印制板局部电镀金悬边问题的研究

文章重点阐述了局部电金板镍金悬边过大和悬边断裂的原因分析和改善方案,并运用电化学原理和金属腐蚀学的理论解释这种想象的产生成因,做到理论和实际相结合。蚀刻悬边过大主要与排风量大小(O_(2)供应)、蚀刻喷淋压力、氯离子含量有关;悬边断裂主要与Ni、Cu、Au三种金属在退锡液中发生的原电池腐蚀有关,同时退锡液中的护铜剂又影响了原电池腐蚀的位置与进程;最后也提出了另一种避免蚀刻悬边的方案。

局部电镍金板工艺优化研究

局部电镍金的板件主要应用场景有邦定、长时间摩擦接触、插拔等,如:光模块、晶圆测试、存储卡、测试卡等领域都有大量应用,为满足上述特殊应用场景要求,局部电镍金设计的板件越来越多,此类板件制作流程长、制作难度大,在制作过程中,特别是一些局部电镍金焊盘面积小、间距小、位置孤立的,更是容易出现如:渗金、电镍金参数控制不当导致蚀刻时电镍金位置线路开路等问题,需在制作过程中涉及方法、材料、时效控制等多方面精准控制,对PCB厂的加工控制提出了极大的挑战,本文对上述失效的问题进行了详尽分析,提出了控制方案供同行参考。

Partial Discharge Simulations Used for the Design of a Non-Intrusive Cable Condition Monitoring Technique

The purpose of this paper is to investigate the effect of PD （partial discharge） activity within medium voltage XLPE （cross-linked polyethylene） cables. The effect of partial discharge was studied by means of a number of simulations. The simulations were based on the well-known three capacitor model for partial discharge. An equivalent circuit was derived for partial discharge due to a single void in the insulation material of a power cable. The results obtained from the simulations will form the basis of the design proses of a non-intrusive condition monitoring technique. The technique is based on the classification of discharge activity according to five levels of PD. Future work will include the improvement of the simulation model by investigating the high frequency model of a power cable as well as the statistical nature of PD activity. This will improve the accuracy of the simulation results when compared to actual measurements. The work discussed in this paper will be used to construct and calibrate a practical model which will make use of PD measurements for non-intrusive condition monitoring of medium voltage electrical cables.