An improved three-dimensional (3-D) scheme for modular packaging and interconnection of electronic circuits has been proposed to overcome deficiencies of an older scheme and to obtain additional advantages. In particular:
- The older scheme includes elastomer-based interconnections that fail at temperatures below –53 °C. The interconnections in the proposed scheme could function at temperatures from cryogenic to 200 °C.
- In the older scheme, it is necessary to disassemble an entire module in order to insert or remove individual submodules called "slices." In the proposed scheme, individual slices could be inserted or removed without disassembly of an entire module.
- The proposed scheme provides for better thermal management.
- In the older scheme, the capability for expansion is limited. The proposed scheme would provide versatility for integration of modules into systems, for integration of systems with each other, for expanding systems, and for configuring systems for testing.
An essential part of the scheme is to construct an electronic system with a common modular design for all subsystems. The figure illustrates selected aspects of the proposed scheme as applied to a four-slice module. Each slice would include electronic circuitry held in a supporting frame, which would contain the features needed for mechanical, electrical, and thermal connections to support insertion, removal, expansion, testing, and integration. Optionally, one could use external or internal input/output interfaces. Also, optionally, one could incorporate thermal insulation between slices or between modules.
Slices would be mechanically connected to adjacent slices via guide pins and retainers that would mate in the manner of plugs and sockets. Once the guide pins were inserted in the retainers, setscrews would be tightened to push on slanted guide-pin surfaces to generate contact forces. In a module oriented as in the figure, the contact forces between slices would be horizontal. The thermal path for each slice could be vertical and directly into a heat sink if the slice were bolted down onto the heat sink via the boltholes on the flange of its supporting frame.
This work was done by Don Hunter of Caltech for NASA's Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free on-line at www.nasatech.com/tsp under the Electronic Components and Systems category. NPO-20362