电磁继电器温度冲击失效机理及工艺控制研究

Study on Failure Mechanism and Process Control of Thermal Shock on Electromagnetic Relay

在整机系统试验过程中,温度冲击试验要求20～50个循环,而电磁继电器标准仅要求5个循环,导致常出现温度冲击后继电器失效故障。采用故障树分析和电镜扫描对温度冲击的失效原因进行分析和研究,确定影响温度冲击的原因是镀金触点表面粗糙度及闭合触点压力。为有效控制镀金触点粘接力,首先分析了国内外镀金触点的差异,对镀金触点表面处理工艺进行了优化改进及验证;然后对闭合触点压力相关参数进行DOE试验设计;最终得出了合理的触点表面处理工艺及闭合触点压力的控制方法。研究结果表明,采用研磨处理及振动脉冲镀金的方法,可提升继电器触点表面粗糙度,降低温度冲击下镀金触点表面的粘接力;同时找出合理的控制参数,改善了电磁继电器温度冲击性能,提升了产品质量。

The thermal shock test requires 20 to 50 cycles in the system test process,while the electromagnetic relay general specification requires only 5 cycles,the differences lead to the relay often failure during the test of thermal shock in the system.Electron microscopy scanning and fault tree analysis were used to analyze the causes of failure of relays after thermal shock test,and the conclusion is that the surface roughness of gold plated contacts and the contact pressure of closed contacts are the cause of this problem.In order to effectively control the adhesion of gold plated contacts,this paper analyzes the difference between domestic and foreign gold plated contacts,and verifies the optimized and improved gold plated contact surface treatment process.The design of the pressure related parameters of the closed contact was carried out by DOE experiment method.The reasonable contact surface treatment process and the control method of closed contact pressure were obtained.The results show that the use of SMAT and vibration pulse plating method can improve the relay contact surface roughness,reduce the adhesion of gold plated contact during the test of thermal shock,at the same time,it can find out the reasonable control parameters,which can ultimately improve the relay thermal shock performance and product quality.