New technologies for board level interconnect and packaging

During late 1990s, there have been many advances in board level packaging. These advances have allowed space payload designers to decrease the weight of units that they design. These advances have also allowed both electrical and product designers to incorporate new technologies to improve unit level functionality. Examples of these advances include area array packages such as the plastic ball grid array (PBGA) which offers better printed wiring board (PWB) area utilization and microvia PWBs which allow greater routing density and hence better board area utilization. Although these advances are significant, there are collateral effects that arise because of the higher routing density mentioned above and because of the constant improvements in component technology. However, increased board density and design methodologies to reduce cross-talk for example can work against each other. New technologies which can alleviate some of the issues described above are being developed. An example of near term technology includes integration of passive components within the plastic array packaging at the component level to minimize the real estate and routing requirements at the PWB level. An example of technology which is further out includes the combination of optical and electronic connections in the structure of the PWB. This paper surveys and describes some of the latest advances and describes potential impacts on spacecraft payload design. The impacts considered are not only the physical impacts, i.e., the change in size and weight, but also the impacts on the design cycle and the supply chain.