Here is the abstract you requested from the MASH_2007 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Non-Hermetic Packaging of RF Multi-Chip Modules|
|Keywords: Multi-Chip Modules, Non-Hermetic Packaging, Packaging Reliability|
|The packaging of RF multi-chip modules for military applications traditionally employs the use of hermetic, ceramic-based substrates. Although these packaging schemes have proven to be highly robust in a variety of environments, they also carry a significantly higher cost than non-hermetic alternatives. In order to take advantage of the significant cost opportunities available, a multi-chip module was developed using Monolithic Microwave Integrated Circuits (MMICs) in plastic overmolded QFN packages. These devices were subsequently assembled to a PCB built using commercially available processes. In order to make this approach viable, several hurdles needed to be overcome. First, the package had to be designed such that neither the molding materials nor the leadframe design de-tuned the RF circuit. Second, environmental testing was required to prove that this non-hermetic packaging approach would provide ample reliability in a military environment. In the end, the completed assembly was tested and performed almost as well as a ceramic chip and wire module using the same chipset, for less than 25% of the packaging cost. Environmental testing, including temperature cycling, autoclave, HAST and HTOL were also successfully completed, verifying the robustness of this packaging approach for military applications.|
|Matthew Gruber, Senior Member Engineering Staff
Lockheed Martin - MS2