Packaging Failure Isolation with Time-Domain Reflectometry (TDR) for Advanced BGA Packages

IC packages become increasingly complex, which make failure analysis (FA) very challenging. This paper presents advanced packaging failure isolation with time-domain reflectometrv (TDR). where the efforts are put on comparative method investigation. Flip-chip ball grid array (fcBGA) and stacked-die low-profile fine-pitch BGA (stacked-die LFBGA) packages are used to demonstrate advanced packaging FA isolation with TDR and good practices in analysis are highlighted, including signature quality improvement and ground selection. The paper also uses software to mimic and observe TDR signature under various failure modes in order to study TDR behavior with different failure modes. The acquired observations are helpful in packaging FA isolation with TDR.