Failure isolation for advanced packages using time-domain reflectometry

Failure analysis (FA) of integrated circuit (IC) packages is critical to deliver IC products with good quality. With IC packages being increasingly complex, FA becomes much more challenging than early days. This paper presents failure isolation for advanced packaging using time-domain reflectometry (TDR). One case of ball grid array (BGA) is introduced to demonstrate the utilization of TDR FA in UTAC. Flip-chip BGA (fcBGA) is the other focus of this paper, especially the package with small body size and short signal transmission path. TDR results that could give engineers misleading information are discussed. Software simulation is utilized to assist the fault isolation. It´s shown to be an excellent way to locate the failure spot accurately.