In this paper, Moir e interferometry technique is used to measure the in situ displacement evolution of lead-free solder joint under electric current stressing. Large deformation was observed in solder joint under high density (10 A/cm) current stressing. The deformation was found to be due to electromigration in the solder joint. An electromigration constitutive model is applied to simulate de...

One of major reasons of failure of solder joints is known as the thermal fatigue. Also, The failure of the solder joints under the thermal fatigue loading is influenced by varying boundary conditions such as the material of solder joint, the materials of substrates(related the difference in CTE), the height of solder, the Distance of the solder joint from the Neutral Point (DNP), the temperatur...

Title of Dissertation: DEVELOPMENT OF MOIRÉ INTERFEROMETRY FOR REAL-TIME OBSERVATION OF NONLINEAR THERMAL DEFORMATIONS OF SOLDER AND SOLDER ASSEMBLY Seungmin Cho, Doctor of Philosophy, 2005 Dissertation Directed By: Associate Professor Bongtae Han, Department of Mechanical Engineering An experimental apparatus using moiré interferometry is developed to characterize the thermo-mechanical behavio...

In the past few years, many studies have reported on the formula of solder metal alloy materials. This paper discusses the influence of organic materials characters, the decomposing rate of flux in lead-free solder paste and coefficients of thermal expansion (CTE) of halogen-free mold compounds during the on-board reliability test, and the failure mechanism in both 63Sn/37Pb and Sn–3.5Ag–0.5Cu ...

The electronics industry is undergoing a materials evolution due to the pending Restriction of Hazardous Substances (RoHS) European Directive. Printed wiring board laminate suppliers, component fabricators, and printed wiring assembly operations are engaged in a multitude of investigations to determine what leadfree (Pbfree) material choices best fit their needs. The size and complexity of Pbfr...

Solder paste is a homogeneous, stable suspension of solder powder particles suspended in a flux binder, and is one of the most important process materials today in surface mount technology (SMT). By varying the solder particle size, distribution and shape, as well as the other constituent materials, the rheology and printing performance of solder pastes can be controlled. Paste flow behavior is...

Surface mount technology (SMT) is increasingly used in microelectronics to mount components by soldering onto the printed circuit board (PCB). The solder alloys are used as the electrical and mechanical connections between the component and the board. Fatigue failure of solder joints is recognized as a major cause of failure in electronic devices. An approach to this problem is to determine the...

Nano-sized, nonreacting, noncoarsening ZrO2 particles reinforced Sn–3.0 wt%Ag–0.5 wt%Cu composite solders were prepared by mechanically dispersing ZrO2 nano-particles into Sn–Ag–Cu solder. The interfacial morphology of unreinforced Sn–Ag–Cu solder and solder joints containing ZrO2 nano-particles with Au/Ni metallized Cu pads on ball grid array (BGA) substrates and the distribution of reinforcin...

Microstructure, wetting behavior and interfacial reactions between Sn–0.7Cu and Sn–0.3Ag–0.7Cu (SAC0307) solders solidified on Ni coated Al substrates were compared and investigated. Microstructure of Sn–0.7Cu alloy exhibited a eutectic matrix composed of primary β-Sn dendrites with a fine dispersion of Cu6Sn5 intermetallics whereas microstructure of SAC0307 alloy exhibited coarser Cu6Sn5 and f...

This paper presents an integrated flow-thermomechanical analysis of ansiothermal fatigue behavior of ceramic ball grid array (CBGA) solder joints in a 32mm C4/CBGA package under a mini power cycled load of one to three watts at a frequency of three cycles per hour. A computational fluid dynamics model was used for conjugate conduction-convection heat transfer analysis to determine the local hea...