Testpoint Clearance Check (New Feature Summary)
This document is no longer available beyond version 15.1. Information can now be found here: Fabrication and Assembly Testpoint Style Rule for version 25
The ability to configure any pad or via to function as a testpoint is a valuable feature used during bare-board fabrication testing, and also during the assembly process. Bare-board flying-probe testing allows the fabricator to quickly test between each testpoint and every solder-exposed thru-hole pad and via on the board - delivering an extremely comprehensive test of positive net connectivity, and shorts.
A challenge with bare-board flying-probe testing has been the need to ensure that each testpoint maintains a minimum center-to-center clearance from adjacent pads and vias - otherwise the size of the flying-probe heads can prevent the testpoint and the neighboring pad/via from being simultaneously contacted.
Configuring the Testpoint to Pad/Via Hole Center Distance
The minimum allowable distance from the center of a testpoint to the center of an adjacent pad/via is defined in the Fabrication Testpoint Style or the Assembly Testpoint Style design rules in the PCB Rules and Constraint Editor dialog, as shown below.