The high cycle fatigue (HCF) cracking behaviors in the SnPb solder joints were investigated experimentally via in situ observations with scanning electron microscope (SEM). The results indicate that the HCF cracks incubate at the toe of the solder joints and propagate mainly along an angle from 20 to 45 tilted to the applied stress axis differing greatly from the propagation behaviors reported ...

Solder joints with Cu columns appear to be one of the best structures to resist electromigration. Three-dimensional thermoelectrical analysis was employed to simulate the current density and temperature distributions for eutectic SnPb solder bumps with 0.5, 5, 25, 50, and 100 lm Cu under bump metallization (UBM). It was found that the hot spots and current crowding effects in the solder were re...

Although many have predicted the demise of through-hole components, they are alive and well with tens of billions assembled each year. In many cases these components are assembled by wave soldering. However, in many mixed product technology (i.e. SMT and through-hole on the same board) products, it makes sense to consider assembling the through-hole components with the pin-in-paste (PIP) proces...

Experimental damage mechanics of flip chip solder joints under current stressing is studied using 20 test vehicle flip chip modules. Three different failure modes are observed. The dominant damage mechanism is caused by the combined effect of electromigration and thermomigration, where void nucleation and growth lead to the ultimate failure of the module. It is observed that thermomigration dri...

Solder alloys are widely used bonding materials in electronics industry. The reliability con‐ cerns for solder interconnections, which provide both mechanical and electronic connec‐ tions, are rising with the increasing use of highly integrated components in portable electronic products [1-6]. As shown in Fig. 1, a typical ball grid array (BGA) component board usually consists of a silicone die...

A thermal model of the infrared reflow process has been developed for an FR-4 card populated with an array of Solder Ball Connect (SBC) modules. The analysis of the threedimensional, transient, finite element model accounts for radiative exchange within the infrared oven and for the heat conduction (nonisotropic) within the modules and card. Transient temperature profiles of selected points and...

Wafer bonding has been widely used for forming vacuum and hermetic packages for MEMS devices. Several techniques, including anodic silicon-glass, silicon-silicon fusion, metal compression, glass frit, eutectic, and solder bonding have been attempted and some have been demonstrated successfully. Solders have some advantages that make them an interesting area of research for wafer bonding. They o...

Vibration testing was conducted by Boeing Research and Technology (Seattle) for the NASA-DoD Lead-Free Electronics Solder Project. This project is a follow-on to the Joint Council on Aging Aircraft/Joint Group on Pollution Prevention (JCAAlJG-PP) Lead-Free Solder Project which was the first group to test the reliability of lead-free solder joints against the requirements of the aerospace/mi Ii ...

Three types of inexpensive Pb-free solder joints, namely Zn-based and Bi-based solders, and a CuSn alloy were studied for application to the high-temperature operation of wide band-gap power semiconductor devices using GaN or SiC. Zn– Al solder sheets, whose melting point is 380°C were prepared, and then surface oxides were removed by RF plasma etching. Subsequently, Cu thin films were deposite...

Sn-Pb eutectic solder alloy is extensively used in microelectronics packaging interconnects. Due to the high homologous temperature, eutectic Sn-Pb solder exhibits creepfatigue interaction and significant time-, temperature-, stress-, and rate-dependent material characteristics. The microstructure is often unstable, having significant effects on the flow behavior of solder joints at high homolo...