• Design & Manufacturing
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• v.6 no.1
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• pp.95-100
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• 2012

In this study, a novel Cu composite sheet with embedded high electric conduction path was developed as another alternative for the interconnect materials possessing high electrical conductivity as well as high strength. The Cu composite sheet was fabricated by forming Ag conduction paths not within the interior but on the surface of a high strength Cu substrate by damascene electroplating process. As a result, the electrical conductivity increased by 40% thanks to mesh type Ag conduction paths, while the ultimate tensile strength decreased by 20%. The interfacial fracture resistance of Cu composite sheet prepared by damascene electroplating increased by above 50 times compared to Cu composite sheet by conventional electroplating. For feasibility test for practical application, a leadframe for LED module was manufactured by a progressive blanking and piercing processes, and the blanked surface profile was evaluated as a function of the volume fraction of Ag conduction paths. As Ag conduction path became finer, pressing formability improved.

• Elastomers and Composites
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• v.57 no.1
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• pp.1-8
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• 2022

In this study, the photo-deposition method was used to introduce Ag onto the surface of TiO₂ to synthesize an Ag-TiO₂ composite. The effects of the varying amounts of AgNO₃ precursor and annealing time periods on the Ag content in the composites, as well as their antibacterial characteristics under visible light conditions were studied. SEM analysis revealed the spherical morphology of the Ag-TiO₂ composite. Compared with TiO₂, the Ag particles were too small to be observed. An XPS analysis of the Ag-TiO₂ surface confirmed the Ag content and showed the peak intensities for elements such as Ag, Ti, O, C, and Si. The highest Ag content was observed when 33.3 wt.% of AgNO₃ and an annealing time of 6 h were employed; this was the optimum annealing time for Ti-Ag-O bonding, in that the lowest number of O bonds and the highest number of Ag bonds were confirmed by XPS analysis. Superior antibacterial properties against Bacillus and Escherichia coli, in addition to the widest inhibition zones were exhibited by the Ag-TiO₂ composite with an increased Ag content in a disk diffusion test, the bacterial reduction rate against Staphylococcus aureus and Escherichia coli being 99.9%.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2969-2973
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• 2014

A new process to fabricate a composite LSCF-Ag cathode material for SOFCs by electron beam (e-beam) irradiation process has been suggested for operation under intermediate temperature range of $600-700^{\circ}C$. A composite LSCF-Ag cathode with uniformly coated Ag nanoparticles on the surface of the LSCF material was prepared by a facile e-beam irradiation method at room temperature. The morphology of the composite LSCF-Ag material was analyzed using a TEM, FE-SEM, and EDS. The prepared composite LSCF-Ag material can play a significant role in increasing the electro-catalytic activities and reducing the operating temperature of SOFCs. The performance of a tubular single cell prepared using the composite LSCF-Ag cathode, YSZ electrolyte and a Ni/YSZ anode was evaluated at reduced operating temperature of $600-700^{\circ}C$. The micro-structure and chemical composition of the single cell were investigated using a FE-SEM and EDS.

• Journal of Powder Materials
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• v.19 no.6
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• pp.416-423
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• 2012

This paper introduces an effect of a preparing $ZrO_2$-Ag composite on its mechanical properties and microstructure. In present study, $ZrO_2$-Ag was prepared by reduction-deposition route and wetting dispersive milling method, respectively. Two type of Ag powders (nano Ag and micron Ag size, respectively) were dispersed into $ZrO_2$ powder during wetting dispersive milling in D.I. water. Each sample was sintered at $1450^{\circ}C$ for 2hr in atmosphere, and then several mechanical tests and analysis of microstructure were carried out by bending test, hardness, fracture toughness and fracture surface microstructure. As for microstructure, the Ag coated $ZrO_2$ showed homogeneously dispersed Ag in $ZrO_2$ in where pore defect did not appear. However, $ZrO_2$-nano Ag and $ZrO_2$-micro Ag composite appeared Ag aggregation and its pore defect, which carried out low mechanical property and wide error function value.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.3
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• pp.39-44
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• 2015

We investigated the effect of CNT-Ag composite pad on the contact resistance of flip-chip joints, which were formed by flip-chip bonding of Cu/Au chip bumps to Cu substrate metallization using anisotropic conductive adhesive. Lower contact resistances were obtained for the flip-chip joints which contained the CNT-Ag composite pad than the joints without the CNT-Ag composite pad. While the flip-chip joints with the CNT-Ag composite pad exhibited average contact resistances of $164m{\Omega}$, $141m{\Omega}$, and $132m{\Omega}$ at bonding pressures of 25 MPa, 50 MPa, and 100 MPa, the flip-chip joints without the CNT-Ag composite pad had an average contact resistance of $200m{\Omega}$, $150m{\Omega}$, and $140m{\Omega}$ at each bonding pressure.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.4
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• pp.17-23
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• 2013

