TDR Testing

Signal Analysis

As the signal propagates along the conductor, any change in trace width, copper thickness, or dielectric spacing causes a change in local impedance, which reflects a portion of the energy back to the source. The test instrument records these reflections as a function of time, translating the temporal data into physical distance along the trace. This profile allows technicians to identify the exact location of defects such as trace neckdowns, solder shorts, or internal layer misalignment.

By checking these impedance traces, fabricators ensure that the board will handle high-frequency signals without distortion. Reliable signals prevent data loss.

Quality Standard

Industry standards such as IPC-2141 specify the acceptable limits for impedance variation, which is typically five to ten percent of the nominal value. Test logs must be archived for high-reliability applications. Proper calibration of the test probes ensures repeatable results.

Compliance with these standards guarantees signal integrity.