Cadence PCB Best Practices

Working with Backdrilling Backdrilling October 2019 50 Product Version 17.4-2019 © 1999-2020 All Rights Reserved. Enabling Backdrill Output The output of backdrill data is controlled by the parameter Include backdrill which is available in both the NC Drill and NC Legend forms. Figure 1-23 NC Drill dialog NC Backdrill Legends Similar to the standard NC Legend, the backdrill legend provides a symbolic representation of the sites to be backdrilled. The legend table lists oversized backdrill sizes used during the backdrill process.

• Cover
• Contents
• Backdrilling
• Introduction
• Licensing
• Prerequisites
• Backdrill Commands, Properties, Parameters, and Subclasses
• Terminology
• Net Identification
• Applying the BACKDRILL_MAX_PTH_STUB Property in Constraint Manager
• Stub Calculation
• Pin Plating Restrictions
• Applying the Minimum Pin Plating Property
• Pressfit Connectors
• Backdrill Exclusions
• User Overrides
• Fabrication Vendor Backdrill requirements (Reference Only)
• Setup and Analysis User Interface
• Initially Launching the Backdrill Setup and Analysis Dialog Box
• Prior to executing Backdrill
• Padstack Parameters Tab of the Backdrill Setup and Analysis Form
• Flag Codes tab of the Backdrill Setup and Analysis form
• Final Backdrill Steps – Executing Backdrill
• Manufacturing Stub Length Analysis (Drill Parameters Tab)
• Effects of Setting a Manufacturing Stub Length:
• Layer Pairs tab feedback – Depth column yellow cells:
• Backdrill Canvas Display Controls
• Backdrill Data Show Element visibility (Pins/Vias)
• DRC and Shape Voiding
• Board Testability
• NC Drill and Legend Output
• Enabling Backdrill Output
• NC Backdrill Legends
• Legend Customization
• Backdrill Cross Section Chart Display