Effect of solder pads on the fatigue life of FBGA memory modules under harmonic excitation by using a global–local modeling technique

Thermo-Mechanical Design and Validation of Spaceborne High-Speed Digital Receiver Unit for Synthetic Aperture Radar Application

“…Representative cycles to failure, failure mechanisms, and cross-sectional photomicrographs for these package assemblies under different thermal cycle regimes were investigated via thermal vacuum tests to simulate space environments. Using a global-local modeling technique, Cinar et al [3] investigated the effect of solder pad size on the fatigue life of fine-pitch ball grid array (FPGA) solder joints in memory modules triggered by harmonic excitation. The effectiveness of these technical approaches experimentally verified that the solder pad size in solder joints influences the fatigue life, as well as the reliability of solder joints under harmonic excitation.…”

BGA Interconnection Reliability in Mirrored Module Configurations

“…Interconnection dimensions are important because too long a route would cause timing problems and stray effects, such as unwanted inductance, whereas too short of an interconnection height can result in greatly reduced reliability lifetime. [4]- [6] Mirrored structures, where similar components are located on opposite sides of a PCB, have been studied for chip scale package (CSP)/BGA modules, and some finite element modeling (FEM) data along with test results can be found in the literature [7]- [12]. Mirroring causes challenges in the areas of design and material, such as  Increased stiffness due to restricted warpage of the PCB [7], [8], which can be considered the single major issue affecting the lifetime of interconnections in mirrored module configurations  Microstructural effects due to a second reflow process, i.e., extended growth of rigid and brittle intermetallic phases  Differing interconnection heights of mirrored components, depending on the number of reflows they have been through (top/bottom side) [9]  Irregular solder joint shape, voids, partial separation between the solder and the intermetallic layer [10] Some proposed solutions to mitigate the increased stress levels have been considered, those being  Offsetting the mirrored components [7], [8]  Using a thinner PCB [11]  Using more compliant materials and smaller components [8]  Redesigning the solder pad [12] BGA Interconnection Reliability in Mirrored Module Configurations Juha Hagberg, Jussi Putaala*, Juha Raumanni, Olli Salmela, Timo Galkin T This article presents the results of thermal cycling tests (TCT) and simulations of plastic BGA (PBGA) components mounted on one side (single side configuration) and different mirrored configurations on a PCB.…”

Optimal design of PBGA mixed solder joints under random vibration

“…Their results showed that solder joints with larger diameter and smaller height can improve vibration reliability. By using a global-local modeling technique on memory modules, Yusuf cinar et al [3] investigated the effect of solder pad size on the fatigue life of fine-pitch ball grid array solder joints under harmonic excitation. The result showed that with the pad size of PCB increasing from 0.33 to 0.35 in diameter, the average lifetime increased by about 32.7%.…”