高密度混装印制板组件力学特性研究

Study on Vibration Characters of Mixed PCBs Soldered with Lead and Lead-free Solders

为研究某回流焊工艺后有铅无铅混装印制板组件的振动可靠性,采用实验EAM方法验证有限元ANSYS分析印制板组件振动特性的准确性,进一步探索影响印制板组件动态性能的因素,最后通过随机振动环境仿真分析该回流焊工艺的合理性。结果表明:有限元ANSYS能正确描述印制板组件的动态特性,与实验EAM模态分析结果相差8.3%;低阶频率对应的振动极值和振动方向数目少,随频率增大,振型方向逐渐变得紊乱而没有规律;决定印制板组件动态特性最重要的参数是印制板大小;通过随机振动分析表明该回流焊工艺曲线参数设置合理。

To study the vibration reliability of mixed pcb assemblies soldered with lead and lead-free solders after SMT technology,test the correction of the ANSYS analysis based on the EAM experiment,further explore the factors affecting the dynamic performance of PCBs,finally,the rationality of the reflow soldering process is analyzed by random vibration environment simulation. The results show： the finite analysis could be used to predict the PCB vibration,which is 8.3 percent different from the EAM experiment; The low order frequency corresponds to a small number of vibration extremum and vibration direction,with the increasing of frequency,the vibration becomes disordered and irregular; The most important parameter to determine the dynamic characteristics of PCBs is the size of PCB; The analysis of random vibration shows that the parameters of the reflow soldering process are reasonable.