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

Abstract

In electronic industry Ball grid array (BGA) package, surface mount technology has been used widely, due to its robust design, high density connections and improved performance. In surface mount technology, solder joints are used to interconnect package and PCB board assembly. High frequency laminates use in PCB boards provides excellent performance for high speed, frequency devices. Nelco 4000-13EPSI, Panasonic Megtron 6, and Rogers 4350B are few popular laminates. Component size reduction and structural complexity because of increasing number of transistors are making it very difficult to protect the packages from mechanical, thermal, and electrical damage. Difference in material properties between PCB board and package like coefficient of thermal expansion(CTE) generates excessive warpage, solder mask cracking, and bump cracking generally at the solder ball and package or solder ball and PCB board interface. Therefore, board level reliability(BLR) testing of these devices under thermal, and mechanical loading has because most important task. It includes temperature cycling, thermal shock, drop test, vibration, and mechanical bending test. The percentage of failure due to mechanical stress generation is much more then thermal loading. Board level drop testing has been used widely to study effect of mechanical impact loading. Finite elemental modeling software Ansys 16.1 is use because of complexity, high cost and time requirement of experimental method. Input G method is used for dropping testing analysis imitates all the conditions of physical test model. In this study performance of high frequency laminates FR4 and Megtron6 board with BGA package has been compare based on maximum peeling stress, strain rate and deformation magnitude.