Research On Multifocal Picosecond Laser Stealth Dicing Brittle Materials

With the rapid development of optoelectronic industry and optical communication industry,brittle materials are widely used in LED chips and fiber optic PLC plane waveguide optical splitter and other chips because of their good comprehensive performance.The improvement of technology and the needs of the market promote these chips to the miniaturization,high density,high-speed direction.Wafer can get high performance,high yield,high stability of the chip by the sticky film,cutting,grinding and polishing process.Effectively improving the number of products within a single wafer,narrow tape structure has been a lot of attention.While reducing production costs,increasing productivity and product quality is the focus of current focus.Therefore,,dicing technology and methods on sapphire,quartz brittle materials in the practical production applications have a pivotal role.This paper has developed a laser multifocal stealth machining optical system designed to realize the high quality and high efficiency processing of brittle and transparent materials such as quartz and sapphire,and provide a new idea and technology method for the production of wafer such as sapphire filament and PLC chip.Firstly,the transmission characteristics of the brittle materials were analyzed.Based on the theory of transient heat conduction,the theory of thermoelasticity and the theory of fracture mechanics,the fracture mechanism of laser and brittle materials is analyzed.Finally,the relationship between laser and brittle materials is analyzed.Focusing on stealth cutting mechanism is for the subsequent laser multifocal stealth cutting separation of brittle materials to lay the theoretical basis.Secondly,the laser stealth processing system is discussed in detail.The principle of the optical path system,the motion system and the cooling system is analyzed,and the processing process of the laser stealth cutting is described.Then the optical principle of the laser multifocal processing system is explained in detail.At the same time,the quantitative design process of multifocal system in ZEMAX is briefly discussed.Finally,the experimental study of picosecond multifocal stealth cutting brittle materials was carried out.The results show that the effects of laser parameters on the quality of cutting are analyzed by the control variable method,and the effects of laser parameters on the cutting quality are analyzed by the control variable method.The effects of laser parameters on the cutting quality are analyzed.The experimental results show that some experimental phenomena are explained.The laser multifocal stealth is used to cut the PLC chip,and the experimental results are studied.The effect of multifocal stealth cutting is analyzed.