Highly flexible cover window using ultra-thin glass for foldable displays

Ha, Myeong-Hun; Choi, Jong-Keun; Park, Byung Min; Han, Kwan-Young

doi:10.1007/s12206-021-0126-y

Cited by 43 publications

(28 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…They optimized the film stack through the bonding structure design of the OCA layer, where the viscoelastic properties were considered in the modeling process [15]. Ha et al used OCA as buffer layers to generate multiple neutral planes for stress control, where OCA was also simplified as a linear elastic material [16]. Yunsik et al conducted a finite element analysis and optimal design of a foldable display, during which only the hyperelastic properties were considered [17].…”

Section: Introductionmentioning

confidence: 99%

Mechanical Behavior and Constitutive Model Characterization of Optically Clear Adhesive in Flexible Devices

et al. 2022

View full text Add to dashboard Cite

Optically clear adhesive (OCA) has been widely used in flexible devices, where wavy stripes that cause troublesome long-term reliability problems often occur. The complex mechanical behavior of OCA should be studied, as it is related to the aforementioned problems. Therefore, it is necessary to establish reasonable mechanical constitutive models for deformation and stress control. In this work, hyperelastic and viscoelastic mechanical tests were carried out systematically and relative constitutive models of OCA material were established. We found that temperature has a great influence on OCA’s mechanical properties. The stress and modulus both decreased rapidly as the temperature increased. In the static viscoelasticity test, the initial stress at 85 °C was only 12.6 kPa, 57.4% lower than the initial stress at 30 °C. However, in the dynamic test, the storage modulus monotonically decreased from 1666.3 MPa to 0.6628 MPa as the temperature rose, and the decline rate reached the maximum near the glass transition temperature (Tg = 0 °C). The test data and constitutive models can be used as design references in the manufacturing process, as well as for product reliability evaluation.

show abstract

Section: Introductionmentioning

confidence: 99%

Mechanical Behavior and Constitutive Model Characterization of Optically Clear Adhesive in Flexible Devices

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Figure 1A shows a schematic illustration of the concept of completely foldable PTFTs. For a foldable device to be able to operate stably over its expected lifetime of 5 years, it must endure 200,000 folding cycles ( 30 ); this requirement necessitates a completely foldable transistor backplane. The photographic image in the bottom-left corner of Fig.…”

Section: Resultsmentioning

confidence: 99%

Completely foldable electronics based on homojunction polymer transistors and logics

et al. 2021

View full text Add to dashboard Cite

An increase in the demand for completely foldable electronics has motivated efforts for the development of conducting polymer electrodes having extraordinary mechanical stability. However, weak physical adhesion at intrinsic heterojunctions has been a challenge in foldable electronics. This paper reports the completely foldable polymer thin-film transistors (PTFTs) and logic gate arrays. Homojunction-based PTFTs were fabricated by selectively doping p-type diketopyrrolopyrrole-based semiconducting polymer films with FeCl3 to form source/drain electrodes. The doping process caused a gradual work function change with depth, which promoted charge injection to semiconducting regions and provided a low contact resistance. In addition, the interfacial adhesion in the PTFTs was improved by interfacial cross-linking between adjacent component layers. The electrical performance of the resulting PTFTs was maintained without noticeable degradation even after extreme folding, suggesting that the proposed fabrication strategy can further be applied to various semiconducting polymers for the realization of foldable electronics.

show abstract

“…For example, strengthened glass covers for handheld electronic devices have reached unprecedented levels of damage resistance and have even become foldable. [3] As another example, roll-to-roll processing of ultrathin and flexible glass substrates has been made possible; [4,5] advanced dicing and postprocessing techniques have led to defect-free and, thus, strong edges to withstand bending loads. [6,7] Thermal tempering has been enabled for thin-walled glass products, [8] usable in glass-glass solar modules, flexible mirror substrates, quadruple-glazing, and lightweight glass containers.…”

Section: Introductionmentioning

confidence: 99%

Advancing the Mechanical Performance of Glasses: Perspectives and Challenges

et al. 2022

View full text Add to dashboard Cite

in terms of deciphering structure-property relationships and the nonaffine nature of glass mechanical behavior, of computational and computer-assisted methods for accelerated materials discovery, and of physicochemical insight at glass formation and synthesis in unconventional types of materials. Despite this progress, significant questions remain as to the fundamental role of structural heterogeneity and its consequences for the predictability of mechanical properties underlying the many applications of glass. Today's challenge is to translate new understanding of the physics of disorder, glass chemistry, and surface mechanics into tools that enable future glass products with adapted elasticity, strength, and toughness. We will therefore consider fundamental advances in relation to emerging glass applications. While the aforementioned physical insights have mostly been obtained by computational simulation of model systems, and often through the examination of metallic glasses, we will here focus on glasses suitable for visible transparency, in particular silicate glasses, such as a representative of today's most prolific glass devices, ranging from ultrathin substrates to strong and visually transparent cover materials. We will further consider hybrid glasses and glass-like composite materials as emerging alternatives that may overcome the ubiquitous conflict between strength and toughness. [1] Glasses are materials that lack a crystalline microstructure and long-range atomic order. Instead, they feature heterogeneity and disorder on superstructural scales, which have profound consequences for their elastic response, material strength, fracture toughness, and the characteristics of dynamic fracture. These structure-property relations present a rich field of study in fundamental glass physics and are also becoming increasingly important in the design of modern materials with improved mechanical performance. A first step in this direction involves glass-like materials that retain optical transparency and the haptics of classical glass products, while overcoming the limitations of brittleness. Among these, novel types of oxide glasses, hybrid glasses, phase-separated glasses, and bioinspired glass-polymer composites hold significant promise. Such materials are designed from the bottom-up, building on structure-property relations, modeling of stresses and strains at relevant length scales, and machine learning predictions. Their fabrication requires a more scientifically driven approach to materials design and processing, building on the physics of structural disorder and its consequences for structural rearrangements, defect initiation, and dynamic fracture in response to mechanical load. In this article, a perspective is provided on this highly interdisciplinary field of research in terms of its most recent challenges and opportunities.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adma.202109029.

show abstract

Highly flexible cover window using ultra-thin glass for foldable displays

Cited by 43 publications

References 18 publications

Mechanical Behavior and Constitutive Model Characterization of Optically Clear Adhesive in Flexible Devices

Mechanical Behavior and Constitutive Model Characterization of Optically Clear Adhesive in Flexible Devices

Completely foldable electronics based on homojunction polymer transistors and logics

Advancing the Mechanical Performance of Glasses: Perspectives and Challenges

Contact Info

Product

Resources

About