Investigating PCB traces for fine pitch applications

Abstract

Surface mounted (SM) components are considered to be dominant in electronics technology. Fine pitch SM components are becoming common due to miniaturization tendencies. Ball Grid Array (BGA) components are classified as fine pitch, if the pitch is 1 mm (39 mil) or smaller [1]. These ICs desire careful approach in Printed Circuit Board (PCB) design. In order to compare the electrical performance of PCBs, two PCB interconnection boards were designed with different wiring patterns for a 650 P Pm pitch commercial BGA. A footprintcompatible dummy BGA was also designed, produced and used to form daisy chain with the PCB patterns. The inductance of the different geometries of the traces on the PCBs and the resistance -varying according to the skin effect at higher frequencies [2] -were calculated and verified by measurements. The skin effect was simulated by Finite Element Method (FEM). The influence of the PCB fabrication deviations was also studied.

Analysis of positioning error and its impact on high frequency properties of differential signal coupler

“…This situation urges for research and development of techniques of high speed interconnections. The goals include ensuring the required bandwidth, electromagnetic compatibility (EMC), as well as the ease of manufacturing with desired transmission quality [16][17][18][19][20]. The growth of transmission rate has direct impact of the interconnect bandwidth inside the device.…”