Ruggedized PC/104-Plus PowerPC Processor card for avionics

A ruggedized PowerPC Processor card was designed to meet a PC/104-Plus form factor. Because this card was designed to be a generic "motherboard" for many applications, the PC/104-Plus form factor was chosen for its small size, enabling this board to be used almost anywhere. The PowerPC was chosen as the processor for its wide use in the industry, the large number of supporting COTS (Commercial Off The Shelf) development tools, significant processor throughput, and a direct replacement to a radiation tolerant part. The small board size required some innovative packaging techniques: micro-via technology, many signal layers and board material. This caused the board thickness to exceed the recommended form-factor, but longer pins in the thru connectors as well as Arlon Thermount for the board aided in rectifying the problem. A combination of board thickness, frame support and component selection were used to meet the acceleration load requirements. Processors running at high speeds tend to dissipate large amounts of heat. To remove the heat from the board, the side frames once again were called into use. The board is designed to operate in a standard convection cooled environment. An additional connector was added to the board to provide a high-speed local bus connection to a reconfigurable input/output(I/O) card, as well as to a PCI (Peripheral Component Interconnect) interface. Providing these two interface mechanisms to I/O cards allow COTS PCI cards to be utilized, in addition to our high-speed custom reconfigurable I/O card. This flexible architecture allows the I/O demands of almost any system to be met.