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…and
PCDs may be revised over time, so material users should use the same material
specification and participate in material specification/PCD change management
activities. Minor deviation from the original process specification is anticipated,
especially for complex parts, but the deviation must be justified by analysis and/or
test, as required…
https://www.wichita.edu/industry_and_defense/NIAR/Documents/NCAMP-DRAM-SOP-202505.pdf