The underfilling BGA as an alternative to direct chip attachment for high density packaging technologies have been developed. This paper discusses the thermomechanical and metallurgical effects of underfill material and the resulting improvement in board level reliability for underfilled BGA assemblies. Finite element analysis (FEA) models were developed to predict the thermal fatigue life of t...

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...

Increasing environmental concerns and pending government regulations have pressured microelectronic manufacturers to find suitable alternatives to Pb-bearing solders traditionally used in electronics packaging. Over recent years, Sn-rich solders have received significant attention as suitable replacements for Pbbearing solders. Understanding the behavior of intermetallics in Sn-rich solders is ...

Solder joint reliability of SMT components connected to printed circuit boards is well documented. However, much of the testing and data is related to high-strain energy thermal cycling experiments relevant to product qualification testing (i.e., -55C to 125C). Relatively little information is available on low-strain, high-cycle fatigue behavior of solder joints, even though this is increasingl...

The influence of alloy composition of lowmelting Sn-Bi-Cu lead-free solder alloys on mechanical properties and solder joint reliabilities were investigated. The mechanically optimum alloy composition is Sn-40Bi-0.1Cu (mass%). The addition of 40mass%Bi improves the ductility and restrains the fillet-lifting, which are problems of lead-free solders with Bi. The addition of copper improves both th...

The failure modes of flip chip solder joints under high electrical current density are studied experimentally. Three different failure modes are reported. Only one of the failure modes is caused by the combined effect of electromigration and thermomigration, where void nucleation and growth contribute to the ultimate failure of the module. The Ni under bump metallization–solder joint interface ...

This paper presents the failure analysis results of board level drop tests. In this study, the test vehicle was designed according to the requirements of the Joint Electron Device Engineering Council (JEDEC) drop test board. The test vehicle was assembled with 15 chip scale packages (CSPs) each having 228 daisy-chained 0.5 mm pitch solder joints using Sn-3.0 wt% Ag0.5 wt% Cu (SAC305) lead free ...

The authors present a sensor for real-time detection of solder-joint faults in programmed, operational Field Programmable Gate Arrays (FPGAs), especially those FPGAs in Ball Grid Array (BGA) packages, such as a XILINX® FG1156 [1]. FPGAs are used in all manner and kinds of control systems in aerospace applications. The ability to sense high-resistance faults in the solder joints of operational F...

This paper describes the design and construction of an open automated solder bond veri cation machine for the electronics manufacturing industry The application domain is the higher end assembly technologies with an emphasis on ne pitch surface mount components The system serves a measurement function quantifying the solder bonds It interfaces with the manufacturing process to close the manufac...

Title of Document: CONSTITUTIVE PROPERTY TESTING AND RELIABILITY ASSESSMENT OF LEADFREE SOLDER JOINT Yuri Lee, Master, 2010 Directed By: Professor Bongtae Han, Department of Mechanical Engineering A modified single lap shear test configuration, based on the Iosipescu geometry, is proposed to characterize mechanical properties of solder alloys. In the method, an auxiliary device (extension unit)...