Indentation Tests for Sintered Silver in Die-Attach Interconnection After Thermal Cycling

2021 ◽  
Author(s):  
Fei Qin ◽  
Shuai Zhao ◽  
Yanwei Dai ◽  
Lingyun Liu ◽  
Tong An ◽  
...  
Keyword(s):  
Thermal Cycling ◽  
Young’S Modulus ◽  
Mechanical Performance ◽  
Young's Modulus ◽  
Silver Layer ◽  
Thermal Cycles ◽  
Nano Indentation ◽  
Die Attach ◽  
Indentation Tests ◽  
Sintered Silver

Abstract Thermo-mechanical reliability assessment for sintered silver is a crucial issue as sintered silver is a promising candidate of die-attachment materials for power devices. In this paper, the nano-indentation tests are performed for sintered silver in typical die-attach interconnection under different thermal cycles. Based on thermal cycling test, the Young's modulus and hardness of sintered silver layer have been presented. It is found that the Young's modulus and hardness of sintered silver layer changes slightly although the microstructure of sintered silver also presents some variations. The stress and strain curves for different thermal cycling tests for sintered silver based on reverse analysis of nano-indentation are also given. The results show that the elastoplastic constitutive equations change significantly after thermal cycling tests, and the yielding stress decreases remarkably after 70 thermal cycles. The experimental investigation also show that the cracking behaviors of sintered silver depends on its geometry characteristics, which implies that the possible optimization of sintered silver layer could enhance its thermo-mechanical performance.

Thermal Cycling Effect on Mechanical Properties, Grain Size and Residual Stress in Alumina and Yttria-Stabilized Tetragonal Zirconia

2014 ◽  
Vol 875-877 ◽  
pp. 1642-1646
Author(s):  
Jing Zhang
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Grain Size ◽  
Thermal Cycling ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Tetragonal Zirconia ◽  
Thermal Cycles ◽  
Optical Applications ◽  
Increasing Temperature

Alumina and zirconia are important materials for energy and optical applications. In this study, the effect of thermal cycling on grain size and residual stress was reported. Residual stress was measured using X-ray diffraction (XRD) sin2ψ method for the as-received and the samples after thermal cycling up to 900 cycles. For alumina, the measured residual stress is approximately 96 MPa in tensile for the as-received material, and increases to its highest value of 480 MPa after 650 thermal cycles. The residual stress decreases from 480 MPa to 96 MPa in tensile with increased thermal cycling from 650 to 900 cycles. The crystallized grain size calculated from the diffraction pattern shows that the mean crystallized grain size is about 93 nm for the as-received and increases to 232 nm after 650 thermal cycles. This result is consistent with the enlarged grain size observed by scanning electron microscopy for the alumina after 650 thermal cycles reported earlier. With continued thermal cycling up to 900 cycles, the crystallized grain size is greatly reduced to 104 nm. It suggests that evolution of the crystallized grain size is correlated with the residual stress. For yttria-stabilized tetragonal zirconia (Y-TZP), the mechanical properties at room temperature, are consistent with the property values provided by the manufacturer. The Young’s modulus of shows a non-linear inverse relationship with increasing temperature. The degradation of the Young’s modulus mostly occurs prior to 400 °C and to a less extent in the temperature range of 400 °C up to 850 °C. The Vickers hardness number for the as-received Y-TZP material decreases to a very small extent after 560 thermal cycles and increases approximately 2%, after 1200 thermal cycles. This is consistent with the trend of the Young’s modulus for thermal-cycled specimens.

