Design of Advanced slit die structural for OLED-display module lamination

초록

Slit nozzle is applied like slot die in the lamination of optically clear resin (OCR) between display module and cover glass in mobile phone. In the slit lamination system, the internal structure of the slit nozzle is must be optimized to achieve the uniform thickness of coated resin with no air bubbles in it. It is formed by two chambers and a long slit channel. On the two chambers, reverse droplet-shaped and eye-shaped through-holes were perforated to keep the uniform velocity inside the die. In addition to this reference design, several combinations of number, interval, and height of the holes were tested and optimized through computational fluid dynamics (CFD) simulation package. OCR resin is modelled as a viscous Newtonian fluid and the internal fluid flow is assumed to be mostly laminar flow. In the optimized design, the variations of pressure and velocity of squeezed resin at the die exit were improved by around 6.0% better than already acceptable results of reference die design