Laser processing is widely used in the manufacture of surface patterns. However, it faces new challenges under some industrial demands. For example, the fine cladding circuit requires that the metal layer is precisely etched in depth for slight damage to the substrate and the formed conductive tracks have vertical sidewalls for higher precision. The former can be achieved by a reasonable control of the process parameters, but the latter is difficult to realize by conventional laser milling since the energy distribution of the spot is Gaussian. In this situation, a new laser processing method, pre-etching then sidewall trimming, is proposed to reduce the taper angle of the etched edge. It features an additional trimming process in which the laser process parameters are planned orderly for their relatively independent effect, and the multiaxis machining technology is introduced to realize the etching with oblique incidence. To control the etching depth in pre-etching, the ablation result of microgroove is predicted by building the laser ablation model at vertical incidence. Furthermore, the laser ablation model at oblique incidence is developed and the planning method of process parameters for the sidewall trimming is researched. The operation of the proposed processing method is completed through a five-axis laser processing machine tool. It is demonstrated that the prepared microgroove has the taper angle less than 3° (decrease degree > 90%). The research achievements improve the sloping sidewalls caused by the inherent characteristic of laser, which has practical application value for manufacturing the surface pattern with high-quality edge.

中文翻译：

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纳秒脉冲激光辐照金属，用于加工具有垂直侧壁的微槽

激光加工被广泛用于表面图案的制造中。然而，在某些工业需求下，它面临着新的挑战。例如，精细覆层电路要求深度精确地蚀刻金属层以对衬底造成轻微损坏，并且所形成的导电迹线具有垂直侧壁以实现更高的精度。前者可以通过合理地控制工艺参数来实现，但是后者很难通过常规的激光铣削来实现，因为光斑的能量分布是高斯分布。在这种情况下，提出了一种新的激光加工方法，先蚀刻后再修整侧壁，以减小蚀刻边缘的锥角。它具有附加的微调过程，其中有序地规划了激光工艺参数以实现相对独立的效果，引入了多轴加工技术，实现了斜入射刻蚀。为了控制预蚀刻中的蚀刻深度，通过建立垂直入射的激光烧蚀模型来预测微槽的烧蚀结果。此外，建立了斜入射激光烧蚀模型，并研究了用于侧壁修整的工艺参数的规划方法。所提出的加工方法的操作是通过五轴激光加工机床完成的。证明了所制备的微槽的锥角小于3°（降低度＞ 90％）。研究成果改善了激光固有特性引起的倾斜侧壁，对制造具有高质量边缘的表面图案具有实际应用价值。