A thermal vacuum drying device and a pressure balancer provided with a pressure balancer

Abstract

The invention discloses a thermal vacuum drying device. The thermal vacuum drying device comprises a cavity. Vacuum adsorption ports are formed in the two side faces of the cavity. One end of a vacuumizing branch pipe is connected with the vacuum adsorption ports, and the other end of the vacuumizing branch pipe is converged to one end of a vacuumizing main pipe. The other end of the vacuumizing main pipe is connected with a vacuum pump unit. A pressure balancer is arranged in the convergence of the vacuumizing branch pipe and the vacuumizing main pipe. The pressure balancer comprises a U-shaped pipe and a vacuumizing main pipe funnel-shaped part. The vacuumizing branch pipe extends to the bottom of the U-shaped pipe. The top of the U-shaped pipe is sealed. Air holes are formed in the two sides of the U-shaped pipe. The U-shaped pipe is communicated with the transversely arranged vacuumizing main pipe funnel-shaped part through the air holes. By means of the buffer effect of the U-shaped pipe of the pressure balancer, the pressures of all branch pipes are adjusted to be consistent, and thus the pressure of the whole hot dry vacuum (HVCD) cavity and the pressure of part of the HVCD cavity are held to be stable; polyimide solution airflow is constant; the MURA defects are reduced; the film texture of flexible substrates is improved; the processing yield is increased.

Description

technical field [0001] The invention relates to the technical field of flexible display product manufacturing, in particular to a thermal vacuum drying device and a pressure balancer provided with a pressure balancer. Background technique [0002] Making flexible substrates from flexible polyimide (Flexible Polyimide, referred to as: flexible PI) and applying them to the production of flexible display products is one of the current hot topics in the manufacture of flexible display products. Because the flexible polyimide has the characteristics of high viscosity and hydrophobicity, its precursor polyimide solution (polyimide solution) contains a relatively large amount of solvent NMP (the weight percentage of the solvent NMP amount is ≥ 70%). After the polyimide solution is coated, it generally needs to go through a hot vacuum drying (Hot Dry Vacuum, HVCD) process, and then put it in an oven for curing process. Due to the high solvent content of polyimide solution (PI Solve...

AI Technical Summary

Problems solved by technology

This setting method is likely to cause uneven pressure in each vacuum branch pipe, resulting in local pressure unevenness in the chamber of the hot vacuum drying HVCD device. When the polyimide solvent is extracted, the air flow is disordered, so that the (PI Film) Irregular shape MURA produced on the surface

Images