scholarly journals Investigation of the Chemical Structure of Ultra-Thin Polyimide Substrate for the Xenon Flash Lamp Lift-off Technology

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 546
Author(s):  
Seong Hyun Jang ◽  
Young Joon Han ◽  
Sang Yoon Lee ◽  
Geonho Lee ◽  
Jae Woong Jung ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Chemical Structure ◽  
Surface Characteristics ◽  
Dielectric Constants ◽  
Flash Lamp ◽  
Next Generation ◽  
Polyimide Films ◽  
Chemical Structures ◽  
Polyimide Substrate ◽  
Lift Off

Lift-off is one of the last steps in the production of next-generation flexible electronics. It is important that this step is completed quickly to prevent damage to ultrathin manufactured electronics. This study investigated the chemical structure of polyimide most suitable for the Xe Flash lamp–Lift-Off process, a next-generation lift-off technology that will replace the current dominant laser lift-off process. Based on the characteristics of the peeled-off polyimide films, the Xe Flash lamp based lift-off mechanism was identified as photothermal decomposition. This occurs by thermal conduction via light-to-heat conversion. The synthesized polyimide films treated with the Xe Flash lamp–Lift-Off process exhibited various thermal, optical, dielectric, and surface characteristics depending on their chemical structures. The polyimide molecules with high concentrations of –CF3 functional groups and kinked chemical structures demonstrated the most promising peeling properties, optical transparencies, and dielectric constants. In particular, an ultra-thin polyimide substrate (6 μm) was successfully fabricated and showed potential for use in next-generation flexible electronics.

Morphology and Dielectric Property of Cellular Polyimide Films Prepared by Phase Inversion

2012 ◽  
Vol 557-559 ◽  
pp. 704-707
Author(s):  
Hui Juan Chu ◽  
Hong Liang Wei ◽  
Jing Zhu ◽  
Bao Ku Zhu ◽  
You Yi Xu
Keyword(s):  
Dielectric Properties ◽  
Dielectric Property ◽  
Phase Inversion ◽  
Polymeric Materials ◽  
Dielectric Constants ◽  
Cellular Structures ◽  
Coagulation Bath ◽  
Inversion Method ◽  
Polyimide Films ◽  
Chemical Structures

In order to explore low dielectric polymeric materials, two types of cellular polyimide films with different dianhydride units were prepared by phase inversion method, and their dielectric properties were investigated. Polyimide films with various cellular structures were obtained by controlling coagulation bath compositions and temperatures. The effects of chemical structures, cellular structures on dielectric property of cellular polyimide films were studied. The results showed that all of the cellular polyimide films had lower dielectric constants than the polymer matrix. The dielectric properties were influenced dominantly by the morphologies of the films. Cellular Polyimide films filled with uniform small cellular structures behaved excellent dielectric property compared with those large-pore cellular films. These findings would provide potential application for cellular polyimide films in microelectronic devices.

scholarly journals Xenon Flash Lamp Lift-Off Technology without Laser for Flexible Electronics

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 953
Author(s):  
Sang Il Lee ◽  
Seong Hyun Jang ◽  
Young Joon Han ◽  
Jun yeub Lee ◽  
Jun Choi ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Energy Intensity ◽  
Film Surface ◽  
Flash Lamp ◽  
Structural Deformation ◽  
Gravimetric Analysis ◽  
Xenon Flash Lamp ◽  
Optimum Energy ◽  
Lift Off ◽  
Xenon Flash

This study experimentally investigated process mechanisms and characteristics of newly developed xenon flash lamp lift-off (XF-LO) technology, a novel thin film lift-off method using a light to heat conversion layer (LTHC) and a xenon flash lamp (XFL). XF-LO technology was used to lift-off polyimide (PI) films of 8.68–19.6 μm thickness. When XFL energy irradiated to the LTHC was 2.61 J/cm2, the PI film was completely released from the carrier substrate. However, as the energy intensity of the XFL increased, it became increasingly difficult to completely release the PI film from the carrier substrate. Using thermal gravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR) and transmittance analysis, the process mechanism of XF-LO technology was investigated. Thermal durability of the PI film was found to deteriorate with increasing XFL energy intensity, resulting in structural deformation and increased roughness of the PI film surface. The optimum energy intensity of 2.61 J/cm2 or less was found to be effective for performing XF-LO technology. This study provides an attractive method for manufacturing flexible electronic boards outside the framework of existing laser lift-off (LLO) technology.

scholarly journals Structural and dielectric properties of some epiclon-based polyimide films

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Andreea Irina Cosutchi ◽  
Camelia Hulubei ◽  
Iuliana Stoica ◽  
Marius Dobromir ◽  
Silvia Ioan
Keyword(s):  
Chemical Structure ◽  
Electrical Conductance ◽  
Dielectric Constants ◽  
Isothermal Treatment ◽  
Cross Linking ◽  
Polyimide Films ◽  
Aromatic Polyimides ◽  
Low Dielectric ◽  
Dielectric Layers ◽  
High Roughness

AbstractSurface and electrical properties of two flexible and cross-linked epiclon based polyimide films were investigated. Surface tension measurements indicate an increased hydrophobicity due to both isothermal treatment - which induces imidization and cross-linking - and to the chemical structure, characterized by the different number of ether linkages in the polyimide backbone. Morphology of film surfaces, modified by plasma treatment, shows high roughness and, implicitly, improved adhesion, as required in electronics. The studied polyimides exhibit low dielectric constants and dielectric losses, comparatively to conventional aromatic polyimides. The electrical conductance and resistivity characteristics of these polymers recommend them as good insulators for dielectric layers in microelectronic applications.

