Characterization of flip-chip interconnects up to millimeter-wave frequencies based on a nondestructive in situ approach

In this paper, the performance of flip-chip interconnects at frequencies up to 40 GHz is presented based on a nondestructive in situ measurement approach. The method unfolds the raw flip-chip interconnect excluding any launch structures in concomitance of a mounted silicon chip. The results are compared with a commonly used two-port through measurement technique of coplanar wave (CPW)-to-CPW transitions without involvement of a silicon chip. Finally, the attempt has been made to extract the electrical performance from a directly probed flip-chip interconnect for the first time.