Advanced PCB technologies for space and their assessment using up-to-date standards

The European Space Agency (ESA) in collaboration with its industrial partners has been updating their standards for Printed Circuit Board (PCB) design, qualification and procurement. These standards include design margin to mitigate the risks of latent short-circuit and open-circuit failures, as well as new test and inspection methods for qualification and for lot conformance, such as temperature humidity bias test, conductive anodic filament test, interconnect stress test and dark-field microscopy. The test methods are used to benchmark technology from ESA-qualified PCB manufacturers, and to qualify high-density interconnect (HDI) technology including microvias. To investigate the reliability of the advanced manufacturing methods, various traditional and accelerated thermal stress tests are performed on two and three layers of staggered and stacked microvia configurations, as well as the thermo-mechanical modelling of stress factors. This paper describes the motivation for the updated standards, the benchmarking of novel test methods and first reliability data on advanced HDI technology.