印制电路板超高转速钻削实验与仿真研究

发布时间：2018-09-08 20:12

【摘要】：为迎合现代社会对电子产品的集成化、便携化要求,PCB板正在向着高密度、多层化、轻薄化发展,PCB板上的微孔加工,是电子元器件实现电气互联的必要工序。本文一方面针对PCB板自身结构及其材料配比在超高转速的条件下对PCB板机械钻削性能的影响进行了一系列实验研究,将PCB板中各材料的质量比重定义为四个等级,并以5种典型PCB板中各材料的质量等级为参考,基于实验结果,采用对比分析的方法提出了分别以钻削温度、轴向力、微孔质量为指向的PCB优化方案。另一方面将PCB微孔钻削简化为对铜箔和多层玻璃纤维复合材料(GFRP)的钻削,在ABAQUS中成功建立了铜箔及多层GFRP有限元模型,并在超高转速条件下对两者进行了钻削模拟,且仿真有效。在实验研究方面,先后进行了钻削温度、轴向力以及孔质量的探究,以对比分析方法分析了PCB板材结构及各材料含量对钻削温度、钻削力、孔质量的影响,并归纳出以温度、钻削力、孔质量为指向的PCB结构及材料优化方案:以更优轴向力特性为目标的PCB钻孔,宜选用填料含量在16%-30%且树脂含量在31%-50%的双面PCB板;以取得更低钻削温度或更优孔质量为目标的PCB钻孔,应选用填料含量在31%-50%和树脂含量在16%-30%的多层PCB板,填料尺寸小且分布均匀时其效果更佳。在仿真研究方面,建立了基于Hasin损伤准则的多层GFRP有限元模型,和基于Johnson-cook剪切准则的铜箔有限元模型,并分别对两者进行钻削模拟。铜箔钻削仿真结果显示,在超高速钻削条件下,钻头两主切削刃温度分布明显不均,且主轴转速越高,这一现象越明显,温差随钻削深度加大而加剧。GFRP钻削仿真结果显示,钻削多层GFRP的应力可看作分别钻削单层复合材料的应力叠加,且叠加层数越多,层与层之间相互干涉程度越大;基体总是先于纤维破坏,且损伤程度高于纤维;纤维主要受到拉伸作用;多层GFRP孔较铜箔孔有明显的撕裂、起毛、分层现象,且随主轴转速降低而加剧。
[Abstract]:In order to meet the integration of electronic products in modern society, portable PCB board is developing towards high density, multilayer and thinning, which is the necessary procedure for electronic components to realize electrical interconnection. On the one hand, a series of experiments have been carried out to study the influence of the structure of PCB plate and its material ratio on the mechanical drilling performance of PCB plate under the condition of ultra-high speed. The weight specific gravity of each material in PCB plate is defined as four grades. Based on the experimental results, a PCB optimization scheme with drilling temperature, axial force and micropore mass as the direction is proposed based on the experimental results and the reference of each material quality grade in five typical PCB boards. On the other hand, PCB microhole drilling is simplified as drilling copper foil and multilayer glass fiber composite (GFRP). The finite element model of copper foil and multilayer GFRP is successfully established in ABAQUS. And the simulation is effective. In the aspect of experimental research, drilling temperature, axial force and hole quality have been studied successively. The effects of structure and material content of PCB sheet on drilling temperature, drilling force and hole quality have been analyzed by comparative analysis, and the temperature has been summarized. Drilling force and pore quality oriented PCB structure and material optimization scheme: for PCB drilling with better axial force characteristics, the double-sided PCB plate with packing content of 16-30% and resin content of 31- 50% should be selected. In order to obtain lower drilling temperature or better hole quality, multilayer PCB plates with packing content of 31% -50% and resin content of 16% -30% should be selected for PCB drilling. The effect is better when the packing size is small and the distribution is uniform. In the aspect of simulation, multi-layer GFRP finite element model based on Hasin damage criterion and copper foil finite element model based on Johnson-cook shearing criterion are established. The simulation results of copper foil drilling show that the temperature distribution of the two main cutting edges of the bit is obviously uneven under ultra-high speed drilling conditions, and the higher the spindle speed is, the more obvious this phenomenon is, and the temperature difference increases with the drilling depth. The simulation results show that the temperature difference increases with the drilling depth. The stress of multi-layer GFRP can be regarded as the superposition of the stress of single layer composites, and the more the number of stacked layers, the greater the degree of interference between layers, the matrix is always destroyed before fiber, and the degree of damage is higher than that of fiber. The fiber is mainly subjected to tensile action, and the multilayer GFRP pore has obvious tearing, piling and delamination phenomenon compared with the copper foil hole, and it is aggravated with the decrease of the spindle speed.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN41;TG52

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