Hello everyone,

I have a question about the minimum standard fabrication allowance for connection pads according to the IPC-2221B standard.

In the copy of the standard I have, Table 9-1 (Minimum Standard Manufacturing Tolerances for Connection Pads) contains the following values:
Level A: 0.40mm
Level B: 0.25mm
Level C: 0.20mm

However, I notice that many websites online ref
er to Table 9-1 of the same standard as having the following values:
Level A: 0.6mm
Level B: 0.5mm
Level C: 0.4mm

Can someone resolve this contradiction? Are the values listed on most websites out-of-date? Or has the standard been updated since the copy I have? I have the copy updated in 2012.

Thank you in advance,
Elizabeth