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High performance aluminium nitride water cooled heat sinks were fabricated and characterized. A variety of fabrication processes were employed to meet different cooling requirements. They include laser cut microchannel coolers for chip and multichip heat sinks as well as dry pressed pin fin heat sinks for power electronics. Thermal simulation was used to optimize the heat sink design.

For gravity dams built on foundations with directional joint sets, the seepage in the foundation possesses anisotropic characteristics and may have adverse effects on the foundation stability. A methodology for system reliability analysis of gravity dam foundations considering anisotropic seepage and multiple sliding surfaces is proposed in this paper.

Anisotropic seepages in dam foundations are simulated using finite element method (FEM) with the equivalent continuum model (ECM), and their effect on dam foundation stability is involved by uplift pressures acting on the potential sliding surfaces. The system failure probability of the dam foundation is efficiently estimated using Monte Carlo method (MCM) combined with response surface method (RSM).

The case study shows that it is necessary to consider the possibly adverse effect of anisotropic seepage on foundation stability of gravity dams and the deterministic analysis of the foundation stability may be misleading. The system reliability analysis of the dam foundation is justified, as the uncertainties in shear strength parameters of the foundation rocks and joint sets as well as aperture, connectivity and spacing of the joint sets are quantified and the system effect of the multiple potential sliding surfaces on the foundation reliability is reasonably considered.

(1) A methodology is proposed for efficient system reliability analysis of foundation stability of gravity dams considering anisotropic seepage and multiple sliding surfaces (2) The influence of anisotropic seepage on the stability of gravity dam foundation  is revealed (3) The influence of estimation errors of RSMs on the system reliability assessment of dam foundation is investigated.

The purpose of this paper is to develop a new alloying method for solders by using a metal organic modified flux in solder pastes.

This paper presents the impact of six metal organic compounds (Co, Fe, Al; stearate, oxalate, citrate) on the melting and solidification behaviour in comparison to the revealed microstructure.

It could be shown that Co and Al influence the supercooling whereas Fe exhibits no effect. Co reduces the supercooling of the cast of about 10 K and affects the nucleation. Al retards the solidification up to 185°C. Doping of the solder by flux containing metal organic compounds is successful and the alloying elements Co and Fe are found in the microstructure.

This paper provides a starting‐point for the new alloying method – so far only fluxes for solder pastes have been investigated.

The reactive alloying method enables the use of new alloying elements for solder pastes in unmodified soldering processes.

Because of new requirements related to the employment of lead‐free manufacturing and the diversity of components and metal finishes on high density printed circuit boards, better understanding and control of the reflow process is required in order to achieve acceptable yields and reliability of SMT assemblies. Accurate control of the temperature distributions within components and boards during the reflow process is one of the major requirements, especially in lead‐free assembly. This paper outlines a scheme for reflow modelling and presents an oven‐level model of the steady state flow‐field inside a reflow oven, which will be needed in subsequent transient analysis and small‐scale modelling. The model is constructed by utilising the advanced computational fluid dynamics (CFD) technology using commercial software. The computational results are discussed and compared with measured data.

In a high temperature tribometer, stationary carbon has been tested against different rotating ceramics (SiC, Si₃N₄, Al₂O₃, WC‐6Ni, MgO‐ZrO₂, (Ti, Mo)(C, N)) and stainless steel (DIN 1.4876). The rotating discs were grinded, polished and/or lapped. For most material combinations, the wear morphology is known from available literature. A transfer film with a typical wear pattern was found on the rotating disc. The combination of antimony graphite EK3245 against MgO‐ZrO₂ did not form carbonaceous transfer layer. Through advanced variation of the roughness up to R_pk=0.011 μm, the wear rate has been reduced to K_v ≈ 3.5×10⁻⁸ mm³/N m at a stable coefficient of friction in a “millirange” of μ∼0.008 for a sliding distance of 20.000 m.

In electronic packaging, when solid copper comes in contact with liquid solder alloy, the former dissolves and intermetallic compounds (IMCs) form at the solid‐liquid interface. The purpose of this paper is to study the effect of the presence of molybdenum nanoparticles on the dissolution of copper and the formation of interfacial IMC.

