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As complex multi-layered packaging becomes more common in microelectronic design, delamination remains a prominent failure mechanism due to coefficient of thermal expansion mismatch. Numerous studies have investigated interfacial cracking in microelectronic packages. These studies commonly use classical interfacial fracture mechanics analyses, but such analyses require knowledge of starter crack size,...
The wafer level ball grid array (WLBGA), a silicon die-size package, offers the small form factor and highperformance packaging solution. Good board-level reliability under drop impact is achieved on account if its light weight. There is, however, a limitation on the reliability of the solder joint at board level, subject to thermal cyclic loading. This places a limit on the silicon die-size window...
Presence of a thermal enabling load applied to Ball Grid Array (BGA) components creates a distinctive set of evaluations to be completed for reliability of solder joints (SJ) that connect the BGA to the board. This becomes especially relevant for newer technologies that drive to smaller component form factors. In this comprehensive study, a computational mechanics based Design of Experiments approach...
Transient liquid phase (TLP) soldering is one option for high temperature interconnects with the advantage of processing conditions being close to those for conventional soldering. In the Cu-Sn system addressed in the paper, a high post-processed melting point of the solder interconnects is achieved due to the formation of Cu6Sn5 and Cu3Sn intermetallic compounds (IMC). A specific low melting solder...
Degeneration of the intervertebral disc (IVD) is affecting nearly 80% of the population at some point during their life. This degeneration is a cascading event and a primary cause of lower back pain. A healthy IVD primarily depends on diffusion through the cartilage endplates for its nutrition, however, transport is reduced if the vertebral endplates become sclerotic or proteoglycan content in the...
In this paper, a printed circuit board (PCB) carrying surfacemounted devices (SMD) subjected to impact or vibration loads applied to its support contour is considered. A model-based prognosis approach is employed to assess the remaining useful life (RUL) of the ball-grid-array (BGA) solder joint interconnections. The approach deals with the interaction (coupling) of the “fast” PCB vibration model...
The paper presents the finite element code LOGOS for high performance computing developed in Russian Federal Nuclear Center VNIIEF. Among other, its functionality intended to numerical analysis of quasi-static strength problems. The description of main procedures and algorithms that allow accounting both physical and geometrical non-linear effects and contact interaction, is given. At present, the...
In this paper buckling loads and modes of an Euler beam made of graphene are considered. An eigenvalue problem is formulated with an additional parameter representing material's elastoplasticity. Analytical approximate solution using the perturbation method is presented. This approximate solution is used as a basis for an iterative finite difference scheme to develop a more accurate solution. Deflection...
Developing of the Ring-Core method for residual stress measurement requires complex simulation analysis. Properly designed simulation model and precise strain gage reading is needed for developing the evaluation methods. The paper deals about software made for the connection of simulation program SolidWorks and Excel spreadsheet using Visual Basic scripts.
The new and promising field of soft robotics has many open areas of research such as the development of an exhaustive theoretical and methodological approach to dynamic modeling. To help contribute to this area of research, this paper develops a dynamic model of a continuum soft robot arm driven by cables and based upon a rigorous geometrically exact approach. The model fully investigates both dynamic...
Cellulose-based components constitute the bulk of the current insulation for transformers. Cellulose is an organic polymer material which combines excellent electrical properties and good mechanical performance. As a polymeric material, cellulose is very sensitive to moisture and temperature. These factors can influence the electrical and mechanical performance of a transformer throughout its lifetime...
One of the method to measure very small axial loads (<1kg) is to use thin metallic strip with strain gage and associated signal conditioning circuit. However, small loads generate very little amount of strain and hence, use of metallic strain gages require very large amplification by signal conditioning circuit. Semiconductor strain gages are highly temperature sensitive and hence are not preferred...
The performance of IGBT (Insulated Gate Bipolar Transistor) power module under power cycling test is investigated based on a FEA (Finite Element Analysis) method. Critical point of solder fatigue has been discovered through analysis. Thermal cycling test has also been simulated as a comparison. The impact of power module parameters, such as power dissipation of chip, cycle period, solder layer thickness...
We report on measurement and modeling of dynamic energy harvesters based on oscillating piezoelectric cantilevers, along with careful calibration of energy conversion properties of such devices in their dynamic responses. We employ thin-film lead zirconate titanate (PZT)-based cantilevers fabricated by laser micromachining, with efficient proof masses enabled by a heavy alloy with a low melting temperature...
The load capacity of a hook (latch) which is a component of lock mechanism plays a key role in the safety of locking. A practical method to assess the load acting on the hook is presented. Although the use of static load testing method could get some veritably results, it has a limitation that the data measured in the test could not fully reflect the hook's load capacity. Although the use of finite...
This paper describes finite element analysis(FEA) for the body frame of 200 meter class multi-legged subsea robot, Crabster200(CR200). The body frame of CR200 is designed as a rib cage in order to disperse applied external loads and is made of carbon fiber reinforced plastic(CFRP) Therefore, the frame is lighter and stronger than a frame of the other conventional materials. In order to perform the...
The structure system of the steel roof of Tianjin Grand Theater is complex, and the stress distribution changes constantly in the unloading process. Through the simulation analysis of the whole unloading process, the stress distribution and deformation of the structure in different unloading steps were obtained. Besides, member configuration was predicated and preset in order to satisfy the target...
Organic laminate substrate is one of the largest constituent volume-wise in area array packages, and it plays a key role in overall package stress and warpage evolutions during fabrication process and in service conditions. In order to accurately estimate the influences of substrate on stress and warpage, it is important to characterize the time-dependent constitutive behavior of the organic substrate...
Compliant interconnects are able to mechanically decouple die from substrate and are helpful in reducing thermally-induced stresses in the die. In this paper, we report drop-test modeling of die-substrate assemblies with compliant interconnects. Simulations using explicit ANSYS/LS-DYNA® solver were carried out to mimic typical experimental conditions and to gain a better understanding of the overall...
Problem statement: The purposes of this study are twofold: First, to check the failures in Finite Element model of 2010 Toyota Yaris Sedan driver seat, when loaded as per Federal Motor Vehicle Safety Standards 207/210. And second, to enhance the strength of failure component of seat to pass the standards 207/210. Approach: Toyota Yaris Sedan Passenger Vehicle driver seat model is taken from the National...
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