Fatigue and Creep Properties of Sintered Ag Paste from Room Temperature to High Temperature

Abstract This work introduces the possibility of using Ag sinter-paste as a novel high-temperature and high-current wire bonding solution. We investigated the electromigration (EM) behavior and lifetime of the sintered Ag wiring under high current density and high temperature required for the design of power electronic devices. The sinter Ag wiring fabricated on the two Cu substrates were tested under current densities of 2.7 × 104 A/cm2 at temperature of 250 °C. The microstructure evolution of sintered wiring was characterized after EM test. The resistance of sintered wiring did not change even after EM test for 300 hours, which confirms that the Ag-paste sinter wire bonding is rather stable than aluminum wire bonding under high temperature and high current density. No degradation was observed in microstructure of sintered wiring after EM test. Thus, it is expected that Ag paste sinter wire bonding is one of potential alternative interconnection technology for power electronic devices.

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Heat-Resistant Microporous Ag Die-Attach Structure for Wide Band-Gap Power Semiconductors

Materials ◽

10.3390/ma11122531 ◽

2018 ◽

Vol 11 (12) ◽

pp. 2531 ◽

Cited By ~ 2

Author(s):

Seungjun Noh ◽

Hao Zhang ◽

Katsuaki Suganuma

Keyword(s):

High Temperature ◽

Oxide Layer ◽

Morphological Evolution ◽

Void Formation ◽

Wide Band ◽

Thermal Reliability ◽

Power Semiconductors ◽

Die Attach ◽

Ag Paste ◽

Sintered Ag

In this work, efforts were made to prepare a thermostable die-attach structure which includes stable sintered microporous Ag and multi-layer surface metallization. Silicon carbide particles (SiCp) were added into the Ag sinter joining paste to improve the high-temperature reliability of the sintered Ag joints. The use of SiCp in the bonding structures prevented the morphological evolution of the microporous structure and maintained a stable structure after high temperature storage (HTS) tests, which reduces the risk of void formation and metallization dewetting. In addition to the Ag paste, on the side of direct bonded copper (DBC) substrates, the thermal reliability of various surface metallizations such as Ni, Ti, and Pt were also evaluated by cross-section morphology and on-resistance tests. The results indicated that Ti and Pt diffusion barrier layers played a key role in preventing interfacial degradations between sintered Ag and Cu at high temperatures. At the same time, a Ni barrier layer showed a relatively weak barrier effect due to the generation of a thin Ni oxide layer at the interface with a Ag plating layer. The changes of on-resistance indicated that Pt metallization has relatively better electrical properties compared to that of Ti and Ni. Ag metallization, which lacks barrier capability, showed severe growth in an oxide layer between Ag and Cu, however, the on-resistance showed fewer changes.

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Microstructural evolution and Mechanical Properties of a Newly Developed Ti2AlNb-based alloy

MATEC Web of Conferences ◽

10.1051/matecconf/202032111064 ◽

2020 ◽

Vol 321 ◽

pp. 11064

Author(s):

Yongsheng HE ◽

Wenzhong LUO ◽

Yujun DU ◽

Ming WU ◽

Kaixuan Wang ◽

...

Keyword(s):

Tensile Strength ◽

High Temperature ◽

Room Temperature ◽

Phase Region ◽

High Plasticity ◽

Phase Zone ◽

Creep Properties ◽

Three Phase ◽

High Temperature Tensile ◽

High Temperature Tensile Properties

The effects of the microstructure on the tensile and creep properties of the alloy at room temperature and high temperature were investigated by controlling the microstructures of the alloy by different hot working processes. It is found that the lath microstructure obtained by forging in B2 single phase zone has high tensile strength. The tensile strength is 1188 MPa at room temperature and 950 MPa at high temperature. The equiaxed structure obtained by forging in O+B2 phase region has the characteristics of high plasticity, creep resistance and low tensile strength. The elongation at room temperature is 9.0%, and the elongation at high temperature is 36%. The ambient temperature, high temperature tensile properties of the dual microstructure obtained by forging in the three-phase zone of α2+O+B2 are between the lath and the equiaxed microstructure.

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Creep Behavior of Near α High Temperature Ti-6.6Al-4.6Sn-4.6Zr-0.9Nb-1.0Mo-0.32Si Alloy

Frontiers in Materials ◽

10.3389/fmats.2021.682831 ◽

2021 ◽

Vol 8 ◽

Author(s):

Dongye Yang ◽

Wenqi Tian ◽

Xinqi Zhang ◽

Ke Si ◽

Jiuxiao Li

Keyword(s):

