RELIABILITY ASSESSMENT OF SOLDER JOINT USING BGA PACKAGE – MEGTRON 6 VERSUS FR4 PRINTED CIRCUIT BOARDS

Abstract

When it comes to the mechanical and electrical seam of the Printed Circuit Board (PCB) and package, reliability of the board plays a major impact on PCB. As the frequency increases, losses in signals increase. This necessitates the use of new materials for such applications. Nelco 4000-13EPSI, Rogers 4350B, Panasonic Megtron 6 are few high-speed materials used. Studies have shown that Megtron 6 has the least dielectric losses so far, low transmission loss, high heat resistance and has low weight loss than the FR-4 boards. With an increasing demand for high performance, reliability and lower costs, the field of electronic packaging has a vast area to research on. Ball Grid Array (BGA), a type of Surface Mount Technology package has and continues to be used due to its robust design, improved performance, reduced package thickness and large number of pins on an efficient board area. As such, in this paper, we study reliability of BGA package on various boards. v In this work, we use Megtron 6 and FR4 circuit boards with BGA packages. A Dynamic Mechanical Analyzer (DMA) is used to obtain the time and temperature dependent viscoelastic properties of the boards while the Coefficient of Thermal Expansion (CTE) and glass transition temperatures are obtained from the Thermo-Mechanical Analyzer (TMA). The results obtained from characterization of both the boards are used to simulate Finite Element Analysis (FEA) model. ANSYS Workbench 18 is leveraged to study the life to failure of the package and its effect on the solder ball reliability using both the boards under different thermal loadings. We also compare the plastic work for these boards which play a significant role in the reliability of a package assembly.