Henkel Corporation has introduced next generation Loctite® Liquid Optically Clear Adhesives (LOCA) that increase display durability, improve contrast ratio, reduce power consumption and enable thinner device designs. New adhesives for direct bonding and cover lens bonding simplify display assembly, while advanced cleaners reduce the overall manufacturing cost with more effective manual and automated rework cleaning processes.
The rapid adoption of new display touch technologies such as in-cell, on-cell, one glass solution and GFF are rapidly eliminating touch panels from display designs and making direct bonding critically important. Loctite® ultra-soft LOCAs for direct bonding reduce the potential for MURA, while filling gaps from 200 to 300 microns. Loctite® 3191™, 3198™ and 3199™ are low durometer, low modulus and low shrinkage materials that also deliver high tensile and adhesion strength on polarizer films, PMMA, glass and ITO-coated glass to prevent delamination during RA testing.
For glass-to-glass or plastic-to-glass cover lens bonding applications, Loctite® 3193HS™ and 3194™, withstand stresses created by the substrates’ differing coefficients of thermal expansion. These fast-flowing, low viscosity materials cure with light in seconds when filling gaps from 100 to 200 microns and achieve up to 7 MPA cross tensile strength. Ideal for use on glass, PMMA, ITO-coated glass and ITO-coated PET films, these adhesives have a lower cycle time in the manufacturing process and are more resistant to delamination than previous generation products.
Two new Loctite® cleaners easily remove residues of uncured and cured adhesives from display surfaces. For use in manual assembly processes, the Loctite® SF 7190™ hand wipe cleaner features a fast evaporating solvent that is designed to wipe easily onto surfaces and eliminate dust, finger prints, and residues or small cured particles of adhesive. For automated assembly processes, Loctite® SF 7191™ is a slow evaporating, high flash point solvent that removes LOCAs that have fully cured after approximately 0.5 to 2 hours of exposure to the cleaner.