Working with Backdrilling in Allegro PCB Designer: Best Practices
Learn more at Cadence Online Support https://support.cadence.com
© 2014 Cadence Design Systems, Inc. All rights reserved worldwide.
Page 35
Manufacturing Stub Length Analysis (Drill Parameters
Tab)
There is an advanced setup for Backdrill and Analysis to verify that the remaining stub
length after backdrill is manufacturable by specifying a manufacturing stub length. This
is a value driven by the fabrication vendor and should not be confused with the
minimum Electrical Stub requirements defined using the BACKDRILL_MAX_PTH_STUB
Property. Essentially, it is the remaining stub that can be reliably manufactured without
comprising the Must Not Cut Layer.
The manufacturing stub length value will default to 0.00, which disables the advanced
analysis and reporting. Entering the stub value provided by the fabricator will turn on
the advanced analysis and layer pair violation reporting to influence your backdrill
decisions. This value will be reported in the Backdrill Analysis log file and Backdrill Drill
Legends.
