Abstract: The chip-to-board (or chip-to-MCM) connection assembly and method therefor features a semiconductor chip (31) having a front surface (31f) on which external terminal pads are provided; a board or MCM (32) having a surface (e.g., a recessed surface) at a first side thereof to which the rear surface (31r) of the chip is affixed; and a connection carrier (33), disposed as an overlay, which electrically links the chip and the board or MCM. In this assembly scheme, the connection carrier (e.g., a bump carrier) which is affixed to both the chip and the board or MCM, contains all required signal line tracings (57) to provide the electrical interconnection between the semiconductor chip and the board or MCM. The bump carrier replaces all bond wires (24) and the like and can include support/control circuitry, passive and/or active, associated with, for example, high-speed/high-power IC chips (51).

Abstract: A spacecraft (10) having a cryogenic cooler (24) that maintains different temperatures in thermally insulated and nested enclosures (26, 28, 12). In the coldest enclosure (26), which is maintained, for example, approximately 10.degree. K, low-temperature superconducting (LTS) processors (32, 34) perform bus and payload processing functions at very high speed. The next-coldest enclosure (28) is maintained at approximately 77.degree. K and houses high-temperature superconducting (HTS) electronic modules, such as for power regulation and distribution (40) and a payload sensor processing module (38). The third of the enclosures (12) is maintained at approximately 300.degree. K and houses other modules operating at room temperature, including a transponder (44), power control (46), energy storage (48), a propulsion subsystem (22), a downlink data processing module (49) and the cryogenic cooler (24) itself.