Thermal vacuum drying device provided with pressure balancer and pressure balancer

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.