As a basic research to develop stretchable electronic packaging technology, CNT-Ag composite pads were formed on top of Cu/Sn chip bumps and flip-chip bonded using anisotropic conductive adhesive. Average contact resistances of the flip-chip joints were measured with respect to bonding pressure and presence of the CNT-Ag composite pads. When Cu/Sn chip bumps with CNT-Ag composite pads were flip-chip bonded to substrate Cu pads at 25MPa or 50 MPa, contact resistance was too high to measure. The specimen processed by flip-chip bonding the Cu/Sn chip bumps with CNT-Ag composite pads to the substrate Cu pads exhibited an average contact resistance of $213m{\Omega}$. On the other hand, the flip-chip specimens processed by bonding Cu/Sn chip bumps without CNT-Ag composite pads to substrate Cu pads at 25MPa, 50MPa, and 100MPa exhibited average contact resistances of $370m{\Omega}$, $372m{\Omega}$, and $112m{\Omega}$, respectively.

• Korean Journal of Materials Research
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• v.18 no.7
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• pp.389-393
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• 2008

Nano-sized $TiO_2$-60 wt% SrO composite powders were synthesized by a sol-gel method using titanium isopropoxide and $Sr(OH)_2\;{\cdot}\;8H_2O$ as precursors. 3, -5, -7 wt%Ag spot-coated $TiO_2$-60 wt% SrO composite powders were synthesized by a Ag electroless deposition method using $TiO_2$-60 wt% SrO composite powders calcined at $1050^{\circ}C$, which mainly exhibited the $SrTiO_3$phase. However, a small number of rutile $TiO_2$, $Sr_2TiO_4$ and $SrO_2$ phases were also detected. In the Ag spot-coated powders synthesized by electroless deposition, nano-sized particles about 5-25 nm in diameter adhered to the $TiO_2$-60 wt% SrO composite powders. The photocatalytic activity of Ag spot-coated $TiO_2$-SrO and $TiO_2$-SrO composite powders for degradation of phenol showed that all of $TiO_2$-SrO composite powders were highly active under UV light irradiation. 7 wt%Ag spot-coated $TiO_2$-60wt.%SrO composite powders had a relatively higher photocatalytic activity than did $TiO_2$-SrO composite powders under visible light.

• Journal of the Semiconductor & Display Technology
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• v.19 no.4
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• pp.6-10
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• 2020

The silver nanowires (AgNWs) were synthesized by the conventional polyol process, which revealed 25 ㎛ and 30 nm of average length and diameter, respectively. The synthesized AgNWs were applied to the CdSe/CdZnS quantum dot (QD) based transparent light-emitting device (LED). The device using a randomly networked AgNWs electrode had some problems such as the high threshold voltage (for operating the device) due to the random pores from the networked AgNWs. As a method of improvement, a composite electrode was formed by overlaying the ZnO:Ga on the AgNWs network. The device used the composite electrode revealed a low threshold voltage (4.4 Vth) and high current density compared to the AgNWs only electrode device. The brightness and current density of the device using composite electrode were 55.57 cd/㎡ and 41.54 mA/㎠ at the operating voltage of 12.8 V, respectively, while the brightness and current density of the device using (single) AgNWs only were 1.71 cd/㎡ and 2.05 mA/㎠ at the same operating voltage. The transmittance of the device revealed 65 % in a range of visible light. Besides the reliability of the devices was confirmed that the device using the composite electrode revealed 2 times longer lifetime than that of the AgNWs only electrode device.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1054-1055
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• 2006

Bend tests were performed at temperatures between 77 and 473K for W-19vol%Cu, W-22vol%Ag and W-19vol%(BAg-8) composites. Yield and maximum strengths and ductility of the composite were discussed in terms of microstructure and fractography. Results are summarized as follows. (1) Almost no difference was recognized in yield strength between the composites. In contrast, a large difference was recognized in maximum strength and ductility between the composites. (2) Inferior mechanical properties of W-Ag composite to W-Cu composite are attributed to heterogeneous distribution of Ag-phases, whilst inferior mechanical properties of W-(BAg-8) composite to W-Cu composite are attributed to large pores at grain boundaries.

• Membrane Journal
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• v.28 no.4
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• pp.260-264
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• 2018

Poly (ethylene oxide) (PEO)/Ag nanoparticles (AgNPs)(precursor : $AgBF_4$)/p-benzoquinone (p-BQ) composite membrane was prepared for olefin/paraffin separation. As a result, the performance of composite membrane was observed to be maintained at selectivity of 10 and permeance of 15 GPU up to 100 hours. The performance of the membrane was maintained for 100 hours was attributable to that Ag ions could be converted into stable Ag NPs by addition of p-BQ. Furthermore, the surface was partially polarized by the electron acceptor p-BQ, resulting in the formation of olefin carrier. In this study, since the cost of $AgBF_4$ used as a precursor of Ag NPs was relatively higher, $AgNO_3$ was utilized. As a result, it was confirmed that $AgNO_3$ couldn't show the stable formation of nanoparticle, resulting in the poor separation performance.