Research On The Effects Of Insertion-extraction On The Storage Life Of Electrical Connector Contacts

Life assessments and prolongations of some equipment have a great significance. Life assessment of electrical connectors is the premise on life assessment of equipment, because electrical connector is a basic electromechanical component which is used to transfer power and signal. At present, the main work is to investigate the influence of temperature. However, the insertion-extraction was not taken into account, which can not fully reflect the actual stress state of electrical connectors during storage, making the assessment result inaccurate to guide engineering evaluation. The dissertation took the Y11P-1419 electrical connector as the object, used the combination method of failure analysis and experimental investigation to reveal the effects of insertion-extraction and mates on storage electrical connector. And, the experiment combined test data to evaluate the quantitative life differences of insertion-extraction and mating. Furthermore, the paper put forward the proposal to engineering applications, which offers theoretical support and practice guidance for the storage life evaluation.The main contents are as follows:1.This part elaborated the background and significance of the study, summarized the research status at home and abroad of evaluation on storage life and the development history of accelerated test. According to the research status at home and abroad, the paper pointed out the insufficiency of the storage life evaluation on electrical connectors as well as raises the research objects and main contents.2.This part concluded the category and the major feature of common electrical connectors based on the usage and the functional demands of the electrical connectors on equipment, and gave analysis on the model storage, storage stresses and failure modes when the Y11P-1419 electrical connector was stored. And from the level of failure mechanism, revealed the effect of insertion-extraction on storage electrical connectors: insertion-extraction leads to resistance hopping, wipes gold layer and film, accelerates oxide etch during subsequent storage.3.This part designed an accelerated degradation control test to confirm the phenomenon of resistance hopping after insertion-extraction, also conducts additional tests, and got the time to restore stability of contacts. Using the non-parametric test methods to determine the experimental data showed that the insertion-extraction on electrical connector accelerated degradation rate. Further more analyzed the microscopic surface of test samples by SEM and EDS, which verified the failure mechanism of insertion-extraction.4. This part established a mathematical model of contact resistance which contains microscopic factor by electric potential changes and electrical contact theory. Considering the creep and stress relaxation of contacts during long-term storage, the degradation model of contact resistance was set up. With the regression analysis and the least squares method estimated the model parameters. Based on the test data, the experiment got the track of performance degradation under 120℃, and accelerated 22.81% on the failure life of contacts after considering insertion-extraction.5.This part summarized the main research contents of the text, and prospected further research work.