Lead Free Paste with under 3um Solder Particles for Fine Pitch C4 bumping and pre-coating solder applications

2013 ◽  
Vol 2013 (DPC) ◽  
pp. 000862-000889
Author(s):  
Hironori Uno ◽  
Masayuki Ishikawa ◽  
Akihiro Masuda ◽  
Hiroki Muraoka ◽  
Kanji Kuba
Keyword(s):  
Chemical Reduction ◽  
Average Particle Size ◽  
Average Particle ◽  
Solder Paste ◽  
Chemical Reduction Method ◽  
Property Evaluation ◽  
Fine Pitch ◽  
Solder Bumps ◽  
Size Of Particles ◽  
Average Size

The work to be detailed in this paper is our development of 96.5mass%Sn-3.0mass%Ag-0.5mass%Cu fine solder particles with an average particle size of under 3um (D50), using a chemical reduction method. An evaluation was conducted on the properties of the particles. The average size of particles appeared to be under 3um with a higher yield compared to particles using the conventional gas atomization method. The melting temperature of fine solder particles using this method was its eutectic temperature, which is same as using the gas–atomized particles. 120um pitch solder bumps from the solder paste using the above mentioned fine solder particles were created on the substrate. As a result of property evaluation, it was turned out that the solder paste created a superior printing shape and coplanarity compared to the conventional paste with gas-atomized particles. In order to investigate the superior printing property generated by the paste with fine solder particles, the rheology of the paste was evaluated.It was verified that the anisotropic shape of particles has contributed to prevent the printed paste from slumping, which has resulted in the improvement of printed shape. It also shows that the filling characteristic of the paste was improved by the smaller particles and the better coplanarity was observed. The importance of finer solder particles for finer pitch assembly will be presented.

Synthesis and Consolidation of Nano-Sized NiCo Powder by Powder Technology Rout

2007 ◽  
Vol 561-565 ◽  
pp. 1425-1428 ◽  
Author(s):  
W.M. Daoush
Keyword(s):  
Composite Powder ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Complexing Agent ◽  
Average Particle ◽  
Chemical Reduction Method ◽  
Homogeneous Microstructure ◽  
Electrical And Magnetic Properties ◽  
Saturation Induction ◽  
Metallic Salt

Nano sized Co-20wt%Ni composite powder was synthesized by electroless chemical reduction method using metallic salt precursors and hypophosphite as a reducing agent in alkaline tartarate bath as a complexing agent. The synthesized powder provide better sinterability, mechanical, electrical and magnetic properties with homogeneous microstructure. The nano-sized powder could be obtained, which have the average particle size of 40 nm, with a saturation magnetization (Bs ) of 97.95 which was increased by heat treatments of powder in hydrogen to 127 emu/g due to the exclusion of the precipitated phosphrous in the composite powder. The powder underwent cold compaction at 600 Mpa and sintering at 1050 oC for 30 min. The saturation induction for the sintered material of 149.3 emu/g higher than the synthesized powder and has electrical resistivity value of 7.6 μcm.

Electrical Properties of Silver Paste Prepared from Nanoparticles and Lead-Free Frit

2007 ◽  
Vol 7 (11) ◽  
pp. 3917-3919 ◽  
Author(s):  
Sung Hyun Park ◽  
Dong Seok Seo ◽  
Jong Kook Lee
Keyword(s):  
Silver Nanoparticles ◽  
Electrical Properties ◽  
Screen Printing ◽  
Chemical Reduction ◽  
Silver Powder ◽  
Average Particle Size ◽  
Average Particle ◽  
Chemical Reduction Method ◽  
Silver Paste ◽  
Thermal And Electrical Properties

Recently, PbO containing glass systems in commercial silver paste have been used due to their low glass transition temperature, good thermal and electrical properties. However, PbO is a hazardous material to both health and the environment. In this study, Pb-free silver paste was prepared by mixing commercial silver powder and silver nanoparticles. The commercial powder has an average particle size of 1.6 μm. The silver nanoparticles with particles size of 20–50 nm were synthesized by a chemical reduction method using surfactant. Pb-free frit was added into the mixed silver powder as the amounts of 3, 6 and 9 wt%. Using the obtained paste, thick films were fabricated by a screen printing on alumina substrate and the films were fired at temperature from 400 to 550 °C. The films had thickness of 6–11 μm and sheet resistivity of about 4–11 μΩ cm.

