简介: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 productio简介: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.详细>