Experimental Characterization of Material Properties of 63Sn37Pb Flip Chip Solder Joints

1998 ◽  
Vol 515 ◽  
Author(s):  
S. Wiese ◽  
F. Feustel ◽  
S. Rzepka ◽  
E. Meusel
Keyword(s):  
Material Properties ◽  
Flip Chip ◽  
Solder Joints ◽  
Material Behavior ◽  
Creep Model ◽  
Experimental Program ◽  
Published Data ◽  
Shear Tests ◽  
Cyclic Shear ◽  
Material Data

ABSTRACTThe paper presents new material data of real flip chip solder joints. A testing apparatus was designed to perform reversible shear tests on flip chip joints. In contrast to previous test setups for similar purposes this tester provides an infinite stiffness, a very high precision force (1 mN resolution) and displacement (20 nm resolution) measurement. The experimental program included cyclic shear tests for elastic plastic material data as well as a newly developed reversal creep and relaxation test for time depended material properties. A subsequent FEM simulation was applied to evaluate experimental raw data and to determine the parameters of material models provided by ANSYSTM. A user defined creep model had been added to the source code, in order to receive a convenient solder model for FE-Analysis of SnPb37 flip chip solder joints under thermomechanical stresses in electronic packages. The results of this study shows that the material behavior of flip chip solder joints is much more like that of bulk samples with a comparable micro structure than it is commonly believed up to now, because of the previously published data.

scholarly journals Cyclic and Permanent Shear Strains of a Soft Cohesive Soil Subjected to Combined Static and Cyclic Loading

2020 ◽  
Vol 10 (23) ◽  
pp. 8433
Author(s):  
Hernán Patiño ◽  
Rubén Galindo ◽  
Claudio Olalla Marañón
Keyword(s):  
Simple Shear ◽  
Cohesive Soil ◽  
Mediterranean Coast ◽  
Vertical Stress ◽  
Experimental Program ◽  
Shear Stresses ◽  
Shear Tests ◽  
Cyclic Shear ◽  
Shear Strains ◽  
Number Of Cycles

This paper refers to cyclic shear strains (γc) and permanent shear strains (γp) of a soft cohesive soil, when both monotonic shear stresses (τo) and cyclic shear stresses (τc) are applied. The research is backed by an extensive experimental program with 139 cyclic simple shear tests that included identification and classification tests. These cyclic simple shear tests were conducted under different levels of stresses, τo, before the cyclic phase. Laboratory tests were carried out on undisturbed samples from the Port of Barcelona, located in Spain on the Mediterranean coast, and characterized by a monotonic strength (τmax) approximately equal to 30% of the initial effective vertical stress (σ′ov). The samples were taken at depths between 29 and 52 m and correspond to an initial effective vertical stress between 277 and 413 kPa, respectively. In general, the results indicate that: (a) the combination of τo and τc controls the generation of γc and γp, (b) it is not always true that when τo/σ′ov + τc/σ′ov ≈ τmax/σ′ov, the soil reaches failure cyclically, and (c) empirical relations useful for design can be established between γc, γp, and the number of cycles (N), for different relationships varying (τo/σ′ov) between 0% and 25%.

Effects of Shear Cycling on the Mechanical Properties of SAC and SAC+X Lead Free Solder Joints

2019 ◽  
Author(s):  
Mohd Aminul Hoque ◽  
Md Mahmudur Chowdhury ◽  
Sa’d Hamasha ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall
Keyword(s):  
Mechanical Properties ◽  
Solder Joints ◽  
Coefficient Of Thermal Expansion ◽  
Real Life ◽  
Material Behavior ◽  
Lead Free ◽  
Lead Free Solder ◽  
Cyclic Shear ◽  
Mechanical Cycling ◽  
Free Solder

