scholarly journals Effect of Sintering Conditions on the Mechanical Strength of Cu-Sintered Joints for High-Power Applications

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2105 ◽  
Author(s):  
Jeong-Won Yoon ◽  
Jong-Hoon Back
Keyword(s):  
Shear Strength ◽  
Low Cost ◽  
Sintering Process ◽  
Bonding Pressure ◽  
Sintering Time ◽  
Sinter Bonding ◽  
Sintering Conditions ◽  
Metallic Bonding ◽  
Mechanical Strengths ◽  
Direct Bond Copper

In this study, the feasibility of low-cost Cu-sintering technology for power electronics packaging and the effect of sintering conditions on the bonding strength of the Cu-sintered joint have been evaluated. A Cu paste with nano-sized Cu powders and a metal content of ~78% as a high-temperature bonding material was fabricated. The sinter-bonding reactions and mechanical strengths of Cu-sintered joints were evaluated at different sinter bonding pressures, temperatures, and durations during the sintering process. The shear strength of the Cu-sintered joints increased with increasing sintering pressure. Good interfacial uniformity and stable metallurgical microstructures were observed in the Cu joints sintered at a high sintering pressure of 10 MPa, irrespective of the sintering time. It was confirmed that a high-pressure-assisted sintering process could create relatively dense sintered layers and good interfacial uniformity in the Cu-sintered joints, regardless of the sintering temperatures being in the range of 225–300 °C. The influence of the sinter bonding pressure on the shear strengths of the Cu-sintered joints was more significant compared to that of the sintering temperature. Durations of 10 min (at 300 °C) and 60 min (at 225 and 250 °C) are sufficient for complete sintering reactions between the Si chip and the direct bond copper (DBC) substrate. Relatively good metallic bonding and dense sintered microstructures created by a high sintering pressure of 10 MPa resulted in high shear strength in excess of 40 MPa of the Cu-sintered joints.

Preparation and Properties of PTFE/SA Blend Membrane

2011 ◽  
Vol 332-334 ◽  
pp. 939-944 ◽  
Author(s):  
Liang Li ◽  
Chang Fa Xiao ◽  
Qing Lin Huang ◽  
Xiao Yu Hu
Keyword(s):  
Thermal Stability ◽  
Sintering Process ◽  
Hydrophobic Property ◽  
Excellent Thermal Stability ◽  
Sintering Time ◽  
Before And After ◽  
Sintering Conditions ◽  
Surface Morphologies ◽  
Flat Membranes ◽  
Concentrated Dispersion

Poly (tetrafluoroethylene) (PTFE)/Salt alginate (SA) flat membranes were prepared from a mixture of PTFE concentrated dispersion and Sodium alginate (NaAlg) aqueous solution. The chemical constitutions of the PTFE/SA membranes before and after sintering were investigated with FTIR. Meanwhile, TGA and contact angle to water were utilized to analyze the thermal stability and hydrophobic property. Moreover, effects of sintering conditions on the properties and morphologies of the membranes were also investigated. Results showed that SA was decomposed in the sintering process, and the membranes maintained excellent thermal stability and strong hydrophobicity. In addition, it was beneficial for the membranes to obtain high air flux by short sintering time and the membranes had different surface morphologies by different cooling rates.

scholarly journals Microwave Sintering and Microwave Dielectric Properties of (1–x)Ca0.61La0.26TiO3-xNd(Mg0.5Ti0.5)O3 Ceramics

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 438
Author(s):  
Shuwei Yang ◽  
Bingliang Liang ◽  
Changhong Liu ◽  
Jin Liu ◽  
Caisheng Fang ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Mobile Communications ◽  
Sintering Temperature ◽  
Microwave Sintering ◽  
Microwave Dielectric Properties ◽  
Conventional Heating ◽  
Sintering Process ◽  
Microwave Dielectric ◽  
Sintering Time ◽  
Frequency Temperature

The (1–x)Ca0.61La0.26TiO3-xNd(Mg0.5Ti0.5)O3 [(1–x)CLT-xNMT, x = 0.35~0.60] ceramics were prepared via microwave sintering. The effects of sintering temperature and composition on the phase formation, microstructure, and microwave dielectric properties were investigated. The results show that the microwave sintering process requires a lower sintering temperature and shorter sintering time of (1–x)CLT-xNMT ceramics than conventional heating methods. All of the (1–x)CLT-xNMT ceramics possess a single perovskite structure. With the increase of x, the dielectric constant (ε) shows a downward trend; the quality factor (Qf) drops first and then rises significantly; the resonance frequency temperature coefficient (τf) keeps decreasing. With excellent microwave dielectric properties (ε = 51.3, Qf = 13,852 GHz, τf = −1.9 × 10−6/°C), the 0.65CLT-0.35NMT ceramic can be applied to the field of mobile communications.

