The Parameter Optimization Of Applied Of FPC Manufacture And Application

The development direction of Printed circuit board is "light, thin, short and small".The modern electronic products packaging trend of functional direction,miniaturization, high speed and high density put forward higher request to PCB（Printed circuit boards） industry. Flexible printed circuit board can deflect underdynamic and static condition, and have the characteristics of light, thin, and well heatdissipation,FPC(flexible printed circuit board) also can provide more I/O interface forthe electronic equipment. That’s why FPC got be widely used and has become the mostactivity and development prospects of PCB industry.In this paper, the main manufacture process of FPC is described, including fineline processing, blind hole processing and the thermal expansion controlling processingin rigid-flex board. We also conclude the main failure behavior caused by thosemanufacture. Finally, the failure mode of PCBA under different temperature is beenstudied.The study of fine line manufacturing and failure behavior is based on thetechnological equipment of bo min electronics co., LTD. The experiment arranged byorthogonal experiment method, after range analysis of the results of experiment,theoptimum value of fine line parameters is as follow, etching speed of5.5m/min,developing speed of2.8m/min and exposure energy for60mJ. The reason of open andshort circuit is analyzed, put forward the solution to avoid failure.Parameters of CO2laser drilling machine was optimized and fitted to theinfluence of blind-hole morphology. When under the roundness index of orthogonalexperiment,the levels of related factors should be selected beam diameter of2.0; Laserpower:14.4mJ; Pulse number:1shot; Light pulse width:1, under the ratio of aperture,related best value factors level is laser beam diameter:2.2mm; Pulse width:2; Pulsenumber:3shot; Laser energy of14.2mj. The parameter fitting analysis showed the theinfluence of various parameters on the shape of vias. The process of drilling,d esmearand hole metallization was discussed to analysis the effects of interconnection holeaffects. In terms of substrate expansion, the same producers of flexible substrate andsubstrate rigidity are chose to manufacture processing, we find the the expansion scaleis under the theoretical value.A1：1drilling data can be used in the final through holedrilling process, so can acoid the deviation of layer to layer caused by thermalexpansion coefficient mismatch. Failure behavior caused by substrate expansion alsoare discussed in this paper.About the PCBA failure analysis,thermal shocking test is been used to discussthe reliability of BGA, the condition of thermal shocking be changed in this experiment.Metallographic microscopy observation introduced to analysis the company’s PCBAfailure cases.