Reliability Study of High-Temperature-Resistant Mounting Structure Considering Shear Behavior of Joint Layer

2009 ◽  
Author(s):  
Masanori Yamagiwa ◽  
Masato Fujita ◽  
Qiang Yu ◽  
Hiromi Sugihara
Keyword(s):  
High Temperature ◽  
Thermal Cycle ◽  
Coefficient Of Thermal Expansion ◽  
Shear Behavior ◽  
Nano Particles ◽  
Image Correlation ◽  
New Method ◽  
Shear Direction ◽  
Element Analysis ◽  
Temperature Sinter

Wide band gap semiconductor devices such as Silicon Carbide (SiC) or Gallium Nitride (GaN) capable of operation at high temperature over 300 degrees offer the potential of higher performance with reduced size, weight and eventually cost in power electronics equipment. For these high-temperature-resistant devices, the authors have proposed a new chip mounting structure that the stress relaxation function rests with the circuit metal on the substrate rather than the joint layer. In this study, to evaluate thermal fatigue of the new structure precisely, material properties of the high-temperature-resistant joint layer were measured by a new method and this method enabled analysis using measured properties. The joint layer which became very thin was formed by a low temperature sinter technology using silver (Ag) nano particles. The shear test to obtain the nonlinear properties of the joint layer was carried out by a proposed new method using bimetal fixtures which are composed of two materials whose Coefficient of Thermal Expansion (CTE) is different. Displacement of shear direction on the joint layer formed between the fixtures can be generated by heating the fixtures. Micro displacement was measured by Digital Image Correlation Method (DICM) using optical microscope and minute load on the joint layer was detected by strain gauge attached at fixture. Using the properties of the joint layer obtained as the test results, shear behavior on the chip joint was evaluated by Finite Element Analysis (FEA). Furthermore, harsh Thermal Cycle Test between −50 and 300 degree Celsius was carried out in the samples as the same structure as FEA model. From these results, the fatigue mechanism became clear and an improvement of the thermal cycle life was discussed.

scholarly journals Laue-DIC: a new method for improved stress field measurements at the micrometer scale

2015 ◽  
Vol 22 (4) ◽  
pp. 980-994 ◽  
Author(s):  
J. Petit ◽  
O. Castelnau ◽  
M. Bornert ◽  
F. G. Zhang ◽  
F. Hofmann ◽  
...  
Keyword(s):  
Standard Technique ◽  
Field Measurements ◽  
European Synchrotron Radiation Facility ◽  
Image Correlation ◽  
New Method ◽  
Polycrystalline Materials ◽  
Element Analysis ◽  
Analytical Functions ◽  
Local Stresses ◽  
Micrometer Scale

A better understanding of the effective mechanical behavior of polycrystalline materials requires an accurate knowledge of the behavior at a scale smaller than the grain size. The X-ray Laue microdiffraction technique available at beamline BM32 at the European Synchrotron Radiation Facility is ideally suited for probing elastic strains (and associated stresses) in deformed polycrystalline materials with a spatial resolution smaller than a micrometer. However, the standard technique used to evaluate local stresses from the distortion of Laue patterns lacks accuracy for many micromechanical applications, mostly due to (i) the fitting of Laue spots by analytical functions, and (ii) the necessary comparison of the measured pattern with the theoretical one from an unstrained reference specimen. In the present paper, a new method for the analysis of Laue images is presented. A Digital Image Correlation (DIC) technique, which is essentially insensitive to the shape of Laue spots, is applied to measure the relative distortion of Laue patterns acquired at two different positions on the specimen. The new method is tested on anin situdeformed Si single-crystal, for which the prescribed stress distribution has been calculated by finite-element analysis. It is shown that the new Laue-DIC method allows determination of local stresses with a strain resolution of the order of 10−5.

scholarly journals A New Method Combining Finite Element Analysis and Digital Image Correlation to Assess Macroscopic Mechanical Properties of Dentin

Materials ◽  
2015 ◽  
Vol 8 (2) ◽  
pp. 535-550 ◽  
Author(s):  
Wenlong Wang ◽  
Nicolas Roubier ◽  
Guillaume Puel ◽  
Jean-Marc Allain ◽  
Ingrid Infante ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Image Correlation ◽  
New Method ◽  
Element Analysis

Thermal Fatigue Reliability of High-Temperature-Resistant Joint for Power Devices

