With the development of the Internet of Things, the use of flexible displays has become widespread. In particular, the use of curved, bendable, and rollable displays is increasing. Flexible display production processes include various important components such as lamination material, flexible substrates, and adhesives. Among them, improvement of the lamination process comprises a large proportion of efforts for further development. In this paper, we attempt to improve the transmittance of the display substrate by performing a bubble removal process after adhesion. The transmittance of the glass substrate with the bubble removal process was 5~12% higher than that of the substrate without the bubble removal process. The fill-strength after the bubble removal process was improved by 21.4%, and the shear-strength was improved by 43.9%.