Preparation and application of water-based nano-silver conductive ink in paper-based 3D printing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chenfei Zhao ◽  
Jun Wang ◽  
Lini Lu
Keyword(s):  
Flexible Electronics ◽  
Low Cost ◽  
Methyl Cellulose ◽  
Conductive Ink ◽  
Content Type ◽  
Nano Silver ◽  
Printed Circuit ◽  
Silver Ink ◽  
Sintering Time ◽  
Water Based

Purpose In flexible electronics applications, organic inks are mostly used for inkjet printing. Three-dimensional (3 D) printing technology has the advantages of low cost, high speed and good precision in modern electronic printing. The purpose of this study is to solve the high cost of traditional printing and the pollution emissions of organic ink. It is necessary to develop a water-based conductive ink that is easily degradable and can be 3 D printed. A nano-silver ink printed circuit pattern with high precision, high conductivity and good mechanical properties is a promising strategy. Design/methodology/approach The researched nano-silver conductive ink is mainly composed of silver nanoparticles and resin. The effect of adding methyl cellulose on the ink was also explored. A simple 3 D circuit pattern was printed on photographic paper. The line width, line length, line thickness and conductivity of the printed circuit were tested. The influence of sintering temperature and sintering time on pattern resistivity was studied. The relationship between circuit pattern bending performance and electrical conductivity is analyzed. Findings The experimental results show that the ink has the characteristics of low silver content and good environmental protection effect. The printing feasibility of 3 D printing circuit patterns on paper substrates was confirmed. The best printing temperature is 160°C–180°C, and the best sintering time is 30 min. The circuit pattern can be folded 120°, and the cycle is folded more than 60 times. The minimum resistivity of the circuit pattern is 6.07 µΩ·cm. Methyl cellulose can control the viscosity of the ink. The mechanical properties of the pattern have been improved. The printing method of 3 D printing can significantly reduce the sintering time and temperature of the conductive ink. These findings may provide innovation for the flexible electronics industry and pave the way for alternatives to cost-effective solutions. Originality/value In this study, direct ink writing technology was used to print circuit patterns on paper substrates. This process is simple and convenient and can control the thickness of the ink layer. The ink material is nonpolluting to the environment. Nano-silver ink has suitable viscosity and pH value. It can meet the requirements of pneumatic 3 D printers. The method has the characteristics of simple process, fast forming, low cost and high environmental friendliness.

scholarly journals Controlled Assembly of Nanorod TiO2 Crystals via a Sintering Process: Photoanode Properties in Dye-Sensitized Solar Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Saeid Vafaei ◽  
Kazuhiro Manseki ◽  
Soki Horita ◽  
Masaki Matsui ◽  
Takashi Sugiura
Keyword(s):  
Solar Cells ◽  
Low Cost ◽  
Semiconductor Nanocrystals ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Sintering Process ◽  
Dye Sensitized ◽  
First Time ◽  
Sensitized Solar Cells ◽  
Control Crystallization

We present for the first time a synthetic method of obtaining 1D TiO2 nanorods with sintering methods using bundle-shaped 3D rutile TiO2 particles (3D BR-TiO2) with the dimensions of around 100 nm. The purpose of this research is (i) to control crystallization of the mixture of two kinds of TiO2 semiconductor nanocrystals, that is, 3D BR-TiO2 and spherical anatase TiO2 (SA-TiO2) on FTO substrate via sintering process and (ii) to establish a new method to create photoanodes in dye-sensitized solar cells (DSSCs). In addition, we focus on the preparation of low-cost and environmentally friendly titania electrode by adopting the “water-based” nanofluids. Our results provide useful guidance on how to improve the photovoltaic performance by reshaping the numerous 3D TiO2 particles to 1D TiO2-based electrodes with sintering technique.

