Development of Mechanical and Environmental-Test Procedures for Transmit/Receive Modules

Phased array designs for microwave and communication applications incorporate large numbers of transmit/receive (T/R) modules. High part counts lead to concern about T/R module reliability and improvements in semiconductor device manufacturing techniques and materials technology make lifetime performance data difficult and expensive to acquire. Accelerated life testing (ALT) provides a means by which reliability may be characterized in a compressed time frame. TRI/Austin will collect mission profile data for T/R modules, from which an ALT will be designed using theoretical aging models and analysis of service life failure mechanisms. Finite element analysis will be carried out for materials that are used in T/R module designs; stresses imposed by environmental and operational conditions will be estimated. Thermal analysis techniques will be used to investigate thermal aging effects for selected materials. Component-level GaAs test articles will be subjected to thermal cycling, and the cycles to failure will be recorded for varying test article configurations. Results will be compared with FEA and theoretical predictions. Nondestructive evaluation will reveal the presence of cracking or other GaAs failures, and several NDE techniques will be examined for applicability to failure detection in GaAs semiconductor designs.