Study On Infrared Device Exhaust Packaging Process Based On A Quadrupole Mass Spectrometer

Uncooled infrared detectors need to work in a certain degree of vacuum and the vacuum life of the device is one of the important technical indicators. The packaging process play a crucial role in the vacuum life of the infrared devices, in particular infrared device package seal welding process and exhaust baking process. Quadrupole mass spectrometer is a partial pressure measuring instruments. It can effectively and dynamic detect the changes of the residual gas composition and content in the measured environment. It has a unique advantage in electronic vacuum devices. The purpose of this dissertation is to optimizing the packaging process of infrared devices in ensuring uncooled infrared detector vacuum life premise. Based on the principle of a quadrupole mass spectrometer, experimental research and optimize device package pivotal leak detection processes and exhaust processes. The main contents include:(1) Study and summarize the structure, the role and the main constituent material of the uncooled infrared detector. By theoretical calculation, research and analysis what is the role the packaging process play in the vacuum life.(2) Research and analysis the structure, working principle, key performance indicators of the quadrupole mass spectrometer and its application in the packaging process in the infrared device.(3) The overall flow of uncooled infrared detectors packaging process are introduced. At the same time, based on the principle of a quadrupole mass spectrometer,theoretical study device package pivotal leak detection processes and exhaust processes and analyzes the process parameters and test methods related to them.(4) In this dissertation, for the poor reproducibility of uncooled infrared detectors packaging process precision leak detection result problems, by increasing the sample point, use with Matlab software to statistical processing the leak testing data from the quadrupole mass spectrometer, greatly improve the leak detection repeatability of results.(5) Experimental study on the effects of uncooled infrared detectors exhaust processes baking temperatures. Using mass spectrometry, the vacuum exhaust system and the uncooled infrared detector main constituent material(metals, ceramics, silver)are respectively studied gassing characteristics of different temperatures bake. Studieshave shown that: the device effective baking temperature is 145 ℃(the device can withstand temperatures up to 160 ℃), and the silver paste material is main source of deflation for the internal device.(6) Experimental study on the effects of uncooled infrared detectors exhaust processes baking time. Using mass spectrometry detection theory, at an effective temperature baking, study gassing characteristics of long bake for uncooled infrared detectors. Study results the outflow phenomena and characteristics of baking time, and ultimately determine the uncooled infrared detector effective baking time is 24 h.