氢还原反应过程监测- MKS Cirrus 2

PROBLEM: A major manufacturer of TV and Computer CRT monitors experienced an outbreak of mis-processed components caused by equipment failure. The problem occurred in a thermal reduction process used in the production of nickel caps for thermionic emission cathodes, which are used in electron gun assemblies. The cause of the problem was quickly isolated to contamination of the high purity hydrogen supply to the reduction vessel with nitrogen, causing nitrides to form on the cap surface. The nitrides interfered with the critical interface between the cap nickel and the emission determining spray layer, causing failures at predelivery testing of the cathodes. The equipment was modified and short term control measures were put in place to ensure detection if the problem reappeared. However, the control measures required expensive offline scientific analysis using LAICPMS to be performed after every reduction cycle on a sample of caps, and so a more cost effective real-time solution was desired without an increase in risk to the component quality.