Reliability of Pixellated CZT Detector Modules Used for Medical Imaging and Homeland Security

摘要

Long term reliability is critical for a detector module to be used in applications that can not afford failure and require high accuracy such as medical imaging and homeland security. In this study, we report the reliability of pixellated Cadmium Zinc Telluride (CZT) detector modules fabricated from crystals grown by the Traveling Heater Method (THM). The reliability of the module which consists of the pixellated detector assembled to a PCB carrier board via conductive epoxy was studied with both a Quantitative Accelerated Life Test (QALT) as well as the Highly Accelerated Stress Test (HAST) which is a common form of a Qualitative Accelerated Life test. The robustness of the THM pixellated CZT detector modules is demonstrated via the pre- and post- accelerated life test comparison of the leakage current and the spectral performance of the assembled module. A shear test was also used to ensure the adhesion strength of the epoxy bonded method. To our knowledge, this type of study on pixellated CZT detector module has been very rare if not the first of its kind.