Fall 1992
Capability Analysis & Statistical Process Control Applied to Photochemical Machining
Using the concepts of Cp and CPk this paper demonstrates, with
the aid of worked examples, that Capability Analysis may be
usefully applied to PCM. It is shown that the Capability Index, for
any stage of the process, may be calculated from the process data
and compared to the “target” values. The variation of the Index
with process mean levels, standard deviation and specification
limits is clearly shown. In part 2, Statistical Process Control, as
applied to the etching process will be considered in depth and the
derivation of control limits discussed.
Richard Allen, Attewell Ltd.
