 2%. It is a non-destructive testing estimation method for the vacuum life of small and diverse Dewar.

With the development of infrared imaging technology, especially high resolution imaging instrument for space remote sensing, the requirement of suppressing stray light the optical system is more and more high, thus suppression of stray light of IR detector module as the core device of target detection and imaging is important. The design and processing cold shield is the key of infrared focal plane detector dewar for suppressing stray light, which mainly play a role in suppressing stray light outside of field view and improving background limited detectivity of IR detector. The structure of the cold shield is mainly effect Geometry Composing Function (GCF) of the stray radiation transmission, while Black coatings of cold shield influence bidirectional reflectance distribution function (BRDF) of stray radiation transmission. This paper mainly study suppressing stray light of cold shield with black phosphating process and black nickel plating and point source transmittance (PST) is used as the evaluation index for suppression of stray light, which can be measured accurately. A PST test system in near infrared wave band has been set up for measurement of cold shield’s PST, which coupling infrared light source with light guide tube for greatly improving the uniformity of infrared light source, while the dynamic range of test system decrease slightly. After testing and verification, light source instability is less than 1% , Non uniformity of light source at the exit of the parallel light tube is 7.4%@ 87.5mm×87.5mm.and dynamic range of test system is 0～1.5×10-5, thus the test facility can satisfy PST test of stray light. The PST curve with angle for one stage cold shield with black phosphating process and black nickel plating are measured and consistent with numerical simulation, which first decrease rapidly with increase of the angle, then slowly vary after 35 angle for the structure of one stage cold shield, the results is useful for optimizing design of infrared detector modules for control of stray light.

According to the requirement of the butting short and middle waves long linear IRFPA detectors integrating and coupling with the inline pulse tube cryocooler, the difficulties of the Dewar package were discussed. By studying the temperature uniformity and the supporting structure of long butting substrate, the cold loss and the vacuum life of the large-size Dewar, the three-dimensional thermal output method of the multi-point S type thermlink combined with the conductive layer was proposed, and the supporting structure of bridge with the dual substrate was designed, which were to solve the key technologies of higher temperature uniformity of the long butting substrate, the lower thermal stress of the integrated detector and depth of focus control, space environmental adaptability, lower cold loss and longer vacuum life, the Dewar assembly for the dual-band long linear FPA had been successfully developed, and tested by serial space environment adaptability tests, the results show that those main performances do not change obviously. The Dewar assembly satisfys the requirements of the space application.

Al2O3 and kovar alloy composite component has a wide application prospect in electron packaging,aerospace applications and mechanical engineering,but duet to the distinction of their physical and chemical properties,there exists a large welding residual stress and has difficulty forming good chemical and metallurgical bonding on weld interface.In this paper,the research progresses of vacuum brazing,partial transient liquid phase and indirectly brazing are summarized.And the interface bonding mechanism of Al2O3 and kovar ahoy between filler alloys is elaborated.The development trend of brazing for Al2O3 and kovar alloy is forecasted.

Dissimilar joining between stainless steels and titanium alloys is employed extensively in the chemi-cal,aerospace and nuclear industries,but the property of welding between them is limited by the distinction of their physical and chemical properties.The influences of parameters and compounds of different welding methods on wel-ding quality,mainly including diffusion welding,laser welding and electron beam welding are summarized.The deve-lopment trend of dissimilar joining between stainless steels and titanium alloys is forecasted.

Both 256 × 1 and 512 × 1 element linear near IR InGaAs focal plane array (FPA) modules were hermetically packaged. Some key technologies in packaging structure and process were analyzed, including the heat load performance, high temperature baking performance and sealed package leak rate of the thermoelectric cooler (TEC). The results show that the cooling temperature difference of the TEC can reach above 55 K at room temperature. It drops about 0.51 K when heat load increases 50 mW. It means that the TEC can meets the modules requirements. After a baked test at 120°C with 500 h, the performances of the TEC never change. The sealed package leak rate of the modules meets in the national military standard.

Compared with a cooled infrared detector,an uncooled infrared detector has the advangtages of small size,low weight and low power consumption because it has not any cooler.To improve the encapsulation process of an uncooled infrared detector after exhaustion and achieve its configuration optimization and reliability enhancement,a technical scheme to use laser welding to encapsulate the uncooled infrared detector in high vacuum is proposed.The test result shows that the uncooled infrared detector assembly has not apparent variation in performance and can meet the requirements for actual application.

Highly hermetical laser sealing is a packaging technology which can be used for metal packages.It can achieve the sealing of a small hole of the metal package containing an infrared detector in a high vacuum environment.Thus,both the exhaust process and the sealing process of the infrared detector assembly can be finished at the same time.According to the structure and material of a micro package,the relation of the current and pulse width of a laser welding equipment to welding energy and the influence of the current,pulse width and defocusing distance on welding quality are analyzed.Proper laser welding parameters are obtained for Kovar materials.With those parameters,the laser sealing of a hole of the metal package containing an infrared detector is achieved.The test result shows that its leak rate is better than 1×10~(_10)Torr·1/s.