Development And Application Of Film Preparation Instrument Based On Piezoelectric Spray Coating Technology

The advanced manufacturing industry,which is represented by microelectronics and optoelectronics,is becoming the core industry of the next generation of manufacturing industry.Thin film preparation technology is the technical foundation of microelectronics and optoelectronics industry.Producing the high-quality film efficiently is the core of today's film preparation.At present,we usually prepare the small-size devices with spin-coating method in the laboratory,and screen printing method is used to prepare the large-size devices,but these methods can not meet the requirements of large-scale,low cost and high efficiency in industrial production.Based on piezoelectric ultrasonic atomization technology and pressure atomization technology,this project has designed a swirl nozzle structure to achieve wide format preparation requirements and built the spray coating instrument.It has many advantages,such as high material utilization rate,preparation of large area devices,no-limitation in substrate materials and so on.Firstly,this paper analyzes the principle of ultrasonic atomization.Based on the principle of centrifugal pressure atomization and Abramovich's maximum flow principle,the size of the swirl nozzle can be calculated by empirical coefficient method and be checked to make sure it meets the requirements.Then,complete the design of the components of the nozzle.Finally,make the piezoelectric atomization nozzle be assembled.The experimental results show that the modified nozzle's spray angle is about 80°,and it proves that the optimized atomization nozzle can effectively improve the preparation efficiency of the film.Spray coating instrument mainly includes mechanical structure design and electrical control design.The mechanical structure section includes a thermally adjustable heating adsorption platform design and the total structure design of the instrument.The electrical control section includes the design of the 3D positioning platform and the touch screen operating platform with human-computer interaction function.The instrument can prepare the film on a variety of rigid or flexible substrates flexibly.In the experimental research,the film preparation process should be figured out based on piezoelectric film preparation instrument.Four main parameters have been identified as major influences on the spray coating processes.These are load pressure,nozzle to substrate distance,substrate temperature and solution feed rate.And the instrument can be adjusted to a good working condition according to the major influences.In the application research of spray coating instrument,it is applied to the preparation of flexible printed circuit(FPC),which can effectively solve the problem of low efficiency and high pollution in conventional FPC preparation.The specific means of implementation is:the nano-silver conductive ink is atomized by the ultrasonic nozzle and then sprayed on the Polyimide(PI)film which is covered with a metal mask.The ink is sintered to achieve the flexible circuit after patterning on PI film.The test results showed that the patterned circuit with a width of 500?m maintains good conductivity after several bending tests.With the increasing of the number of silver layers deposited,the surface sheet resistance of the inkjet-printed silver layer on PI film is steadily decreased.When the substrate gets eight sprays,the sheet resistance is 21 ± 2 m?/sq.In the SEM environment,the edge of the conductive line was observed to be smooth with the maximum error less than 50?m.The results show that the spray coating instrument has a great development and application prospect in the field of film preparation,and it is a feasible method to prepare the film efficiently.