The Parallel Processing Method Of Femtosecond Laser And Its Application In FPC Micro-hole Machining

The femtosecond laser has an ultra-short pulse width,can act on the material in a very short time scale,and does not generate ablation.It belongs to “cold processing”,has a small heat-affected area,and has high precision.The single-pulse energy required for the femtosecond laser to make holes in metallic materials is often at the micro-focus level.The femtosecond laser output single pulse energy is much higher than the required energy.If the conventional single beam processing method is used,the output energy of the laser is high.Some are wasted and processing efficiency is low.Therefore,studying the femtosecond laser parallel processing has important research value and significance.In this paper,a spatial light modulator(SLM)is used in conjunction with the GSW algorithm to produce multiple beams to perform hole punching experiments on FPCs,which greatly improves the energy efficiency and processing efficiency of the laser.The main research contents of this paper are as follows:The second chapter of the thesis introduces the structural characteristics of FPC and the mechanism of the laser on the material,and the mechanism of the laser on the metal material.The two types of laser drilling methods,the impact drilling method and the contour detour method,are discussed at present,and the main influencing parameters affecting the laser pulse drilling are also introduced.In the third chapter of the thesis,the optical path is designed and a femtosecond laser single-beam punching experiment system is built.The pulse number and the influence of single pulse energy on the hole drilling are mainly analyzed to provide reference for the later multi-beam punching.In the fourth chapter of the dissertation,the femtosecond parallel processing system designed is introduced,including the optical path diagram designed,the phase modulation principle of the spatial light modulator and the 4F system are introduced in detail,and the principle and characteristics of the GSW algorithm are made.Detailed introduction.And the synchronous control system of multi-beam parallel processing was designed.This system was introduced in detail.In the fifth chapter of the thesis,the multi-beam holograms of the 10×10 array and the characters “H”,“B”,“U”,and “T” microhole clusters are calculated by using the GSW algorithm,and these holograms are loaded into the SLM using the CCD.The camera observes multiple beam effects and performs processing experiments on a flexible circuit board.The experimental results show that the method can produce up to 100 beams of multiple beams,the beam uniformity in character parallel processing exceeds 0.75,the aperture deviation in processing micro holes is 1.34 um,and the uniformity of multiple beams exceeds 0.87.Therefore,the micro-hole machining technology studied in this paper is an efficient parallel processing method.Finally,using the designed synchronous control system,the words "HBUT" and "LASER" were printed on the FPC.In the end,it is the summary and prospect of the paper,and provides some prospects and suggestions for the next research.