scholarly journals Processing of porcelain stoneware tile using sugarcane bagasse ash waste

2015 ◽  
Vol 9 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Myrian Schettino ◽  
José Holanda
Keyword(s):  
Sugarcane Bagasse ◽  
Low Cost ◽  
Linear Shrinkage ◽  
Raw Material ◽  
Partial Replacement ◽  
Firing Cycle ◽  
Sintering Process ◽  
Natural Quartz ◽  
Sugarcane Bagasse Ash ◽  
Fast Firing

Large amounts of waste materials are discarded in the sugarcane industry. This work investigates the reuse of sugarcane bagasse ash waste as an alternative raw material for porcelain stoneware tile bodies, replacing natural quartz by up to 5 wt.%. The tile pieces were fired at 1230 ?C using a fast-firing cycle (< 60min). The technological properties of the fired tile pieces (e.g., linear shrinkage, water absorption, apparent density, and flexural strength) were determined. The sintering process was followed by SEM and XRD analyses. The results show that up to 2.5 wt.% sugarcane bagasse ash waste can be used as a partial replacement for quartz in porcelain stoneware tile (group BIa, ISO 13006 standard), providing excellent technical properties. Hence, its application in high-quality ceramic tile for use in civil construction as a low-cost, alternative raw material could be an ideal means of managing sugarcane bagasse ash waste.

scholarly journals Influence of prolonged sintering time on density and electrical properties of isothermally sintered cordierite-based ceramics

2013 ◽  
Vol 45 (2) ◽  
pp. 157-164 ◽  
Author(s):  
A. Peles ◽  
N. Djordjevic ◽  
N. Obradovic ◽  
N. Tadic ◽  
V.B. Pavlovic
Keyword(s):  
Electrical Properties ◽  
Mechanical Activation ◽  
Compaction Pressure ◽  
High Energy ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Air Atmosphere ◽  
Atomic Force ◽  
Sintering Time ◽  
High Energy Ball Mill

Mechanical activation is a commonly used and relatively fast and inexpensive procedure for sample preparation before the sintering process. Cordierite, a stoichiometric mixture of three different oxides (2MgO?2Al2O3?5SiO2) is a very attractive, widely used high-temperature ceramic material. The mechanical activation of the starting mixtures with 5.00 mass% TiO2 was performed in a high energy ball mill during 10-80 min. The applied compaction pressure before the sintering process was 2t/cm2, based on our recent investigation. The sintering process was performed at 1350oC for 2h and 4h in air atmosphere. X-ray diffraction was used to analyze the phase composition of non-activated and 80 min activated samples, sintered for 2 and 4h, respectively. Scanning electron microscopy was performed to analyze the microstructure of both compacted and sintered samples. Atomic force microscope was used to investigate the surface of the sintered samples. This paper investigates the influence of prolonged sintering time on the densities of the sintered samples, along with electrical properties.

Effects of Sintering Process on the Properties of Ti3SiC2/Cu Composite

2012 ◽  
Vol 512-515 ◽  
pp. 377-381 ◽  
Author(s):  
Jin Rong Lu ◽  
Yang Zhou ◽  
Yong Zheng ◽  
Shi Bo Li ◽  
Zhen Ying Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Sintering Temperature ◽  
Sintering Process ◽  
Vacuum Sintering ◽  
New Type ◽  
Sintering Conditions ◽  
The Relationship ◽  
Better Than

In this paper, a new type of Ti3SiC2/Cu composites with the volume fractions of 30% Ti3SiC2 particle was prepared by hot pressing and vacuum sintering respectively. The effects of sintering temperature and holding time on the density, resistance and Vickers hardness of Cu-30vol%Ti3SiC2 composite were investigated. The results show that the mechanical properties of the composites prepared by hot pressing are better than that prepared by vacuum sintering. The relative densities of Cu-30vol% Ti3SiC2 composites are rather high in suitable sintering conditions. It achieved 100% for the composites prepared by hot pressing at 930°C for 2h, and 98.4% for the composites prepared by vacuum sintering at 1250°C for 1h. At the same time, the maximum Vickers hardness reached 1735MPa at 900°C by hot pressing. The resistance and Vickers hardness of the composites decreased with an increase in sintering temperature, whereas the density increased. Scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS) were used to observe the microstructure of the composites. The relationship between microstructure and mechanical properties was discussed.

