Packaging means different things to different people. For a device designer, it is an enclosure of almost microscopic size. For a systems-level engineer, it may be a series of racks that must fight on a battleship. No matter the size, electronic packaging is meant to provide mechanical protection while remaining electrically invisible.
When factors such as high production volumes come into play, then packaging goals must also be met with cost constraints. At the other extreme, electronic packaging for devices heading into outer space, such as on satellites, must endure temperature extremes and vacuum environments. Packaging is often taken for granted as part of an integrated-circuit (IC) design process, but the reliability and successful operation of that IC usually hinge on the quality of its package.
Higher-frequency packages must be considered as part of the circuits they enclose. For example, semiconductor die are typically either fully encapsulated in some form of epoxy-based compound, or else they are mounted in some form of cavity package formed of different materials (including metals, ceramic, and plastic).