Effect of Hybrid Particles of Nano-Micron Sizes on Electrical Transport of Silver-Epoxy Composites (original) (raw)
Related papers
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.
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.%.
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.
Silver Particles on the Thermal and Electrical Characteristics of ECAs
International Journal of Recent Technology and Engineering (IJRTE), 2019
This study presents information on the thermal and electrical characteristics of silver (Ag) in range size of 2-3.5 μm and 80 nm in diameter. The present method demonstrates the thermal conductivity analysis and electrical resistivity influence by various particle content of Ag in Epoxy matrix for both micro and nano-sized. Furthermore, new technique of thermal properties and electrical resistivity observation is proposed by hybrid-sized analysis to characterize the effect of Ag size. The proposed hybrid-sized technique uses micro-and nano-sized particle ratios to generate the composite. The thermal and electrical resistivity characteristics of the epoxy composite-filled micro-, nano-, and hybrid-sized Ag particle are correlated with their morphology. The thermal conductivity of the electrically conductive adhesive sample is affected by Ag particle size. The micro-sized Ag particle is better filler than the nano-size Ag particle in increasing performance of the thermal conductivity in the matrix epoxy. The results of the electrical resistivity of micro-and nano-particles demonstrated similar characteristics that transition within insulator into conduction occurred at 6 vol%. While hybrid-sized systems shown decreasing in thermal conductivity performance when decreasing number micro-sized ratio. Other observation in hybrid-sized presented that the better performance of electrical conductivity has shown at 50:50 weight ratio.
Polymer, 2016
Diglycidyl ethers of bisphenol-A (DGEBA)/4,4 0 -diaminodiphenylmethane (DDM)/polyethersulphone (PES) blends were prepared as matrix resins for electrically conductive adhesives containing silver (Ag) fillers. The epoxy/PES blends formed co-continuous phase structures from initial homogeneous solutions via reaction-induced phase separation during the curing process. The Ag fillers were selectively localized in the epoxy-rich phases that had high affinity toward the surface of the Ag fillers. The co-continuous phase structures of the epoxy/PES blends acted as templates for the three-dimensional continuous structures of the Ag fillers. The self-assembled structures of the Ag fillers were connected in a continuous phase that possessed high electrical conductivity using a relatively small amount of Ag filler. In addition, the epoxy/PES/Ag adhesives had excellent shear adhesive strength. The fracture toughness of the epoxy/ PES blends was the source of the high adhesive strength.
Journal of Materials Science: Materials in Electronics, 2015
During the last two decades, considerable efforts have been made to explore new generations of interconnecting materials and printed lines to replace the traditionally used toxic lead-based solders in electronic packaging industries. Accordingly, development of electrically conductive adhesives (ECAs) with high electrical conductivity has become an interesting and urgent research venue in this field. Recently, the incorporation of nanosized conductive fillers inside the conventional formulation of ECAs has drawn considerable attention as an attempt to increase their electrical conductivity. In this article, we review different types of nanofillers that have been utilized inside the conventional ECAs to improve the electrical conductivity of ECAs. We focus on the synergetic effects of silver flakes and the nanofillers on electron transportation through the electrical network; the mechanisms of electrical conductivity enhancement are discussed. Special attention is given to the surface properties of the nanofillers and their corresponding influences on the filler-filler interaction, which has direct effect on the final electrical performance of the hybrid ECAs.
Conductivity enhancement of silver filled polymer composites through electric field alignment
Composites Science and Technology, 2012
We show how an alternating electric field can be used to align silver micron or sub-micron sized particles into microscopic wires in diverse polymer matrices based on the dielectrophoretic effect. The electric field is set by an electrode pair and the wires form conductive pathways through the matrix, bridging these electrodes electrically. The matrix is cured after alignment, locking wires in permanent pathways within the polymer. The wires are then characterized by ac impedance spectroscopy. The alignment can take place either in-plane or out-of-plane, and yields a directional conductivity in the alignment direction parallel to the electric field lines. The samples can be centimeters wide containing thousands of wires in parallel, but even an individual wire can be grown and controlled. The initial mixture contains less than 1 vol.% of silver and is an electrical insulator. The bulk conductivity enhancement, due to the alignment, may be 5 orders of magnitude, typically from 1 Â 10 À5 S/m to 1 S/m as the particle alignment converts the sample conductivity from polymer dominated to silver dominated. For the aligned isolated silver wires, the jump in conductivity, confined to the volume filled by the wire can be seen to be as high as 9-10 orders of magnitude, resulting in conductivities as high as 1 Â 10 5 S/m, thus approaching those of pure metal. This technique offers new ways on how e.g. conducting polymer composites and conducting glues could be produced.
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.
2021
An attempt was made in this work to decorated carbon nanotubes(CNTs) in a polymer matrix using biosynthesized silver nanoparticles (GAgNPs) using Cashew leaves as a reduction agent. The new hybrid epoxy-CNTs+ GAgNPs composites were produced by modified solution-stir-cast method. The microstructure, thermal properties, strength, and electrical conductivity of the produced composites were determined. The electrical conductivity of the epoxy polymer has been enhanced from 5.6x10-13S/cm to 4.80x10-3S/cm for epoxy-0.5%CNTs and 9.1x10-3S/cm epoxy-0.5%CNTs-0.5%GAgNPs. GAgNPs was effective used to improve the strength of conducting epoxy-CNTs for electronic devices. The addition of CNTs and GAgNPs to epoxy increases the glass transition temperature. It was established that GAgNPs can be promising materials to enhanced thermal conductivity, strength, electrical conductivity of epoxy-CNTs and recover the potential reduction for electronic devices application.
Testing of techniques for improvement of conductivity of electrically conductive adhesives
2008 2nd Electronics Systemintegration Technology Conference, 2008
The paper presents methods, which have been used for improvement of electrical conductivity of electrically conductive adhesives with isotropical electrical conductivity. Conductivity level depends, among other things, on level of aggregation of filler particles. The research has been focused on improvement of electrical properties by better aggregation of filler particles in adhesive. Following methods have been tested with the goal to support aggregation: ultrasound mixing for 60s, rotary mixing for 60 s, and addition of a small amount of AgN0 3. The goal of addition of this salt has been to decrease Coulomb forces between particles of filler. Four types of formulations have been used for experiments. One-component formulations: adhesives bisphenol epoxy resin with 75 % (wt.) silver flakes, bisphenol epoxy resin with 75 % (wt.) silver flakes + 10 % (wt.) silver nanoparticles, bisphenol epoxy resin with 65 % (wt.) silver flakes + 20 % (wt.) silver nanoparticles. Two component formulation: bisphenol epoxy resin with 55 % (wt.) silver flakes. It has been found that ultrasound mixing has low influence only to the value of the electrical conductivity of adhesive, rotary mixing before application of the adhesive improves electrical conductivity significantly; addition of AgN0 3 into the adhesive has improved electrical conductivity of two formulations and has had almost no effect for two other formulations. As a part of this work the course of electrical conductivity of adhesives during the curing time has also been investigated.