Chemical structure of diamond-like carbon thin films

1990 ◽  
Vol 48 (4) ◽  
pp. 710-711
Author(s):  
N.-H. Cho ◽  
K.M. Krishnan ◽  
D.B. Bogy
Keyword(s):  
Electrical Resistivity ◽  
Chemical Structure ◽  
Diamond Like Carbon ◽  
Chemical Structures ◽  
Sputtering Power ◽  
Data Aquisition ◽  
Equilibrium Phases ◽  
Electron Energy Loss ◽  
Power Densities ◽  
Preparation Techniques

Diamond-like carbon (DLC) films have attracted much attention due to their useful properties and applications. These properties are quite variable depending on film preparation techniques and conditions, DLC is a metastable state formed from highly non-equilibrium phases during the condensation of ionized particles. The nature of the films is therefore strongly dependent on their particular chemical structures. In this study, electron energy loss spectroscopy (EELS) was used to investigate how the chemical bonding configurations of DLC films vary as a function of sputtering power densities. The electrical resistivity of the films was determined, and related to their chemical structure.DLC films with a thickness of about 300Å were prepared at 0.1, 1.1, 2.1, and 10.0 watts/cm2, respectively, on NaCl substrates by d.c. magnetron sputtering. EEL spectra were obtained from diamond, graphite, and the films using a JEOL 200 CX electron microscope operating at 200 kV. A Gatan parallel EEL spectrometer and a Kevex data aquisition system were used to analyze the energy distribution of transmitted electrons. The electrical resistivity of the films was measured by the four point probe method.

scholarly journals An Assessment of Surface Treatments for Adhesion of Polyimide Thin Films

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1955
Author(s):  
Marco Cen-Puc ◽  
Andreas Schander ◽  
Minerva G. Vargas Gleason ◽  
Walter Lang
Keyword(s):  
Flexible Electronics ◽  
Oxygen Plasma ◽  
Reactive Ion Etching ◽  
Peel Test ◽  
Scratch Test ◽  
Peel Strength ◽  
Surface Treatments ◽  
Oxygen Plasma Treatment ◽  
Polyimide Films ◽  
Ion Etching

Polyimide films are currently of great interest for the development of flexible electronics and sensors. In order to ensure a proper integration with other materials and PI itself, some sort of surface modification is required. In this work, microwave oxygen plasma, reactive ion etching oxygen plasma, combination of KOH and HCl solutions, and polyethylenimine solution were used as surface treatments of PI films. Treatments were compared to find the best method to promote the adhesion between two polyimide films. The first selection of the treatment conditions for each method was based on changes in the contact angle with deionized water. Afterward, further qualitative (scratch test) and a quantitative adhesion assessment (peel test) were performed. Both scratch test and peel strength indicated that oxygen plasma treatment using reactive ion etching equipment is the most promising approach for promoting the adhesion between polyimide films.

Double-network hydrogel with adjustable surface morphology and multifunctional integration for flexible strain sensors

Soft Matter ◽  
2021 ◽  
Author(s):  
Yang Yu ◽  
Fengjin Xie ◽  
Xinpei Gao ◽  
Liqiang Zheng
Keyword(s):  
Surface Morphology ◽  
Flexible Electronics ◽  
High Performance ◽  
Strain Sensors ◽  
Next Generation ◽  
Double Network ◽  
Conductive Hydrogels

The next generation of high-performance flexible electronics has put forward new demands to the development of ionic conductive hydrogels. In recent years, many efforts have been made toward developing double-network...

scholarly journals A Further Comprehensive Review on the Phytoconstituents from the Genus Erythrina

2020 ◽  
Vol 23 (1) ◽  
pp. 65-77 ◽  
Author(s):  
Mohammad Musarraf Hussain
Keyword(s):  
Chemical Structure ◽  
Biological Activities ◽  
Chemical Constituents ◽  
Pharmaceutical Journal ◽  
Significant Source ◽  
Comprehensive Review ◽  
Chemical Structures ◽  
Previous Review

