Vector vs. Vectorless ICT Test Techniques

摘要

Over the last decade, there has been a move away from powered-up digital in-circuit vector testing to unpowered analog-based (vectorless) device-pin opens testing for large and sometimes small digital devices. Two of the driving factors behind this move are the increasingly complex and custom design of digital devices that are being used and the limited digital in-circuit test (ICT) capabilities of most ICT systems. Most ICT systems on the market today simply do not have the timing and voltage accuracies required to reliably and safely test today's generation of low-voltage, high-speed digital components. At the same time, analog vectorless measurement techniques that can be used to detect open pins have become more acceptable and widespread. The introduction of active capacitive probes and advanced software algorithms has made the open-pin defect detection provided by these techniques acceptable to most manufacturers. ICT program developers also lack the digital device models required to perform digital vector testing, and they do not have the time required to write digital vector models for complex devices.