Research On FPC CCL Etching And Fine Line Forming Technology Based On Femtosecond Laser

Due to its short pulse width and high peak power,femtosecond lasers have minimal thermal impact during processing and are therefore widely used in micro-nano processing.As electronic products move toward miniaturization and light weight,the market's requirements for FPC integration are further enhanced.The traditional processing method cannot meet this integration requirement due to the limitations of its own technology.In view of the above problems,this paper proposes a FPC copper clad micro-wire forming technology based on multi-wavelength femtosecond laser.Specific research work:(1)The interaction mechanism between femtosecond laser and metal and polymer materials is expounded from the perspectives of laser energy absorption and material migration.Meanwhile,the ablative analytical formula of femtosecond laser monopulse is obtained by simplifying the two-photon absorption model and two-temperature model.(2)Based on the double temperature equation,the MATLAB software was used to simulate the change of electron and lattice temperature during the etching of FPC copper layer.From the perspective of temperature change,the pulse interval time and pulse width were analyzed.Three factors,such as laser energy density,affect the changes in electron and lattice temperature,and explore the causes of the changes.(3)Using the femtosecond laser in the ultraviolet and infrared bands to perform single?factor window etching on the FPC copper clad copper layer and the substrate layer respectively,the laser power,scanning speed,scanning times,defocusing amount,laser frequency and scanning were obtained.The influence of parameters such as line spacing on the etching effect,and orthogonal test on the basis of this,the influence weight of each process parameter on the engraving quality is obtained.The analysis results show that the influence of the number of scans on the etching quality of the copper layer is weighted.The maximum;and the laser power has the greatest influence on the etching quality of the substrate layer.In addition,the optimal balance method is used to balance the optimal scheme under each index,and the optimal etching process parameters of the copper layer and the substrate layer are obtained respectively.(4)The comparative etching test of single and side-by-side wire was carried out with the optimal process parameters,according to the measurement results,the forming rules and optimal forming conditions of single wire and side-by-side wire are discussed.On the basis of etching of conductor,complete fine line processing was carried out on FPC copper clad plate,and a conductive line with a width of 29.33mm was produced.The research results show that high-quality fine line forming can be achieved by etching the FPC copper clad laminate under optimized femtosecond laser conditions using optimized process parameters and scanning patterns.Compared with the traditional line processing method,the precision of the line forming and the forming efficiency are improved,and the line integration degree of the FPC is also improved,which proves that the processing method has certain feasibility in actual production.