基于断裂机理的板级电路光纤埋入结构设计

板级光电互联中,光纤埋入结构的设计既要保证光路地对准,又要保证光纤在层压工艺过程中不被破坏,这大大增加了PCB制造的难度。针对光纤埋入工艺过程中可能出现的问题进行分析研究,设计一种新的光纤埋入结构。对光纤埋入工艺与光纤断裂机理进行理论分析;基于有限元理论建立光纤埋入结构的仿真模型,对光纤埋入工艺进行数值模拟分析。结果表明,填充环氧树脂胶可降低层压过程中光纤所受最大应力,并且刻槽形状对光纤所受最大应力也有影响。设计一种新的槽型结构并对它进行了光纤埋入过程中的应力分析,研究光纤所受最大应力与槽底角度和侧壁间距的关系,并结合工程实际,分析了光纤尺寸公差和划片机加工精度对其应力的影响。研究表明,该板级电路光纤埋入结构设计在保证光路对准的基础上,制造过程中光纤所受的最大应力明显降低,具有较好的可加工性。

Design of the Optical Fiber Embedded Structure in PCB-Level Circuit Based on the Fracture Mechanism

The designs of the optical fiber embedded structure in PCB-level circuit not only needs optical link alignment, but also ensure that fiber is not damaged in the process of laminating process. It increases the difficulty to PCB manufacturing. So the problems which may take place during the manufacturing process and design a new kind of optical fiber embedded structure is studied. Optical fiber embedded process is introduced and optical fiber fracture mechanism is analyzed in theory. The simulation model of the optical fiber embedded structure based on the finite element theory is established and the optical fiber embedded process was analyzed by numerical simulation. The results indicate that the maximum stress in the lamination process can be reduced by filling with epoxy glue and the groove shapes also have influence on the maximum stress. An original groove type topology structure is designed. The stress condition is analyzed when optical fiber embedding the groove structure and discussed the relationship between the maximum stress on optical fiber and the angle in the bottom of the groove, also the distance optical fiber to the groove wall. Combined with practical engineering, the influence is researched which to the stress caused by fiber size tolerance and scribing machining precision. It shows that the design of the optical fiber embedded structure not only effectively reduces the maximum stress which the fiber enduring in the manufacturing process, but also has good workability on the premise of guaranteeing optical link alignment.