Testing Method: Backdrill Defect Detection

Backdrill is the process of creating vias in multilayered printed wiring boards to allow signals to flow from one layer of the board to another. Backdrilling is performed as a finishing step in the manufacturing process of PWBs. Proper back drill length is a critical component for manufacturers to minimize signal integrity issues in printed wiring boards. Unfortunately ensuring the drilling is done accurately has proved difficult to measure after the fact. Several methods such as sophisticated as optical analysis or as simple as placing a “stopper” on the drill bit have all had shortcomings.

With experience in measuring insertion and return loss with TDR measurement systems,  Introbotix has recently developed a method of measuring stub length to a useful resolution.


The industry’s first high-resolution stub measurement for production environments.