scholarly journals Synthesis and Characterization of Sn/Ag Nanoparticle Composite as Electro-Catalyst for Fuel Cell

2021 ◽  
Vol 1 (1) ◽  
pp. 12-21
Author(s):  
Tan Wei Kang ◽  
Siti Husnaa Mohd Taib ◽  
Pooria Moozarm Nia ◽  
Mikio Miyake ◽  
Kamyar Shameli
Keyword(s):  
Chemical Reduction ◽  
Sodium Succinate ◽  
Average Particle Size ◽  
Average Particle ◽  
Protective Agent ◽  
Ag Nanoparticle ◽  
Chemical Reduction Method ◽  
Sn Nanoparticle ◽  
Composite Samples

In this research, Sn/Ag nanoparticle composite was produced by using chemical reduction method with the aids of sodium borohydride as reducing agent and sodium succinate as protective agent. The XRD, EDX, and TEM analyses showed that the Sn/Ag nanoparticle composite was formed with an average particle size of 4.37 + 0.44 nm. For the application, LSV analysis was done on Sn nanoparticle and Sn/Ag nanoparticle composite samples, and the analysis showed current produced from Sn/Ag nanoparticle composite (4.10 × 10-6 A) is higher than Sn nanoparticle (3.47 × 10-6 A) at the potential of -0.83V.

scholarly journals Solar Energy as Renewable Energy for the Degradation of Pollutants using High Active Ag@TiO2/α-Fe2O3 Ternary Nanocomposite Photocatalyst

2021 ◽  
Author(s):  
Nesrine Ben Saber
Keyword(s):  
Reduction Method ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Visible Region ◽  
Metallic Silver ◽  
Average Particle ◽  
Chemical Reduction Method ◽  
Ternary Nanocomposite ◽  
Photo Response ◽  
Chemical Procedure

Abstract In this work, ternary Ag@TiO2/α-Fe2O3 nanocomposite were synthesized via solvothermal chemical reduction method using N,N-dimethylformamide (DMF) as solvent and reducing agent. The chemical procedure involves the use of only metals precursors without the need to use any other surfactants or capping agents. Physicochemical properties of the designed photocatalyst are found by means of various modern techniques. XRD data confirmed the high crystallinity of the obtained ternary nanocomposite. On the other hand, using TEM and HRTEM instruments, the shape and morphology of the Ag@TiO2/α-Fe2O3 nanocomposite were found to be spherical with an average particle size of 150 nm. The UV-Vis measurement shows that Ag@TiO2/α-Fe2O3 as photocatalyst exhibited good photo response in the visible region. The effect of preparation method and the performance of the designed photocatalyst were evaluated by photodegradation measurements of MB under visible light irradiation. We observed that the combination of metallic silver nanoparticles (AgNPs) and hematite iron oxide (α-Fe2O3) with titanium dioxide (TiO2) enhance the photocatalytic activity of the ternary Ag@TiO2/α-Fe2O3 photocatalyst compared to bare TiO2 suggesting its potential for many purification applications.

Super Fine Lead-Free Solder Powder for Fine Pitch Bump Applications

2012 ◽  
Vol 2012 (DPC) ◽  
pp. 001016-001038
Author(s):  
Ryuji Uesugi ◽  
Hironori Uno ◽  
Masayuki Ishikawa ◽  
Akihiro Masuda ◽  
Hiroki Muraoka ◽  
...  
Keyword(s):  
Chemical Reduction ◽  
Fine Powder ◽  
Lead Free ◽  
High Yield ◽  
Solder Paste ◽  
Fine Pitch ◽  
Solder Bumps ◽  
Wet Chemical ◽  
Free Solder ◽  
Near Future

