Method for removing bubbles in polyimide solution

Abstract

The invention provides a method for removing bubbles in a polyimide solution. The method comprises steps as follows: the polyimide solution is contained in an open container; a microwave generator is used for emitting microwaves to the polyimide solution for microwave treatment for a certain period to remove the bubbles in the polyimide solution. The polyimide solution is treated with the method, so that the bubbles in the polyimide solution can be removed conveniently and rapidly, the time for the process is greatly shortened, the industrialization requirement is met, meanwhile, the volatilization of a low-melting-point organic solvent in the polyimide solution is effectively reduced, the stability of the proportion of the polyimide solution is maintained, and defects during follow-up coating are avoided.

Description

technical field [0001] The invention relates to a treatment method for polyimide, in particular to a method for removing air bubbles in a polyimide solution. Background technique [0002] Polyimide refers to a class of polymers containing imide rings (-CO-NH-CO-) on the main chain, among which polymers containing phthalimide structures are the most important. As a special engineering material, polyimide has been widely used in aviation, aerospace, microelectronics, nanometer, liquid crystal, separation membrane, laser and other fields. In the 1960s, all countries listed the research, development and utilization of polyimide as one of the most promising engineering plastics in the 21st century. Because of its outstanding characteristics in performance and synthesis, polyimide, whether as a structural material or as a functional material, has been fully recognized for its huge application prospects, and is known as a "problem-solving expert" (protion solver), and believes th...

AI Technical Summary

Problems solved by technology

[0004] Existing polyimide solutions often contain a large number of micron-sized bubbles, and the bubbles cannot be effectively squeezed out during and after coating. In the subsequent drying and baking stages, these bubbles will The imide surface diffuses to form pores of a certain size (1-4μm), such as figure 2 As shown, these pores will fall off in the subsequent process, such as image 3 As shown, thus seriously affecting the stability of subsequent processes

[0005] The method commonly used at present to remove bubbles in the polyimide solution is to place the polyimide solution in a vacuum environment for a long time (36 to 72 hours) and vacuumize it all the time, but there are many deficiencies in such a method. On the one hand It takes a long time and cannot adapt to the needs of industrialized mass production. On the other hand, vacuuming always easily causes the low melting point organic solvent (such as N-methylpyrrolidone, etc.) in the polyimide solution to volatilize and cause polyimide The ratio of the solution deviates from the original composition, which will cause defects in the subsequent coating process

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