High performance package designs for a 1 GHz microprocessor

This paper describes the architecture and design of an organic land grid array (OLGA) and a flip chip pin grid array (FCPGA) package for a 32 b microprocessor with a clock frequency of 1 GHz and an I/O bus designed to run at 133 MHz. Cost and performance targets and compatibility with existing systems are the key accomplishments of this design project. Issues and implementation details of each of these aspects are discussed and contrasted here. This paper concentrates on the processor performance issues associated with the package routing and power delivery. To overcome high inductance associated with the socket and package pins in the FCPGA package, decoupling capacitors were placed on the underside of the package substrate. This paper discusses an optimal placement scheme for the capacitors and their effectiveness in performance improvement of the system compared to the OLGA package case