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The axisymmetric temperature fields and cyclic elastic-plastic stress-strain fields and Mises' equivalent stress-strain fields of 12V180 and 42-160 engines' pistons were calculated by the program “ADINAT/ADINA”. The tests of thermal-mechanical and isothermal low-cycle fatigue at elevated temperatures were carried out with the cylindrical notched specimens according to the “start-stop” wave. The results...
The benefits shown in the reliability performance when using the low Ag solder in BGA package has been known due to its intrinsic characteristic. In this study, SAC alloy with the dopant D1 and D2 respectively are selected to compare with the widely-used solder alloy, SAC105, from the perspective of the thermal fatigue fracture. The 0.5mm-pitch TFBGA packages on Halogen-free FR4 PCB pre-treated at...
Physics-of-failure (POF) prognostic model is a key technique of prognostics and health management (PHM) which plays critical roles for remaining life assessment of the products. The recent developments in POF based stress-damage model on thermal fatigue and vibration fatigue of solder joints were summarized. Numerous fatigue stress-damage models were proposed such as stress-fatigue model, strain-fatigue...
Most accelerated temperature cycling (ATC) tests reported the observations that SnAgCu (SAC) solders have better thermal fatigue reliability than SnPb solders due to their lower creep strain rate. But material studies revealed that this is true only when stress level is below a certain level. When the stress level in the solder increases, eventually the creep strain rate of SAC solder may outgrow...
Semiconductors are solids whose electrical conductivity is intermediate between that of a conductor and an insulator. Semiconductor devices are active devices that consume, accumulate, and discharge the supplied electric power. They are used as electronic or power devices. The former are employed in the control systems of electrical products such as mobile phones and computers, which are controlled...
Thermal fatigue lifetime of the Fan-in Package on Package (FiPoP) was analyzed based on the plastic strain model by finite element analysis (FEA). Both the stress and strain of FBGA and PBGA solder joints were studied under thermal cycling. It was found that the outmost solder joint on the PCB was the most dangerous position. The fatigue lifetime for the key solder joint on the PCB was estimated using...
CBGA (ceramic ball grid array) is one kind of advanced package for FPGA, which can fulfill the demands of high interconnect density, high thermal and electronic performance, high chip-assembling yields, high reliability. But in multiple loading environments, CBGA has the invalidation mode of solder joint thermal-mechanical failure, which will influence the long term reliability of FPGA circuits. But...
The aim of this study is to investigate the creep fatigue behavior of stainless steel materials. In the low cycle thermal fatigue life model, Manson's Universal Slopes equation was used as an empirical correlation which relates fatigue endurance to tensile properties. Fatigue test data were used in conjunction with different modes to establish the relationship between temperature and other parameters...
SnAgCu solder is fast becoming a reality in electronic manufacturing during to marketing and legislative pressure. This paper studies the thermal fatigue life of flip chip by the application of thermal fatigue life prediction model. The required life prediction model for SnAgCu solder joint is based on fatigue-creep interaction damage theory. In same test condition, the actual life of flip chip is...
A continuum damage model is proposed for Sn3.0Ag0.5Cu solder alloy in pure shear conditions. Experimental tests were performed on specific torsion samples to adjust material parameters of the continuum damage model. The main advantage of this method is to introduce damage process in the mechanical behaviour law of SnAgCu solder. Damage process highly affects the mechanical behaviour of solder alloy...
PTH(plated through hole) integrity becomes primary PCB(printed circuit board) reliability concern during component mounting process or subsequent field condition. Main cause of PTH failures is traced to significant differences in the amount of thermal expansions between copper barrel and surrounding glass epoxy. When the different expansion due to thermal stresses makes strain that exceeds the fracture...
Voids in ball grid array (BGA) solder joints have been considered as a main problem in lead-free soldering process. Compared with tin-lead solder, worse wetting capability of lead-free solder aggravates the formation of voids. Along with the wide application of BGA packages and the transition of lead-free soldering, the effect of voids on the reliability of BGA solder joints has been concerned. In...
Thermal fatigue life of PBGA (plastic ball grid array) solder joint on the FPC (flexible printed circuit) was analysed based on finite element analysis. According to symmetry theory, a quarter finite element model of 144-PIN PBGA was established. Both the stress and strain of lead and lead-free PBGA solder joints on the flexible PCB with the basic material of polyimide were studied by non-linear finite...
This paper deals with thermal fatigue of solder joints as function of oxygen concentration at the interconnection. Thermal fatigue occurs in the field as a result of computer on/off cycles, producing strains in the solder joints due to the thermal mismatch between the interconnected materials, i.e., chip and substrate. The time-to-failure increases with decreasing oxygen content, and is a function...
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