手机中振子连接器的失效分析

Analysis on Failed Vibrator Connectors in Mobile Phones

研究了手机中失效振子连接器镀金触点后发现,接触表面污染、连接器制造及表面镀层材料缺陷是造成电接触故障的主要原因。表面污染物来自于尘土颗粒和微动磨损,主要集中在印制电路板(PCB)一侧,其成分包括C、O、S i、A l、S、C l、Na、N i等多种元素。测试结果表明,污染表面多达86%的测量点的接触电阻超过设计标准。随后通过有限元建立振子连接器模型进行模态分析,结果表明连接器固有频率与其工作振动频率相接近,容易引起触点接触正压力的降低和磨损加速,降低了振子连接器的接触可靠性。

The contamination on contact interfaces and default of plated material and manufacturing were found to be the main reasons to cause electric contact failure by analyzing gold plated contacts of vibrator connectors in failed mobile phones. The contaminants are from the dust in environment and fretting debris, and mainly concentrated on the contacts on printed circuit boards. The element compositions of contaminants include C, O, Si, Al, S, Cl, Na, Ni etc. 86 % of the contact resistance tested on contact zones was higher than the design limitation. Frequency analysis was carried on by building the simulated vibrator connector model, the result showed that natural frequency of connector was approached to the driver frequency, which caused increase of fretting and decrease of contact normal force, and as a result, made the contact reliability degraded.