Molding method of integrated cold shield for infrared detector

Abstract

The invention discloses a molding method of an integrated cold shield for an infrared detector. Extinction fins of the cold shield are directly electro-casted with a cold shield body, secondary bonding is avoided, glue for packaging is effectively controlled, the vacuum service life of the detector can be maintained for long time; and design of the cold shield body is simplified, bonded fitting and positioning surfaces are not embodied in the cold shield body, the total weight of the cold shield is decreased, power requirement for a refrigerator is lowered, and work of the cold shield is higher.

Description

technical field [0001] The invention relates to the field of material technology, in particular to a method for forming an integrated cold screen for an infrared detector. Background technique [0002] At present, the life expectancy of the second-generation and third-generation cooled infrared focal plane detector components is generally about 15 years. The main factor affecting its life is the vacuum life of the detector micro-Dewar, and the vacuum life of the Dewar mainly depends on the package. For the outgassing of various internal parts (including detector chips, cold screens, ceramic substrates and optical filters, etc.), due to the electrical lead-out and low-temperature working characteristics, low-temperature epoxy bonding is used between each part The organic epoxy glue will slowly decompose in a high vacuum environment to form various small molecular gases such as H2, H2O, and CO, which will eventually cause the vacuum in the detector Dewar to fail. As an import...

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Problems solved by technology

[0002] At present, the life expectancy of the second-generation and third-generation cooled infrared focal plane detector components is generally about 15 years. The main factor affecting its life is the vacuum life of the detector micro-Dewar, and the vacuum life of the Dewar mainly depends on the package. For the outgassing of various internal parts (including detector chips, cold screens, ceramic substrates and optical filters, etc.), due to the electrical lead-out and low-temperature working characteristics, low-temperature epoxy bonding is used between each part The organic epoxy glue will slowly decompose in a high vacuum environment to form various small molecular gases such as H2, H2O, and CO, which will eventually cause the vacuum in the detector Dewar to fail.

As an important part of the detector to limit the optical path and eliminate stray light, the cold screen is generally designed with several extinction fins (such as figure 1 As shown), due to the material and thin-wall factors, the structure cannot be integrally formed by conventional machining methods. The usual method is to machine the fins, and then use low-temperature epoxy glue to bond them to the inner wall of the main body of the cold screen. This process Due to the introduction of excess organic matter (glue) in the fin bonding process, it is not conducive to the maintenance of the vacuum life of the Dewar

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