Control System of Sintering Furnace Based on Lonworks Net

2011 ◽  
Vol 48-49 ◽  
pp. 331-334
Author(s):  
Cheng Long Gong ◽  
Jing Zhuo Wang ◽  
Yuan Feng
Keyword(s):  
Control Strategy ◽  
Pid Control ◽  
Sintering Temperature ◽  
Computer Control ◽  
Network System ◽  
Sintering Process ◽  
Fuzzy Pid Control ◽  
Sintering Time ◽  
Combined Control ◽  
Cooling Speed

This paper introduces a computer control network system which can control sintering process of four PTFE molding furnaces accurately. System in-out signals such as sintering temperature, on-off signals of dial motor and aeration motor were connected to Lonworks via net nodes, and network variables were used to construct a configuration and interlinkage between the net nodes. We chose a combined-control strategy in which On-off control or Fuzzy-control or Fuzzy-PID control strategy were selected automatically, so the needs to sintering time, cooling speed, steady-state precision etc were accurately achieved.

A multi-pronged approach to low-pressure Cu sintering using surface-modified particles, substrate and chip metallization

2019 ◽  
Vol 2019 (1) ◽  
pp. 000387-000392 ◽  
Author(s):  
Sri Krishna Bhogaraju ◽  
Omid Mokhtari ◽  
Jacopo Pascucci ◽  
Fosca Conti ◽  
Hiren R Kotadia ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Cost ◽  
Surface Modifications ◽  
Low Pressure ◽  
Bonding Pressure ◽  
High Tendency ◽  
Promising Alternative ◽  
Die Attach ◽  
Bandgap Semiconductors ◽  
Surface Modified

Abstract High temperature power electronics based on wide-bandgap semiconductors have prominent applications, such as automotive, aircrafts, space exploration, oil/gas extraction, electricity distribution. Die-attach bonding process is an essential process in the realization of high temperature power devices. Here Cu offers to be a promising alternative to Ag, especially because of thermal and mechanical properties on par with Ag and a cost advantage by being a factor 100 cheaper than Ag. With the aim to achieve a low-pressure Cu sintering process, a low cost wet chemical etching process is developed to selectively etch Zn from brass to create nano-porous surface modifications to enhance sinterability, enabling sintering with low bonding pressure of 1MPa and at temperatures below 300°C. However, high tendency of Cu to oxidize poses a major challenge in realizing stable interconnects. For this purpose, in this contribution, we present the use of polyethylene-glycol 600 as reducing binder in the formulation of the Cu sintering paste. Finally, we propose a multi-pronged approach based on three crucial factors: surface-modified substrates, nanostructured surface modifications on micro-scale Cu-alloy particles and use of a reducing binder in the Cu particle paste.

PRESSURELESS SINTERING OF NANO- AG PASTE WITH LOW POROSITY FOR DIE ATTACH

2014 ◽  
Vol 2014 (1) ◽  
pp. 000092-000098 ◽  
Author(s):  
Sihai Chen ◽  
Guangyu Fan ◽  
Xue Yan ◽  
Chris LaBarbera ◽  
Lee Kresge ◽  
...  
Keyword(s):  
Shear Strength ◽  
Thermal Aging ◽  
Migration Rate ◽  
Dense Layer ◽  
Pressureless Sintering ◽  
Thermal Shock Test ◽  
Sintering Process ◽  
Shock Test ◽  
Die Attach ◽  
Ag Paste

A novel nano-Ag sintering paste C has been developed for a pressureless sintering process under air. Paste C was sintered at 250°C (C1) and 280°C (C2), respectively; C1 showed a slightly higher porosity but higher shear strength after aging at 250°C for 840 hours. Both C1 and C2 exhibited a microstructure much more stable than the control solder 92.5Pb/5Sn/2.5Ag, which suffered both IMC spalling after thermal aging and voiding. Ag migration toward the DBC to form a dense layer of AgCuNi(Au) was observed for all nano-Ag pastes that were studied, with C1 and C2 being more moderate in the migration rate. The Ag migration could be attributed to the tendency of Ag to form an alloy with Au, with abundant Ni and Cu at the DBC side, and appeared to be affected by the chemistry of nano-Ag paste. A liquid to liquid thermal shock test from −45°C to 240°C was attempted, and was considered too harsh for the die/DBC system employed in this study.

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