Effect of various parameters on the shear strength of solid-state nanoporous Cu bonding in Cu–Cu disks for power device packaging

2021 ◽  
Author(s):  
Byungho Park ◽  
Duy le Han ◽  
Mikkiko Saito ◽  
Jun Mizuno ◽  
Hiroshi Nishikawa
Keyword(s):  
Electron Microscopy ◽  
Shear Strength ◽  
Solid State ◽  
Formic Acid ◽  
Bonding Temperature ◽  
X Ray Diffraction ◽  
Promising Alternative ◽  
Transmission Electron ◽  
Cu Bonding ◽  
Bonding Method

Abstract Nanoparticle sintering is considered a promising alternative bonding method to Pb- based soldering for the attachment of components in high-temperature electronic devices. However, the technology still poses certain challenges, such as difficulty controlling joint thickness and the generation of voids owing to solvent evaporation. In this study, a solid-state (solvent-free), nanoporous-Cu (NPC) bonding method was examined. The effect of bonding temperatures (200–400°C) and atmospheres (N2 or formic acid) on the shear strength of joints formed between NPC sheets and bare Cu disks were investigated by scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. It was shown that the bondability of NPC under an N2 atmosphere is closely related to the oxide layer formed on its surface that impairs the diffusion of Cu atoms between the NPC and Cu substrate. Furthermore, the coarsening of the NPC microstructure under a formic acid atmosphere at ≥ 350°C owing to the rapid diffusion of Cu atoms and accompanying plastic deformation induced by surface stress enhances the shear strength of the resulting NPC/Cu joint. The shear strength of NPC/Cu joints formed under a formic acid atmosphere increased from 14.1 to 35.9 MPa with increasing bonding temperature. Based on the results of the investigation, a mechanism was proposed to explain the superiority of the Cu–Cu joints achieved using this method.

Preparation of PVC/Kaolin Nanocomposites through Solid State Shear Compounding Based on Pan-Milling

2011 ◽  
Vol 694 ◽  
pp. 350-354 ◽  
Author(s):  
Kan She Li ◽  
Ying Hong Chen ◽  
Hong Mei Niu ◽  
Jian Jun Chen
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
Solid State ◽  
Impact Strength ◽  
Ambient Temperature ◽  
Mechanical Tests ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Filled Composite

Solid state shear compounding technology (S3C) based on pan-milling is an effective method to prepare polymer/layered mineral composites with nano intercalating structure. The PVC/Kaolin compounding powders were successfully prepared by pan-milling at ambient temperature, and then the PVC/Kaolin nanocomposites were processed by moulding The structure and properties of PVC/Kaolin compounding powder and nanocomposites were investigated by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and mechanical tests. The results showed that the mechanical properties of PVC/Kaolin nanocomposites prepared through S3C based on pan-milling 30 cycles at ambient temperature including elongation, tensile strength and notched impact strength were remarkably improved compared with conventional filled composites. The elongation of PVC / Kaolin nanocomposites with 4 %wt. Kaolin was 274.6%, which is 187.3 % higher than that for a conventional filled composite. The tensile strength was 54.0 MPa, which is 6.3 MPa higher than that for a conventional filled composite. The tensile strength of the nanocomposites with 8 %wt. Kaolin was 57.5 MPa, which is 9.1 MPa higher than that for a conventional filled composite. At the same time, the notched impact strength was 4.9 kJ/m2, which is 1.0 kJ/m2 higher than a conventional filled composite. Strengthening and toughening for PVC were synchronously realized. XRD, SEM and TEM verified that S3C based on pan-milling realized synchronously pulverizing, dispersion and compounding of PVC with kaolin Through 25-30 cycles pan-milling, PVC and Kaolin powders imbedded each other and made into uniform PVC/Kaolin compounding powders and nanocomposites. The strip flake of Kaolin particles with thickness less than 50 nanometer and the aspect ratio of 10 times dispersed homogeneously in the PVC matrix.

SOLID STATE AMORPHIZATION IN MECHANICALLY ALLOYED Al–Ti–Si NANOCOMPOSITES

2005 ◽  
Vol 04 (05n06) ◽  
pp. 1025-1028
Author(s):  
I. MANNA ◽  
P. NANDI ◽  
B. BANDYOPADHYAY ◽  
P. M. G. NAMBISSAN ◽  
K. GHOSHRAY ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Amorphous Solid ◽  
Positron Annihilation Spectroscopy ◽  
Intermetallic Phases ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
X Ray ◽  
Transmission Electron ◽  
State Amorphization

The microstructural evolution at different stages of milling of a ternary powder blend of Al 50 Ti 40 Si 10 composition was monitored by X-ray diffraction, high-resolution transmission electron microscopy, positron annihilation spectroscopy and 27 Al nuclear magnetic resonance. Ball-milling leads to alloying, nanocrystallization and partial solid state amorphization, either followed or accompanied by strain-induced nucleation of nanocrystalline intermetallic phases from an amorphous solid solution.

