Introduction
The study mainly focus on the structures on FCBGA package, the general high speed SerDes signal path on FCBGA package can refer to the Figure 1. The main elements of the signal path consists of the bump and the laser via in die bump area, the trace, the PTH and laser via in PTH area, and the ball. The vertical interconnection structures are refer to the bump+laser via in die bump area and the laser via+PTH+laser via+ball in PTH and ball area. There is another structure structures in advanced package technology, like interposer on 2.5D packaging, but they are not covered by this paper.
Side view of typical high speed differential signal path on fcbga package