Solder voiding is present in the majority solder joints and is generally accepted when the voids are small and the total void content is minimal. X-ray methods are the predominate method for solder void analysis but this method can be quite subjective for non grid array components due to the two dimensional aspects of X-ray images and software limitations. A novel method of making a copper “san...

Au over Ni on Cu is a widely used printed circuit board (PCB) surface finish, under bump metallization (UBM), and component lead metallization. It is generally accepted that less than 3 wt.% Au in Sn-Pb solder joints inhibits formation of detrimental intermetallic compounds (IMC). However, the criti­ cal limit for Au content in Pb-free solder joints is not well established. Three surface-mount ...

This paper investigates the failure mechanism of Fine-pitch Ball Grid Array (FBGA) solder joints of memory modules due to harmonic excitation by the experiments and the finite element method. A finite element model of the memory module was developed, and the natural frequencies and modes were calculated and verified by experimental modal testing. Modal damping ratios are also obtained and used ...

The joining of lead-free Sn-3.0Ag-0.5Cu (SAC305) solder alloy to metal substrate with the addition of a porous Cu interlayer was investigated. Two types of porous Cu interlayers, namely 15 ppi—pore per inch (P15) and 25 ppi (P25) were sandwiched in between SAC305/Cu substrate. The soldering process was carried out at soldering time of 60, 180, and 300 s at three temperature levels of 267, 287, ...

Microelectronic packaging plays an important role in cryogenic engineering; in particular, a solder joint as interconnection, which offers a mechanical, thermal and electrical support, undergoes much larger and harsher thermal changes during its service compared with conventional customer electronic products. The impact of thermo-mechanical properties of such solder joints under cryogenic servi...

As concerns of the environmental impact of lead waste increase, the electronics industry is coming under increasing pressure to reduce or eliminate the use of lead in their manufacturing processes. Circuit assembly providers consequently must develop alternatives to eutectic tin-lead solder for use in their operations. Many ramifications are likely, including an initial decrease in process yiel...

Traditional Sn-Pb solder alloys are being replaced, because of environmental and health concerns about lead toxicity. Among some alternative alloy systems, the Sn-Zn and Sn-Cu base alloy systems have been studied and reveal promising properties. The reliability of a solder joint is affected by the solder/substrate interaction and the nature of the layers formed at the interface. The solder/subs...

In the continuing effort to shrink the electronics components and assemblies, the need for streamlined production processes and quality assurance is emerging stronger than ever. Surface Mounted Devices (SMD) is one of the breakthrough techniques that drove printedcircuit board production to a new level, increasing substantially the component density and reducing the size of produced circuits. Q...

One of the main challenges facing the electronics manufacturing industry in solder paste printing for ultra-fine pitch surface mount and flip-chip assembly is the difficulty in achieving consistent paste deposit volumes from pad-to-pad. At the very small aperture geometries required for ultra-fine pitch and flip chip assembly, flow properties of the paste becomes one of the dominant factors in ...

Recent trends in reliability and fatigue life analysis of electronic devices have involved developing structural integrity models for predicting the operating lifetime under vibratory and thermal environmental exposure. Solder joint reliability is the most critical issue for the structural integrity of surface mounted electronics. Extensive research has been done on thermal behavior of solder j...