| Microdroplet jetting forming technology is a feasible technical way to manufacture conformal bearing antennas,and conductive ink sintering is an important step in it.Near-infrared sintering is widely used due to its fast heating speed,high sintering efficiency and no damage to plastic substrates.The near-infrared sintering state is one of the key factors affecting the electrical properties of the nano-silver layer.In this thesis,the near-infrared sintering mechanism is not clear enough,the sintering controllability is poor,and it is difficult to ensure the electrical properties of the nano-silver layer.The near-infrared sintering mechanism was studied,and the controlled sintering of nano-metal ink was realized by the parameter feedback control method.Firstly,a near-infrared sintering model based on molecular dynamics was established at the microscopic scale,and the near-infrared sintering nano-silver ink was simulated by molecular dynamics method.The microscopic characteristic changes of the near-infrared sintered nano-silver ink were obtained by data analysis of different models,the micro-molecular level of sintering was defined,and the conductivity of the nano-silver layer was predicted by sintering neck calculation.Secondly,the sintering process was analyzed by the near-infrared sintering temperature field heat transfer model on the macro scale,the influence of different parameter changes on the sintering effect was studied,and the key parameters affecting the near-infrared sintering nano-silver ink were determined.The surface morphology changes and dense layer formation characteristics of nano-metal particles during sintering were analyzed at the mesoscopic scale,revealing the relationship between the morphology and electrical properties of the sintered films.On this basis,the near-infrared sintering temperature field heat transfer model,the surface morphology of the nano-silver layer and the molecular dynamics model were combined to systematically reveal the near-infrared sintering mechanism through a multi-scale method.Thirdly,through the multi-sensor detection system,the surface temperature distribution and morphology data of the nano-silver layer are fused to realize the evaluation of the surface flatness of the nano-silver layer and the analysis of the sintering degree.A near-infrared sintering parameter feedback control method is proposed,and the near-infrared sintering power,sintering time and other sintering parameters are adjusted according to the detection results of the multi-sensor topography detection system,so as to realize the near-infrared controllable sintering of nano-silver ink.Finally,the near-infrared printing and sintering integrated experimental platform was developed,and the integrated forming of the microstrip antenna was realized by the parameter feedback control method.The microstrip antenna with a center frequency of 10.02GHz was fabricated and its performance was tested.The conductivity is 2.73×10~7S/m.The return loss at the center frequency is-24.17d B,and the bandwidth is 939MHz.The measured results are close to the simulation results,which verifies the effectiveness of the near-infrared sintering parameter feedback control method. |
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