PhD Proposal by Omkar Gupte
THE SCHOOL OF MATERIALS SCIENCE AND ENGINEERING
GEORGIA INSTITUTE OF TECHNOLOGY
Under the provisions of the regulations for the degree
DOCTOR OF PHILOSOPHY
on Tuesday, April 21, 2020
will be held the
DISSERTATION PROPOSAL DEFENSE
"Modeling, Design and Demonstration of Innovative Surface-Mountable and Socketable Board-Level Interconnection Technology "
Prof. Rao Tummala, Advisor, ECE/MSE
Prof. Vanessa Smet, Co-advisor, ME
Prof. Preet Singh, MSE
Prof. CP Wong, MSE
Gregorio Murtagian, Ph.D, Intel Corporation
Ball Grid Array (BGA) architectures are being widely used in the semiconductor industry in surface mount (SMT) applications to satisfy the miniaturization needs of emerging microelectronics systems. However, these architectures are not compatible with socketing applications as the mechanical contact between the Au paddle and the solder sphere leads to undesirable reactions, increasing the contact resistance and degrading reworkability over time. To address this challenge, surface modification of BGA spheres with multilayered thin-film metallic coatings such as Ni-Au and Bi-Au is proposed to maintain a non-reactive noble metal interface when used in a socket. This proposal provides details of the studies conducted in this research, including (1) diffusion modeling and design of such coatings with a fundamental understanding of the trade-offs between SMT and socketing applications, (2) the development, characterization and optimization of the modified BGA balls coating and attach processes using an in-house developed, hybrid sputtering/electroless deposition process and conventional mass reflow with solder paste, respectively, as well as (3) thermal aging characterization of the modified BGA packages. These preliminary results establish the proposed approach as a promising technology towards the development of a reliable, universal BGA solution.