Working with Backdrilling in Allegro PCB Designer: Best Practices
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Tool Tip – Develop a plan to incorporate the following properties at the library level:
• BACKDRILL_MIN_PIN_PTH
• BACKDRILL_PRESSFIT_CONNECTOR
• BACKDRILL_EXCLUDE
User Overrides
In most cases, the backdrill layer ranges defined in the Backdrill Setup and Analysis
user interface will satisfy your requirements to manage stubs. The
BACKDRILL_OVERRIDE property has been provided to allow user-specified control of
layer ranges for any pin or via and from either side of the board or both. This is done
regardless of violations that might result (such as testpoint conflicts or backdrilling
through a connection). The override property was considered for the design of test
coupons where the OEM wishes to evaluate the performance of the board fabricator
with respect to the adherence of depth ranges. The Designer may override the "to" layer
to effectively drill out the layer where the trace connects the pin/via. The expected
usage of this property is limited.
Note: Exercise caution to prevent accidental over-drilling.
Property
BACKDRILL_OVERRIDE
Purpose
User-specified backdrill range
Usage
Optional – special circumstances
Value
TOP::BOTTOM:
Objects
Symbols, Pins, Vias
Backdrill analysis flag
O W
OR
