EOTPR Fine Pitch Probing for Die-to-Die Interconnect Failure Analysis

Abstract Debug and physical failure analysis (PFA) of heterogeneously integrated semiconductor packages, particularly die-to-die (D2D) input/output (I/O) type fails, has become very challenging due to the lack of direct access to the I/Os from the package substrate to do static open/shorts fault isolation and limited test program granularity to determine which location along the D2D interconnect trace is failing. Thus, a suitable electrical fault isolation technique is required to ensure high success rate for root cause analysis. This paper discusses how EOTPR is used to isolate defects on a D2D interconnect trace of a chiplet advanced packaging using local silicon bridge with reasonable accuracy. Minimal sample preparation was needed to expose the I/O bumps for probing, thus minimizing the risk of artifacts that may cause the defect to be lost. A case study will demonstrate the successful application of the technique.