Novel versatile pressure-sensitive adhesives for polarizing film of TFT-LCDs: Viscoelastic characteristics and light leakage performance

Solvent-Free Deposition of Ultrathin Copolymer Films with Tunable Viscoelasticity for Application to Pressure-Sensitive Adhesives

“…Pressure-sensitive adhesive (PSA) is a viscoelastic material that is sticky at room temperature and readily adherent to various heterogeneous substrate materials simply by applying a light pressure. , PSA is used widely in our daily life as well as in various industrial fields including electronics, , displays, − encapsulation, − and biomedical devices because the adhesive layer provides an extremely simple means to bond two different substrates without damaging them, and can also be removed easily, if necessary. In particular, PSA is critically important in many aspects for the fabrication of electronic devices.…”

“…In particular, PSA is critically important in many aspects for the fabrication of electronic devices. For example, it can be applied to laminate polarizers, antireflective films, and touch panels and to stack components within electronic equipment. − Recently, many research groups have attempted to render electronic devices mechanically flexible or stretchable. − Previous reports , indicated that the flexibility is directly associated with the thickness of the substrate, and a great deal of research has been devoted to reducing the total device thickness to as low as 20 μm without mechanical failure in the functional component layers to secure flexibility of the electronic devices. , Accordingly, the thickness of the PSA must also be scaled down substantially. In addition, the viscoelastic characteristics of the PSA can allow it to serve as a soft layer to release the potential interfacial stress caused by bending the laminated substrates .…”

Influence of Selected Crosslinking Agents and Selected Unsaturated Copolymerizable Photoinitiators Referring to the Shrinkage Resistance of Solvent-Based Acrylic Pressure-Sensitive Adhesives

“…The problem of shrinkage does not only affect PSAs on PVC protective films. The widespread use of PSA in TFT-LCDs or modern OLEDs, including the latest flexible displays, makes it necessary to take this PSA property into account when developing new adhesives [ 19 , 20 ]. Despite the significant advances in display technology, the dimensional stability of the adhesive layers connecting the subsequent parts of the displays is important for their durability.…”

Stress and stress relaxation behaviors of multi-layered polarizer structures under a reliability test condition characterized by use of a bending beam technique

“…[8][9][10] An inherent problem of lamination-based structures such as an LCD polarizer is dimensional instability, which causes distortion of polarizer films upon the completion of fabrication processes or after thermal and=or humidity cycling testing, resulting in light-leakage phenomena. 7,[10][11][12][13][14][15][16][17][18] Such thermally induced distortion is mainly driven by mismatches in the coefficients of thermal expansion (CTE) and modulus (E) between different functional films, and between these films and the substrate. This stress may impose serious reliability issues and cause mechanical failure of films, such as warpage, 7) contact peel-off 13,16) and phase retardation or light-leakage phenomena.…”

“…7,[10][11][12][13][14][15][16][17][18] Such thermally induced distortion is mainly driven by mismatches in the coefficients of thermal expansion (CTE) and modulus (E) between different functional films, and between these films and the substrate. This stress may impose serious reliability issues and cause mechanical failure of films, such as warpage, 7) contact peel-off 13,16) and phase retardation or light-leakage phenomena. 18) To date, a vast amount of studies [13][14][15][16][17][19][20][21] have focused on the relationship between modified materials such as adhesive layers, and their optical characteristics, with the aim of reducing light-leakage.…”