Diagnostic of Connector's Degradation Level by Frequency Domain Reflectometry

Abstract

International audienceBecause of the increasing size of electrical networks in automotives, the degradation of wires and connectors has become a major concern. As a matter of fact, severe system failures are often merely due to broken wires, bad crimping or degraded connectors. Furthermore, the difficulty to localize those kinds of defects using nowadays techniques generally leads to costly repair. Reflectometry is a well-known method used to monitor the health of lines and wired networks. Wiring networks can be affected with two types of faults: "soft ones" are created by the change of the impedance along the line due to different kinds of defects (insulation, radial crack, and degradation of connector...) in the wire and "hard ones" which correspond to open and short circuits. For the first type of faults, the frequency-domain response of the faulty wiring presents a modification of the impedance, in the defect location. For that reason, this paper focuses on the application of the reflectometry technique to the broadband characterization of a vibration degraded Cu-Sn connector. Once the Sn plating is removed, the electrical properties of the contact interface are entirely modified. The results presented in this paper show that observing such kind of transition can be used as criteria for estimating the degradation level of the connector

Experimental Validation of the Inverse Scattering Method for Distributed Characteristic Impedance Estimation

“…These methods are based on the same principle as radar technology, but applied to guided waves in electric cables. A high-frequency electrical signal is sent down a cable, where it is reflected at impedance discontinuities or at other Manuscript [15]; but, except for connectors [9], to our knowledge, no satisfactory experimental result of reflectometry-based method for the diagnosis of such soft faults has been reported. The characteristic impedance Z 0 is the main parameter characterizing an electric cable.…”

“…9, the connector's location and the impedance variation caused by the connector can be inspected by the inverse scattering method. It is then possible to elaborate some diagnosis rules of the connector based on the evolution of the estimated impedance profile over the time [9].…”

“…Many diagnosis methods based on time or frequency domain reflectometry (TDR or FDR) have been developed to detect, locate, and characterize defects in electrical harnesses [2]- [9]. These methods are based on the same principle as radar technology, but applied to guided waves in electric cables.…”

A Digital On-Line Monitor for Detecting Intermittent Resistance Faults at Board Level

“…Several methods have been used traditionally for testing interconnects at the board level such as DC resistance measurements, 6 radio-frequency (RF) impedance analysis 7,8 Built-in Self-Test (BIST) 9 and analog neural network technology. 10 DC resistance measurements 6 is a useful method to detect stuck-at short, stuck-at open and bridge faults in interconnections at test mode.…”

Wire Troubleshooting and Diagnosis: Review and Perspectives

“…In [70], broadband FDR is used to track the degradation in a vibrating Cu-Sn automotive connector. The aging of the contact, due to the progressive removal of the tin plating, changes its local impedance which can be measured using FDR.…”