We have successfully developed super fine lead-free and low alpha solder powder, which contains more than two elements by the method of wet chemical reduction. The size (D50) of super fine powder is around 2–3 micrometer to meet finer pitch assembly in the near future. This new method made it available to synthesize various compositions of solder powder like Sn-Ag, Sn-Cu, Sn-Ag-Cu, etc. Also, this method achieves very high yield compared to a gas atomization method. A solder paste for printing method composed of the fine solder powder has a superior printing ability because of the unique powder shape. The powder shows anisotropic shape, and it can make printed figure excellent after printing without bridge and coplanarity issues for finer pitch applications. With our super fine solder paste, we will be ready for <100um pitch of solder bumps which will come in a few years. Furthermore, the super fine powder is applied to the Cu pad pre-coat. The solder paste for pre-coat composed of the super fine powder shows an excellent coverage and solders flatness on the outer pad after reflow.

Simple One-Step Synthesis of Uniform Disperse Copper Nanoparticles

2005 ◽  
Vol 879 ◽  
Author(s):  
Chunwei Wu ◽  
Brian P. Mosher ◽  
Taofang Zeng
Keyword(s):  
Ascorbic Acid ◽  
Copper Nanoparticles ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Average Particle ◽  
Face Centered Cubic ◽  
Chemical Reduction Method ◽  
Disperse Copper ◽  
One Step ◽  
Face Centered

AbstractIn this paper, we describe a simple and rapid solution-phase chemical reduction method with no inert gas protection, for preparing stable copper nanoparticle colloid with average particle size of 3.4 nm and narrow size distribution. In our synthesis route, ascorbic acid, natural vitamin C (VC), serves as both a reducing agent and an antioxidant to reduce copper salt precursor and effectively prevent the general oxidation process occurring to the newborn nanoparticles. XRD and UV/vis confirm the formation of pure face-centered cubic (fcc) copper nanoparticles and the excellent antioxidant ability of ascorbic acid.

scholarly journals RADIATION SYNTHESIS OF SILVER NANOPARTICLES/CHITOSAN AGAINST Corynespora cassiicola CAUSING LEAF FALL DISEASE ON RUBBER TREES

2018 ◽  
Vol 55 (1A) ◽  
pp. 45
Author(s):  
Le Thi An Nhien
Keyword(s):  
Silver Nanoparticles ◽  
Nitrate Solution ◽  
Average Particle Size ◽  
Silver Nitrate Solution ◽  
Average Particle ◽  
In Vitro Test ◽  
Corynespora Cassiicola ◽  
Size Of Particles ◽  
Average Size

In this study, silver nanoparticles (AgNPs) were prepared by gamma rays irradiation of 1.0, 2.5, 5.0 and 10 mM silver nitrate solution using chitosan as a stabilizer. UV spectra, morphology and size of AgNPs irradiated at different doses were characterized by using UV-vis spectrophotometer and TEM images. The obtained results indicated that the average size of AgNPs increased by the increase of silver concentration in irradiated solution or the degree of acetylation of chitosan, while the increase of chitosan concentration was found to be a functional key for reducing the average size of particles in AgNPs product. In vitro test, AgNPs inhibited the growth of Corynespora cassiicola. In particularly, the inhibitory efficiency of AgNPs on the growth of C. cassiicola on rubber leaf extract media increased from 52.1 to 100 % when the average particle size of particles in AgNPs product decreased from 15 to 5 nm at the concentration of 50 ppm. In addition, the increase of AgNPs concentration from 10 to 90 ppm also enhanced the antifungal activity to be from 6.3 to 100 %, respectively. It suggests that the silver nanoparticles/chitosan (AgNPs/chitosan) synthesized by γ-rays irradiation method is a very promising fungicidal product applying for treating C. cassiicola, a serious pathogen fungus on rubber trees.

scholarly journals A study of chewing during eating in the cow

1966 ◽  
Vol 20 (1) ◽  
pp. 13-23 ◽  
Author(s):  
J. Gill ◽  
R. C. Campling ◽  
D. R. Westgarth
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Average Particle ◽  
Jaw Movements ◽  
Mean Particle Size ◽  
The Mean ◽  
Preliminary Study ◽  
Size Of Particles ◽  
Average Size ◽  
Made In