Evaluation of Mechanical Properties of SOFC Components by Nano-Indentation Tests

2010 ◽  
Author(s):  
Hideaki Ito ◽  
Kazuhisa Sato ◽  
Atsushi Unemoto ◽  
Koji Amezawa ◽  
Tatsuya Kawada
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Crystal Orientation ◽  
Young's Modulus ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Indentation Method ◽  
Nano Indentation ◽  
Electron Backscattering Diffraction ◽  
Indentation Tests

The Young’s modulus and the hardness of single crystals and polycrystalline sintered compacts of yttria-stabilized zirconia (YSZ), (Y2O3)x(ZrO2)1−x (x = 0.08, 0.10) was investigated by using the nano-indentation method. Together with results obtained by the secondary electron microscope observation and the electron backscattering diffraction analysis, the effect of the crystal orientation on the mechanical properties was discussed. It was empirically demonstrated that the Young’s modulus of YSZ depends on the crystal orientation. The Young’s modulus of YSZ showed the highest value on the (001) surface while the lowest value on the (111) surface. However, the observed anisotropy of the Young’s modulus was rather small compared with predicted one from the single crystal elastic constants in literature. Compared with the Young’s modulus, the anisotropy of the hardness of YSZ was less significant.

Young’s modulus of peritubular and intertubular human dentin by nano-indentation tests

2011 ◽  
Vol 174 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Daniel Ziskind ◽  
Moran Hasday ◽  
Sidney R. Cohen ◽  
H. Daniel Wagner
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Nano Indentation ◽  
Human Dentin ◽  
Indentation Tests

Measurement of Young's Modulus and Poisson's Ratio of Thin Film by Combination of Bulge Test and Nano-Indentation

2008 ◽  
Vol 33-37 ◽  
pp. 969-974 ◽  
Author(s):  
Bong Bu Jung ◽  
Seong Hyun Ko ◽  
Hun Kee Lee ◽  
Hyun Chul Park
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Applied Pressure ◽  
Indentation Test ◽  
Poisson's Ratio ◽  
Bulge Test ◽  
Nano Indentation

This paper will discuss two different techniques to measure mechanical properties of thin film, bulge test and nano-indentation test. In the bulge test, uniform pressure applies to one side of thin film. Measurement of the membrane deflection as a function of the applied pressure allows one to determine the mechanical properties such as the elastic modulus and the residual stress. Nano-indentation measurements are accomplished by pushing the indenter tip into a sample and then withdrawing it, recording the force required as a function of position. . In this study, modified King’s model can be used to estimate the mechanical properties of the thin film in order to avoid the effect of substrates. Both techniques can be used to determine Young’s modulus or Poisson’s ratio, but in both cases knowledge of the other variables is needed. However, the mathematical relationship between the modulus and Poisson's ratio is different for the two experimental techniques. Hence, achieving agreement between the techniques means that the modulus and Poisson’s ratio and Young’s modulus of thin films can be determined with no a priori knowledge of either.

Elastic constants of inflated lobes of dog lungs

1976 ◽  
Vol 40 (4) ◽  
pp. 508-513 ◽  
Author(s):  
S. J. Lai-Fook ◽  
T. A. Wilson ◽  
R. E. Hyatt ◽  
J. R. Rodarte
Keyword(s):  
Bulk Modulus ◽  
Young’S Modulus ◽  
Elastic Constants ◽  
Young's Modulus ◽  
Poisson Ratio ◽  
Inflation Pressure ◽  
Initial State ◽  
Volume Curve ◽  
Pressure Volume Curve ◽  
Indentation Tests

The elastic constants of dog lungs were determined at various degrees of inflation. In one set of experiments, the lobes were subjected to deformations that approximated the conditions of uniaxial loading. These data, together with the bulk modulus data obtained from the local slope of the pressure-volume curve, were used to determine the two elastic moduli that are needed to describe small nonuniform deformations about an initial state of uniform inflation. The bulk modulus was approximately 4 times the inflation pressure, and Young's modulus was approximately 1.5 times the inflation pressure. In a second set of experiments, lobes were subjected to indentation tests using cylindric punches 1–3 cm in diameter. The value for Young's modulus obtained from these data was slightly higher, approximately twice the inflation pressure. These experiments indicate that the lung is much more easily deformable in shear than in dilatation and that the Poisson ratio for the lung is high, approximately 0.43.

