A novel and direct method to measure the stress-strain properties of surface mount solder joints is proposed in this paper. The specimen used in the experiments is a quad flat pack (QFP)-solder-printed circuit board (PCB) assembly and the fabrication of solder joints makes use of conventional surface mount technology (SMT). Mechanical cycling and thermal shock testing can be conducted directly ...

Surface-micromachined microelectromechanical systems (MEMS) are two dimensional in their “as fabricated” form. Surface-micromachined MEMS can be assembled after fabrication to realize systems with a more three-dimensional form and function. One reliable method of assembly, suited to commercial mass production, is to use the surface tension of microsized droplets of molten solder to assemble the...

The solder joint reliability of ceramic chip resistors assembled to laminate substrates has been a long time concern for systems exposed to harsh environments such as those found in automotive and aerospace applications. This is due to a combination of the extreme temperature excursions experienced by the assemblies along with the large coefficient of thermal expansion mismatches between the al...

Recent investigations have revealed that Pb-free solder joints may be fragile, prone to premature interfacial failure particularly under shock loading, as initially formed or tend to become so under moderate thermal aging. Depending on the solder pad surface finish, different mechanisms are clearly involved, but none of the commonly used surface finishes appear to be consistently immune to embr...

The research summarized in this paper will help to address some of the issues associated with solder paste mass reflow assembly of 0201 components. Attachment pad design, stencil design, component to component spacing, component orientation, flux type, and solder paste reflow atmosphere were the major variables researched during the project. The two major responses from the experimentation were...

b fast and highly reliable method of inspecting minule solder joints of high-density rnouaed devices hns been dcveloperl. It uses two techniques to detect all types of defects, such as unsoldered leads. solder bridges. and mis-aligned leads. One applieszxternal Form to solder joints with an air jet. which vibrates w shifts unsoldered leads. The vibration and shift is detected as a change in the...

Nanocomposite lead-free solders are gaining prominence as replacements for conventional lead-free solders such as Sn-Ag-Cu solder in the electronic packaging industry. They are fabricated by adding nanoparticles such as metallic and ceramic particles into conventional lead-free solder. It is reported that the addition of such nanoparticles could strengthen the solder matrix, refine the intermet...

In this paper the influence of the temperature cycle time history profile on the fatigue life of ball grid array (BGA) solder joints is studied. Temperature time history in a Pentium processor laptop computer was measured for a three-month period by means of thermocouples placed inside the computer. In addition, pentium BGA packages were subjected to industry standard temperature cycles and als...