Pressure-Sensitive Adhesives for Flexible Display Applications

Abstract

Pressure-sensitive adhesives (PSA) have been used in electronics for not only attachment of two materials but also shock absorption, thermal and electrical conductivity, electromagnetic shielding, and optical property. Optically clear adhesives (OCA) have been used as a core material for optical performance of display. In addition to basic properties of OCA such as adhesion strength, transmittance, haze, and reliability, it has required dielectric constant, gap filling, and anticorrosion according to a substrate. However, the structural and functional changes of flexible display bring challenges to OCA that protects vulnerable components such as thin-film transistor, OLED, and thin-film encapsulation by stress dispersion and adjustment of a neutral plane. At the same time, flexibility and existing properties are essential. In this chapter, the development of components and performance of OCA, and evaluation methods will be discussed.

Impact energy absorption of block copolymer/tackifier blends: Effect of compatibility, viscoelasticity, and laminate structures

“…where ΔE V is the cohesion energy [J/mol] and V M is the molar volume [cm 3 /mol]. 40 Hansen divided both ΔE V and δt into three components based on dispersion interactions (ΔE V d and δd), dipole interactions (ΔE V p and δp) and hydrogen-bonding interactions (ΔE V h and δh).…”

“…Consequently, these materials are widely used in packaging, medical, automotive, and electronics applications. [1][2][3][4] As an example, many components found in mobile phones are held in place using PSA tape. In addition to high adhesive strength, PSA tapes are able to absorb impact energy, which can reduce damage in the case that a device is subjected to shock, such as when dropped.…”

“…Pressure sensitive adhesives (PSAs) are functional polymers capable of rapidly adhering to many substrates in response to the application of minimal pressure. Consequently, these materials are widely used in packaging, medical, automotive, and electronics applications 1–4 . As an example, many components found in mobile phones are held in place using PSA tape.…”

Highly Stretchable, Soft, and Clear Viscoelastic Film with Good Recoverability for Flexible Display

“…Ideally, the light emitting layer is the so-called neutral plane (i.e., no stress) layer. Since most display layers are rigid and CVF is inherently soft and elastic, CVF plays a critical role in minimizing the stress and optimizing the folding mechanics of the display panel. , …”

“…One of the reasons lies in the fact that many performance requirements are contradictory. , Typically, the CVF can be in the form of a PSA film or liquid adhesive. PSA film is the leading commercialization choice as the bonding of different functional layers in the display module through lamination is straightforward with high production yield . PSA is a viscoelastic material with the viscous component contributing to surface wetting when the PSA is brought in contact with the adherent and the elastic component mainly contributing to the cohesion.…”