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This paper aims to present two Anand’s model parameter sets for the multilayer silver–tin (AgSn) transient liquid phase (TLP) foils.

The AgSn TLP test samples are manufactured using pre-defined optimized TLP bonding process parameters. Consequently, tensile and creep tests are conducted at various loading temperatures to generate stress–strain and creep data to accurately determine the elastic properties and two sets of Anand model creep coefficients. The resultant tensile- and creep-based constitutive models are subsequently used in extensive finite element simulations to precisely survey the mechanical response of the AgSn TLP bonds in power electronics due to different thermal loads.

The response of both models is thoroughly addressed in terms of stress–strain relationships, inelastic strain energy densities and equivalent plastic strains. The simulation results revealed that the testing conditions and parameters can significantly influence the values of the fitted Anand coefficients and consequently affect the resultant FEA-computed mechanical response of the TLP bonds. Therefore, this paper suggests that extreme care has to be taken when planning experiments for the estimation of creep parameters of the AgSn TLP joints.

In literature, there is no constitutive modeling data on the AgSn TLP bonds.

The purpose of this paper is to examine an integrative model combining teachers’ perceptions of transformational leadership practices (TLPs) and different subsystems of the social ecological model (SEM) within the context of country culture (US vs Israel).

A quantitative study was conducted among 615 Israeli teachers and 541 US teachers. The leadership practices inventory (LPI) questionnaire was used, and analyses focused on the interaction effects of ecological subsystems and country on teachers’ perceptions of TLP.

Results indicated that some universal leadership aspects appear in both the USA and Israel, with modeling the way being most dominant and Challenging the Process least dominant. However, the findings also indicated some specific national leadership aspects. For example, Israeli teachers perceive their school principals’ TLP to be significantly higher than do US teachers in all five dimensions. In addition, the study indicated significant differences between Israel and the USA regarding aspects of TLP, after taking school level into account. The results are explained by Hofstede’s culture dimensions.

This study focuses on teachers’ perceptions of TLP in relation to SEM, which has been largely ignored in educational leadership studies. The findings may help to develop an integrative policy related to both TLP and SEM, which will enhance the impact that school leadership may have in both countries, taking the cultural context into consideration.

A tension leg platform (TLP) is a vertically moored, floating structure which is normally used for offshore oil/gas production. However, these types of structures can be damaged by vibration responses that are too large. The purpose of this paper is to consider the influence of the external waves on oceanic structures.

A mathematical model of an ocean environment was constructed, in which wave‐induced flow fields cause structural surge motion, then solutions to the mathematical model were analytically derived.

The Takagi‐Sugeno (T‐S) fuzzy model is employed in the approximation of the oceanic structure. The stability analysis of the TLP system is carried out using the Lyapunov direct method.

The dependence of the wave‐induced flow field and its resonant frequency on the wave characteristics and the structural properties of the platform, which include width, thickness and mass, can be drawn using a parametric approach.

Mathematical modeling is applied to find the wave‐induced displacement due to the surge motion. The vibration of the mechanical motion of the platform structure caused by wave force is also discussed.

The purpose of this paper is to investigate the thermomechanical response of four well-known lead-free die attach materials: sintered silver, sintered nano-copper particles, gold-tin solders and silver-tin transient liquid phase (TLP) bonds.

This examination is conducted through finite element analysis. The mechanical properties of all die attach systems, including elastic and Anand creep parameters, are obtained from relevant literature and incorporated into the numerical analysis. Consequently, the bond stress-strain relationships, stored inelastic strain energies and equivalent plastic strains are thoroughly examined.

The results indicate that silver-tin TLP bonds are prone to exhibiting higher inelastic strain energy densities, while sintered silver and copper interconnects tend to possess higher levels of plastic strains and deformations. This suggests a higher susceptibility to damage in these metallic die attachments. On the other hand, the more expensive gold-based solders exhibit lower inelastic strain energy densities and plastic strains, implying an improved fatigue performance compared to other bonding configurations.

The utilization of different metallic material systems as die attachments in power electronics necessitates a comprehensive understanding of their thermomechanical behavior. Therefore, the results of the present paper can be useful in the die attach material selection in power electronics.

