Electronic Packaging Techniques in the Mars Observer Camera

Volume constraints of small spacecraft place difficult packaging requirements on electronic designs. High component counts per unit area and stiff, lightweight boards with large surface to volume ratios will define the state of the art for PWB assemblies. The Mars Observer Camera, a high resolution imager on the Mars Observer mission, required innovative developments in these design areas to satisfy the difficult volume constraints placed on the instrument. These included qualifying a high-reliability "I-lead" surface mount technique used throughout the electronic system. This enabled a density with 4500 parts (including large DIPs and flatpacks), boards, and cabling in 900 cubic inches and a 14 inch diameter PWB/honeycomb board design. These PWBs were mounted through low frequency vibration isolators which provided dynamic and thermal strain isolation. This paper outlines the specific technical achievements gained with the Mars Observer Camera packaging design and the many design rules developed from it.