The flexible printed circuit (FPC) board with the characteristic of light and thin strengthened confronted the growing miniaturization requirements of the electronic product and the popularity of wearable devices. The reliability of circuit could be influenced by the hole quality of FPC, such as burrs, which is one of the major problem in FPC.,In this paper, micro-drill with a diameter of 0.1 mm was used to drill the double-sided flexible copper clad laminate. The thrust force, the burr and tool wear were investigated. The influencing factors of the height of the burrs were studied. The relationship between the thrust force and the height of the burrs was also explored. Finally, the formation mechanism of burrs was analyzed.,The entrance burrs were usually less than the exit burrs. The burr height increased with the feed per rotation. The height of the burr increased with the increase of the thrust force for the plastic deformation of the copper foil was dominant. The abrasion of the drill gave rise to increase the height of burr. In micro-hole drilling, the growth of burrs can be suppressed effectively by reducing the clearance between the FPC and the backup plate. The thrust force would be controlled in a certain range to reduce the burr with specific drilling parameters. There existed a certain relationship of Gaussian distribution between the height of the burrs and the thrust force of FPC.,The reliability of the integrated circuit was directly affected by the burrs of the FPC. This research on the formation mechanism of FPC burrs and forecast of burr height provided a firm foundation for further work in the area of improvement of the micro-hole quality.

中文翻译：

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柔性印刷电路板微孔毛刺形成及其影响研究

柔性印刷电路板（FPC）具有轻薄强化的特点，面对电子产品日益增长的小型化要求和可穿戴设备的普及。FPC 的孔质量会影响电路的可靠性，例如毛刺，这是 FPC 的主要问题之一。本文使用直径为 0.1 mm 的微型钻在双面钻孔。柔性覆铜板。研究了推力、毛刺和工具磨损。研究了毛刺高度的影响因素。还探讨了推力与毛刺高度之间的关系。最后分析了毛刺的形成机理，入口毛刺通常小于出口毛刺。毛刺高度随着每转的进给而增加。毛刺高度随着推力的增加而增加，铜箔塑性变形占主导地位。钻头的磨损导致毛刺高度增加。在微孔加工中，通过减小 FPC 和支撑板之间的间隙可以有效抑制毛刺的生长。将推力控制在一定范围内，以减少特定钻孔参数的毛刺。毛刺高度与FPC推力之间存在一定的高斯分布关系。FPC的毛刺直接影响集成电路的可靠性。本次对FPC毛刺形成机理及毛刺高度预测的研究为进一步提高微孔质量提供了坚实的基础。