Polyimide film with high dimensional stability and preparation method of polyimide film

Abstract

The invention discloses a polyimide film with high dimensional stability and a preparation method of the polyimide film. The polyimide film is prepared from at least one aromatic dianhydride containing a rigid structure and at least one aromatic diamine containing a rigid structure through a solution polycondensation reaction and an imidization reaction, wherein the sum of mole numbers of the aromatic dianhydride containing the rigid structure and the aromatic diamine containing the rigid structure accounts for 70-85% of the sum of mole numbers of totally reacted dianhydrides and diamines; the film thickness is 5-75 microns; the thermal shrinkage ratios of the film in the longitudinal direction and the transverse direction are respectively less than or equal to 0.1%; the coefficient of linear thermal expansion is less than or equal to 16ppm; and the operating requirements of a polyimide film base material of a flexible copper clad laminate are met. According to the preparation process of the film, a roll-to-roll production manner of performing continuous longitudinal stretching technology according to a constant speed ratio and transverse high-temperature stretching and online thermosetting treatment is adopted, the prepared polyimide film has excellent dimensional stability performance, and the production manner adopted by the film is simple, convenient, high-efficiency and reliable.

Description

technical field [0001] The invention relates to the field of high molecular polymer materials, and more specifically relates to a highly dimensionally stable polyimide film material. Background technique [0002] With the development of miniaturization and thinning of electronic equipment, the rapid development of high-density internal flexible circuit board (FPC) wiring patterns and high-density assembly of electronic devices on circuit boards, polyimide films as flexible circuit substrates Higher requirements are put forward in terms of dimensional stability, and the thermal shrinkage rate of the film is required to be ≤0.1%, and the linear thermal expansion coefficient is ≤16ppm. However, in terms of dimensional stability, such as thermal shrinkage rate and linear thermal expansion It is difficult to meet the requirements of flexible circuit substrates at the same time. [0003] In the field of flexible circuit boards, the heat shrinkage test of polyimide substrate is a ...

AI Technical Summary

Problems solved by technology

This patent improves the performance of the film by adding a new physical mechanism, making full use of the existing production line equipment, but the method still makes the production process complicated, and the new equipment puts forward requirements for the space of the production line, and the final product is in the production line. Although the thermal shrinkage rate is controlled within 0.10%, the isotropic linear thermal expansion coefficient is still at the level of 32ppm, which is obviously insufficient for downstream use

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