Highly Manufacturable and Reliable CZT Detectors

Abstract

Cadmium Zinc Telluride (CZT) based radiation detectors have been developed over the past decade and are, increasingly, being used in security and healthcare applications. Improvements in radiation detector performance, size, and cost have been achieved; however, the manufacturability and reliability of the individual CZT detector package continues to limit widespread use and new applications. To date, most CZT detector packages are designed, manufactured, and tested to requirements defined by manufacturers, rather than military, commercial, or industry standards, as is common for semiconductor packages. The lack of test standards has led to use restrictions and/or complex detector system design, as required to mitigate unknown or low detector package reliability. CZT detector packaging, as was the case for semiconductor packaging, has reached the point in technology maturation where a focus on optimizing detector design for manufacturability and reliability is appropriate and necessary. This paper reviews the systematic approach, including design, process development, and testing, utilized in the development and demonstration of a highly manufacturable and reliable (95% reliability at 1000 cycles) CZT detector package. Finite Element Model (FEM) based design and material trade-off studies, development of highly manufacturable and reliable commercial electronic assembly processes, failure mode identification and mitigation, selection and use of reliability test standards, and analyses are detailed for a flip-chip-CZT-on-ceramic substrate, detector package targeted for field deployment. As well, the next steps in package and system design, manufacturing, and reliability testing are proposed.