An investigation on the solder bumped Flip Chip on Printed Circuit Board (FCOB) is presented in this paper. The emphasis is placed on the effects of delamination crack between the underfill encapsulant and the solder mask on the solder joint reliability of FCOB. In the present study, a fracture mechanics approach is employed. The strain energy release rate at the crack tip between the underfill...

Vibration fatigue test and analysis methodology for flip chip solder joint fatigue life assessment have been developed by performing vibration tests with constant G-level and varying G-level input excitation. The linear cumulative damage analysis method (Miner’s rule) predicts non-conservative result for vibration fatigue life of flip chip solder joint. Finite element analysis (FEA) using a glo...

A solder fatigue model for the 63Sn/Pb solder alloy has been previously introduced which characterizes the creep fatigue phenomena of the solder by combining nonlinear finite element modelling with experimental thermal fatigue lives of various flip chip assemblies. The model correlates the amount of creep strain energy dissipated per thermal cycle with the characteristic Weibull life of the cri...

In response to increasing environmental concern over the use of chlorofluorocarbons (CFC's) to clean printed circuit assemblies, many surface mount operations are converting to water soluble or no-clean type solder pastes. Current trends indicate that this conversion will progress rapidly until water soluble and no-clean pastes constitute the majority of the product mix. With the introduction o...

One of the challenges in an experimental study of solder joint reliability is to determine when cracks occur in a solder joint or when a solder joint fails. Cracks in a real solder joint are difficult to identify using an X-Ray system. Cross-sectioning and scanning electron microscopy (SEM) is a destructive method. A common non-destructive test method is to monitor resistance increase in a sold...

Interfacial reactions and shear properties of the In-48Sn (in wt.%) ball grid array (BGA) solder joints after bonding were investigated with four different surface finishes of the substrate over an underlying Cu pad: electroplated Ni/Au (hereafter E-NG), electroless Ni/immersion Au (hereafter ENIG), immersion Ag (hereafter I-Ag) and organic solderability preservative (hereafter OSP). During bon...

An accelerated thermal cycle experiment comparing similarly constructed area array devices representing Land Grid Array (LGA) and Ball Grid Array (BGA) technology with 0.254, 0.30, and 0.40mm diameter SAC305 solder balls was performed. The devices were subjected to three thermal cycle conditions in order to promote 2nd level solder fatigue. Failure data was compared using Weibull analyses. The ...

An automated visual inspection system has been developed for use with surface mount devices (SMDs) on a printed circuit board (PCB). The system is capable of inspecting minute solder joints of fine pitch components as small as 0.3mm pitch QFP leads. A solder joint is judged using a height image and an intensity image that are detected by a unique confocal height sensor. A solder joint is classi...

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...

SnAgCu is one of the most promising candidates for lead-free solders to replace conventional eutectic SnPb solders. The effects of solder volume on interfacial reactions and microstructure evolution in Ni/Au-SnAgCu-Ni(P) solder joints have been investigated under soldering and thermal aging conditions. The results show that solder volume has a strong effect on the formation of Au-containing int...