Statistical design techniques for high-speed circuit boards with correlated structure distributions

Statistical design techniques for the line structures of high-speed circuit boards have been developed. These techniques account for dimensional distribution correlations caused by the fabrication process. Monte Carlo simulation is introduced into the finite element method for calculating line parameters. The eye pattern at the receiving end of transmission lines with parallel and stub parts is simulated, using distributed circuit modes, for the calculated line parameter distributions. The simulator has an algorithm to save computer time. The calculated and experimental results are compared, and the accuracy of the simulation is discussed. Calculation results imply that the evaluation for the dimensional distribution of fabrication processes is very important. The timing and amplitude margins were found to strongly depend on fabrication deviations