This paper discusses the reliability testing results of a lead-free version of the micro SMD, National Semiconductor’s Wafer Level-Chip Scale Package (WLCSP). The micro SMD, a true wafer scale package has proven to be highly adaptable in the conventional assembly process, requiring no special considerations during the surface mount assembly operation. The current micro SMD utilizes standard Sn/...

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...

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...

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...

joining of titanium alloys to other materials especially steels has attracted much attention in recent years due to the exceptional properties of titanium such as excellent corrosion resistance and mechanical properties and its increasing application in various industries. according to the fe-ti binary phase diagram, these two elements do not have complete solubility. this leads to difficulties...

Abstract The Sn-4Ag-0.5Cu base solder adding 3 wt.% bismuth (SAC-3Bi) has better drop and thermal cycling performance than due the excellent mechanical properties in previous study. Therefore, SAC-3Bi applied joints of wafer level chip scale packaging (WLCSP) recent year. In this study, was used on WLCSP device to evaluate electromigration reliability. A specially designed test vehicle for ball...

Sn-Bi solder with different Bi content can realize a low-to-medium-to-high soldering process. To obtain the effect of Bi content in Sn-Bi solder on the microstructure of solder, interfacial behaviors in solder joints with Cu and the joints strength, five Sn-Bi solders including Sn-5Bi and Sn-15Bi solid solution, Sn-30Bi and Sn-45Bi hypoeutectic and Sn-58Bi eutectic were selected in this work. T...

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 Au/Ni-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...

Thermo-mechanical reliability of the solder bumped flip chip packages having underfill encapsulant was evaluated with thermal shock testing. In the initial reaction, the reaction product between the solder and Cu mini bump of chip side was Cu6Sn5 IMC layer, while the two phases which were (Cu,Ni)6Sn5 and (Ni,Cu)3Sn4 were formed between the solder and electroless Ni-P layer of the package side. ...