Fine-line printed circuit board for high-performance computer design

Properties of a new fine-line printed circuit board which are critical in the design of computer systems based on GaAs, 100 K and 10 K logic families, are characterized. The new PCB technology permits trace widths as fine as 0.002 in. on the inner layers of multilayer boards. While facilitating higher package density and controlled impedance interconnects with higher characteristic impedance (Z₀ ), the technology opens questions of thermal reliability, ohmic heating, and noise margin. Cross-validating analytic and laboratory analysis is used to investigate each of these issues. Provided that several key issues are addressed during design, this report supports the use of 0.002 in. technology in high-performance computer systems