电连接器热循环加速试验与失效分析研究

Accelerated Thermal Cycling Test and Failure Analysis of Electrical Connectors

空间技术的迅猛发展对电连接器可靠性提出了更高的要求,主要研究温度循环条件下电连接器的可靠性问题。结合加速寿命试验理论,设计了一种电连接器热循环加速试验方案并进行了试验。在试验中,试品接触件的接触电阻值随循环次数的增加而缓慢增长,利用灰色模型预测出了试品的热循环寿命。此外,对试验后试品插孔的分析发现:插孔的晶粒尺寸增大且不均匀,亚结构的碎化程度、位错密度及有序的β'相均有增加。由此可知,连接器插孔中微观结构的变化是引发其综合力学性能下降,插孔出现应力松弛现象,而导致接触可靠性逐步蜕化的根本原因。

The rapid development of space technology has put forward higher requirements for electrical connector reliability. The reliability issues of electrical connectors under thermal cycling conditions are presented. A thermal cycling test scheme combined with the accelerated life test theory is proposed for electrical connectors. The accelerated thermal cycling test is carried out. It is found that the value of contact resistance increases slowly with the number of thermal cycles. The extrapolated value of thermal cycling life is calculated by gray model. Finally,the failure analysis on the jack of typical samples is illustrated. It is indicated that the crystal size rises,the fragmentation degree of the sub structure and the dislocation density increase,and there is more β＇phase appearing in the jack of samples after test. The result shows that the change of microstructure is the fundamental reason for the stress relaxation phenomenon of jacks and the contact reliability degradation of electrical connectors.