Cu wire having a diameter of 250 μm is immersed in liquid composite solders at 250°C up to 15 min. Composite solder was prepared by adding various amount of Mo nanoparticles into the Sn‐3.8Ag‐0.7Cu (SAC) solder paste. The dissolution behavior of Cu substrate is studied for SAC and Mo nanoparticles added SAC solders. The IMCs and its microstructure between the solder and substrate are analyzed by using conventional scanning electron microscope (SEM) and field emission SEM. The elemental analysis was done by using energy‐dispersive X‐ray spectroscopy.

Generally, the dissolution of the substrate increases with increasing immersion time but decreases with the increase of the content of Mo nanoparticles in the solder. The IMC thickness increases with increasing the reaction time but Mo nanoparticles can hinder the growth of IMC layer. The presence of Mo nanoparticle is found to be effective in reducing the dissolution of copper into SAC solder.

The paper shows that molybdenum nanoparticles in liquid SAC solders have a prominent effect on the substrate dissolution rate and the interfacial IMC between the SAC solder and copper substrate.

To investigate fluxless plasma ball bumping and effect of under bump metallization (UBM) thickness on joint properties using lead‐free solders.

A fluxless soldering process was investigated in this study using Ar‐10 percent H₂ plasma reflow. Balls made from two lead‐free solders (Sn‐3.5 weight percent Ag and Sn‐3.5 weight percent Ag‐0.7 weight percent Cu) were reflowed and, also Sn‐37 weight percent Pb as a reference. In particular, the effects of the UBM thickness on the interfacial metallurgical bonding and joint strength were studied. The UBM (Au/Cu/Ni/Al layers) thicknesses were 20 nm/0.3 μm/0.4 μm/0.4 μm and 20 nm/4 μm/4 μm/0.4 μm, respectively.

The experimental results showed that in the case of a thin UBM the shear strengths of the soldered joints were relatively low (about 19‐27 MPa) due to cracks observed along the bond interfaces. The thick UBM improved joint strength to 32‐42 MPa as the consumption of the Cu and Ni layers by reaction with the solder was reduced and hence the interfacial cracks were avoided. To provide a benchmark, reflow of the solders in air using flux was also carried out.

This paper provides information about the effect of UBM thickness on joint strength for plasma fluxless soldering to researchers and engineers.

This conceptual paper draws together an interdisciplinary approach to robo-advisors (RAs) as an example of an early and successful example of automated, programmed professional services.

Little is known about the forces driving this change in the delivery of professional service. This work explores the drivers of RAs, the degree of disruption incurred by the introduction of RAs, and how, as RAs advance, trust in algorithmic authority aids in legitimating RAs as smart information.

From the firms' perspective, the drivers include rebranding occasioned by the financial crisis (2008), the widening of the client base and the “on-trend” nature of algorithmic authority guided by artificial intelligence (AI) embedded in RAs. This examination of the drivers of RAs indicates that professional service automation is aligned with information society trends and is likely to expand.

Examining RAs as an indicator of the future introduction of programmed professional services suggests that success increases when the algorithmic authority in the programmed serves are minimally disruptive, trustworthy and expand the client base while keeping the knowledge domain of the profession under control of the industry.

Treating RAs as an early instance of successfully embedding knowledge in AI and algorithmically based platforms adds to the early stages of theory and practice in the monetization and automation of professional knowledge-based services.

The purpose of this study is to describe and analyse the effect of a set of determinants on initial trust and behavioural intention to use financial robo-advisors (FRAs).

The theory of perceived risk and the behavioural finance paradigm were used to develop a conceptual model of retail investors’ initial trust in FRAs. Data collected from 554 young retail investors (YRIs) from Sweden and Malaysia were analysed using structural equation modelling.

The results of this study indicate that the amount of public information, social media information-seeking and a rational decision style are significantly related to initial trust in FRAs, which in turn is significantly and positively related to the behavioural intention to use this technology. However, none of the risks under study significantly affect the initial trust in FRAs.

Information is vital to inducing YRIs to rely on FRAs, so the more public and social media information is available, the higher their intention to use this technology. However, YRIs vary in decision style, and the results suggest implementing a more sophisticated system than the current “one-size-fits-all” approach to YRI behaviour.

The empirical-based model enhances the knowledge of the initial phase of trust-building, when YRIs lack sufficient experience of FRAs. By collecting data from two countries, the study’s novel conclusions may help in developing effective FRA services for the youth segment.