A Study of Solid State Bonding Strength of Nonferrous Metals by Using Metal Salt Generation Bonding Method

2014 ◽  
Vol 783-786 ◽  
pp. 2450-2455
Author(s):  
Shinji Koyama
Keyword(s):  
Solid State ◽  
Formic Acid ◽  
Metal Salt ◽  
Bonding Temperature ◽  
Copper Surface ◽  
Solid State Bonding ◽  
Bonded Joint ◽  
Set Up ◽  
Bonding Method ◽  
Aluminum Surfaces

In recent years, an enormous pressure was put on the need to design and develop products that are compliant with the stringent environmental regulations set up various countries. Among the problems that need to be addressed is the need to design and develop environmentally friendly products that are energy efficient and easy to recycle. In this study, the effect of metal salt generation processing on the tensile strength of the bonded interface of Al/Al and Al/Cu was investigated by SEM observations of interfacial microstructures and fractured surfaces. Aluminum surfaces were modified by boiling in 5% aqueous solution of NaOH for 30 s and 98% formic acid for 60 s. Copper surface were modified by boiling 98% formic acid for 60 s. Solid-state bonding was performed at bonding temperature of 673 ~ 813 K and under a pressure of 6 MPa ( bonding time of 1.8 ks). Using metal salt generation bonding technique, the bonded joint is able to reach 0.2% proof stress at lower bonding temperature and with less deformation.

Solid-state reaction of Ru powder in molten AlxBi1−x

1990 ◽  
Vol 5 (4) ◽  
pp. 746-753 ◽  
Author(s):  
R. W. Johnson ◽  
C. M. Garland
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Alloy System ◽  
Reaction Cross ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Metal Solvent

We describe a low-temperature solid-state interdiffusion technique that allows reaction between spatially separated reacting species and its application in the Al–Ru alloy system. This technique uses a liquid-metal solvent (Bi) as a medium for the transfer of Al to the surface of Ru powder where reaction occurs with the formation of nanocrystalline AlxRu1−x product phases. X-ray diffraction measurements are used to follow the time and temperature dependence of the reaction. Cross-sectional transmission electron microscopy allows direct imaging of the growth and morphology of the AlxRu1−x product phases.

A solid-state approach for the low temperature synthesis of Cr3Si hollow particles

2021 ◽  
Vol 112 (11) ◽  
pp. 918-921
Author(s):  
Liangbiao Wang ◽  
Zhe Chen ◽  
Yongjie Xie ◽  
Yuting Xiong ◽  
Qinglin Cheng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Silicon Powder ◽  
Diffraction Field ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Low Temperature Synthesis ◽  
Hollow Particles ◽  
Transmission Electron ◽  
Metallic Lithium

Abstract In this paper, pure cubic chromium silicide (Cr3Si) hollow particles have been successfully synthesized through the solid-state reaction of chromium sesquioxide, silicon powder and metallic lithium in an autoclave at 600 °C for 10 h. The as-prepared samples were characterized by means of X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy, which showed that the as-prepared samples were cubic phase Cr3Si hollow particles. Furthermore, the oxidation resistance of the obtained Cr3Si sample was also investigated.

Distinctive characteristics of solid-state reactions in mechanically alloyed Ti–Al–Si–C powder mixtures

2005 ◽  
Vol 20 (2) ◽  
pp. 375-385 ◽  
Author(s):  
J.B. Zhou ◽  
K.P. Rao
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Powder Mixture ◽  
Energy Dispersive Spectrometry ◽  
Solid State Reactions ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Powder Mixtures ◽  
Transmission Electron ◽  
Submicron Scale

Ti–Al–Si–C powder mixtures of two different compositions, namely, 58Ti–30Al–6Si–6C (at.%) and 50Ti–15Al–20Si–15C (at.%), were mechanically alloyed to investigate the solid-state reactions during such a process. The mechanically alloyed powders were characterized as a function of milling time by x-ray diffraction (XRD), scanning electron microscopy, energy-dispersive spectrometry, and transmission electron microscopy (TEM). XRD results showed that solid solutions of Ti were formed for a powder mixture of 58Ti–30Al–6Si–6C in about 20 h of milling, whereas Ti5(Al,Si)3 and Ti(Al,Si)C compounds started to form in the powder mixture of 50Ti–15Al–20Si–15C within just 5 h of milling. TEM observations demonstrated that the particle sizes were of nano and submicron scale in both cases. This investigation indicated that in mechanically alloyed Ti–Al–Si–C powder mixtures, the main solid-state reactions are due to interdiffusion and mechanically induced self-propagating reaction.

