This paper presents and discusses issues relevant to solidification of a chosen lead-free solder, the eutectic Sn-3.5%Ag, and its composite counterparts. Direct temperature recordings for the no-clean solder paste during the simulated reflow process revealed a significant amount of undercooling to occur prior to the initiation of solidification of the eutectic Sn-3.5%Ag solder, which is 6.5 C, ...

Solder joint fatigue failure is a serious reliability concern in area array technologies, such as flip chip and ball grid array packages of integrated-circuit chips. The selection of different substrate materials could affect solder joint thermal fatigue life significantly. The mechanism of substrate flexibility on improving solder joint thermal fatigue was investigated by thermal mechanical an...

This paper presents failure analysis of solder joints with a damage-coupled viscoplastic model. A material model is developed to characterize the elasticity, plasticity, creep and damage of solder. A semiimplicit time-integration approach is adopted for the numerical implementation of the solder model. This solder model has been implemented into nite element codes developed at Sandia National L...

The quality of surface mount technology (SMT) product solder joint was key factor for SMT products. In this paper, for chip components, a fuzzy fault diagnosis principle of SMT products was analyzed. And the total framework of fault diagnosis system was built based on solder joint shape theory. Geometrical shape parameters which reflected chip components solder joint quality were analyzed and d...

Au (0.05 μm) 69.4 μm Electromigration may affect the reliability of flip-chip solder joints. Eutectic solder is a two-phase alloy, so its electromigration behavior is different from that in aluminum or copper interconnects. In addition, a flipchip solder joint has a built-in currentcrowding configuration to enhance electromigration failure. To better understand electromigration in SnPb and lead...

Due to the consideration of environmental protection policy, all electronic products are requested to be lead free. In package field, solder ball is also requested to be lead free and currently the most popular type of solder ball is the Sn/Ag/Cu solder [1]. Sn/Ag/Cu solder has higher melting point and weaker wettability [2-3] during IR re-flow profile than eutectic solder ( Sn/Pb ), therefore ...

The trend to reduce the size of electronic packages and develop increasingly sophisticated electronic devices with more, higher density inputs/outputs (I/Os), leads to the use of area array packages using chip scale packaging (CSP), flip chip (FC), and wafer level packaging (WLP) technologies. Greater attention has been paid to the reliability of solder joints and the assembly yield of the surf...

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...

Introduction Intermetallic compounds (IMCs) are generally considered a bad thing in solder joints, though this is not always the case. Excessive IMCs in solder joints are a bad thing since they significantly alter both the composition and the mechanical performance of the solder joint. Interfacial IMC layers can be an indication of the quality of the solder joint and the lack of them would indi...

There is an increasing demand for replacing tin-lead (Sn/Pb) solders with lead-free solders in the electronics industry due to health and environmental concerns. The European Union recently passed a law to ban the use of lead in electronic products. The ban will go into effect in July of 2006. The Japanese electronics industry has worked to eliminate lead from consumer electronic products for s...