2009 ◽  
Author(s):  
Hiromi Sugihara ◽  
Masanori Yamagiwa ◽  
Masato Fujita ◽  
Toshikazu Oshidari ◽  
Qiang Yu
Keyword(s):  
High Temperature ◽  
Thermal Fatigue ◽  
Critical Issue ◽  
Nano Particles ◽  
Fatigue Reliability ◽  
Analysis Model ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Higher Temperature ◽  
Micro Structures

The power electronics equipments for Electric vehicles such as the inverter are strongly demanded on downsizing and weight reduction. For these requirements, Silicon Carbide (SiC) devices are receiving particular attention. SiC devices are characterized by lower-loss and higher temperature operation compared with Si devices. Using the devices under high temperature, the cooling equipments can be miniaturized. However, a function of stress relaxation that the existing solder has is difficult to be expected in a high-temperature-resistant joint layer for SiC devices, because the joint layer is generally hard. So, the authors have proposed a new mounting structure that a metal circuit on a substrate has the function instead of the joint layer. In this study, high-temperature-resistant mounting structures that the chip was bonded by low temperature sintering method using Ag nano-particles to substrate with Ag/Ni plating are prepared. Thermal Cycle Test (TCT) using these samples of harsh temperature range was conducted. As a result a new critical issue on the chip joint was identified. To clarify the thermal fatigue mechanism, the Finite-Element-Analysis (FEA) was carried out. The analysis model simulated a thin layer of Ag/Ni plating and the high-temperature-resistant joint layer. By the FEM results, the thermal fatigue, particularly occurring crack, was affected by the micro structures.

A Measurement Method Using Bi-Metal Fixture for Non-Linear Property of Thin Layer Joint

2008 ◽  
Author(s):  
Masanori Yamagiwa ◽  
Qiang Yu ◽  
Masato Fujita
Keyword(s):  
High Temperature ◽  
Thin Layer ◽  
Cooling System ◽  
The State ◽  
Image Correlation ◽  
Nonlinear Material ◽  
Shear Direction ◽  
Ag Nanoparticle ◽  
Bulk Specimen ◽  
Nonlinear Properties

Silicon Carbide Power (SiC) Devices which are operable under high temperature are focused, since the cooling system for the power modules can be miniaturized. In the conventional power devices, the thermal stress that is caused by the thermal expansion mismatch between the Si chip and the substrate can be absorbed by the deformation of solder joint. As a result, the thermal fatigue reliability of the conventional structures is secured. However, the solder materials cannot be used to mount the high temperature operable device like SiC because the operating temperature is higher than their melting temperature. In this study, a kind of Ag nanoparticle thin layer joint is proposed to the mount high temperature operable device. The feature of the Ag nanoparticle is to joint the chip on the substrate by low temperature sintering, and the melting point of the thin layer after mounting process is equal to the bulk Ag. To evaluate the reliability potential of proposed structure, the nonlinear material properties of the thin layer is required. However, it is difficult to measure these properties by the current method. Since it is considered the thin layer has different micro structure from that of the bulk Ag, and it is difficult to prepare a bulk specimen made of the Ag nanoparticle material. Therefore, it is necessary to measure the properties of Ag nanoparticle in the state of a thin layer. In this research, a new approach was proposed to measure the nonlinear properties in the state of thin layer by using a bi-metal fixture which is composed of two different materials whose CTEs are different. When the fixture is heated, micro displacement can be generated between two materials. The thin layer which is formed between the two metals in the fixture deformed in shear direction by the displacement. During the heating, the shear deformation of the thin layer is measured by a digital image correlation method. The load on the thin layer is measured by strain gauge attached at fixture. In this study, the nonlinear properties of Ag nanoparticle thin layer were measured by this method. In addition, properties of solder were measured by this method too as a reference, and the results were compared with the property of bulk solder to confirm the accuracy of the method using bi-metal fixture.

Warpage Evaluation of High-Temperature Sandwich-Structured Power Module for SiC Power Semiconductor Devices

2015 ◽  
Vol 12 (3) ◽  
pp. 153-160 ◽  
Author(s):  
Takeshi Anzai ◽  
Yoshinori Murakami ◽  
Shinji Sato ◽  
Hidekazu Tanisawa ◽  
Kohei Hiyama ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Cycle ◽  
Coefficient Of Thermal Expansion ◽  
Fabrication Process ◽  
Power Module ◽  
Ceramic Substrates ◽  
Soldering Temperature ◽  
Power Semiconductor ◽  
Power Modules ◽  
High Temperature Operation

