Cadence PCB Best Practices

Working with Backdrilling Backdrilling October 2019 29 Product Version 17.4-2019 © 1999-2020 All Rights Reserved. Once analysis runs the number of Plunges (backdrill candidates) are generated. Tip Backdrill layer pairs can be excluded from the backdrill process under the Enable column. Backdrill candidates on disabled or missing layer pairs will be reported as backdrill errors (stub violations) in the report and generate a canvas Flag Code figure. Disabling underutilized layer pairs to isolate the backdrill plunges location that need to be reviewed and to possibly eliminate the layer pair after some routing tweaks.

• 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