Key Technologies Research On Laser Sintering Of Spray Forming System

One of the key steps in the manufacture of microstrip patch antennas,circuit boards,frequency selective radome,and other electronic equipment using spray forming technology is to sinter the sprayed material,to make the sprayed pattern has conductive characteristics.The laser has the characteristics of guiding property,energy concentration,and small temperature field.It can sinter and cure the spray pattern.In this thesis,a particle-free silver-based metal organic decomposition(MOD)ink is used as a spray material,and the laser sintering process of the ink is analyzed and studied.First,this thesis analyzes the properties about the optical and thermal effect of laser acts on the ink,and the the decomposition process of ink is studied.The wavelength of the laser used in this thesis is determined by studying the absorption of different wavelengths of light by ink and the depth of penetration of different wavelength lasers in the ink.The decomposition process of ink is studied by differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA).the temperature range of high and low boiling point solvent volatilization and chelate decomposition of ink is obtained.Secondly,the numerical simulation of laser sintered MOD ink is carried out by using finite element analysis software COMSOL Multiphysics.The thermal conductivity of ink is obtained by experiments,and other heat material parameters is modified by experiments to establish the simulation model.The influence of different laser sintering process parameters(output power,scanning speed,scanning interval)on the sintering temperature field is simulated.The variation law of temperature field under different process parameters is obtained.Thirdly,the laser sintering curing system is developed according to the control requirement of laser sintering process.The three axis motion platform is used to realize the spatial motion of the spot,the servo control hardware is selected,the control software is developed and the sintering path is planned.Finally,the sintering experiment is carried out and the sintering process is optimized by using the sintered curing equipment.According to the line width test,conductivity test, silver film thickness test,electron scanning microscope test,energy spectrum measurement of the sintered conductive pattern at different output power,scanning speed and scanning interval,The cause of the difference in sintering quality is studied,the parameters of laser sintering are optimized,and the microstrip patch antenna is fabricated by this process.The testing performance meets the requirements.In this thesis,the study laser sintering process of MOD ink,is helpful to determine the research direction of the laser sintering technology in the spray forming,which lays a foundation for the study of heterogeneous heterogeneous spray forming of electronic equipment.