This article presents a sandwich-structured SiC power module that can be operated at 225°C. The proposed power module has two ceramic substrates that are made of different materials (Si3N4 and Al2O3). The SiC devices are sandwiched between these ceramic substrates. The module also has a baseplate soldered onto the ceramic substrate. Conventional power modules use baseplate materials with a large coefficient of thermal expansion (CTE), for example, Cu (17–18 ppm/°C and Al (23–24 ppm/°C). In the fabrication process, the soldering temperature reaches 450°C because Au-Ge eutectic solder is used. A problem was found in the fabrication process of the module because of the high soldering temperature and CTE mismatches of the components. Furthermore, for high-temperature operation, a thermal cycle of −40°C to 250°C will be needed to ensure reliability and it is important to decrease the warpage of the module during the thermal cycle. By using stainless steel (CTE: 10 ppm/°C) for the baseplate, the warp-age measured at room temperature was reduced to one-third that of a module using a Cu baseplate. Further, the warpage displacement from 50°C to 250°C was also reduced.

NILO ALLOY 36

Alloy Digest ◽  
1987 ◽  
Vol 36 (8) ◽  
Keyword(s):  
Thermal Expansion ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Surface Treatment ◽  
Constant Coefficient ◽  
Coefficient Of Thermal Expansion ◽  
Heat Treating ◽  
Temperature Performance ◽  
Iron Nickel

Abstract NILO alloy 36 is a binary iron-nickel alloy having a very low and essentially constant coefficient of thermal expansion at atmospheric temperatures. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Fe-79. Producer or source: Inco Alloys International Inc..

UNISPAN LR35

Alloy Digest ◽  
1971 ◽  
Vol 20 (1) ◽  
Keyword(s):  
Thermal Expansion ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Coefficient Of Thermal Expansion ◽  
Heat Treating ◽  
Temperature Performance ◽  
Operational Level

Abstract UNISPAN LR35 offers the lowest coefficient of thermal expansion of any alloy now available. It is a low residual modification of UNISPAN 36 for fully achieving the demanding operational level of precision equipment. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and surface treatment. Filing Code: Fe-46. Producer or source: Cyclops Corporation.

RED X-20

Alloy Digest ◽  
1960 ◽  
Vol 9 (2) ◽  
Keyword(s):  
Wear Resistance ◽  
Thermal Expansion ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Coefficient Of Thermal Expansion ◽  
Heat Treating ◽  
Aluminum Silicon Alloy ◽  
Temperature Performance

Abstract RED X-20 is a heat treatable hypereutectic aluminum-silicon alloy with excellent wear resistance and a very low coefficient of thermal expansion. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-89. Producer or source: Apex Smelting Company.

AA 4032

Alloy Digest ◽  
1990 ◽  
Vol 39 (7) ◽  
Keyword(s):  
Thermal Expansion ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Coefficient Of Thermal Expansion ◽  
Heat Treating ◽  
Temperature Performance

Abstract AA 4032 has a comparatively low coefficient of thermal expansion and good forgeability. The alloy takes on an attractive dark gray appearance when anodized which may be desirable in architectural applications. This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength as well as fatigue. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-305. Producer or source: Various aluminum companies.

scholarly journals Design of a Unique Device for Residual Stresses Quantification by the Drilling Method Combining the PhotoStress and Digital Image Correlation

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 314
Author(s):  
Miroslav Pástor ◽  
Martin Hagara ◽  
Ivan Virgala ◽  
Adam Kaľavský ◽  
Alžbeta Sapietová ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Experimental Testing ◽  
Digital Processing ◽  
Image Correlation ◽  
Optical Systems ◽  
Hole Drilling ◽  
Element Analysis ◽  
Thin Specimen ◽  
Comparison Of The Results

This paper presents a uniquely designed device combining the hole-drilling technique with two optical systems based on the PhotoStress and digital image correlation (DIC) method, where the digital image correlation system moves with the cutting tool. The authors aimed to verify whether the accuracy of the drilled hole according to ASTM E837-13a standard and the positioning accuracy of the device were sufficient to achieve accurate results. The experimental testing was performed on a thin specimen made from strain sensitive coating PS-1D, which allowed comparison of the results obtained by both methods. Although application of the PhotoStress method allows analysis of the strains at the edge of the cut hole, it requires a lot of experimenter’s practical skills to assess the results correctly. On the other hand, the DIC method allows digital processing of the measured data. However, the problem is not only to determine the data at the edge of the hole, the results also significantly depend on the smoothing levels used. The quantitative comparison of the results obtained was performed using finite element analysis.

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