Inner‐layer Registration Testing System

Abstract

Using a patented measuring technique, the perfecTest system has the ability to give a quantified and accurate measurement down to 25 micron (one mil) for any directional X‐axis and/or Y‐axis inner‐layer shift. Individual inner layers can be distinguished from each other and reviewed in either tabular or graphic format. Control limits are set within the software to provide pass/fail testing and all testing is performed in real time. With functions such as data storage, retrieval and SPC analysis, the system is a very powerful tool to monitor and manage inner‐layer registration problems and can lead the way to improved yield and reliability instead of creating more waste. Hole break‐out is the main cause of intermittent failure in PCBs. As the result of through‐hole plating, there is conductivity along the drill‐hole barrel. PCBs having such severe registration problems will pass in‐circuit and bare‐board tests. However, intermittent failure is often not detected until the product reaches the field and is in use.

Citation

Siddons, D. (1993), "Inner‐layer Registration Testing System", Circuit World, Vol. 19 No. 3, pp. 54-58. https://doi.org/10.1108/eb046214