Signal integrity design and validation for multi-GHz differential channels in SiP packaging system with eye diagram parameters

Differential interconnect lines in multi-gigabits system in package (SiP) packaging system are studied in this paper. The performance of interconnect lines can be easily estimated with jitter and eye opening using the eye diagram that is very helpful metric. To maintain good eye-diagram with high voltage swing and low timing jitter, a signal integrity (SI) design flow of SiP is proposed based on eye-diagram parameters. To validate the influences of SI design to eye-diagrams, the relationship between the parameters of eye diagram and the structures of the impedance discontinuities physical elements such as vias, SMT pads are studied by a combination of software simulation and hardware validation. Some SI design rules are stipulated. As an example, a 4-channel × 10 Gbp/s/channel optical transceiver in an SiP package is designed.