Abstract Solder joint reliability is a chief concern in electronic assemblies. Electronic packages consist of various materials, each having their own Coefficient of Thermal Expansion (CTE). When assembled packages experience high temperature gradients and thermal cycles, a mismatch in the CTE values brings about cyclic shear strains in the solder joints, which can ultimately lead to failure. Thus, it is important to understand the effects of shear cycling on the damage accumulated in solder joints. Previous studies conducted on the effect of mechanical cycling on the material behavior of lead free solders have been performed on bulk samples subjected to tension and compression. Our goal in this study was to determine the evolution of the mechanical properties of doped lead free solder joints when subjected to mechanical shear cycling. Experiments conducted on actual solder joints would help us gain a better understanding on the real life effects of shear cycling. The test specimens consisted of a 3 × 3 array of nine solder joints of approximately 0.75 mm diameter. With the aid of specially designed test fixtures, the specimens were gripped and then subjected to mechanical cycling in the shear using an Instron Micromechanical tester. Testing was performed on both SAC305 and SACX (SAC+Bi) solder joints. The joints were cycled for certain durations, and a nanoindentation system was used to measure the evolution of the mechanical properties (elastic modulus, hardness, creep rate) as a function of the number of shear cycles.

Identification of the anisotropic behavior of an aluminum alloy subjected to simple and cyclic shear tests

2018 ◽  
Vol 233 (3) ◽  
pp. 911-927 ◽  
Author(s):  
Daghfas Olfa ◽  
Znaidi Amna ◽  
Gahbiche Amen ◽  
Nasri Rachid
Keyword(s):  
Aluminum Alloy ◽  
Kinematic Hardening ◽  
Plastic Anisotropy ◽  
Mechanical Tests ◽  
Material Behavior ◽  
Isotropic Hardening ◽  
Cyclic Tests ◽  
Shear Tests ◽  
2024 Aluminum Alloy ◽  
Cyclic Shear

The main purpose of this paper is to study the behavior of the 2000 aluminum alloy series used particularly in the design of Airbus fuselage. The characterization of the mechanical behavior of sheet metal on 2024 aluminum alloy and its response to various loading directions under monotonic and cyclic tests are extremely considered. To solve this problem, first, an experimental platform which essentially revolves around mechanical tests and then a series of optical and transmission electronic visualizations have been carried out. These mechanical tests are monotonic and cyclic shear tests applied under the same conditions on the test specimens of 2024 aluminum alloy. Cyclic shear tests have been carried out in order to show the Bauschinger effect and then the kinematic hardening phenomenon. The hardening curves of the simple shear test showed the Portevin-Le Chatelier effect for all loading directions. Next, the experimental results obtained (Portevin-Le Chatelier and Bauschinger effects) are discussed and analyzed in relation to the microstructure of the studied alloy using an optical microscope and a transmission electron microscope. Thereafter, the plastic anisotropy is modeled using an identification strategy that depends on a plastic criterion, an isotropic hardening law, a kinematic hardening (linear and nonlinear) law, and an evolution law. More precisely, particular attention is paid to the isotropic power Hollomon law, the saturation Voce law, and the saturation Bron law. In the case of the cyclic tests, linear kinematic hardening described by the Prager law and nonlinear kinematic hardening expressed by the Armstrong–Frederick law are introduced. Finally, by smoothing the experimental hardening curves for the various simple and cyclic shear tests, a selection is made in order to choose the most appropriate law for the identification of the material behavior.

