Self-assembled three-dimensional structure of epoxy/polyethersulphone/silver adhesives with electrical conductivity (original) (raw)
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2011
In this study, the effect of amine adduct powder (AAP) on the electrical conductivity, thermal expansion, and flexural modulus of one-part system conductive adhesives are investigated. One-part system conductive adhesives are prepared using two types of silver (silver A and silver B) and different percentage of filler loadings, 10 vol.%-40 vol.%. Silver A adhesive systems exhibit higher electrical conductivity with lower percolation thresholds, high flexural moduli, and low coefficients of thermal expansion (CTE) compared silver B adhesive systems. A comparison of the electrical conductivity and thermal expansion properties of the one part and two-part of silver A adhesives system is undertaken. The one-part silver A adhesives system shows high electrical conductivity and low CTE values compared to the two-part system. This is due to the higher cross linking density of the one-part system compared to that of the two-part system.
Synthetic Metals, 2004
Electrical conductivity and percolation concentrations of epoxy and polyurethane (PU) resins filled with Ag-coated particles and short fibers were studied in this paper. Percolation concentrations were determined to be as follows: 29 vol.% for epoxy/Ag-coated fibers and PU/Ag-coated particles and fibers and 28 vol.% for epoxy/Ag-coated particles. The highest values of electrical conductivity were found for PU/Ag-coated fibers.
Journal of Applied Polymer Science, 2014
In this study, a dual-microcapsule epoxy-amine self-healing concept is used for electrically conductive adhesives (ECAs). It provides the ECA samples with the ability to recover mechanical and electrical properties automatically. Epoxy and amine microcapsules were prepared and incorporated into silver/epoxy ECAs. The healing efficiency and bulk resistivity of the undamaged, damaged, and healed specimens were measured, respectively. The optimal loading of the epoxy and amine microcapsules is 6 wt % (weight ratio 1.05), and the bulk resistivity of the healed specimens is 3.4 3 10 23 X cm.
Improving the electrical properties of structural epoxy resin adhesives
International Journal of Adhesion and Adhesives, 1991
The role played by metallic fillers in improving the electrical conductivity of structural epoxy resin adhesives has been investigated by adding powdered filler materials having different particle sizes in different weight percentages. Fibrous fillers, effectively oriented as well as randomly chopped, have also been studied. Results showed that the randomly chopped fibres are superior in improving the electrical conductivity of structural epoxy resin adhesives. However, powdered fillers are better at enhancing the mechanical strength of these adhesives.
Synthesis of conductive adhesives based on epoxy resin and polyaniline.DBSA
Electrically conductive adhesives based on epoxy-anhydride systemcontaining polyaniline (PAni) doped with dodecylbenzenesulfonic acid (DBSA) have been successfully developed and characterized. The blends were prepared by physical mixing and by in situ polymerization of aniline within epoxy matrix. The in situ polymerization procedure contributes for the formation of a conducting pathway with lower amount of PAni.DBSA. A conductivity as low as 10−3 Scm−1 with 12wt% of PAni and excellent adheion properties were achieved with these systems. The microstructure of the conductive adhesives was studied by means of scanning electron microscopy (SEM). In the case of blends prepared by in situ poly- merization, PAni.DBSA is dispersed within the epoxy matrix in the form of microtubules. Dielectrical properties as a function of frequency and temperature have also indicated a great interaction between polyaniline and epoxy matrix by in situ polymerization procedure.
Journal of The Electrochemical Society, 2014
Silver-plated graphite powder, poly(3,4-ethylenedioxythiolphene):poly(styrenesulfonate) (PEDOT:PSS), and organic additives were employed to reduce the electrical resistivities of epoxy-based adhesives. A novel silver self-activated electroless deposition using conductive graphite particles as filler in electrically conductive adhesives (ECAs) was investigated to develop high-performance ECAs with low silver content. Adding silver-plated graphite powders to the conductive adhesives reduced their electrical resistivities by at least two orders of magnitude compared with those filled with graphite powders only. The silver content of the adhesive with PEDOT:PSS decreased to 24.7 wt%, and its resistivity was 1.2 × 10 −3 cm. The best electrical resistivity of the epoxy-based conductive adhesives with 70 wt% silver-plated graphite powders was 4.36 × 10 −4 cm. The weight percentage of silver in this epoxy-based adhesive decreased to 43.3 wt%, which is much lower than that of conventional silver conductive adhesives.
