异质多元多层印制电路板精密孔机械加工

孔是实现印制电路板层间互联及电子元器件装配的核心组成单元，机械钻孔是印制电路板制孔的主要方法。要在印制电路板上进行高密集度孔群的连续可靠、高质量、高一致性和高稳定性加工非常困难，涉及的异质多元多层复合材料机械加工理论复杂，也对加工刀具、加工技术提出了严峻挑战。从机械加工的角度归纳了典型印制电路板分类、组成结构与热力学特性，并提出其机械钻孔加工面临的难点；从材料变形与断裂、钻削热、钻削力与扭矩、孔创成机理、刀具失效机制五个方面，总结了典型印制电路板钻削理论的最新进展，综述了印制电路板用钻头设计、钻孔加工工艺和钻削过程检测技术的研究现状，从印制电路板微孔钻削加工理论、微细刀具优化设计、低温介质辅助钻削加工与孔质量无损检测方面指出了现有研究存在的问题，并结合新一代高端印制电路板发展趋势与孔制造需求，提出了未来印制电路板孔加工研究应重点关注的方向。

Drilling of Heterogeneous Multi-layer Printed Circuit Boards: A review

The hole in the printed circuit board (PCB) is the core unit that realizes the interconnection between the layers and the assembly of electronic components, and mechanical drilling is the main method of making holes in PCBs. Continuous reliable, consistent, and stable machining of high-density and high-quality holes in PCBs is very difficult. The processing theory of heterogeneous multi-layer composite materials involved is complex, and it also poses severe challenges to drilling tools and processing technology. The classification, composition and thermodynamic properties of typical PCB substrates are summarized, and the difficulties faced by the mechanical drilling processing are proposed. The latest research progress of typical PCB hole machining theory is summarized from five aspects: material deformation and fracture, drilling heat, drilling force and torque, hole creation mechanism, and tool failure mechanism. The research status of drill design, drilling processing technology and detection technology are also reviewed. Some existing problems of micro-hole drilling mechanism, optimal design of micro-tools, cryogenic assisted drilling processing and non-destructive detection of hole quality are also described. Combined with the development trend of the new generation of high-end PCB and the requirements of hole fabrication, the research directions that should be focused on in the future of PCB drilling are prospected.