Research On The Influencing Factors Of Precision In Preparation Of Flexible Polymer Film By Spin Coating

In recent years,the development of flexible electronics industry has put fo rward higher requirements for the uniformity,flatness and production cost of flexible films.In the field of some functional components such as integrated circuits,the film in order to protect the microstructures on the upper surface of the substrate is required to have a high degree of flatness.In order to effectively improve the performance of these functional devices,the films of uniform and controllable thickness on planar and curved surfaces are facing great challenges.Spin coating as an efficient,simple,low-cost and pollution-free thin film preparation method is attracting more and more attention.In spin coating process,spin coating parameters have an important effect on the accuracy of film.The common parameters affecting the film thickness include spin coating speed,spin coating time,solution viscosity and solvent evaporation rate.The fluid flow in spin coating to makes the uniformity of the film is very complex.There are few reports on the relationship between the shape of the substrate and the thickness of the film and the influence of the surface shape on the edge effect.Therefore,it is very important to study the influence of the surface shape on the spin coating process.In this paper,the uniformity of the film thickness on the substrate surface during the process of spin coating is studied.At the same time,the parameter of the edge effect is put forward,and the process of the polymer film spin coating on the surface of the microstructure is studied.the preparation method of the upper surface can be obtained.The research content of this article is as follows.(1)The influence of solvent volatilization,drop point eccentricity,base surface shape and spin coating velocity on film thickness was studied by experimental method.The effect of solvent volatilization on the thickness of the whole film was found to be 1.5%.At low velocity(Lower than 3000 rpm),the surface shape has a great influence on the thickness distribution of the film.At high speed(Higher than 3000 rpm),the speed is the main factor affecting the thickness of the film.(2)Based on the experimental and simulated results of the film edge effect on the plane,concave and convex substrate,it is concluded that the influence of the thickness of the film on the edge effect is like parabolic curve instead of linear dependence.The edge effect is minimum when the film thickness is about 20 ?m,and it is found that the edge effect on the concave face can be effectively suppressed.The inhibition effect can reach 10%,a nd the concave side effect is more effective than the convex face.(3)The experimental study o f the substrate with microstructures is carried out.Through the comparison of five kinds of thin film flat technology,it is proposed that the clearance spin coating process can effectively achieve the smoothness of the film on the surface of the micro structure,and the height difference can be decreased to 20% of the original height.At the same time,the speed and pressure of the spin coating on the spreading speed of the liquid film in the gap are also studied.In the initial stage of spin coating,it is found that the pressure has a decisive effect on the spreading speed of the liquid film.With the radial spread of the liquid film,the influence of the spin coating speed on the spreading speed of the liquid film gradually becomes larger.