Erythrina is a significant source of phytoconstituents. The aim of this review is to solicitude of classification, synthesis, and phytochemicals with biological activities of Erythrina. In our previous review on this genus (Hussain et. al., 2016a) fifteen species (Erythrina addisoniae, E. caribeae, E. indica, E. lattisima, E. melanacantha, E. mildbraedii, E. poeppigiama, E. stricta, E. subumbrans, E. veriagata, E. vespertilio, E. velutina, E. zeberi, E. zeyheri and E. americana) have been studied and 155 molecules with chemical structures were reported. A further comprehensive review was done upon continuation on the same genus and thirteen species (E. abyssinica, E. arborescens, E. berteroana, E. burttii, E. caffra, E. coralloids, E. crista-galli, E. fusca, E. herbaceae, E. lysistemon, E. mulungu, E. speciosa and E. tahitensis) of Erythrina have been studied and 127 compounds are reported as phytoconstituents with their chemical structure in this review. Erythrina crista-galli and E. lysistemon consist of highest number of chemical constituents. Bangladesh Pharmaceutical Journal 23(1): 65-77, 2020

scholarly journals In Vitro Effect of Replicated Porous Polymeric Nano-MicroStructured Biointerfaces Characteristics on Macrophages Behavior

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1913
Author(s):  
Luminita Nicoleta Dumitrescu ◽  
Madalina Icriverzi ◽  
Anca Bonciu ◽  
Anca Roșeanu ◽  
Antoniu Moldovan ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Photoelectron Spectroscopy ◽  
Polyvinylidene Fluoride ◽  
Surface Characteristics ◽  
Sem Analysis ◽  
Chemical Structures ◽  
Microstructured Surface ◽  
Inflammatory Conditions ◽  
Vitro Effect

In the last decades, optimizing implant properties in terms of materials and biointerface characteristics represents one of the main quests in biomedical research. Modifying and engineering polyvinylidene fluoride (PVDF) as scaffolds becomes more and more attractive to multiples areas of bio-applications (e.g., bone or cochlear implants). Nevertheless, the acceptance of an implant is affected by its inflammatory potency caused by surface-induced modification. Therefore, in this work, three types of nano-micro squared wells like PVDF structures (i.e., reversed pyramidal shape with depths from 0.8 to 2.5 microns) were obtained by replication, and the influence of their characteristics on the inflammatory response of human macrophages was investigated in vitro. FTIR and X-ray photoelectron spectroscopy analysis confirmed the maintaining chemical structures of the replicated surfaces, while the topographical surface characteristics were evaluated by AFM and SEM analysis. Contact angle and surface energy analysis indicated a modification from superhydrophobicity of casted materials to moderate hydrophobicity based on the structure’s depth change. The effects induced by PVDF casted and micron-sized reversed pyramidal replicas on macrophages behavior were evaluated in normal and inflammatory conditions (lipopolysaccharide treatment) using colorimetric, microscopy, and ELISA methods. Our results demonstrate that the depth of the microstructured surface affects the activity of macrophages and that the modification of topography could influence both the hydrophobicity of the surface and the inflammatory response.

scholarly journals A Review of Bacteriochlorophyllides: Chemical Structures and Applications

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1293
Author(s):  
Chih-Hui Yang ◽  
Keng-Shiang Huang ◽  
Yi-Ting Wang ◽  
Jei-Fu Shaw
Keyword(s):  
Solar Cell ◽  
Energy Harvesting ◽  
Chemical Structure ◽  
The Other ◽  
Dye Sensitized Solar Cell ◽  
Synthetic Route ◽  
Chemical Structures ◽  
Dye Sensitized ◽  
Heme Synthesis ◽  
Potential Applications

Generally, bacteriochlorophyllides were responsible for the photosynthesis in bacteria. Seven types of bacteriochlorophyllides have been disclosed. Bacteriochlorophyllides a/b/g could be synthesized from divinyl chlorophyllide a. The other bacteriochlorophyllides c/d/e/f could be synthesized from chlorophyllide a. The chemical structure and synthetic route of bacteriochlorophyllides were summarized in this review. Furthermore, the potential applications of bacteriochlorophyllides in photosensitizers, immunosensors, influence on bacteriochlorophyll aggregation, dye-sensitized solar cell, heme synthesis and for light energy harvesting simulation were discussed.

scholarly journals Influence of the chemical structure of cation surfactants on the wetting process of rock-forming minerals

2019 ◽  
Vol 55 (2) ◽  
pp. 142-148
Author(s):  
O. N. Opanasenko ◽  
N. P. Krutko ◽  
O. L. Zhigalova ◽  
O. V. Luksha
Keyword(s):  
Cationic Surfactants ◽  
Chemical Structure ◽  
Polyhydric Alcohol ◽  
Amino Groups ◽  
Interfacial Interactions ◽  
Alkyl Chains ◽  
Chemical Structures ◽  
Adsorption Interaction ◽  
Wetting Process ◽  
Steric Hindrances

Interfacial interactions of cationic surfactants of various chemical structures at the solution / finely dispersed mineral material (quartz and dolomite) interface were studied. It is established that the modification of the surfaces of quartz and dolomite with cationic surfactants leads to a change in the structure and radius of the capillaries due to the formation of adsorption-solvate shells. The hydrophobic ability of cationic surfactants is determined by the structure of the hydrophilic part of their molecules – the balance of amino groups in the alkyl chains and the absence of steric hindrances during adsorption interaction with the surface of mineral materials. The mixture of surfactants containing six amino groups and a polyhydric alcohol glycerin has an effective hydrophobic ability from both aqueous and highly mineralized solutions.

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