2011
Epoxy composites filled with nano-and microsized silver (Ag) particulate fillers were prepared and characterized based on flexural properties, coefficient of thermal expansion, dynamic mechanical analysis, electrical conductivity, and morphological properties. The influences of these two types of Ag fillers, especially in terms of their sizes and shapes, were investigated. Silver nanoparticles were nano-sized and spherical, while silver flakes were micron-sized and flaky. It was found that the flexural strength of the epoxy composite filled with silver flakes decreased, while the flexural strength of the epoxy composite filled with silver nanoparticles showed an optimum value at 4 vol.% before it subsequently dropped. Both silver composites showed improvement in flexural modulus with increasing filler loads. CTE value indicated significant decrements in filled samples compared to neat epoxy. Results on the electrical conductivity of both systems showed a transition from insulation to conduction at 6 vol.%.
EFFECTS OF POLYANILINE FILLER ON THE SHEAR STRENGTH OF SILVER-POLYANILINE-EPOXY ADHESIVE
Electrically Conductive Adhesives (ECAs) are widely applied in electronic packaging such as solder less interconnections, heat dissipation and component repair. This research focuses on the effects of polyaniline filler percentage in the silver-polyaniline epoxy conductive adhesive. Conductive adhesives with different polyaniline filler concentrations were prepared, so as to check on how the different filler concentrations affect the shear strength of the ECAs. Silver concentration was kept constant, but the polyaniline concentration was varied between 3-10%. The shear strength of the adhesive was measured using the universal tensile machine and the results showed that, more the filler loading is increased, less the adhesive strength exhibited by the composite. The research also shows the synthesis of the main filler silver particles by chemical reduction method and also the synthesis of the co-filler polyaniline by chemical method and both UV (Ultraviolet) and SEM (Scanning Electron Microscope) characterizations were conducted. Keywords: Electrically Conductive Adhesives, Filler Loading, Silver Particles, Polyaniline Particles, Shear Strength
Electrically conductive adhesive filled with mixture of silver nano and microparticles
2008
Electrically conductive adhesive with isotropical electrical conductivity modified with addition of silver nanoparticles has been investigated. The electrical resistance, nonlinearity of a current vs. voltage characteristic and the tensile strength of adhesive joints formed of this adhesive have been measured. The specimens have also been aged at the temperature of 125°C and at the combined climate 80°C/80 % relative humidity for 700 hours. It has been found that silver nanoparticles added into the electrically conductive adhesive cause decrease of its conductivity, increase of its nonlinearity and increase of the tensile strength.
Journal of Materials Science: Materials in Electronics, 2020
In the past few decades, increasing demands for electrically conductive adhesives (ECAs) have led to growing interest in the design and development of innovative strategies to obtain materials with synergetic or complementary properties for various industrial as well as biomedical applications. In this context, the replacement of traditional tin/lead (Sn/Pb) solders due to their corrosion, low strength of joints, solder joint fatigue, stress-induced cracking within the interconnect, as well as environmental issues are attracted a great deal of interests, especially in industrial committees. The significant progress in polymer science as well as the advent of nanotechnology, have been led to design and development of alternative materials with higher performance over conventional adhesives. On the other hand, intrinsically conductive polymers (ICPs) offer promising materials for the replacement or reducing the content of metallic fillers (e.g., silver, gold, nickel, or copper) in ECAs due to some disadvantages of metallic fillers. For the first time, an overview of the recent progress in the design, fabrication, and applications of the ECAs based on ICPs is presented.