Electro Optical Terahertz Pulse Reflectometry, a non destructive technique to localize defects on various type of package

摘要

Localizing defects (particularly, dead open and resistive open defects) at package level is becoming a critical challenge for Failure Analysis Laboratories due to package miniaturisation and increased complexity. One of the well-known approaches to address this set of problems within a Device Under Test (DUT) is Time Domain Reflectometry (TDR). The main limitation of this technique is the lack of distance-to-defect accuracy and sensitivity. Electro Optical Terahertz Pulse Reflectometry (EOTPR) overcomes these limitations by using photoconductive terahertz generation and detection technology, resulting in a system with: (ⅰ) high measurement bandwidth, (ⅱ) extremely low time base jitter, and (ⅲ) high time base accuracy and range with greater sensitivity. In this paper we present case studies in which EOTPR has been successfully applied to a series of different device types.