Leadless 432-pin package and solderless socket used in a system operating with a 622 MHz digital clock

This paper presents the electrical, thermal, and system performance of a leadless MCM-D electronic package with a 432-pin land-grid I/O array. The package is mountable/demountable to its printed circuit board by means of a solderless socket. Custom designs are used for the package and its socket, but both are built with commercially available technology. The package is used to house a single GaAs gate array that operates with a 622 MHz digital clock and that communicates to its circuit pack both with 622 Mb/s ECL-level signals and 78 Mb/s TTL-level signals. To support these high-speed signals, the package includes controlled impedance striplines, thin-film resistors, and microwave-quality decoupling capacitors. With the use of standard forced-air cooling and an external heat sink, the package can dissipate up to 25 W of power.