In power electronics, there are various metallic material systems used as die attachments. The complete understanding of the thermomechanical behavior of such interconnections is very important. Therefore, this paper aims to examine the thermomechanical response of four famous die attach materials, including sintered silver, sintered nano-copper particles, gold-tin solders and silver-tin transient liquid phase (TLP) bonds, using nonlinear finite element analysis.

During the study, the mechanical properties of all die attach systems, including elastic and viscoplasticity parameters, are obtained from literature studies and hence incorporated into the numerical analysis. Subsequently, the bond stress–strain relationships, stored inelastic strain energies and equivalent plastic strains are thoroughly examined.

The results showed that the silver-tin TLP bonds are more likely to develop higher inelastic strain energy densities, while the sintered silver and copper interconnects would possess higher plastic strains and deformations. Suggesting higher damage to such metallic die attachments. The expensive gold-based solders have developed least inelastic strain energy densities and least plastic strains as well. Thus, they are expected to have improved fatigue performance compared to other bonding configurations.

This paper extensively investigates and compares the mechanical and thermal response of various metallic die attachments. In fact, there are no available research studies that discuss the behavior of such important die attachments of power electronics when exposed to mechanical and thermomechanical loads.

Because of the need for electronics use at temperatures beyond 150°C, high temperature resistant interconnection technologies like transient liquid phase (TLP) soldering and silver sintering are being developed which are not only replacements of high-lead solders, but also open new opportunities in terms of temperature resistance and reliability. The paper aims to address the thermo-mechanical reliability issues that have to be considered if the new interconnection technologies will be applied.

A TLP soldering technique is briefly introduced and new challenges concerning the thermo-mechanical reliability of power devices are worked out by numerical analysis (finite element simulation). They arise as the material properties of the interconnect materials differ substantially from those known for soft solders. The effective material responses of the new materials are determined by localized unit cell models that capture the inhomogeneous structure of the materials.

It is shown that both the TLP solder layer and the Ag-sinter layer have much less ductility and show less creep than conventional soft solders. The potential failure modes of an assembly made by TLP soldering or Ag sintering change. In particular, the characteristic low cycle fatigue solder failures become unlikely and are replaced either by metallization fatigue, brittle failure of intermetallic compound, components, or interfaces.

A variety of new failure risks, which have been analyzed theoretically, can be avoided only if they are known to the potential user of the new techniques. It is shown that an optimal reliability will be strongly dependent on the actual assembly design.

This paper aims to investigate Cu/SnAgCu/Cu transient liquid phase (TLP) bonding with different thicknesses for three-dimensional (3D) integrated circuit (IC).

This paper includes experiments and finite element simulation.

The growth rate of the intermetallic compound layer during TLP soldering was calculated to be 0.6 μm/s, and the small scallop-type morphology Cu₆Sn₅ grains can be observed. With the decrease in thickness in solder joint, the thickness of intermetallic compounds represents the same size and morphology, but the size of eutectic particles (Ag₃Sn, Cu₆Sn₅) in the matrix microstructure decrease obviously. It is found that with the increase in thickness, the tensile strength drops obviously. Based on finite element simulation, the smaller value of von Mises demonstrated that the more reliability of lead-free solder joints in 3D IC.

The Cu/SnAgCu/CuTLPbondingwithdifferentthicknessesfor3D IC was investigated.

This paper aims to deal with the problem of the global stabilization for a class of tension leg platform (TLP) nonlinear control systems.

It is well-known that, in general, the global asymptotic stability of the TLP subsystems does not imply the global asymptotic stability of the composite closed-loop system.

An effective approach is proposed to control chaos via the combination of fuzzy controllers, fuzzy observers and dithers.

If a fuzzy controller and a fuzzy observer cannot stabilize the chaotic system, a dither, as an auxiliary of the controller and the observer, is simultaneously introduced to asymptotically stabilize the chaotic system.

Thus, the behavior of the closed-loop dithered chaotic system can be rigorously predicted by establishing that of the closed-loop fuzzy relaxed system.