Characterization of Lead-Free Solders in Flip Chip Joints

2003 ◽  
Vol 125 (4) ◽  
pp. 531-538 ◽  
Author(s):  
S. Wiese ◽  
E. Meusel
Keyword(s):  
Flip Chip ◽  
Solder Joints ◽  
Constant Load ◽  
Shear Tests ◽  
Silicon Chips ◽  
Propagation Behavior ◽  
Apparent Activation Energies ◽  
Lead Free Solders ◽  
Crack Propagation Behavior

The creep and crack propagation behavior of SnAg3.5, SnAg4Cu0.5, and SnPb37 (as reference) was investigated on flip chip solder joints V=1×10−12 m3. The test specimen consisted of two silicon chips (3.3×3.3 mm), bonded to each other by four flip chip joints (one on each corner). The steady-state creep rate was determined by reversible constant load shear tests. The stress exponents were n=11 for Sn96.5Ag3.5, n=18 for Sn95.5Ag4Cu0.5, and n=2 for Sn63Pb37. The apparent activation energies were Q=79.8 kJ/mol for Sn96.5Ag3.5, Q=83.1 kJ/mol for Sn95.5Ag4Cu0.5, and Q=44.9 kJ/mol for Sn63Pb37. Microstructural analyses indicated that small precipitates of Ag3Sn and η-Cu6Sn5 intermetallics are responsible for the high values for n and Q that were found for the Sn96.5Ag3.5 and Sn95.5Ag4Cu0.5. The crack growth rate was determined by isothermal fatigue experiments on Sn63Pb37 and Sn95.5Ag4Cu0.5 flip chip solder joints. The flip chip solder joints were loaded with strain amplitudes ranging from Δε=0.3–4% and test frequencies f=0.0001-100 Hz at a temperature of T=300 K.

Input Data Influence on FEM Simulation of Steam Turbine Blades Materials Hot Forming

2013 ◽  
Vol 773-774 ◽  
pp. 79-88 ◽  
Author(s):  
Jan Džugan ◽  
Michal Zemko
Keyword(s):  
Computer Simulation ◽  
Chemical Composition ◽  
Input Data ◽  
Fem Simulation ◽  
Material Behavior ◽  
Hot Forming ◽  
Basic Material ◽  
Published Data ◽  
Material Data ◽  
Sample Component

Computer simulation/optimization is widely applied to hot forming processes nowadays. A crucial point of any kind of computer simulation is the input data. There are implemented in all FEM codes some basic material database, but usually for limited materials and material states. As the input data decide about the output results quality, it is always necessary to pay attention, what are the simulation inputs. The best solution, but not always possible, is direct measurement of materials parameters for considered material and state. As this is in some cases not possible, materials data are searched in alternative ways. One possibility is survey of published data in literature. A reliability of published data is difficult to assess, as there are usually not available sufficient information about the material investigated in publications. Other possibility how to obtain material data nowadays is utilization of programs predicting material behavior on the basis of chemical composition. One of currently available software for material properties prediction is JMatPro. The program is able to calculate a broad range of properties and behavior with the use of established thermodynamics models on the basis of chemical composition and the initial state of the considered material state. There can be for example determined thermophysical and physical properties (from room temperature to the liquid state), time-temperature-transformation/ continuous-cooling transformation diagrams, stress/strain diagrams, proof and tensile stress, hardness, coarsening of γ and γ , and creep. The current paper is dealing with the simulation of hot forming of steam blade made of Ti-based alloy. As an input material data used for FEM simulation are conventionally measured data and data obtained from JMatPro. With the use of both material data sets, a sample component forming is simulated. The results obtained from both simulations are subsequently compared with the results obtained from physical forming of the sample component. Performance of both simulations is discussed here, taking into account results of physical forming results.

scholarly journals Impact of residual stress evoked by pyramidal embossing on the magnetic material properties of non-oriented electrical steel

2021 ◽  
Author(s):  
Ines Gilch ◽  
Tobias Neuwirth ◽  
Benedikt Schauerte ◽  
Nora Leuning ◽  
Simon Sebold ◽  
...  
Keyword(s):  
Magnetic Material ◽  
Residual Stress ◽  
Magnetic Flux ◽  
Material Properties ◽  
Electrical Steel ◽  
Maximum Energy ◽  
Material Behavior ◽  
Electrical Machine ◽  
Element Analysis ◽  
Steel Sheets

