Cadence PCB Best Practices

Working with Backdrilling Backdrilling October 2019 45 Product Version 17.4-2019 © 1999-2020 All Rights Reserved. Backdrill Data Show Element visibility (Pins/Vias) Backdrill data is reported on pins/vias at the bottom of the show element information window. DRC and Shape Voiding Internal design layers have route keepout shapes generated using the BACKDRILL_CLEARANCE KEEP OUT geometry definition in the padstack to maintain clearance from the backdrill hole to all copper features. Negative planes utilize BACKDRILL_CLEARANCE ANTI PAD definition in the padstack to maintain clearance to backdrill.

• 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