High Temperature ◽

Room Temperature ◽

Creep Mechanism ◽

Creep Properties ◽

Microstructure Characteristics ◽

Transmission Electron ◽

Diffusion Controlled ◽

Dislocation Movement ◽

Alloy Microstructure ◽

Applied Stresses

This study focuses on the microstructure characteristics and tensile and creep properties of a near α high temperature Ti-6.6Al-4.6Sn-4.6Zr-0.9Nb-1.0Mo-0.32Si alloy. Microstructure characteristics were quantitatively investigated using optical microscopy, scanning electron microscope, and transmission electron microscopy. Tensile properties were carried out at room and high temperature. Creep properties were detected under applied stresses ranging from 100–350 MPa at 873–973 K, respectively. Results showed that Widmanstätten microstructure was obtained after hot forged and heat treatment. The strength decreases and the elongation rises with temperature increasing. The ultimate strength and elongation were 1010 MPa, 12% at room temperature, and 620 MPa, 20% at 923 K, respectively. The steady state creep rates rise correspondingly with stress and temperature. Stress exponents are measured within the range of 3.0–3.5. Thus, the creep mechanism is diffusion-controlled viscous glide of dislocation. Ti3Al precipitates are observed. The boundaries and precipitates can obstruct dislocation movement to improve the creep properties. Fracture mechanism of creep is intergranular. The creep mechanism varied from climb of dislocation to sliding of dislocation solution.

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ABOUT HEAT CAPACITY OF TITANIUM CARBIDE TiCx

Alternative Energy and Ecology (ISJAEE) ◽

10.15518/isjaee.2019.01-03.056-066 ◽

2019 ◽

pp. 56-66

Author(s):

I. Khidirov ◽

V. V. Getmanskiy ◽

A. S. Parpiev ◽

Sh. A. Makhmudov

Keyword(s):

Heat Capacity ◽

High Temperature ◽

Titanium Carbide ◽

Temperature Dependence ◽

Carbon Concentration ◽

Room Temperature ◽

Thermodynamic Characteristics ◽

Liquid Nitrogen Temperature ◽

Analysis Data ◽

Thermal Excitation

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.

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Nanocomposite Polyurethane Foams Via POSS Blends

MRS Proceedings ◽

10.1557/proc-733-t1.6 ◽

2002 ◽

Vol 733 ◽

Author(s):

Brock McCabe ◽

Steven Nutt ◽

Brent Viers ◽

Tim Haddad

Keyword(s):

High Temperature ◽

Sample Preparation ◽

Room Temperature ◽

Focused Ion Beam ◽

Ion Beam ◽

Polyurethane Foams ◽

Development Projects ◽

Polymer Systems ◽

Polyurethane Resin ◽

Military Development

AbstractPolyhedral Oligomeric Silsequioxane molecules have been incorporated into a commercial polyurethane formulation to produce nanocomposite polyurethane foam. This tiny POSS silica molecule has been used successfully to enhance the performance of polymer systems using co-polymerization and blend strategies. In our investigation, we chose a high-temperature MDI Polyurethane resin foam currently used in military development projects. For the nanofiller, or “blend”, Cp7T7(OH)3 POSS was chosen. Structural characterization was accomplished by TEM and SEM to determine POSS dispersion and cell morphology, respectively. Thermal behavior was investigated by TGA. Two methods of TEM sample preparation were employed, Focused Ion Beam and Ultramicrotomy (room temperature).

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NICROFER 5520 Co

Alloy Digest ◽

10.31399/asm.ad.ni0480 ◽

1995 ◽

Vol 44 (3) ◽

Keyword(s):

High Temperature ◽

Chemical Composition ◽

Physical Properties ◽

Tensile Properties ◽

High Temperatures ◽

Heat Treating ◽

High Temperature Corrosion ◽

Creep Properties ◽

Nickel Chromium ◽

Temperature Performance

Abstract NICROFER 5520 Co is a nickel-chromium-cobalt-molybdenum alloy with excellent strength and creep properties up to high temperatures. Due to its balanced chemical composition the alloy shows outstanding resistance to high temperature corrosion in the form of oxidation and carburization. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ni-480. Producer or source: VDM Technologies Corporation.

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FANSTEEL 85 METAL

Alloy Digest ◽

10.31399/asm.ad.cb0007 ◽

1981 ◽

Vol 30 (6) ◽

Keyword(s):

High Temperature ◽

Physical Properties ◽

Creep Strength ◽

Room Temperature ◽

Elevated Temperatures ◽

Base Alloy ◽

Heat Treating ◽

Good Combination ◽

Bend Strength ◽

Temperature Performance

Abstract FANSTEEL 85 METAL is a columbium-base alloy characterized by good fabricability at room temperature, good weldability and a good combination of creep strength and oxidation resistance at elevated temperatures. Its applications include missile and rocket components and many other high-temperature parts. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and bend strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cb-7. Producer or source: Fansteel Metallurgical Corporation. Originally published December 1963, revised June 1981.

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MAGNESIUM AZ31B

Alloy Digest ◽

10.31399/asm.ad.mg0053 ◽

1962 ◽

Vol 11 (9) ◽

Keyword(s):

High Temperature ◽

Magnesium Alloy ◽

Physical Properties ◽

Room Temperature ◽

Heat Treating ◽

General Purpose ◽

Bearing Strength ◽

Temperature Performance ◽

Wrought Magnesium Alloy ◽

Metal Products

Abstract Magnesium AZ31B is a general purpose wrought magnesium alloy for room temperature service. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive, shear, and bearing strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Mg-53. Producer or source: The Dow Metal Products Company.

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