Highly Flexible Die Attach Adhesives for MEMS packages

2012 ◽  
Vol 2012 (1) ◽  
pp. 001169-001177 ◽  
Author(s):  
Tobias Königer
Keyword(s):  
Mechanical Stress ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Assembly Process ◽  
Processing Times ◽  
Heat Curing ◽  
Die Attach ◽  
Negative Effect ◽  
Dual Curing ◽  
Flexible Die

Die attach materials for most MEMS packages must be highly flexible as temperature changes during the assembly process and application may lead to thermo-mechanical stress as a consequence of dissimilar coefficients of thermal expansion of substrate, chip and adhesive. Thermo-mechanical stress results in a distortion of the signal characteristics of the extremely stress-sensitive MEMS device. Within the scope of this paper, highly flexible heat-curing adhesives with a Young's modulus down to 5 MPa (0.725 ksi) at room temperature were developed. DMTA measurements show that temperature storage at +120 °C (+248 °F) does not cause the adhesive to embrittle, which would have a negative effect on the MEMS package's reliability. After storage at +120 °C (+248 °F) for up to 1000 h, no increase in Young's modulus can be observed. The adhesives cure at extremely low temperatures down to +100 °C (+212 °F), which reduces stress development during the assembly process. In addition, the adhesives have very process-friendly properties. Processing times of more than one week can be achieved. The option of dual curing enables preliminary light fixation of the chip within just seconds.

scholarly journals Kinetics of Capability Aging in Ti-13Nb-13Zr Alloy

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 693 ◽  
Author(s):  
Myoungjae Lee ◽  
In-Su Kim ◽  
Young Hoon Moon ◽  
Hyun Sik Yoon ◽  
Chan Hee Park ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Young’S Modulus ◽  
Mechanical Performance ◽  
Young's Modulus ◽  
Solution Treatment ◽  
High Strength ◽  
Biomedical Implant ◽  
13Zr Alloy ◽  
American Society ◽  
Kinetics Of

Metals for biomedical implant applications require a simultaneous achievement of high strength and low Young’s modulus from the viewpoints of mechanical properties. The American Society for Testing and Materials (ASTM) standards suggest two types of processing methods to confer such a mechanical performance to Ti-13Nb-13Zr alloy: solution treatment (ST) and capability aging (CA). This study elucidated the kinetics of CA process in Ti-13Nb-13Zr alloy. Microstructural evolution and mechanical change were investigated depending on the CA duration from 10 min to 6 h. The initial ST alloy possessed the full α′-martensitic structure, leading to a low strength, low Young’s modulus, and high ductility. Increasing CA duration increased mechanical strength and Young’s modulus in exchange for the reduction of ductility. Such a tendency is attributed to the decomposition of α′ martensite into (α+β) structure, particularly hard α precipitates. Mechanical compatibility (i.e., Young’s modulus compensated with a mechanical strength) of Ti-13Nb-13Zr alloy rarely increased by changing CA duration, suggestive of the intrinsic limit of static heat treatment.

Graphene oxide and zinc oxide decorated chitosan nanocomposite biofilms for packaging applications

2020 ◽  
Vol 40 (2) ◽  
pp. 152-157 ◽  
Author(s):  
Pınar Terzioglu ◽  
Yasin Altin ◽  
Ayse Kalemtas ◽  
Ayse Celik Bedeloglu
Keyword(s):  
Tensile Strength ◽  
Zinc Oxide ◽  
Graphene Oxide ◽  
Composite Film ◽  
Young’S Modulus ◽  
Mechanical Performance ◽  
Young's Modulus ◽  
Chitosan Film ◽  
Oxide Composite ◽  
Wide Range