scholarly journals A Study and Comparison of the Preparation of Gadolinium Aluminate Nanoparticles Using γ-Irradiated and Unirradiated Precursors

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Tehani I. Al-Muhimeed ◽  
Abdullah A. Al-Kahtani ◽  
Refaat M. Mahfouz ◽  
Mujeeb Khan ◽  
M. Rafiq H. Siddiqui
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Sol Gel ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Sintered Pellet ◽  
X Ray Diffraction ◽  
Gadolinium Nitrate ◽  
Transmission Electron ◽  
Sol Gel Process

The effects of γ-irradiation and the application of different precursors on the formation of gadolinium aluminate (GdAlO3) nanoparticles (NPs) have been studied in detail. GdAlO3 NPs were prepared by using different gadolinium-based precursors including gadolinium acetate (Gd(CH3COO)3·4H2O) and gadolinium nitrate (Gd(NO3)3·6H2O), while Al2O3 and Al(NO3)3·9H2O were used as the source of Al3+. The preparation of GdAlO3 was carried out by two different methods, solid-state reaction and sol-gel process. To study the effect of γ-irradiation, both irradiated and unirradiated Gd(CH3COO)3·4H2O have been tested for the preparation of gadolinium aluminate (GdAlO3). Notably, Gd(CH3COO)3·4H2O did not produce GdAlO3 in both solid-state and sol-gel processes even after optimizing various parameters, including the application of γ-irradiation. However, single-phase nanocrystalline GdAlO3 NPs were successfully obtained from the reaction of gadolinium nitrate Gd(NO3)3·6H2O and Al(NO3)3·9H2O by a sol-gel process. The formation of NPs has been confirmed by X-ray diffraction analysis (XRD) and Fourier-transform infrared (FT-IR) spectroscopy. The results indicate towards the formation of an orthorhombic perovskite structure of GdAO3 in the Pbnm space group. Transmission electron microscopy (TEM) has been employed for the particle-size analysis, which revealed the formation of spherical-shaped nanoparticles with the size range of 50–70 nm. Surface morphology of the sintered pellet was obtained from high-resolution scanning electron microscopy (HR-SEM). Besides, the effect of irradiation with γ-rays on the quality of resultant NPs has also been studied.

EM observation on poly(β-alanine) crystal formed by the thermal solid State polymerization

1990 ◽  
Vol 48 (4) ◽  
pp. 858-859
Author(s):  
Hirokazu Kimura ◽  
Hiroshi Sakabe ◽  
Hitoshi Morita ◽  
Takashi Itoh ◽  
Takashi Konishi
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Single Crystal ◽  
Single Crystals ◽  
Water Solution ◽  
Aminocaproic Acid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Solid State Polymerization

It is well known that several ω-amino acids are polymerized in the solid state. A single crystal of ε-aminocaproic acid has been reported to be polymerized in the solid state to be the biaxially oriented nylon 6. We also reported in the previous paper that the thermal solid state polymerization of glycine single crystal produced poly(glycine-I) crystal.In this paper,structure of poly(β-alanine) polymerized in the solid state is investigated by means of scanning electron microscopy (SEM).transmission electron microscopy (TEM) and X-ray diffraction.Commercial β-alanine (Nakarai Tesque,Inc.,Kyoto) was recrystallized three times from the distilled-water solution (lg/ml) at 80°C. The single crystal continued to grow gradually during 24 hr. The obtained single crystals with rhombic habit had clear cleavage planes. These single crystals about 10 mm in size were used as the original specimens. The polymerization procedure was carried out on the single crystals at temperatures between 140 and 170°C in an evacuated and subsequently sealed tube.

Solid State Synthesis and Characterization of NiTe Nanocrystals

2014 ◽  
Vol 29 ◽  
pp. 35-39 ◽  
Author(s):  
C.E.M. Campos
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Processing Time ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Selected Area Electron Diffraction ◽  
Nickel Powders ◽  
Transmission Electron ◽  
Average Size

NiTe nanocrystals were prepared through facile and fast solid state reaction (mechanical alloying) of pure elemental tellurium and nickel powders in an argon atmosphere. The samples processed for 3 h, 5 h and 10 h were characterized by X-ray diffraction, transmission electron microscopy, magnetization and Raman spectroscopy. Hexagonal NiTe crystals with an average size of 30 nm can be obtained after only 3 h of processing time. Transmission electron microscopy images showed a broad crystalline size distribution in the agglomerated particles and selected area electron diffraction revealed its crystalline character. NiTe ferromagnetic behavior was confirmed and magnetic parameters were dependent on processing time. Raman spectra showed no unreacted Te or tellurium oxides, but it also showed that laser induced phases transitions (including Te re-crystallization) can be observed for modest laser power (<3 mW).

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