1. A preliminary study was made of chewing duringeating with a total of sixcows with rumen fistulas, given diets of hay or herbage. A sieving technique was used to determine the size of particles of food swallowed at intervals throughout the eating period. The number of jaw movements, number and weight of the swallowed food boluses and the time spent eating were measured with each diet.2. The mean particle size of hay contained in a bolus collected at the cardia varied between individual cows from 1602 μm to 1244 μm. Boluses swallowed in the first few minutes of eating contained particles of a larger average size than those at any other time during the meal. Also, the rate of swallowing boluses of food was much faster at the beginning of a meal and the weight of boluses smaller than at any other time. The frequency of jaw movements did not vary appreciably during a meal.3. Increasing the amount of hay given to the cows by 50 % or giving a different hay did not cause any significarlt alteration in the average size of particles of swallowed hay, and changes in the rate of swallowing boluses, or in, the rate of jaw movements and the size of boluses were not very marked.4. With a diet of herbage, boluses were swallowed rapidly and the average particle size of swallowed food was larger than that of hay. Also, there were slightly more jaw movements per min and larger boluses than with hay.5. The observations made in the study are discussed in relation to possible factors that determine the particle size of swallowed food.

scholarly journals Effect of the polymeric coating over Fe3O4 particles used for magnetic separation

2010 ◽  
Vol 8 (5) ◽  
pp. 1041-1046 ◽  
Author(s):  
Raúl Reza ◽  
Carlos Martínez Pérez ◽  
Claudia Rodríguez González ◽  
Humberto Romero ◽  
Perla García Casillas
Keyword(s):  
Particle Size ◽  
Magnetite Nanoparticles ◽  
Average Particle Size ◽  
Spherical Shape ◽  
Polymeric Coating ◽  
Average Particle ◽  
Synthesis Conditions ◽  
Aging Conditions ◽  
Magnetite Particles ◽  
Average Size

AbstractIn this work, the synthesis of magnetite nanoparticles by two variant chemical coprecipitation methods that involve reflux and aging conditions was investigated. The influence of the synthesis conditions on particle size, morphology, magnetic properties and protein adsorption were studied. The synthesized magnetite nanoparticles showed a spherical shape with an average particle size directly influenced by the synthesis technique. Particles of average size 27 nm and 200 nm were obtained. When the coprecipitation method was used without reflux and aging, the smallest particles were obtained. Magnetite nanoparticles obtained from both methods exhibited a superparamagnetic behavior and their saturation magnetization was particle size dependent. Values of 67 and 78 emu g−1 were obtained for the 27 nm and 200 nm magnetite particles, respectively. The nanoparticles were coated with silica, aminosilane, and silica-aminosilane shell. The influence of the coating on protein absorption was studied using Bovine Serum Albumin (BSA) protein.

scholarly journals Effect of Nanosized Colloidal Copper on Cotton Fabric

2010 ◽  
Vol 5 (3) ◽  
pp. 155892501000500 ◽  
Author(s):  
D.P. Chattopadhyay ◽  
B.H. Patel
Keyword(s):  
Particle Size ◽  
Cotton Fabric ◽  
Colloidal Solution ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Particle Size Analysis ◽  
Nano Particles ◽  
Size Analysis ◽  
Average Particle ◽  
Sem Images

This research deals with the synthesis of nanosized copper as colloidal solution and its application to cotton fabric. Copper nano colloids were prepared by chemical reduction of copper salt using sodium borohydride as reducing agent in presence of tri-sodium citrate. The size and size distribution of the particles were examined by particle size analyzer and the morphology of the synthesized particles was examined by SEM and AFM techniques. X-ray fluorescence spectroscopy detected the presence of copper in the treated fabric. The results of particle size analysis showed that the average particle size varied from 60 nm to 100 nm. The nano copper treated cotton was subjected to soil burial test for the assessment of its resistance towards microbial attack. SEM images of treated fabric indicate copper nano particles are well dispersed on the surface of the specimens. The treatments of nano copper colloidal solution on cotton not only improve its antimicrobial efficiency but also influenced the tensile strength of the fabric sample positively. The treatment was found to enhance the color depth and fastness properties of direct dyed cotton fabric samples.

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