Research On Infrared Focal Plane Test System Technology Based On Virtual Instrument

Infrared detectors are widely used in agriculture,military,aerospace,industrial,medical and transportation,and uncooled infrared focal plane detectors have become mainstream of development direction.Uncooled infrared focal plane detectors have non-uniformity due to factors such as material characteristics of the focal plane array,readout circuit design,and environmental changes.In order to reduce non-uniformity,domestic and foreign manufacturers have introduced infrared detectors that integrate on-chip calibration.Wafer testing is required before the infrared detector is packaged to ensure that the on-chip calibration is fully functional and controls production costs.The increasing number of domestic infrared detectors has led to the need for new features in infrared detector testing techniques.Wafer testing is an important part of infrared detector testing technology,and traditional wafer testing systems cannot meet the needs of infrared detection.It is necessary to develop an infrared detector test system capable of testing voltage,current,resistance and on-chip calibration functions.At the same time,the test system needs to be versatile,efficient and stable,and optimize the processing of test results in order to judge the chip function.This paper takes this as the research background,and conducts in-depth research on the construction of infrared test system and the preparation of infrared test software.This paper builds a test system for infrared detector wafer testing.The selected virtual instruments are divided into power modules,timing modules,acquisition modules and measurement modules according to their functions.Use the appropriate PXI card to build functional modules that are compatible with the testing of different types of detectors.A set of automated test software was designed.The main task is to drive the test system equipment to complete the test and measurement work.The software architecture can be divided into a driver layer,an application function layer,and a human-computer interaction layer.The driver layer encapsulates the drivers for virtual instruments,including voltage output,digital timing generation,signal measurement,and image data acquisition.Application function layer encapsulation software function,undertake human-computer interaction layer and driver layer,including signal processing module,data processing module and file saving module.Thehuman-computer interaction layer encapsulates the human-computer interaction function,and uses the MVP design mode to reduce the software coupling degree,including the Model module,the View module,and the Presenter module.The entire test software can adjust the test parameters in the engineer mode,and complete the test items according to the test logic requirements during the automated test process.A programmable digital on-chip calibration method is designed for on-chip calibration.The digital on-chip correction method can be realized by changing and writing a frame timing signal in real time using the stream mode and the double buffer mode.For different types of detectors,only one frame of timing signals needs to be designed and stored to perform timing drive and on-chip correction.Optimized test data processing methods,including judging bad points clusters,processing configuration files,and optimizing file saves.Bad clusters have different shapes and contain a different number of bad points.The case of distinguishing the bad clusters by judging the cluster shape of the bad points.