An optimization method of ultra hign speed differential structure for BGA package

With the advent of the 5G era, the clock frequency continues to increase, and the system's requirements for signal transmission rates are getting higher and higner. High frequency and high speed chip technology is developing vigorously, and the demand for hign frequency and high speed packaging enclosures to match it is strong. Among them, the BGA package structure is favored by people due to its advantages such as high density and miniaturization. However, the impedance control introduced by the vertical interconnect holes and BGA balls in the ultra high speed BGA package structure has brought serious problems to the signal integrity. How to solve the mismatch problem of the differential pair in the ultra high speed BGA package is the key. This article provides an optimization method for the differential structure of an ultra high speed BGA package, through vertical via impedance adjustment technology, BGA ball matching compensation technology, etc. To achieve impedance matching and reduce loss. It is the earliest to realize ultra high speed differential BGA transmission within 50GHz bandwidth, with less than 1.8dB the difference loss, greater than the return loss, and the theoretical maximum transmission rate of 100Gbps.