AbstractRecently, due to sustainable development and environmental protection policies, there is increasing interest in the development of new biodegradable polymer-based multifunctional composites. Chitosan is one of the most remarkable and preferred biopolymers, which is environmentally friendly as well as renewable, biocompatible, and inexpensive. Though it has a wide range of potential applications, the major limitation of chitosan – the problem of poor mechanical performance – needs to be solved. In this work, graphene oxide was first produced and then used to manufacture a chitosan/graphene oxide/zinc oxide composite film through a casting method. The properties of the chitosan film and the chitosan/graphene oxide/zinc oxide composite film were investigated using Fourier transform infrared spectroscopy, mechanical, thermal gravimetric, and ultraviolet (UV)-visible spectroscopy analyses. The results showed that the incorporation of graphene oxide and zinc oxide into the chitosan matrix resulted in enhanced mechanical properties and thermal stability of chitosan biocomposite films. The graphene oxide- and zinc oxide-reinforced chitosan film showed 2527 MPa and 55.72 MPa of Young’s modulus and tensile strength, respectively, while neat chitosan showed only 1549 MPa and 37.91 MPa of Young’s modulus and tensile strength, respectively. Conversely, the addition of graphene oxide decreased the transmittance, notably in the UV region.

Evaluation of WB Coatings by Scanned Imaging Microscopy

2003 ◽  
Author(s):  
Jikai Du ◽  
Bernhard R. Tittmann
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Attenuation Coefficients ◽  
High Attenuation ◽  
Nano Indentation ◽  
Atomic Force ◽  
Acoustic Evaluation ◽  
Acoustic Velocities ◽  
Thick Coatings ◽  
Scanning Acoustic Microscope

Organic thick coatings (epoxy, polyurethane, and acrylic-urethane) have been widely applied to high modulus substrates (e.g., steel) for anticorrosion protection. To improve performance, reinforced components (clay, bochmite, nanopaticles, etc.) are usually added to these coatings. However, the acoustic evaluation of these coatings is difficult due to their low acoustic velocities and high attenuation coefficients. In this paper, first, the scanning acoustic microscope (SAM) is used to image sub-surfaces, coating/substrate interfaces, and to measure acoustic velocities. Different phases can be observed on some coatings and defects can be found at some interfaces. Secondly, the atomic force microscope (AFM) is applied to image surfaces at high resolution (compared to SAM). These results agree with SAM images. Thirdly, a nano-indentation technique is utilized to measure the reduced Young’s modulus and absolute hardness of the coatings. The results show that epoxy has the highest Young’s modulus and acrylic-urethane has the lowest. Reinforced components can either increase or decrease Young’s modulus, and hardness depending on the coating material. Finally, results from the SAM, AFM and nano-indentation are compared and analyzed to optimize the evaluation.

High Temperature Mechanical Properties of Ni-YSZ Cermets for SOFC Anode

2010 ◽  
Author(s):  
Fumitada Iguchi ◽  
Hiromichi Kitahara ◽  
Hiroo Yugami
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Flexural Strength ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Strain Diagram ◽  
Thermal Cycles ◽  
High Temperature Mechanical Properties ◽  
Sofc Anode ◽  
The Difference

The mechanical properties of Ni-YSZ cermets at high temperature in reduction atmosphere were evaluated by the four points bending method. We studied the influences of reduction and thermal cycles, i.e. a cycle from R.T. to 800°C, to flexural strength and Young’s modulus. The flexural strength of Ni-YSZ at room temperature was lower than that of NiO-YSZ by about 10 to 20% mainly caused by the increment of porosity. But, the flexural strength of Ni-YSZ at 800°C was drastically decreased by an half of that at R.T. In addition, the stress–strain diagram of Ni-YSZ at 800°C indicated that it showed weak ductility. The maximum observed strain was over 0.5% at 30MPa. On the contrary, NiO-YSZ showed only brittlely at 800°C. The difference was caused by Ni metal in the Ni-YSZ cermets. Therefore, it was expected that Ni-YSZ is easily deformed in operation, though residual stress between an anode and an electrolyte was low. The influence of thermal cycles to flexural strength and Young’s modulus was not observed clearly. At the same time, the differences of microstructure were not observed. Therefore, it was concluded that the cycle does not change mechanical properties significantly.

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