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In this paper, the fine pitch ball grid array (FBGA) assembly with lead free solder was tested under thermal cycling condition. Finite element modeling and simulation was conducted. The microstructure designs of via in pad of substrate and through hole (via) in PCB under the solder joint were simulated. The solder mask definition (SMD) and non-solder mask definition (NSMD) on PCB board side was also...
A microelectromechanical system (MEMS) entirely made of crystalline oxides is presented. A suspended SrTiO3 (001) microcantilever is employed as flexible substrate for the deposition of epitaxial transition-metal oxide films. A strain-generator device for epitaxial oxide films can be fabricated. Strain at surface can be performed by bending downward the microcantilever. The mechanical properties of...
The drop reliability of mobile electronic products has become a major concern recently. Especially, system-in-package (SIP) like stacked-die-package and package-on-package may lead to increased the stress during drop impact due to their complicate structure. In this study, evaluation and prediction of the drop reliability for SIP was performed using modeling techniques. 3D-dynamic nonlinear finite...
Considering the high overload application of the pizeoceramic in the self-adapted bullet, a new piezoceramic actuator based on d33 structure is designed. In this paper, aluminum foil substrate and piezoceramic multilayer are introduced. According to the FEA simulation, this structure can afford a high load to 2000 g, which is definitely enough for the bullet application. The fabrication process was...
The following paper introduces the coventor ware design environment for SOI based piezoresistive sensor design. Fabrication process and characterization of designed sensors is also presented. The software package Coventor Ware has been used for design of mechanical and electrical characteristics of the structure. The tools enable design, modelling and successive modification of designed MEMS structures...
The aim of this study is to measure and simulate warpage of flip-chip PBGA packages under thermal loading (from room temperature to 260degC). In the experiments, a full-field shadow moire is used for measuring real-time out-of-plane deformations (warpages) on the substrate surfaces of the flip-chip packages under heating and cooling conditions. The elastic moduli (Es) and coefficients of thermal expansion...
In this paper, the backward compatibility solder joints were chosen in simulation of perimeter PBGA272 assembly. A double-symmetric plane FE model of a PBGA272 was established using the software ANSYS. Based on the maximum von Mises stress and von Mises strain, the position of the most danger solder joints were obtained under thermal cycle with the temperature condition from -40degC to 125degC (JESD22-A104-B...
A numerical modelling method for the analysis of solder joint damage and crack propagation has been described in this paper. The method is based on the disturbed state concept. Under cyclic thermal-mechanical loading conditions, the level of damage that occurs in solder joints is assumed to be a simple monotonic scalar function of the accumulated equivalent plastic strain. The increase of damage leads...
Nano-imprint forming (NIF) is among the most attractive manufacturing technologies offering high yield and low-cost fabrication of three-dimensional fine structures and patterns with resolution of few nanometres. Optimising NIF process is critical for achieving high quality products and minimising the risk of commonly observed defects. Using finite element analysis, the effect of various process parameters...
This paper considers mechanical stress and strain in a piezoresistive cantilever sensor under surface stress loading, which is the loading condition that occurs in biochemical sensing applications. Finite element simulations examine the piezoresistor sensitivity due to changes in cantilever length, width, and thickness, and piezoresistor size, location, and depth. A few unexpected results are found...
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