Risks for Signal Integrity in System in Package and Possible Remedies

We analyze the electrical phenomena that can affect the integrity of the communication among different chips within a System in Package (SiP). We address these issues for a real case, for which electrical parameters are extracted from layout and used to build a netlist employed for electrical characterization. We show that crosstalk, and in particular inductive crosstalk, is the electrical phenomenon mainly affecting signal transmission within the SiP. Then, we evaluate the kinds of errors that can be originated. We show that errors caused by inductive coupling among SiP interconnects can be unidirectional only, thus allowing designers to implement error control coding techniques based on All Unidirectional Error Detecting codes. This allows significant cost reduction over the alternate use of non-unidirectional error detecting codes.