Hi,
As I confirmed the JESD 201 standard,
"Table 4b - Manufacturing Process Change Acceptance Tests and Durations"
I think that they apply "Table 4b" rather than "Table 4a - Technology Acceptance Tests and Durations"?
* Using Manufacturing Process Change Acceptance or Technology Acceptance
Whether to use or not is defined in Table 1 below.
If you change the lead frame material, use Table 4a instead of Table 4b
I do not know why Table 4b is used.
Best regards,
Seishin