AbstractTargeted magnetic flux guidance in the rotor cross section of rotational electrical machines is crucial for the machine’s efficiency. Cutouts in the electrical steel sheets are integrated in the rotor sheets for magnetic flux guidance. These cutouts create thin structures in the rotor sheets which limit the maximum achievable rotational speed under centrifugal forces and the maximum energy density of the rotating electrical machine. In this paper, embossing-induced residual stress, employing the magneto-mechanical Villari effect, is studied as an innovative and alternative flux barrier design with negligible mechanical material deterioration. The overall objective is to replace cutouts by embossings, increasing the mechanical strength of the rotor. The identification of suitable embossing geometries, distributions and methodologies for the local introduction of residual stress is a major challenge. This paper examines finely distributed pyramidal embossings and their effect on the magnetic material behavior. The study is based on simulation and measurements of specimen with a single line of twenty embossing points performed with different punch forces. The magnetic material behavior is analyzed using neutron grating interferometry and a single sheet tester. Numerical examinations using finite element analysis and microhardness measurements provide a more detailed understanding of the interaction of residual stress distribution and magnetic material properties. The results reveal that residual stress induced by embossing affects magnetic material properties. Process parameters can be applied to adjust the magnetic material deterioration and the effect of magnetic flux guidance.

Rapid diagnosis of electromigration induced failure time of Pb-free flip chip solder joints by high resolution synchrotron radiation laminography

2011 ◽  
Vol 99 (8) ◽  
pp. 082114 ◽  
Author(s):  
Tian Tian ◽  
Feng Xu ◽  
Jung Kyu Han ◽  
Daechul Choi ◽  
Yin Cheng ◽  
...  
Keyword(s):  
High Resolution ◽  
Synchrotron Radiation ◽  
Flip Chip ◽  
Solder Joints ◽  
Failure Time ◽  
Rapid Diagnosis

Crack Propagation Experiments on Flip Chip Solder Joints

1998 ◽  
Vol 515 ◽  
Author(s):  
S. Wiese ◽  
F. Feustel ◽  
S. Rzepka ◽  
E. Meusel
Keyword(s):  
Crack Propagation ◽  
Flip Chip ◽  
Solder Joints ◽  
Shear Loading ◽  
Displacement Curve ◽  
In Situ Experiments ◽  
Propagation Experiment ◽  
Crack Propagation Experiment ◽  
Number Of Cycles ◽  
Force Displacement

ABSTRACTThe paper presents crack propagation experiments on real flip chip specimens applied to reversible shear loading. Two specially designed micro testers will be introduced. The first tester provides very precise measurements of the force displacement hysteresis. The achieved resolutions have been I mN for force and 20 nm for displacement. The second micro tester works similar to the first one, but is designed for in-situ experiments inside the SEM. Since it needs to be very small in size it reaches only resolutions of 10 mN and 100nm, which is sufficient to achieve equivalence to the first tester. A cyclic triangular strain wave is used as load profile for the crack propagation experiment. The experiment was done with both machines applying equivalent specimens and load. The force displacement curve was recorded using the first micro mechanical tester. From those hysteresis, the force amplitude has been determined for every cycle. All force amplitudes are plotted versus the number of cycles in order to quantify the crack length. With the second tester, images were taken at every 10th … 100th cycle in order to locate the crack propagation. Finally both results have been linked together for a combined quatitive and spatial description of the crack propagation in flip chip solder joints.

Effect of entropy production on microstructure change in eutectic SnPb flip chip solder joints by thermomigration

2006 ◽  
Vol 89 (22) ◽  
pp. 221906 ◽  
Author(s):  
Fan-Yi Ouyang ◽  
K. N. Tu ◽  
Yi-Shao Lai ◽  
Andriy M. Gusak
Keyword(s):  
Entropy Production ◽  
Flip Chip ◽  
Solder Joints ◽  
Microstructure Change ◽  
Eutectic Snpb
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