Reverse Engineering Printed Circuit Board

Reverse Engineering Printed Circuit Board can improved accuracy propagation delay measurements and can be completed with the TDR used in TDT mode. In TDT mode, probes are placed at each end of the test structure. A pulse is generated from one end and captured at the other.

This causes less edge rate degradation than the simpler TDR approach, which results in improved accuracy by through PCB reverse engineering. Real results should only be completed with microprobes. A proper setup can achieve within +/- 2 ps/in accuracy.

Traces should follow the guidelines described for impedance coupons in section 3.1.1. Measurement structures are defined in pairs for each signal layer which differ only in length. The recommended minimum trace lengths are listed below, and are based on time for pulse to settle. This settling time can vary depending on the impedance of the trace before Printed Circuit Board polygons reverse engineering.

Stripline structures for use with microprobes should have a via escape at each end to route external traces for probing. The via size should be no larger than a 25 mil pad with -10 mil finished hole.


Tags: ,,,,,,,,,,